genetic diversity of a worldwide alfalfa collection

The dataset is composed with 400 cultivated accessions (378 cultivars and 22 landraces) whose fall dormancy was mainly between 3 and 7. Their origin, based on the place they have been collected (landraces) or initially selected and registered (cultivars) was Europe (318 accessions), North America (45 accessions), South America (16 accessions), China (17 accessions), Middle East (3 accessions) and Japan (1 accession). In addition, 617 accessions representing advanced breeding material obtained by five European breeders were included. All the 1017 accessions were genotyped and used for genetic structure study while only the 400 genetic resources were phenotyped for phenology and used for GWAS and GS studies. Genotyping data : Each accession was represented by 100 plants, the DNA extraction was performed from a pool of 100 leaflets, each taken on a plant. The GBS on alfalfa has been conducted with the couple of enzymes PstI-MseI to obtain a sufficient number of markers while reducing the number of missing values considering the number of sequences per accession.