Academic literature on the topic 'Grapes Diseases and pests'
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Journal articles on the topic "Grapes Diseases and pests":
1
Shneyder, E. Yu, E. V. Karimova, Yu A. Shneyder, and Yu N. Prikhodko. "Quarantine and particularly dangerous bacteria, phytoplasmas and viruses that pose a risk to the viticulture in Russian Federation." Horticulture and viticulture, no. 2 (May 26, 2020): 41–51. http://dx.doi.org/10.31676/0235-2591-2020-2-41-51.
Abstract:
The Russian Federation imports large quantities of planting and grafting material of grapes, including from countries where dangerous harmful organisms are spread to vineyards. Plant protection specialists in this industry, as well as grape producers, must understand the possible risk associated with the danger of the entry of quarantine disease pathogens into the Russian Federation and the potential damage if infected plant material is imported. Studies have been carried out by the staff of All-Russian Plant Quarantine Center to assess the phytosanitary risk of pests associated with the import of seedlings, stocks and grape cuttings. Based on these studies, the list of pests for the vine that have quarantine status and potentially quarantine status for the Russian Federation, in particular bacterioses, phytoplasmas and viral diseases has been established. This article describes the main diseases that affect grapes and are included in the Unified List of Quarantine Pests of the Eurasian Economic Union, as well as potentially dangerous viral diseases that are not currently included, but planned for inclusion in the Unified List, which pose a serious threat if they penetrate to the territory of the Russian Federation. From quarantine pathogens, grapes are affected by grape bacteriosis (Pierce disease of grapevine) (Xylella fastidiosa Wells et al.), bacterial blight of grapevine (Xylophilus ampelinus (Panagopoulos) Willems et al.), Flavescence dorée of grapevine (Candidatus Phytoplasma vitis), from the planned inclusion grapes are affected by red spotting of grape leaves (Grapevine red blotch-associated virus), marbling of grape leaves (Grapevine vein clearing virus) and discoloration of the leaves of Roditis grape (Grapevine Roditis leaf discoloration-associated virus). The article considers the biological peculiarities of pathogens, ways of their possible penetration and spread on the territory of the cultivation of grape in the Russian Federation, host plants of quarantine and dangerous pests, the main symptoms of diseases on plants, possible vectors, damage caused by quarantine pests in the countries of spreading, diagnostic methods, as well as areas of possible harmfulness for the Russian Federation.
2
UZUN, Ibrahim H., and Arzu BAYIR. "Distribution of Wild and Cultivated Grapes in Turkey." Notulae Scientia Biologicae 2, no. 4 (December 5, 2010): 83–87. http://dx.doi.org/10.15835/nsb245397.
Abstract:
Turkey is one of main gene centers in the world for grapes. It is believed that cultivated grapes have their origins in Turkey and the surrounding countries. Vitis vinifera ssp sylvestris is the only wild grape species in this region. That is why Turkey has a very large amount of wild grapevine populations and grape cultivars which offer to grapevine breeders a valuable gene pool. Wild grapevines have significant characters for inducing the resistence to biotic and abiotic stress factors, such as resistance to lime, drought, pests and diseases. Turkey has over 1.600 local grape cultivars, among which the majority of them are conserved at the national grape collection vineyard in Tekirda?. They are mostly used as table grapes, dried grapes or for local consumptions. Wild grapes are distributed all over the country territory, mainly in the river basins and forests. Wild grape collection vineyards were established at some universities in Turkey. These grapevines will be screened for the resistance to biotic and abiotic stress factors.
3
Ren, Zhongbo, and Jiang Lu. "113 Preliminary Study on Grafting between Vitis rotundifolia and V. vinifera Grapes." HortScience 34, no. 3 (June 1999): 461A—461. http://dx.doi.org/10.21273/hortsci.34.3.461a.
Abstract:
Non-native grape species such as V. vinifera and V. labrusca can not sustain the hot and humid environment of Florida due to their susceptibility to various diseases. Vitis rotundifolia (muscadine grapes) is native to Florida and the southeastern United States and adapted well to this climate condition. They are highly resistant to almost all grape foliage diseases and root pests such as nematode and phylloxera. Theoretically, muscadine grapes may become a valuable rootstock for bunch grapes. Unfortunately, most previous studies found that muscadine grapes were graft-incompatible with bunch grapes by normal grafting techniques. This study was to look for an alternative technique to graft V. vinifera onto muscadine rootstocks. A preliminary study indicated that bunch grape scions were successfully grafted on adult muscadine grapes. Two V. vinifera grape cultivars, `Thompson Seedless' and `Chardonnay', and two muscadine grape cultivars, `Carlos' and `Alachua', were used for this study. The muscadine grapes used as rootstocks are 6-year old field-grown vines and V. vinifera was used as scions. Using the common V-type grafting method was completely failed in more than 150 attempts. We then tried to insert the first-year buds of V. vinifera into 1- to 3-year-old muscadine canes. Surprisingly, the survival rate of the inserting buds was moderately high when `Carlos' was used as the rootstock. `Thompson Seedless'/`Carlos', `Chardonnay'/`Carlos' reached 53% and 33%, respectively. Successful grafting but lower survival rate was also obtained when `Alachua' was used as the rootstock (10% in `Thompson Seedless/`Alachua' and 3% in `Chardonny'/`Alachua'). The average survival rate of `Thompson Seedless' on the muscadine rootstocks was 36%, and `Chardonnay' was 12%. Regardless the cultivar of the scions, buds survived on `Carlos' and `Alachua' rootstocks were 44% and 5%, respectively. Results from this study indicated that V. vinifera grapes could be successfully grafted onto muscadine rootstocks. The survival rate varied depending on cultivars used for both scion and rootstock. It would be very interesting to see if resistance to certain diseases such as the Pierce's disease can be improved in those V. vinifera grape with muscadine roots and trunks derived from this preliminary study.
4
Gorbunov, I. V., and A. A. Lukyanov. "New studies of wild-growing grapes of Kuban: ecology, morphology, variability." E3S Web of Conferences 254 (2021): 01021. http://dx.doi.org/10.1051/e3sconf/202125401021.
Abstract:
The purpose of this scientific work was to find and study the variety of wild grapes as future promising sources of selection and valuable traits on the example of the territory of the natural reserve «Red Forest”. Analysis of modern scientific literature on the study of Vitaceae Juss. family biodiversity showed that there is practically no scientific information on agrestic Kuban forms and autochthones of grapes. This article represents the beginning of a new large research work on the study of wild Kuban grapes under study in the territory of Krasnodar Krai, in particular, in the state natural reserve “Red Forest”. The following methods were used in the work: route reconnaissance (during expeditions), traditional geobotanical and ampelographic, analytical. 5 isolated populations of agrestic grapes have been found on the territory of the “Red Forest” nature reserve. For the first time, these forms were studied and described by the ecological and geographical growth conditions and morphological traits of vegetative and generative spheres of grape plants. Significant variability of some indicators has been revealed. The presence of damage by pests and diseases was not visually detected. Hypothetically, these isolated grape populations may belong to Vitis vinifera ssp. Silvestris Gmel. or its variation var. Tipica Negr. (wild forest grapes). Samples were taken for further genetic analysis. This research was carried out within the framework of the RFFR grant project (contract No.19–416–230025).
5
Syrgabek, Yerkanat, and Mereke Alimzhanova. "Modern Analytical Methods for the Analysis of Pesticides in Grapes: A Review." Foods 11, no. 11 (May 31, 2022): 1623. http://dx.doi.org/10.3390/foods11111623.
Abstract:
Currently, research on the determination of pesticides in food products is very popular. Information obtained from research conducted so far mainly concerns the development of a methodology to determine the content of pesticides in food products. However, they do not describe the content of the pesticide used in viticulture in the resulting product. Over the past decade, this study has examined analytical methodologies for assessing pesticide residues in grapes. Scopus, Web of Science, Science Direct, PubMed, and Springer databases were searched for relevant publications. The phrases “pesticides” and “grapes” and their combinations were used to search for articles. The titles and annotations of the extracted articles have been read and studied to ensure that they meet the review criteria. The selected articles were used to compile a systematic review based on scientific research and reliable sources. The need to study the detection of pesticide residues in grapes using advanced analytical methods is confirmed by our systematic review. This review also highlights modern methods of sample preparation, such as QuEChERS, SPME, PLE, dLLME, and ADLL-ME, as well as the most used methods of separation and identification of pesticides in grapes. An overview of the countries where residual grape pesticide amounts are most studied is presented, along with the data on commonly used pesticides to control pests and diseases in grape cultivation. Finally, future possibilities and trends in the analysis of pesticide residues in grapes are discussed by various analytical methods.
6
Wang, Yutan, Chi Wei, Haowei Sun, and Aili Qu. "Design of Intelligent Detection Platform for Wine Grape Pests and Diseases in Ningxia." Plants 12, no. 1 (December 26, 2022): 106. http://dx.doi.org/10.3390/plants12010106.
Abstract:
In order to reduce the impact of pests and diseases on the yield and quality of Ningxia wine grapes and to improve the efficiency and intelligence of detection, this paper designs an intelligent detection platform for pests and diseases. The optimal underlying network is selected by comparing the recognition accuracy of both MobileNet V2 and YOLOX_s networks trained on the Public Dataset. Based on this network, the effect of adding attention mechanism and replacing loss function on recognition effect is investigated by permutation in the Custom Dataset, resulting in the improved network YOLOX_s + CBAM. The improved network was trained on the Overall Dataset, and finally a recognition model capable of identifying nine types of pests was obtained, with a recognition accuracy of 93.35% in the validation set, an improvement of 1.35% over the original network. The recognition model is deployed on the Web side and Raspberry Pi to achieve independent detection functions; the channel between the two platforms is built through Ngrok, and remote interconnection is achieved through VNC desktop. Users can choose to upload local images on the Web side for detection, handheld Raspberry Pi for field detection, or Raspberry Pi and Web interconnection for remote detection.
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Fadeev, Vladislav V., Agamagomed K. Radzhabov, and Vasily I. Demenko. "The results of the study of agricultural technology sustainable white wine grapes for a new generation of biological wines production." Vegetable crops of Russia, no. 5 (November 7, 2019): 52–57. http://dx.doi.org/10.18619/2072-9146-2019-5-52-57.
Abstract:
Relevance. Widely used traditional wine varieties of European-Asian grapes are characterized by a low level of resistance to disease and require multiple treatments with pesticides to preserve the crop and plants. Obtaining and introduction of sustainable varieties into production is one of the urgent problems of modern viticulture in the world and in our country, especially in the aspect of the ever wider dissemination of the principles of organic production. This is especially true for vineyards located in the coastal areas of the South of Russia, where the use of methods of chemical protection of vineyards from pests and diseases are limited to the proximity to the sea coast and the status of the resort region.Material and methods. The paper presents the results of the study of white wine grapes of the new generation with a high potential for resistance to environmental conditions and diseases. Purpose: research and development of recommendations on the use of white wine grapes of the new generation, characterized by resistance to adverse environmental conditions.Results. It is revealed that the experimental white wine varieties are characterized by a high level of adaptive capacity. In terms of productivity, new varieties are not inferior to the Sauvignon variety. Wine materials made from new resistant varieties are characterized by a high content of extractive and phenolic compounds. According to the organoleptic characteristics of wine materials from new resistant white grape varieties are at the level of the control variety. It is established that the level of stability of new grape varieties can be excluded from the technology of care of the vineyard measures to protect against major diseases, which significantly reduces the cost of production and allows you to get environmentally safe and organic products.
8
Gorbunov, I., Aleksey Luk'yanov, and Stanislav Mihaylovskiy. "Ecological conditions of growth and variability of the main morpho-biological indicators of wild forms of Kuban grapes." Agrarian Bulletin of the 213, no. 10 (November 26, 2021): 21–30. http://dx.doi.org/10.32417/1997-4868-2021-213-10-21-30.
Abstract:
Abstract. The purpose of this scientific work was to find and study the diversity of wild grapes as future promising sources of breeding and valuable traits on the example of the territory of the natural reserve “Krasnyy les”. Scientific novelty. Analysis of modern scientific literature on the study of the biodiversity of the Vitaceae Juss family. He showed that there is practically no scientific information on the Kuban wild forms and autochthons of grapes. This article is the beginning of a new large research work on the study of wild grapes of Kuban, studied in the territory of the Krasnodar Territory, in particular, in the state nature reserve “Krasnyy les”. Methods. The following methods were used: route-reconnaissance (during expeditions), traditional geobotanical and ampelographic, analytical. Results. 5 isolated populations of wild grapes were found on the territory of the natural reserve “Krasnyy les”. These forms were first studied and described according to the ecological and geographical conditions of growth and morphological features of the vegetative and generative spheres of grape plants. Significant variability of some indicators was revealed, for example: the openness of the crown of a young shoot and its degree of spider pubescence, the degree of bristly and spider pubescence of the underside of the formed leaf, the shape and corrugation of the leaf blade, etc. At the same time, the clusters of the studied wild forms of grapes are small, loose; the berries are also small, mostly black in color with a sweet tart taste. The presence of damage by pests and diseases is not visually detected. These isolated grape populations may hypothetically belong to Vitis vinifera ssp. Silvestris Gmel. or its varieties var. Tipica Negr. (wild forest grapes). Samples were taken for further genetic analysis in order to confirm or refute the above hypothesis. This study was conducted within the framework of the RFBR grant project (Contract No. 19-416-230025). Practical significance. The studied wild-growing forms of grapes can be used as promising sources of economically valuable breeding traits in the creation of new varieties, hybrid or clonal forms of grapes that are resistant to abiotic and biotic environmental factors.
