Genetic Diversity Of Germplasm Resources On Phaseolus Vulgaris

Sixty varieties of phaseolus vulgaris were collected in this study, including 43 from Heilongjiang Province, 13 from The Center of International Agriculture Tropic and 4 from Poland, which were classified as 35 for vine, 12 for dwarf and 13 for semi-wild varieties. This study was to analyze the genetic similarity and genetic distance in population and among populations of the 60 varieties and to draw the dendrogram of cluster analysis by using the markers of morphology, allozyme and RAPD.I .The botanical and biological characters of the 60 phaseolus vulgaris varieties were measured. The range of the Oushi distance among the varieties was 0.11-0.985, calculated by the normalization of standard derivation and our own computer program. Based on the analysis of genetic relationship of the dendrogram, the 60 phaseolus vulgaris varieties could be classified into two types, one for dwarf variety, and one for the vine and semi-wild varieties. The morphological marker was an easy way for classification.2. The analysis on 10 enzyme systems was done for the 60 varieties and 25 locies were obtained. The ratio of polymorphic loci was 0.16. The average genetic distance was 0.0568. By using the average genetic distance, the 60 varieties could be divided into 8 groups, 5 for vine, 2 for dwarf, and 2 for semi-wild variety. The genetic distance of vine variety was relatively far, suggesting its importance for storing germplasm resource as breeding materials.3. Genomic DNA was extracted from young leaves of 60 phaseolus vulgaris using a modified SDS method. 314 repeatable loci were detected through the use of 29 selected primers. The ratio of polymorphic loci was 0.854, of which 0.958 for vine, 0.733 for dwarf and 0.573 for semi-wild variety. The polymorphic loci for vine variety was the strongest among the 60 varieties.4.The genetic diversity of phaseolus vulgaris was mainly distributed in vine population according to the measurement of Shannon index and Nei index. Among the population of phaseolus vulgaris studied so far, the level of genetic diversity for 3 populations was as follows, vine> dwarf> semi-wild. The average genetic similarity in population and among populations was 0.8053 and 0.75 14, respectively. The genetic distance in population and among populations was 0.1947 and 0.2419, respectively. Among the total 314 bands amplified, therewere 10 bands specifically for vine variety, 1 for dwarf variety and 1 for semi-wild variety, suggesting a high level of genetic variation in vine variety.5.Total 60 varieties in this study could be classified into 4 groups for vine population, 2 for dwarf population and 2 for semi-wild population based on the analysis of the dendrogram of cluster analysis for the markers of morphology, allozyme and RAPD.6.It is of importance to collect phaseolus vulgaris resources from home and abroad since Heilongjiang province is the main area for breeding and cultivating phaseolus vulgaris in China. The stepwise analysis for the markers of morphology, allozyme and RAPD would be beneficial for investigating the genetic background of phaseolus vulgaris in population and among populations and for identifying the inter-relationship in population. The present study would be valuable for preserving the germplasm and breeding good strains of phaseolus vulgaris in Heilongjiang province.