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Omar, Ibrahim. "Biological control of crown and root rot of tomato." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310952.
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El, Masry Mousa Ahmed. "Biological and chemical control of Pythium butleri on tomato." Thesis, University of London, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265901.
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Sivananthan, Malini. "An examination of the relationship between NO, ABA and auxin in lateral root initiation and root elongation in tomato." Thesis, University of Canterbury. Biological Sciences, 2006. http://hdl.handle.net/10092/1375.
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The length of the primary root and the density of lateral roots determine the architecture of the root. In this thesis the effect of NAA, ABA and the NO donor SNP alone as well as the combination of ABA or NAA with SNP on lateral root development was investigated. The interaction between CPTIO, a NO scavenger, and NAA or SNP is also reported. Following preliminary experiments in which it was observed that the aerial part of the seedling influenced LR growth and that there was a possible inhibitory effect of light on cultured root tips, experiments were conducted with excised roots tips in the dark. NAA was shown to have the potential to initiate LRs across a wide concentration gradient with the total number of LRs and initiated lateral root primordia (LRP) remaining constant across the range of concentrations tested. Over the last decade, nitric oxide (NO), a bioactive molecule, has been reported to be involved in the regulation of many biological pathways. The presence of NO in the system provided via sodium nitroprusside (SNP), promoted LRP initiation based on the NAA concentration gradient; but without changing the total LR initiation, that is LRs plus primordia density remained constant along the concentration gradient of NAA. The absence of LR and LRP in the treatments of CPTIO (a NO scavenger) with SNP or NAA suggests that NO regulates LRP initiation triggered by NAA, which is in agreement with the recent paper published after the commencement of this study (Correa-Aragunde et al., 2006). In agreement with previous studies, ABA inhibited lateral root development by reducing LR density and the number of LRs. The experiments with fluridone, an ABA biosynthesis inhibitor, may indicate that endogenous ABA was at sufficient concentrations in the excised root tips to inhibit primordia initiation. In this study, evidence is presented for the first time to show that SNP can relieve the inhibitory effect of ABA on LR density and number of LRs suggesting the NO, released from SNP, acts downstream of ABA. Overall these data confirm a critical role for NO in LR initiation.
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Mansoorkhani, Fereshteh Malekpoor. "Investigating the genetic and molecular basis of root architecture in tomato." Thesis, University of Nottingham, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.718989.
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Root system architecture (RSA) and morphology are important for plant productivity as many soil resources are unevenly distributed. RSA varies widely between species, individuals in a species and even within individual root systems. In recent years, the structure and function of plant root systems has received increasing attention. Many cultivated plants have undergone a reduction in genetic variability from ancestral forms, and this is particularly obvious in tomato whose history of domestication has significantly reduced the variation available in the cultivated tomato gene pool. However, substantial variation for root architecture and other traits still exists in related wild Solanum species. This root variability can be potentially used to breed new and improved tomato varieties. Quantitative Trait Loci (QTL) for root architecture and other important traits can be identified using available sets of tomato introgression lines, which were developed through a succession of backcrosses. The small green-fruited species Solanum pennellii is a distant sexually compatible relative of S. lycopersicum (domesticated tomato) native to the Andes mountains of South America. S. pennelli was used as a founding donor parent of the first tomato introgression (IL) population made available for interspecific QTL identification, cloning, and plant breeding. In this project, the S. pennellii IL population was used as the starting point to fine map QTL involved in the control of tomato root architecture. A large effect QTL was identified on the top of tomato chromosome 4. The QTL region enhanced root length and number of lateral roots. To fine map the underlying gene(s), approximately 8000 IL 4-1-1 F2 plants were screened to identify recombinants, leading to the generation of two small ILs (Q1120 and Q2173) harbouring the root system architecture (RSA) QTL. These recombinants delineated a mapping interval of 177kb containing 26 gene models. Analysis of the genes in the mapping interval indicated that several showed expression depending on the presence of an M82 or S.pennellii allele. Based on these and other criteria two genes were selected as RSA QTL candidates. These included a transcription factor belonging to the bHLH class and the gibberellin receptor GID1. Functional studies in Arabidopsis and tomato are in progress to validate the link between these genes and improved RSA.
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MacLeod, Michael M. "Control of Fusarium crown and root rot on tomato seedlings using synthetic iron chelators and phenolic compounds found in lettuce roots." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq21095.pdf.
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Alwan, A. H. "The influence of root solution environment on fruit production by tomato plant." Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355895.
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Malatji, Kgashane Philip. "Development of mean concentration stimulation point for fermented Lantana Camara Phytonematicide on tomato production." Thesis, University of Limpopo, 2017. http://hdl.handle.net/10386/1918.
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Thesis (M.Sc. (Agriculture)) --University of Limpopo, 2017Root-knot nematodes (Meloidogyne species) are the major soil-borne pests of tomato (Solanum lycorpesicum) plants. Due to the global withdrawal of effective chemical nematicides from the agrochemical markets, nematodes are difficult to control under the production systems. Currently, botanicals are being researched and developed as alternative to chemical nematicides with promising results, although they have challenge of phytotoxicity. The objective of this study was to determine the Mean Concentration Stimulation Point (MCSP) of Tickberry (Lantana camara) extracts for tomato plant-infected with M. javanica. Treatments consisted of six levels of L. camara extracts, namely, 0, 2, 4, 6, 8 and 10% per pot, which were arranged in a randomised complete block design, with ten replicates. Tomato seedlings were inoculated with 2500 second-stage juveniles (J2S) of M. javanica at five days after transplanting, with treatments applied at seven days after inoculation. At 56 days after inoculation, L. camara extracts had positive effects on plant height, stem diameter, number of leaves, number of fruits and fruit mass, contributing 65, 74, 61, 25 and 61% in total treatment variation (TTV), respectively, under greenhouse conditions. Under microplot conditions, treatments contributed 55, 85, 61, 36 and 85% in TTV of the respective plant variables. Under greenhouse it contributed 60, 35 and 77% and 29, 79 and 70% under microplot on dry shoot mass, dry root mass and galling index respectively. Treatments did not have any effects on soil pH and electrical conductivity (EC). Under greenhouse conditions, treatments contributed 88, 94 and 92% in TTV of nematode in roots, soil and final population, respectively, whereas under microplot conditions 94, 97 and 95% in xvii TTV of the respective nematode stages. The derived mean concentration of L. camara extracts for tomato was 5.76 and 5.31% under microplot and greenhouse conditions, respectively. The overall sensitivity of tomato plants to L. camara extracts under microplot and greenhouse were 3 and 0, respectively. In conclusion Meloidogyne species can be managed using L. camara extracts 5.31 and 5.76% under glasshouse production and field production system respectively.
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Hasna, Mahbuba Kaniz. "Corky root disease management in organic tomato production : composts, fungivorous nematodes and grower participation /." Uppsala : Dept. of Crop Production Ecology, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/2007114.pdf.
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Karanja, Daniel Kimani. "Studies on integrated management of root-knot nematodes (Meloidogyne spp.) on tomato in Kenya." Thesis, University of Reading, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408105.
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Bingham, I. J. "Effects of root-zone temperature on the growth, water and mineral relations of tomato (Lycopersicon esculentum Mill.)." Thesis, Oxford Brookes University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355125.
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Smith, Caroline Louise. "Biological control of root-knot nematodes (Meloidogyne spp.) with Pasteuria penetrans and Verticillium chlamydosporium in Costa Rica." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297317.
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Neophytou, Georgios. "Studies on integrated control programmes for root-knot nematodes (Meloidogyne Spp.) on tomato in Cyprus." Thesis, Imperial College London, 2004. http://hdl.handle.net/10044/1/7521.
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Ayling, Sarah Marian. "The role of calcium in the cytoplasmic streaming response of tomato root hairs to auxin." Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386178.
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Kashyap, Anurag. "Ralstonia solanacearum-triggered defense responses at the tomato root xylem vasculature: Insights on the suberin pathway." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/672532.
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Ralstonia solanacearum és un dels patògens bacterians de plantes més devastadors del món. Aquest bacteri és l’agent causant del marciment bacterià en més de 450 espècies de plantes i causa una devastació severa en cultius de solanàcies com la tomaquera. R. solanacearum accedeix a sistema radicular a través de ferides i llocs d’emergència d’arrels laterals i després es desplaça fins a la vasculatura radicular, on es multiplica al xilema i després es dissemina verticalment a través del xilema i horitzontalment entre els vasos i els teixits circumdants. Fins ara, l’estratègia de maneig més fiable per controlar R. solanacearum ha estat l’ús de resistència genètica. En tomàquet, entre les millors fonts de resistència es troba el conrear resistent Hawaii 7996 (H7996), que s’usa comunament com a patró en el cultiu comercial de tomàquet. Aquesta varietat resistent ha desenvolupat mecanismes de defensa efectius per prevenir la colonització de vasos o el moviment entre vasos un cop que ha passat la colonització vascular.
Publicacions recents mostren que el cilindre vascular del xilema de l’arrel actua com a teixit predominant per muntar una resposta de defensa eficaç contra els invasors vasculars, restringint l’avanç del patogen cap al teixit aeri. No obstant això, els mecanismes que regulen aquesta forma de resistència segueixen sent desconeguts en gran manera. Desentranyar els mecanismes a través dels quals les plantes bloquegen o alenteixen la progressió de patògens en la vasculatura del xilema de l’arrel pot ser vital en el desenvolupament de varietats resistents mitjançant intervencions biotecnològiques. Per tant, en aquesta tesi intentem aprofundir en les respostes de defensa que actuen en la vasculatura del xilema de l’arrel que restringeixen efectivament la colonització pel patogen bacterià vascular R. solanacerum en tomàquet.
