Diversity distribution and population structure of tea germplasms in China revealed by EST-SSR markers |
| |
Authors: | Ming-Zhe Yao Chun-Lei Ma Ting-Ting Qiao Ji-Qiang Jin and Liang Chen |
| |
Institution: | (1) National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Sciences, 9 South Meiling Road, Hangzhou, 310008, China; |
| |
Abstract: | Tea plant (Camellia sinensis (L.) O. Kuntze) originated from China, where distributed abundant genetic resources. It is of critical importance to well
understanding of genetic diversity and population structure for effective collection, conservation, and utilization of tea
germplasms. In this study, 96 new polymorphic EST-SSR markers were developed and used to analyze 450 tea accessions collected
from 14 tea-producing regions across China. A total of 409 alleles were observed, and the gene diversity (H) and polymorphic information content (PIC) were estimated to be averagely 0.64 and 0.61, respectively, across all the tested samples. The higher level of genetic diversity
was observed in original regions like Guangxi, Yunnan, and Guizhou provinces. The allele number, H, and PIC showed decreasing trend when the region was more and more away from origin center of tea plant, which gave us implications
on the spreading route of tea plant in China. The clustering of 450 samples both showed a clear separation according to their
geographic origin based on either model simulation or genetic distance. The genetic differentiation was further analyzed among
five inferred populations represented different eco-geographic regions. The lowest F
st and the closest relationship were revealed between proximal populations, which indicated that gene exchanges occurred frequently
between nearby regions than distance ones. The majority of genetic variation resulted from differentiation within population
(81.36%) rather than among inferred (13.6%) and regional (5.04%) populations based on analysis of molecular variance. Our
study also revealed that the lower diversity and simpler population structure were found in improved cultivars than wild teas
and landraces, which indicated that genetic base of developed cultivars became narrow because of long-standing domestication
and artificial selection. So more attentions should be focused to conserve and utilize the beneficial genes in wild teas and
landraces to broaden genetic variation of new cultivars in future breeding of the tea plant. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|