Scientific Publication

Field evaluation of transgenic pigeonpea plants for resistance to Helicoverpa armigera

Abstract

Transgenic pigeon pea lines ICPL 88039 and ICPL 87 carrying the Bacillus thuringiensis cry1Ab and soyabean trypsin inhibitor (SBTI) genes were evaluated for resistance to H. armigera under field conditions in Pattancheru, Andhra Pradesh, India, during the rainy season of 2003-05, as well as under in vitro conditions using leaves, inflorescences and pods. The lack of a significant reduction in leaf feeding, larval survival, and larval weight indicated that the levels of Cry1Ab endotoxin or SBTI present in the transgenic pigeon pea plants were not sufficient. Some plants, however, showed lower levels of leaf damage, larval survival and larval weight. Due to the inadequate levels of expression of the transgenes, resistance levels were not consistent. Neonate larvae supplemented with leaf or pod under laboratory conditions can be used effectively to evaluate transgenic pigeon pea for resistance to H. armigera