Dissertations / Theses on the topic 'Corylus avellana'

Magíster en Estrategia Internacional y Política Comercial
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La presente investigación tuvo como fin hacer una prospección del comercio del fruto seco del Avellano Europeo, desde el punto de vista del comercio internacional. Se realizó como memoria de grado y se presenta dividido en 3 partes-capítulos: la primera parte tiene como objetivo el presentar los antecedentes de la comercialización del avellano europeo producido en Chile; el segundo capítulo está enfocado al comercio internacional del fruto del avellano europeo, separando entre las avellanas con cáscara y avellanas sin cáscara, y el tercer capítulo se orienta a las variables críticas que intervienen en el proceso de comercialización de este producto. La información para la realización del presente trabajo fue recopilada acudiendo a las fuentes tradicionales de información, entregada por organismos públicos y privados y también a través de entrevistas con participantes del negocio de avellanas y personas de los organismos públicos como el Servicio Agrícola y Ganadero (SAG). El presente estudio determinó que son tres las variables críticas más importantes que influyen en el comercio de este producto. Estas son: rendimiento de la fruta que determina su comercialización en forma de con cáscara o sin cáscara, restricciones fitosanitarias que existen en los principales países importadores del avellano con cáscara y condición arancelaria y los TLC. El avellano europeo es un producto emergente, cuyas variables críticas representan los principales desafíos para el desarrollo de la industria y consolidación del fruto seco en la canasta exportadora chilena.

The difficulty of increasing taxane production and reducing its costs has prompted a search for new biotechnological sources. The unexpected discovery of taxanes in Corylus avellana has generated considerable interest in studying this plant and its derived cell cultures. We therefore focused this work on the study of cell suspension cultures of C. avellana as a new biotechnological approach to the production of taxol and related taxanes. With this goal, we optimized a scale-up process, the type of elicitor and moment of elicitation, cell culture growth, and an analytical technique to detect the compounds of interest. Also, C. avellana tree extracts were analyzed, leading to the identification of compounds with antiproliferative activity against cancer cell lines. These results provide new insights into cell suspension cultures of C. avellana and how to increase taxane production.
La dificultat d’incrementar la producció de taxans i de reduir els seus costos ha promogut la cerca de noves fonts biotecnològiques. El fet de trobar taxol i taxans a Corylus avellana ha incrementat l’ interès en el seu estudi. Per aquesta raó, hem focalitzat aquest treball en trobar noves estratègies per la producció de taxans en suspensions cel•lulars de C. avellana. Amb aquest objectiu, hem optimitzat el procés d’escalat, l’elicitació i el creixement dels cultius, així com la tècnica analítica per identificar i quantificar els compostos d’interès. A més, hem estudiat diversos extractes de l’arbre, fet que ens ha permès trobar altres compostos amb activitat antiproliferativa en línies cel•lulars cancerígenes. Tots els resultats proporcionen noves eines pel cultiu de suspensions cel•lulars de C. avellana i per a l’increment de la producció de taxans.

L'assecatge i emmagatzematge de l'avellana són processos molt importants en la
tecnologia postcollita de l'avellana que poden influir en la seva qualitat i idoneïtat per al
consum. Aquesta Tesi estudia la cinètica d'assecatge i la influència de les condicions
d'assecatge i frigoconservació sobre la qualitat de l'avellana; prèviament, però, es fa un estudi
del comportament higroscopio de l'avellana.
Per a l'estudi del comportament higroscòpic de l'avellana s'han determinat les corbes
de rehidratació i les isotermes d'humitat d'equilibri a diferents temperatures. L'equació de
Peleg dóna un bon ajust a les corbes de rehidratació; mentre que dels diferents models
matemàtics als que s'han ajustat les dades experimentals d'humitat d'equilibri, l'equació de
G.A.B. és la que prediu millor les isotermes d'humitat d'equilibri de l'avellana.
L'estudi de la influència de les condicions de frigoconservació sobre la qualitat de
l'avellana en gra s'ha fet emmagatzemant, durant un any, mostres d'avellana de les varietats
Negret, Pauetet i Tonda Romana a temperatures entre 0°C i 10°C i a humitats relatives de
40% i 60%. Per avaluar la qualitat de l'avellana emmagatzemada s'ha determinat l'índex
d'acidesa, els coeficients d'extinció K232 i K270, el període d'inducció, l'activitat dels enzims
lipasa, peroxidasa i polifenoloxidasa, l'evolució del color i l'acceptació organoléptica de
l'avellana. Els resultats obtinguts posen de manifest que la conservació de l'avellana en
aquestes condicions de frigoconservació és bona.
Per a l'estudi de la influència de les condicions d'assecatge sobre la qualitat de
l'avellana s'han realitzat experiències d'assecat amb avellana de la varietat Negt'et en gra i en
closca i amb avellana de la varietat Pauetet en gra, a temperatures entre 30°C i 80°C, i s'ha
determinat el grau d'alteració de la fracció lipídica i l'evolució del color de l'avellana. Els
resultats obtinguts indiquen que les temperatures d'assecat superiors a 50°C afavoreixen el
desenvolupament dels enranciments hidrolític i oxidatiu.
En darrer terme, s'ha estudiat la cinètica d'assecat de l'avellana ajustant les corbes
d'assecat en capa prima a diferents equacions. També s'ha realitzat la validació de l'algoritme
de simulació de l'assecat d'avellana en llit profund que utilitza el model de Nellist i l'equació
de velocitat d'assecat de Page, mitjançant la realització d'experiències d'assecat industrial
d'avellana.

The anatomy of bifurcations in trees requires further scientific investigation as the current anatomical model for them is logically flawed. The provision of a better model will assist in scientific studies of woody plants, the risk assessment of junctions in mature trees and provide bio-inspiration for Y-shaped joints in composite materials. In this study, the xylem formed in the central axis of a hazel (Corylus avellana L.) bifurcation is shown to provide a disproportionately greater amount of its tensile strength. CT scanning identified that this centrally-placed xylem was 28.1% denser, with 63% less vessels formed in this tissue, such vessels being 50.5% of the diameter and 32.5% of the length of those formed in adjacent stem tissues. The wood grain pattern at the bifurcation apices were 22 times more tortuous, forming interlocking patterns that acted to resist tensile forces by requiring the extraction or breaking of wood fibres along their length (the axial tensile strength of wood). Subsequent tests confirmed that this conferred more than 100% additional tensile strength to these specialised xylem tissues. These findings provided the basis of a novel anatomical model for bifurcations in woody plants. Further to this, the effects of several factors upon junction strength and biomechanical behaviour were assessed in bifurcations of hazel, identifying the weakening effect of bark inclusions and three types of artificial modification as well as differences in wind-induced movement between bifurcation types. This study concludes that further investigations of bifurcations in a wider range of woody plants and observations of the developmental stages of the interlocking wood grain patterns found at bifurcations would usefully add to existing knowledge.

During the 1990s, a question posed by new and intending growers of hazelnuts was “What is the best variety to plant when establishing a commercial orchard?” Although existing growers had a range of views on this matter, there had not been any scientific studies to evaluate the range of cultivars available in Australia. Although hazelnut cultivars were introduced to Australia in the mid-Nineteenth Century, there had been very limited industry development compared to other cool climate deciduous tree crops such as pome and stone fruits. In the 1970s many cultivars were imported from overseas, but there was no systematic evaluation of this material. In 1994, the author of this thesis obtained a grant from the Rural Industries Research and Development Corporation (RIRDC) to undertake an assessment of hazelnut cultivars and their potential for Australian conditions. The evaluation involved planting a range of cultivars at 5 field sites. Two were in New South Wales, 2 in Victoria, and 1 in Tasmania. There was variation between the sites in soil types and climate. A randomised block design was used with cultivars as treatments within blocks. Observations and measurements were recorded for tree growth, floral phenology, nut yields and the characteristics of both nuts and kernels. All sites had supplementary irrigation and common management practices. 1-year old hazelnut whips were planted at a spacing of 3 m x 5 m. Automatic weather stations were located at each site. There were major differences between cultivars, in terms of their vigour of growth, floral phenology, nut yields and kernel characteristics. In addition to the cultivar effects, soil type was a major factor influencing tree growth, as was rainfall. Cultivars with high vigour included ‘Barcelona’ and the Australian selection ‘Tokolyi/Brownfield Cosford’ (‘TBC’). Those of low vigour were ‘Tonda Gentile delle Langhe’ (‘TGDL’), ‘Negret’ and ‘Wanliss Pride’. There were significant interactions between cultivars and the sites in tree growth and nut yields. Timing of male and female anthesis was strongly influenced by cultivar and seasonal conditions. All cultivars were protandrous. The commencement of pollen shed ranged from late-May, for the cultivars ‘TGDL’ and ‘Barcelona’, to early August for ‘Hall’s Giant’. Chill hour requirements appeared to be the main factor influencing timing of pollen shed. Female anthesis was also spread over a period of several weeks with early cultivars being ‘Atlas’ and ‘Tonda di Giffoni’, late cultivars were ‘Ennis’, ‘Casina’ and ‘Hall’s Giant’. Studies with cut branches in controlled temperature environments indicated that catkins had a relatively high post-chill heat requirement compared to female inflorescences. The differences between cultivars in post-chill heat requirements for catkins were small. The relative dates of flowering across cultivars were found to be highly predictable. This, coupled with published data on genetic incompatibility, made it possible to recommend cultivars as pollinisers for the main nut-yielding cultivars. There were significant differences between cultivars in the date of bud break; ‘TGDL’ and ‘Tonda di Giffoni’ were early (late August) whereas ‘Hall’s Giant’ was late (late September). Nut yields were highly influenced by cultivar, vigour of growth, site and seasonal rainfall. Low rainfall in one season greatly reduced nut yields. High growth rates at one site lead to a closed canopy 7 years from planting with peak yields. Soil characteristics were a main factor influencing tree growth and nut yields. The best tree growth and highest levels of production were achieved on a deep, well drained, fertile loam soil. The characteristics of nuts and kernels were strongly influenced by cultivar, although seasonal conditions influenced nut and kernel size and the degree of kernel fill. An overall evaluation of cultivars was based on nut and kernel yields as well as kernel characteristics to meet market requirements. On average, ‘Ennis’ gave the highest yields of the in-shell cultivars. The cultivars ‘Barcelona’ and ‘TBC’ produced the highest average yields, although their relative performance varied between sites. These cultivars were considered best suited for snack foods and catering with 15-17 mm kernels. ‘Tonda di Giffoni’ produced moderately high yields, varying across sites, with kernels suitable for the confectionery market. Under favourable conditions ‘Barcelona’ achieved nut yields of 3 tonnes/ha within 6 years from planting. Potential areas in Australia for hazelnut production were identified, based on a set of recommended climatic parameters and soil characteristics.

Hazelnuts are mostly non-dormant at harvest but develop seed dormancy after a few days of storage. The seeds have been classified as recalcitrant since they cannot be stored for more than one year under ambient conditions. Cryopreservation has not been satisfactory so an alternative protocol is required. To test for recalcitrance, chilled non-dormant seeds (control) were compared with gibberellic acid (GA3) treated seeds during 6 weeks storage at 5°C or at ambient temperature. Control seed moisture content (MC) was 14-15% compared with 20% for GA3 treated seeds. No change in viability was noted until the end of 6 weeks at ambient temperature, when infection proliferated. Reduced germinability, associated with increased leachate conductivity, was noted on all treatments and controls, with ambient temperature storage most harmful for seed viability. This supports classification of hazel seeds as recalcitrant. However, orthodox behaviour could be induced by reducing seed moisture to <6%, showing survival for more than 3 years at -20°C with acceptable germinability and producing healthy seedlings. Pathogen tests show that 6 weeks chilling to break seed dormancy may activate the seeds’ internal protective mechanisms, thereby reducing infection and enabling germination and healthy seedling establishment. The link between seed viability and protection from free radicals and pathogens was examined. Antioxidant activity in hazelnut seed associates (such as endocarp, funiculus and testa) was found to be much higher than in the seed embryo, perhaps indicating that hazel seeds have natural protective mechanisms within the pericarp. Antioxidant activity of seed associates increased during chilling, indicating their role in protecting the seed. Nevertheless, TTC test revealed that seeds acclimatised to ii < 6% MC and stored at 5°C for 45 weeks showed viability loss due to damage of the embryonic axes, probably caused by free radicals. Initial tests to stabilise seed moisture content showed that reduction in seed moisture did not impose dormancy and seed moisture content (MC) stabilisation resulted in > 80% germination but many abnormal seedlings. Dormancy reversibility was tested by treatments T1 (one period at 15°C) and T2 (two periods at 15°C), designed following a consideration of the natural environment. Both resulted in reduced germination, delayed seedling emergence, increased abnormal seedlings, reduced seedling height and decreased internode numbers. To test the role of temperature in reduced seed performance, non-dormant hazelnuts were held at either 5°C or at ambient temperature for up to 6 weeks. Seeds from both sets exhibited high viability, but germinability was significantly decreased in the ambient temperature set, associated with increases in leachate conductivity and infection. Work in this thesis has confirmed that dormancy was broken by chilling, with gradually increasing germination as chilling time was increased. Germination increased with increase in chilling and reduction in infection. No infection was recoreded after 6 weeks chilling. It is most likely that protective agents are produced causing suppression of infection. In these experiments it was observed that not all germinated seeds produced healthy seedlings, suggesting that germination tests without observation of seedlings may give an incomplete assessment of germination success. Assessment using the Tetrazolium test (TTC) was found to be much more dependable and it was also possible to detect damage to specific tissues that might result in unhealthy seedlings.

