Comparison of Genetic Variability and Trait Association for Yield Contributing Traits among F2 Populations Generated from Wild Introgression Lines of Rice

Abstract

Wild introgressions play a crucial role in improving the genetic diversity of a cultivated varieties and also act as an important source for novel alleles for crop improvement. High-yielding stable backcross introgression lines identified from inter-specific crosses of Swarna cv. Oryza sativa with Oryza nivara were crossed among each other and also with parent Swarna. The F2 populations generated from 5 crosses, viz. Swarna x 166S (C1), 166S x 14S (C2), 166S x 148S (C3), 65S x 248S (C4) and 166-2S x Swarna (C5), were evaluated for 7 phenotypic traits in field conditions. Phenotypic data were analysed for genetic variability and trait association in each population individually. Descriptive statistics and correlation of yield traits in the population and the comparison among all five populations were estimated. Among the populations, C2 showed the highest average trait values for single plant yield, tiller numbers, productive tillers and harvest index. Highest range of phenotypic variation for single plant yield was also observed in C2 followed by C5; however, wide range of variation for plant height and biomass was observed in C3 and C5. Single plant yield showed significant association with all the 7 traits consistently across the populations. Plant height and biomass also showed significant variation in trait association with other traits under study. Development of mapping populations by crossing among backcross introgression lines is a useful strategy to pyramid multiple traits of interest with minimum donor introgressions.