9
Teissedre, Pierre-Louis. "Composition of grape and wine from resistant vines varieties." OENO One 52, no. 3 (August 3, 2018): 211–17. http://dx.doi.org/10.20870/oeno-one.2018.52.3.2223.
Abstract:
Obtaining resistant varieties to diseases without loss of organoleptic quality is a real challenge for oenology. Inter-specific hybridization of grapevines began in the 19th century and was initially aimed at introducing pest and disease resistance in offspring. Later, several breeding programmes implemented worldwide led to the development of varieties showing different characteristics such as cold-hardiness, short/long growing season, and pest resistance. Vitis vinifera grapes have preferred flavour characteristics for wine production, but they tend to be susceptible to pests, diseases, and extreme temperatures; species native to North America and East Asia are generally better adapted to these stressors. But these wild species tend to be low yielding and produce wines with undesirable sensory characteristics, including high acidity, low astringency, and excessive herbaceous or undesirable aromas. To be an innovative revolution during the 21st century, resistant varieties (actual and future) should be tested in different contexts for 3 major points: (i) vines can produce grapes without pesticides; (ii)
10
Petrova, M. O., and T. D. Chermenskaya. "Climate and Environment-Related Factors Affecting Degradation of Pesticides in Protecting Grapes against Diseases and Pests." Russian Agricultural Sciences 48, no. 4 (August 2022): 259–63. http://dx.doi.org/10.3103/s1068367422040103.
Dissertations / Theses on the topic "Grapes Diseases and pests":
1
Gutschow, Minique. "Resistance to Botrytis cinerea in parts of leaves and bunches of grapevine." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52435.
Abstract:
Thesis (MScAgric)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: Knowledge of the presence of Botrytis cinerea in morphological parts of bunches and leaves of grapevine would help to find a reliable, sensitive, and specific assay to verify the actual occurrence of latent infection, and to plan strategies for the effective control of B. cinerea bunch rot. The aim of this study was (i) to determine natural B. cinerea infection at specific sites in leaves and bunches of grapevine at different phenological stages, and (ii) to determine resistance in the morphological parts to disease expression. Bunches and leaves of the wine grape cultivar Merlot and the table grape cultivar Dauphine, were collected at pea size, bunch closure and harvest from five vineyards in the Stellenbosch and De Dooms regions respectively. The material was divided into two groups and sealed in polythene bags. The bags were lined with wet paper towels to establish high relative humidity. Leaves and bunches incubated in one group of bags were first treated with paraquat in order to terminate active host responses. These treatments provided conditions that facilitated disease expression under two host resistance levels by different inocula during the period of moist incubation. Disease expression was positively identified by lesion development, and the formation of sporulating colonies of B. cinerea at a potential infection site. Sites in leaves were the blades and petioles. Sites in bunch parts were rachises, laterals and pedicels, and on berries sites were the pedicel-end, cheek and style-end. In Dauphine, the various sites were at all stages classified as resistant to moderately resistant. However, at pea size and bunch closure, in spite of their resistance, nearly all the sites carried high to very high inoculum levels. The only exception was the berry cheek, which carried intermediate inoculum levels at pea size, and low inoculum levels at bunch closure. In nearly all sites, inoculum levels were lower at harvest. The decrease was the most prominent in petioles, rachises, laterals, pedicels and the pedicel-end of the berry. All these sites carried intermediate to low inoculum levels at harvest. In Merlot, sites constantly exibited a resistant reaction, except for the pedicel and pedicel-end of the berry, which changed from resistant at the early developmental stages to susceptible at harvest. Inoculum levels decreased during the season in the rachises and laterals, but were constantly high during the season in the pedicel and pedicel-end of the berry. According to this pattern of natural occurrence, B. cinerea fruit rot in these vineyards was not caused by colonisation of the pistil, and subsequent latency in the style end of grape berries. However, fruit rot was primarily caused by colonisation of the pedicel, and subsequent latency in the pedicel or pedicel-end of the berry. These findings furthermore support the hypothesis of increased host resistance during development, but also indicate that in the Western Cape province, inoculum in vineyards is abundant during the early part of the season, and less abundant later in the season. More information is therefore needed on the behaviour of the different types of B. cinerea inocula on the different morphological parts of grapevine to validate the pathway described for natural B. cinerea infection in vineyards. The penetration and disease expression at the different morphological parts of bunches of two grape cultivars (Dauphine and Merlot) under conditions simulating natural infection by airborne conidia was therefore investigated. The two cultivars did not differ in resistance of the berry cheek, which was at all stages classified as resistant. However, in Dauphine, latent inoculum levels in berry cheeks declined from intermediate at pea size to low at the following stages, whereas in Merlot, levels were intermediate during pea size and at harvest. Some differences between cultivars were found in the resistance of the structural bunch parts, and of their latent inoculum levels. In Dauphine, the rachis reacted susceptible at pea size, and was classified moderately resistant later in the season. Laterals and pedicels were moderate resistant at pea size, and resistant at later stages. Inoculum levels in rachises, laterals and pedicels were high at pea size, but intermediate at bunch closure and at harvest. The finding that B. cinerea infected and naturally occurred more commonly in the tissues of immature than mature bunches, that the structural parts of the bunch carried more B. cinerea than the berry cheek, and that these infections may be more important in B. cinerea bunch rot than infection of the cheek or the style end, suggest that emphasis should be placed on the disease reaction of the pedicel and related parts of immature bunches rather than on the berry. The resistanc-e reaction of leaf blades, petioles, internodes and inflorescences on cuttings, compared to those on older shoots from the vineyard were therefore investigated. In the case of vinelets, leaf blades, petioles, internodes and inflorescences were all classified susceptible to highly susceptible. The different parts furthermore all carried very high latent inoculum levels. In vineyard shoots the petioles and inflorescences showed resistance, and carried intermediate to latent inoculum levels. This finding suggests that leaf blades are not appropriate parts for studying the behaviour of inoculum of B. cinerea and host responses in grape bunches. In stead, petioles and inflorescences of vineyard shoots should be used for this purpose.
AFRIKAANSE OPSOMMING: WEERSTAND TEEN BOTRYTIS CINEREA IN MORFOLOGIESE DELE VAN BLARE EN TROSSE VAN WINGERD Kennis oor die teenwoordigheid van Botrytis cinerea in morfologiese dele van wingerd word benodig vir die ontwerp van 'n betroubare, sensitiewe en spesifieke toets vir die bevestiging van latente infeksies, en vir die implementering van strategieë vir die effektiewe beheer van B. cinerea-vrot. Die doel van hierdie studie was om (i) natuurlike B. cinerea infeksie by spesifieke areas in blare en trosse van wingerd te bepaal, en (ii) om weerstand teen siekte-uitdrukking in hierdie morfologiese dele vas te stel. Trosse en blare van die wyndruif kultivar Merlot en die tafeldruif kultivar Dauphine, is by ertjiekorrel, tros-toemaak en oes in vyf wingerde in die Stellenbosch- en De Doomsomgewing, onderskeidelik, versamel. Die materiaal is in twee groepe verdeel en in polietileen sakkies verseël. Die sakkies is met klam papierdoekies uitgevoer om sodoende hoë relatiewe humiditeit te verseker. Blare en trosse wat in die een groep geïnkubeer is, is eers met paraquat behandel om aktiewe gasheerreaksies te beëindig. Hierdie behandelings het toestande geskep wat gedurende die periode van vogtige inkubasie gunstig was vir siekteontwikkeling deur verskillende inokula by twee gasheer-weerstandsvlakke. Siekteuitdrukking is positief geïdentifiseer deur letsel-ontwikkeling en die vorming van sporuierende kolonies van B. cinerea by 'n potensiële infeksie-area. Dele waarop in die blare gekonsentreer is, was die blaarskyf en -steel. In die trosse was die dele die rachis, lateraal en korrelsteel, en op korrels was dit die korrelsteel-end, wang en styl-end. In Dauphine is die verskillende dele tydens al die fenologiese stadia as weerstandbiedend tot matig weerstandbiedend geklassifiseer. Die verskillende dele her egter, ten spyte van hul weerstandbiedendheid, hoë tot baie hoë inokulumvlakke by ertjiekorrel- en tros-toemaakstadium gedra. Die enigste uitsondering was die korrelwang, wat 'n middelmatige inokulumvlak by ertjiekorrel, en 'n lae inokulumvlak by tros-toemaak, gedra het. Die inokulumvlakke was in byna al die dele laer by oes. Die afname in inokulumvlakke was die prominentste in die blaarstele, rachi, laterale, korreisteie en die korrelsteel-end van die korrel. Al hierdie dele het 'n middelmatige tot lae inokulumvlak by oes gehad. In Merlot was die dele konstant weerstandbiedend, behalwe vir die korrelsteel en die korrelsteel-end van die korrel, wat gewissel het van weerstandbiedend by die vroeë ontwikkelingstadia, tot vatbaar by oes. lnokulumvlakke in die rachis en lateraal het gedurende die seisoen afgeneem; maar was deur die seisoen konstant hoog in die korrelsteel en korrelsteel-end van die korrel. Volgens die patroon van natuurlike voorkoms, word B. cinerea-vrot in hierdie wingerde nie deur kolonisasie van die stamper, en die daaropvolgende latensie in die styl-end van die korrels, veroorsaak nie. Vrot word egter primêr deur kolonisasie van die korrelsteel, en die daaropvolgende latensie in die korrelsteel of korrelsteel-end van die korrel, veroorsaak. Hierdie bevindinge ondersteun die hipotese van toenemende gasheerweerstand gedurende ontwikkeling, en dui ook daarop dat inokulumvlakke in wingerde in die Wes-Kaap provinsie volop is gedurende die eerste deel van die seisoen, en minder volop is later in die seisoen. Meer inligting word dus benodig aangaande die gedrag van die verskillende inokulum tipes van B. cinerea op die verskillende morfologiese dele van wingerd, ten einde die infeksieweg vir natuurlike B. cinerea infeksie in wingerde te bevestig. Die vestiging van latente infeksies in die verskillende morfologiese dele van trosse van twee kultivars (Dauphine en Merlot), onder toestande wat natuurlike infeksie deur luggedraagde konidia simuleer, is dus ondersoek. Die twee kultivars se weerstand in die korrelwang het nie verskil nie en is by alle fenologiese stadia as weerstandbiedend geklassifiseer. Die latente inokulumvlakke in die korrelwang van Dauphine het egter van middelmatig by ertjiekorrel, tot laag in die daaropvolgende stadia afgeneem, terwyl die vlakke in Merlot middelmatig by ertjiekorrel en oes was. Verskille tussen die twee kultivars is gevind ten opsigte van die weerstand in die trosdele, asook hulle latente inokulumvlakke. Die rachis van Dauphine was by ertjiekorrel vatbaar, en matig weerstandbiedend later in die seisoen. Die lateraal en korrelsteel was matig weerstandbiedend by ertjiekorrel en weerstandbiedend by latere stadia. lnokulumvlakke in rachi, laterale en korreisteie was hoog by ertjiekorrel, maar middelmatig by tros-toemaak en oes. Die bevindinge dat B. cinerea natuurlik meer algemeen in die weefsel van onvolwasse trosse voorgekom en laasgenoemde meer algemeen geïnfekteer het, dat B. cinerea se voorkoms hoër was in die morfologiese dele van die tros as in die korrelwang, en dat hierdie infeksies van groter belang in B. cinerea-vrot mag wees as infeksie van die wang of styl-end, dui daarop dat klem gelê moet word op die siektereaksie van die strukturele dele van onvolwasse trosse, eerder as van die korrel. Die weerstand van blaarskywe, blaarstele, internodes en blomtrossies van steggies, in vergelyking met die op ouer lote in wingerde, is dus ondersoek. Blaarskywe, blaarstele, internodes en blomtrossies van steggies is almal as vatbaar tot hoogs vatbaar geklassifiseer. Die verskillende dele het verder ook almal baie hoë latente inokulumvlakke gedra. By die ouer lote van wingerde het die blaarstele en blomtrossies weerstandbiedend vertoon, en middelmatige latente inokulumvlakke gedra. Hierdie bevindinge dui daarop dat blaarskywe nie die ideale morfologiese deel is vir gedragstudies van B. cinerea in druiwetrosse nie. Blaarstele en blomtrossies van ouer lote moet eerder vir die doel gebruik word.
2
Fazeli, Claudia Fariba. "Molecular detection of grapevine leafroll associated closteroviruses (GLRaVs) and the genome organisation of GLRaV-1." 1998, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phf2868.pdf.
3
Freeborough, Michael-John 1971. "A pathogen-derived resistance strategy for the broad-spectrum control of grapevine leafroll-associated virus infection." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53285.
