Research Accomplishment Reports 2007

Spider Mite Resistance Mechanisms in Lycopersicon hirsutum Accession LA2329

J. Snyder
Department of Horticulture

 

Project Description

Backcross hybrids with L. esculentum have been obtained and screened for spider mite resistance. A range of L. esculentum parents and selected interspecific F1 and F2 hybrids were used to obtain the backcross hybrids. Frequency of resistance to spider mites, as judged by a whole leaf bioassay, was high in these populations, indicating a dominate mode of resistance inheritance. Trichome secretions of the backcross hybrids contain sequiterpenes present in the wild, spidermite resistant parent. However, concentrations in the hybrids are lower than in the wild parent. Toxicity of the secretions from the backcross hybrids is generally less than that of the resistant parent. Also, secretions from the backcross hybrids are generally less repellent to spidermites, as judged by a bridge bioassay. Leaf disk bioassays confirm that some backcross hybrids are resistant.

Results suggest that the dominant resistance may be related to composition or abundance of trichome secretions, but also do not rule out the possibility of another mechanism of resistance, unrelated to trichome secretions. A second backcross generation has been obtained and will soon be characterized.

Impact

Results of this research when completed may lead to tomato crops that are better able to withstand insect attack. By providing a better understanding of the components of resistance, causes of resistance and mechanisms of resistance, breeding efficiency may be improved. This would result in more tomato varieties that are resistance to mites or insects.

Publications

Antonious G.F. and Snyder J.C. (2007). Impact of soil incorporated sewage sludge on herbicide and trace metal mobility in the environment. book chapter, In: Environmental Engineering & Economics, published by Dr. Michael Theophanides, Greece Institute for Education & Research, chapter 12, pp. 149-164, ISBN: 978-960-6672-13-2.

Antonious G.F. and Snyder J.C. (2007): Accumulation of heavy metals in plants and potential phytoremediation of lead by potato, Solanum tuberosum L. J. Environmental Science & Health, Part-A Toxic/Hazardous Substances & Environmental Engineering, volume 42 (6): 811-816.

Antonious G.F. and Snyder J.C. (2007) submitted a new book chapter titled "Tomato Leaf Crude Extracts for Insects and Spider Mite Control" to Tomatoes and Tomato Products: Nutritional, Medicinal and Therapeutic Properties, which will be published by Science Publishers in 2008. The book chapter is in press.

Antonious G.F., Frank Sikora , and John C. Snyder (2007). Variation in Heavy Metals Accumulation Among Hot Pepper Species. UK Agricultural Experimental Station, Fruit & Vegetable Crops Research Report # PR-555, University of Kentucky, Lexington, KY, pp. 80-82.

Antonious, G.F. and Snyder, J.C. (2007). Heavy metal concentrations in vegetables grown in soil incorporated with sewage sludge. Transactions of the Kentucky Academy of Science, 68 (1), Published Abstract, pp. 103-104.