Inheritance of Some Quantitative Characters in Pigeonpeas (Cajanus cajan (L.) Mill sp.)

Abstract

Three varieties and an irradiation-derived line of pigeonpeas were used as parents in five crosses as follows: P.I. 5690 X Kaki, P.I. 5690 X Saragateado, P.I. 5690 X 526, Kald X 526, and Saragateado X 526. The F₂, F₃ and parents of each cross were planted in the field at the Isabela Substation during 1966-67 in a randomized block design with three replicates. Genotypic variability was studied and genotypic and phenotypic correlations were calculated for all the crosses in the F₂ and F₃ generations. Genetic coefficients of variation and heritability estimates were computed for four traits in five crosses and for six traits in one particular cross. Frequency distributions are shown for date of flowering, plant height, and seed weight. There was much greater variation for all crosses, in general, in seed weight, plant height, and flowering date than in number of seeds per pod. With the exception of number of pods per plant the correlations between seed yield and other traits were not great enough to provide reliable indications for yield. The phenotypic and genotypic correlations between seed yield and number of pods per plant were high, above 0.90. However, their low heritability, 45.3 and 52.1 percent in F₂ and F₃ generations, tends to indicate that not too much progress could be expected for seed yield improvement by selecting for large number of pods per plant. Good progress by selection could be made by breeders in traits such as flowering date, plant height, and seed weight which showed high heritability values.