RFLP Evaluation of Nine Medicago Accessions Representing the Original Germplasm Sources for North American Alfalfa Cultivars

All alfalfa (Medicago sativa L.) cultivars grown in North America originate from nine germplasm sources introduced into the USA from different geographic regions. Nine accessions representing the original germplasm sources have been developed; however, the level of genetic diversity within and among these accessions is not known. Genetic diversity of these accessions was estimated by screening DNAs from 12 individuals of each accession, along with bulked samples containing equal amounts of DNA from 4, 6, or all 12 individuals, for nuclear RFLPs revealed by hybridization to 35 cloned alfalfa sequences. One hundred and eighty restriction fragments were scored as present or absent across all individuals from all accessions, and genetic similarity estimates (GSEs) of all pair-wise comparisons were calculated from these data