Scientists Compare Efficacy of Single and Stacked Bt Genes on Pink Bollworm and Tobacco Caterpillar

The introduction of Bt cotton containing a single gene (Cry1Ac) that confers resistance to bollworms has led to significant increase in the yields of growers. However, there are other major pests that are less resistant to Cry1Ac. Later on, stacked genes were introduced to Bt cotton. The information regarding the difference in efficacy of the first and second generation of Bt interspecific cotton hybrids against pink bollworm (Pectinophora gossypiella) and tobacco caterpillar (Spodoptera litura) is lacking. Thus, Hareesha Badiger and colleagues at the University of Agricultural Sciences, India conducted a field evaluation to elucidate the difference in efficacy of ten interspecific cotton hybrids with single and stacked Bt genes against pink bollworm and tobacco caterpillar under rainfed condition.

Results of the study showed that stacked Bt hybrids, particularly Steplon BG-II and Kashinath hybrids, exhibited better resistance to pink bollworm and tobacco caterpillar than the single gene Bt hybrids. All the stacked Bt hybrids had significantly lower pink bollworm and tobacco caterpillar larval population, green boll and locule damage, tobacco caterpillar infested leaves per plant, and damaged area per infested leaf compared to single gene Bt hybrids. Therefore, stacked Bt hybrids are more effective against pink bollworm and tobacco caterpillar than single gene Bt hybrids.

Read the complete research article at http://203.129.218.157/ojs/index.php/kjas/article/view/2124.