Els estudis histopatològics comparatius en línies de tomàquet resistents i susceptibles indiquen que un reforç vascular compost de ferulats, que culmina en la formació d’una zona ferulo-suberínica que pot actuar com una forta barrera fisico-química contra la invasió de R. solanacearum (Capítol 1). Aquesta barrera fenòlic-alifàtica reforça les parets del teixit vascular del xilema en H7996 i pot restringir el moviment del bacteri des de l’interior del vas del xilema cap al xilema circumdant, cèl·lules de l’parènquima, vasos propers i espais intercel·lulars. Els canvis de composició en les parets es van estudiar mitjançant espectroscòpia, la qual cosa va mostrar una intensa acumulació de metabòlits compatibles amb la suberina específicament en les arrels de H7996 resistent, després de la infecció de R. solanacearum (Capítol 2). Es van observar diferències en l’estat de polimerització de la lignina en les arrels després de la infecció entre tomàquet resistent i susceptible. L’H7996 contenia una major proporció de lignina de tipus G, que és més resistent a la degradació, mentre que Marmande susceptible contenia més lignina de tipus S, que és més propensa a degradar-se. L’expressió de gens de la via biosintètica d’àcids grassos de la suberina es va incrementar significativament en el teixit vascular de l’xilema de l’arrel primària de les plantes infectades amb H7996 en comparació amb els controls o el tomàquet susceptible (Capítol 3). Això indica que la regulació positiva d’aquests gens és una resposta específica de plantes H7996 resistents que té lloc a la vasculatura suberizada després de la infecció per R. solanacearum. A més, es va observar inducció de ProSlFHT::GUS en la vasculatura del xilema de l’arrel principal de les plantes H7996 infectades, així com en teixits que se sap que dipositen suberina com ara epidermis, exodermis i teixits que experimenten cicatrització de ferides.Ralstonia solanacearum es uno de los patógenos bacterianos de plantas más devastadores del mundo. Esta bacteria del suelo es el agente causante de la marchitez bacteriana en más de 450 especies de plantas y causa una devastación severa en cultivos de solanáceas como el tomate. R. solanacearum accede al sistema radicular a través de heridas y sitios de emergencia de raíces laterales y luego se desplaza hasta la vasculatura radicular, donde se multiplica en el xilema y luego se disemina verticalmente a través del xilema y horizontalmente entre los vasos y los tejidos circundantes. Hasta la fecha, la estrategia de manejo más fiable para controlar R. solanacearum ha sido el uso de resistencia genética. En tomate, entre las mejores fuentes de resistencia se encuentra el cultivar resistente Hawaii 7996 (H7996), que se usa comúnmente como patrón en el cultivo comercial de tomate. Este cultivar resistente ha desarrollado mecanismos de defensa efectivos para prevenir la colonización de vasos o el movimiento entre vasos una vez que ha ocurrido la colonización vascular. Publicaciones recientes muestran que el cilindro vascular del xilema de la raíz actúa como tejido predominante para montar una respuesta de defensa eficaz contra los invasores vasculares, lo que restringe el avance del patógeno hacia el tejido aéreo. Sin embargo, los mecanismos que regulan esta forma de resistencia siguen siendo desconocidos en gran manera. Desentrañar los mecanismos a través de los cuales las plantas bloquean o ralentizan la progresión de patógenos en la vasculatura del xilema de la raíz puede ser vital en el desarrollo de cultivares resistentes mediante intervenciones biotecnológicas. Por lo tanto, en esta tesis intentamos arrojar luz sobre las respuestas de defensa que actúan en la vasculatura del xilema de la raíz que restringen efectivamente la colonización por el patógeno bacteriano vascular R. solanacerum en tomate. Los estudios histopatológicos comparativos en líneas de tomate resistentes y susceptibles indican que un refuerzo vascular compuesto de ferulatos, que culmina en la formación de una zona ferulo-suberínica, puede actuar como una fuerte barrera físico-química contra la invasión de R. solanacearum (Capítulo 1). Esta barrera fenólico-alifática refuerza las paredes del tejido vascular del xilema en H7996 y puede restringir el movimiento de la bacteria desde la luz del vaso del xilema hacia el xilema circundante, células del parénquima, vasos cercanos y espacios intercelulares. Los cambios de composición en las paredes se estudiaron mediante espectroscopia, lo cual mostró una intensa acumulación de metabolitos compatibles con la suberina específicamente en las raíces de H7996 resistente, tras la infección de R. solanacearum (Capítulo 2). Se observaron diferencias en el estado de polimerización de la lignina en las raíces después de la infección entre tomate resistente y susceptible. El H7996 contenía una mayor proporción de lignina de tipo G, que es más resistente a la degradación, mientras que Marmande susceptible contenía más lignina de tipo S, que es más propensa a degradarse. La expresión de genes de la vía biosintética de ácidos grasos de la suberina se incrementó significativamente en el tejido vascular del xilema de la raíz primaria de las plantas infectadas con H7996 en comparación con los controles o el tomate susceptible (Capítulo 3). Esto indica que la regulación positiva de estos genes es una respuesta específica de plantas H7996 resistentes que tiene lugar en la vasculatura suberizada tras la infección por R. solanacearum. Además, se observó inducción de ProSlFHT::GUS en la vasculatura del xilema de la raíz principal de las plantas H7996 infectadas, así como en tejidos que se sabe que depositan suberina tales como epidermis, exodermis y tejidos que experimentan cicatrización de heridas.
Ralstonia solanacearum is one of the world's most devastating bacterial pathogens of plants. This soil-borne bacterium is the causative agent of bacterial wilt on more than 450 plant species, and it causes severe devastation on Solanaceous crops like tomato. R. solanacearum gains access to the root system through wounds and lateral root emerging sites and then moves to the root vasculature, where it multiplies in the xylem and later spreads vertically within the xylem sap and horizontally between vessels and to the surrounding tissues. To date, the most reliable management strategy to control R. solanacearum has been the use of genetic resistance. In tomato, among the best resistance sources is the resistant cultivar Hawaii 7996 (H7996), which is commonly used as a rootstock in commercial tomato cultivation. This resistant cultivar has evolved effective defense mechanisms to prevent vessel colonization or movement between vessels once vascular colonization has occurred. Recent reports show that the root xylem vascular cylinder acts as a predominant tissue for mounting an efficient defense response against vascular invaders, restricting onward movement of the pathogen to the aerial tissue. However, the mechanisms regulating this form of resistance remain elusive. Unravelling the mechanisms through which the plants block or slow down pathogen progression at the root xylem vasculature can be vital in the development of resistant cultivars by biotechnological interventions. Hence, in this thesis we attempted to shed light on the defense responses acting at the root xylem vasculature that effectively restrict colonization by the vascular bacterial pathogen R. solanacerum in tomato. Comparative histopathological studies in resistant and susceptible tomato lines indicated that a ferulate vascular reinforcement, culminating into a ferulo-suberin zone, may act as a strong physico-chemical barrier against R. solanacearum invasion (Chapter 1). This phenolic- aliphatic barrier reinforces the walls of xylem vascular tissue in H7996 and may restrict movement of the bacterium from the xylem vessel lumen to the surrounding xylem parenchyma cells and nearby vessels and inter-cellular spaces. Compositional changes in walls were studied using spectroscopy, which showed strong accumulation of suberin- compatible metabolites specifically in roots of resistant H7996, upon infection of R. solanacearum (Chapter 2). Differences in the polymerization state of lignin in roots were observed after infection between resistant and susceptible tomato. H7996 contained a higher proportion of G-type lignin, which is more resistant to degradation, whereas susceptible Marmande contained more S-type lignin, which is more prone to degradation. Expression of genes from the suberin fatty acid biosynthetic pathway was significantly upregulated in the taproot xylem vascular tissue of H7996 infected plants compared to the mock controls or susceptible tomato (Chapter 3). This indicates that upregulation of these genes is a specific response of resistant H7996 plants that takes place in suberizing vasculature upon R. solanacearum infection. Further, induction of ProSlFHT::GUS was observed in taproot xylem vasculature of infected H7996 plants, as well as in tissues known to deposit suberin such as epidermis, exodermis and tissues undergoing wound healing. Implications of overexpressing genes from pathway of suberin and the associated soluble phenolics synthesis, were evaluated in susceptible tomato background. Overexpression of suberin feruloyl transferase (FHT), which catalyzes the formation feruloyl esters showed limited restriction against R. solanacearum. In contrast, overexpression of tyramine N-hydroxycinnamoyltransferase (THT 1-3), responsible for synthesis of hydroxycinnamic acid amides (HCAA) such as feruloyl tyramine resulted in an increase of resistance against R. solanacearum with disease progressing remarkably slower in this line compared to wild type plants. Accumulation of such aminated phenolics may act as a chemical barrier acting as phytoalexin but could also act as physical barrier if cross-linked to the poly-aromatic domain of suberin.
Universitat Autònoma de Barcelona. Programa de Doctorat en Biologia i Biotecnologia Vegetal
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Escudero, Benito Nuria. "Rhizomodulation for tomato growth promotion and management of root knot nematodes using Pochonia chlamydosporia and chitosan." Doctoral thesis, Universidad de Alicante, 2015. http://hdl.handle.net/10045/63467.
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Smith, Linley Joy. "Intercropping with resistant cultivars reduces early blight and root knot disease on susceptible cultivars of tomato (Lycopersicon esculentum)." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2592.
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Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains viii, 77 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 71-77).
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González, Hernández Ana Isabel. "New approaches to control Pseudomonas syringae disease in tomato plants." Doctoral thesis, Universitat Jaume I, 2019. http://hdl.handle.net/10803/666683.
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Las plagas y enfermedades son factores a tener en cuenta ya que producen elevadas pérdidas en la producción de los cultivos. Actualmente, la búsqueda de compuestos no perjudiciales para el medioambiente y que sean capaces de inducir los mecanismos de defensa en las plantas frente a estreses es un tema prioritario. Por ello, el objetivo de esta tesis ha sido estudiar el mecanismo de inducción de defensa de los compuestos heptagluconato de cobre, 1-metiltriptófano (1-MT) y amonio, en el patosistema tomate-P. syringae. De forma general, el heptagluconato de cobre induce compuestos fenólicos, el 1-MT induce el cierre estomático y afecta al contenido del apoplasto y a la motilidad de la bacteria y, el amonio produce una reprogramación del metabolismo primario. Además, se ha estudiado como se modifica la arquitectura radicular bajo distintas fuentes de N y C, observando que la adición de nitrato o compuestos carbonados al tratamiento con amonio alivia la toxicidad causada por éste.Pests and diseases are important factors to take into account in order to avoid losses in crop production. Nowadays, the search of new enviro-friendly compounds to induce defence mechanisms in plants to fight against plant diseases is a priority. Thus, the goal of this thesis has been to study the action mode of the enviro-friendly inducers of resistance copper-heptagluconate, 1-methyltryptophan (1-MT) and ammonium in tomato-P. syringae pathosystem. In general terms, Cu-heptagluconate induces phenolic compounds, 1-MT induces stomatal closure and affects apoplastic content and bacterial motility, and ammonium nutrition produces a primary metabolism reprogramming. Moreover, the study of changes at root level under nitrate and ammonium sources has been carried out, showing that the addition of nitrate or C compounds to ammonium treatment alleviates its mild toxicity.
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Khalil, Sammar. "Microflora in the root environment of hydroponically grown tomato : methods for assessment and effects of introduced bacteria and Pythium ultimum /." Alnarp : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-5787-4.pdf.
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Ehsanpour, Ali Akbar. "Cell biological manipulations for transfer of the Mi root-knot nematode resistance gene from tomato to potato." Thesis, Ehsanpour, Ali Akbar (1995) Cell biological manipulations for transfer of the Mi root-knot nematode resistance gene from tomato to potato. PhD thesis, Murdoch University, 1995. https://researchrepository.murdoch.edu.au/id/eprint/41580/.
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Improvement of potato (Solanum tuberosum), an important crop for food consumption and biomass has until recently been confined to conventional breeding approaches. Root-knot nematodes (Meloidogyne spp) are serious pests of crop and horticultural plants, including potato, in tropical and sub-tropical regions of the world. The Mi resistance gene derived from Lycopersicon peruvianum has been introduced into cultivated tomato. This gene confers resistance to three major species of root-knot nematodes. Tomato lines containing the Mi gene have been obtained and were tested for functional resistance to root-knot nematodes by infection with nematode juveniles in glasshouse tests. The presence of the Mi gene in resistant tomato lines was also confirmed using two biochemical methods: (1) by staining of specific bands on polyacrylamide gels (PAGE) for an acid phosphatase-I I enzyme linked to the Mi gene, and (2) the presence of an amplified DNA fragment of 570 hp using specific PCR primers (REX-Fl and REX-F2) which amplify a DNA sequence closely linked to the Mi gene. For tissue culture experiments, potato and tomato shoot cultures were established, and larger potato leaves were induced by treatment with silver thiosulfate (STS) to inhibit ethylene production. Potato and tomato protoplasts were isolated from these shoots and a protoplast-to-plant regeneration system for potato cv. Delaware was established. Conditions required to induce electrofusion between potato and tomato protoplasts were optimised. However, the Mi resistant tomato genotypes were not responsive in culture, and hybrid plants were not generated. As a result, procedures for direct gene transfer of the Mi gene were studied. Optimum conditions for direct gene transfer ( electroporation) of potato cv. Delaware were established and calli were obtained from Delaware protoplasts after electroporation with tomato DNA (line BTN815). These were analysed by PCR. To improve the frequency of transformants that might contain Mi DNA, DNA enriched with low copy repetitive sequences was obtained by passage through a hydroxyapatite column. This work forms the basis for further experiments to transfer DNA fragments, which include the Mi gene, into potato by direct gene transfer. In further cell biological studies, transgenic plants containing a Parasponia promoter-glucuronidase insert were analysed for expression of the reporter gene when infected with root-knot nematodes. The reporter gene was down-regulated in early stages of giant cell development, but strongly up-regulated in mature giant cells.
