Molecular breeding of rice for improved disease resistance, a review

Abstract

Diseases are considered to be the major limiting factors in rice production around the globe. Considering rice as an important cereal crop, developing disease resistant cultivars is a prime objective of breeders. Compared to conventional breeding, molecular breeding especially using marker assisted selection appears to be more effective and precise. The best management of disease is to bring durable wide spectrum resistance in rice cultivars. This can be accomplished by accumulating both qualitative and quantitative resistance genes in to rice cultivars. Introducing these resistance genes from the wild relatives of rice in to commercial cultivars has greatly helped the breeders to accomplish this task. Marker assisted selection is extremely valuable in resolving the issues the breeders face with traditional breeding. A number of transgenic rice lines harboring the so called ‘foreign’ resistant genes have been produced. However such promising lines must be extensively replicated in fields to evaluate stable integration and continued expression of genes. None the less identification of disease resistance genes and quantitative trait loci (QTLs), use of marker assisted selection along with gene pyramiding and transgenic approaches all provide breeders a hope to build high yielding disease resistant cultivars. Based on such premises, we can truly envision broadening of our understanding the genetic and molecular basis of disease resistance in rice.