El manejo del agua en plantaciones frutícolas, o arbóreas, requiere un profundo conocimiento de la respuesta del árbol a diferentes situaciones de estrés hídrico, y de como r í · '"·', ; las posibles técnicas de aplicación de agua de riego y las condiciones del medio (principalmente suelo y agua) donde se encuentra ubicada la plantación, pueden condicionar la disponibilidad de agua para la planta. Con la finalidad de profundizar y ampliar este tipo de conocimientos se ha desarrollado el " *' presente trabajo. Para su realización se han elegido tres especies (melocotón, avellano y nogal), y tres temáticas relacionadas con el agua: sensibilidad estacional al déficit hídrico (y en consecuencia la aplicación de estrategias de riego deficitario controlado (RDC)), ecofisiología de las relaciones hídricas e intercambio de gases y calidad del agua de riego. Con ello se pretende abarcar varios aspectos de la respuesta de los árboles frente a posibles estreses hídricos. Los resultados obtenidos nos permiten observar la especificidad de la respuesta productiva y fisiológica que cada caso estudiado en la relación "especie:condiciones del medio" nos aporta. En el caso del melocotonero (Capítulos I y II) sometido a calendarios de riego deficitario controlado se ha visto la importancia que el tipo de suelo tiene en la aplicación de estas estrategias, y como este factor condiciona el intercambio de gases, el estado hídrico de la planta y la evolución del crecimiento del fruto y cosecha. En este sentido es de remarcar el incremento en la capacidad fotosintética experimentada por los melocotoneros de la variedad "CalRed" que estuvieron sometidos a un tratamiento de riego deficitario controlado. En el estudio de los dos temas de avellano (Capítulos III y V) se pone de manifiesto la alta sensibilidad que este cultivo presenta a las situaciones de déficit hídrico especialmente al déficit parcial de presión de vapor y a la falta de agua durante la fase de crecimiento del fruto. En este mismo cultivo se ha observado una fuerte influencia varietal el comportamiento de los parámetros fisiológicos analizados en este trabajo. Destacándose la necesidad de cubrir los requerimientos hídricos de esta especie en las fases de llenado de frutos. Finalmente se estudia la sensibilidad del nogal (Capítulo IV) a la toxicidad del NaCl presente en el agua de riego. Todos los parámetros analizados (consumo de agua, intercambio de gases, crecimiento, desarrollo foliar, necrosis, etc.) detectan una gran sensibilidad de esta especia a la presencia de NaCl en al agua de riego y se detecta que no existe ningún mecanismo aparente de exclusión eficiente como para mitigar los daños observados.

Plants are unquestionably at the basis of human life as they are directly or indirectly a source of food, but the agricultural sector accounts for more than 80% of water consumption. Agricultural production cannot ignore water supply to meet market demands, while it faces growing water shortages, droughts and heat waves. In this sense, it is paramount to manage water resources in a sustainable way by understanding the water responses of species to different climates. The European hazelnut is an expanding orchard tree, which has now established in all continents to answer the increasing demand for nuts from the food industry. Trees face the challenge of acclimating to new areas, while remaining productive. In this situation, still no precise knowledge exits about the average transpiration of hazelnut orchard under standard irrigation and thus about the real irrigation needs respect to its environment. The few studies on hazelnut water use are mainly leaf-based or hardly transferred to growers. This research focuses on three main topics in the perspective of providing useful reference for orchard managers set in different climatic contexts: I) to identify the pattern of transpiration response to different climates, irrigation and cultivars. II) To estimate the transpiration at the tree level and propose a realistic tool for growers to reintegrate water loss. III) Explore the links and limitations of transpiration activity and carbon gain processes. We set a long-term experiment across three growing seasons (from 2016 to 2019) on eight orchards in Chile, Australia, Italy, France and Republic of Georgia, involving two cultivars: Tonda Gentile delle Langhe and Tonda di Giffoni. We monitored in continuous the sap flow with Granier’s thermal dissipation probes (TDPs), the meteorological parameters and the soil water content. Tree biometrics and orchard features were recorded as well. TDPs were calibrated with a liquid flow meter applied to a potometric system. The transpiration responses showed to be linearly correlated to the vapor pressure deficit of the atmosphere (VPD) until 20hPa. The radiation intensity produced different responses in the two hemisphere, but cultivar and doubled irrigation had little impact. The calibration of TDPs lead to the correction of the Granier’s equation with parameters suitable for hazelnut. This, together with the estimation of the tree leaf area, allowed to derive a range of transpiration per unit of leaf (1-2.55 l m-2day-1). This is the basis for a water loss reintegration strategy by knowing the mean daily VPD. The link between transpiration and carbon assimilation was considered to highlight the interval of VPD at which the canopy conductance, and thus the potential carbon assimilation, is maximized. A conclusive ancillary study shows through the manipulation of C sources and sinks that the nut production depends on C previously stored in the stem showing that branches are not fully carbon autonomous.
Le piante sono indiscutibilmente alla base della vita umana poiché sono direttamente o indirettamente fonte alimentare, ma il settore agricolo pesa per più dell’80% sul consumo di acqua. La produzione agricola non può prescindere dall’apporto idrico per raggiungere le richieste del mercato, mentre deve fronteggiare una crescente scarsità di acqua, eventi siccitosi e ondate di calore. In questo senso, diviene fondamentale gestire le risorse idriche in modo sostenibile comprendendo le risposte idriche delle specie ai diversi climi. Il nocciolo è un albero da frutto in grande espansione, che si è oggi affermato in tutti i continenti in risposta alla richiesta di nocciole da parte dell’industria alimentare. I noccioli debbono al contempo acclimatarsi alle nuove aree e rimanere produttivi. In questa situazione non c’è ancora una precisa conoscenza rispetto alla traspirazione media di noccioleti irrigati e quindi alle loro necessità irrigue calate nel contesto climatico. I pochi studi sull’ utilizzo dell’acqua nel nocciolo rimangono relativi alle dinamiche fogliari o sono difficili da trasferire agli agricoltori. Lo scopo di questa ricerca verte su tre scopi principali nella prospettiva di essere un riferimento per i gestori dei corileti che operano in diversi contesti climatici: I) Identificare la risposta traspirativa di piante adulte in diversi climi, irrigazioni e cultivar. II) Stimare la traspirazione al livello di albero e, sulla base di ciò, proporre un approccio realistico per reintegrare le perdite traspirative volto ai corilicoltori. III) Esplorare le connessioni e le limitazioni alla traspirazione e ai processi di acquisizione del carbonio. Si è installato un esperimento a lungo termine attraverso tre stagioni vegetative (2016-2019) in otto diversi corileti in Cile, Australia, Italia, Francia e Repubblica della Georgia, coinvolgendo due cultivar: Tonda Gentile delle Langhe and Tonda di Giffoni. Il flusso di linfa è stato monitorato con delle sonde a dissipazione termica di Granier (TDP). Sono stati misurati parametri meteorologici, contenuto idrico del suolo e parametri biometrici dei corileti. I TDP sono stati calibrati attraverso un misuratore di flusso e un approccio potometrico. Le risposte traspirative si sono dimostrate linearmente correlate con il deficit di pressione di vapore atmosferico (VPD) fino a circa 20 hPa. L’intensità di radiazione si è anche rivelata importante nel diversificare le risposte tra i due emisferi, ma la cultivar e le diverse strategie irrigue hanno avuto un effetto irrilevante nel diversificare le risposte traspirative. La calibrazione dei TDP ha condotto alla correzione dell’equazione di Granier con parametri adatti al nocciolo. Questo, insieme alla stima dell’area fogliare ha permesso di individuare un intervallo di traspirazione per unità di area fogliare (1-2.5 l m-2 giorno-1). Tale risposta è alla base di una strategia di reintegro delle perdite traspirative che utilizza il VPD medio come principale predittore della traspirazione totale giornaliera. Il legame tra traspirazione e assimilazione potenziale di carbonio è stato considerato per far emergere l’intervallo di VPD in cui la conduttanza di chioma è massimizzata, e quindi, anche il potenziale di assimilazione. Uno studio ancillare conclusivo mostra che per il riempimento delle nocciole la specie utilizza anche carboidrati precedentemente immagazzinati nel fusto oltre che a quelli forniti dalle foglie dell’anno.

Magistro darbe tiriama paprastojo lazdyno formų: “X”, “Aurea”, “Fuscorubra” ir paprastojo lazdyno (Corylus avellana L.) mikrodauginimo in vitro sąlygos, bei augalų – regenerantų išauginimas. Darbo objektas – paprastojo lazdyno tiriamosios formos: “X”, “Aurea”, “Fuscorubra” ir paprastasis lazdynas (Corylus avellana L.). Darbo metodai – eksplantų parinkimas, paruošimas ir sodinamosios biologinės medžiagos išsterilinimas. Maitinamosios terpės eksplantų auginimui ir rizogenezei parinkimas. Eksplantų prigimties įtaka morfogenezei audinių kultūroje. Genotipo įtaka augalų regeneracijai audinių kultūroje. Auginimo salygų in vivo nustatymas. Darbo rezultatai. X lazdyno ir paprastojo lazdyno eksplantus siūloma sterilinti bet kuriuo iš tirtų metodų. Raudonlapio lazdyno eksplantus rekomenduojame sterilinti metodu Nr. 2, kai veiklioji medžiaga - H2SO4 85 , o geltonlapio lazdyno eksplantus - metodu Nr. 1 su AgNO3 0,1 . Visų genotipų lazdyno pumpurams sterilinti netinka sieros rūgštis (85 ). Paprastojo lazdyno formoms dauginti in vitro būdu tinkamiausia modifikuota WPM I varianto maitinamoji terpė, o paparastajam lazdynui - modifikuota WPM III varianto maitinamoji terpė. Corylus genties morfogenezė audinių kultūroje priklauso nuo genotipo. Genotipas taip pat turi įtakos susidariusio kaliaus spalvai. Daugiausiai eksplantai paaugo nuo 10 iki 20 dienos. Geriausius rezultatus pasiekė X lazdyno genotipas, nes paaugo nuo 3 iki 26 mm. Kultivuojant in vitro sąlygomis, geltonlapio lazdyno... [toliau žr. visą tekstą]
Micropropagation in vitro conditions and the production of plants – regenerants of hazel forms "X", "Aurea", "Fuscorubra" and plain hazel (Corylus avellana L.) are investigated in the work of master science. Objectof the work - hazel test forms "X", "Aurea", "Fuscorubra" and plain hazel (Corylus avellana L.). Methods of the work - Explants selection, preparation and sterilization of planting biological material. The choice of nutrient medium for explants cultivation and rhizogenesis. Impact of explants nature on the morphogenesis in tissue culture. Genotype influence to the regeneration of the plant in tissue culture. Determination of the conditions of in vivo cultivation. The results of the work. “X” form and plain hazelnut explants are suggest to be sterilized using method No 2, the active ingredient - 85 H2SO4, "Aurea" hazel explants - method No 1, with AgNO3 0,1 . Modified WPM I nutrient medium is the best version for in vitro propagation of the hazel forms, modified version of the WPM III nutrient medium – for plain hazelnuts. Morphogenesis of the Corylus genus in tissue culture depends on the genotype. Genotype also affects the color of the callus formed. Explants grew most in the period of 10 - 20 days. Best results were achieved by “X” hazelnut genotypes which grew from 3 to 26 mm. During the cultivation in in vitro conditions "Aurea" hazelnut explants did not form the yellow plates. The other 3 genotypes were more than 50  of identical micro shoots. “X”... [to full text]

