Exploring Stable Low Soil Phosphorous Stress Tolerance in Rice Using Novel Allele Recombination From <scp><i>Oryza rufipogon</i></scp>

ABSTRACT Advent of changing climatic conditions along with nutrient deficient soils adversely affects the environment for the rice production. Wild introgression lines derived from KMR3 and Oryza rufipogon population were evaluated in six environments, including optimum and low phosphorus stress condition. Significant differences among the introgression lines were observed for plant height, tiller number, biomass, grain yield per plant, days to 50% flowering and harvest index across the environments. Based on grain yield observed under optimum phosphorus and limited phosphorus (P stress condition), eight stress tolerance indices were calculated and found STI and GMP are the better indices to discriminate among tolerant and susceptible genotypes, and correlation studies also confirmed the significant association between STI and GMP. Cluster analysis based on stress tolerance indices revealed three different clusters distinguishing genotypes based on their stable performance on yield related traits. AMMI and GGE biplot analysis to identify the stable performance across environments revealed NSR60, NSR101, NSR105, NSR85 and NSR86 as high grain yielders, whereas NSR135, NSR5 and NSR88 as stable performers. WAASBY‐based stability analysis on multiple traits (MTSI) showed NSR135, NSR79 and NSR18 with lowest MTSI, indicating their high stability and high mean performance compared with parent KMR3. Further genotyping for low P tolerance gene ( PSTOL1 ) and grain yield genes ( Gn1a , SPIKE , TGW6 , DEP1 and OsSPL14 ) using allele specific markers showed that the desirable alleles of SPIKE , Gn1a and TGW6 were derived from wild parent O. rufipogon . Low P tolerance allele PSTOL1 was absent in recurrent parent KMR3; however, the introgression lines harboured desirable alleles, which were derived from O. rufipogon . Further mapping studies will help to identify a significant potential QTLs/gene for low P tolerance from O. rufipogon . Wild introgression lines, NSR85, NSR124, NSR80, NSR54, NSR86 and NSR88, were found as the high yielding and nutrient stress tolerant genotypes, which can be used as potential donors in future breeding programmes for low P stress tolerance.