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Showing 91 to 100 of 108 (0.036 seconds)Spelling suggestions: "subject:"verticillium."" "subject:"vertcillium.""
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Verticillium longisporum on oilseed rape (Brassica napus L.) / Differential roles of salicylic acid, seed transmission and plant colonization in greenhouse and field conditionsZheng, Xiaorong 05 February 2018 (has links)
No description available.
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| 92 |
Effects of Sudangrass Cover Crop and Soil Solarization on Weed and Pathogen Management in Organic Strawberry ProductionJacobs, Timothy 01 August 2019 (has links)
Field and lab experiments were conducted to determine the efficacy of sudangrass (Sorghum X drumondii (Nees ex Steud.) Millsp. & Chase) cover crop management techniques and soil solarization on important agricultural weeds and pathogens in organic strawberry production in Central California. Lab experiments assessed the time needed to kill weed seeds at temperatures typically achieved during soil solarization (40°C, 45°C, 50°C, 55°C, and 60°C) in California. Seeds tested included little mallow, redstem filaree, bristly oxtongue, annual sowthistle, common purslane, nettleleaf goosefoot, and redroot pigweed. Efficacy of simulated solarization temperatures differed between different species. Cool-season annuals annual sowthistle and bristly oxtongue were more susceptible to heat treatments than warm-season annuals common purslane, redroot pigweed and nettleleaf goosefoot. Hard seeded weed species little mallow and redstem filaree were the least susceptible to heat treatments. Annual sowthistle, bristly oxtongue and nettleleaf goosefoot were affected at all temperatures. Redroot pigweed and little mallow were not affected by temperatures below 40°C. Common purslane was not affected by temperature below 45°C and redstem filaree was not affect by any temperatures tested. Hours of exposure and percent mortality of weed seeds were used to create thermal death models for weed seeds. Field experiments were conducted at the Cal Poly Organic Farm in San Luis Obispo, CA testing the effects of soil solarization and sudangrass residues on weeds, Verticillium dahliae populations, plant health, and yields in organic strawberry production. Using a split plot design, sudangrass was grown, mowed and then developed into two treatments: surface mulch or incorporated into the soil. The sudangrass treatments and a control were tested with and without soil solarization (n=4). Maximum soil temperatures in solarized treatments were 53°C at a soil depth of 5 cm and 42°C at a soil depth of 15 cm. Solarization reduced weed biomass between 49.8 and 95.2% during the first 3.5 months after tarp removal (p=0.03), reduced Verticillium dahliae populations by 80.7% (p=0.01), reduced plant mortality by 54.9% (pV. dahliae populations (p=0.33) or yields (p=0.25). However, mulched treatments reduced weed biomass between 45.0 and 61.3% (p=0.03) compared to other sudangrass treatments. Results indicate solarization can be used in central coast organic strawberry production to reduce hand-weeding, disease incidence, and increase yields.
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| 93 |
Fungal bioactive molecules in interactions with plants and animalsSu, Ling 15 October 2019 (has links)
No description available.
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| 94 |
Soilborne Pathogens Of Strawberry In The Central Coast Region Of California: Survey And Cover Cropping With Wheat For Management Of Macrophomina PhaseolinaSteele, Mary 01 June 2023 (has links) (PDF)
Surveys of the four major soilborne pathogens of strawberry (Fusarium oxysporum f. sp. fragariae, Macrophomina phaseolina, Phytophthora spp., and Verticillium dahliae) to determine their relative prevalence were conducted in Watsonville-Salinas, CA in 2021 and in Santa Maria, CA in 2022. All four major pathogens were detected at relatively similar prevalence in Watsonville-Salinas, between 22% and 31% of sampled fields. In Santa Maria, M. phaseolina was far more prevalent at 52% of sampled fields, the other three falling between 14% and 17%. Additionally replicated greenhouse and field trials were conducted to evaluate the effects of wheat as a single season cover crop on Macrophomina root rot of strawberry and the soil microbiome. Greenhouse trials and the first year of the field trial are described here and demonstrate a lack of substantial disease mitigation or pathogen reduction in the soil following wheat growth compared to no-treatment control. Significant changes were seen in the soil microbiome following wheat growth, including the significant amplification of several bacterial species known to be antagonistic to plant-pathogenic fungi.
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| 95 |
Adhesion of the rapeseed pathogen Verticillium longisporum to its host Brassica napus: Uncovering adhesion genes and the evolutionary origin of the fungus / Die Adhäsion der Raps Erreger Verticillium longisporum seinen Wirt Brassica napus: Aufdeckung Adhäsion Genen und der evolutionären Ursprung des PilzesTran, Van Tuan 02 May 2011 (has links)
No description available.
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| 96 |
PLANT-ENDOPHYTE INTERPLAY PROTECTS TOMATO AGAINST A VIRULENT VERTICILLIUM DAHLIAEShittu, Hakeem Olalekan 05 October 2010 (has links)
When tomato Craigella is infected with Verticillium dahliae Dvd-E6 (Dvd-E6), a tolerant state is induced with substantial pathogen load, but few symptoms. Unexpectedly, these plants are more robust and taller with Dvd-E6 behaving as an endophyte. Some endophytes can protect plants from virulent pathogens. This research was undertaken to improve understanding of the cellular and molecular nature of Verticillium tolerance in tomato, especially whether infection by Dvd-E6 can protect Craigella from virulent V. dahliae, race 1 (Vd1). To permit mixed infection experiments a restriction fragment length polymorphism (RFLP)-based assay was developed and used for differentiating Dvd-E6 from Vd1, when present in mixed infections. The results suggested that protection involves molecular interplay between Dvd-E6 and Vd1 in susceptible Craigella (CS) tomatoes, resulting in restricted Vd1 colonization. Further studies showed a dramatic reduction of Vd1 spores and mycelia. To examine genetic changes that account for these biological changes, a customized DNA chip (TVR) was used to analyze defense gene mRNA levels. The defense gene response was categorized into four groups. Group 1 was characterized by strong induction of defense genes followed by suppression. However, Vd1-induced gene suppression was blocked by Dvd-E6 in mixed infections.
