Genome scans for divergent selection in natural populations of the widespread hardwood species Eucalyptus grandis (Myrtaceae)using microsatellites

2018-11-23 本站

题目：Genome scans for divergent selection in natural populations of the widespread hardwood species Eucalyptus grandis (Myrtaceae)using microsatellites

期刊：Scientific Reports 

作者：Zhijiao Song1,2,3,Miaomiao Zhang2,4, Fagen Li2,Qijie Weng2, Chanpin Zhou2, Mei Li2, Jie Li2, Huanhua Huang5, Xiaoyong Moa4, and Siming Ganb1,2

单位：1.Academy of Forestry, Xiangshan Road, Beijing 100091, China; 2.Key Laboratory of State Forestry Administration on Tropical Forestry Research, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Longdong, Guangzhou 510520, China; 3.Baoshan University, Yuanzheng Road, Baoshan 678000, China;  4.College of Forestry, South China Agricultural University, 284 Block, Wushan Street, Guangzhou 510642, China;5.Guangdong Academy of Forestry, Longdong, Guangzhou 510520, China

摘要：  Identification of loci or genes under natural selection is important for both understanding the 美高梅 basis of local adaptation and practical applications, and genome scans provide a powerful means for such identification purposes. In this study, genome-wide simple sequence repeats markers (SSRs) were used to scan for molecular footprints of divergent selection in Eucalyptus grandis, a hardwood species occurring widely in costal areas from 32° S to 16° S in Australia. High population diversity levels and weak population structure were detected with putatively neutral genomic SSRs. Using three FST outlier detection methods, a total of 58 outlying SSRs were collectively identified as loci under divergent selection against three non-correlated climatic variables, namely, mean annual temperature, isothermality and annual precipitation. Using a spatial analysis method, nine significant associations were revealed between FST outlier allele frequencies and climatic variables, involving seven alleles from five SSR loci. Of the five significant SSRs, two (EUCeSSR1044 and Embra394) contained alleles of putative genes with known functional importance for response to climatic factors. Our study presents critical information on the population diversity and structure of the important woody species E. grandis and provides insight into the adaptive responses of perennial trees to climatic variations.