Valentin Ivanov KOSEV
Institute of Forage Crops–Pleven, Gen. Vladimir Vazov 89 street, 5800 Pleven, BULGARIA; e–mail: email@example.com
Abstract: The inheritance and gene effects structure were investigated for ten quantitative traits in field cultivars by a full diallel model of four parents–the cultivars Kerpo, Pleven 10, Mir and EFB33. Over dominance was prevalent for most of the traits in both hybrid generations (F1 and F2) except for 1000–seed weights. A non–additive gene action appeared to be more predominant for the inheritance of most traits studied. The fraction of h2/H2 indicated that at least one group of genes controlled dominance for all the traits, namely for seed weight per plant (6), seeds per pod (3). The Н2/4Н1 ratio was close to the expected value of 0.25 for seeds per plant and seed weight per plant, indicating a symmetrical distribution of dominant and recessive genes. Dominant alleles were more frequent in parental forms for the inheritance of most traits except seeds per pod in F1. In the case of seeds per pod (F1) and 1000–seed weight (F1 and F2) a comparatively low difference was established between the coefficient of heritability in narrowand broad sense, indicating that the selection in early generations may be effective. The genotypes with exhibited dominant alleles were EFB33 for plant height, first pod height, internode distance and fertile nodes per plant, Mir for pods per plant, nodes per plant and 1000–seed weight and Pleven 10 for seeds per plant and seed weight per plant. Kerpo had recessive alleles for all the tested traits except seeds per pod.
Key words: breeding, field pea, gene effects, genetic analysis, inheritance