Molecular markers based approaches to drought tolerance.

Drought stress is one of the most serious yield-reducing stresses in agriculture. Understanding the genetic basis of traits that can practically contribute towards development of drought resistant varieties is of paramount importance. This review focuses on the utilities of the chosen morpho-physiological traits in determining drought tolerance and provides an overview of molecular markers and genomics approaches that are available to increase the efficiency of breeding of these traits in crop breeding programmes. Suitable examples are cited where marker assisted selection (MAS) methods have started to prove useful in breeding for increased drought tolerance. Applications of model and non-model genomes in identifying functional markers associated with quantitative trait loci (QTLs), genes, and their allelic variants contributing to drought tolerance are highlighted. Genetics, genomics and molecular biology methods are also discussed for fine mapping and cloning of major QTLs as well as of their applications in developing more robust and affordable tools and technologies.