Breeding Salt-Tolerant Rice Varieties in Puducherry (U. T.)

Salinity is the second major abiotic stress, limiting rice production worldwide and in India. Infusing salt tolerance in rice is economically and socially justifiable option to combat the menace of salinity. Nevertheless, it has to be augmented in conjunction with appropriate management practices. Complexity of the trait is manifested by its polygenic nature (quantitative), interaction with environment (soil-water-temperature-relative humidity), and ontogeny of the rice plant. Past experimental evidences indicate that salt tolerance is a multigenic trait and the components of salt tolerance in turn be determined by many genes. With the use of molecular markers, chromosomal regions associated with component physiological traits of salt tolerance (Quantitative Trait Loci, QTL) could be identified. Marker-assisted selection (MAS) offers immense hope for improvement of salt tolerance in rice, and QTL mapping studies are prerequisite for MAS that can be used to pyramid several QTLs. In Puducherry (Union Territory), salinity is caused due to both primary and secondary salinization; the latter is so critical nowadays in the first season. Considering the gravity of the menace of salt stress, various research projects were carried out to develop improved salt-tolerant rice varieties. Besides, postgraduate scholars were involved for their thesis research focusing on unraveling genetics of salt tolerance and breeding salt-tolerant varieties. We present the research findings made in the institute both by the postgraduate scholars (as part of their thesis research) and by the faculty carrying out the externally funded projects. The various aspects of the germplasm characterization/diversity analysis, genetic studies (classical and molecular), and breeding salt-tolerant varieties are presented and discussed.