Heritabilities and phenotypic correlations of morphological traits of beans

Abstract

Indeterminate bean (Phaseolus vulgaris L.) lines derived from crosses between small-seeded indeterminate and large-seeded determinate genotypes were used for estimating the heritabilities and phenotypic correlations for seed yield and morphological traits. The F₂ generation of six bean populations was planted at the Fortuna Substation, Juana Díaz, Puerto Rico in October 1984. Seed yield per plant, number of branches per plant, plant height, node number per plant, biological yield, and apparent harvest index were measured for 50 indeterminate plants selected at random from each population. Fifty plant rows of each population were planted in February 1985 at the Fortuna Substation, and in March 1985 on a small farm in the Constanza valley of the Dominican Republic. Narrow sense heritabilities were estimated with parent-offspring regressions of the F₂ and F₃ generations, and phenotypic correlations were estimated with means of the F₃ lines. The indeterminate F₃ lines had greater plant height and fewer nodes than their indeterminate parents. Biological yields, harvest indexes and number of branches of the F₃ plants were generally equal to or less than those of their indeterminate parents. Greater branch and node number and greater plant height, biological yield, and harvest index were associated with greater seed yield. Narrow sense heritabilities (NSH) of morphological traits were generally low to intermediate. Since NSH of the morphological traits were no greater than NSH of seed yield, replicated advanced generation yield trials still appear to be the most effective approach for identifying large-seeded indeterminate bean lines with greater seed yield potential.