La tesi Doctoral, de la que ara se‟n presenta un compendi resumit, manté com a fil conductor l'aplicació eficient de l'aigua de reg a nivell de parcel·la agrícola. El maneig de l'aigua a l'agricultura, sector productiu que usa el més alt percentatge d‟aquest element (77,5%), és fonamental si es vol incidir favorablement sobre el consum i l'actual política hidràulica, més orientada a un increment de l'oferta que a un control de la demanda. L'elecció d'un sistema de reg eficient, com és la microirrigació, amb un disseny adequat a les circumstàncies intrínseques de la parcel·la, seran decisius en aquest sentit. No obstant, l'estudi de tots aquells aspectes que optimitzin el funcionament de la instal·lació, des del punt de vista d‟aplicació, requereix, prèviament, conèixer com es mou i com es distribueix l'aigua en el perfil del sòl.. L‟avaluació de la forma i mida del volum del sòl humit (VSH) no és un aspecte menor ni tampoc fàcil de dur a terme, essent la majoria de vegades oblidat durant el procés del disseny. Les comptades recomanacions existents al respecte, quasi sempre es refereixen a la superfície del sòl mullat i en rares ocasions al VSH, encara que l'exploració radicular en el cultius, habitualment, adopta formes volumètriques. Tenint en consideració aquests antecedents i davant la falta d'informació existent sobre les característiques del VSH i de la seva possible influència sobre el comportament dels cultius, es plantegen dos objectius generals: 1) Dissenyar un Equip Mesurador del Volum de Sòl Humit (EMVSH), verificat a laboratori i a camp, i 2) Determinar la influència del percentatge de VSH en tres espècies arbòries com són l'olivera (Olea europaea L.), la pomera (Malus domestica BORKH) i l'avellaner (Corylus avellana L.) Respecte al primer objectiu, el disseny del EMVSH es basa en el concepte segons el qual l'aigua posseeix molècules amb una distribució desigual de la càrrega elèctrica i un comportament polar que facilita el pas del corrent elèctric. Quan augmenta el contingut hídric d'un medi porós, com el sòl, millora el flux de corrent a través d'ell. Contràriament, quan disminueix aquest contingut hídric, disminueix el flux de corrent i augmenta la resistivitat (ρ). Així mateix es considera la clara influència de la temperatura del sòl sobre el valor de la resistivitat de tal manera que la disminució d‟aquella ocasiona l'increment de la resistivitat elèctrica i viceversa. Fruit de diversos assaigs al laboratori aplicant les metodologies de prospecció geoelèctriques i més concretament la de Wenner, basada en l'avaluació directa de la resistivitat elèctrica (ρ), es va dur a terme el disseny del EMVSH. La fiabilitat del EMVSH, respecte a la seva capacitat per definir la forma i mida del VSH, s‟ha verificat a nivell de laboratori en condicions simulades i en camp mitjançant sis proves en sòls caracteritzats taxonòmicament en els termes municipals de Flix i Bovera (Tarragona i Lleida). En les proves de camp, estadísticament dissenyades, es varen establir sis tipus d‟irrigadors amb temps variables d‟aplicació. Les seccions verticals generades en aquestes proves indiquen l‟existència de tres fases en el desenvolupament del VSH: 1) Fase d‟avenç amb predomini de desplaçament vertical 2) Fase d‟emplenament i 3) fase de saturació amb predomini de desenvolupament horitzontal.
S‟ha observat una bona correlació entre el volum d‟aigua total aplicada per a cada irrigador respecte al seu radi mullat a 30 cm de fondària i al VSH que es genera. També s‟observa una correlació entre l‟àrea mullada (m2) a 30 cm i VSH (m3) que es genera, si es consideren els valors mitjans assolits pels diferents irrigadors per als diferents sòls de l‟àrea estudiada. La relació entre el radi mullat a 30 cm i la fondària màxima on ha arribat el VSH presenta valors pròxims a 0.8 (formes esfèriques) en els irrigadors de baix cabal (2.5- 5 l/h) i valors superiors a 1 (formes el·lipsoides) en els irrigadors de més cabal (8, 24 i 35 l/h). En relació al segon objectiu, s‟ha estudiat el VSH necessari i suficient que, avaluat mitjançant el EMVSH, proporcionarà el millor comportament agronòmic dels tres cultius escollits, sabent que hi ha un volum ideal d‟arrels humides que milloren la resposta del cultiu. Un aspecte innovador, és que els estudis fan referència al percentatge de VSH respecte al "Volum Potencial d‟Exploració Radicular" (VPER). Per a l‟olivera 1) Es determina el comportament productiu, vegetatiu i de qualitat de l‟oli per a dues estratègies de reg (total i deficitari), amb cinc percentatges de VSH (12%, 24%, 35%, 47% i 59), i 2) Es comparen aquests comportaments entre les estratègies de reg i entre el VSH d‟una estratègia respecte a l‟altra. Els resultats obtinguts a l‟experiència mostren una dependència creixent de la producció d‟oliva respecte al nivell o percentatge de sòl humit generat sota la copa de l‟arbre, manifestant-se més aquest comportament en condicions d‟escassetat d‟aigua (reg deficitari controlat RDC), i a mida que avança el període experimental. En mullar un 59% del volum de sòl potencialment explorat per les arrels (VPER) és quan s‟assoleix la producció més alta d‟oliva i d‟oli per ha en condicions d‟aigua limitada. Aquest augment es produeix per un nombre de fruits més gran per arbre i no pel pes individual del fruit. Les estratègies de reg (total i deficitari) han generat produccions d‟oliva per ha superiors a les referents en secà. Una reducció del 20% de la dosi de reg (RDC) no ha afectat de manera significativa la collita (kg/ha), el contingut d‟oli (%) ni la seva producció (kg oli / ha). Els paràmetres de qualitat de l‟oli (polifenols, amargor i estabilitat) no han variat de manera significativa segons l‟estratègia de reg aplicada. Per a la pomera, s‟ha plantejat 1) Conèixer el comportament productiu, vegetatiu i de qualitat del fruit per a tres percentatges de VSH (22%, 44% i 66%) y 2) Definir el percentatge de VSH mínim entre els assajats que generés la millor resposta agronòmica al conreu.
El seguiment durant tres anys de l‟experiència no ha permès observar un comportament productiu diferenciat del cultiu (kg/arbre) en funció del percentatge de VSH. No obstant, hi ha una producció total i comercial (Φ > 70 mm) superior de poma quan el percentatge de sòl humit és del 44%, però sense diferència significativa respecte als altres percentatges. Aquesta producció té més relació amb el pes mitjà del fruit que amb el nombre de fruits per arbre. Els aspectes qualitatius
de la fruita (duresa, sucres i acidesa) no han mostrat diferències significatives en variar el percentatge del sòl humit (VSH). En avellaner s‟ha pretès 1) Esbrinar la resposta productiva, vegetativa i de qualitat del fruit per a quatre percentatges de VSH (6%, 15%, 33% i 70%) i 2) Identificar el percentatge de VSH mínim que ocasiona el millor comportament agronòmic del cultiu. Els resultats obtinguts mostren que el percentatge més baix de sòl humit (6%), molt habitual a les explotacions comercials del camp de Tarragona, és el que ha produït, significativament, una collita d‟avellana en closca més baixa. En canvi, amb un 33% de VSH és quan s‟assoleix a la producció més alta, encara que no és significativament diferent dels tractaments de VSH-15% i VSH-70%. També, durant dos dels tres anys de l‟estudi, el pes mitjà del gra (g) va ser superior de forma significativa en humitejar un 33% del VPER. Els efectes d‟un període inicial d‟adaptació radicular del cultiu a les noves condicions dels experiments i d‟una diferent freqüència en l‟aplicació del reg, per als diversos percentatges de VSH experimentats, podrien haver estat la causa de les respostes poc diferenciades en varis dels paràmetres analitzats.
La tesis doctoral, cuyo compendio resumido ahora se presenta, mantiene como hilo conductor subyacente la aplicación eficiente del agua de riego a nivel de parcela agrícola. El manejo del agua en la agricultura, sector productivo que usa el mayor porcentaje de este elemento (77.5%), es fundamental si se quiere incidir favorablemente sobre el consumo y la actual política hidráulica, más orientada a un incremento de la oferta que a un control de la demanda. En este sentido, la elección de un sistema de riego eficiente, como es el de microirrigación, con un diseño adecuado a las circunstancias intrínsecas de la parcela, serán decisivos en este sentido. Sin embargo, el estudio de todos aquellos aspectos que optimicen el funcionamiento de la instalación, desde el punto de vista aplicativo, requiere, previamente, conocer como se mueve y distribuye el agua en el perfil del suelo. La evaluación de la forma y tamaño del volumen de suelo húmedo (VSH) no es un aspecto menor ni fácil de llevar acabo, siendo la mayoría de las veces soslayado durante el proceso de diseño. Las contadas recomendaciones existentes al respecto, casi siempre, se refieren a superficie de suelo mojado y en muy raras ocasiones a VSH, a pesar de que la exploración radicular en los cultivos, habitualmente, adopta formas volumétricas y en menor frecuencia formas superficiales. Tomando en consideración estos antecedentes y ante la falta de información existente sobre las características del VSH y su posible influencia sobre el comportamiento de los cultivos, se plantean dos objetivos generales: 1) Diseñar un Equipo Medidor del Volumen de Suelo Húmedo (EMVSH), verificado en laboratorio y campo y 2) Determinar la influencia del porcentaje de VSH en tres especies arbóreas como son el olivo (Olea europaea L.), el manzano (Malus domestica BORK) y el avellano (Corylus avellana L.). Respecto al primer objetivo, el fundamento del diseño del EMVSH se basa en el concepto según el cual el agua posee moléculas con una desigual distribución de la carga eléctrica y un comportamiento polar que facilita el paso de la corriente eléctrica. En base a ello, cuando aumenta el contenido hídrico de un medio poroso, como el suelo, mejora el flujo de corriente a través del mismo. Por el contrario, cuando disminuye ese contenido hídrico disminuye el flujo de corriente y aumenta la resistividad (ρ). Asimismo se considera la clara influencia de la temperatura del suelo sobre el valor de la resistividad, de tal manera que la disminución de aquella ocasiona el incremento de la resistividad eléctrica y viceversa. Fruto de diversos ensayos en laboratorio aplicando las metodologías de prospección geoeléctricas y más concretamente la de Wenner, basada en la evaluación directa de la resistividad eléctrica (ρ), se llevó a cabo el diseño del EMVSH. La fiabilidad del EMVSH, respecto a su capacidad para definir la forma y tamaño del VSH, se ha verificado a nivel de laboratorio en condiciones simuladas y en campo mediante seis pruebas en suelos caracterizados taxonómicamente en los términos municipales de Flix y Bovera (Tarragona y Lleida). En las pruebas de campo, estadísticamente diseñadas, se establecieron seis tipos de irrigadores con tiempos variables de aplicación.
Las secciones verticales generadas en esas pruebas indican la existencia de tres fases en el desarrollo del VSH: 1) Fase de avance con predominio de desplazamiento vertical 2) Fase de llenado y 3) Fase de saturación con predominio de desarrollo horizontal. Se ha observado buena correlación entre el volumen de agua total aplicada por cada irrigador respecto a su radio mojado a 30 cm de profundidad y al VSH que se genera. También se observa correlación entre el área mojada (m2) a 30 cm y VSH (m3) que se genera, si se consideran los valores medios alcanzados por los distintos irrigadores para los diferentes suelos del área estudiada. La relación entre el radio mojado a 30 cm y la profundidad máxima alcanzada por el VSH presenta valores próximos a 0.8 (formas hemiesféricas) en los irrigadores de bajo caudal (2.5 - 5 l/h) y valores superiores a 1 (formas elipsoidales) en los irrigadores de mayor caudal (8, 24 y 35 l/h). En relación al segundo objetivo se ha estudiado el VSH necesario y suficiente que, evaluado mediante el EMVSH, proporcionara el mejor comportamiento agronómico de los tres cultivos elegidos, sabiendo que hay un volumen ideal de raíces húmedas que mejoran la respuesta del cultivo. Un aspecto innovador es que los estudios hacen referencia a porcentaje de VSH respecto al Volumen Potencial de Exploración Radicular‟ (VPER). Para el olivo 1) Se determina el comportamiento productivo, vegetativo y de calidad del aceite para dos estrategias de riego (total y deficitario) con cinco porcentajes de VSH (12%, 24%, 35%, 47% y 59%) y 2) Se comparan esos comportamientos entre las estrategias de riego y entre VSH de una estrategia respecto a la otra. Los resultados alcanzados en la experiencia indican una creciente dependencia de la producción de aceituna respecto al nivel o porcentaje de suelo húmedo generado bajo la copa del árbol, siendo más manifiesto este comportamiento en condiciones de escasez de agua (riego deficitario controlado, RDC) y a medida que avanza el período experimental. Al mojar un 59% del volumen de suelo potencialmente explorado por las raíces (VPER) es cuando se alcanza la mayor producción de aceituna y de aceite por ha en condiciones de agua limitada. Ese aumento ha sido ocasionado por un mayor número de frutos por árbol y no por el peso individual del fruto. Las estrategias de riego (total y deficitario) han generado producciones de aceituna por ha superiores a las referentes de secano. Una reducción del 20% de la dosis de riego (RDC) no ha afectado de manera significativa la cosecha (kg/ha), el contenido de aceite (%) ni su producción (kg aceite / ha). Los parámetros de calidad del aceite (polifenoles, amargor y estabilidad) no han variado de manera significativa por la estrategia de riego aplicada. Para el manzano se ha planteado 1) Conocer el comportamiento productivo, vegetativo y de calidad del fruto para tres porcentajes de VSH (22%, 44% y 66%) y 2) Definir aquel porcentaje de VSH mínimo entre los ensayados que generasen la mejor respuesta agronómica del cultivo.
El seguimiento durante tres años de la experiencia no ha permitido observar un comportamiento productivo diferenciado del cultivo (kg/árbol) en función del porcentaje de
VSH. Sin embargo, hay una mayor producción total y comercial (Ф > 70 mm) de manzana cuando el porcentaje de suelo húmedo es del 44%, pero sin diferencia significativa respecto a los otros porcentajes. Esa producción tiene más relación con el peso medio del fruto que con el número de frutos por árbol. Los aspectos cualitativos del fruto (dureza, azucares y acidez) no han manifestado diferencias significativas al variar el porcentaje de suelo húmedo (VSH). En avellano se ha pretendido 1) Averiguar la respuesta productiva, vegetativa y de calidad del fruto para cuatro porcentajes de VSH (6%, 15%, 33% y 70%) y 2) Identificar el porcentaje de VSH mínimo que ocasiona el mejor comportamiento agronómico del cultivo. Los resultados alcanzados indican que el porcentaje más bajo de suelo húmedo (6%), muy habitual en las explotaciones comerciales del campo de Tarragona, es el que ha producido, significativamente, menor cosecha en cáscara. En cambio, con un 33% de VSH es cuando se ha alcanzado la mayor producción, aunque no ha diferido de forma significativa de los tratamientos VSH-15% y VSH-70%. Asimismo, durante dos de los tres años ensayados, el peso medio del grano (g) fue superior de forma significativa al humedecer un 33% del VPER. Los efectos de un período inicial de adaptación radicular y de una distinta frecuencia en la aplicación del riego, para los diversos porcentajes de VSH ensayados, tal vez han ocasionado respuestas poco diferenciadas en varios de los parámetros analizados.
The Doctoral Thesis, which summarised compendium is presented here, keeps as underlying leitmotiv the efficient management of the water irrigation in the orchard. The management of water in agriculture, being the productive sector using the highest water percentage (77.5%), is fundamental if we want to influence favorably about the consumption and the current hydraulic politics, more focused on increasing the offer than on the control of the demand. The election of an efficient irrigation system, as the micro-irrigation, with a correct design considering the specific characteristics of the orchard, will be decisive. However, the study of all those aspects which permit optimising the functioning of the installation, with regard to the water application, requires a previous knowledge about how the water runs and spreads in the soil profile. The evaluation of the shape and size of the wet volume of the soil (WVS) is not a minor aspect, neither easy to achieve, and which in most cases is not considered during the process of design. The few recommendations found on this aspect refer nearly always to the wet surface and only rarely they refer to WVS, although the exploration of the crop roots usually adopt volumetric forms. Considering these antecedents and the absence of information about the characteristics of the WVS and its possible influence with regard to crop behaviour, two general objectives have been raised: 1) To design a Measure Equipment of the Wet Volume of the Soil (MEWVS), calibrated in laboratory and orchard and 2) To determine the influence of the percentage of the WVS in three fruit crops as olive (Olea europaea L.), apple tree (Malus domestica L.) and hazelnut tree (Corylus avellana L.). Referring to the first objective, the design of the MEWVS is based on the concept that the water has molecules with unequal distribution of the electric charge and a polar behaviour that permits the circulation of the the electric flux. Therefore, when the water content of a porous medium is increased, like the soil, the electric flux within it improves. On the contrary, when this water content is reduced, the electric flux decreases and the resistivity (ρ) increases. In the same way, the influence of the soil‟s temperature about the resistivity is considered. The temperature drop occasions the raise of the resistivity and vice versa. Several laboratory proves were realized applying the prospecting geoelectric methodologies, like WENNER, based on the direct evaluation of the electric resistivity (ρ), and the MEWVS design was done. The viability of the MEWVS, concerning its capacity to define the form and size of the WVS, has been proved in the laboratory in simulated conditions and in the orchard by means of six field tests in taxonomically defined soils in Flix and Bovera areas (Tarragona and Lleida). In the field tests, statistical designed, six irrigator types were applied with variable irrigation times.
The vertical sections generated in these field tests show three phases in the development of the WVS: 1) Advance Phase with predominance of the vertical movement of the water 2) Filling Phase and 3) Saturation Phase with predominance of the horizontal movement. Good correlation was observed between the total volume of water applied for every irrigator with regard to its wet radius at 30 cm deep and to the WVS generated. Also, correlation is observed between the wet area (m2) at 30 cm deep and WVS (m3) generated, considering the average values reached by the different irrigators for the different soils of the studied area. In the irrigators of low flow (2.5 - 5 l / h) the relation between the wet radius at 30 cm and the maxim deepness of the WVS present values near to 0.8 (hemiesferic forms), while in the bigger flow irrigators (8,24 and 35 l/h) relations above 1 (elliptic forms) were obtained. With regard to the second objective, the necessary and sufficient WVS has been studied which, evaluated through the MEWVS, generates the best agronomic comportment of the three elected crops, knowing than there is an ideal volume of wet roots that improve crop comportment. A new aspect is that studies refer to the percentage of the WVS related to the "Potential Volume of Root Exploration" (PVER). For the olive crop 1) Crop and vegetative behaviour are determined, also the oil quality for two irrigation strategies (total and limited irrigation) with five percentages of WVS (12%, 24%, 35%, 47% and 59%) and 2). These comportments are compared with the different irrigation strategies and with the WVS of the different strategies considered. The results obtained in the experiment shows that the olive harvest depends increasingly to the level or percentage of WVS generated under the tree crown, being more pronounced this comportment in drought conditions (limited irrigation) and according the experimental period is advancing. When 59% of the soil volume potencially explored by the rootsystem (PVER) is wetted, the highest olive production is achieved and most olive oil per hectare in limited water conditions. This increase has been generated by a higher number of fruits per tree and not by the individual fruit weight. The irrigation strategies (total and limited irrigation) have generated bigger olive productions per hectare than those produces in dry farming conditions. A dose reduction of 20% in limited irrigation has not affected the olive harvest (kg/ha) in a significant way, nor the oil content (%) or its production (kg oil / ha). The oil quality parameters (poliphenols, bitterness and stability) have not varied significantly due to the applied irrigation strategy. In the apple tree has been studied 1) - The productive and vegetative comportment and the fruit quality with regard to three percentages of WVS (22%, 44% and 66%) and 2) - The establishment of the minimum percentage of WVS among those experimented assays generating the best agronomic apple crop response.
The follow-up during three years of the experiment has not permitted to observe a differentiated productive crop comportment (kg / tree) according the WVS
percentage. However, there is a bigger total and commercial apple production (Ф>70 mm) when the percentage of wet soil is 44%, but without significant difference compared to the other percentages. This production is more related to the average fruit weight than the number of fruits per tree. The quality aspects of the fruit (hardness, sugars and acidity) have not shown significant differences when varying the WVS percentages. In the hazelnut tree have been studied 1) - The productive and vegetative response and the fruit quality applying four percentages of WVS (6%, 15%, 33% and 70%) and 2) - The minimum percentage of WVS that generates the best agronomic crop behaviour. The obtained results show that the lowest WVS percentage (6%), very common in the commercial orchards of the Tarragona area, has produced a significantly lower in-shell harvest. On the contrary, with a 33% of WVS the highest production was obtained, although it did not without differ significantly from the other percentages applied (15% and 70%). Also, during two of the three experimented years, the average weight of the kernel (g) was significantly higher when 33% of the PVER was wetted. The effect of an initial period of the roots‟ adaptation to the new conditions of the experiment and the different frequency in the irrigation application, for several percentages of WVS, could be the raison for not found significantly differences among analyzed parameters.

