Genetic Analysis for Grain Yield and its Components of some New Rice Restorer Lines in Early Generations

Abstract

The present investigation was carried out at the experimental farm of Rice Research Department, Sakha Agriculture Research Station, FCRI, ARC, Egypt, during three seasons of 2016, 2017 and 2018. To assess the genetic parameters and phenotypic correlation coefficients for the studied traits of promising restorer lines had earliness and high yielding during F3 and F4 generations in hybrid rice program. Twenty populations used for each two crosses IR69625A x Giza 178R and G46A x Giza 178R evaluated in F3 and F4 generations. Seventy five plants divided to five groups for each population. F3 and F4 generations showed highlysignificant and positive variation among populations for the studied traits during two seasons. The means values for the studied traits in F4 population were higher than of F3 populations except days to heading, indicating the effectiveness of selection for these traits. The two crosses combinations recorded high heritability coupled with high genetic advance as percent of mean indicating to the presence of non- additive gene action in both populations. There were positive and significant associations between grain yield and the studied traits of all populations in both generations, indicated that, selections for seed set % and grain yield were effective in later generations. It could be concluded the presence of genetic diversity for two generations for the studied traits, high heritability in broad sense which indicated that genotypic variance effect play an important role in inheritance of these traits for developing new plant types using as a restorer lines in hybrid rice program.