Genetic and Genotype x Environment Interaction Effects for Appearance Quality of Rice

This study was conducted to generate genetic information in rice varieties based on a complete diallel crosses over two years. The results indicated that genotype effect was significant for all traits. Genotype×environment interaction effects were significant only for cooked grain length (CGL) and cooked grain shape (CGSH). General combining ability (GCA) and specific combining ability (SCA) effects were significant for entire traits, which indicated the important roles of both additive and non-additive gene actions. GCA ×environment interaction effects were significant for CGL, CGSH and grain elongation index (GEI). In the controlling of the inheritance of milled grain shape (GSH), milled grain width (MGW), GEI, milled grain length (MGL), CGSH and cooked grain width (CGW), the additive gene effects were more important than non-additive one. The average degree of dominance was within the range of partial dominance for all of the traits. The narrow-sense heritability was ranged from 0.65 (GSH) to 0.36 (CGL). GCA effects were significant for all of the parents in milled grain length and it was significant for some of the parents in other traits. The crosses of Deilmani × IRFAON-215 exhibited significant SCA for GEI. The positive mean of heterosis was observed for CGW. The highest maximum values of heterosis were revealed in GEI, flowed by GSH, MGW and CGW. GCA and MPV were significantly and positively correlated together for all traits.