Abstract:
Thesis (PhD)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: Grapevine leafroll-associated virus-3 is one of ten members of the C/osteroviridae that are known to infect grapevine. Nine of these viruses are associated with grapevine leafroll disease, of which GLRaV-1 and GLRaV-3 are the most important and widespread. Members of the C/osteroviridae are unique amongst the viruses, as it is the only known family whose members encode a heat shock protein 70 kOa homolog (Hsp70h). The Hsp70h is a movement protein (MP) that is required for the active translocation of the virion structure through the plasmodesmata into adjacent cells. Broad-spectrum resistance to unrelated viruses can be obtained by a pathogen-derived resistance (POR) strategy that is based on the expression of a dysfunctional MP in plants. The Hsp70h has two distinct domains. The N-terminal two thirds of the protein is an ATPase domain and shares high homology with the ATPase domains of all Hsp70h proteins from the C/osteroviridae and Hsp70 proteins from the prokaryote and eukaryote kingdoms. Conserved amino acids are found in the ATPase domain and are required for the positioning of the ATP at the catalytic site for ATP hydrolysis. The C-terminal domain is variable and the function of this domain in the Closteroviridae is not known. In prokaryote and eukaryote Hsp70 proteins, the C-terminal domain is required for protein-protein interactions. The American NY-1 isolate of GLRaV-3 has been sequenced and POR strategies have been attempted with the coat protein, divergent coat protein and replicase genes, but not with a dysfunctional form of the hsp70h gene. In this study, double-stranded RNA was isolated from a commercial vineyard with unknown virus status, but with distinct grapevine leafroll symptoms, and from two grapevine sources of known virus status, one with mild and one with severe symptoms. The GLRaV-3 hsp70h gene was amplified by RT-PCR from the dsRNA and the gene sequence was analysed. The hsp70h gene from the three virus sources contained more than 94% nucleotide sequence homology to the NY-1 isolate and the conserved amino acids required for ATPase activity were present. The hsp70h gene isolated from GLRaV-3 from a commercial Stellenbosch vineyard showing clear leafroll symptoms was selected for further work and was subjected to site-directed mutagenesis to engineer four point mutations in the gene. These four mutations resulted in the substitution of Asn for Asp", Gly for Thr1O, Lys for Glu 174 and Asn for Asp 197. The wild type (WT) and mutated (Mut) forms of the hsp 70h genes were cloned into a bacterial expression vector. Expression of both the WT- and Mut-Hsp proteins was achieved, and the protein was expressed in the insoluble inclusion bodies. All attempts to refold and isolate active proteins from the inclusion bodies were unsuccessful. Attempts to increase the concentration of soluble protein within the expressing bacteria were unsuccessful. Due to the lack of active protein, biochemical tests on the ATPase activity of the WT- and Mut-Hsp proteins could not be conducted. The wt- and mut-hsp genes were cloned into a plant expression vector for transformation into tobacco plants. These transformations were successful and gave rise to 22 Km' and 18 Km' plants from the WT- and Mut-Hsp constructs respectively. Two plant lines, M5 and M10, transformed with the mut-hsp transgene construct, appeared to have a high level of resistance to the challenging potato X potexvirus, whereas all the other tested plants were susceptible to the challenging virus. It was thus shown that a dysfunctional form of the GLRaV-3 Hsp70h could provide resistance to an unrelated virus in tobacco.
AFRIKAANSE OPSOMMING: Wingerdrolblaar-geassosieerde virus 3 (GLRaV-3) is een van 10 lede van die Closteroviridae wat wingerd kan infekteer. Nege van die virusse is met wingerdrolblaar geassosieer. Die GLRaV-1 en GLRaV-3 is die belangrikste en mees wyd verspreide lede van die rolblaar-geassosieerde Closteroviridae. Lede van die Closteroviridae is uniek in die opsig dat die virusse vir 'n 70 kDa-homoloë hitteresponsproteïen (Hsp70h) kodeer. Die Hsp70 is 'n bewegingsproteïen (MP) wat belangrik is vir die translokasie van die virus deur die plasmodesmata na die naasliggende sel. Breë-spektrum weerstand teen onverwante virusse kan behaal word deur 'n patogeen-afgeleide weerstandstrategie (POR), wat op die uitdrukking van 'n disfunksionele MP wat in plante uitgedruk word, gebaseer is. Die Hsp70hproteïen het twee gebiede. Die N-terminale gebied is In ATPase-gebied en toon hoë homologie met ander ATPase-gebiede van Hsp70h-proteïene van die Closteroviridae, asook die prokariotiese en eukariotiese koninkryke. Gekonserveerde aminosure wat belangrik is vir die posisionering van ATP in die katalitiese domein vir ATP-hidrolise is in die ATPase-gebied gevind. Die C-terminale gebied is variërend en die funksie van die gebied in die Closteroviridae is onbekend. In prokariotiese en eukariotiese Hsp70h-proteïene is die C-terminale gebied belangrik vir proteïenproteïen interaksies. Die nukleotiedvolgorde van die Amerikaanse NY-1-isolaat van GLRaV-3 is al bepaal en POR-strategieë is ook op die kapsiedproteïen, uiteenlopende kapsiedproteïen en die replikasie-proteïen uitgevoer, maar nog nie op 'n disfunksionele vorm van die Hsp70h-geen nie. In hierdie studie is dubbelstring-RNA (dsRNA) van 'n kommersiële wingerd met onbekende virusstatus wat rolblaarsimptome toon, geïsoleer, asook van twee wingerde met 'n bekende virusstatus, een met ligte en een met strawwe simptome. Die GLRaV-3 hsp70h-geen is met hulp van die polimerasekettingreaksie-metode (PKR) vanaf die dsRNA geamplifiseer en die geen se nukleotiedvolgorde is bepaal. Die hsp 70-gene van drie verskillende wingerde het meer as 94% homologie met die NY-1-isolaat getoon. Die gekonserveerde aminosure wat vir ATPase-aktiwiteit belangrik is, was teenwoordig. Die hsp70h-geen van GLRaV-3, wat uit 'n kommersiële wingerd met duidelike rolblaarsimptome in die Stellenbosch-gebied geïsoleer is, is vir verdere navorsing gekies en dit is aan setel-gerigte mutagenese blootgestelom vier mutasies van die geen te bewerkstellig. Die gevolg van hierdie vier mutasies was die verandering van Asn na Asp", Gly na Thr1o, Lys na Glu174 en Asn na Asp197. Die wilde (WT) en veranderde (Mut) vorms van die hsp-gene is in 'n bakteriese uitdrukkingsvektor gekloneer. Uitdrukking van beide die WT- en die Mut-Hspproteïene is behaal, maar die proteïene was in die onoplosbare fraksie geleë. Pogings om die onoplosbare proteïene te isoleer en in 'n aktiewe oplosbare vorm te verkry, was onsuksesvol. Verdere pogings om die proteïene in die oplosbare fraksie van die bakteriese ekspressiesisteem uit te druk, was ook onsuksesvol. As gevolg van die gebrek aan aktiewe proteïen kon biochemiese toetse nie op die ATPaseaktiwiteit van die WT- en Mut-Hsp proteïne gedoen word nie. Die wt- en mut-hsp-gene is ook in In plantekspressievektor gekloneer vir transformasie in tabakplante. Hierdie transformasies was suksesvol en het aanleiding gegee tot 22 kanamisienbestande (Km') en 18 Km' plante vanaf die WT- en Mut-Hspkonstrukte onderskeidelik. Twee plantlyne, M5 en M10, wat met die mut-hsptransgene getransformeer is, het 'n hoë vlak van weerstand teen die infekterende aartappelvirus X getoon in vergelyking met ander plante wat met die virus geïnfekteer is. Daar is dus bewys gelewer dat 'n disfunksionele vorm van die GLRaV-3 Hsp70h weerstand kan bied teen 'n onverwante virus in tabak.
4
Constable, Fiona Elizabeth. "Biology and epidemiology of Australian grapevine phytoplasmas." Title page, contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phc756.pdf.
5
White, Chana-Lee. "The characterization of the basidiomycetes and other fungi associated with esca of grapevines in South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5319.
Abstract:
Thesis (MSc (Plant Pathology))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Esca is a disease affecting grapevines and is potentially devastating as there are economic losses due to a decrease in yield, wine quality and berry quality. Vineyards also need to be replaced earlier and therefore esca has a great impact on the wine, table grape and raisin industries. The disease is known to affect vineyards worldwide and has been studied extensively in Europe, but not in South Africa. Esca diseased grapevines were observed for the first time prior to 1981 in South African vineyards. The disease is primarily caused by Phaeoacremonium aleophilum, Phaeomoniella chlamydospora (both causing brown and black wood streaking) and white rot basidiomycete species such as Fomitiporia mediterranea which cause wood rot in the trunks and arms of generally older grapevines. Species of the Botryosphaeriaceae and Phomopsis (mainly Phomopsis viticola) and Eutypa lata have also been isolated from esca diseased vines, but their association with esca is unclear. Some of the symptoms associated with the disease on most grapevine cultivars include ‘tiger-stripe’ foliar symptoms, apoplexy and berry symptoms such as shriveling, discoloration and ‘black measles’. These external symptoms as well as internal symptoms are thought to be a result of toxin and enzyme production by the fungi involved. Symptom expression is erratic and varies from year to year making investigations into the causal fungi and the toxins and enzymes secreted in planta difficult. Vines with internal or external symptoms of esca were sampled in this study from table and wine grape cultivars in 37 towns in the Western Cape, Northern Cape and Limpopo provinces. The majority of sampled vines were over ten years of age, but vines as young as two to three years were also found to be infected. The external symptoms included dieback, tiger striped leaves, berry symptoms (shriveling, insufficient colouring and black spots) and apoplexy. These symptoms resembled those found on grapevines in Europe, Australia and the USA. The internal symptoms found were also similar to European symptoms and included white rot, black and brown wood streaking, brown necrosis within white rot, sectorial brown necrosis and central brown/ red/ black margin. The fungi mostly isolated from the white rot were the basidiomycetes. Black and brown wood streaking was primarily caused by Phaeomoniella chlamydospora. Brown necrosis within the white rot was caused by Phaeomoniella chlamydospora and less frequently by Phaeoacremonium spp., Eutypa lata, Botryosphaeriaceae and Pleurostomophora richardsiae. The sectorial brown necrosis and the central/ brown/ red/ black margin were dominated by Phaeomoniella chlamydospora. The fruiting bodies of the basidiomycetes were found on only a few grapevines. The fungal species associated with the internal wood symptoms were characterized on cultural growth patterns, morphology as well as phylogenetic inference. The gene areas sequenced included the internal transcribed spacers and the 5.8S rRNA gene for the basidiomycetes and Phomopsis isolates, the partial b-tubulin gene for Phaeoacremonium isolates and the partial translation elongation-1a gene for the Botryosphaeriaceae isolates. The basidiomycete isolates fell into ten taxa within the Hymenochaetales of which two could be linked to known genera, namely Fomitiporia and Phellinus. The ten basidiomycete taxa do not correspond to any published sequences. Eutypa lata, Diaporthe ambigua, Diplodia seriata, Neofusicoccum australe, Neofusicoccum parvum, Phomopsis viticola, Phomopsis sp. 1, Phaeomoniella chlamydospora and six species of Phaeoacremonium including P. aleophilum, P. alvesii, P. parasiticum, P. iranianum, P. mortoniae and P. sicilianum were also isolated of which the latter three are reported for the first time in South Africa. To understand the role of the basidiomycetes in the complex, toxin and enzyme analyses was determined for these fungi. Selected basidiomycete isolates were grown up in liquid broth and extractions performed to test for the presence of 4-hydroxy-benzaldehyde. All of the basidiomycete isolates were able to produce this toxin which is known to be phytotoxic. The basidiomycetes were then tested for the presence of certain wood degrading enzymes. All of the taxa were able to produce manganese peroxidase. Laccase was produced by all taxa, except Taxon 8. Lignin peroxidase was produced by Taxa 1, 2, 7, Fomitiporia sp. and the Phellinus sp. All the basidiomycete isolates were able to produce cellulose and none were able to produce xylanase. These enzyme tests showed that the basidiomycetes produce a wide variety of enzymes which are able to degrade cellulase and lignin which are both structural components of wood. Given the wide distribution of esca in the grape growing regions investigated in South Africa and the diverse amount of species found, this disease must surely be seen as a limiting factor to the productive lifespan of vineyards and quality of produce. Preventative measures such as sanitation and pruning wound protection contribute to the management of the disease, but many questions still remain about the synergy of the causal fungi, epidemiology and management of esca.
