Thesis
Limited host range of Sclerotinia trifoliorum examined in comparsion to S. sclerotiorum
Washington State University
Master of Science (MS), Washington State University
12/2015
Handle:
https://hdl.handle.net/2376/102620
Abstract
Sclerotinia trifoliorum is limited in host range in comparison to other Sclerotinia species - it infects mainly cool season legumes, while S. sclerotiorum infects over 400 plant species, including all the hosts of S. trifoliorum. The mechanisms for this host limitation are currently unknown. In this study, ten diverse isolates of S. trifoliorum and ten diverse isolates of S. sclerotiorum were compared for potential factors limiting the host range of S. trifoliorum. S. trifoliorum and S. sclerotiorum were compared in culture. First, growth and its effect on medium pH of S. trifoliorum and S. sclerotiorum were examined at different temperatures and on media buffered at different pH levels. S. trifoliorum grew slower than S. sclerotiorum and did not modify its environmental pH as quickly as S. sclerotiorum at all temperatures and pH levels. Second, oxalic acid production in liquid culture was quantified. S. sclerotiorum produced significantly more oxalic acid than S. trifoliorum at both 3 and 7 days post inoculation (P≤0.0001). Third, the mating types of the S. trifoliorum isolates were determined and there was no difference in growth rates between the different mating types. S. trifoliorum and S. sclerotiorum were also compared for their ability to colonize detached leaves of cool season legumes (faba bean, pea), and warm season legumes (green bean, soybean), and detached stems of alfalfa at room temperature (20-23˚C) and 10˚C. S. trifoliorum could produce lesions on all detached leaves at all temperatures, however lesions produced were much smaller than those of S. sclerotiorum. Lesion size and lesion pH of intact plants infected with S. trifoliorum and S. sclerotiorum were also compared. Lesions produced by S. sclerotiorum were significantly larger than those produced by S. trifoliorum. Despite the significant difference in lesion size, the final pH levels of the lesions were either the same for the two isolates or statistically lower for S. trifoliorum lesions. The limited ability of S. trifoliorum to modify its environmental pH, in addition to other factors not yet determined, may limit its host range
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Details
- Title
- Limited host range of Sclerotinia trifoliorum examined in comparsion to S. sclerotiorum
- Creators
- Teresa Maria Jardini
- Contributors
- Weidong Chen (Chair)Dennis A Johnson (Co-Chair) - Washington State University, Plant Pathology, Department ofFrank Matthews Dugan (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Plant Pathology, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Number of pages
- 86
- Identifiers
- 99900525173101842
- Language
- English
- Resource Type
- Thesis