The results of the research were discussed in relation to various options available to introduce resistance to root-knot nematodes into potato, using cell biological transfer or genetic engineering of natural or synthetic resistance genes.
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Tabil, Magnus Amos. "Studies on the use of Xenorhabdus spp. for the management of root-knot nematode (Meloidogyne javanica) on tomato." Thesis, University of Reading, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487485.
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The effect of cells and toxins of Xenorhabdus spp. as biological .control on root-knot nematode (Meloidogyne javanica) was investigated. The mutualist b~cteria were obtained from two entomopathogenic nematodes, Steinemema abbasi and S. riobrave originating from the United Arab Emirates and were identified to the genus level using molecular techniques and the partial 16S rRNA gene sequences were deposited with the GENBANK. The bacteria were given Accession numbers as 00186672 for Xenorhabdus sp. RUAE (fro':l Steinemema abbasl) and 00186671, 00186674 and 00186673 for Xenorhabdus sp. 119, Xenorhabdus sp.120 and Xenorhabdus sp.124 from and S. riobrave. 00186672 was closely related to X. japonica and X. nematophila while the other three were found to be same species having 100% gene sequence homology. Cells and toxins of X. bovienii, X. nematophila and Xenorhabdus sp. RUAE (00186672) proved nematoxic to M. javanica. Higher concentrations of cells and toxins were more effective in immobilisation of juveniles and suppression of hatching of eggs than the lower concentrations. At 25°C, X. nematophila inhibited more egg hatch than ?. bovienii. The four newly isolated Xenorhabdus spp. equally inhibited egg' hatch and immobilised J2. At concentration of 2x1 07 cells/ml, X. nematophila, Xenorhabdus sp. 119 (00186671) and Xenorhabdus sp.120 (00186674) completely prevented egg hatch. Cell suspensions of all the Xenorhabdus spp. used caused more than 80-90% immobilisation of juveniles. On phytotoxicity, 30min exposure of roots of tomato seedlings recorded the highest survival at concentrations of 2x107 and 4x107cells/ml. X. nematophila and Xenorhabdus sp. RUAE (00186672) when stored in compost soil for 2 months caused over 60% mortality of larvae of Gallaria mellonella. When the same bacteria were stored in sealed bottles either in a fridge (at 5°C) or on the laboratory bench for one year recorded over 60% immobilisation of juveniles of M. incognita. When used as a soil drench, all the bacteria reduced penetration of roots and production of eggs. Similar results were obtained when tomato plants were treated with bacteria as bare-root dip for 30 min. When the bacteria were applied as bare-root dip for the tomato seedlings and transplanted into soil naturally-infested with root-knot nematode, the suppression of penetration and egg formation was less effective.
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Leontopoulos, Stefanos. "Evaluating the efficacy of the bacterium Pseudomonas oryzihabitans against the root-knot nematode Meloidogyne javanica on the tomato." Thesis, University of Reading, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428316.
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Bosques, Martínez Marlia. "Assessment of Root-Knot Nematode Presence in Tomatoes in Ohio, Yield Loss, and Biocontrol." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1577534641175364.
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Gomes, Ana Maria Figueira. "Interações hormonais no crescimento de raízes de tomateiro (Solanum Lycopersicum L. cv Micro-Tom) sob estresse osmótico." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/11/11144/tde-12092011-151109/.
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O tomateiro (Solanum lycopersicum) tornou-se importante ferramenta para estudos de genética e fisiologia nos últimos anos, devido à disponibilidade de mutantes, incluindo aqueles com alterações hormonais. Nesta cultura, a cultivar ornamental miniatura de tomateiro Micro-Tom (MT) tem sido utilizada como modelo genético em vários estudos, visto que produz frutos e sementes viáveis em vasos de apenas 50-100 ml de substrato, completando o ciclo em setenta a noventa dias. Este trabalho foi feito com o intuito de gerar informações que possam colaborar para a compreensão dos mecanismos que determinam a sensibilidade das raízes ao estresse hídrico. Para tal, foram criados duplos mutantes hormonais homozigóticos da cultivar MT, sendo posteriormente usados para verificar o papel das interações hormonais ABA-Etileno no controle do crescimento da raiz sob condições de estresse osmótico. O estudo é relevante pelo fato de que o entendimento dos mecanismos de controle hormonal no crescimento radicular poderá auxiliar a pesquisa de melhoramento genético para a obtenção de plantas tolerantes à seca, o que representaria avanço na agricultura, principalmente para regiões de clima árido e semiárido. Os experimentos foram realizados no Laboratório de Controle Hormonal do Desenvolvimento Vegetal da ESALQ-USP, onde foram produzidos genótipos de cinco duplos mutantes: diagetropica/sitiens (dgt/sit), diagetropica/epinastic (dgt/epi), diagetropica/Never ripe (dgt/Nr), sitiens/epinastic (sit/epi) e Never ripe/sitiens (Nr/epi) em homozigose em BC6Fn. Sementes germinadas de (MT) e de mutantes de sitiens (sit), Never ripe (Nr) e o duplo mutante Nrsit foram colocadas em tratamento com PEG 6000 em diferentes potenciais osmóticos. Também foram realizados experimentos com ácido cloro-2-etil fosfônico (CEPA), um liberador de etileno (Ethrel), e o inibidor da síntese do mesmo, o aminoetoxivinil glicina (AVG), sendo avaliados os parâmetros como crescimento radicular, caulinar, razão raiz/hipocótilo e conteúdo relativo de água (CRA). Observouse que baixos potencias osmóticos inibem mais o caule que a raiz, e que o estresse osmótico moderado (-0.6 MPa) favoreceu o crescimento da raiz e da razão raiz/hipocótilo em MT, principalmente em sit e, em menor extensão, na raiz de Nr/sit. Esse crescimento não foi observado em Nr. No mutante sit, em -1.1 MPa, observou-se inchaço radicular semelhante ao provocado pela presença de etileno. Em menor extensão, esse inchaço também foi observado no duplo mutante Nr/sit. Quando adicionado Ethrel, houve inibição do crescimento radicular em sit e MT, sendo também observado um pouco de inibição no mutante insensível a etileno, Nr. Em estresse moderado (-0.6 MPa), a inibição foi mais severa do que em água para MT, mas não para sit, até a dose de 1 µM. A inibição do etileno causada pelo AVG resultou em uma maior diferença entre água e -0.6 MPa, sendo o último mais inibido. Pode-se concluir que, em condições de déficit hídrico moderado, há aumento radicular e da razão/hipocótilo quando comparados a condições normais de suprimento de água. Tais constatações são importantes porque podem ajudar no desenho de práticas agronômicas que podem levar a maior economia de água, bem como aumento da eficiência de uso de água pelas plantas.Tomato (Solanum lycopersicum) has become a very important model for genetic and physiological studies in the last years, due to the presence of various mutants, including those with hormonal alterations. The ornamental dwarf tomato cv. Micro-Tom (MT) has been largely used because of its ability to produce viable fruits and seeds in pots of just 50-100 ml, completing its life cycle in seventy to ninety days. In an attempt to gain insights on the mechanisms that regulate plant growth under physiologic stress, homozygote hormonal double mutants of the MT were created and later on screened for the role of hormonal interactions in the control of root growth under osmotic stress. The experiment was conducted at ESALQ-USP Hormonal Control of Plant Development Laboratory, where genotypes of five double mutants namely diagetropica/sitiens (dgt/sit), diagetropica/epinastic (dgt/epi), diagetropica/Never ripe (dgt/Nr), sitiens/epinastic (sit/epi) and Never ripe/sitiens (Nr/epi) were produced in BC6Fn homozygosis. Germinated seeds of MT and the mutants sitiens (sit), Never ripe (Nr) and the double mutant Nr/sit were treated with PEG 6000 at different osmotic potentials. There were also experiments with chloro-2-ethyl phosphonic acid (CEPA), an ethylenereleaser (Ethrel) and the inhibitor of ethylene synthesis aminoethyoxyvinyl glycine (AVG). The parameters evaluated were radicle and hypocotyls growth, root/hypocotyl ratio and relative water content (RWC). The stem was more inhibited than the root at moderate osmotic stress (-0.6 MPa), which resulted in elevated root/hypocotyl ratio for MT, sit and, in lesser extent, Nr/sit. This pattern was not observed in Nr. A root swelling similar to that caused by ethylene was observed in sit at -1.1 MPa. This swelling was less evident in the double mutant Nr/sit. When added Ethrel, there was inhibition of root growth in sit and MT. A discrete root inhibition was also observed in the ethyleneinsensitive Nr mutant. In moderate osmotic stress (-0.6 MPa), root inhibition was more severe than in water for MT, but not for sit, until 1 µM Ethrel. The AVG application increased this difference between water and PEG 6000 treatments. It can be concluded that, in moderate water deficit, the root growth and root/hypocotyl ratio were increased, when compared to normal water supply. These findings are important, since they can provide for the better design of agronomic practices and crop improvement aiming at the enhancement of water use efficiency.
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Pitelli, Angelica Maria de Campos Machado. "Controle hormonal do crescimento de raízes de tomateiro (Lycopersicon esculentum cv. Micro-Tom) em condições de déficit hídrico." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-05042006-163611/.
