Quantitative genetic studies of yield, yield components, and phenological and agronomic characters in spring faba bean

Hayman's diallel cross analysis was employed to investigate the nature of the genetic control and heritability of yield, yield components, and phenological and agronomic characters in F1 and F2 generations of spring faba beans (Vicia faba L.). High-yielding S4 inbred lines from five open-pollinated faba bean cultivars were used as parents to generate complete F1 and F2 diallels. The S5 inbred line parents and the 20 cross combinations were planted in randomized complete block experiments with six replications. All characters in the F1 diallel and in the F2 diallel with the exception of days from planting to maturity met all of the assumptions required for Hayman's diallel analysis. Yield, total dry matter, harvest index, and pods per plant exhibited significant apparent overdominance in both the F1 and F2 diallels. It is concluded that substantial immediate increases in yield and total dry matter could be expected from exploiting the apparent overdominant gene action found for these characters in these crosses via F1 hybrids or synthetics. Key words: total dry matter, harvest index, diallel crosses, inheritance, Vicia faba L.