Les nématodes gastrointestinaux (NGIs) représentent une contrainte majeure en élevage des ruminants. Jusqu’à présent, la maîtrise de ces parasitoses a reposé essentiellement sur l’emploi répété de traitements anthelminthiques (AH) de synthèse. Cependant, le développement constant de résistances aux AH dans les populations de nématodes chez les petits ruminants conduit à rechercher des méthodes alternatives ou complémentaires de lutte contre ces parasitoses. Au cours des deux dernières décennies, les données se sont accumulées montrant que certaines plantes étaient dotées de propriétés anthelminthiques, ce qui a été associé à la présence de tannins condensés (TCs) et de flavonoïdes. Ces ressources contenant des TCs, exploitées comme nutricaments, représentent donc une alternative attractive à la chimiothérapie, en combinant des effets bénéfique sur la santé et la nutrition des ruminants. Toutefois, une des difficultés à résoudre, pour un usage pertinent de ces nutricaments, est de comprendre l’origine de la variabilité des résultats observés dans l’activité AH. A côté de facteurs quantitatifs, la qualité (la structure) des TC semble également jouer un rôle dans les propriétés antiparasitaires mais ce facteur demeure peu exploré. En utilisant Haemonchus contortus comme modèle expérimental de nématode et le sainfoin (Onobrychis viciifolia) comme modèle de plantes contenant des tannins, l’objectif général de cette thèse a été de mieux comprendre les relations structure/activité des TCs. Les objectifs spécifiques des diverses études menées ont été 1) d’ examiner in vitro (par la méthode LEIA) l’activité AH de 36 fractions purifiées de TCs présentant une large diversité de caractéristiques structurelles [ex: la taille (mDP), les proportions prodelphinidols /procyanidols (PD/PC) et trans/cis ], et 2) le rôle possible d’interactions entre tannins et flavonoïdes, 3) d’ évaluer et comparer in vivo chez des agneaux, les conséquences sur les populations de vers et sur la résilience de l’hôte de la distribution de 2 ressources contenant des TCs de qualité contrastée pour les valeurs PD/PC [fort PD/PC, sainfoin (O. viciifolia); bas PD/PC, pellicules de noisettes (Corylus avellana)], 4) d’ examiner si les résultats varient en fonction de l’espèce et de la localisation des parasites (abomasum, H. contortus vs intestin grêle, Trichostrongylus colubriformis), 5) d’évaluer les concentrations, la qualité et la bio-disponibilité des TCs le long du tube digestif chez les ovins. Les résultats acquis ont montré: 1) des relations in vitro entre certaines caractéristiques des TCs et l’activité AH : un rapport élevé PD/PC pour les 2 espèces de nématodes auquel s’ajoute un rôle de la taille des tanins (mDP) pour H. contortus sont les facteurs identifiés. De manière générale, H. contortus s’est avéré plus sensible (valeurs EC50 plus faibles) aux effets des diverses ressources que T. colubriformis. Des synergies d’effets AH ont été observés entre tannins et flavonoides (quercétine et lutéoline), tout particulièrement dans le cas de TCs avec un faible rapport PD/PC. Dans l’étude in vivo, les agneaux consommant du sainfoin ont montré des effets AHs et une amélioration de la résilience de l’hôte alors que les effets de la noisette ont été beaucoup plus discrets. Les analyses menées sur les contenus des divers organes digestifs et les fèces, pour les deux types de ressources ont montré de fortes réductions de TCs détectés par rapport aux teneurs initiales dans la ration alors que les caractéristiques de structure étaient globalement préservées au long du tube digestif. En conclusion, le rôle de la qualité (structure) des TCs dans l’activité AH a été confirmé à la fois par les études in vitro et in vivo. Ces résultats suggèrent l’importance de prendre en compte ces facteurs dans la recherche de ressources pouvant être exploitées comme futurs nutricaments chez les ruminants.

The black truffle (Tuber melanosporum Vitt.) industry in Australia is relatively new and has enormous potential but some truffières (truffle farms) fail to meet anticipated harvest projections. Inappropriate soil conditions and climate, and the management of such factors are suggested as the primary reasons for inadequate yield. In addition, requirements for ascocarp initiation and development and the role of the host plant in such processes are unknown. This study examines interactions between European hazel (Corylus avellana L.) and the ectomycorrhizal (ECM) black truffle symbiont in a commercial truffière (Hazel Hill) in south-western Australia. Specific studies were initiated to examine the interactions of host physiology, mycorrhizal infection and the interaction with abiotic factors. The study related specific physiological processes of the host plant to the known life cycle of the black truffle to determine the role of the host plant in ascocarp production, if any. The work also examined the effect of silvicultural treatments intended to increase truffle production. A review of existing literature was undertaken to determine the key soil and climatic factors required for successful truffle production. Climatic conditions appeared more important than soil chemistry and structure in Western Australia, with significant seasonal variation in air and soil temperatures required plus irrigation to supplement summer rainfall. This information was used to define areas with potential for truffle production in the south-west of Western Australia: the cooler, high rainfall regions (>1000 mm annual rainfall) where there is sufficient seasonal variation in soil temperature and availability of adequate quantities of quality water for irrigation. Subsurface soil acidification and salinity, as well as groundwater salinity, are constraining factors. Lime amendment is necessary to create sufficiently high pH and CaCO3 levels required by the truffle fungus. A field trial was established to monitor the seasonal C dynamics of European hazel in the context of the life cycle of the black truffle. Maximum translocation of sucrose in the phloem sap coincided with the period of anticipated rapid growth of the truffle ascocarp implicating the use of current photosynthate in C nutrition of the ascocarp. Sampling of non-structural carbohydrates (NC) of above and belowground plant material indicated maximum storage of C in the host coincides with maturation of the ascocarp. These observations provide evidence of a synchronous growth habit of the plant host and the ascocarp. The C allocation patterns of European hazel in response to liming a loamy soil, taken from near the Hazel Hill truffière, and inoculation with ECM fungi (T. melanosporum, Hebeloma sp. and Scleroderma sp.) were examined in a glasshouse pot trial. Liming increased biomass allocation to the shoot and induced deficiencies of phosphorus and manganese. Colonisation by ECM fungi significantly increased net photosynthesis, indicating the sink strength of these fungi, but there was no relationship between the level of mycorrhizal infection and fine root NC. The maximum rate (40 g lime kg-1 soil) reduced infection by Hebeloma and Scleroderma and had no impact on T. melanosporum. Further, infection rates of T. melanosporum did not increase in response to lime suggesting lime is not necessary for ECM development in this soil type. Fertiliser is widely used in commercial truffières in Australia but the consequences for truffle production are unknown. In a field trial, the growth and physiological response of European hazel to forms of phosphorus (34 and 68 kg ha-1 apatite-P and 68 kg ha-1 triple super phosphate -P) and nitrogen (50 kg ha-1 of NO3- and NH4-N) were examined as well as the mycorrhizal response to fertiliser. Apatite-P increased phloem sap sucrose concentrations which was attributed to increased root biomass and associated sink capacity. Fertiliser application did not change fine root NC concentrations suggesting no increase in allocation of C to ECM structures. The highest rate of apatite-P decreased mycorrhizal infection rates of T. melanosporum and, most likely, was the result of increased infection rates of Hebeloma. In contrast to the literature relating to indigenous Australian ECM fungi, the highest rate of soluble-P did not decrease ECM infection rates in T. melanosporum. Nitrogen treatments increased foliar N content and improved gas exchange efficiency of plants, and had no adverse impact on the level of ECM infection. Fertilisation with N significantly increased soil respiration rates suggesting N limits mineralisation at this site. Some truffières manage the canopies of the host tree to ensure maximum exposure of the soil surface in order to increase soil temperatures. As there are no published data on the effect of pruning on black truffle production, a field trial was established to document the impact of canopy pruning on host physiology and soil temperature. The removal of 65% of canopy leaf area reduced phloem sap sucrose concentrations, soil respiration rate and the soluble: insoluble NC ratio of fine roots in the short term (1-3 weeks). There was no compensatory response of leaf gas exchange parameters as a result of pruning. Generally, there was no long term impact on plant physiological parameters as a result of pruning. Long term effects on soil temperature were observed as a result of pruning. Mean annual temperature and amplitude increased significantly beneath pruned trees and spring, summer and autumn soil temperatures increased as did diurnal variation as a result of pruning. Pruning did not increase winter soil temperatures and therefore would probably not impact on ascocarp maturation during this period. This research has provided insight into the C physiology of hazel associated with the black truffle and the consequences for truffle production. The results provide anecdotal evidence of direct C transfer between the host and the developing truffle, contrary to the existing paradigm that the ascocarp is saprotrophic for the majority of its growth and development. There is a need to validate this finding as there are consequences for management of commercial truffières. Liming of loam duplex soils can reduce the abundance of the most common competitor ECM fungi and should be encouraged in commercial truffières. Applying phosphorus and nitrogen to commercial truffières will improve growth rates of planted trees without adversely impacting on ECM infection by black truffle fungi, although the impact on truffle production remains unknown. It is anticipated truffle production will improve in the longer term as a result of pruning and prudent canopy management. Management options should include tree removal to reduce planting density and increase soil exposure in truffières. There is a need for longer term trials to be established to determine the C nutrition of the truffle ascocarp and to clearly define the key stages of the black truffle life cycle in Western Australia.

The great difference in the level of chloroplast variation and its geographic structure among the three main species studied here demonstrates that forest species do not form a homogeneous group. Hazel shows a genetic structure similar to many other thermophilous species and this structure, in combination with fossil evidence, indicates that the post-glacial colonisation of most of Europe originated in a refugium in western France while the Balkan and Italy were colonised from a south-eastern refugium.

In sallow and silver birch the chloroplast DNA variation and its structure does not fit with a scenario of glacial restriction to southern refugia and survival at intermediate latitudes is suggested for both species. The chloroplast DNA variation in silver birch suggests the presence of one western and one eastern European post-glacial colonisation route and limited contribution of southern populations in the colonisation of the rest of Europe. Unique haplotypes by the Ural Mountains indicates the possibility of a separate glacial origin of these populations.

The study of chloroplast DNA in species closely related to sallow and silver birch indicate that extensive hybridisation and cytoplasmic gene flow occurs within both the Salix and Betula genera in Europe. The nuclear and chloroplast phylogenies of 14 Betula species were not in complete agreement with each other or with the classical division of the Betula genus into subgenera or sections. The phylogenetic structure implies that hybridisation has played a role in the evolution of the Betula genus.

This thesis focuses on the chloroplast DNA variation in three forest tree genera: Corylus, Betula and Salix. Chloroplast PCR-RFLP is used to evaluate the post-glacial history of hazel, Corylus avellana, silver birch, Betula pendula and sallow, Salix caprea and to explore the possibility of introgression in the Salix and Betula genera. In addition, the chloroplast matK gene, its flanking regions and the nuclear ADH gene were used to study the phylogenetic relationships within the Betula genus.

