Genetic Diversity of Loquat [Eriobotrya japonica (Thunb.) Lindl.] Native to Guizhou Province (China) and Its Potential in the Genetic Improvement of Domesticated Cultivars

Loquat is an important commercial specialty fruit tree crop in China, and as a result, there is significant interest in its genetic improvement. Wild loquat, native to China, provides a remarkable genetic resource for breeding improved varieties. Guizhou Province in southwest China contains many natural populations of loquat in its rural areas. In the present study, we analyzed the genetic diversity of native loquat growing throughout Guizhou Province together with wild relatives and domesticated loquat using a set of 20 informative SSR markers. Molecular analysis identified four gene pools, with gene pool I representing cultivated genotypes and gene pool IV containing wild relatives and native surveyed accessions. Approximately 10.8 % of the samples collected from Guizhou Province are feral forms derived from cultivated genotypes, whereas 24.9% are most closely related to wild species. The remaining 64.3 % of the gene pool is intermediate genotypes derived from spontaneous crosses between wild native forms and cultivated loquat.