AFRIKAANSE OPSOMMING: Esca is ‘n wingerd siekte wat potensieel skade kan aanrig as gevolg van ekonomiese verliese weens verlaagde opbrengs, wyn kwaliteit en vrug kwaliteit. Wingerde moet ook vroeër vervang word en daarom het esca ’n groot impak op die wyn, tafeldryf en rosyne industrieë. Esca word wêreldwyd gevind op wingerd en is al intensief nagevors in Europa, maar nog nie in Suid-Afrika. Esca is vir die eerste keer in die 1980’s in Suid-Afrikaanse wingerde gerapporteer. Die primêre veroorsaakende organismes van esca is Phaeoacremonium aleophilum, Phaeomoniella chlamydospora wat bruin en swart vaatweefsel verkleuring veroorsaak en basidiomycete spesies soos Fomitiporia mediterranea wat wit verotting veroorsaak in die stam en arms van ouer wingerd. Spesies van die Botryosphaeriaceae en Phomopsis (hoofsaaklik Phomopsis viticola) en Eutypa lata is ook al vanaf esca simptome geïsoleer, maar hul assosiasie met die siekte is nie duidelik nie. Algemene simptome wat voorkom op die meeste wingerd kultivars met esca sluit in ‘tiger-stripe’ blaar simptome, apopleksie en vrug simptome soos verdroging, verkleuring en spikkels (black measles). Interne en eksterne simptome kan wees as gevolg van toksiene en ensiem produksie van die swamme wat betrokke is by esca. Eksterne simptoom uitdrukking is wisselvallig en varieer van jaar tot jaar. Dit bemoelik die bestudering van die swamme en die toksiene en ensieme wat afgeskei word in planta. Wingerd monsters met eksterne en interne simptome is versamel van tafel en wyndruif kultivars in 37 dorpe in die Wes-Kaap, Noord-Kaap en Limpopo provinsies. Die meerderheid monsters was ouer as tien jaar maar wingerde wat twee tot drie jaar oud was, was ook gevind. Die eksterne simptome wat op hierdie kultivars gevind is het terugsterwing, ‘tiger striped’ blare, vrug simptome (verkrimping en onvoldoende verkleuring) en apopleksie ingesluit. Hierdie simptome stem ooreen met soortgelyke simptome gevind op wingerd in Europa, Australië en die VSA. Interne simptome was ooreenstemmend met simptome wat gevind word in Europa. Die interne simptome het wit verotting, bruin en swart streepvorming, bruin nekrose met wit verotting, sektoriale bruin nekrose en sentrale bruin/ rooi/ swart kante ingesluit. Basidiomycete swamme is meestal uit die wit verotting gedeeltes geïsoleer. Swart en bruin hout streepvorming was meestal deur Phaeomoniella chlamydospora veroorsaak. Bruin nekrose binne die wit verotting was meestal deur Phaeomoniella chlamydospora veroorsaak en in ‘n mindere mate deur Phaeoacremonium spp., Eutypa lata, Botryosphaeriaceae en Pleurostomophora richardsiae. Phaeomoniella chlamydospora was die hoof veroorsakende organisme van sektoriale bruin nekrose en die sentrale bruin/ rooi/ swart kante. Vrugliggame van die basiodiomycete is op enkele wingerde gevind. Swam soorte wat geassosieer word met die interne hout simptome was verder gekarakteriseer op kultuur groei, morfologiese eienskappe, en filogenetiese analise. Die geen areas waarvan die basis paar volgorde bepaal was sluit in die interne getranskribeerde spasies en die 5.8S rRNA geen vir die basidiomycete en Phomopsis isolate, die gedeeltelike btubulien geen vir Phaeoacremonium isolate en die gedeeltelike translasie velenging-1a geen vir die Botryosphaericeae isolate. Die basidiomycete isolate was versprei oor tien taksons binne die Hymenochaetales waarvan twee genusse gekoppel kon word aan die genera Fomitiporia en Phellinus. Die tien basidiomycete taksons kom nie ooreen met enige gepubliseerde DNS volgordes. Eutypa lata, Phomopsis viticola, Phomopsis sp. 1, Diaporthe ambigua, Diplodia seriata, Neofusicoccum parvum, Neofusicoccum australe, Phaeomoniella chlamydospora en ses spesies van Phaeoacremonium insluitend P. aleophilum, P. alvesii, P. parasiticum, P. iranianum, P. mortoniae en P. sicilianum is ook geïsoleer. Hierdie is die eerste keer dat P. iranianum, P. mortoniae en P. sicilianum in Suid-Afrika gerapporteer word. Om die rol wat die basidiomycete in die siekte-kompleks speel beter te verstaan is toksien en ensiem analises uitgevoer. Geselekteerde basidiomycete isolate is gekweek in vloeibare groei medium en ekstraksies uitgevoer om te toets vir die teenwoordigheid van 4- hydroxy-benzaldehyde. Al die basidiomycete isolate kon 4-hydroxy-benzaldehyde, wat bekend is om fitotoksies te wees, produseer. Die basidiomycete isolate was verder getoets vir die produksie van spesifieke hout afbrekende ensieme. Al die basidiomycete taksons kon mangaan-peroksidase produseer. Lakkase was geproduseer deur al die taksons, uitsluitend Takson 8. Lignien-peroksidase was geproduseer deur Taksons 1, 2, 7, Fomitiporia sp. en die Phellinus sp. Al die basidiomycete isolate kon sellulose produseer, maar geen kon xilanase produseer. Die ensiem analises het gewys dat die basidiomycete wat moontlik betrokke is by esca ‘n wye reeks van ensieme kan produseer wat sellulose en lignien kan degradeer. Sellulose en lignien is beide strukturele komponente van hout. Weens die wye verspeiding van esca geaffekteerde wingerde in Suid Afrika en die wye reeks van spesies wat betrokke is by die siekte kompleks moet esca sekerlik gesien word as een van die beperkende faktore op die produktiewe leeftyd van wingerde en die kwaliteit van druiwe wat geproduseer word. Sanitasie en snoeiwond beskerming is voorkomende maatreëls wat ingestel kan word om die effek en verspreiding van esca te beperk maar daar is nog baie vrae wat antwoorde benodig oor die sinergie van die veroorsakende swamme, epidemiologie en bestuur van esca.
6
Mostert, Lizel. "The characterization and control of Phomopsis cane and leaf spot on vine." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51945.
Abstract:
Thesis (MScAgric.)--Stellenbosch University, 2000.ENGLISH ABSTRACT: Phomopsis cane and leaf spot disease of grapevine is an economically important disease in many of the vine-growing areas of the world. Four different Phomopsis spp. have previously been associated with this disease. The present study investigates the taxonomic significance of the different taxa found on grapevines in South Africa, as well as the endophytic growth and fungicide sensitivity of Phomopsis viticola isolates. The thesis is compiled of several different parts, which deal with specific, but related topics, and hence some duplication has been unavoidable. Understanding the epidemiology of a disease is important for the correct timing of disease control. To investigate the endophytic growth of P. viticola, asymptomatic shoots were collected at eight different growth stages. Nodes, internodes, leaf petioles, leaves, tendrils and bunch peduncles were investigated. Two Phomopsis spp., taxon 1 and 2 were identified in this study. The Phomopsis viticola-complex had a relative importance of 9% and accounted for 3% of the isolations. P. viticola (taxon 2) is mainly isolated from the nodes and internodes. Inoculations of healthy, young vine tissue confirmed taxon 2 to be a virulent pathogen, suggesting that it is a latent pathogen rather than an endophyte. In contrast, taxon 1 appeared to be a true endophyte, and did not seem to be an important pathogen on vines. The true identity of the causal organism of Phomopsis cane and leaf spot disease was investigated by collecting samples from 58 different vineyards in the grapevine growing areas of the Western Cape. P. viiicola occurred in grapevine material collected from Lutzville to Swellendam, but was not found in the Oudtshoorn and Orange River grapevine areas. Diaporthe perjuncta (taxon 1), P. vutcola (taxon 2), taxon 3 and a Phomopsis species commonly associated with shoot blight of peaches in the U.S.A., P. amygdali, were identified among the South African grapevine isolates. Examination of the Australian culture designated as taxon 4 found it to be a species of Libertella, thus excluding it from the P. viticola-complex. An Italian isolate was found to represent a species of Phomopsis not previously known from grapevines, and this was subsequently described as taxon 5. Species delimitation was based on morphological and cultural characteristics, stem inoculations and the formation of the teleomorph in vitro. The identity of each morphological taxon was confirmed by means of phylogenetic analyses of the nuclear ribosomal DNA internal transcribed spacers (ITS 1 and ITS2) and the 5' end partial sequence of the mitochondrial small subunit (mtSSU). P. amygdali, associated with peach shoot blight in the U.S.A., was isolated once only and appeared to be of lesser importance in this disease complex. Furthermore, taxa 1 (Diaporthe perjuncta) and 3 were also rarely encountered and proved to be non-pathogenic, indicating their non-functional role in Phomopsis cane and leaf spot disease. Taxon 2 (Phomopsis viticolas was common and widely distributed in diseased vineyards. This taxon was associated with the typical disease symptoms and proved to be pathogenic. Morphologically taxon 2 corresponded best with P. viticola, which was also neotypified in this study. Taxon 2 was mostly isolated from buds and nodes, indicating that these are important sites in which the fungus survives during winter. Molecular data indicated that taxon 3 and P. amygdali were not host specific to grapevine. The currently used foliar fungicides were compared to the new strobilurin fungicides. The effects of nine fungicides (azoxystrobin, flusilazole, folpet, fosetyl- Al+mancozeb, kresoxim-methyl, mancozeb, penconazole, spiroxamine and trifloxystrobin) were tested in vitro on inhibition of mycelial growth. The following EC50 (ug/ml) values were obtained: azoxystrobin (0.350), flusilazole (0.007), folpet (4.489), fosetyl-Al+mancozeb (3.925), kresoxim-methyl (1.665), mancozeb (2.891), penconazole (0.023), spiroxamine (0.321) and trifloxystrobin (0.051). Additionally, azoxystrobin, folpet, kresoxim-methyl, mancozeb, propineb and trifloxystrobin were tested for their ability to inhibit spore germination in vitro. The subsequent EC50 (ug/ml) values were obtained: azoxystrobin 0.123), folpet (0.510), kresoxim-methyl (0.0037), mancozeb (0.250), propineb (0.156) and trifloxystrobin (0.003). The results reported in part 4 showed that the strobilurin fungicides inhibited the mycelial growth and spore germination of P. viticola. However, further trials need to be conducted to verify these findings under field conditions. In the present study taxa 1, 3 and P. amygdali were infrequently isolated, suggesting that they played a less prominent role in the P. viticolacomplex.
AFRIKAANSE OPSOMMING: Streepvleksiekte van wingerd is 'n ekonomies belangrike siekte wat in die meeste wingerdproduserende gebiede van die wêreld voorkom. Vier Phomopsis spesies is in die verlede met dié siekte geassosieer. Hierdie studie ondersoek die taksonomiese belangrikheid van die verskillende taksa wat op wingerd in Suid Afrika gevind word, asook die endofietiese groei en fungisiedsensitiwiteit van die Phomopsis vitico/a isolate. Hierdie tesis bestaan uit verskeie dele met spesifieke, maar verwante onderwerpe wat tot onafwendbare duplisering lei. Dit is belangrik om die epidemiologie van 'n siekte te verstaan sodat korrekte en tydsberekende siektebeheer toegepas kan word. Die endofietiese groei van P. vitico/a is ondersoek deur simptoomlose lote by agt verskillende groei stadiums te versamel. Nodusse, internodusse, blaarstele, blare, rankies en trosstele is ondersoek. Twee Phomopsis spp., takson 1 en 2 is geïdentifiseer. Die Phomopsis vitico/a-kompleks het 3% van die isolasies uitgemaak en 'n relatiewe belangrikheid van 9% getoon. P. vitico/a (takson 2) is meestal uit die nodus en internodus geïsoleer. lnokulasies van gesonde, jong wingerdweefsel het bevestig dat takson 2 'n virulente patogeen is en dat die takson eerder 'n latente patogeen as 'n endofiet is. In teenstelling hiermee is takson 1 'n ware endofiet en 'n onbelangrike patogeen op wingerd. Die ware identiteit van die veroorsakende organisme van streepvlek is ondersoek deur plantmateriaal vanaf 58 verskillende wingerde in die wingerproduserende gebiede van die Wes-Kaap te versamel. P. vitico/a is in wingerdmateriaal vanaf Lutzville tot Swellendam aangetref, maar nie in die Oudtshoorn en Oranjerivier wingerd produserende gebiede nie. Diaporthe perjuncta (takson 1), P. vitico/a (takson 2), takson 3 en P. amygdali is in die Suid Afrikaanse wingerdisolate geïdentifiseer. P. amygdali word met lootverskroeiing van perske bome in die V.S.A. geassosieer. Die Australiese isolaat wat benoem is as takson 4, is met die huidige ondersoek gevind om 'n spesie van Libertella te wees. Takson 4 is daarvolgens uit die P. vitico/a-kompleks gelaat. 'n Italiaanse isolaat het 'n nuwe spesie van Phomopsis op wingerd verteenwoordig en is vervolgens as takson 5 beskryf. Spesie-onderskeiding is op morfologiese en kulturele eienskappe, staminokulasies en die vorming van die teleomorf in vitro gebaseer. Die identiteit vanelke morfologiese takson is met behulp van filogenetiese analises van die nukleêre ribosomale DNS intern transkriberende spasieerders (ITS 1 en ITS2) en die 5' punt gedeeltelike nukleotied volgorde van die mitochondriale klein subeenheid (mtSSU) bevestig. P. amygdali is slegs een keer geïsoleer en blyk van minder belang in die siektekompleks te wees. Takson 1 (Diaporthe perjuneta) en takson 3 het ook min voorgekom en is nie-patogenies, wat hul nie-funksionele rol in streepvleksiekte aandui. Takson 2 (P. viticola) is algemeen geïsoleer en kom wyd verspreid voor. Hierdie takson is geassosieer met die tipiese siektesimptome en is ook patogenies. Morfologies stem takson 2 met P. viiicola ooreen en is ook geneotipifiseer in hierdie studie. Takson 2 is meestal vanaf die ogies en nodusse geïsoleer, wat daarop dui dat hierdie belangrike setels is waar die swam tydens die winter oorleef. Die molekulêre data toon aan dat takson 3 en P. amygdali nie gasheerspesifiek tot wingerd is nie. Die swamdoders wat tans teen streepvlek gebruik word, is met die nuwe strobilurin swamdoders vergelyk. Die effek van nege swamdoders (azoksistrobin, flusilasool, folpet, fosetyl-Al + mancozeb, kresoxirn-metiel, mankozeb, penconasool, spiroksamien en trifloksistrobin) is in vitro op die inhibisie van miseliumgroei getoets. Die volgende EKso-waardes (g/ml) is verkry: azoxystrobin (0.350), flusilasool (0.007), folpet (4.489), fosetiel-Al + mankozeb (3.925), kresoxirn-metiel (l.665), mankozeb (2.891), penkonasool (0.023), spiroksamien (0.321) en trifloxystrobin (0.051). Azoxystrobin, folpet, kresoxim-rnetiel, mankozeb, propineb en trifloksistrobin is ook in vitro getoets vir hul inhibisie op spoorontkieming. Die volgende EKso-waardes is verkry: azoxystrobin (0.123), folpet (0.510), kresoxim-metiel (0.0037), mankozeb (0.250), propineb (0.156) en trifloxystrobin (0.003). Die resultate vervat in deel 4 toon dat die strobilurin swamdoders die miseliumgroei en spoorontkieming van P. viticola inhibeer. Toetsing in die veld word egter benodig om die effektiwiteit van die middels te bevestig. In hierdie studie is taksa I, 3 en P. amygdali selde geïsoleer, wat aangedui het dat hierdie taksa 'n minder belangrike rol in die P. viticola-kompleks speel.
