Development of pod borer resistant transgenic chickpea Cicer arietinum L lines

Abstract

i newlineABSTRACT newlineChickpea is a chief pulse crop in the Asian and African continents, but its productivity is newlinestagnating since the last decades due to the various constrains (biotic and abiotic stresses) newlineencountered during the crop s life cycle. Among the biotic stresses that affects chickpea yield newlinethe gram pod borer (Helicoverpa armigera H.) is a prominent pest of chickpea, having an newlineaverage annual yield loss of 20 - 30%. Various conventional pest management approaches have newlinebeen adopted for managing pod borer infestation, but these techniques seem to be inadequate. newlineAn alternative technique, employing genetic engineering has proven to be a potential approach newlinefor addressing the yield loss associated with wide range of insect pests, since resistance alleles newlinehave not been known in the chickpea germplasm. Various classes of insecticidal genes derived newlinefrom Bacillus thuringiensis (Bt) have been reported to be effective against wide range of insect newlinepest and are routinely employed for pest management in various crops. Bt-cry gene chickpea newlinelines are available, however resistance mechanism employing single gene may not be newlinesustainable. Furthermore, recent reports have indicated evolution in the insects for developing newlineresistance against Cry toxins. So, deployment of second gene with different mode of action is newlineimperative. Vip3Aa, gene a class of Vegetative Insecticidal Protein can be stacked with Cry newlinegene to produce broad-spectrum pod borer resistant chickpea lines. newlineIn the present study, it has been reported, the best media combination and the best explant newlineamong the tested set of growth media and different explants that can be successfully employed newlinefor regeneration and transformation in chickpea. Along with, the designing of synthetic codon newlinemodified Vip3Aa (cmVip3Aa) gene (2,370 bp) sub-cloned in a re-constructed plant expression newlinevector pRI201AN. The modified gene construct was employed for direct transformation of newlineembryonic axis (EAX) explants of chickpea, with transformation efficiency of 4.30%. newlineExistence and transmission of tran