Genetic Improvement of Rice for Salt Tolerance

Soil salinity and sodicity caused by occurrence of excessive salts pose daunting challenge for crop cultivation. Among various crops, rice (Oryza sativa) is the befitting crop for cultivation under salt affected conditions due to its inherent adaptive advantages. Moreover, rice has huge social and economic importance due its ability to feed a sizeable part of global population especially in Asia. Among various management options to augment crop productivity under salt stressed soils, harnessing the intra-specific genetic variation in the form of salt tolerant varieties is the most simple, economic and eco-friendly approach. In this context, considerable progress has been made for development and deployment of successful and salt tolerant varieties especially through conventional breeding tools. These scientific achievements and leads came up through investments in multi-disciplinary research and institutional networking which was enabled by various national and international funding agencies. Rice is genomically the most explored cultivated crop. Though salt tolerance is a polygenically controlled trait, scientific leads have been attained in mapping of genes/QTLs conferring tolerance to salinity especially at seedling stage. Nevertheless, mapping the genomic regions conferring agronomic advantages at adult stages are the most sought after and potential targets for genetic improvement of rice for saline and sodic environments in future. The prevalence of biotic stresses and other mineral deficiencies/toxicities are also the associated problems in salt affected areas. Therefore, harnessing the synergy of modern genomic, gene editing and phenomics technologies can lead to the evolution of robust and multiple stress tolerant rice varieties. In this regard, research investments through multi-disciplinary and institutional partnerships can bring about better livelihood, economic and environmental security from the salt affected regions.