7
Du, Preez Izak Frederik. "Infection pathways of Botrytis cinerea on selected wine grape cultivars." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52889.
Abstract:
Thesis (MScAgric)--University of StellenboschENGLISH ABSTRACT: An understanding of the infection pathways of Botrytis cinerea in grape bunches will help to combat this devastating pathogen of grape. Many studies have been done to determine the possible infection pathways of B. cinerea. Most of these studies made use of artificial inoculations that deposit groups of conidia on the plant surface. The deposition of clusters of conidia is not a common phenomenon in nature. The aim of this study was to investigate the infection pathways of (i) naturally- as well as (ii) artificially inoculated B. cinerea conidia during all the phenological stages of three wine grape cultivars, and to compare the (iii) pathogenicity and virulence, on grape and nectarine fruit, of isolates obtained from different host plants. In the natural infection study the occurrence of Botrytis cinerea and subsequent disease expression at different positions in bunches of wine grapes (cultivars Chenin Blanc, Shiraz and Chardonnay) was determined from 1999 to 2001. Different techniques were used to detect viable inoculum at different positions (rachises, laterals, pedicels, and the peicel end, cheek and style end of berries) in bunches. Isolations were made on Kerssies' B. cinerea selective medium, or bunches were used untreated, or treated with paraquat. Paraquat was used to terminate host resistance and to promote the development of the pathogen from the tissues. The material was used untreated to detect the pathogen on the surface, or were surface-sterilized to detect mycelia (latent infection) in the tissue. In the artificial inoculation study, bunches of wine grapes (cultivars Chenin Blanc, Chardonnay and Shiraz) at pea size, bunch closure, and harvest were dusted with dry conidia of Botrytis cinerea in a settling tower and incubated for 24 h at high relative humidity (±93%). Following incubation, the bunches were divided in two groups. The one group was surface-sterilised in 70% ethanol for 5 s, the other group was left untreated. Bunches of the sterile group, and from the untreated group were used for isolation. From each bunch rachis segments, laterals, pedicels and berry skin segments (from the pedicel-end and cheek) were removed. The sections were placed in Petri dishes on Kerssies' B. cinerea selective medium and on a water agar medium supplemented with paraquat, and incubated at 22°C under diurnal light. Occupation by the pathogen was positively identified by the formation of sporulating colonies of B. cinerea on the different tissues. Lastly, in the virulence and pathogenicity experiment on grape and nectarine fruit Botrytis cinerea isolates, which were obtained from different host plants, were compared by simulating natural infection. Cold-stored fruit, considered highly susceptible to B. cinerea were therefore inoculated with single, airborne conidia of the pathogen. Different tests were conducted to assess surface penetration and lesion formation. Isolations were made from fruit skins on Kerssies' B. cinerea selective medium. Nectarine fruit were treated with paraquat, and grape berries were frozen for 1 h at -12°C. Paraquat and freezing were used to terminate host resistance and to promote the development of the pathogen from the tissues. In the natural infection studies B. cinerea occurred in a consistent pattern in bunches of the three cultivars. B. cinerea consistently developed from the tissue of the rachis, laterals, pedicel and pedicel-end, but not from the berry cheek. The rachis, lateral and pedicel contained much higher levels of B. cinerea than any position on the berry. Furthermore, the pathogen consistenly occurred at relatively high levels on the rachises throughout the season. Collectively, the data showed that in the Western Cape province, B. cinerea occured more regularly in wine grape bunches during the early part of the season, than later in the season. The data of the artificial studies confirmed the findings made with the natural infection studies. In these experiments the pathogen resided more often on the structural bunch parts than on the berries. Overall, the isolation studies revealed that conidia occurred predominantly on the rachis. The incidence of B. cinerea was furthermore constantly high in the inner bunch after each inoculation, and in bunches of different maturities. The data therefore indicated that, when available, conidia penetrated loose and tight clustered bunches in a similar way. Finally, in the virulence and pathogenicity experiments the results showed clearly that no host specialisation exists in the B. cinerea isolates used in this study. From these studies it is clear that in the Western Cape province B. cinerea occurs more readily in the inner structural parts of the bunches and more so during the earlier parts of the season. These findings should be considered when planning and implementing disease control programmes.
AFRIKAANSE OPSOMMING: INFEKSIEWEË VAN BOTRYTIS CINEREA OP GESELEKTEERDE WYNDRUIF KULTIVARS Indiepte kennis van die infeksieweë van Botrytis cinerea op druiwetrosse word benodig vir die beheer van dié vernietigende patogeen van druiwe. Vele studies is al gedoen om die moontlike infeksieweë van die swam op druiwe trosse te ondersoek. Die meeste van die studies het gebruik gemaak van kunsmatige inokulasie tegnieke waar die konidia van die swam in groepe op die korreloppervlak gedeponeer is. In die natuur is dit 'n rare verskynsel dat konidia in groepe op die korreloppervlak land. Die doel van die studie was om die infeksieweë van B. cinerea op drie wyndruif kultivars te ondersoek wat (i) natuurlik- en (ii) kunsmatig geïnokuleer is met konidia gedurende al die fenologiese stadia, en om die (iii) virulensie en patogenisisteit van isolate wat van verskillende gashere verkry is, op druiwe en nektariens te vergelyk. In die natuurlik-geïnokuleerde druiwe is die voorkoms van B. cinerea en die gevolglike siektevoorkoms op verkillende posisies in trosse van wyndruiwe (Chenin Blanc, Chardonnay, Shiraz) gedurende 1999 tot 2001 bepaal. Verskillende tegnieke is gebruik om lewensvatbare inokulum by verskillende posisies (ragis, lateraal, pedisel en pedisel-end van die korrel) in die tros waar te neem. Isolasies is op Kerssies' B. cinerea selektiewe medium gemaak, of trosse is onbehandeld gebruik, of behandel met paraquat. Paraquat is gebruik om die gasheer se natuurlike weerstand te verlaag en om die ontwikkeling van die patogeen te bevorder. Die plantmateriaal is onbehandeld gelaat om die patogeen op die oppervlak waar te neem, of die oppervlak is gesteriliseer om die latente myselium in die weefsel waar te neem. In die kunsmatige inokulasiestudies is trosse, van wyndruiwe (Chenin Blanc, Chardonnay, Shiraz), geïnokuleer met droë spore, van B. cinerea, in 'n inokulasietoring en die plantmateriaal is dan geinkubeer vir 24 h by 'n hoë relatiewe humiditeit (93%). Na die inkubasie proses is die trosse in twee groepe verdeel. Die een groep druiwe het oppervlak sterilisasie ondergaan in 70% etanol vir 5 s, en die ander groep was onbehandeld gelaat. Trosse van die onbehandelde en gesteriliseerde groep druiwe is gebruik vir isolasies. Vanuit elke tros is daar segmente van die ragis, laterale, pediselle en korrels (van die pedisel-end en wang gedeeltes) geïsoleer. Die segmente is in Petri bakkies met Kerssies' B. cinerea selektiewe medium en op water agar medium, wat paraquat bevat het, geïsoleer en geïnkubeer onder 'n 12 h dagligperiode teen 22°C. Die patogeen is positief geïdentifiseer deur sporuierende kolonies op die onderskeie weefseltipes. Laastens, in die virulensie- en patogenisiteitsproewe op druiwe en nektariens is verskillende isolate van B. cinerea, verkry vanaf verskillende gasheerplante, vergelyk deur natuurlike inokulasie toestande na te boots. Koue opgebergde vrugte, wat beskou word as hoogs vatbaar vir die infeksie van B. cinerea, is geïnokuleer met droë, enkel luggedraagde spore van die patogeen. Verskillende toetse is gedoen om die oppervlak penetrerende en letselvormende vermoëns van die onderskeie isolate te toets. Isolasies is van die skille van die vrugte gemaak en op Kerssies' B. cinerea selektiewe medium geplaas. Die nektarienvrugte is met paraquat behandel en die druifkorrels is gevries vir 1 h teen -12°C. Paraquat en bevriesing is gebruik om die gasheer se weerstand te verlaag en om die ontwikkeling van die patogeen te bevorder. In die natuurlik-geïnokuleerde studies het B. cinerea 'n konstante patroon getoon in die trosse van die drie verskillende wyndruif kultivars. B. cinerea het konstant ontwikkel uit die ragis, laterale, pedisel en pedisel-end, maar selde uit die korrelwang. Die ragis, lateral en pedisel dele het baie hoër vlakke van van die swam bevat as enige deel op die korrel. Die patogeen het ook konstant volop deur die hele seisoen op die ragis voorgekom. Gesamentlik wys die data dat, B. cinerea in wyndruiwe, in die Wes Kaap provinsie, meer geredelik vroeër in die seisoen voorkom, eerder as later. Data van die kunsmatige inokulasiestudies het die bevindinge van die natuurlike inokulasiestudies tot 'n groot mate bevestig. In dié studies het die patogeen meer geredelik die strukturele dele van die tros, eerder as op die korrels, bewoon. Oor die algemeen het die isolasieproewe gewys dat die konidia meer op die ragis voorkom as op enige ander deel. Die voorkoms van B. cinerea was ook oor die algemeen baie hoër in die strukturele dele van die tros, as op die korrel self. Die verskynsel het onder trosse van verskillende ontwikkelingsvlakke voorgekom. Die data het dus ook gewys dat konidia, wanner dit beskikbaar is, minder- sowel as meer kompakte trosse op 'n soortgelyke manier penetreer. Laastens, in die virulensie en patogenisiteitseksperimente het die resultate duidelik gewys dat daar geen gasheer spesifieke gedrag onder B. cinerea isolate is nie. In die studies het dit duidelik na vore gekom dat, B. cinerea meer geredelik in die strukturele binne dele van die wyndruif tros, in die Wes Kaap provinsie voorkom. En so ook eerder aan die begin van die seisoen, as later in die seisoen. Dié kennis moet in aanmerking geneem word by die beplanning en implementering van siektebeheerprogramme.
8
Evans, Katherine J. "Characterization of Uncinula necator, the grapevine powdery mildew fungus." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phe924.pdf.
Abstract:
Bibliography: leaves 148-166. This study identifies genetic variation in Australian Uncinula necator populations. Techniques were developed for molecular and phenotypic markers for U. necator. Mating types of Australian clonal lines were identified and viable cleistothecia and infective ascospores were produced in vitro. The study establishes the foundation for investigating the population biology of U. necator, by identifying two distinct genetic groups, A and B, and micro-geographical variation among 35 clonal lines from various Australian viticultural regions.
9
Groenewald, Michelle. "Characterization and control of Phaeomoniella chlamydospora in grapevines." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51650.
