مطالعه نحوه توارث و برآورد پارامترهاي ژنتيكي صفات مرتبط با مقاومت به سرما در برنج در مرحله جوانه زني

Inheritance of Cold Resistance and estimation of genetic parameters in rice at the germination stage

The inheritance of cold resistance was evaluated at the germination stage in crosses between seven rice genotypes as half diallel. Analysis of variance indicated that there were highly significant differences among the genotypes, general combining ability (GCA) and specific combining ability (SCA) for percentage of reduction in radicle length (RL), percentage of reduction in plumule length (PL) and percentage of reduction in germination (GP). Significance of GCA and SCA revealed that additive and non-additive gene effects were controlled the inheritance of studied traits, but according to the higher magnitude of the dominance variance than additive variance and low value of genetic ratio showed that non-additive gene action was predominant than additive. Broad-sense heritability were 86, 68 and 81% for RL, PL and GP respectively. The assessments of GCA effects revealed that Deilamani was an ideal general combiner characters and superior variety for all Hassani was also a good general combiner for PL and GP, The degree of dominance were 1.93, 1.26 and 0.99 for RL, PL and GP respectively and indicated over-dominance of gene effects for RL and PL and dominance effects for GP.The estimates of SCA effects of top ranking crosses indicated that NedaxHassani could be regarded as the most desirable cross combination for all of three traits. In this cross SCA effect and estimated heterosis were significant and negative. Consequently crosses that Hassani and Deilamani was one of the parents, indicated desirable SCA effects for all of the traits, and could be used for breeding programes.