Thesis
Potential of green manure biofumigants and seed exudates in the control of Globodera pallida, the white potato cyst nematode
Washington State University
Master of Science (MS), Washington State University
2010
Handle:
https://hdl.handle.net/2376/102309
Abstract
The white potato cyst nematode (PCN), Globodera pallida, is a regulated pest in the United States and several other countries. Many effective synthetic nematicides known to control and eradicate G. pallida have been banned or are restricted worldwide due to negative impacts on the environment and health risks to humans. Globodera pallida was discovered in 2006 in eastern Idaho and it is important to find a control method which is economical, ecologically safe and can be used in conjunction with synthetic nematicides. Biofumigants from plant residues have been shown to be effective in controlling many soil borne pathogens. Hence, biofumigation potential of five plants used as green manures against PCN and the effects of seed exudates of these plants on the diameter of the dorsal pharyngeal gland nucleolus (DPGN) of the PCN second-stage juvenile (J2) was studied. The Brassicaceae species used were Raphanus sativus, Brassica napus, Sinapis alba, Eruca sativa and a Poaceae species, Lolium multiflorum, in greenhouse trials and seed exudate assays. Data from the green manure trials were analyzed and no significant differences (P > 0.05) were found between treatments and controls. However, the least number of cysts was produced in pots amended with R. sativus in comparison to other treatments and controls, with a 50% reduction in cysts. In addition, J2s were exposed to seed exudates to determine if any of the plants tested as biofumigants have the potential to mimic the induction of egg hatching, which is normally induced in the presence of chemical stimulants released from host plant roots. The diameter of DPGN in response to the seed exudates was measured using Nomarski microscopy and the data showed significant differences (P < 0.0001) between treatments and water control. Seed exudates from B. napus had the greatest effect on the DPGN size, resulting in the largest nucleolus among the treatments, whereas exudates from S. alba resulted in the smallest nucleolus. Therefore, R. sativus, B. napus and S. alba have the potential to reduce PCN and could be used in combination with a synthetic nematicide to aid in PCN eradication.
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Details
- Title
- Potential of green manure biofumigants and seed exudates in the control of Globodera pallida, the white potato cyst nematode
- Creators
- Zareen. Dossey
- Contributors
- Ekaterini Riga (Degree Supervisor)
- 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, Wash. :
- Identifiers
- 99900525083201842
- Language
- English
- Resource Type
- Thesis