Genetic Diversity of Chinese and Global Pea (Pisum sativum L.) Collections

Pea (Pisum sativum L.) is an important food and feed legume grown across many temperate regions of the world, especially from Asia to Europe and North America. The goal of this study was to use 30 informative pea microsatellite markers to compare genetic diversity in a global core from the USDA and a core collection from the National Genebank of China (NGC). The Chinese and global collections had 295 and 305 accessions, respectively. A total of 259 alleles were detected in the full 600 accessions, with a mean of 8.7 alleles per locus. Given the range of countries represented, the global collection was found to be more diverse than the Chinese core. However, the Chinese accessions still formed two distinct groups. The first group had 90.6% spring-planted peas from northern China. The second group had 65.9% winter-planted peas from southern China. An outlier group included wild peas from the P. sativum elatius and asiaticum subspecies. In conclusion, the USDA collection had slightly more overall diversity than the NGC collection given its global nature, but the Chinese accessions represented a considerable fraction of overall diversity, with accessions representing spring and winter pea types from northern and southern China, respectively, that are only weakly represented in the USDA core. The origin of Chinese peas is likely to be from the region of domestication in the Middle East through an ancient route of dissemination through southern Asia, where some genetically similar peas are grown.