Correlation between the phenotypic variation of alfalfa pods and pod splitting

Twelve pod morphological indicators were monitored in a homogeneous garden using 24 exotic wild Medicago falcata germplasm. The analysis of morphological diversity (coefficient of variation) showed that nine pod phenotypic indicators showed large differences between different germplasms. The largest variation was observed in pod coat (57.74%), followed by that in pod colour (54.92%) and pods (52.81%). The results of the principal component analysis showed that the nine pod traits could be transformed into four principal components with a cumulative contribution of 72.79%, representing the majority of the information in the original data. Cluster analysis divided the 24 M. falcata germplasm into four groups, Class I was the most abundant, with 11 germplasm resources, accounting for 45.83%. This taxon is characterized by long semi-circular pods with dark brown color, the highest number of seeds per pod, good traits and great breeding potential; Class II has 4 germplasm resources, accounting for 16.67%, and the pods are mostly sickle-shaped and easy to split; Class III has 8 germplasm resources, accounting for 33.33%, and Class IV has only 1 material, of which No. 16 is curved to a large extent and difficult to split, which can be used for anti-dehiscent pods. The material can be used for breeding.