Genetic diversity and breeding history of Winter Mushroom (Flammulina velutipes) in China uncovered by genomic SSR markers.

Flammulina velutipes is one of the most widely cultivated mushroom species in China. However, its genetic background remains poorly understood due to the limited sampling and poor molecular markers used. In this study, 124 F. velutipes strains were employed, including 110 cultivars and 14 wild strains, and 25 new SSR markers were developed based on the genome of F. velutipes. A total of 153 alleles were detected in 124 strains to investigate the improper cultivar naming, genetic diversity and breeding history of F. velutipes in China. Our fingerprinting analyses indicated that 65 strains can be differentiated from the total of 124 strains, and over 53% of the strains are labeled with improper commercial names. The genetic diversities of wild strains are higher than those of the cultivars, suggesting that wild strains may harbor a large "arsenal" gene pool in nature available for strain breeding. The white cultivars in China were originally introduced from Japan, while the yellow cultivars were directly domesticated from wild strains isolated from southeastern China or hybridized between the white cultivars and yellow strains.