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A deficencia hídrica é o principal fator de estresse para o crescimento vegetal. Dentre os mecanismos de resistência à seca tem-se a resposta de crescimento radicular sob condições de déficit hídrico. Esta resposta assume-se ser regulada por hormônios vegetais. Uma abordagem interessante para o estudo de processos regulados por hormônios é a utilização de mutantes hormonais em um modelo genético. O tomateiro cv. Micro-Tom por seu porte reduzido e ciclo de vida curto constitui em bom modelo genético. Mutantes hormonais em tomateiro com baixo nível endógeno de ABA (sit, flacca), insensível a etileno (Nr), com superprodução de etileno (epi) e insensível à auxina (dgt) constituem-se valiosas ferramentas para o estudo da ação hormonal na regulação de processos fisiológicos. O presente trabalho teve como objetivo estudar a interação hormonal na regulação do processo de crescimento radicular em condições de déficit hídrico no cultivar Micro-Tom de tomateiro. Sementes germinadas de MT e dos mutantes sit, dgt, epi, e Nr foram colocadas em caixas Gerbox pretas contendo água e soluções de PEG apresentando potenciais de 0,3; -0,6; -0,9; -1,2 MPa. Após cinco dias foi avaliado o comprimento da raiz e do hipocótilo. Também foram realizados experimentos com sementes de MT e dos mutantes em Gerbox contendo inibidores da biossíntese de ABA (fluridone), da ação do etileno, o tiossulfato de prata (STS) e um liberador desse mesmo hormônio, o ácido 2-cloro-etil-fosofonico (CEPA) em água e em solução de PEG com potencial osmótico de 0,6 MPa. O comprimento das raízes foi avaliado após cinco dias. O potencial osmótico de 0,6 MPa favoreceu o crescimento radicular nos genótipos MT, dgt e epi e em menor grau em Nr. Esse crescimento não ocorreu nos genótipos sit. No mutante sit há um inchaço semelhante ao provocado por excesso de etileno. Quando foi adicionado o CEPA (etileno), houve inibição severa do crescimento radicular em água em MT e em sit. A inibição foi menor em dgt. Em potencial de -0,6 MPa a inibição foi mais severa do que em água no MT. A inibição do etileno provocada pelo STS, causou uma maior diferença entre o crescimento em água e no potencial de -0,6 MPa no MT à medida em que se aumentava a concentração de STS. Em dgt tais diferenças não foram observadas. Quando se adicionou fluridone, à medida que se aumentou a dose, houve uma maior inibição do crescimento radicular, sendo que esta inibição foi menos acentuada em Nr e dgt. Em potencial de 0,6 MPa a inibição foi mais acentuada mas seguiu a mesma tendência observada em água. Em altas concentrações de fluridone houve ramificação das raízes, interferindo no comprimento radicular. Pode-se concluir que em condições de déficit hídrico moderado há um aumento do crescimento radicular quando comparado a condições normais de suprimento hídrico. Esse crescimento provavelmente é controlado por um balanço ABA/IAA, o qual modula a resposta ao etileno.Drought is the major abiotic plant stress factor. Among the mechanisms of water deficit resistance the root growth response has expressive importance. This response seems to be regulated by hormones. An interesting method to study hormone regulated processes is the use of hormonal mutants. The tomato cultivar Micro-Tom (MT) have reduced size and short life cycle and therefore constitutes an excellent genetic model for physiology studies. Hormonal mutants in MT with low endogenous ABA (sit and flc), ethylene insensitivity (Nr), ethylene overproduction (epi) and auxin insensitivity (dgt) constitute valuable tools to study hormone action in plant development.The present work aimed to study the hormonal interaction in the control of root growth of tomato MT subjected to water deficit. Germinated seeds of MT and mutants epi, sit, Nr, e dgt were placed in a black Ger-Box containing water and PEG 6000 solutions with potentials of - 0,3; -0,6; -0,9 e 1,2 MPa. After 5 days the length of root and hypocotyls were measured. Others experiments were conducted in Ger-Box containing ethylene action inhibitor, silver thiosulphate (STS), ABA biosynthesis inhibitor (Fluridone) and an ethylene releaser, 2-chloroethyl-phosphonic acid (CEPA) in different concentrations in water and in a -0,6 MPa osmotic potential PEG solution. After 5 days the length of the roots were measured. The PEG solution of 0,6 MPa promoted root growth in MT, dgt, epi and in with less intensity in Nr . The promotion of root growth did not occur in sit. In the mutant sit, low potential caused a swelling in the roots similar to excess ethylene symptoms. When CEPA was used, a severe inhibition of root growth occurred. The inhibition was less intense in dgt. In the 0,6 MPa solution the inhibition was more severe than occurred in water in MT. When ethylene action was inhibited by the application of STS, a greater difference of root growth between water and 0,6 MPa PEG solution occurred as the STS concentration increased. In the mutant dgt these differences were not observed. In the experiment with fluridone as the dose increased the inhibition in the root growth increased concomitantly. The inhibition was less severe in Nr and dgt. In higher doses of fluridone root ramification occurred, interfering in the primary root length. By these results it can be concluded that a moderate water deficit promotes root growth better than in a normal water supply condition. Probably this growth is regulated by an ABA/IAA balance which modulates ethylene response.
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Ogallo, Leopold Juma. "Induction of resistance to the root-knot nematode, Meloidogyne hapla, with other Meloidogyne species, on tomato and pyrethrum plants." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/187065.
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Resistance to the root-knot nematode, Meloidogyne hapla, was systemically induced on tomato and pyrethrum plants by advance inoculations with mildly virulent M. incognita and M. javanica, respectively. The reproduction of M. hapla was reduced by 84% on tomato (var. Celebrity), and by 72% on pyrethrum (clone 223) in greenhouse experiments, and by 55% on pyrethrum plants on field-plot experiments, relative to the non-induced controls. The magnitude of induced resistance increased with increasing intervals between the applications of resistance inducer and challenge nematode inocula, from 0 to 10 day intervals, then levelled off, for both tomato and pyrethrum. Induced resistance increased also with increasing levels of inducer inoculum, from 0 to 5,000 infective juveniles per plant in 500 ml pots, for both tomato and pyrethrum. Advance inoculation of one halves of partially-split root systems with resistance-inducing nematodes resulted in protection of the other halves from challenge nematodes. The observation indicated the systemic translocation of induced resistance factors from sites of induction to remote plant parts. Advance inoculations of host plants with the virulent M. hapla increased susceptibility in the plants to secondary nematode inocula, such that the originally non-virulent M. incognita and M. javanica subsequently attained enhanced reproduction rates comparable to M. hapla. Pyrethrum seedlings which received advance inoculation with M. javanica prior to challenge with M. hapla had growth rates comparable to those of nematode-free controls, while the unprotected M. hapla-infected plants were stunted up to 33%, in greenhouse experiments. In field plot experiments, the unprotected pyrethrum seedlings were stunted up to 36%, relative to plants with induced resistance. These results suggest that initial incompatible or compatible plant-nematode interactions conditioned the plants to increased resistance or susceptibility, respectively, against subsequent invading nematodes. As such, advance inoculations of plants with incompatible or mildly virulent nematodes, could be a prospective method of protecting plants against virulent nematodes.
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Tseke, Pontsho Edmund. "Responses of tomato plant growth and root-knot nematodes to phytonematicides from fermented fresh fruits of two indigenous cucumis species." Thesis, University of Limpopo, 2013. http://hdl.handle.net/10386/1673.
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Thesis (M.Sc. (Plant Production)) -- University of Limpopo, 2013Two phytonematicides were researched and developed from fermented crude extracts of wild watermelon (Cucumis africanus) and wild cucumber (Cucumis myriocarpus) fruits for use as alternatives to methyl bromide in managing root-knot (Meloidogyne species) nematodes in tomato (Solanum lycopersicum) production. Fruits of C. africanus contain cucurbitacin B (C32H48O8), while those of C. myriocarpus contain cucurbitacin A, which comprises cucumin (C27H40O9) and leptodermin (C27H38O8). Phytonematicides from C. africanus and C. myriocarpus fruits are referred to as nemafric-B and nemarioc-A, respectively. The two phytonematicides, due to their origin from plant species with allelochemicals, have high potential of being phytotoxic to crops. The use of the Curve-fitting Allelochemical Response Dosage (CARD) computer-based model assisted in the establishment of concentrations which were stimulatory to growth of tomato (Solanum lycopersicum) plants, while exhibiting nematoxic properties to Meloidogyne species. The two phytonematicides were developed from crude extracts of fruits dried at 52˚C in air-forced ovens and ground in a Wiley mill through 1-mm-opening sieves. However, equipment for drying and grinding fruits would not be accessible to smallholder farmers who wished to prepare their own products on-farm. The objective of this study therefore, was to determine whether nemafric-BL and nemarioc-AL produced from fresh fruit of the two Cucumis species would be suitable for use (i.e. non phytotoxic) in tomato production for managing population densities of M. incognita race 2. In order to distinguish the products of fresh (F) fruits from those of dried (D) fruits, they were code-named nemafricF-BL or nemariocF-BL and nemafricD-BL or nemariocD AL, respectively, where G and L denoted granular and liquid formulations, respectively. Tomato cv. ‘Floradade’ seedlings were infested with 3 000 eggs and second-stage xv juveniles of M. incognita race 2. An equivalent of 40 g and 80 g dried fruit mass of nemafric-B and nemarioc-A, namely, 284 g and 411 g fresh fruit mass for nemafric-B and nemarioc-A, respectively, were separately fermented using EMROSA effective micro-organisms mixed with 16 L chlorine-free tapwater in 20 L container for 14 days at ± 25˚C, allowing pH to gradually decline to ± 3.7. Separate experiments for each product run concurrently. Treatments, namely, 0, 2, 4, 8, 16, 32 and 64% concentrations, where for instance, 2% = 20 ml/1000 ml x 100, were arranged in a randomised complete block design, with 10 replications. Blocking in the greenhouse was done for wind direction which was regularly erected by fans for cooling down the greenhouse. At 56 days after weekly application of each treatment, flower number, fruit number, dry shoot mass, dry root mass, dry fruit mass, plant height, stem diameter and nematode numbers were each subjected to analysis of variance. Nematode data were, prior to analysis, transformed using log10(x + 1), but untransformed data were reported. Using the sum of squares, nemafric-BL and nemarioc-AL treatments affected dry root mass, dry shoot mass, flowers number, fruit number, plant height and stem diameter. Nemafric-BL contributed 67%, 78%, 58%, 43%, 60% and 26%, while nemarioc-AL contributed 71%, 61%, 19%, 35%, 34% and 24% to total treatment variation of the six respective variables. Plant variables with significant (P ≤ 0.05) treatment effects were further subjected to the CARD model to generate seven biological indices, with three distinct phases, namely, stimulation, neutral and inhibition phases. Using the quantified stimulation phase, the mean concentration stimulation range (MCSR) was computed for each variable using two biological indices, namely, threshold stimulation point (Dm) and saturation point (Rh). The CARD model explained 98%, 99%, 98% and 98% of the quadratic models of dry root mass, dry shoot mass, plant height and stem diameter, xvi respectively, against increasing concentrations of nemarioc-AL. Similarly, the CARD model explained 99%, 96%, 84% and 93% of total treatment variation in the respective plant variables. The integrated MCSR [MSCR = Dm + (Rh/2)] for nemafric-BL on tomato plants was 7%, while that for nemarioc-AL was 4%. In the CARD model, the overall sensitivities (∑k) of tomato plants exposed to nemafric-BL and nemarioc-AL were 3 units and 5 units, respectively. Tomato plants were therefore, less sensitive to nemarioc-AL since it had higher ∑k value than nemafric-BL. At 4% nemarioc-AL and at 7% nemafric-BL, the two phytonematicides were each highly suppressive to population densities of M. incognita race 2. In conclusion, on the basis of non-phytotoxicity of the computed MCSR values and their suppressive effects on population densities of M. incognita race 2, the smallholder farmers could produce nemafric-BL and nemarioc-AL phytonematicides on-farm. However, the production of the two products from fresh fruits would not be sustainable since fruits of the two Cucumis species are highly seasonal due to the high incidence of post-harvest decays.
The Land Bank Chair of Agriculture – University of Limpopo, Limpopo Agro-processing Technology Station,and the Flemish Interuniversity Council of Belgium
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Tabatabaei, Seyed Jalal. "Yield, quality and nutritional status of tomato (Lycopersicon esculentum) fruits as affected by aerial environment and nutrition distribution in the root zone." Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250733.
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Khosa, Mbokota Candy. "An investigation into the potential of crude and partially separated material of selected non-crop plant species as control agents of root-knot nematodes (Meloidogyne incognita) in tomato / Mbokota Candy Khosa." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8705.
