Seasonal and Genotypic Effects on Yield and Physico-chemical Seed Characteristics Related to Food Quality in Dry, Edible Beans

Abstract

Abstract The yields and physico-chemical seed traits related to food quality of 25 strains of dry beans (Phaseolus vulgaris L.) representative of the Black Turtle Soup commercial class were evaluated for 3 seasons. The strains differed significantly over seasons for washed drained weight, textural properties, and surface color characteristics of cooked seeds. All the other traits were nonsignificant in the combined analysis. Trait expression was strongly influenced by genotype × season interactions. Spearman's coefficient of rank correlation between pairs of years indicated that the interactions were due primarily to inconsistent strain rankings from year-to-year. The season and genotype × season variance component estimates for yield, soaking, and several cooked bean traits were larger than the genotypic component, indicating that seasonal effects predominated over genotypic effects. These results suggested that several years of testing are needed to assess strain performance accurately for food quality. The contribution made by each strain to the genotype × season variance component was ascertained by calculating a “stability variance” statistic. Based on this statistic, strains were found to differ in their genetic potential to respond to varying environments. Several genotypes were phenotypically stable for most traits. Strain no. 23 (CIAT pedigree FF 4-13-M-M-M-M), which had good yield (2.8 MT/ha) and protein percentage (27.7%) and favorable culinary quality, was of particular interest.