茶树苯乙醇樱草糖苷含量相关遗传位点的挖掘

Mining of Genetic Locus of Phenylethyl Alcohol Primrose Glycoside Abundance in Tea Plants

以169个茶树种质作为关联群体,利用基于简化基因组测序(genotyping-by-sequencing,GBS)技术开发的675245个高质量SNP标记在2018—2020年3个年份间,对茶树新梢中苯乙醇樱草糖苷的含量进行了全基因组关联分析(genome-wide association study,GWAS)。结果表明,不同年份茶树种质间的苯乙醇樱草糖苷的含量变异系数为61.50%~62.09%,相关系数介于0.95~0.98(P<0.01),广义遗传力为67.49%。3种GWAS分析模型共检测到24个与茶树苯乙醇樱草糖苷含量显著关联的稳定位点(P<0.001),解释表型变异率为0.01%~10.63%。进一步利用等位变异效应分析挖掘到36个具备24个主效位点优异等位变异且苯乙醇樱草糖苷含量显著升高的优异种质。初步筛选出10个与苯乙醇樱草糖苷含量相关的候选基因,分别为TEA020086.1、TEA003248.1、TEA013029.1、TEA021435.1、TEA016196.1、TEA029411.1、TEA014564.1、TEA014567.1、TEA014571.1和TEA014573.1,这些基因主要涉及茶树次生代谢与转录调控分子过程。

In this study,169 tea germplasms were used as the association population,and 675245 high-quality SNP markers developed based on the simplified genome sequencing technology were used to perform genome-wide association study(GWAS)on the content of phenylethanol primrose glycosides in tea shoots from 2018 to 2020.The results demonstrated that the variation coefficient of phenylethanol primrose glycoside content among tea germplasms in different years was 61.50%–62.09%,the correlation coefficient was 0.95–0.98(P<0.01),and the generalized heritability was 67.49%.Three GWAS analysis models detected a total of 24 stable sites(P<0.001)which significantly associated with phenylethanol primrose glycosides in tea plants,explaining phenotypic variation rates ranging from 0.01%to 10.63%.Thirty-six excellent germplasm with excellent allelic variations at 24 major loci were identified and significantly increased phenylethanol primrose glycoside content by allelic effect analysis.A total of 10 candidate genes related to phenylethanol primrose glycoside content were preliminarily screened,namely TEA020086.1,TEA003248.1,TEA013029.1,TEA021435.1,TEA016196.1,TEA029411.1,TEA014564.1,TEA014567.1,TEA014571.1,and TEA014573.1,mainly involving secondary metabolism and transcriptional regulation molecular processes.