Environmental response patterns in commercial classes of common bean (Phaseolus vulgaris L.).

The yield data of 39 cultivars of diverse commercial classes of beans (Phaseolus vulgaris L.) planted in seven locations in Michigan were subjected to cluster and canonical variate analyses. The essential findings and conclusions can be summarized as follows: (1) Cluster analysis classified the cultivars into sub-sets or clusters almost identically coinciding with their commercial class designation. Canonical variate analysis completely confirmed the sub-groupings. Within class similarities were attributed to a narrow genetic base resulting from a common genetic relationship, or at least sharing of a common gene pool. (2) It was found that two clusters could possess almost identical mean (cluster mean) yields, and deviate in opposite directions over the same range of environments. (3) When total genotype × environmental interaction variance was partitioned into between and within clusters, the cluster × environment portion constituted 80% of the total. (4) These results imply that if the behavior of a given cultivar across a series of environments is known, the behavior of all other members of the class across a similar range of environments would be predictable.