Inferring the Phylogeny and Divergence of Chinese Curcuma (Zingiberaceae) in the Hengduan Mountains of the Qinghai-Tibet Plateau by Reduced Representation Sequencing

Clarifying the genetic relationship and divergence among Curcuma L. (Zingiberaceae) species around the world is intractable, especially among the species located in China. In this study, Reduced Representation Sequencing (RRS), as one of the next generation sequences, has been applied to infer large scale genotyping of major Chinese Curcuma species which present little differentiation of morphological characteristics and genetic traits. The 1295 high-quality SNPs (reduced-filtered SNPs) were chosen from 997,988 SNPs of which were detected from the cleaned 437,061 loci by RRS to investigate the phylogeny and divergence among eight major Curcuma species locate in the Hengduan Mountains of the Qinghai-Tibet Plateau (QTP) in China. The results showed that all the population individuals were clustered together within species, and species were obviously separated; the clustering results were recovered in PCA (Principal Component Analysis); the phylogeny was (((((C. Phaeocaulis, C. yunnanensis), C. kwangsiensis), (C. amarissima, C. sichuanensis)), C. longa), (C. wenyujin, C. aromatica)); Curcuma in China originated around similar to 7.45 Mya (Million years ago) in the Miocene, and interspecific divergence appeared at ca. 4-2 Mya, which might be sped up rapidly along with the third intense uplift of QTP.