Abstract

Rice (Oryza sativa L.) is a medium salt-resistant crop. The present study determined the inheritance of salinity tolerance at germination stage by complete diallel crosses between six rice genotypes. Analysis of variance indicated that there were significant differences among the genotypes and specific combining ability (SCA) for all of the traits contain reduction in radicle length (RL, %), reduction in coleoptile length (PR, %), reduction in germination percentage (GP, %) and reduction in germination rate (GR, %). General combining ability (GCA) was significant for GP and RL. The reciprocal (REC) and maternal (MAT) effects were significant for GP, RL and PL.Non-maternal effect (NONMAT) were significant only for RL and PL. The significant GCA and SCA indicated the role of additive and non-additive gene actions. The higher magnitude of dominance variances showed that non-additive gene action was predominant to additive one. The perusal of GCA effects reveals that Shahpasand was an ideal general combiner for GP and RL, whereas IRFAON-215 was a good general combiner for CL. The estimates of SCA effects of crosses indicated that Shahpasand × Sepidrod and Hassani × IRFAON-215 could be regarded as the most desirable cross combination for GP and RL, respectively.

Key words: Combining ability, heterosis, salinity, rice, germination.

Abbreviation

Abbreviations: SCA, Specific combining ability; GCA, General combining ability;MAT, Maternal effects; NONM, Non-maternal effects; REC, Reciprocal effects; RL,Reduction in radicle length; PR, Reduction in coleoptile length; GP, Reduction in germination percentage; GR, Reduction in germination rate; SH,  Shahpasand; H,Hassani; SP, Sepidrod; N, Neda; SA, Saleh; IR, IRFAON-215; σ²D, Dominance variance; σ²A, Additive variance; σ²s, SCA variance; σ²g, GCA variance; DH, Degree of dominance; h²n, Narrow-sense heritability; h²b, Broad-sense heritability.