An effective pest management approach in potato to combat insect pests and herbicide

Insect pests and weeds incur significant yield losses to potato crop worldwide. The increasing crop losses provide impetus for the development of pest management strategy that is equally effective against insect pests and weeds. In the present study, a molecular approach was used to develop transgenic potato lines (cv. Marabel) effective against Colorado potato beetle (Leptinotarsa decemlineata Say), potato tuber moth (Phthorimaea operculella Z.) and Basta^® application. Agrobacterium tumefaciens strain EHA105 harboring binary vector pTF101.1 containing cry1Ac gene under the control of 35S and AoPR1 promoters was used to infect leaf discs and internodal explants. Phosphinothrincin was used at optimal concentration (2 mg/l) for the screening of primary transformants. The standard molecular assays exhibited gene integration and expression in putative transgenics. Real-time data revealed up to ninefold high cry1Ac transcript levels, whereas cry protein amount was estimated to 0.4 ppm in primary transformants. The analysis of first tuber progeny showed proper integration cry1Ac and bar genes in subsequent progeny. The transgenic plants also showed tolerance to the application of Basta^®. The efficacy of cry1Ac was evaluated by allowing larvae of Colorado potato beetle (CPB) and potato tuber moth (PTM) to feed on transgenic plants. Results revealed appreciable mortality levels of different larval instars of CPB (20-100%) and PTM (50-100%). Overall, our results exhibit the potential of these transgenic lines to be used in a potato breeding program with the purpose to control insect pests and weeds.