Combining Ability for Seed Yield and Its Components in Common Bean of Andean Origin

Abstract

Knowledge of parental combining ability is essential for creating useful genetic variation through hybridization. Our objectives were to examine combining ability for yield and its components for large‐seeded common bean (Phaseolus vulgaris L.) of Andean origin and to test an earlier observation that germplasms from Middle American races Durango and Jalisco possess positive general combining ability (GCA) for seed yield. Sixty‐four parents from different races and gene pools were randomly assigned to groups of 16. Within a group, eight parents were randomly chosen as females, the rest as males, and crossed in a Design II mating scheme. The resulting 256 F2 populations were evaluated in a reps‐in‐sets design with two replications at Palmira and Popayán, Colombia, in 1989. The experimental unit was a four‐row plot, 5 m long. The GCA effects using line × tester analysis were measured for seed yield (kg ha−1), pods per square meter, seeds per square meter, 100‐seed weight (g), and days to maturity. Mean squares due to males and females (vs. those for males × females) were larger in magnitude and significant (P < 0.05) for all traits; the smaller mean squares for males × females were significant only for seed weight and days to maturity. Mean yields of populations between races Durango and Jalisco were the highest, while populations between races Chile and Nueva Granada were the lowest. Populations between races Chile and Durango had the next‐lowest yields. Positive GCA effects were found for yield (19 parents), seed weight (6 of the 19), seeds per square meter (20), pods per square meter (19), and days to maturity (29). Negative GCA was found for days to maturity (25 parents).