These genes included some transcription factors and PR proteins such as class IV chitinases and beta glucanases which are known to target fungal spores and mycelia. Experiments also were repeated with a Craigella resistant (CR) isoline containing a fully active Ve locus (Ve1+ and Ve2+). The biological results showed that the presence of the Ve1+ allele resulted in restricted Vd1 colonization and, in a mixed infection with Dvd-E6, Vd1 was completely eliminated from the plant stem. Surprisingly, there was no significant increase in defense gene mRNAs. Rather, elevated basal levels of defense gene products appeared sufficient to combat pathogen attack. To investigate functional effects of the genetic changes observed, an inducible RNAi knockdown vector for a defense gene (TUS15G8) with unknown function (pMW4-TUS15G8) as well as the Ve2 resistance gene (pMW-Ve2) was prepared as a initial step for future transformation analyses. Taken together the results reveal intriguing but complex biological and molecular changes in mixed infections, which remain a basis for future experiments and potential agricultural benefits. / Canadian Commonwealth Scholarship and Fellowship Plan
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| 97 |
Identification of Arabidopsis genes involved in differential interaction phenotype establishment by distinct Verticillium spp. and isolatesStepanets, Dimitri 09 April 2018 (has links)
No description available.
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| 98 |
DEFENCE GENE EXPRESSION IN THE TOMATO-VERTICILLIUM PATHOSYSTEMCastroverde, Christian Danve 22 April 2010 (has links)
In tomato (Solanum lycopersicum), race-specific resistance against the fungal wilt pathogen Verticillium dahliae race 1 (Vd1) is established in the stem. However, the molecular factors and mechanisms leading to this resistance response are still unknown. In this study, Craigella resistant (CR) and susceptible (CS) tomato plants were successfully infected with Vd1 and this was verified by fungal quantification and symptom score assays. Previous microarray results showed interesting patterns of defence gene expression that correlated with biological phenomena. Plant defence genes code for proteins that are responsible for or associated with the plant resistance response. Through RT-PCR, this thesis set out to confirm these microarray observations and also to generate expression data for genes in which sensitivity was an issue in the microarray. The standard RT-PCR data confirmed a number of the microarray results, but some conflicts remained. From the defence genes investigated, there was agreement between the microarray data and the RT-PCR data for pre-mRNA processing factor 8, class IV chitinase, cyclin-dependent kinase inhibitor and IMP dehydrogenase/GMP reductase. Partial agreement was observed for genes coding for ethylene response factor 2, phenylalanine ammonia lyase and P6 protein. However, there
was total disagreement for 14-3-3, beta-glucanase, P1a, RNA-binding protein, calcium-binding protein and S-Adenosyl-L-methionine: hydroxide adenosyltransferase. Real-time
RT-PCR was attempted to clarify the remaining issues but further discrepancies arose, particularly in the Ve resistance genes. To resolve these discrepancies, two approaches were designed: (1) one based on the use of a universal internal control and (2) another based on restriction enzyme digestion. In general, the results were more consistent with standard RT-PCR. Overall, this study showed that standardization of a system involving vascular pathogens, leading to reproducible analysis, was possible but only with proper controls and additional validation. Standard RT-PCR appeared to offer a more accurate picture of the expression of defence genes in the tomato-Verticillium pathosystem. The defence gene expression results confirmed in this study remain as potential insights into the molecular mechanisms for Verticillium resistance in tomato plants.
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| 99 |
Strawberry Growth, Yield, Fruit Nutrition, and Control of Verticillium Wilt with Pre-plant Soil Fumigants, Ozone, and Biological ControlScurich, Justin J 01 April 2012 (has links) (PDF)
Verticillium wilt is a widespread soilborne disease of strawberry historically controlled by soil fumigation with methyl bromide (MB). MB was banned by the United Nations in 1995 and will be completely phased out by 2015. Research has concentrated on alternative methods of disease control without finding a single alternative able to replace MB in widespread disease control and yield increase. For the current study, strawberries were greenhouse grown in container pots filled with soil from both infested and non-infested areas of a commercial strawberry field in Watsonville, CA. Treatments included pre-plant soil fumigation with commercially available formulations of methyl bromide, chloropicrin, and 1, 3-Dichloropropene. Additional treatments included ozone gas (six treatments) and biological control (three treatments). Collected data included total plant yield, individual berry weight, number of fruit produced per plant, plant vegetative weight, infection status, and mineral concentration of fruit (calcium, magnesium, potassium, iron, zinc, manganese, carbon, and nitrogen). Plants grown in ‘clean’ soil were less likely than plants grown in ‘infested’ soil to be infected with Verticillium. Plants grown in soil treated with MB had higher plant weight and yield than did non-treated control. Ozone and biological control treatments did not have statistically higher yield than non-treated control plants nor statistically lower yield than plants grown in soil treated with MB. Individual berry weights had a narrow range while the number of berries produced per treatment had a wide range. Data suggests strawberry yield is dependent on the number of berries produced per plant. Plants with high vegetative weight produced the highest yield suggesting large plants produce many berries resulting in higher yield.
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| 100 |
Signals and metabolic consequences during the interaction of Brassicaceae and <i>Verticillium longisporum</i> / Signale und metabolische Konsequenzen während der Interaktion von Brassicaceen und <i>Verticillium longisporum</i>Possienke, Mareike 29 February 2012 (has links)
No description available.
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