Parental Polymorphic Survey between Rice Varieties (Oryza sativa L.) for Phosphorus Starvation Tolerance Gene by Using SSR Markers

Abstract

Insufficient soil phosphorus has been the most important factor affecting rice yield under the rice grown conditions. KMR-3R is a popular restorer line used for commercial rice hybrids production. For majority of the rice ecosystems, most of the rice hybrids released using three line systems were suited for normal phosphorus conditions only which exhibits severe yield reduction under low phosphorus conditions. To facilitate the efficient use of complex polygenic traits in hybrid rice, molecular breeding approaches were developed using KMR-3R BILs with Pup1 QTL by introgression of major QTL Pup1 controlling genes yield under low phosphorus stress. Parental polymorphic survey is a pre requisite before starting marker assisted backcrossing, it is used for introgression of a desirable traits from a donor genotype into a recipient genotype. In this context, I have screened all reported SSR primers linked to low phosphorus tolerance and observed K-46-1 and K-46-2 linked to Pup1 QTL was polymorphic between Kasalath and KMR-3R. Simultaneously I have screened 300 full-genotype SSR markers covering entire genome and observed 86 SSR primers as polymorphic between Kasalath and KMR-3R. After polymorphic survey, I have evaluated Kasalath and KMR-3R.under low phosphorus stress and normal phosphorus conditions and recorded significant differences among the parents. Kasalath performed well when compared to KMR-3R for all the characters studied under low phosphorus stress conditions. With the generated genotypic data, a linkage map can be constructed which will further ensues the identification of a new markers linked to low phosphorus stress.