Abstract:
Thesis (MScAgric)--University of Stellenbosch, 2000.ENGLISH ABSTRACT: Petri grapevme decline, also known as black goo, slow die-back and Phaeoacremonium grapevine decline, causes significant losses of young vines worldwide. Species of Phaeoacremonium, Phaeomoniella chlamydospora and related genera are associated with this grapevine disease. This study investigates the Phaeoacremonium-complex and Phaeomoniella chlamydospora, focussing on the species isolated from grapevines. Fungicide sensitivity of Pa. chlamydospora and the possibility of employing molecular techniques for the detection of Pa. chlamydospora in grapevines were also investigated. In an overview of the literature on Petri grapevine decline the disease history and the relatedness of Petri grapevine decline to esca is discussed. Petri grapvine decline occurs in propagation material or young vines. Infected material can appear asymptomatic and therefore the possibilities of molecular techniques for identification were also investigated in the literature. In South Africa Pa. chlamydospora is the dominant organism causing Petri grapevine decline and therefore different fungicides were evaluated to control this fungus. Six isolates of Pa. chlamydospora, from Stellenbosch, Wellington, Somerset West and Malmesbury of Western Cape province, South Africa, were screened against twelve fungicides testing their effect on mycelial inhibition in vitro. These fungicides included benomyl, chlorothalonil, fenarimol, fosetyl-Al, iprodione, kresoxim-methyl, mancozeb, metalaxyl, prochloraz manganese chloride, quintozene, tebuconazole and thiram. Results provided the base-line sensitivity of South African isolates of Pa. chlamydospora. Benomyl, fenarimol, kresoxim-methyl, prochloraz manganese chloride and tebuconazole were the most effective (with EC50 values ranging from 0.01 to 0.05 ug/ml) for inhibiting mycelial growth of Pa. chlamydospora in vitro. This in vitro test gave a good indication of which fungicides could be selected for further studies in glasshouses and nurseries. The molecular phylogeny of Phaeoacremonium and Phaeomoniella isolates from grapevines of South Africa, or isolates obtained from the Centraalbureau voor Schimmelcultures (CBS) in the Netherland, were investigated. Sequence data were created from the rONA region and partial B-tubulin gene of 33 of these isolates using the PCR technique. This sequence data were analysed with PAUP* version 4.Ob2a. An analysis of the sequence data confirmed the genus Phaeomoniella to be distinct from Phaeoacremonium (Pm.) based on DNA phylogeny. Although morphologically similar, the species status of Pm. aleophi/um and Pm. angustius was confirmed with DNA phylogeny and cultural characteristics. Pm. aleophilum has an optimum growth rate at 30°C and the ability to grow at 35°C, where as Pm. angustius has an optimum growth rate at 25°C and cannot grow at 35°C_ Pm. viticola was shown to be synonymous with Pm. angustius, and a new species, Pm. mortoniae, was newly described from grapevine occurring in California. Futhermore, Pm. aleophilum was newly reported from South Africa and grapevine isolates thought to be Pm. inflatipes were all re-identified as Pm. aleophilum. These findings therefore also shed some doubt on the possible role of Pm. inflatipes in Petri grapevine decline. It was confirmed that Pa. chlamydospora, Pm. aleophilum and Pm. angustius are the species involved in Petri grapevine decline. Pm. mortoniae was isolated from grapevines, but its pathogenicity should still be confirmed and the role of Pm. injlatipes in Petri grapevine decline remains unclear. Pa. chlamydospora has been routinely isolated from symptomless propagation and nursery material. Because the disease can take years to develop, it is crucial that healthy propagation material is used at planting. Pa. chlamydospora is a slowgrowing fungus, and positive identification from symptomless grapevine tissue can take up to 4 wks. The possibility of employing molecular techniques for the detection of Pa. chlamydospora in apparently healthy grapevines was investigated. Speciesspecific primers (PCLI and PCL2) based on the regions ITSI and ITS2 were designed for Pa. chlamydospora. These primers were highly sensitive and amplification was achieved from genomic DNA of Pa. chlamydospora from as low as 16 pg. Phaeoacremonium spp., related genera and common fungal taxa from grapevines were tested with these primers, but positive amplification was achieved for Pa. chlamydospora only. The presence of Pa. chlamydospora in symptomless grapevine tissue culture plants was confirmed by PCR within 24 hours. These primers therefore allow rapid and accurate identification of Pa. c~lamydospora. Testing on a larger scale with nursery material should be conducted to determine the feasibility of using these species-specific primers in the grapevine industry.
AFRIKAANSE OPSOMMING: Petri-terugsterwing van jong wingerde, ook algemeen bekend as "black goo" en Phaeoacremonium-terugsterwing, veroorsaak wêreldwyd groot geldelike verliese in die wingerdbedryf. Spesies van Phaeoacremonium, Phaeomoniella chlamydospora en verwante genera word met hierdie wingerdsiekte geassosieer. In die tesis word In oorsig gegee van die geskiedenis van hierdie siekte, die verwantskap tussen Petriterugsterwing en esca, en moontlike maniere van siektebestuur. Swamme wat by die siektekompleks betrokke is, kan in simptoomlose plantweefsel voorkom en daarom is die moontlikhede van die gebruik van molekulêre tegnieke vir swamidentifikasie in oënskou geneem. In Suid-Afrika is Pa. chlamydospora die dominante swam wat met Petriterugsterwing geassosieerword, gevolglik is verskillende fungisiedes vir die chemiese beheer van Pa. chlamydospora geëvalueer. Ses isolate van Pa. chlamydospora, versamel vanaf verskillende areas in die Wes-Kaap provinsie, is in dié studie gebruik. Benomyl, chlorothalonil, fenarimol, fosetyl-Al, iprodione, kresoxim-methyl, mancozeb, metalaxyl, prochloraz manganese chloride, quintozene, tebuconazole en thiram se effek op miselium inhibisie van Pa. chlamydospora is in vitro geëvalueer. Benomyl, fenarimol, kresoxim-methyl, prochloraz manganese chloride en tebuconazole was die mees effektiewe middels. Die effektiewe konsentrasie waarby 50% van die miselium groei geïnhibeer is (EKso),was tussen 0.01 en 0.05 ug/ml vir die mees effektiewe groep middels. Benomyl, fenarimol, kresoxim-methyl, prochloraz manganese chloride en tebuconazole het in vitro goeie potensiaal getoon, en verder toetse moet in vivo uitgevoer word. 'n Molekulêre studie is van Phaeoacremonium en Phaeomoniella isolate; verkry uit Suid-Afrikaanse wingerde, of vanaf die "Centraalbureau voor Schimmelcultures" (CBS) van Nederland; gedoen. Deur van die PKR tegniek gebruik te maak, is die basispaaropeenvolgingsdata van 33 isolate, van die ITSl, 5.8S, ITS2 rDNA area en die gedeeltelike B-tubullen geen verkry. Gekombineerde molekulêre data het die teorie ondersteun dat Phaeomoniella (Herpotrichiellaceae) gedistansieerd is van Phaeoacremonium (Magnaporthaceae). Pm. aleophilum en Pm. angustius was morfologies moeilik onderskeibaar, maar kon op grond van molekulêre data en kulturele eienskappe onderskei word. Pm. aleophilum se optimum groeitemperatuur was by 30°C en die swam besit die vermoë om by 35°C te groei. Pm. angus/ius se optimum groeitemperatuur was by 25°C, maar het nie by 35°C gegroei nie. 'n Studie van molekulêre en kulturele eienskappe het getoon dat Pm. angus/ius en Pm. viticola sinoniem is. 'n Nuwe spesie, Pm. mortoniae, wat uit wingerde van Kalifornie geïsoleer is, is beskrywe. Verder is Pm. aleophilum die eerste keer in Suid-Afrikaanse wingerde aangetref en Pm. tnflatipes isolate, wat vanuit wingerde geïsoleer is, is almal met molekulêre data gewys om Pm. aleophilum te wees. Hierdie bevindinge trek die rol van Pm. inflatipes in Petri-terugsterwing van wingerde in twyfel. Phaeomoniella chlamydospora IS m voortplantingsmateriaal en kwekerystokkies opgespoor. Omdat dit jare kan duur voordat siektesimptome ontwikkel, is dit belangrik om vroegtydig te weet of jong stokkies met Pa. chlamydospora geïnfekteer is. Pa. chlamydospora groei baie stadig en positiewe identifikasie van simptoomlose infeksies duur tot vier weke. Die toepassing van molekulêre tegnieke vir die vinnige identifikasie van Pa. chlamydospora in wingerde is dus ondersoek. Spesie-spesifieke oligonukleotiedes (PCU en PCL2) is vir Pa. chlamydospora ontwerp. Hierdie oligonukleotiedes is uiters sensitief en genomiese DNA van Pa. chlamydospora is van so laag as 16 pg geamplifiseer. Phaeoacremonium spp., verwante genera en algemene swamme vanuit wingerdmateriaal is met die oligonukleotiedes getoets, maar positiewe amplifikasie was slegs met Pa. chlamydospora moontlik. Die teenwoordigheid van Pa. chlamydospora is binne 24 uur in asimptomatiese wingerd weefselkultuurplantjies bevestig. Hierdie oligonukleotiedes identifiseer Pa. chlamydospora vinnig en akkuraat en toetsing op 'n groter skaal moet vervolgens met kwekerymateriaal onderneem word.
10
Moyo, Mukani. "Molecular and phenotypic characterisation of grapevines expressing non-vinifera PGIP encoding genes." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6825.
Abstract:
Thesis (MSc)--University of Stellenbosch, 2011.ENGLISH ABSTRACT: Plants are constantly exposed to biotic and abiotic stress inducing factors that threaten their existence. Biotic factors such as pathogens are the cause of huge yield losses to crop plants worldwide with fungal pathogens debatably constituting the worst damage. Fungal pathogens such as Botrytis cinerea, which has a wide host range, release cell wall degrading enzymes called endopolygalacturonases (ePGs) during plant infection. These ePGs break down the pectin component of the cell wall, thus providing an entry route, as well as nutrients for the fungus. Plants have evolved mechanisms to counteract and suppress the action of the ePGs. This is achieved through the action of cell wall associated proteins called polygalacturonaseinhibiting proteins, PGIPs. PGIPs directly inhibit ePGs and their inhibitory action also prolongs the existence of longer chain oligogalacturonide residues which are believed to elicit a cascade of defence responses. In grapevine, a PGIP encoding gene, VvPGIP1, was previously isolated and characterised. VvPGIP1, as well as nine non-vinifera grapevine PGIPs have been expressed in tobacco and shown to be potent antifungal proteins that caused the transgenic tobacco to have strong resistance phenotypes against Botrytis in whole plant infection assays. Following on the tobacco study, two of the non-vinifera PGIPs were expressed in cultivars of the susceptible Vitis vinifera. Characterisation of the putative transgenic population showed that transgene integration was successful, the transgenes were being expressed and there were at least 29 transgenic lines with independent integration events. The transgenic lines were confirmed to have active PGIPs (transgene-derived) in their leaves. Crude protein extracts from 22 lines exhibited 100% inhibition against crude B. cinerea PGs (BcPGs). The plant lines with positive transgene integration, expression, independent integration events and exhibiting 100% transgene-derived PGIP activity were further selected for whole plant and detached leaf antifungal assays where they were challenged with B. cinerea. The whole plant infection assay showed that expression of the non-vinifera PGIPs in V. vinifera promotes susceptibility to B. cinerea, not resistance. This surprising result could perhaps be explained by a quicker and stronger recognition between the pathogen and the host and the stronger activation of defence responses in the host. A more active hypersensitive response in the host would benefit Botrytis being a necrotroph. The type of lesions and the onset and speed of lesion development observed on the transgenics lines versus the wild type support this possibility. Knowledge gaps with regards to the efficiency of the ePG inhibition by the nonvinifera PGIPs during infection of grapevine tissue; the potential changes that might be caused by expressing PGIPs in a grapevine host with a native PGIP with high homology to the transgenes (including potential gene silencing) and the potential impact on defence signalling and defence responses all provides further avenues of study to elucidate this very interesting phenotype further. Overall, this study provides a comprehensively characterised population of transgenic plants that provides useful resources for in vivo analysis of PGIP function in defence, where the host plant harbours a native copy of the PGIP encoding gene.
AFRIKAANSE OPSOMMING: Plante word voortdurend blootgestel aan biotiese en abiotiese faktore, wat stres veroorsaak en hul bestaan bedreig. Biotiese faktore, soos patogene, veroorsaak groot verliese in wêreldwye gewasopbrengste, met swampatogene wat moontlik die grootste skade veroorsaak. Swampatogene, soos Botrytis cinerea, wat ‘n wye reeks gasheerplante kan infekteer, stel selwand-afbrekende ensieme tydens plantinfeksie vry, wat as endo-poligalakturonases (ePG’s). bekend staan. Hierdie ePG’s breek die pektienkomponent van die selwand af, wat gevolglik as ‘n ingangspunt dien,asook voedingstowwe vir die swam verskaf. Plante het meganismes ontwikkel om die aktiwiteit van hierdie ePG’s te bekamp en te onderdruk. Die aktiwiteit van die selwand-geassosieërde proteïene, genaamd poligalakturonase-inhiberende proteïene (PGIP’s), speel hier ‘n rol. PGIP’s inhibeer ePG’s direk en hul inhiberende aktiwiteit verleng ook die bestaan van langketting oligogalakturoniedresidu’s, wat blykbaar ‘n kaskade van weerstandsreaksies kan inisieer. ‘n PGIP-koderende geen, VvPGIP1, is voorheen uit wingerd geïsoleer en gekarakteriseer. VvPGIP1, asook nege nie-vinifera wingerd-PGIP’s is voorheen in tabak uitgedruk en bevestig as proteïene met sterk anti-swamaktiwiteit, soos bevestig deur die bevinding dat die transgeniese tabak ‘n weerstandsfenotipe teen Botrytis in heelplant-infeksietoetse het. Ná die tabakstudie is twee van die nie-vinifera PGIP’s uitgedruk in vatbare V. vinifera-kultivars. Karakterisering van die vermeende transgeniese bevolking het getoon dat die transgeen-integrasie suksesvol was, dat die transgeen uitgedruk word en dat daar ten minste 29 transgeniese lyne met onafhanklike integrasie gebeurtenisse geskep is. Daar is verder bevestig dat die transgeniese lyne aktiewe PGIP’s (transgeen-afkomstig) in hul blare het. Ongesuiwerde proteïenekstrakte van 22 lyne het 100% inhibisie teen ‘n mengsel van ongesuiwerde B. cinerea PGs (BcPGs) getoon. Die plantlyne met positiewe transgeenintegrasie en -uitdrukking, asook onafhanklike integrasiegebeure en wat 100% transgeen-afkomstige PGIP-aktiwiteit getoon het, is verder aan heel-plant en verwyderde blaarswaminfeksies met B cinerea onderwerp. Die heelplantinfeksietoetse het getoon dat uitdrukking van nie-vinifera PGIP’s in V. vinifera ‘n toename, in plaas van ‘n afname, in vatbaarheid teen B. cinerea veroorsaak. Hierdie verbasende resultaat kan moontlik toegeskryf word aan ‘n vinniger en sterker herkenningsreaksie tussen patogeen en gasheer en die moontlike sterker stimulering van weerstandsreaksies in die gasheer. ‘n Meer aktiewe hipersensitiewe reaksie in die gasheer sal tot die voordeel van Botrytis, wat ‘n nektrotroof is, wees. Die tipe letsel, asook die aanvang en spoed van letselontwikkeling wat waargeneem is in transgeniese lyne teenoor die wilde-tipe ondersteun hierdie moontlikheid. Gapings in kennis ten opsigte van die doeltreffendheid van die ePG-inhibisie deur die nievinifera PGIP’s tydens infeksie van wingerdweefsel, die moontlike veranderinge (insluitend ‘n moontlike geenuitdowingseffek) wat veroorsaak kan word deur die uitdrukking van PGIP-gene in ‘n kultivar met ‘n inheemse en baie homoloë PGIP-geen, kon ‘n invloed op weerstandseine en weerstandsreaksies gehad het. Hierdie aspekte lewer verdere studiemoontlikhede om hierdie interessante fenotipe verder te verklaar.Algeheel lewer hierdie studie ‘n breedvoeriggekarakteriseerde bevolking trangeniese plante, wat dien as nuttige hulpbronne vir in vivoanalise van PGIP se funksie in siekteweerstandbiedendheid, veral waar die gasheerplant ‘n inheemse kopie van die PGIP-koderende geen huisves.
