The XIth International Symposium on Thysanoptera & Tospoviruses ( ISTT ) ( September 21-25, 2019, Kunming, China )
Examples of Abstract
Utilizing Acylsugar Chemistry for Optimal Thrips and Tospovirus Control in Tomato
John Smeda (1), Brian Leckie (1), Martha A. Mutschler (1) Diane Ullman (2), George Kennedy (3)
(1) Department of Plant Breeding and Genetics, Cornell University, 301 Bradfield Hall Ithaca, NY 14853; (2) Department of Entomology, University of California, Davis, One Shields Ave. Davis, Ca 95616, USA; (3) Department of Entomology, North Carolina State University, 2301 Gardner Hall, Raleigh, NC 27695, USA
Tomatoes are attacked by many pests, causing losses directly through feeding damage and indirectly through virus transmission. The control of insects relies heavily on pesticides, a practice that is increasingly crippled by development of pesticide-resistant insects and increased health and environmental concerns; therefore, alternative means of insect control are necessary. Acylsugars produced by some wild Solanum species, including Solanum pennellii Correll, are associated with strong insect resistance. Work with purified S. pennellii acylsugars demonstrated that acylsugars reduce feeding and oviposition by many insect species. S. pennellii accessions collected from different regions of the species native range have unique acylsugar chemotypes. This diversity among S. pennellii accessions raises questions regarding their functional differences and whether this diversity can be leveraged to optimize acylsugars as a defense strategy. Using S. pennellii LA716, Mutschler’s breeding program created an acylsugarproducing tomato, CU071026, which produces acylsucroses with defined fatty acid constituents. Using a BC1F1 population derived from CU071026 and S. pennellii LA716, a series of QTL were identified that modify acylsugar chemotype. I will present data that when these QTL were introgressed into CU071026 the resulting sister lines differed for acylsugar chemotype as predicted, confirming the function of the QTL. These lines are being used to evaluate the efficacy of the chemotype shift in planta on control of critical tomato pests. I will present recent work where lines with altered acylsugar chemotype were evaluated in field trials with natural thrips and virus pressure. Data was taken on thrips feeding and virus incidence, as well as on acylsugar level and acylsugar chemistry through gas chromatography characterization. These data will help elucidate not only the effect of the environment on acylsugar level and chemistry, but also the effect of acylsugar chemotype on insect feeding and oviposition, and also inform the breeding effort on optimal acylsugar producing lines for thrips control.