The black truffle (Tuber melanosporum Vitt.) industry in Australia is relatively new and has enormous potential but some truffieres (truffle farms) fail to meet anticipated harvest projections. Inappropriate soil conditions and climate, and the management of such factors are suggested as the primary reasons for inadequate yield. In addition, requirements for ascocarp initiation and development and the role of the host plant in such processes are unknown. This study examines interactions between European hazel (Corylus avellana L.) and the ectomycorrhizal (ECM) black truffle symbiont in a commercial truffiere (Hazel Hill) in south-western Australia. Specific studies were initiated to examine the interactions of host physiology, mycorrhizal infection and the interaction with abiotic factors. The study related specific physiological processes of the host plant to the known life cycle of the black truffle to determine the role of the host plant in ascocarp production, if any. The work also examined the effect of silvicultural treatments intended to increase truffle production. A review of existing literature was undertaken to determine the key soil and climatic factors required for successful truffle production. Climatic conditions appeared more important than soil chemistry and structure in Western Australia, with significant seasonal variation in air and soil temperatures required plus irrigation to supplement summer rainfall. This information was used to define areas with potential for truffle production in the south-west of Western Australia: the cooler, high rainfall regions (>1000 mm annual rainfall) where there is sufficient seasonal variation in soil temperature and availability of adequate quantities of quality water for irrigation. Subsurface soil acidification and salinity, as well as groundwater salinity, are constraining factors. Lime amendment is necessary to create sufficiently high pH and CaCO3 levels required by the truffle fungus. A field trial was established to monitor the seasonal C dynamics of European hazel in the context of the life cycle of the black truffle. Maximum translocation of sucrose in the phloem sap coincided with the period of anticipated rapid growth of the truffle ascocarp implicating the use of current photosynthate in C nutrition of the ascocarp. Sampling of non-structural carbohydrates (NC) of above and belowground plant material indicated maximum storage of C in the host coincides with maturation of the ascocarp. These observations provide evidence of a synchronous growth habit of the plant host and the ascocarp. The C allocation patterns of European hazel in response to liming a loamy soil, taken from near the Hazel Hill truffiere, and inoculation with ECM fungi (T. melanosporum, Hebeloma sp. and Scleroderma sp.) were examined in a glasshouse pot trial. Liming increased biomass allocation to the shoot and induced deficiencies of phosphorus and manganese. Colonisation by ECM fungi significantly increased net photosynthesis, indicating the sink strength of these fungi, but there was no relationship between the level of mycorrhizal infection and fine root NC. The maximum rate (40 g lime kg-1 soil) reduced infection by Hebeloma and Scleroderma and had no impact on T. melanosporum. Further, infection rates of T. melanosporum did not increase in response to lime suggesting lime is not necessary for ECM development in this soil type. Fertiliser is widely used in commercial truffieres in Australia but the consequences for truffle production are unknown. In a field trial, the growth and physiological response of European hazel to forms of phosphorus (34 and 68 kg ha-1 apatite-P and 68 kg ha-1 triple super phosphate -P) and nitrogen (50 kg ha-1 of NO3- and NH4-N) were examined as well as the mycorrhizal response to fertiliser. Apatite-P increased phloem sap sucrose concentrations which was attributed to increased root biomass and associated sink capacity. Fertiliser application did not change fine root NC concentrations suggesting no increase in allocation of C to ECM structures. The highest rate of apatite-P decreased mycorrhizal infection rates of T. melanosporum and, most likely, was the result of increased infection rates of Hebeloma. In contrast to the literature relating to indigenous Australian ECM fungi, the highest rate of soluble-P did not decrease ECM infection rates in T. melanosporum. Nitrogen treatments increased foliar N content and improved gas exchange efficiency of plants, and had no adverse impact on the level of ECM infection. Fertilisation with N significantly increased soil respiration rates suggesting N limits mineralisation at this site. Some truffieres manage the canopies of the host tree to ensure maximum exposure of the soil surface in order to increase soil temperatures. As there are no published data on the effect of pruning on black truffle production, a field trial was established to document the impact of canopy pruning on host physiology and soil temperature. The removal of 65% of canopy leaf area reduced phloem sap sucrose concentrations, soil respiration rate and the soluble: insoluble NC ratio of fine roots in the short term (1-3 weeks). There was no compensatory response of leaf gas exchange parameters as a result of pruning. Generally, there was no long term impact on plant physiological parameters as a result of pruning. Long term effects on soil temperature were observed as a result of pruning. Mean annual temperature and amplitude increased significantly beneath pruned trees and spring, summer and autumn soil temperatures increased as did diurnal variation as a result of pruning. Pruning did not increase winter soil temperatures and therefore would probably not impact on ascocarp maturation during this period. This research has provided insight into the C physiology of hazel associated with the black truffle and the consequences for truffle production. The results provide anecdotal evidence of direct C transfer between the host and the developing truffle, contrary to the existing paradigm that the ascocarp is saprotrophic for the majority of its growth and development. There is a need to validate this finding as there are consequences for management of commercial truffieres. Liming of loam duplex soils can reduce the abundance of the most common competitor ECM fungi and should be encouraged in commercial truffieres. Applying phosphorus and nitrogen to commercial truffieres will improve growth rates of planted trees without adversely impacting on ECM infection by black truffle fungi, although the impact on truffle production remains unknown. It is anticipated truffle production will improve in the longer term as a result of pruning and prudent canopy management. Management options should include tree removal to reduce planting density and increase soil exposure in truffieres. There is a need for longer term trials to be established to determine the C nutrition of the truffle ascocarp and to clearly define the key stages of the black truffle life cycle in Western Australia.

The black truffle (Tuber melanosporum Vitt.) industry in Australia is relatively new and has enormous potential but some truffieres (truffle farms) fail to meet anticipated harvest projections. Inappropriate soil conditions and climate, and the management of such factors are suggested as the primary reasons for inadequate yield. In addition, requirements for ascocarp initiation and development and the role of the host plant in such processes are unknown. This study examines interactions between European hazel (Corylus avellana L.) and the ectomycorrhizal (ECM) black truffle symbiont in a commercial truffiere (Hazel Hill) in south-western Australia. Specific studies were initiated to examine the interactions of host physiology, mycorrhizal infection and the interaction with abiotic factors. The study related specific physiological processes of the host plant to the known life cycle of the black truffle to determine the role of the host plant in ascocarp production, if any. The work also examined the effect of silvicultural treatments intended to increase truffle production. A review of existing literature was undertaken to determine the key soil and climatic factors required for successful truffle production. Climatic conditions appeared more important than soil chemistry and structure in Western Australia, with significant seasonal variation in air and soil temperatures required plus irrigation to supplement summer rainfall. This information was used to define areas with potential for truffle production in the south-west of Western Australia: the cooler, high rainfall regions (>1000 mm annual rainfall) where there is sufficient seasonal variation in soil temperature and availability of adequate quantities of quality water for irrigation. Subsurface soil acidification and salinity, as well as groundwater salinity, are constraining factors. Lime amendment is necessary to create sufficiently high pH and CaCO3 levels required by the truffle fungus. A field trial was established to monitor the seasonal C dynamics of European hazel in the context of the life cycle of the black truffle. Maximum translocation of sucrose in the phloem sap coincided with the period of anticipated rapid growth of the truffle ascocarp implicating the use of current photosynthate in C nutrition of the ascocarp. Sampling of non-structural carbohydrates (NC) of above and belowground plant material indicated maximum storage of C in the host coincides with maturation of the ascocarp. These observations provide evidence of a synchronous growth habit of the plant host and the ascocarp. The C allocation patterns of European hazel in response to liming a loamy soil, taken from near the Hazel Hill truffiere, and inoculation with ECM fungi (T. melanosporum, Hebeloma sp. and Scleroderma sp.) were examined in a glasshouse pot trial. Liming increased biomass allocation to the shoot and induced deficiencies of phosphorus and manganese. Colonisation by ECM fungi significantly increased net photosynthesis, indicating the sink strength of these fungi, but there was no relationship between the level of mycorrhizal infection and fine root NC. The maximum rate (40 g lime kg-1 soil) reduced infection by Hebeloma and Scleroderma and had no impact on T. melanosporum. Further, infection rates of T. melanosporum did not increase in response to lime suggesting lime is not necessary for ECM development in this soil type. Fertiliser is widely used in commercial truffieres in Australia but the consequences for truffle production are unknown. In a field trial, the growth and physiological response of European hazel to forms of phosphorus (34 and 68 kg ha-1 apatite-P and 68 kg ha-1 triple super phosphate -P) and nitrogen (50 kg ha-1 of NO3- and NH4-N) were examined as well as the mycorrhizal response to fertiliser. Apatite-P increased phloem sap sucrose concentrations which was attributed to increased root biomass and associated sink capacity. Fertiliser application did not change fine root NC concentrations suggesting no increase in allocation of C to ECM structures. The highest rate of apatite-P decreased mycorrhizal infection rates of T. melanosporum and, most likely, was the result of increased infection rates of Hebeloma. In contrast to the literature relating to indigenous Australian ECM fungi, the highest rate of soluble-P did not decrease ECM infection rates in T. melanosporum. Nitrogen treatments increased foliar N content and improved gas exchange efficiency of plants, and had no adverse impact on the level of ECM infection. Fertilisation with N significantly increased soil respiration rates suggesting N limits mineralisation at this site. Some truffieres manage the canopies of the host tree to ensure maximum exposure of the soil surface in order to increase soil temperatures. As there are no published data on the effect of pruning on black truffle production, a field trial was established to document the impact of canopy pruning on host physiology and soil temperature. The removal of 65% of canopy leaf area reduced phloem sap sucrose concentrations, soil respiration rate and the soluble: insoluble NC ratio of fine roots in the short term (1-3 weeks). There was no compensatory response of leaf gas exchange parameters as a result of pruning. Generally, there was no long term impact on plant physiological parameters as a result of pruning. Long term effects on soil temperature were observed as a result of pruning. Mean annual temperature and amplitude increased significantly beneath pruned trees and spring, summer and autumn soil temperatures increased as did diurnal variation as a result of pruning. Pruning did not increase winter soil temperatures and therefore would probably not impact on ascocarp maturation during this period. This research has provided insight into the C physiology of hazel associated with the black truffle and the consequences for truffle production. The results provide anecdotal evidence of direct C transfer between the host and the developing truffle, contrary to the existing paradigm that the ascocarp is saprotrophic for the majority of its growth and development. There is a need to validate this finding as there are consequences for management of commercial truffieres. Liming of loam duplex soils can reduce the abundance of the most common competitor ECM fungi and should be encouraged in commercial truffieres. Applying phosphorus and nitrogen to commercial truffieres will improve growth rates of planted trees without adversely impacting on ECM infection by black truffle fungi, although the impact on truffle production remains unknown. It is anticipated truffle production will improve in the longer term as a result of pruning and prudent canopy management. Management options should include tree removal to reduce planting density and increase soil exposure in truffieres. There is a need for longer term trials to be established to determine the C nutrition of the truffle ascocarp and to clearly define the key stages of the black truffle life cycle in Western Australia.

Le rôle du partenaire fongique dans la protection des racines a été étudié dans le cas d'un excès cationique. Pour cela un modèle ectomycorhizien (corylus avellana/tuber melanosporum) a été expérimentalement mis en présence de divers cations, dans des conditions physiologiques et toxiques. Les voies de transport et de stockage des cations ont été définies dans les tissus racinaires et ectomycorhiziens. Pour cela, les organes ont été incube en présence de marqueurs cationiques (cérium et lanthane). Il a ainsi été démontré que les cations sont transportes radialement dans les tissus fongiques, vers la racine par les voies apoplasmiques et symplasmiques. Le mycélium exerce une action régulatrice dans la quantité et la qualité des cations qu'il transmet à son partenaire végétal. Le champignon exerce cette régulation tout au long des différents stades ponctuant la vie d'une mycorhize (stade jeune, mature et sénescent). Il a été mis en évidence expérimentalement que le mycélium truffier agit en diminuant la quantité de cations (la3+, ce3+, ca2+, cu2+, hg2+) parvenant a la racine. Pour cela, il procède à un important stockage des métaux dans ses structures. Une relation a donc été établie entre les degrés de tolérance et de résistance fongiques et ses capacités de détoxication des métaux au regard de la plante. Toutefois, ce mode d'action n'est pas général à toutes les mycorhizes, puisque l'étude expérimentale du modèle pinus pinaster/hebeloma cylindrosporum, montre que le mycélium peut également permettre le développement des végétaux en milieu toxique en favorisant sa nutrition minérale plutôt qu'en en limitant l'accès. Une étude réalisée sur le terrain révèle que le mycélium peut développer un troisième mécanisme de détoxication des métaux vis-à-vis de la plante. En effet, certains champignons possèdent une faible capacité à absorber les métaux, diminuant ainsi la quantité parvenant à la plante tout en évitant de les stocker de façon importante dans ses tissus.

Eriophyoid big bud mites are key pests of hazelnuts throughout the world, although little is known of the identity and impact of the species on New Zealand hazelnut crops. The key objectives of this study were to determine the species of mite present on New Zealand crops, explore a method of monitoring mite emergence from overwintering big buds, determine the phenology of mites in relation to tree phenology and weather, and identify the optimum timing for control measures. The presence of both Phytoptus avellanae (Nalepa 1889) (Acari: Phytoptidae) and Cecidophyopsis vermiformis (Nalepa 1889) (Acari: Eriophyidae) was confirmed, the latter species being a new record for New Zealand. Preliminary diagnostic DNA sequences were determined for both species. A sticky band technique was developed to monitor mite emergence from overwintering big buds, and mite emergence was found to occur between early and late spring. Mite emergence and movement occurred when daily temperatures were greater than 15 degrees C and when mean temperatures were greater than 9 degrees C, with mite emergence increasing with temperature. It proved difficult to relate the phenology of hazelnut to mite emergence, however, the development of new buds during mite emergence was a crucial factor in the infestation of new buds. An accumulated heat sum model (DD), started at Julian date 152 and using a lower threshold temperature of 6 degrees C, predicted the onset of emergence on two cultivars and at two sites as occurring at approximately 172 DD. A regression model based on leaf number, bud height, bud width, DD and Julian date provided a more satisfactory prediction of percent accumulated mite emergence. It is recommended both peak mite emergence and the appearance of hazelnut buds should be used to optimise the time to apply control measures. Therefore, a control should be applied before buds measure 0.5 x 0.5 mm (width x height), are enclosed within the axil, and have a rounded tip, or, when 50% accumulated mite emergence has occurred, which ever occurs first. A preliminary field experiment tested the application of sulphur (40 g/10 litres of 800 g/kg No Fungus Super Sulphur) at 2, 50 and 80% accumulated mite emergence. The greatest reduction in mite numbers was achieved with an application at approximately 50% emergence. Considerable variation in mite emergence occurred between years, therefore optimum timing of controls would need to be determined by monitoring mites, new buds and weather conditions each year. Field collection of mites also identified the presence of Typhlodromus doreenae Schicha (Acari: Phytoseiidae) which would warrant further study for inclusion in an integrated mite control programme.

