Genetic diversity in pod and seed quality traits of common bean populations from northwestern Spain

Common bean (Phaseolus vulgaris L.) is an important food in the northwest of Spain where it is consumed as either green pods or dry seeds after cooking. Quality properties play a major role in cultivar acceptance by processors and consumers. To determine if sufficient variation in important culinary and nutritional traits exists within common bean, fifty-nine populations (plus five commercial cultivars) were grown in the northwest of the Iberian Peninsula in three different environments and evaluated for sixteen fresh pod and dry seed quality traits. Populations showed significant differences for pod curvature, length/width and width/thickness ratios of pod and seed, pod and seed texture, volume, hardness, seed coat percentage and water absorption of seed, crude protein, crude fat, crude fiber, toal sugars and starch content. Genotype × environment interaction was significant for fresh pod traits such as curvature, length/width and width/thickness ratios, and texture, and for dry seed traits such as length/width and width/thickness ratios, volume, hardness and water absorption. Estimates of heritabilities and constancies (genotypic/environmental variance) were higher than 0.5 and 1.0 respectively for pod curvature, length/width and width/thickness ratios of pod and seed, seed volume and seed water absorption. There were high correlations of pod texture with seed length/width and width-thickness ratios, seed coat percentage, seed water absorption, crude fat, total sugars, starch content and crude fiber. Pod texture could be used as an important parameter for evaluating both seed culinary and nutritional quality. In addition, 17 populations showed promise as parental material in a breeding program for pod and seed culinary quality and protein content. The culinary and nutritional quality potential of the accessions such as PHA-0171, PHA-0253 and PHA-0257 which are known as Alubias de riñón could be the base material in a breeding program to obtain accessions with a good seed quality.