Molecular approaches for selection and identification of blast resistance genes in rice

Abstract

As the population is increasing day by day, there is a need to increase the food grain production especially rice. So, it is a need to increase the yield and also to minimize the yield loss caused by various diseases and insect pests. Among the diseases of rice, Blast (caused by Magnaporthe oryzae) is the major cause for reduction of rice yield ie., about 30 to 35%. It can infect rice plant right from seedlings to adult plant stages affecting leaves, nodes, collar, panicles and roots. Many management practices such as chemical control, biological control, disease forecasting and conventional breeding can be adopted to overcome the loss due to blast disease but, they solely can’t control it because of high labour cost and more time consumption. To overcome these problems, Blast resistance genetics in rice is getting strengthened these days because of the progress in the molecular marker development and functional genomics. By using molecular breeding, the identification of R genes with the help of biotechnological/molecular tools will be helpful in modern plant breeding to improve blast resistance and its durability. Marker-assisted selection (MAS) and conventional breeding together have facilitated R genes to be combined (or ‘pyramided’) in elite rice varieties. This paper contains overviews of R genes of blast pathogen and molecular approaches for their identification, selection and management.