Genetic Diversity in Canadian Common Bean Varieties Released Since 1930.

Genetic improvement of common bean (Phaseolus vulgaris L.) in Canada has a history of more than 120 years. Early breeding efforts, started soon after the establishment of the Central Experimental Farm in Ottawa in 1886, included testing of dry and garden bean introductions. We developed a pedigree database for bean verities of different market classes released since 1931 in Canada. The coefficient of parentage was estimated for all possible pair-wise combinations of varieties, parental and (or) ancestral genotypes. A genotypic dataset of 149 RAPD (Random Amplification of Polymorphic DNA) fragments for a sub-set of 28 bean genotypes was used to verify the results of pedigree analysis. A cluster analysis was employed to study the genetic diversity of common bean in the Canadian gene-pool. Results indicated a narrow genetic diversity among the Canadian beans of Andean-origin (kidney and cranberry), suggesting that breeding efforts for these market classes should benefit from introduction of new genetic diversity. Four genetic diversity groups were identified among the Canadian beans of middle-American origin (navy, black, pinto, pink and small-red). These included three diversity groups of navy bean varieties represented by the varieties Ex-Rico 23 (1980), Seafarer (1969), OAC Laser (1991), and a group of other middle-American classes. The latter includes a number of varieties derived from inter-market-class crosses within the middle American-origin beans. Exploiting the diversity within these four groups would broaden the genetic base of Canadian middle-American origin beans. The pedigree- and RAPD-based dendrograms were somewhat similar suggesting that pedigree information will continue to be useful to inexpensively identify diverse parents in the bean breeding programs.