Marker Assisted Selection for Developing High Yielding Submergence Tolerant Rice (Oryza sativa L.) Genotypes with Slender Grain

Submergence was a major abiotic stress in rice growing areas, particularly in the rainfed low land ecosystem of eastern India. Tolerance of complete submergence was recognized in some landraces and can be conferred by the Sub1 locus in chromosome 9. Farmers' adaptation to these landraces and previously developed submergence tolerance genotypes was poor due to either their low yield potential and/or poor grain quality. The purpose of this study was introgressing Sub1 locus from tolerant genotype to high yielding susceptible cultivars with an aim of developing high yielding submergence tolerant genotypes with slender grain preferred by local consumer. During this study fifty lines were selected on the basis of higher yield potential from an advance generation (F-4) of a cross between a submergence tolerant, natural mutant (P-1) and submergence susceptible rice cultivar (IR-36). Three already established SSR Primer pairs (RM-265, RM-219 and RM-464A), linked with submergence tolerance were employed to detect polymorphism among the two parents. Only RM-219 showed polymorphism among the parents in 2% agarose gel and employed for screening advance rice lines. Seven lines showed similar banding pattern with tolerant parent and screened for their submergence tolerance ability in the field in controlled and submerged conditions along with the two parents. Out of seven, six lines performed well in submerged condition. Finally on the basis of yield performance as well as slenderness of grain two genotypes were selected which will be very useful source for development of additional submergence tolerant high yielding mega varieties with preferred grain type.