Thesis
COMPARISON OF SOLANUM SISYMBRIIFOLIUM RESISTANCE RESPONSES TO ROOT-KNOT NEMATODES AND EVALUATION OF TAXONOMIC REFERENCE DATABASES FOR NEMATODE IDENTIFICATION
Washington State University
Master of Science (MS), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000003122
Handle:
https://hdl.handle.net/2376/122561
Abstract
Plant-parasitic nematodes are economically important because of the devastating impacts they have on agricultural production. Potato growers in the Pacific Northwest (PNW) are particularly concerned with the root-knot nematodes (RKNs), Meloidogyne hapla and M. chitwoodi. The use of resistant cultivars and nematicides are common methods of control. However, resistance to RKNs has not been identified in any commercial potato cultivar, which requires scientists to explore other sources of resistance. The wild Solanum spp., Solanum sisymbriifolium, has been reported to be resistant to Globodera spp. and RKNs, both known pests of potato. The resistance response of S. sisymbriifolium to M. hapla and M. chitwoodi was characterized through evaluation of infection using different levels of nematode inoculum and at different timepoints. Solanum sisymbriifolium resistance to M. chitwoodi compared to M. hapla was heightened during this research indicating S. sisymbriifolium could be successfully used for RKN management. The other primary method of control, nematicides, is effective at controlling RKN populations but can have negative impacts on the soil ecosystems, leading to a decrease in overall soil health and reduction in crop yields. Soil health should be monitored to determine if there are negative impacts from different management practices. Nematodes are a strong bioindicator for evaluating soil health because of their physical characteristics and presence at all levels of the soil food web. Nematode identification is primarily conducted using morphological analysis; however, this is a time-consuming process that requires a high level of knowledge and expertise. An alternative method for nematode identification is metabarcoding, a DNA-based method that can be used for evaluation of the soil nematode community. However, a limitation to effective use of metabarcoding is the lack of a quality nematode-specific reference database. Development of an improved reference database, NEMATaxa, was completed through this research, and its classification capabilities were compared to the current reference database, SILVA. Comparison of the databases revealed an improved level of identification capable by the NEMATaxa reference database. Development of an improved reference database contributes to the advancement of metabarcoding being effectively used for nematode community characterization.
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Details
- Title
- COMPARISON OF SOLANUM SISYMBRIIFOLIUM RESISTANCE RESPONSES TO ROOT-KNOT NEMATODES AND EVALUATION OF TAXONOMIC REFERENCE DATABASES FOR NEMATODE IDENTIFICATION
- Creators
- Hannah V Baker
- Contributors
- Cynthia Gleason (Advisor)Inga Zasada (Committee Member)David L Wheeler (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
- Number of pages
- 137
- Identifiers
- 99900651899101842
- Language
- English
- Resource Type
- Thesis