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Plant-parasitic nematodes (PPN) are a serious problem in vegetable production and can
cause severe damage to several crops. In rural, low-input farming nematode damage is
much higher and yields can be completely destroyed. Some Commercial nematicides have
been withdrawn from the market due to health and environment concerns. These need to
be replaced by alternative nematode control strategies of which soil amendments is one
alternative. Nine non-crop plant species used in various forms in traditional healing, viz.
Cassia abbreviata, Cissus cactiformis, Euphorbia ingens, Ipomoea kituiensis, Maerua
angolensis, Senna petersiana, Synadenium cupulare, Tabernaemontana elegans and Urginea
sanguinea were screened under glasshouse conditions for their effect on the plant-parasitic
nematode (PPN) (Meloidogyne incognita) on tomato. Subsequent assessments in microplots
and in the field supported the glasshouse results in terms of suppression of root-knot
nematode numbers with crudely milled soil amendments of C. cactiformis, M. angolensis
and T. elegans. Tomato growth responses in these trials showed a tendency of phytotoxic
effects after treatment of soil with crude leaf meal of E. ingens and S. cupulare. In the
microplot study, the overall soil-amendment treatment effect was greater than that of three
soil types on the performance of the tomato, although soil type might have had an effect on
nematode suppression. Due to lack of correspondence between tomato leaf nutrient
contents and the nutrient contents of the soil amendments it is suggested that these noncrop
materials had negligible soil fertilization effects.
In vitro bioassay studies confirmed that extracts of varying polarity of both plant products
M. angolensis and T. elegans might be toxic to J2 stages of the root-knot nematode M.
incognita. All extracts tested of M. angolensis caused immobility of J2, whereas only three
extracts of T. elegans affected mobility of J2 adversely. Duration to 50 % effect, as well as
extract concentration to cause immobility of the J2 varied but where movement ceased the
J2 did not recover for up to 98 hours.
This study has demonstrated the potential of locally available botanical materials for use as
amendments in plant-parasitic nematode management and tomato growth and productivity
improvement. This would particularly be true for small-scale application in subsistence agriculture. It is believed that these amendments could be used as control measures in
integrated nematode control strategies. Their potential use could be adopted by small-scale
farming communities, domestic gardeners and commercial farmers in the Mpumalanga,
Limpopo and Kwazulu/Natal Provinces of South Africa where the relevant materials are
available in useful quantities. Over-exploitation of natural resources should be avoided at all
cost, however.Thesis (PhD (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013
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Graças, Jonathas Pereira das. "Aliviação do estresse por baixo pH na raíz do cultivar Micro-Tom de tomateiro via exposição gradual ou tratamento hipo-osmótico prévio: possível papel de modificações na parede celular." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11144/tde-29052013-161132/.
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Os solos ácidos (pH < 5,0) representam cerca de 40 % das áreas agricultáveis no mundo. Nestes solos ocorre a solubilização de formas tóxicas de alumínio que inibe o crescimento radicular. Independente da presença do Al, o baixo pH pode ser tóxico à raiz, afetando a viabilidade celular no ápice e o crescimento radicular. Há evidências de que o estresse por H+ e/ou Al³+ afetam a parede celular. Por outro lado, modificações na parede podem determinar o grau de tolerância da planta quando submetidos a estes estresses. Assim, utilizou-se de duas abordagens para investigar se possíveis modificações na parede celular melhorariam o crescimento e viabilidade celular na exposição a H+ e Al³+. Na primeira, raízes de plantas do cultivar Micro-Tom (MT) de tomateiro (Solanum lycopersicum L.), com 2 e 13 dias de desenvolvimento, foram expostas de forma direta ou gradual ao baixo pH. Na segunda abordagem, as raízes foram submetidos a um tratamento hipo-osmótico antes de serem expostas a pH 4,0 ou 4,5 + Al. Em plantas com 2 e 13 dias, a exposição gradual foi realizada alterando o pH ao longo de 12 e 24 h, respectivamente. No tratamento hipo-osmótico (priming), as plantas foram transferidas de uma solução de alta osmolaridade (150 mM) para uma com baixa osmolaridade (0,5 mM), a pH 5,8, por 0; 0,5; 1 e 2 h antes de serem expostas a pH 4,0 ou 4,5 + Al por 12h. Como controles, raízes não receberam tratamento osmótico ou foram mantidas continuamente em alta osmolaridade. O crescimento de raízes expostas diretamente a pH 4,5 foi cerca de metade do controle a pH 5,8 e a pH 4,0 foi nulo. Ao contrário do esperado, na exposição gradual a pH 4,5, as raízes cresceram menos do que aquelas expostas diretamente a este pH e a pH 4,0 o crescimento continuou insignificante. No entanto, raízes expostas gradualmente ao pH 4,0 mantiveram a viabilidade das células do ápice, ao contrário daquelas expostas diretamente. Assim, a redução do crescimento radicular pela exposição a baixo pH pode ser uma resposta gerada pela própria planta, não sendo necessariamente decorrente da ação direta do pH. O priming hipo-osmótico antes da exposição a pH 4,0 permitiu a manutenção da viabilidade celular e um crescimento radicular de até 38% das raízes controle a pH 5,8, enquanto que nos controles a pH 4,0 as células morreram e o crescimento foi praticamente nulo. Em pH 4,5 + 5 ?M de Al o priming não reverteu a inibição do crescimento radicular, indicando que as respostas para H+ e Al³+ são diferentes. Ficou evidente que a atividade de GPX está envolvida nas respostas encontradas tanto na exposição gradual a baixo pH como no tratamento hipo-osmótico anterior ao baixo pH, mas não foi possível determinar se é consequência ou uma das possíveis causas destas respostas. No seu conjunto, os dados indicam que possíveis mudanças na parede celular podem estar envolvidas na melhoria do crescimento radicular e viabilidade celular do ápice durante o estresse.Acidic soils (pH <5.0) represent about 40% of the arable land in the world. In these soils, toxic aluminum becomes soluble and inhibits root growth. Regardless of Al, low pH is, in itself, also toxic, decreasing cell viability and root growth. There is evidence that H+ and Al3+ can affect the cell wall. Reversely, modifications in the wall may determine the degree of tolerance of roots subjected to these stresses. Therefore, we used two approaches to investigate whether possible changes in the cell wall improve growth and cell viability upon exposure to H + and Al³+. In the first approach, roots of plants of the Micro-Tom (MT) cultivar of tomato (Solanum lycopersicum L.), at 2 and 13 days of development, were exposed directly or gradually to low pH. In the second approach, the roots were subjected to hypoosmotic treatment prior to being exposed to pH 4.0 or 4.5 + Al. In 2- and 13-day plants, gradual exposure was achieved by changing the pH over a 12 and 24 h period, respectively. In the hypo-osmotic pre-treatment (priming), plants were transferred from a high osmolarity solution (150 mM) to another with low osmolarity (0.5 mM), at pH 5.8, for 0, 0.5, 1 and 2 h before being exposed to pH 4.0 or 4.5 + Al for 12h. As controls, roots did not receive any osmotic treatment or were maintained continuously at high osmolarity. Growth of roots exposed directly to pH 4.5 was about half that of control roots at pH 5,8 and at pH 4.0 root growth was suppressed. Different from expected, roots exposed gradually to pH 4.5 grew less than those exposed directly to pH 4.5 and at pH 4.0, root growth remained negligible. However, cell viability was maintained in roots exposed gradually to pH 4.0, unlike those exposed directly. Thus, decreased root growth upon exposure to low pH may be a response generated by the plant itself rather than the direct effect of pH. In roots subjected to hypo-osmotic priming prior to exposure to pH 4.0, cell viability was maintained and root growth was up to 38% of that of control roots at pH 5.8, whereas in control roots at pH 4.0, cell death occurred and root growth was insignificant. At pH 4.5 + 5 uM Al, priming did not reverse the inhibition of root growth, suggesting that responses to H+ and Al3+ are different. GPX was involved in responses to both gradual exposure to low pH and to hypo-osmotic treatment prior to low pH, but it was not possible to determine whether this was a consequence or one of the possible causes of these responses. Taken together, the data indicate that possible changes in the cell wall may be involved in improving root growth and cell viability of the root apex during stress.
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Andrade, Linares Diana Rocío. "Characterization of tomato root-endophytic fungi and analysis of their effects on plant development, on fruit yield and quality and on interaction with the pathogen Verticillium dahliae." Phd thesis, Universität Potsdam, 2011. http://opus.kobv.de/ubp/volltexte/2011/5137/.
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Non-mycorrhizal fungal endophytes are able to colonize internally roots without causing visible disease symptoms establishing neutral or mutualistic associations with plants. These fungi known as non-clavicipitaceous endophytes have a broad host range of monocot and eudicot plants and are highly diverse. Some of them promote plant growth and confer increased abiotic-stress tolerance and disease resistance. According to such possible effects on host plants, it was aimed to isolate and to characterize native fungal root endophytes from tomato (Lycopersicon esculentum Mill.) and to analyze their effects on plant development, plant resistance and fruit yield and quality together with the model endophyte Piriformospora indica.
Fifty one new fungal strains were isolated from desinfected tomato roots of four different crop sites in Colombia. These isolates were roughly characterized and fourteen potential endophytes were further analyzed concerning their taxonomy, their root colonization capacity and their impact on plant growth. Sequencing of the ITS region from the ribosomal RNA gene cluster and in-depth morphological characterisation revealed that they correspond to different phylogenetic groups among the phylum Ascomycota. Nine different morphotypes were described including six dark septate endophytes (DSE) that did not correspond to the Phialocephala group. Detailed confocal microscopy analysis showed various colonization patterns of the endophytes inside the roots ranging from epidermal penetration to hyphal growth through the cortex. Tomato pot experiments under glass house conditions showed that they differentially affect plant growth depending on colonization time and inoculum concentration.
Three new isolates (two unknown fungal endophyte DSE48, DSE49 and one identified as Leptodontidium orchidicola) with neutral or positiv effects were selected and tested in several experiments for their influence on vegetative growth, fruit yield and quality and their ability to diminish the impact of the pathogen Verticillium dahliae on tomato plants. Although plant growth promotion by all three fungi was observed in young plants, vegetative growth parameters were not affected after 22 weeks of cultivation except a reproducible increase of root diameter by the endophyte DSE49. Additionally, L. orchidicola increased biomass and glucose content of tomato fruits, but only at an early date of harvest and at a certain level of root colonization. Concerning bioprotective effects, the endophytes DSE49 and L. orchidicola decreased significantly disease symptoms caused by the pathogen V. dahliae, but only at a low dosis of the pathogen.
In order to analyze, if the model root endophytic fungus Piriformospora indica could be suitable for application in production systems, its impact on tomato was evaluated. Similarly to the new fungal isolates, significant differences for vegetative growth parameters were only observable in young plants and, but protection against V. dahliae could be seen in one experiment also at high dosage of the pathogen. As the DSE L. orchidicola, P. indica increased the number and biomass of marketable tomatoes only at the beginning of fruit setting, but this did not lead to a significant higher total yield. If the effects on growth are due to a better nutrition of the plant with mineral element was analyzed in barley in comparison to the arbuscular mycorrhizal fungus Glomus mosseae. While the mycorrhizal fungus increased nitrogen and phosphate uptake of the plant, no such effect was observed for P. indica.
