Evaluation of Phenotypic Diversity in Ecotypes of alfalfa (Medicago sativa) from Iran

To determine the phenotypic diversity, eighty one ecotypes of Medicago sativa, collected from different areas of Iran, were evaluated. High variation was observed among ecotypes for all the evaluated characteristic. Results of correlation coefficient among traits indicated that the role of stem in forage yield is more pronounced than that of the leaf. Also the correlation between the "ratio of leaf to stem" and "wet forage yield" was observed as negative and significant. Therefore, the components most affecting forage quantity are plant height and stem weight. By Principal Components Analysis (PCA), the first three principal components with eigen values of more than 1 contributed 89.71% of the variability among the ecotypes. PC1 was positively correlated with leaf fresh weight, stem fresh weight, leaf dry weight and stem dry weight. The traits with the biggest values on PC2 were leaf/stem ratio of fresh weight and leaf/stem ratio (dry weight), whereas PC3 was positively correlated with plant height, and negatively with the 10% flowering date. The ecotypes were grouped into three clusters using cluster analysis. Clusters were clearly separated from each other by specific characteristics. Ecotypes obtained in this study, provide useful information for collection management and make these genetic resources more accessible to breeders