Genomics-based approaches to improve abiotic stress tolerance in plants: Present status and future prospects

Abstract

Abiotic stresses such as drought, salinity, flooding, and heat stress adversely impact crop productivity worldwide. Intense research efforts have been directed toward developing crop varieties tolerant to individual as well as multiple abiotic stresses. Conventional breeding approaches have resulted in the development of such tolerant crop genotypes. However, with the advent of modern approaches of genomics and genome-wide association mapping, the conventional breeding can be fast-tracked through the process of trait mapping, causal gene identification, gene discovery, and genomic breeding. More recently, new plant-breeding techniques, such as genome editing has revolutionized crop engineering in a precise and targeted fashion and has accelerated the process of genetic improvement of crops with diverse traits including abiotic stress tolerance. In this chapter, we describe the advances in genomics-assisted improvement of crop species by highlighting key milestones and techniques such as plant genome sequencing, strategies for identification of superior alleles/haplotypes from germplasm collections, generating genomic resources for use in new plant-breeding techniques such as genomics-assisted breeding and genome editing for improving abiotic stress tolerance of major crops.