In summary this work shows that many different fungal endophytes can be also isolated from roots of crops and, that these isolates can have positive effects on early plant development. This does, however, not lead to an increase in total yield or in improvement of fruit quality of tomatoes under greenhouse conditions.Endophyten, die nicht zu den Mykorrhizapilzen gehören, können das Innere von Wurzeln ohne sichtbare Krankheitssymptome besiedeln und bilden so mit der Pflanze neutrale oder mutualistische Wechselwirkungen. Diese Pilze, auch als nicht-clavicipetale Endophyten bekannt, haben ein breites Wirtsspektrum von mono- und dikotyledonen Pflanzen und weisen eine hohe Diversität auf. Einige von ihnen fördern Pflanzenwachstum und erhöhen Resistenz und Toleranz gegenüber biotischem und abiotischem Stress. Ausgehenden von diesen möglichen Effekten auf ihre Wirtspflanzen war das Ziel der vorliegenden Arbeit die Isolierung und Charakterisierung neuer pilzlicher Wurzelendophyten der Tomate (Lycopersicon esculentum Mill.) und die Analyse ihres Einflusses auf Pflanzenentwicklung und Pflanzenresistenz, sowie auf Ertrag und Fruchtqualität unter Einbeziehung des Modellendophyten Piriformospora indica. Aus vier verschiedenen Anbaugebieten in Kolumbien konnten 51 neue Pilzstämme von oberflächensterilisierten Tomatenwurzeln isoliert werden. Diese Isolate wurden vorcharakterisiert und 14 potentielle Endophyten bezüglich ihrer Taxonomie, ihrer Besiedlungsmuster und ihres Einfluss auf das Pflanzenwachstum näher untersucht. Sequenzierung der ITS Region des ribosomalen RNA Genclusters und genaue morphologische Charakterisierung zeigten, dass sie zu verschiedenen phylogenetischen Gruppen innerhalb der Ascomycota gehören. Neun Morphotypen ließen sich beschreiben, wobei sechs zu den ‚Dark Septate Endophytes’ (DSEs) gehören, aber nicht mit der bekannten Phialocephala Gruppe verwandt waren. Ausführliche konfokale mikroskopische Untersuchungen ergaben sehr verschiedene Besiedelungsmuster der Wurzelendophyten vom Endringen in die Epidermis bis zum Hyphenwachstum durch den Kortex. Topfexperimente unter Gewächshausbedingungen zeigten dass die Isolate in Abhängigkeit von der Inokulumkonzentration und der Zeit der Besiedlung das Wachstum der Tomaten sehr unterschiedlich beeinflussten. Drei neue Isolate (die beiden unbekannte pilzlichen Endophyten DSE48 und DSE49 und eines identifiziert als Leptodontidium orchidicola) mit neutralen oder positiven Effekten wurden für weitere Versuche ausgewählt. In mehreren Experimenten sollte ihr Einfluss auf das vegetative Wachstum, auf Ertrag und auf Fruchtqualität untersucht werden, sowie ihre Fähigkeit die Auswirkungen des Pathogens Verticillium dahliae auf Tomatenpflanzen zu vermindern. Obwohl wachstumsfördernde Effekte durch alle drei Pilze in jungen Pflanzen beobachtet wurden, waren vegetative Wachstumsparameter nach 22 Wochen der Besiedlung nicht mehr beeinflusst bis auf ein signifikante Erhöhung des Wurzeldurchmessers durch den Endophyten DSE49. L. orchidicola dagegen erhöhte die Biomasse und den Glukosegehalt der Früchte, aber nur zu frühen Ernteterminen und bei einer bestimmten Intensität der Wurzelbesiedelung. Hinsichtlich eines schützenden Effekts, konnten die Endophyten DSE49 und L. orchidicola die Krankheitssymptome, die durch V. dahliae verursacht wurden, vermindern, aber nur bei einem geringen Pathogendruck. Um zu überprüfen, ob der Modellendophyt P. indica in Produktionssytemen eingesetzt werden kann, wurde seine Auswirkungen auf Tomaten untersucht. Ähnlich wie die neuen pilzlichen Isolate, zeigte aber auch er seinen fördernden Einfluss nur auf das frühe vegetative Wachstum. Schützende Effekte gegen V. dahliae konnten ebenfalls nur bei niedrigem Pathogendruck konstant beobachtet werden. Wie L. orchidicola erhöhte P. indica die Biomasse an marktfähigen Tomaten am Anfang des Fruchtansatzes, was nicht zu einem insgesamt höheren Ertrag führte. Ob die beobachteten Effekte auf ein verbesserte Nährstoffversorgung der Pflanze zurückzuführen seien, wurde in Gerste im Vergleich mit dem arbuskulären Mykorrhizapilz Glomus mosseae untersucht. Während der Mykorrhizapilz sowohl Phosphat wie Stickstoffaufnehme der Pflanze erhöhte, konnte dies für P. indica nicht festgestellt werden. Zusammenfassend zeigt diese Arbeit, dass auch aus Wurzeln von Kulturpflanzen viele verschiedene pilzliche Endophyten isoliert werden können, und dass einige von diesen durchaus einen positiven Effekt auf die frühe Pflanzenentwicklung aufweisen. Zumindest für Tomate unter Gewächshausbedingungen führen diese Effekte aber nicht zu einer Erhöhung des Gesamtertrags oder einer nachhaltigen Verbesserung der Fruchtqualität.
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Thoma, Rahere [Verfasser], Klaus [Gutachter] Theres, Ute [Gutachter] Höcker, and Wolfgang [Gutachter] Werr. "Functional Analysis of the GRAS Gene LATERAL SUPPRESSOR Arabidopsis Development of in Root and tomato / Rahere Thoma ; Gutachter: Klaus Theres, Ute Höcker, Wolfgang Werr." Köln : Universitäts- und Stadtbibliothek Köln, 2019. http://d-nb.info/1215293828/34.
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Al-Saqer, Fahad Abdullah. "Studies on the efficacy of Paecilomyces lilacinus, Pochonia chlamydosporia and Pasteuria penetrans for the control of Saudi Arabian root-knot nematode, Meloidogyne javanica, on tomato plants." Thesis, University of Reading, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414604.
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Martinuz, Guerrero Alfonso P. [Verfasser]. "Interrelationships between mutualistic endophytic microorganisms, the root-knot nematode Meloidogyne incognita and the sap-sucking insect Aphis gossypii on tomato, squash and Arabidopsis / Alfonso P. Martinuz Guerrero. Landwirtschaftliche Fakultät." Bonn : Universitäts- und Landesbibliothek Bonn, 2012. http://d-nb.info/1019452021/34.
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Lopes, Gabriel Lourenço. "Parâmetros genéticos da resistência à murcha-bacteriana em porta-enxertos de tomateiro." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/11/11137/tde-06022019-144405/.
Full textAbstract:
O tomateiro (Solanum lycopersicum L.) é uma das plantas cultivadas de maior importância no mundo, sendo uma das principais hortaliças em importância econômica no Brasil. A murcha-bacteriana é uma doença dentre as mais limitantes para a cultura do tomateiro e o uso de cultivares resistentes à Ralstonia spp. é uma das únicas alternativas para evitar as perdas causadas por esse patógeno. Contudo, existem raríssimos estudos sobre a base genética de genótipos resistentes aos principais isolados de Ralstonia spp. Objetivou-se nesse trabalho estudar parâmetros genéticos da resistência à murcha-bacteriana em linhagens e híbridos usados como porta-enxertos de tomateiro, por meio de abordagens complementares que envolvem desde o ajuste das metodologias para indução artificial da doença, até estimativas das capacidades de combinação e a heterose entre linhagens, visando identificar cruzamentos promissores para o estabelecimento de um programa de melhoramento genético para resistência à murcha-bacteriana em tomateiro para porta-enxertos. Comparando-se quatro métodos de indução da resistência verificou-se que o método da lesão das raízes do torrão com objeto cortante (bisturi) e pulverização de 5 mL da suspensão bacteriana no torrão, comparativamente aos outros métodos avaliados, apresenta fácil execução, requer quantidades reduzidas de suspensão bacteriana e proporciona boas quantidades de plantas de tomateiro com sintomas de murcha-bacteriana, sendo o mais adequado entre os métodos testados. Foi estimada a heterose e capacidade de combinação entre linhagens de tomateiro para um isolado do biovar 2 de Ralstonia solanacearum em estágio de plântulas, em ambiente protegido, e em um solo naturalmente infestado por Ralstonia spp. Entre as linhagens avaliadas, apenas o genótipo Hawaii 7996 apresentou níveis aceitáveis de resistência, sendo necessário encontrar novas fontes de resistência para o início de um programa de melhoramento. Verificou-se que nenhuma das progênies derivadas dos cruzamentos desse estudo apresentaram resistência superior ao parental superior Além disso, foi verificada a importância dos efeitos aditivos e, consequentemente, os cruzamentos de genitores com alta CGC para o caráter e a seleção recorrente seriam as melhores alternativas no melhoramento para resistência à murcha-bacteriana. Finalmente, foram estudados os genitores e seus híbridos, utilizados como porta-enxerto em condições de campo e em ambiente protegido visando o aumento da resistência à murcha-bacteriana causada por Ralstonia spp., e incremento dos parâmetros produtivos de um híbrido comercial utilizado como copa. Verificou-se influência dos diferentes porta-enxertos em caracteres de produção e massa dos frutos e no desenvimento de copa. Caracteres relacionados ao sistema radicular dos porta-enxertos apresentaram heterose em relação aos seus genitores, com efeitos aditivos e não aditivos importantes, mostrando o desempenho das linhagens e sua contribuição para a produção de híbridos superiores. Por fim, este estudo possibilitou o melhor entendimento sobre a base genética da resistência em genótipos de tomateiro que possuem uso potencial como porta-enxertos resistentes à murcha-bacteriana.The tomato (Solanum lycopersicum L.) is one of the most important cultivated plants in the world, being one of the main vegetables of economic importance in Brazil. The bacterial wilt is one of the most limiting diseases for the tomato crop and the use of resistant cultivars to Ralstonia spp. is one of the only alternatives to avoid losses caused by this pathogen. However, there are very few studies on the genetic basis of genotypes resistant to the main isolates of Ralstonia spp. The objective of this work was to study the genetic parameters of resistance to bacterial wilt in lines and hybrids used as tomato rootstocks, through complementary approaches that range from the adjustment of the methodologies for artificial induction of the disease, to estimates of the combining abilities and heterosis among lines, aiming to identify promising crosses for the establishment of a rootstock genetic breeding program for resistance to bacterial wilt in tomatoes. Comparing four resistance induction methods, it was verified that the method of injuring roots with cutting object (scalpel) and spraying 5 mL of the bacterial suspension in the clod compared to the other\'s methods evaluated, is easiest to perform, requires less amounts of bacterial suspension and provides good amounts of tomato plants with wilt symptoms, being the most suitable among the methods tested. The heterosis and combining ability of tomato lines for a strain of biovar 2 of Ralstonia solanacearum in greenhouse at seedling stage and in soil naturally infested by Ralstonia spp were estimated. Among the lines evaluated, only the Hawaii 7996 genotype showed acceptable levels of resistance, and it is necessary to find new sources of resistance for the beginning of a breeding program. It was verified that none of the progenies derived from the crosses of this study presented superior resistance to the superior parental. In addition, the importance of the additive effects was verified and, consequently, the crossings of parents with high CGC for the character and the recurrent selection would be the best alternatives in the improvement for resistance to bacterial wilt. Finally, we studied the parents and their hybrids, used as rootstocks under field conditions and in a protected environment aiming the increasing resistance to bacterial wilt caused by Ralstonia spp., and increasing of the yield parameters of a commercial hybrid used as a scion. The influence of the different rootstocks was verified in characters of yield and mass of the fruits and in the development of the scion. Characteristics related to the root system of rootstocks showed heterosis in relation to their parents, with important additive and non-additive effects, showing the performance of the lines and their contribution to the production of superior hybrids. Finally, this study allowed a better understanding of the genetic basis of resistance in tomato genotypes that have potential use as bacterial wilt resistant rootstocks.