Books on the topic "Grapes Diseases and pests":
1
Watson, John W. Grape phylloxera. Pullman: Cooperative Extension, College of Agriculture & Home Economics, Washington State University, 1990.
2
Bettiga, Larry J. Grape pest management. Oakland, California: University of California, Agriculture and Natural Resources, 2013.
3
Compant, Stéphane, and Florence Mathieu. Biocontrol of major grapevine diseases: Leading research. Boston, MA: CABI, 2016.
4
Pavli︠u︡kova, T. P. Osobennosti vedenii︠a︡ vinogradnikov v Chernomorskoĭ zone Krasnodarskogo krai︠a︡: Monografii︠a︡. Krasnodar: [publisher not identified], 2010.
5
Pavli︠u︡kova, T. P. Osobennosti vedenii︠a︡ vinogradnikov v ukryvnoĭ zone: (agrotekhnika i zashchita rasteniĭ). Krasnodar: Severo-Kavkazskiĭ zonalʹnyĭ NII sadovodstva i vinogradarstva, 2008.
6
ʻĀrif, Maḥmūd ʻAbbās al-Ḥājj. Shajarat al-karmah. 8th ed. Dimashq: Jāmiʻat al-Duwal al-ʻArabīyah, al-Markaz al-ʻArabī li-Dirāsāt al-Manāṭiq al-Jāffah wa-al-Arāḍī al-Qāḥilah (Aksād), Idārat al-Mawārid al-Nabātīyah, 2013.
7
Bebee, Charles N. The protection of grapes and cherries, 1979-April 1989: Citations from AGRICOLA concerning diseases and other environmental considerations. Beltsville, Md: U.S. Dept. of Agriculture, National Agricultural Library, 1989.
8
Garrier, Gilbert. Le phylloxéra: Une guerre de trente ans, 1870-1900. Paris: A. Michel, 1989.
9
Boehm, Wally. The phylloxera fight: Protecting South Australia from the phylloxera threat. Adelaide: Winetitles in association with the Phylloxera and Grape Industry Board of South Australia, 1996.
10
International Workshop on Grapevine Downy Mildew Modeling (1st 26-30 August, 1991 Geneva, N.Y.). Proceedings of the first International Workshop on Grapevine Downy Mildew modeling: Cornell University, New York State Agricultural Experiment Station, Geneva, New York, USA. Geneva, NY: Dept. of Plant Pathology, NYS Agricultural Experiment Station, 1994.
Book chapters on the topic "Grapes Diseases and pests":
1
Plumb, R. T. "The effects of pests and diseases on grasses." In The Grass Crop, 277–309. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-1187-1_8.
2
Chougule, Archana, Vijay Kumar Jha, and Debajyoti Mukhopadhyay. "AgroKanti: Location-Aware Decision Support System for Forecasting of Pests and Diseases in Grapes." In Advances in Intelligent Systems and Computing, 677–85. New Delhi: Springer India, 2016. http://dx.doi.org/10.1007/978-81-322-2755-7_70.
3
Kulkarni, N. S. "Pests of Grapes." In Pests and Their Management, 517–57. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-8687-8_16.
4
Kulkarni, N. S. "Sucking Pests of Grapes." In Sucking Pests of Crops, 425–50. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-6149-8_14.
5
Thompson, Anthony Keith, and Ibok Oduro. "Diseases and pests." In Yams: botany, production and uses, 76–90. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789249279.0006.
Abstract:
Abstract This chapter describes the different diseases and pests that affect yams and various methods for their control. It particularly covers the following aspects: field fungal diseases; postharvest fungal diseases; specific fungal diseases; control of fungal diseases; bacterial diseases; viral diseases; physiological disorders; insect pests; and nematode pests.
6
Laksono, N. D., U. Setiawati, F. Nur, M. Rahmaningsih, Y. Anwar, H. Rusfiandi, B. P. Forster, E. H. Sembiring, A. S. Subbarao, and H. Zahara. "Pests and diseases." In Nursery practices in oil palm: a manual, 77–85. Wallingford: CABI, 2019. http://dx.doi.org/10.1079/9781789242140.0077.
7
Collins, Brian, Jessie Baldwin, Kristina Martinez, Mary Ann Lila, and Michael McIntosh. "Grapes and Gastrointestinal Health: Implications with Intestinal and Systemic Diseases." In Grapes and Health, 119–38. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-28995-3_7.
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Tayal, Mukesh K., and T. P. S. Chauhan. "Silkworm Diseases and Pests." In Industrial Entomology, 265–89. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-3304-9_9.
9
Hunsigi, Gururaj. "Weeds, Pests and Diseases." In Advanced Series in Agricultural Sciences, 144–56. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-78133-9_8.
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Sipes, B., and A. P. de Matos. "Pests, diseases and weeds." In The pineapple: botany, production and uses, 269–94. Wallingford: CABI, 2018. http://dx.doi.org/10.1079/9781786393302.0269.
Conference papers on the topic "Grapes Diseases and pests":
1
Chougule, Archana, Vijay Kumar Jha, and Debajyoti Mukhopadhyay. "Ontology Based System for Pests and Disease Management of Grapes in India." In 2016 IEEE 6th International Conference on Advanced Computing (IACC). IEEE, 2016. http://dx.doi.org/10.1109/iacc.2016.34.
2
Yan, Lihua, and Shuqin Li. "Grape Diseases and Pests Named Entity Recognition Based on BiLSTM-CRF." In 2021 IEEE 4th Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC). IEEE, 2021. http://dx.doi.org/10.1109/imcec51613.2021.9482206.
3
Munkvold, Gary P. "Managing Diseases and Pests with Seed Treatments." In Proceedings of the 16th Annual Integrated Crop Management Conference. Iowa State University, Digital Press, 2007. http://dx.doi.org/10.31274/icm-180809-893.
4
Tumang, Gina S. "Pests and Diseases Identification in Mango using MATLAB." In 2019 5th International conference on Engineering, Applied Sciences and Technology (ICEAST). IEEE, 2019. http://dx.doi.org/10.1109/iceast.2019.8802579.
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Patil, Suyash S., and Sandeep A. Thorat. "Early detection of grapes diseases using machine learning and IoT." In 2016 Second International Conference on Cognitive Computing and Information Processing (CCIP). IEEE, 2016. http://dx.doi.org/10.1109/ccip.2016.7802887.
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Wang, Qiyao, Guiqing He, Feng Li, and Haixi Zhang. "A novel database for plant diseases and pests classification." In 2020 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC). IEEE, 2020. http://dx.doi.org/10.1109/icspcc50002.2020.9259502.
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Patel, Pruthvi P., and Dineshkumar B. Vaghela. "Crop Diseases and Pests Detection Using Convolutional Neural Network." In 2019 IEEE International Conference on Electrical, Computer and Communication Technologies (ICECCT). IEEE, 2019. http://dx.doi.org/10.1109/icecct.2019.8869510.
8
Kulikov, M. A., A. N. Kulikova, and A. V. Goncharov. "Resistance of sunflower hybrids to herbicides, diseases, pests and weeds." In Растениеводство и луговодство. Тимирязевская сельскохозяйственная академия, 2020. http://dx.doi.org/10.26897/978-5-9675-1762-4-2020-158.
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Alfarisy, Ahmad Arib, Quan Chen, and Minyi Guo. "Deep learning based classification for paddy pests & diseases recognition." In ICMAI '18: 2018 International Conference on Mathematics and Artificial Intelligence. New York, NY, USA: ACM, 2018. http://dx.doi.org/10.1145/3208788.3208795.
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Xiaopeng, Dai, and Li Donghui. "Research on Rice Pests and Diseases Warning Based on CBR." In 2013 Fifth International Conference on Computational and Information Sciences (ICCIS). IEEE, 2013. http://dx.doi.org/10.1109/iccis.2013.454.
Reports on the topic "Grapes Diseases and pests":
1
Solomon, J. D., T. D. Leininger, A. D. Wilson, R. L. Anderson, L. C. Thompson, and F. I. McCracken. Ash pests: a guide to major insects, diseases, air pollution injury, and chemical injury. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station, 1993. http://dx.doi.org/10.2737/so-gtr-096.
2
Solomon, J. D., T. D. Leininger, A. D. Wilson, R. L. Anderson, L. C. Thompson, and F. I. McCracken. Ash pests: a guide to major insects, diseases, air pollution injury, and chemical injury. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station, 1993. http://dx.doi.org/10.2737/so-gtr-96.
3
Kosiba, Alexandra, Emma Tait, Gene Desideraggio, Alyx Belisle, Clarke Cooper, and James Duncan. Threats to the Urban Forest: The potential economic impacts of invasive forest pests and diseases in the Northeast. Forest Ecosystem Monitoring Cooperative, June 2020. http://dx.doi.org/10.18125/8w9j42.
4
Davis, Cristina, Amots Hetzroni, Alexander Aksenov, Michael J. Delwiche, Victoria Soroker, and Victor Alchanatis. Development of a universal volatile compound detection technology for early recognition of pests and diseases in fruit trees. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600016.bard.
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Amanor, Kojo, Joseph Yaro, Joseph Teye, and Steve Wiggin. Ghana’s Cocoa Farmers Need to Change Gear: What Policymakers Need to Know, and What They Might Do. Institute of Development Studies (IDS), March 2022. http://dx.doi.org/10.19088/apra.2022.008.
Abstract:
Cocoa farmers in Ghana face increasing challenges. In the past, many of them could make a living from cocoa thanks to the advantages – ‘forest rents’ – that initially apply when forest is cleared to create cocoa farms: fertile soils, few pests and diseases. With time, however, weeds invade, pests and diseases build up, and trees age. To maintain production requires more labour, more inputs and more skill. In the past, farmers would often abandon older groves and seek new forest to clear. As they did so, the frontier for cocoa farming moved westwards across Ghana to the remaining high forest. But by 2000 or so, no new forest was available. Farmers now have to manage aging stands of trees, clear weeds and parasites, and combat pests, fungi and diseases. In Suhum District in the east and in Juaboso District in the far west of Ghana, we talked to farmers. They understood the challenges they faced, and knew how to deal with some of them. But many were not farming their cocoa as well as they could, losing yields and income as a result. This brief provides a basis for policymakers to move forward in responding to the current challenges facing cocoa farmers.
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Kanner, Joseph, Edwin Frankel, Stella Harel, and Bruce German. Grapes, Wines and By-products as Potential Sources of Antioxidants. United States Department of Agriculture, January 1995. http://dx.doi.org/10.32747/1995.7568767.bard.