Le principali anomalie evidenziate nelle nocciole avariate riguardano la presenza di macchie necrotiche, imbrunimenti interni rilevati inseguito al taglio dei frutti e la presenza di marciumi parziali o totali su di essi con conseguente riduzione del prodotto disponibile sul mercato e ingenti perdite economiche. Sulla base di quanto premesso, lo scopo principale di questa tesi è stato quello di identificare e caratterizzare l'agente causale/i dei difetti del nocciolo e di definire un protocollo di gestione del problema, secondo i principi IPM. È stata quantificata l'incidenza dei generi fungini isolati da nocciole provenienti da diverse aree geografiche (Caucaso e Turchia), raccolte in diversi anni e in diverse fasi di crescita della coltura. Diaporthe è stato identificato come il principale genere fungino associato ai difetti della nocciola, e la caratterizzazione molecolare ha confermato il ruolo predominante della specie D. eres. Sono state studiate le caratteristiche ecologiche di questo fungo e l'efficacia in vitro di fungicidi chimici e biologici per controllarne la crescita miceliale, lo sviluppo di picnidi e la formazione di cirri. I risultati ottenuti costituiscono una base per definire linee guida per la corretta gestione della coltura al fine di prevenire la comparsa del patogeno identificato e delle difettosità nelle nocciole
Defects on hazelnuts are responsible for a significant reduction in the availability of high-quality hazelnuts with profound economic impacts. A reduction in the occurrence of defects, based on the identification of causal agents and on their control, is critical to improve the quality of raw nut products and reduce yield losses. Based on this background, the main aim of this thesis was to identify and characterize the causal agent/s of kernel defects in hazelnuts and to define a management protocol, according to IPM principles. Defects affecting hazelnuts are cause of brown spots on the kernel surface and darkening/browning inside the kernel, visible after nuts are half-cut. The incidence of fungal genera in hazelnuts coming from different geographical areas (Caucasus and Turkey), collected in different years at different crop growth stages, was quantified. Diaporthe was identified as the main genus involved in hazelnut defects, and the molecular characterization confirmed the predominant role of D. eres. Its ecological needs were investigated, and the in vitro efficacy of chemical and biological fungicide were screened to control D. eres growth, pycnidial conidiomata development and cirrhi occurrence. This would be an essential tool for a sustainable crop protection approach in this economically important crop

Le principali anomalie evidenziate nelle nocciole avariate riguardano la presenza di macchie necrotiche, imbrunimenti interni rilevati inseguito al taglio dei frutti e la presenza di marciumi parziali o totali su di essi con conseguente riduzione del prodotto disponibile sul mercato e ingenti perdite economiche. Sulla base di quanto premesso, lo scopo principale di questa tesi è stato quello di identificare e caratterizzare l'agente causale/i dei difetti del nocciolo e di definire un protocollo di gestione del problema, secondo i principi IPM. È stata quantificata l'incidenza dei generi fungini isolati da nocciole provenienti da diverse aree geografiche (Caucaso e Turchia), raccolte in diversi anni e in diverse fasi di crescita della coltura. Diaporthe è stato identificato come il principale genere fungino associato ai difetti della nocciola, e la caratterizzazione molecolare ha confermato il ruolo predominante della specie D. eres. Sono state studiate le caratteristiche ecologiche di questo fungo e l'efficacia in vitro di fungicidi chimici e biologici per controllarne la crescita miceliale, lo sviluppo di picnidi e la formazione di cirri. I risultati ottenuti costituiscono una base per definire linee guida per la corretta gestione della coltura al fine di prevenire la comparsa del patogeno identificato e delle difettosità nelle nocciole
Defects on hazelnuts are responsible for a significant reduction in the availability of high-quality hazelnuts with profound economic impacts. A reduction in the occurrence of defects, based on the identification of causal agents and on their control, is critical to improve the quality of raw nut products and reduce yield losses. Based on this background, the main aim of this thesis was to identify and characterize the causal agent/s of kernel defects in hazelnuts and to define a management protocol, according to IPM principles. Defects affecting hazelnuts are cause of brown spots on the kernel surface and darkening/browning inside the kernel, visible after nuts are half-cut. The incidence of fungal genera in hazelnuts coming from different geographical areas (Caucasus and Turkey), collected in different years at different crop growth stages, was quantified. Diaporthe was identified as the main genus involved in hazelnut defects, and the molecular characterization confirmed the predominant role of D. eres. Its ecological needs were investigated, and the in vitro efficacy of chemical and biological fungicide were screened to control D. eres growth, pycnidial conidiomata development and cirrhi occurrence. This would be an essential tool for a sustainable crop protection approach in this economically important crop

In questo lavoro di tesi è stata valutata l’influenza della tostatura a diverse condizioni di tempo e temperatura sulle principali caratteristiche qualitative di nocciole polacche (Coryllus avellana L.) di varietà Kataloński. In particolare, le prove di tostatura sono state condotte a due differenti temperature, 130 e 160 °C, ognuna delle quali applicata rispettivamente per tre diversi tempi: 40, 50, 60 e 20, 25, 30 minuti. Al fine di definire le condizioni ottimali di tostatura, i campioni ottenuti sono stati sottoposti ad analisi colorimetrica (L*,a*,b*), dell’attività dell’acqua e del contenuto in acqua (%). Inoltre, per ottenere un quadro completo della qualità delle diverse nocciole tostate, è stato valutato anche il loro contenuto in composti bioattivi per mezzo della determinazione del contenuto in fenoli totali (metodo del Folin-Ciocalteu), dei singoli composti fenolici (HPLC-MS) e dell’attività antiossidante (metodo dell’ABTS·+). In seguito ad estrazione della frazione lipidica, è stato determinato anche il contenuto in tocoferoli (HPLC-FLD) e lo stato ossidativo delle nocciole tostate per mezzo dell’analisi del numero di perossidi. Infine è stato studiato anche l’effetto della tostatura sullo sviluppo di composti volatili (GC-MS), caratteristici dell’aroma tipico delle nocciole tostate. Questo studio rappresenta un importante screening di valutazione delle nocciole tostate a diversi tempi e temperature e mostra come la temperatura sia un parametro molto importante, con una forte influenza sulle caratteristiche compositive e sensoriali del prodotto finito. Sulla varietà Kataloński non sono presenti lavori in letteratura, questo studio quindi rappresenta una novità per quanto riguarda questa specifica varietà. Le numerose analisi svolte, poi, consentono un ampio quadro dei fenomeni che si verificano durante la tostatura.

Hazel (Corylus avellana L.) is a common feature of meadows and pastures where it can grow in large populations and become very old. Is it possible to use the size of hazel stools for age determination and is it possible to use the size distribution of a population to provide information about how the land has been used? Hazel populations on ground where the lake-water level had been lowered, has been studied to validate an already developed growth model of hazel clones. Different hazel populations, on wooded meadows affected by mowing or grazing or overgrown meadows, were studied to evaluate the method utilizing hazel as land use indicator. The growth model was used to compare the size distributions of hazel populations with historical periods, which has been important for changes in agriculture or demography. The results show that the current growth model needs to be refined, but the method itself with a growth model based on the circumference of hazel bushes seems feasible. Additional studies about the influence of, for example, soils of different fertility are needed. The results also show that the size distribution in a population depends on how much meadows have been affected by mowing or grazing and that areas with similar land use have similar size distribution. Finally, some examples are reported about how a growth model can be used to compare historical periods of changes in agriculture, for example reduced livestock, with variations of the size distribution in a hazel population.

Haselnüsse werden als Lebensmittel im Hinblick auf eine ausgewogene und gesunde Ernährung immer beliebter. Sie sind reich an ungesättigten Fettsäuren und Proteinen, enthalten Vitamine, Polyphenole, Antioxidantien und Mineralstoffe sowie weitere bioaktive Substanzen. Regelmäßiger Nusskonsum soll unter anderem koronaren Herzerkrankungen, Gallensteinen und Diabetes (bei Frauen) vorbeugen (Alasalvar und Shahidi, 2009; Ros, 2010). In den Jahren 2006 bis 2014 stieg der Pro-Kopf-Konsum an Nüssen von 3,8 auf 4,6 kg pro Jahr an. Laut der Bundesanstalt für Landwirtschaft und Ernährung (BLE) wurden im Wirtschaftsjahr 2014 (Juli 2014 bis Juni 2015) 345.200 t Nüsse nach Deutschland importiert. Mit 105.000 t wird die Erdnuss in Deutschland am häufigsten verzehrt, doch auch die Haselnuss stellt mit 53.600 t ein sehr beliebtes Nahrungsmittel dar. (BLE, 2015; Ros, 2010) Haselnüsse werden roh oder geröstet, pur oder als Zutat für andere Lebensmittel und Backwaren, verzehrt. Durch die Röstung wird unter anderem die Haltbarkeit durch die Abtötung von Mikroorganismen und der Enzyminaktivierung verlängert (Durmaz und Gökmen, 2010), aber auch Farb- und Aromastoffe gebildet, welche das Aussehen und den Geschmack der Nüsse verbessern. Hierbei spielen vor allem die Maillard-Reaktion, welche eine Vielzahl von Einzelreaktionen von reduzierenden Zuckern mit freien oder proteingebundenen Aminosäureseitenketten, bevorzugt die des Lysins, beschreibt, sowie die Lipierung, welche analog die Reaktion von Protein- bzw. Lysinseitenketten mit Sekundärprodukten der Lipidperoxidation bezeichnet, eine Rolle. Die gewählten Röstbedingungen (Temperatur und Dauer) sind ausschlaggebend für die Bildung von Maillard- und Lipierungsprodukten in Nüssen. Es stellt sich die Frage, in welchem Maße diese Produkte bereits in den rohen Nüssen vorhanden sind und wie sich ihre Gehalte während der Erhitzung in Abhängigkeit von Rösttemperatur und -dauer verändern. Hierfür wurden sechs Maillard-Produkte und drei Lipierungsprodukte ausgewählt und deren Gehalte während der Haselnussröstung verfolgt. Lipierungsprodukte wurden im Rahmen der Arbeit erstmals in Haselnüssen untersucht. Aufgrund des hohen Fettgehalts von Haselnüssen wurden mögliche Einflussfaktoren auf die Bildung von Lipierungsprodukten genauer untersucht und zwischen verschiedenen Nusssorten verglichen. Im Anschluss erfolgte eine Abschätzung der Beeinflussung der Lipierungsproduktbildung in Abhängigkeit der Nusszusammensetzung. Hierbei spielen vor allem Faktoren wie der Fett- und Proteingehalt sowie die Fettsäure- oder Aminosäurezusammensetzung eine Rolle. Ein alternatives Verfahren zur Haltbarmachung, was bereits bei Fleischprodukten und Fruchtsäften Anwendung findet, stellt die Hochdruckbehandlung dar (Henle und Schwarzenbolz, 2015). Bisher wurde dieses Verfahren noch nicht auf Haselnüsse oder Nüsse im Allgemeinen angewandt und es gibt keinerlei Untersuchungen zu strukturellen Veränderungen der Proteine bzw. zu den Auswirkungen auf die Maillard- und Lipierungsproduktbildung im Zuge einer anschließenden Röstung. Aufgrund langer Transportwege und einer möglichweise verbesserten Lagerstabilität roher Nüsse wäre eine Hochdruckbehandlung auch für Haselnüsse relevant. Im Rahmen dieser Arbeit wurden erstmals Untersuchungen zum Einfluss einer Hochdruckbehandlung auf die Bildung von Maillard- und Lipierungsprodukten in Haselnüssen durchgeführt. Die Haselnussallergie stellt, mit etwa 2,2 % Betroffenen in Europa (EFSA, 2014), eine der Hauptnahrungsmittelallergien dar. Schon 10 mg einer rohen Haselnuss können ausreichen, um eine allergische Reaktion hervorzurufen (Worm et al., 2009). Innerhalb Europas lassen sich regionale Unterschiede hinsichtlich des auslösenden Allergens sowie der Schwere der Symptome feststellen. Im Norden Europas stellt das Birkenpollenhomologon Cor a 1 das Hauptallergen dar, welches oft mit einer Kreuzallergie zu anderen birkenpollenassoziierten Lebensmitteln einhergeht und meist eine milde Symptomatik, wie das orale Allergiesyndrom auslöst. Im Südeuropäischen Raum hingegen sind Patienten vor allem gegen das Lipid-Transfer-Protein Cor a 8 sensibilisiert, welches schwere Symptome bis hin zur Anaphylaxie auslösen kann. (Pastorello et al., 2002; Datema et al., 2015) Die Erhitzung und Hochdruckbehandlung von Haselnüssen kann die Allergenität beeinflussen. Im Rahmen dieser beiden Verfahren kann es zu Proteinmodifikationen und zu strukturellen Veränderungen der Proteine kommen, wobei Auf- und Umfaltungsreaktionen Epitope der Allergene maskieren oder freilegen können. Die Allergenität kann somit verringert oder verstärkt werden. In dieser Arbeit wurden die Auswirkungen einer Röstung mit und ohne vorhergehender Hochdruckbehandlung auf das Haselnussallergen Cor a 8 analysiert. Hierbei wurde das allergene Potential anhand des IgE-Bindungsvermögens von Humanseren mittels Western Blots abgeschätzt. Das Ziel dieser Arbeit war es Proteinmodifikationen, die im Rahmen der Röstung und Haltbarmachung von Haselnüssen entstehen, näher zu charakterisieren und deren Einfluss auf das allergene Potential zu beschreiben.