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Suarez-Fernandez, Marta. "Multiomics study of Pochonia chlamydosporia tritrophic lifestyle." Doctoral thesis, Universidad de Alicante, 2021. http://hdl.handle.net/10045/117991.
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En esta tesis doctoral se estudia el modo de vida tritrófico del hongo nematófago Pochonia chlamydosporia utilizando técnicas "multiómicas". Pochonia chlamydosporia (= Metacordyceps chlamydosporia) (Goddard) Zare y Gams es un hongo nematófago usado para el control de nematodos agalladores de la raíz (Meloidogyne spp.) (Forghani and Hajihassani, 2020), entre otros. P. chlamydosporia se distribuye por todo el mundo y tiene un modo de vida tritrófico, pudiendo también adoptar estilos de vida endófito y saprófito. El mecanismo que utiliza P. clamydosporia para infectar huevos de nematodo comprende la desacetilación de la quitina de su pared celular a quitosano para facilitar su degradación por quitosanasas (Aranda-Martinez et al., 2016). El quitosano es un biopolímero derivado de la quitina que también se encuentra en el exoesqueleto de artrópodos y crustáceos. El genoma de P. chlamydosporia codifica un elevado número de quitosanasas, gracias a las cuales es resistente a quitosano y puede utilizarlo como fuente de nutrientes (Palma-Guerrero et al., 2010). Ambos pueden combinarse para el control de plagas. En este trabajo de tesis doctoral se pretende estudiar mediante metabolómica, transcriptómica y genómica el modo de vida tritrófico de P. chlamydosporia añadiendo quitosano, para determinar los mecanismos de interacción del hongo en ese entorno. En último término, se pretende sentar las bases para desarrollar un sistema para reducir plagas y enfermedades de forma sostenible.
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Jones, Matthew O. "Abscisic acid biosynthesis in tomato and tobacco roots." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479001.
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Griffiths, Allen. "Abscisic acid and the water relations of tomato roots." Thesis, Bangor University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306779.
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McAvoy, Theodore Porter. "Managing Weeds and Soilborne Pests with Fumigant and Non-Fumigant Alternatives to Methyl Bromide." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/37813.
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Methyl bromide (MBr) was widely used as a soil fumigant to manage soilborne pests in plasticulture vegetable production; however, it has been banned by the United Nations Environment Programme. Alternatives to MBr must be implemented to sustain fresh market tomato productivity. Possible MBr alternatives include new fumigant compounds, improved plastic mulch, and grafting. Methyl iodide (MeI) and dimethyl disulfide (DMDS) were tested as fumigant alternatives to MBr for the control of yellow nutsedge and soilborne pathogens of tomato. Virtually impermeable film (VIF) and totally impermeable film (TIF) were tested for fumigant retention and yellow nutsedge control in tomato. Grafting onto resistant rootstocks was tested for bacterial wilt and nematode management in tomato. In the absence of a soil fumigant, TIF suppressed yellow nutsedge better than VIF. TIF increased fumigant retention compared to VIF at similar application rates. Reduced fumigant application rates could be used in combination with TIF while maintaining fumigant concentrations, weed control, and crop yields comparable to greater use rates with VIF. Shank applied DMDS rates could be lowered to 281 L/ha under TIF from 468 L/ha under VIF; shank applied MeI application rates could be reduced to 56 L/ha under TIF compared to 93 L/ha under VIF and drip applied DMDS could be reduced from 561 L/ha under VIF film to 374 L/ha under TIF. Grafting susceptible commercial tomato cultivars onto resistant tomato hybrid rootstocks increased yields and plant survival in bacterial wilt infested fields. â Cheong Gangâ , â BHN 998â , and â BHN 1054â were the best performing rootstocks for bacterial wilt resistance and tomato fruit yield in severely infested fields. Grafting increased tomato yield and decreased root galling from root-knot nematodes in an infested field. Hybrid rootstock â RST 106â resulted in the lowest root-knot nematode galling. In conclusion, TIF with reduced rates of DMDS or MeI is a viable MBr alternative for fresh market tomato production to retain effective doses of fumigant, manage yellow nutsedge and maintain yields. Grafting is an effective MBr alternative to manage bacterial wilt and root-knot nematode and maintain tomato yields.Ph. D.
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Ouellette, Nickolis Allen. "Fertility management For Tomato Production on an Extensive Green Roof." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/theses/1139.
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AN ABSTRACT OF THE THESIS OF NICKOLIS OUELLETTE, for the Master of Science degree in PLANT, SOIL AND AGRICULTURAL SYSTEMS, presented on 2012, at Southern Illinois University. TITLE: FERTILITY MANAGEMENT FOR TOMATO PRODUCTION ON AN EXTENSIVE GREEN ROOF MAJOR PROFESSORS: Dr. S. Alan Walters, Karen Stoelzle Midden The consistent supply of fresh, healthy, local foods, in urban environments is often not feasible due to the lack of available space. Green roofs offer an alternative growing space to provide vegetable products to urban markets. However, adequate fertility to maximize plant growth is often lacking in green roof media, especially after several seasons of intensive production, since these media mixes contain only various gradations of expanded lightweight clay aggregate with about 4 to 5% organic matter. This research evaluated four fertilizer treatments applied weekly to `Bush Champion II' tomato (Solanum lycopersicum) grown in a three inch extensive green roof media mix on the Southern Illinois University campus. The fertilizer treatments evaluated were: (1) vermicompost tea (from coffee grounds; 12,600 mg/kg N), 2) Miracle-Gro fertilizer (16,100 mg/kg N), 3) Organic Miracle-Gro fertilizer (6,900 mg/kg N), and 4) no fertilizer (0 mg/kg N). Water was applied through drip irrigation daily and fertilizer treatments were applied in 1.9 L of water for each plant once a week from transplant to the end of harvest. Ripe tomato fruit were harvested eight times from June to August. Plant vigor, chlorophyll content, and marketable yields were greater (P ≤ 0.05) when Miracle-Gro and Organic Miracle-Gro were used as the fertilizer source. Subsequently, the no fertilizer and vermicompost tea application resulted in less production as lower available nutrient content (especially N) in these treatments reduced tomato plant vigor and fruit yield. Although, the analysis indicated that the verimcompost tea had a relatively high amount of N, most was in the organic form and was not readily available for plant uptake. This study indicates that acceptable tomato yields can be achieved in a three-inch extensive green roof with adequate fertilizer applications.
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Chen, Clement Chuen Seng. "Salinity-induced protein synthesis in the roots of tomato, Lycopersicon esculentum." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq37497.pdf.
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Bao, Jian Rong. "Use of GUS for detection of Fusarium oxysporum in tomato roots." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ42496.pdf.
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Timney, David. "The role of the physical properties of fungicides in controlling root rot in tomatoes caused by Phytophthora capsici Leonian." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239555.
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Brassard, Louis. "Reconnaissance visuelle pour un robot-cueilleur de tomates." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1990. http://theses.uqac.ca.
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ALMASOUM, AHMED ABDUL RAHMAN. "SOIL AERATION, HORMONAL RELATIONSHIPS AND GROWTH OF TOMATO (LYCOPERSICON ESCULENTUM MILL.) UNDER DIFFERENT ENVIRONMENTS." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183877.
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Tomato plants (Lycopersicon esculentum Mill.) were grown in a greenhouse in Arizona in order to determine the effect of aeration, flooding, and exogenously applied benzyladenine (BA) on growth and cytokinin production at different growth stages. The structural changes in roots at different soil environments were also studied. Fresh and dry weight of roots and shoots and root exudate were collected at various stages of growth. Results showed that aerated plants significantly outperformed flooded and BA treated plants due to increased root and shoot output. The level of cytokinin in root exudate was higher during the early phase of vegetative growth. At the time of bud formation and anthesis, the level of cytokinin declined. In the vegetative stage, the competition between removed sinks and the rest of the shoot was reduced and, as a result, more cytokinin was believed to come from the roots to the shoots. Besides, additional carbohydrates were available to the roots. Determination of cytokinins in aerated plants showed a significant increase. However, in flooded plants, a smaller amount of cytokinin was detected. This is believed to be due to death of root apices, a major site for cytokinin production. Under experimental conditions, the application of BA to foliage of flooded plants had an adverse effect on growth of roots and shoot of tomato plants. However, a slight increase in cytokinin level was detected. Histological studies showed an increase in air-spaces (aerenchyma) in roots of flooded plants. This acclimation improved survival in inadequately aerated plants that were waterlogged.
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Sardinha, Elissena Chinaglia Zabotto. "Respostas de pêlos radiculares de tomateiro (Solanum lycopersicum L. cv Micro-Tom) submetidos a estresse por pH baixo e hipo-osmolaridade." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/64/64133/tde-06072011-110227/.
