Morphological and agronomic traits of a wild population and an improved cultivar of common bean (Phaseolus vulgavis L)

Through the process of domestication, bean varieties have been selected from their wild ancestors for various anthropocentrically-important characteristics. In order to compare some agronomic and morphological traits of a wild population and a modern variety (cv. Bayo Mecentral), the following variables were evaluated: growth habit; number of nodes on the main stem; number of branches and pods per plant; flower and pod colours; stem length; days to initiation of flowering; days to physiological maturity and duration of flowering. Variation in each trait was recorded, particularly in the wild population. The growth habits of the wild population were very diverse and there were positive and significant correlations between 13 pairs of variables, including the number of nodes on the main seem, pods per plant, days to flowering and duration of flowering, whereas domesticated beans gave only a few significant correlations. The analysis of principal components indicated that the linear combination of agronomic and morphological variables, involving the first three principal components, accounted for 70% of the total variability of the data, and the populations were clearly separated as two biological entities by the first principal component. This study confirms that the process of domestication has acted to reduce variation in a range of characters. (C) 1997 Annals of Botany Company.