Genetics of Drought Tolerance, Mapping QTLs, Candidate Genes and Their Utilization in Rice Improvement

Abstract

Drought is one of the major challenges in sustaining crop production worldwide with impending risks due to climate change. Rice, a semi-aquatic crop that feeds majority of the global population will be severely stricken by drought stress. Adaptation to drought varies significantly in rice, which is under the regulatory control of several genes involved in several pathways. Most of these genes contribute little to the adaptation process, making it one of the most complex biological mechanisms. Identification of these adaptation genes is the prime target to enable breeding for drought tolerance in rice. Several genes and quantitative trait loci (QTLs) have already been reported in rice associated with traits related to drought tolerance, most of which are identified from landraces as well as in the wild relatives adapted to water limited environments. Recent development in phenotyping and genomic tools has opened up newer vistas of investigation on drought adaptation in rice. This has helped in development and release of improved cultivars with inbuilt tolerance to drought. This chapter summarizes the developments in understanding drought tolerance, its genetics, the underlying mechanisms and efforts for breeding drought tolerant rice cultivars.