Abstract

In this research, F₁ and F₂ progenies of diallel crosses with eight-parental genotypes were used to investigate the mode of inheritance for earliness in safflower (Carthamus tinctorius L.). Days to emergence, days to budding, days to bolling, days to flowering and days to maturity were estimated in 64 and 28 genotypes in F₁ and F₂ generation, respectively. The results indicated that there was enough genetic variation among genotypes for diallel analysis. Also, the results indicated significant differences for general combining ability (GCA) and specific combining ability (SCA) for all evaluated traits in two generations. Except for days to maturity, reciprocal effects were significant for studied traits. Additive gene action had more importance for days to budding and days to maturity in F₁ and F₂ generation, respectively. For days to budding additive gene effects had more importance for genetic control of it. For days to emergence and days to flowering additive and dominance gene effects were important. The highest narrow-sense and broad-sense heritability were denoted to days to budding in two generations. Among parental genotypes, IL.111 and GE₆₂₉₁₈ were the best negative combiners for earliness. There was a moderate consistency in estimation of genetic parameters in two generations.

Key words: Analysis, earliness, effect, genetic, heritability, safflower.