Abstract:
Several grape varieties and red wines were found to contain large concentration of phenolic compounds which work as antioxidant in-vitro and in-vivo. Wastes from wine production contain antioxidants in large amounts, between 2-6% on dry material basis. Red wines but also white wines were found to prevent lipid peroxidation of turkey muscle tissues stored at 5oC. The antioxidant reaction of flavonoids found in red wines against lipid peroxidation were found to depend on the structure of the molecule. Red wine flavonoids containing an orthodihydroxy structure around the B ring were found highly active against LDL and membrane lipid peroxidation. The antioxidant activity of red wine polyphenols were also found to be dependent on the catalyzer used. In the presence of H2O2-activated myoglobin, the inhibition efficiency was malvidin 3-glucoside>catechin>malvidin>resveratol. However, in the presence of an iron redox cycle catalyzer, the order of effectiveness was resveratol>malvidin 3-glucoside = malvidin>catechin. Differences in protein binding were found to affect antioxidant activity in inhibiting LDL oxidation. A model protein such as BSA, was investigated on the antioxidant activity of phenolic compounds, grape extracts, and red wines in a lecithin-liposome model system. Ferulic acid followed by malvidin and rutin were the most efficient in inhibiting both lipid and protein oxidation. Catechin, a flavonal found in red-wines in relatively high concentration was found to inhibit myoglobin catalyzed linoleate membrane lipid peroxidation at a relatively very low concentration. This effect was studied by the determination of the by-products generated from linoleate during oxidation. The study showed that hydroperoxides are catalytically broken down, not to an alcohol but most probably to a non-radical adduct. The ability of wine-phenolics to reduce iron and from complexes with metals were also demonstrated. Low concentration of wine phenolics were found to inhibit lipoxygenase type II activity. An attempt to understand the bioavailability in humans of antocyanins from red wine showed that two antocyanins from red wine were found unchanged in human urine. Other antocyanins seems to undergo molecular modification. In hypercholesterolemic hamsters, aortic lipid deposition was significantly less in animals fed diets supplemented with either catechin or vitamin E. The rate of LDL accumulation in the carotid arteries was also significantly lower in the catechin and vitamin E animal groups. These results suggested a novel mechanism by which wine phenolics are associated with decreased risk of coronary heart diseases. This study proves in part our hypothesis that the "French Paradox" could be explained by the action of the antioxidant effects of phenolic compounds found at high concentration in red wines. The results of this study argue that it is in the interest of public health to increase the consumption of dietary plant falvonoids. Our results and these from others, show that the consumption of red wine or plant derived polyphenolics can change the antioxidant tone of animal and human plasma and its isolated components towards oxidative reactions. However, we need more research to better understand bioavailability and the mechanism of how polyphenolics affect health and disease.
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Boyle, M., and Elizabeth Rico. Terrestrial vegetation monitoring at Cumberland Island National Seashore: 2020 data summary. National Park Service, September 2022. http://dx.doi.org/10.36967/2294287.
Abstract:
The Southeast Coast Network (SECN) conducts long-term terrestrial vegetation monitoring as part of the nationwide Inventory and Monitoring Program of the National Park Service (NPS). The vegetation community vital sign is one of the primary-tier resources identified by SECN park managers, and it is currently conducted at 15 network parks (DeVivo et al. 2008). Monitoring plants and their associated communities over time allows for targeted understanding of ecosystems within the SECN geography, which provides managers information about the degree of change within their parks’ natural vegetation. 2020 marks the first year of conducting this monitoring effort at Cumberland Island National Seashore (CUIS). Fifty-six vegetation plots were established throughout the park from May through July. Data collected in each plot included species richness across multiple spatial scales, species-specific cover and constancy, species-specific woody stem seedling/sapling counts and adult tree (greater than 10 centimeters [3.9 inches {in}]) diameter at breast height (DBH), overall tree health, landform, soil, observed disturbance, and woody biomass (i.e., fuel load) estimates. This report summarizes the baseline (year 1) terrestrial vegetation data collected at Cumberland Island National Seashore in 2020. Data were stratified across three dominant broadly defined habitats within the park, including Coastal Plain Upland Open Woodlands, Maritime Open Upland Grasslands, and Maritime Upland Forests and Shrublands. Noteworthy findings include: 213 vascular plant taxa (species or lower) were observed across 56 vegetation plots, including 12 species not previously documented within the park. The most frequently encountered species in each broadly defined habitat included: Coastal Plain Upland Open Woodlands: longleaf + pond pine (Pinus palustris; P. serotina), redbay (Persea borbonia), saw palmetto (Serenoa repens), wax-myrtle (Morella cerifera), deerberry (Vaccinium stamineum), variable panicgrass (Dichanthelium commutatum), and hemlock rosette grass (Dichanthelium portoricense). Maritime Open Upland Grasslands: wax-myrtle, saw greenbrier (Smilax auriculata), sea oats (Uniola paniculata), and other forbs and graminoids. Maritime Upland Forests and Shrublands: live oak (Quercus virginiana), redbay, saw palmetto, muscadine (Muscadinia rotundifolia), and Spanish moss (Tillandsia usneoides) Two non-native species, Chinaberry (Melia azedarach) and bahiagrass (Paspalum notatum), categorized as invasive by the Georgia Exotic Pest Plant Council (GA-EPPC 2018) were encountered in four different Maritime Upland Forest and Shrubland plots during this monitoring effort. Six vascular plant species listed as rare and tracked by the Georgia Department of Natural Resources (GADNR 2022) were observed in these monitoring plots, including the state listed “Rare” Florida swampprivet (Forestiera segregata var. segregata) and sandywoods sedge (Carex dasycarpa) and the “Unusual” green fly orchid (Epidendrum conopseum). Longleaf and pond pine were the most dominant species within the tree stratum of Coastal Plain Upland Open Woodland habitat types; live oak was the most dominant species of Maritime Upland Forest and Shrubland types. Saw palmetto and rusty staggerbush (Lyonia ferruginea) dominated the sapling stratum within Maritime Upland Forest and Shrubland habitat types. Of the 20 tree-sized redbay trees measured during this monitoring effort only three were living and these were observed with severely declining vigor, indicating the prevalence and recent historical impact of laurel wilt disease (LWD) across the island’s maritime forest ecosystems. There was an unexpectedly low abundance of sweet grass (Muhlenbergia sericea) and saltmeadow cordgrass (Spartina patens) within interdune swale plots of Maritime Open Upland habitats on the island, which could be a result of grazing activity by feral horses. Live oak is the dominant tree-sized species across...
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Sela, Hanan, Eduard Akhunov, and Brian J. Steffenson. Population genomics, linkage disequilibrium and association mapping of stripe rust resistance genes in wild emmer wheat, Triticum turgidum ssp. dicoccoides. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7598170.bard.
Abstract:
The primary goals of this project were: (1) development of a genetically characterized association panel of wild emmer for high resolution analysis of the genetic basis of complex traits; (2) characterization and mapping of genes and QTL for seedling and adult plant resistance to stripe rust in wild emmer populations; (3) characterization of LD patterns along wild emmer chromosomes; (4) elucidation of the multi-locus genetic structure of wild emmer populations and its correlation with geo-climatic variables at the collection sites. Introduction In recent years, Stripe (yellow) rust (Yr) caused by Pucciniastriiformis f. sp. tritici(PST) has become a major threat to wheat crops in many parts of the world. New races have overcome most of the known resistances. It is essential, therefore, that the search for new genes will continue, followed by their mapping by molecular markers and introgression into the elite varieties by marker-assisted selection (MAS). The reservoir of genes for disease and pest resistance in wild emmer wheat (Triticumdicoccoides) is an important resource that must be made available to wheat breeders. The majority of resistance genes that were introgressed so far in cultivated wheat are resistance (R) genes. These genes, though confering near-immunity from the seedling stage, are often overcome by the pathogen in a short period after being deployed over vast production areas. On the other hand, adult-plant resistance (APR) is usually more durable since it is, in many cases, polygenic and confers partial resistance that may put less selective pressure on the pathogen. In this project, we have screened a collection of 480 wild emmer accessions originating from Israel for APR and seedling resistance to PST. Seedling resistance was tested against one Israeli and 3 North American PST isolates. APR was tested on accessions that did not have seedling resistance. The APR screen was conducted in two fields in Israel and in one field in the USA over 3 years for a total of 11 replicates. We have found about 20 accessions that have moderate stripe rust APR with infection type (IT<5), and about 20 additional accessions that have novel seedling resistance (IT<3). We have genotyped the collection using genotyping by sequencing (GBS) and the 90K SNP chip array. GBS yielded a total 341K SNP that were filtered to 150K informative SNP. The 90K assay resulted in 11K informative SNP. We have conducted a genome-wide association scan (GWAS) and found one significant locus on 6BL ( -log p >5). Two novel loci were found for seedling resistance. Further investigation of the 6BL locus and the effect of Yr36 showed that the 6BL locus and the Yr36 have additive effect and that the presence of favorable alleles of both loci results in reduction of 2 grades in the IT score. To identify alleles conferring adaption to extreme climatic conditions, we have associated the patterns of genomic variation in wild emmer with historic climate data from the accessions’ collection sites. The analysis of population stratification revealed four genetically distinct groups of wild emmer accessions coinciding with their geographic distribution. Partitioning of genomic variance showed that geographic location and climate together explain 43% of SNPs among emmer accessions with 19% of SNPs affected by climatic factors. The top three bioclimatic factors driving SNP distribution were temperature seasonality, precipitation seasonality, and isothermality. Association mapping approaches revealed 57 SNPs associated with these bio-climatic variables. Out of 21 unique genomic regions controlling heading date variation, 10 (~50%) overlapped with SNPs showing significant association with at least one of the three bioclimatic variables. This result suggests that a substantial part of the genomic variation associated with local adaptation in wild emmer is driven by selection acting on loci regulating flowering. Conclusions: Wild emmer can serve as a good source for novel APR and seedling R genes for stripe rust resistance. APR for stripe rust is a complex trait conferred by several loci that may have an additive effect. GWAS is feasible in the wild emmer population, however, its detection power is limited. A panel of wild emmer tagged with more than 150K SNP is available for further GWAS of important traits. The insights gained by the bioclimatic-gentic associations should be taken into consideration when planning conservation strategies.
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Cohen, Yuval, Christopher A. Cullis, and Uri Lavi. Molecular Analyses of Soma-clonal Variation in Date Palm and Banana for Early Identification and Control of Off-types Generation. United States Department of Agriculture, October 2010. http://dx.doi.org/10.32747/2010.7592124.bard.
Abstract:
Date palm (Phoenix dactylifera L.) is the major fruit tree grown in arid areas in the Middle East and North Africa. In the last century, dates were introduced to new regions including the USA. Date palms are traditionally propagated through offshoots. Expansion of modern date palm groves led to the development of Tissue Culture propagation methods that generate a large number of homogenous plants, have no seasonal effect on plant source and provide tools to fight the expansion of date pests and diseases. The disadvantage of this procedure is the occurrence of off-type trees which differ from the original cultivar. In the present project we focused on two of the most common date palm off-types: (1) trees with reduced fruit setting, in which most of the flowers turn into three-carpel parthenocarpic fruits. In a severe form, multi-carpel flowers and fruitlets (with up to six or eight carpels instead of the normal three-carpel flowers) are also formed. (2) dwarf trees, having fewer and shorter leaves, very short trunk and are not bearing fruits at their expected age, compared to the normal trees. Similar off-types occur in other crop species propagated by tissue culture, like banana (mainly dwarf plants) or oil palm (with a common 'Mantled' phenotype with reduced fruit setting and occurrence of supernumerary carpels). Some off-types can only be detected several years after planting in the fields. Therefore, efficient methods for prevention of the generation of off-types, as well as methods for their detection and early removal, are required for date palms, as well as for other tissue culture propagated crops. This research is aimed at the understanding of the mechanisms by which off-types are generated, and developing markers for their early identification. Several molecular and genomic approaches were applied. Using Methylation Sensitive AFLP and bisulfite sequencing, we detected changes in DNA methylation patterns occurring in off-types. We isolated and compared the sequence and expression of candidate genes, genes related to vegetative growth and dwarfism and genes related to flower development. While no sequence variation were detected, changes in gene expression, associated with the severity of the "fruit set" phenotype were detected in two genes - PdDEF (Ortholog of rice SPW1, and AP3 B type MADS box gene), and PdDIF (a defensin gene, highly homologous to the oil palm gene EGAD). We applied transcriptomic analyses, using high throughput sequencing, to identify genes differentially expressed in the "palm heart" (the apical meristem and the region of embryonic leaves) of dwarf vs. normal trees. Among the differentially expressed genes we identified genes related to hormonal biosynthesis, perception and regulation, genes related to cell expansion, and genes related to DNA methylation. Using Representation Difference Analyses, we detected changes in the genomes of off-type trees, mainly chloroplast-derived sequences that were incorporated in the nuclear genome and sequences of transposable elements. Sequences previously identified as differing between normal and off-type trees of oil palms or banana, successfully identified variation among date palm off-types, suggesting that these represent highly labile regions of monocot genomes. The data indicate that the date palm genome, similarly to genomes of other monocot crops as oil palm and banana, is quite unstable when cells pass through a cycle of tissue culture and regeneration. Changes in DNA sequences, translocation of DNA fragments and alteration of methylation patterns occur. Consequently, patterns of gene expression are changed, resulting in abnormal phenotypes. The data can be useful for future development of tools for early identification of off-type as well as for better understanding the phenomenon of somaclonal variation during propagation in vitro.
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A 40-Year Retrospective of APHIS, 1972–2012. United States Department of Agriculture, Animal and Plant Health Inspection Service, January 2012. http://dx.doi.org/10.32747/2012.7204068.aphis.
Abstract:
Since APHIS was formed in 1972, it has evolved into a multi-faceted Agency with responsibilities that include protecting and promoting U.S. agricultural health from foreign pests and diseases, regulating genetically engineered organisms, administering the Animal Welfare Act, and carrying out wildlife damage management activities. It has been 15 years since APHIS compiled a history of its mission and activities. This year, 2012, marks both the 40th anniversary of the Agency and the 150th anniversary of USDA, providing a unique opportunity to put that history in context. This retrospective briefly examines the history of animal and plant health regulation within USDA, assesses APHIS'
development over four decades, includes biographies of the Agency’s Administrators, and provides snapshots of some of the milestone issues and events that define the Agency’s history and its accomplishments.