This thesis was expressly elaborated to fulfil the requirements application to the Doctoral Degree in Agricultural Production Chains - From Fork to Farm by the University of Trás-os Montes e Alto Douro
Climate change affects directly several economic sectors, namely agriculture, forestry, energy consumptions, tourism among others. In agriculture, the climate change has a huge impact on crop growth and yield. This takes great importance in perennial fruit crops due to their higher sensitivity to environmental conditions, particularly on floral differentiation, blossom, pollination, fruit setting and growth stages. Temperate fruit treesrequire some chilling during the development, however climate change is making climates warmer, which significantly influence the crops growth and yield. Furthermore, the average global temperature will move plant species to new areas with more favourable climate conditions. These difficulties will be transversal to all perennial fruit species being hazelnut (Corylus avellana L.) one of them, especially those growing in Mediterranean countries. The main objective of this Doctoral Thesis is to contribute with strategies to mitigate effects of climate change and on the other hand, to enhance the quality and production of hazelnut by different approaches. To achieve these goals, an evaluation of the suitability of preharvest foliar spray treatments was performed, gaining a further insight in the agricultural management strategies by understanding the plant physiological and biochemical response, enhance hazelnut quality, environmental sustainability and economic viability for hazelnut production. In addition, regarding the massive amounts of bio-wastes, namely the hazelnut husks, the determination of the suitability of husks (hazelnut by-product) as a source of bioactive compounds was also studied. In this sense, two experiments were carried out, the first experiment consisted in spraying treatments combined with irrigation: kaolin (K, 4%); natural bioestimulant Ascophyllum nodosum (An, 0.15%); salicylic acid (SA, 0.01 %); K with irrigation (Ki); An with irrigation (Ani); SA with irrigation (SAi); control with irrigation (Ci) and control (C), during 2016 and 2017, in a hazelnut orchard with adult trees in full production using an economically important hazelnut cultivar ‘Grada de Viseu’, located in Moimenta da Beira (Northern Portugal). A positive effect of the spray treatment on ‘Grada de Viseu’ yield, physiological and biochemical responses was shown. Results showed that K and An were effective for reducing hazelnut heat and drought stresses by increasing the relative water content, net CO2 assimilation rate, water use efficiency and by reducing the leaf mass per area and electrolyte leakage. Moreover, concentration of abscisic acid, malondialdehyde, proline, lipid peroxidation and the average content of antioxidant enzymes was lower, suggesting that under K and An treatments, plants have a better physiological performance than control trees. Under K, An and SA with and without irrigation treatments, the content of total sugars decreased and the content of starch, salicylic acid, thiols and the ratio between total chlorophylls and total carotenoids increased, demonstrating that these treatments can be effective against drought. These treatments affected positively the biometric parameters, namely nut and kernel sizes, vitamin E levels, antioxidant activity and some phenolic compound contents. The sensorial attributes were not affected by the treatments, this way the application of K, AN and SA improve the hazelnut tree physiological response to the climate change, without compromising the hazelnut chemical and sensorial quality. Other experiment was carried in a hazelnut orchard with adult trees in full production in Vila Real, Portugal. Hazelnuts husks were obtained from four cultivars: ‘Butler’, ‘Grada de Viseu’, ‘Morell’ and ‘Lansing’, and the bioactive potential of hazelnut husks was determined as a function of their cultivar source and extraction solvent. A total of 11 phenolics were identified. The results showed that cultivar and extraction solvent influenced significantly the extraction yield. Methanolic husk extracts exhibited the greatest antioxidant potentials followed by water and acetone. ‘Grada de Viseu’ husks presented the highest content of individual phenolics and antioxidant activity, while the husks from the cultivar ‘Lansing’ showed the lowest levels. The valorization of hazelnuts husks gives an important contribution for the isolation and purification of bioactive molecules. In conclusion, this thesis contributed to increase knowledge of the use of promising preharvest compounds for the improvement of the hazelnut physiological and biochemical performance as well the nut quality. Nonetheless lower and non-significant differences between treatments with and without irrigation were observed revealing that K, An and SA can be used without irrigation to mitigate summer stress effects being these compounds useful strategies to mitigate climate change effects for sustainable hazelnut production
As alterações climáticas afetam fortemente vários sectores económicos da sociedade, nomeadamente a agricultura, silvicultura, consumo de energia, turismo entre outros. Na agricultura, as alterações climáticas têm um enorme impacto no desenvolvimento e produtividade das culturas, assumindo uma grande importância ao nível das espécies fruteiras perenes, devido à sua sensibilidade relativamente às condições ambientais, em particular durante a diferenciação floral, polinização, frutificação e crescimento. As espécies frutícolas, de clima temperado necessitam de frio no seu desenvolvimento e com o aumento da temperatura resultante das alterações climáticas, estas necessidade poderão ser afectadas. Para além disso, o aumento da temperatura média global, fará com que as espécies encontrem condições favoráveis ao seu crescimento em novas regiões, tornando o seu cultivo mais difícil devido ao stresse estival. Estas dificuldades serão transversais a todas as espécies de fruteiras perenes, como é o caso da aveleira (Corylus avellana L.), especialmente as que crescem nos países mediterrânicos. O principal objetivo desta Tese de Doutoramento é contribuir com estratégias para a mitigação dos efeitos das alterações climáticas e, ao mesmo tempo, aumentar a qualidade e a produção de avelã recorrendo a diversas abordagens. Essas abordagens focam-se na avaliação da aplicação de tratamentos em pré-colheita, de forma a ganhar uma visão mais aprofundada de estratégias agrícolas, nomeadamente na resposta fisiológica e bioquímica das árvores, no aumento da qualidade da avelã, na sustentabilidade ambiental e na viabilidade económica para a produção de avelãs. Para além disso, e tendo em conta as grandes quantidades de bio resíduos, e em particular os invólucros das avelãs (co-produto) desenvolveu-se um estudo com o objetivo de determinar o potencial dos invólucros como fonte de bioatividade. Neste sentido realizaramse dois ensaios experimentais, o primeiro consistiu na aplicação de compostos combinados com e sem rega: Caulino (K, 4%); bioestimulante natural à base de Ascophyllum nodosum (An, 0,15%); ácido salicílico (SA, 0,01%); K com rega (Ki); An com rega (Ani); SA com rega (SAi); controlo com rega (Ci) e controlo (C), durante 2016 e 2017, num avelanal com árvores adultas em plena produção, da cultivar economicamente importante em Portugal, ‘Grada de Viseu’, localizado em Moimenta da Beira (Norte de Portugal). Verificou-se um efeito positivo nas árvores pulverizadas com os compostos ao nível da produção, da resposta fisiológica e bioquímica. Os resultados demonstraram que K e An foram eficazes na redução dos efeitos do stresse estival, aumentando o conteúdo relativo de água, a assimilação líquida de CO2 e a eficiência de uso de água e verificando-se a redução da massa foliar por área e da fuga de eletrólitos. Além disso, a concentração de ácido abscísico, malondialdeído, prolina, peroxidação lipídica e a concentração de enzimas antioxidantes foi menor nos tratamentos, sugerindo que as árvores tratadas com K e An, tiveram um melhor desempenho fisiológico do que as árvores controlo. Nas aveleiras tratadas com K, An, e SA com e sem rega, o conteúdo total de açúcares solúveis diminuiu e o conteúdo em amido, ácido salicílico, tióis e a razão entre as clorofilas totais e os carotenoides totais aumentou, demonstrando assim que os tratamentos são eficientes contra os efeitos da seca. Os tratamentos afetaram positivamente os parâmetros biométricos avaliados, assim como o calibre da avelã e do miolo, o conteúdo em vitamina E, a atividade antioxidante e alguns compostos fenólicos. Os atributos sensoriais avaliados não foram afetados pelos tratamentos demonstrando que a aplicação de K, An e SA melhorou a resposta da árvore sob efeito dos tratamentos às alterações climática sem comprometer a qualidade química e sensorial da avelã. O segundo ensaio experimental realizou-se em Vila Real, Portugal, num avelanal com árvores adultas em plena produção. Os invólucros foram obtidos a partir de quatro cultivares: ‘Butler’, ‘Grada de Viseu’, ‘Morell’ e ‘Lansing’, foi avaliado o potencial bioativo dos invólucros em função da cultivar e do solvente de extração. Os resultados demonstraram que, quer a cultivar quer o solvente de extração influenciaram o rendimento de extração. Os invólucros extraídos com o metanol exibiram maior potencial antioxidante seguindo-se pela água e acetona. No total foram identificados 11 compostos fenólicos sendo que os invólucros da cultivar ‘Grada de Viseu’ apresentaram maiores conteúdos de compostos fenólicos individuais e de atividade antioxidante, enquanto os invólucros da cultivar ‘Lansing’ foram os que apresentaram menores níveis. O isolamento e purificação destas moléculas bioativas contribui de forma significativa para a valorização dos invólucros. Em conclusão, o trabalho realizado contribuiu para o aumento do conhecimento da utilização de compostos promissores em pré-colheita, com o intuito de aumentar o desempenho fisiológico e bioquímico, bem como a qualidade da avelã. As diferenças não significativas ou reduzidas observadas nos tratamentos com e sem rega permitem afirmar que os compostos K, An e SA podem ser usados sem o recurso à rega de forma a mitigar os efeitos do stresse estival assim como uma excelente estratégia para mitigar os efeitos das alterações climáticas.

Tese de Doutoramento em Genética Molecular Comparativa e Tecnológica
A aveleira (Corylus avellana L.), pertencente à família Betulaceae e à ordem Fagales. Esta espécie é originária da Europa e Ásia Ocidental e é cultivada há mais de 5000 anos. Ao longo dos últimos séculos, a maioria das variedades cultivadas foram selecionadas a partir de populações silvestres. Em Portugal, a aveleira encontra-se na região norte e centro. Desde a década de 90 que a sua produção está em declínio, podendo conduzir ao desaparecimento das variedades locais (“landraces”). A avaliacao da diversidade genética de espécies silvestres e populações locais revela-se de grande importância para a sua utilização e para a gestão das coleções existentes. Com o objetivo de avaliar a diversidade genética e conhecer as relações filogenéticas das aveleiras portuguesas e variedades comerciais, procedeu-se ao estudo de 58 genótipos, incluindo variedades locais, silvestres e comerciais, ao nível morfológico, molecular e bioquímico. No Capítulo 1 apresenta-se uma revisão bibliográfica sobre a origem e a domesticação da aveleira, os marcadores moleculares, os alelos de incompatibilidade (alelos S) e a composição nutricional dos frutos. A avaliação da diversidade genética ao nível do DNA cloroplastidial (cpDNA) através de microssatélites (cpSSR), encontra-se no Capítulo 2. Quatro dos dez loci estudados revelaram-se polimórficos. Encontraram-se, no total, onze haplótipos, sendo o haplótipo A o mais frequente, quer nas variedades locais quer nas comerciais. Nos genótipos silvestres detetaram-se quatro haplótipos exclusivos (H, I, J e L). Esta diversidade pode indicar o norte de Portugal como um potencial refúgio durante o último período glaciar. A diversidade genética e as relações filogenéticas, avaliadas através de marcadores inter-microssatélites (ISSRs) e Polimorfismo de Comprimento de Fragmentos Amplificados (AFLPs), apresentam-se no Capítulo 3. Foram obtidos um total de 570 marcadores, dos quais 541 (95,03%) se revelaram polimórficos. Os valores dos índices de similaridade variaram entre 0,239 para as variedades comerciais versus genótipos silvestres, e 0,143 para as variedades locais versus genótipos silvestres. As relações filogenéticas distribuíram as aveleiras por três grupos, mostrando uma clara separação dos genótipos silvestres das variedades locais e comerciais. No Capítulo 4 apresentam-se os resultados da análise com microssatélites (SSRs) nucleares, para a avaliação das relações filogenéticas. O nível de polimorfismo encontrado foi elevado, conforme o indicado pela heterozigocidade média esperada (0,74), pela heterozigocidade média observada (0,71) e pelo conteúdo de informação de polimorfismo (0,78). O dendrograma mostrou uma clara separação dos genótipos silvestres, variedades locais e variedades comerciais. Os resultados reforçam a hipótese de que os genótipos silvestres constituem um ‘hotspot’ de diversidade e fornecem pistas sobre a origem de algumas variedades locais. Os resultados obtidos para a identificação dos alelos S encontram-se no Capítulo 5. Para este estudo foram utilizadas variedades locais de aveleira que foram polinizadas no campo, com pólen de genótipos cujos alelos S são conhecidos. Três variedades locais revelaram ter o alelo S2, duas apresentaram o alelo S5, e quatro, um dos quatro alelos S3, S5, S10, S18. Uma variedade local foi compatível com todos os 17 alelos S testados, e em duas foi possível identificar dois alelos, S5 e S9. A variabilidade fenotípica e a composição nutricional dos frutos apresentam-se no Capítulo 6. Nas variedades locais observou-se o valor médio mais elevado para o peso do fruto, peso do miolo e teor em óleo, tendo as variedades comerciais apresentado os valores médios mais baixos. Os genótipos silvestres revelaram o teor médio mais alto em proteína e os valores médios mais baixos para o teor em aminoácidos essenciais. As variedades comerciais demonstraram os valores médios mais elevados para o teor em aminoácidos essenciais e para os minerais fósforo e ferro. Os valores médios mais altos de potássio, cálcio e boro foram encontrados nas variedades locais, enquanto os genótipos silvestres apresentaram as médias mais elevados em magnésio, zinco, manganésio e sódio. Uma análise baseada em componentes principais e outra hierarquizada permitiram identificar os genótipos mais interessantes (oito variedades locais) relativamente aos caracteres morfológicos e à composição nutricional. No Capítulo 7 apresentam-se as conclusões gerais e as perspetivas futuras Os resultados obtidos neste trabalho podem contribuir para a definição dos melhores polinizadores para o planeamento de novos pomares e desenvolvimento de novas variedades. A diversidade genética encontrada nos genótipos silvestres e nas variedades locais pode fornecer informações relevantes para a conservação da diversidade genética ainda existente. O elevado teor em óleo e o reduzido teor em ácido linoleico podem permitir a seleção de progenitores para programas de melhoramento com o objetivo de aumentar a estabilidade do óleo e o valor nutricional dos frutos.
Hazelnut (Corylus avellana L.), belongs to the family Betulaceae and to the order Fagales. This species is native from Europe and Eastern Asia, and is cultivated for more than 5,000 years. During the last centuries, most of the cultivars were selected from local wild populations. Hazelnut is found at north and center of Portugal. Since the 90s, the production of hazelnut has declined, and could allow the lost of landraces. The evaluation of genetic diversity in wild genotypes and local populations is highly important for the use and management of the existent collections. With the aim of evaluating the genetic diversity and understanding the phylogenetic relationships among the Portuguese hazelnut landraces and reference cultivars, it were studied 58 genotypes, including landraces, wild genotypes and reference cultivars, at the morphological, molecular and biochemical levels. In Chapter 1 is presented a review of the origin and domestication of hazelnut, molecular markers, self-incompatibility alleles (S-alleles) and nutritional composition of the fruit. The evaluation of genetic diversity at the cloroplastidial DNA (cpDNA) level by microsatellites (cpSSRs), is presented in Chapter 2. Four out of ten studied loci were polymorphic. In total, 11 haplotypes were detected, and haplotype A was the most frequent in both landraces and reference cultivars. In the wild genotypes were found four exclusive haplotypes (H, I, J and L). This diversity could indicate the North of Portugal as a potential refugium during the last glacial period. The genetic diversity and the phylogenetic relationships, evaluated by inter-simple sequence repeat (ISSR) and amplified fragment length polymorphism (AFLP) markers are presented in Chapter 3. A total of 570 markers was obtained, and 541 (95.03%) revealed to be polymorphic. The similarity indexes ranged from 0.239 for reference cultivars versus wild genotypes, and 0.143 for landraces versus wild genotypes. The phylogenetic relationships distributed the hazelnuts into three groups, showing a clear separation among wild genotypes, landraces and reference cultivars. In Chapter 4 were presented the results achieved with the nuclear microsatellite (SSR) markers for the evaluation of the phylogenetic relationships. The level of polymorphism was high as verified by the mean values of expected heterozygosity (0.74), observed heterozygosity (0.71), and polymorphism information content (0.78). The dendrogram showed a clear separation of the wild genotypes, landraces and reference cultivars. These results reinforce the hypothesis that wild genotypes constitute a hotspot of diversity and provided us clues about the origin of some landraces. The results about the identification of S-alleles are presented in Chapter 5. In this study were used hazelnut landraces that were pollinated in the field with pollens from genotypes with known S-alleles. Three landraces revealed to have the S2 allele, two presented the S5 allele, and four showed one of following alleles S3, S5, S10, or S18. One landrace was compatible with the 17 S-alleles tested, and in two landraces was possible to identify two alleles, S5 and S9. The phenotypic variability and nutritional composition of the fruits are presented in Chapter 6. The landraces showed the highest average for the nut and kernel weight and oil content, while the reference cultivars presented the lowest mean values. The wild genotypes presented the highest amount of protein, and the lowest values in essential amino acids. The reference cultivars demonstrated the highest mean values for essential amino acids and for the minerals phosphorus and iron. The highest average values of potassium, calcium and boron were found in the landraces, whereas the wild genotypes presented the highest averages in magnesium, zinc, manganese, and sodium. An analysis based on the principal components and a dendrogram allowed the identification of the most interesting genotypes (eight landraces) concerning the morphological traits and the nutritional composition. In Chapter 7 are presented the general conclusions and future perspectives. The results obtained in this work, could contribute for the definition of the best pollinators for the planning of new orchards and development of new cultivars. The genetic diversity found on wild genotypes and landraces may provide relevant information for the conservation of the genetic diversity that still remains. The high oil content and the reduced amount of linoleic acid could allow the selection of progenitors for breeding programs with the goal of increasing the kernel oil stability and the nutritional value of the fruits.
Fundação para a Ciência e Tecnologia, “Programa Operacional Potencial Humano – POPH”, cofinanciado pelo Fundo Social Europeu (POPH/FSE) e por fundos nacionais (POPH-QREN)