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A acidez do solo é um dos principais fatores limitantes à produção vegetal. A toxicidade por alumínio, que ocorre apenas a pH baixo, tem sido extensamente investigada, enquanto o estresse causado pelo pH baixo tem recebido pouca atenção. Os estudos nesta área quase sempre presumem efeitos aditivos, e portanto independentes, da toxicidade por Al3+ e H+. Este provavelmente não é o caso, sendo que o pH baixo pode ser um fator de predisposição das células ao Al3+. As evidências indicam que o pH baixo causa desarranjos na parede de células em crescimento, gerando estresse que pode comprometer a sua funcionalidade e integridade. É provável que a susceptibilidade a este estresse deve ser dependente da pressão de turgor. Por sua vez, o metabolismo oxidativo e a geração de espécies reativas de oxigênio (ROS) na parede celular podem modular a sua extensibilidade por romper ou criar ligações dentro ou entre cadeias de polissacarídeo. Há grande interesse em se conhecer se, à semelhança do que ocorre em leveduras, as células vegetais possuem um sistema de percepção e resposta a estresse da parede. Os pêlos radiculares em crescimento são sensíveis a pH baixo e estresse hipo-osmótico e constituem um bom modelo experimental para estes estudos. Os objetivos deste trabalho foram: a) Otimizar um sistema experimental para o estudo de pêlos radiculares de tomateiro (Solanum lycopersicum L. cv Micro-Tom); b) Avaliar as respostas dos pêlos radiculares ao estresse por pH baixo e hipo-osmolaridade; c) Examinar o papel da modulação oxidativa da parede celular nestas respostas; e d) Avaliar a resposta de diferentes mutantes hormonais de Micro-Tom a estes fatores de estresse. Os principais parâmetros avaliados foram a taxa de alongamento (µm.min-1) e a freqüência de rompimento dos pêlos. Tanto o estresse por pH baixo quanto choques hipo-osmóticos resultaram em taxas de alongamento significativamente diminuídos e o rompimento de pêlos radiculares, mas os efeitos dos tratamentos hipo-osmóticos foram mais marcantes. Uma curva de resposta frente à osmolaridade da solução externa revelou que a taxa de alongamento aumentou com a diminuição da osmolaridade até alcançar um limiar em que houve redução drástica da taxa de alongamento e começou-se a observar o rompimento de pêlos. Também se observou uma interação entre hipo-osmolaridade e pH baixo. O emprego do inibidor difenileno iodônio não forneceu evidências do envolvimento de NADPH oxidases da membrana plasmática na resposta de pêlos radiculares a choque hipo-osmótico ou pH baixo. Já no caso do inibidor ácido salicilhidroxâmico, encontrou-se evidências do envolvimento de peroxidases da parede. Nos mutantes hormonais dgt (pouco sensível a auxina) e epi (super produtor de etileno), mas não em not (deficiente em ácido abscísico), os pêlos radiculares apresentaram uma melhor resposta de ajustamento a choque hipo-osmótico do que Micro-Tom, reduzindo o alongamento e o rompimento dos pêlos. Este trabalho fornece fortes evidências de que os pêlos radiculares possuem um mecanismo de percepção e resposta a estresse da parede visando à manutenção de sua integridade e que apresentam bom potencial como sistema modelo nesta linha de pesquisaSoil acidity is a major factor limiting plant growth worldwide. Aluminum toxicity, which occurs only at low pH, has been extensively studied, whereas low pH stress has received much less attention. Studies on Al3+ and H+ toxicity make the underlying assumption that the effects of these stress factors are additive, and, therefore independent of each other. However, this is most likely not the case and low pH may be a factor which increases susceptibility to further injury by Al3+. There is evidence that low pH causes disruption in cell wall structure of growing cells, which might jeopardize cell wall functionality and integrity. It is likely that turgor pressure plays an important role in cell wall stress caused by low pH. The apoplastic metabolism of reactive oxygen species (ROS) can modulate cell wall extensibility by making or breaking bonds within and between cell wall polysaccharides. A major question is whether, similarly to yeast, plant cells have a cell wall integrity signaling and response system. Growing root hairs are sensitive to low pH and hypo-osmotic stress and are potentially good experimental systems for such investigations. The objectives of this study were: a) Optimize an experimental system to examine tomato (Solanum lycopersicum L. cv Micro-Tom) root hairs; b) Examine the response of root hairs to low pH and hypo-osmotic stress; c) Examine the role of oxidative modulation of the cell wall in these responses; and d) Evaluate the response of different hormonal mutants of Micro-Tom to these stress factors. Root hair elongation rates (µm.min-1) and the frequency of cell bursting were the major experimental parameters which were evaluated. Both low pH and, more markedly, hypo-osmotic stress caused significant reductions in elongation rates and the bursting of root hair tips. In a response curve to varying osmolarities of the external medium, root hair elongation rates increased with decreasing osmolarities until a threshold was reached and elongation rates decreased drastically and the bursting of root hairs began to be observed. Interactions between low pH and hypo-osmolarity were observed. The use of the inhibitor diphenylene iodonium (DPI) did not provide evidence for the involvement of plasma membrane NADPH in the response of root hairs to low pH and hypo-osmotic shock. However, a role for cell wall peroxidases was provided by use of the inhibitor salicylhydroxamic acid (SHAM). Root hairs of the hormonal mutants dgt (low sensitivity to auxin) and epi (ethylene super producer), but not not (deficient in abscisic acid), displayed a more effective response to hypo-osmotic shock than Micro-Tom, by decreasing elongation rates and cell bursting to a greater degree. This study provides strong evidence to suggest that root hairs have a cell wall integrity response system and that root hairs are potentially good cell model systems for such research
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Stanke, Rüdiger. "LeAMT1 ; 2, a molecular target to investigate ammonium transport in tomato roots and N-supply by diazotrophic bacteria." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=960055843.
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Jin, Shu. "Changes in gene expression induced by water-deficit-stress in the roots of tomato, Lycopersicon esculentum." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0027/MQ51371.pdf.
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Silva, Juliana de Oliveira. "Meloidogyne incognita na cultura do tomate: levantamento e manejo com produtos biológicos." Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/4814.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
The tomato crop is attacked by a high range of pathogens, and among them are the nematodes of genera Meloidogyne. Among the various methods of controlling these pathogens, biological control has stood out on the world stage. The nematode survey is a necessary measure to plan and achieve the appropriate management. This study aimed to make a nematode survey in different producing areas of tomatoes in the vicinity of Goiânia-GO, evaluate the efficiency of different biological products in reducing Meloidogyne incognita population in the tomato crop, and to evaluate the most effective dose of a product based on Bacillus and Trichoderma. In this study nematode survey was performed in the tomato-producing areas of the surroundings of Goiânia-GO for a better understanding of the genera occurring in this crop. Also, four experiments were conducted: two to evaluate different doses of the biological product NemOutTM (Bacillus spp. and Trichoderma longibrachiatum) and two to evaluate different commercial biological products in reducing Meloidogyne incognita population and promoting tomato growth. The survey was conducted on ten tomato areas, in two consecutive years. Soil and root samples were collected and performed the extraction of nematodes and the identification of genera. The experiments were conducted in a greenhouse at the Universidade Federal de Goiás, in polyethylene pots (5L) containing sterilized substrate 1: 1 (soil + sand) in two periods, from March to May and October to December of 2014. Inoculation was made with 2,000 eggs and J2 of M. incognita. At 45 and 65 days after inoculation (DAI) the variables plant height, fresh weight shoots, fresh weight of root, galls index and egg mass index, nematode density and reproduction factor (RF), were evaluated. Producing tomato areas around Goiania-GO showed presence of genres Meloidogyne sp., Pratylenchus sp., Helicotylenchus sp., Criconemella sp. and Tylenchus sp. There was a greater abundance and dominance of Helicotylenchus sp. and Meloidogyne sp. on tomato areas studied. The use of crop rotation and fallow were effective in reducing the population of the genera found in the study area. Saturations of higher bases were positively correlated with the population density of Helicotylenchus sp., Pratylenchus sp. and Criconemella spp. and negative with the population density of Meloidogyne sp. At 45 DAI, in the first experiment, increasing doses of NemOutTM reduced the nematode population density and de reproduction factor (RF) linearly. In tested conditions the biological products NemOutTM, Nemat®, Paecilomyces JCO®, Serenade® and isolated P. chlamydosporia Pc-10 did not affect the development of tomato plants. The Serenade® product reduced index of galls and egg mass equaling the chemical in some cases.
A cultura do tomate é atacada por uma elevada gama de patógenos, e entre eles estão os nematoides do gênero Meloidogyne. Entre os vários métodos de controle desses patógenos, o controle biológico vem se destacando no cenário mundial. Fazer um levantamento dos nematoides presentes na área de produção é uma medida necessária para se planejar e realizar o manejo adequado. Este trabalho teve como objetivo fazer um levantamento de nematoides em diferentes áreas produtoras de tomate no entorno de Goiânia-GO, avaliar a eficiência de diferentes produtos biológicos na redução da população de Meloidogyne incognita na cultura do tomate, além de avaliar a dose mais eficaz de um produto a base de Bacillus e Trichoderma. Neste trabalho foi realizado um levantamento em áreas produtoras de tomate da região do entorno de Goiânia-GO, para um melhor conhecimento dos gêneros de nematoides presentes nessa cultura. Foram realizados também quatro experimentos, dois para avaliar diferentes dosagens do produto biológico NemOutTM (Bacillus spp. e Trichoderma longibrachiatum) e dois para avaliar diferentes produtos biológicos comerciais na redução da população de Meloidogyne incognita e na promoção do crescimento do tomateiro. O levantamento foi realizado em dez áreas produtoras de tomate, em dois anos consecutivos. Foram coletadas amostras de solo e raiz. Foram realizadas as extrações dos nematoides e a identificação dos gêneros. Os experimentos foram conduzidos em casa de vegetação na Universidade Federal de Goiás, em vasos de polietileno (5L), contendo substrato esterilizado na proporção de 1:1 (solo + areia), em dois períodos, de Março a Maio e de Outubro a Dezembro de 2014. Foram inoculados 2000 ovos e J2 de M. incognita. As avaliações foram realizadas aos 45 e 65 dias após a inoculação (DAI). Foram avaliadas as variáveis altura da planta, massa fresca da parte aérea, massa fresca da raiz, índice de galhas e massas de ovos, densidade populacional do nematoide e fator de reprodução (FR). Áreas produtoras de tomate no entorno de Goiânia-GO apresentaram presença dos gêneros Meloidogyne sp., Pratylenchus sp., Helicotylenchus sp., Criconemella sp. e Tylenchus sp. Houve maior abundância e dominância de Helicotylenchus sp. e Meloidogyne sp. nas áreas de tomate estudadas. A utilização de rotação de culturas e do pousio se mostraram eficientes na redução da população dos gêneros encontrados nas áreas estudadas. Saturações de bases mais altas apresentaram correlação positiva com a densidade populacional de Helicotylenchus sp., Pratylenchus sp. e Criconemella sp. e negativa com a densidade populacional de Meloidogyne sp. Na avaliação aos 45 DAI, do primeiro experimento, doses crescentes do produto NemOutTM reduziram a densidade populacional e o fator de reprodução de M. incognita linearmente. Nas condições testadas os produtos biológicos NemOutTM, Nemat®, Paecilomyces JCO®, Serenade® e o isolado P. chlamydosporia Pc-10 não afetaram o desenvolvimento das plantas de tomate. O produto Serenade® reduziu o índice de galhas e o índice de massas de ovos se igualando ao produto químico em alguns casos.
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Kagenishi, Tomoko [Verfasser]. "Extracellular ATP Signaling is Linked to Endocytic Vesicle Recycling in Root Apex / Tomoko Kagenishi." Bonn : Universitäts- und Landesbibliothek Bonn, 2016. http://d-nb.info/1133543170/34.
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Fiedler, Kathryn. "Integrated Approach to Understanding Tomato Sour Rot and Improving Disease Management on the Eastern Shore of Virginia." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/49117.
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Sour rot of tomatoes, caused by Geotrichum candidum, occurs in the field and postharvest settings regularly, although postharvest losses are severe only in some years on the Eastern Shore of Virginia (ESV) and other tomato production regions. Fungicide products and cultural control methods are tested for efficacy utilizing a traditional wounding technique that does not properly reflect natural sour rot infections. A new inoculation technique was optimized for G. candidum using negative pressure to infiltrate the tomato stem scar with pathogenic spores. This new method creates consistently high rates of infection and more successfully creates infections in mature green and breaker fruit. The population of G. candidum on the Eastern Shore of VA (ESV) was characterized using multilocus sequencing technique. The resulting phylogenetic tree defines four distinct groups, including two with uncommon loci that distinguish them from the majority of the population. Thirty-seven G. candidum isolates were inoculated to media amended with ten fungicides and antimicrobial compounds commonly used in tomato production and postharvest treatments. Propiconazole and tebuconazole completely inhibited growth of all colonies. Cultivar trials were conducted to determine if resistance or tolerance to G. candidum occurs. Ten commonly grown round and Roma cultivars on the ESV were similarly susceptible to G. candidum, even at low inoculum levels. Field and postharvest surveys of sour rot on tomato fruit attempted to correlate disease incidence with weather conditions in order to better understand the cause of sporadic infection. Few patterns were seen consistently throughout harvest periods and years. Rainfall was positively correlated with disease 2-3 days before surveys and temperature was negatively correlated with disease 5-7 days before surveys. No in-field weather conditions were correlated with postharvest disease incidence. Greenhouse trials were conducted to assess the influence of water congested tomato fruit on susceptibility to sour rot. Tomato plants were exposed to water inundation to mimic rainfall and varying levels of irrigation, both in order to congest tomato fruit. Though water congestion was achieved, tomato fruit were equally susceptible to sour rot infections.Ph. D.