Potential of Transgenic Grain Legumes for Pest Management and Sustainable Crop Production

Host-plant resistance to insects, in general, is controlled by quantitative traits, and as a result, the progress in developing high-yielding insect-resistant cultivars has been quite slow. With the advent of recombinant DNA technology, it has become possible to clone and insert genes into crop plants to confer resistance to insect pests. Insecticidal genes from the bacterium, Bacillus thuringiensis (Bt), which are mainly effective against the lepidopteran insects, have been inserted into several grain legumes such as - chickpea, pigeonpea, cowpea, soybean, groundnut, faba bean, lentil, field pea, greengram, and blackgram. However, there is a need to discover and deploy genes that are effective against the hemipterans and dipterans that are important pests of grain legumes. Although insect- resistant transgenic plants have been developed in several grain legumes, these have not been deployed for pest management because of the concerns raised about food safety and their possible effects on the non-target organisms. To ensure a sustainable deployment of transgenic insect-resistant grain legumes, it is important that they are compatible with other control methods, including the biological control agents that are important for natural regulation of pest populations. Toxin genes from Bt and non-Bt proteins are considered to be environmentally benign and their use will reduce the hazards associated with the use of synthetic insecticides. However, it is important to follow the bio-safety regulations, and assure the general public about the biosafety of food derived from transgenic grain legumes, and their biosafety to the non-target organisms in the environment for sustainable crop production