European hazelnut is a significant crop in the Pacific Northwest, and the US ranks 4th internationally for hazelnut production. Production in the Pacific Northwest is threatened, however, by the disease eastern filbert blight (EFB) caused by the fungus Anisogramma anomala (Peck) E. Müller. To meet the challenges faced by the hazelnut industry in Oregon and Washington, the breeding program at Oregon State University has focused on developing DNA marker technology and producing EFB resistant cultivars. This study focused on developing new microsatellite markers from hazelnut transcriptome sequences and on disease resistance from three accessions ('Culpla,' 'Crvenje,' and OSU 495.072) which showed no disease symptoms following a series of inoculations. DNA markers have been useful in hazelnut breeding for marker-assisted selection, construction of genetic linkage maps, cultivar fingerprinting, and phylogeny studies. Previously developed markers include AFLP, RAPD, ISSR, and microsatellite (SSR) markers developed from enriched libraries and ISSR fragments. This study utilized the transcriptome sequence from 'Jefferson' hazelnut to mine for microsatellites, align with the genomic sequence, design primers, screen for polymorphism, and characterize and map polymorphic markers. A total of 1432 microsatellites were mined from the transcriptome sequence, and the most frequently found motifs were AG (35.8%), AT (13.3%), and AAG (12.7%), and 382 primer pairs were designed. Screening showed that 119 markers were polymorphic, and these were characterized on sets of 50 and 14 accessions. Fifty-three markers that segregated in the mapping population or in three alternate populations were mapped and assigned to linkage groups. A dendrogram showed that accessions clustered mostly according to geographic origin. These results confirm the high level of diversity present in hazelnut, and the markers developed in this study will be useful for further genetics studies in hazelnut. The three EFB resistant parents 'Culpla,' 'Crvenje,' and OSU 495.072 were subjected to two inoculation treatments: greenhouse inoculations and exposure under an inoculation structure. The accessions remained free of disease after both treatments. Progeny segregating for resistance were produced. The progeny were inoculated either in the greenhouse or under the structure, and disease response recorded for each individual. DNA was extracted from seedlings, and sets of 32 seedlings from each resistant parent were screened with previously mapped markers using PCR and capillary electrophoresis. All three resistance sources were correlated with marker A614, allowing the resistance loci to be assigned to linkage group (LG) 6. The progeny were then screened with all known microsatellite markers on LG 6, and linkage maps constructed of the marker loci and resistance loci. Markers KG821, LG628, and LG696 are especially close to the resistance loci and will be useful for marker-assisted selection. Although these resistance loci are located in the same region of LG 6 as the 'Gasaway' resistance gene, they are different from 'Gasaway,' and markers linked to resistance will be useful for introgressing and pyramiding resistance in new cultivars.
Graduation date: 2013

Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas
Os frutos secos possuem um valor nutricional, vitamínico e energético elevados, integrando-se na alimentação humana como frutos naturais crus (oleaginosas de frutos secos) e como fruto de processamento industrial (adição de sal e açúcar). Para além da área alimentar são ainda utilizados em outras áreas, como na medicina e na cosmética. Mas a crescente procura por frutos secos levou à escassez de plantas de qualidade para produção. A propagação in vitro de portaenxertos de fruteiras foi considerado o método mais rápido e eficaz na produção de espécies como amendoeiras, aveleiras e, mais recentemente, pistaceiras, pelo que deverá ser uma via para satisfazer as necessidades/ exigências do mercado atual. Neste contexto, foi objetivo desta dissertação o melhoramento de protocolos de micropropagação de porta-enxertos de amendoeira (GF677), pistaceira (UCB-1) e aveleira (Dundee) a partir de rebentos apicais, em particular para as fases de estabelecimento e de multiplicação in vitro, tendo-se testado vários clones de cada espécie e diferentes meios de cultura. Os três porta-enxertos foram estabelecidos in vitro com sucesso havendo diferenças dependentes da espécie, mas também do clone. O porta-enxerto da aveleira (Dundee) foi o que apresentou maior % de sobrevivência (51 %), sendo o clone I o que respondeu melhor (84%). O porta-enxerto de amendoeira (GF677) teve % de sobrevivência intermédia (27 %), apresentando os clones GF II e GF IV, em meios com composições hormonais distintas, os valores mais elevados (50 %). O porta-enxerto de pistaceira (UCB-1) apresentou % mais baixas de sobrevivência (23,01 %), contudo, obteve-se bastante sucesso com o clone I (41 %). Na fase de multiplicação, para além da % de sobrevivência calculou-se a % de rebentação dos explantes. Também nesta fase se detetou grande variação na % sobrevivência entre as espécies e entre clones. O porta-enxerto Dundee apresentou maior % de sobrevivência (82 %), do qual se destacou o clone II (100 %). O porta-enxerto de pistaceira obteve uma % intermédia (73 %), evidenciando-se o clone IV valor de 100 %. E o porta-enxerto de amendoeira apresentou % mais baixas de sobrevivências (41 %), contudo o clone o IV foi o que respondeu melhor (69,44 %). Todos os clones das três espécies atingiram uma rebentação de 100 %, exceto o clone II de UCB- 1 (50 %). Constatando-se que os melhores resultados ocorreram com a utilização dos meios de cultura 2, 3, 4 e 5 para os clones de GF677. O meio de cultura 3 para os clones de UCB-1. E os meios de cultura 2 e 3 para os clones de Dundee. De modo a testar-se outro tipo de explantes menos comuns na micropropagação mas mais abundantes ao longo do ano, realizou-se ainda um ensaio preliminar de indução de organogénese indireta a partir de explantes foliares. Embora com diferenças entre clones, foi nos porta-enxertos UCB-1 e Dundee onde se obteve maior formação de calli. Os trabalhos desenvolvidos tiveram resultados bastante promissores, tendo-se obtido material de qualidade para posteriores fases da micropropagação a partir dos 3 porta-enxertos. Mais estudos terão de ser agora realizados no sentido de otimizar os meios de cultura para multiplicação e estabelecimento de cada espécie e clone, bem como no delineamento de protocolos de enraizamento e aclimatização ex vitro.
Dry fruits have a high nutritional, vitamin and energy value, being integrated in human food as raw natural fruit (dry fruits oilseeds) and as a fruit from industrial processing (added salt and sugar). In addition to food, dry fruits have an important role in human health, for therapeutic/medicinal and cosmetics purposes. But the growing demand for dry fruits has led to a shortage of quality plants for production. In vitro propagation of fruit rootstocks has been considered the fastest and most effective method for producing species such as almond, hazelnut and more recently pistachio, and should therefore be a way to meet the needs/ requirements of today's market. In this context, the objective of this dissertation was to improve the almond (GF677), pistachio (UCB-1) and hazel (Dundee) rootstock micropropagation protocols from apical shoots, in particular for the in vitro establishment and multiplication stages, having tested several clones of each species and different culture media. The three rootstocks were successfully established in vitro with differences depending on species but also on clone. The hazelnut rootstock (Dundee) had the highest survival rate (51 %), witch clone I responded best (84 %). Almond rootstock (GF677) had intermediate survival % (27 %), with clones GF II and GF IV having the highest values (50 %) in media with different hormonal compositions. The pistachio rootstock (UCB-1) had lower % survival (23.01 %), however, it was quite successful with clone I (41 %). In the multiplication phase, in addition to the % survival, the explant burst % was calculated. Also at this stage large variation in % survival among species and between clones was detected. The Dundee rootstock had the highest survival rate (82 %), of which clone II stood out (100 %). The pistachio rootstock obtained an intermediate % (73 %), with a clone IV value of 100 %. And the almond rootstock had the lowest % survival (41 %), however the clone IV was the one that responded best (69.44 %). All clones of the three species reached 100% burst, except UCB-1 clone II (50%). The best results were found using culture media 2, 3, 4 and 5 for GF677 clones. Culture medium 3 for UCB-1 clones. And culture media 2 and 3 for the Dundee clones. In order to test other types of explants less common in micropropagation but more abundant throughout the year, a preliminary indirect organogenesis induction test was performed from leaf explants. Although with differences between clones, it was in the rootstocks UCB-1 and Dundee where the highest calli formation was obtained. The developed work had very promising results, having obtained quality material for later micropropagation phases from the 3 rootstocks. Further studies will now have to be done to optimize the culture media for multiplication of each species and clone, as well as in the design of rooting and acclimatization protocols ex vitro.

A aveleira (Corylus avellana L.) é uma importante espécie cultivada da família Betulaceae. Cultiva-se maioritariamente nas regiões temperadas do hemisfério norte, perto de grandes massas de água em latitudes médias. A Turquia é o maior produtor mundial, seguida de Itália e Estados Unidos da América. Portugal tem uma produção de avelã relativamente baixa. A otimização da fertilização é um aspeto importante da técnica cultural, uma vez que a disponibilidade de nutrientes influencia diretamente o crescimento das árvores e a produção de fruto. Atendendo a que no presente se procura reduzir o uso de fertilizantes convencionais, devido a alguns impactes negativos no meio ambiente, é importante avaliar estratégias de fertilização complementares, como por exemplo o uso de produtos com ação bioestimulante sobre as plantas. Neste trabalho foram utilizados dois tipos de bioestimulantes, um baseado em extratos de algas marinhas e outro em aminoácidos livres. Os produtos foram aplicados isoladamente e em complemento a adubação ao solo. Assim, foram estabelecidos seis tratamentos [fertilização NPK (NPK), NPK mais extrato de fitoalgas (Fitoalgas Green®) (NPK+FA), FA, NPK mais aminoácidos (Sprint Plus®) (NPK+SP), SP e Testemunha, não fertilizada], organizados num delineamento completamente casualizado com três repetições e três árvores por repetição. O ensaio foi instalado em Travanca, concelho de Macedo de Cavaleiros, em Trás-os-Montes num pomar de aveleiras da cultivar Ennis. Foi avaliado o efeito dos tratamentos no estado nutricional das árvores, a partir de cinco amostragem de folhas efetuadas durante dois anos, na composição mineral dos frutos e nas propriedades do solo. A modalidade testemunha mostrou concentrações de azoto nos tecidos mais baixas que as modalidades que receberam NPK devido ao fornecimento direto do nutriente. O extrato de algas marinhas manteve níveis elevados de azoto nas folhas, talvez por ter estimulado a eficiência de uso do nutriente a partir do solo. Os valores de potássio nas folhas também se revelaram tendencialmente mais elevados nos tratamentos com NPK. As concentrações de azoto e potássio nas folhas decreceram de forma marcada com a estação de crescimento, devido a efeitos de diluição com a expansão da parte aérea e a concentração dos elementos nos frutos. As propriedades do solo também variaram pouco entre tratamentos, embora o pH tenha decrescido nos tratamentos fertilizados com NPK, talvez devido à nitrificação da fração amoniacal do fertilizante.
Hazel (Corylus avellana L.) is an important cultivated species of the Betulaceae family. It is mostly cultivated in temperate regions of the northern hemisphere, close to large bodies of water in mid-latitudes. Turkey is the largest producer in the world, followed by Italy and the United States of America. Portugal has a relatively low hazelnut production. Optimizing fertilization is an important aspect of the cropping technique, as the availability of nutrients directly influences tree growth and fruit production. Given that currently there is an international focus on reducing the use of conventional fertilizers, due to some negative impacts on the environment, it is important to evaluate complementary fertilization strategies, such as the use of products with a biostimulant action on plants. In this work two types of plant biostimulants were used, one based on seaweed extracts and the other on free amino acids. The products were applied separately and in addition to soil NPK fertilization. Thus, six treatments were established [NPK fertilization, NPK; NPK plus phytoalgae extract (Fitoalgas Green®), NPK+FA; FA; NPK plus amino acids (Sprint Plus®), NPK+SP; SP; and a non-fertilized Control], arranged in a completely randomized design with three replicates and three trees per replicate. The trial was installed in Travanca, municipality of Macedo de Cavaleiros, in Trás-os-Montes, in an orchard of hazelnut trees of the Ennis cultivar. The effect of the treatments was evaluated based on the nutritional status of the trees (from five sampling of leaves carried out over two years), on the mineral composition of the fruits and on the properties of the soil. The control treatment showed lower tissue nitrogen concentrations than the treatments that received NPK due to the direct supply of the nutrient. The seaweed extract maintained high levels of nitrogen in the leaves, perhaps because it improved the efficiency of using the nutrient from the soil. Potassium values in leaves also tend to be higher in NPK treatments. The concentrations of nitrogen and potassium in the leaves decreased markedly during the growing season, due to dilution effects with the expansion of the canopy and the concentration of elements in the fruits. Soil properties also varied little between treatments, although pH decreased in treatments fertilized with NPK, perhaps due to nitrification of the ammoniacal fraction of the fertilizer.