Thesis
Evaluation of Cucurbitaceae and Solanaceae rootstocks for resistance to verticillium wilt
Washington State University
Master of Science (MS), Washington State University
05/2019
DOI:
https://doi.org/10.7273/000004021
Handle:
https://hdl.handle.net/2376/125145
Abstract
Grafting a susceptible cultivar onto a resistant rootstock can help manage verticillium wilt (caused by Verticillium dahliae), a fungal soil-borne disease that can affect watermelon, eggplant and pepper production. However, obtaining commercial rootstocks can be expensive, and their resistance to verticillium wilt is not well known. Three studies were designed to screen resistant rootstocks for verticillium wilt resistance at the Washington State University Northwestern Washington Research Center at Mount Vernon, Washington, in a field naturally infested with V. dahliae (10.5 cfu.g-1 soil on average). Plants also were inoculated with V. dahliae for uniformity. The first study screened 56 cucurbit germplasm accessions for resistance to verticillium wilt in 2017, and subsequently in 2018, 14 resistant accessions were tested for graft compatibility with watermelon cv. Secretariat. Disease level and yield of germplasm-grafted plants was similar to 'Secretariat' grafted onto commercial rootstock 'Tetsukabuto', while non-grafted 'Secretariat' did not survive. The resistant germplasm accessions could be used in rootstock breeding programs. In the second study, eggplant 'Night Shadow' grafted onto 5 commercial eggplant and tomato rootstocks, and one heirloom tomato, were screened for their resistance to verticillium wilt. In 2016, 'Night Shadow' had greatest disease incidence and severity. Disease incidence did not differ significantly between entries in 2017, but disease severity was least for 'Night Shadow'/'Survivor'. Although rootstocks 'Meet' and 'Cherokee Purple' produced the greatest yield in 2016 and 2017 respectively, 'Estamino' and 'Survivor' performed consistently both years. All of these rootstocks are suitable for grafting eggplant to manage V. dahliae. The third study evaluated 14 eggplant and 3 pepper rootstocks from the World Vegetable Center for their resistance to verticillium wilt. 'Millionaire' and 'Ace' were used as the eggplant and pepper scions, respectively. For eggplant, 'Millionaire'/VI042738 had the greatest plant height, but disease severity and yield did not differ significantly among grafted treatments. Grafting onto the rootstocks used in this study was not a viable option for disease management. For pepper, 'Ace'/VI064659 had the greatest plant height, and yield did not differ significantly among treatments. No disease symptoms were observed in any of the pepper plants, indicating peppers tested were resistant to the isolates of V. dahliae used in this study.
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Details
- Title
- Evaluation of Cucurbitaceae and Solanaceae rootstocks for resistance to verticillium wilt
- Creators
- Abigail Supreetha Attavar
- Contributors
- Carol Ann Miles (Advisor) - Washington State University, Department of Horticulture
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Horticulture
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Identifiers
- 99900890795901842
- Language
- English
- Resource Type
- Thesis