Submitted to: Journal of Economic Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/25/2006
Publication Date: 10/1/2006
Citation: Adamczyk Jr., J.J., Meredith, W.R. 2006. Selecting for efficacy of Bollgard cotton cultivars against various lepidoptera using forward breeding techniques. Journal of Economic Entomology. 99(5):1835-1841. Interpretive Summary: Clear differences in survival and development were observed when certain caterpillars were fed different cotton varieties containing an insect-controlling gene (Bt). For the first time, these cotton varieties were bred for different amounts of Bt. Insects that fed on the variety that contained the lower amount of Bt survived better and developed faster than those caterpillars fed the other variety which contained a higher amount of Bt.
Technical Abstract: Studies during the past five years have shown that overall level of protein (Cry1Ac) produced from the cry1Ac transgene (Monsanto Co., St. Louis, MO) differ among commercial Bollgard® cotton cultivars. These differences between cultivars are under genetic control and have been correlated with efficacy of certain lepidopteran pests. Previous studies have shown that the parental background (i.e. non-Cry1Ac conventional cultivar) has a significant influence on expression of the amount of Cry1Ac protein in Bollgard® cultivars. Unlike the backcross technique commonly used to acquire commercial Bollgard® cultivars, we used forward breeding to obtain cultivars of Bollgard® cotton that were selected for various levels of Cry1Ac. These expression differences were correlated with growth and survival of two lepidopteran pests of cotton. Implications for effective resistance management as well as relative ease of this procedure are discussed.