ISHS Acta Horticulturae 546: International Symposium on Molecular Markers for Characterizing Genotypes and Identifying Cultivars in Horticulture
ASSESSING COMMON BEAN GENETIC DIVERSITY USING RFLP, DAMD-PCR, ISSR, RAPD AND AFLP MARKERS |
| Authors: | I. Métais, C. Aubry, B. Hamon, R. Jalouzot, D. Peltier |
| Keywords: | Phaseolus vulgaris, polymorphism, molecular markers, dendrogram, germplasm |
| Abstract:
We have evaluated the effectiveness of RFLP, DAMD-PCR, ISSR, RAPD and AFLP markers in assessing polymorphism and relationships between 24 lines of Phaseolus vulgaris L. Fourteen of these commercial lines come from European breeders and ten from North American creators. We have used a Phaseolus specific minisatellite sequence as a probe that allow to fingerprint 23 of the bean lines tested showing 94% of polymorphic bands. Based on the sequence information, primers corresponding to the bean specific minisatellite core sequence were used in PCR amplifications. Our observations suggest that the DAMD-PCR was sensitive in detecting genetic variation between bean species and between accessions of P. vulgaris. Moreover, we show that the DAMD-PCR alone may be limited in its ability to detect genetic variation among cultivated bean lines due to the low number of loci amplified by the DAMD-PCR. Only one out of the five ISSR primers tested was efficient in generating multiple band profiles which didn’t allow to distinguish all the different bean lines. Reproducible RAPD profiles were obtained to differentiate all the genotypes tested with only seven primers. The level of polymorphism was higher (66%) than those obtained with the three other techniques DAMD-PCR (40%), ISSR (60%) and AFLP (29%). Finally, only RFLP and RAPD provide us enough information to deal with analyses of bean lines relationships. The second purpose of the study was to explore the genetic diversity among bean cultivars. Band profiles generated by RFLP or RAPD were compiled onto a data matrix on the basis of the presence (1) or absence (0) of selected bands. Dendrograms were constructed by UPGMA cluster analysis from a Jaccard dissimilarity index using PHYLIP 4.0. Both analyses led to the same clustering of the bean lines according to geographical origins (United States or Europe). The dendrogram drawn from RAPD data clusters the European lines coming from the same breeder. It appears that the structuration of the lines could be related to each breeder genetic resources. | |
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