Molecular screening of rice (Oryza sativa L.) genotypes for submergence tolerance

Abstract

Rice (Oryza sativa L.) is one of the most consumed staple food crops, providing food to about half of the world population. Submergence stress is an important constraint in rice cultivation faced by rice growers globally. In Kerala condition, flood prone areas like Kuttanad, Pokkali, as well as low lying paddy fields are mainly affected by submergence. Sub1 is the major quantitative trait locus (QTL) that confers submergence tolerance to rice genotypes. Earlier researchers have already identified the presence of Sub1 gene in rice varieties showing submergence tolerance. Such rice genotypes are characterized by a higher survival rates and better yield even after 2 weeks of submergence stress. The advancement of marker assisted selection (MAS) have a striking impact on developing improved Sub1 varieties which can meet the increasing demand for submergence tolerant varieties. The present study was planned to ascertain the rice genotypes having submergence tolerance by in vitro phenotyping followed by marker assisted selection. Genotypes KAUM 7 and KAUM 19 showed a better survival rates than other test genotypes during in vitro phenotyping. Among the ten genotypes evaluated for submergence tolerance with the help of SSR markers, KAUM 7 and KAUM 19 were identified with Sub1 QTL. Besides, this finding lays the foundation for further researches on breeding for submergence tolerance in rice.

Keywords

• o. sativa
• submergence tolerance
• sub1 qtl
• ssr marker