Biotechnology for enhancement of insect resistance in rice

211-214Rice (Oryza sativa L.) is the most important food crop of the world serving as a major staple food for about 3 billion people. The pests cause millions of dollars worth of losses annually to food crops and various strategies have been used to minimise these losses. The most important and practical approach is to incorporate host resistance genes into improved crop varieties and grow pest resistant varieties. Recent advances in biotechnology particularly in cell and ti ssue culture and molecular biology have opened new avenues for developing pest resistant lines. Three biotechnological approaches arc contributing to the enhancement of pest resistance in rice. Transformation provides access to the non rice genes that are otherwise unavailable to rice breeders ego synthetic Cry 1A(b) gene for leaf folders and striped stem borer. Fertile transgenic rice was achieved, through protoplast, microprojectile bombardment and Agrobacterium tumefaciens mediated transformation methods. DNA marker aided selection is a speedy approach and also permits novel output such as pyramid of genes of similar effect. Pest resistant genes when tagged with molecular marker can be moved more rapidly from one varietal background to another and also provide an additional way for durable resistance by incorporation of diverse genes (Pyramiding) for resistance into a single cultivar. DNA fingerprinting oilers a more detailed method to characterize strain s, populations and biotypes by direct examination of the genetic material itself .The stability of resistance in a given rice cultivar is determined by how the pest population changes and the way resistance is deployed, thus an adequate evaluation of biodiversity in the pest population becomes fundamental requirement. Biotechnology offers an excellent approach to assess the pest diversity using several DNA fingerprint ing techniques