四川茶树资源遗传多样性及高EGCG资源筛选

Genetic Diversity of Tea Resources and Screening High EGCG Germplasms in Sichuan Province

为促进四川茶树资源评价与茶树特异资源鉴定,本文利用11对SSR引物对109份四川茶树资源进行了遗传多样性和亲缘关系分析,并对其夏梢的茶多酚含量及儿茶素组分进行分析测定。结果表明:11对SSR引物共扩增出35个观测等位基因,遗传多态信息量(PIC)、Nei’s多态性指数及Shannon信息指数的平均值分别为0.58、0.58、0.98。将109份种质资源聚为7个类群,在分子水平上具有较大差异性,材料来源地间遗传距离与地理距离不存在显著的相关性。同时对茶多酚及儿茶素组分进行分析,109份材料夏梢的茶多酚为(21.59%±0.25%)^(30.56%±0.72%)(平均25.17%±1.87%),儿茶素为21.82%~25.04%(平均23.29%),酯型儿茶素为17.91%~22.08%(平均19.46%),EGCG为9.71%~16.24%(平均13.86%)。结果显示,四川茶树资源遗传背景较复杂,遗传基础较宽且差异较大,具有丰富的遗传多样性。从中筛选出一批特异资源材料,其中高儿茶素资源8份(>19%),高酯型儿茶素资源10份(>15%),高EGCG资源14份(>13%),超高EGCG资源的5份(>15%)。为核心茶树资源圃建设及高EGCG资源鉴定评价提供理论依据。

In order to protect and exploit tea specific resources in Sichuan Province,11 simple sequence repeat(SSR)primers were used to determine the genetic polymorphism and genetic relationship among 109 tea germplasms,and the contents of tea catechins and total polyphenols in summer tea shoots were analyzed.SSR analysis showed that a total of 35 alleles were amplified.The average value of polymorphism information content(PIC),Nei’s polymorphism index(H)and Shannon information index(I)was 0.58,0.58 and 0.98,respectively.109 germplasm resources were divided into seven groups,which showing great differences at the molecular level.There was no obvious correlation between genetic and geographical distance among the material resources.At the same time,the components of tea polyphenols and catechins in 109 germplasm resources were analyzed.The total contents of tea polyphenols,catechin,ester-catechin and epigallocatechin gallate ranged from 21.59%±0.25%to 30.56%±0.72%,21.82%to 25.04%,17.91%to 22.08%,and 9.71%to 16.24%,respectively.The average value was 25.17%±1.87%,23.29%,19.46%and 13.86%,respectively.These results showed that tea genetic diversity was rich in Sichuan.Those genetic backgrounds were complex,and the genetic basis of variation was large.A series of specific genetic resource were screened out,including eight high catechin resources (more than 19%), ten high ester catechin resources (more than 15%), 14 high EGCG resources (more than13%), and five high EGCG resources (more than 15%). These results would provide a theoretical basis for constructingtea tree nursery and evaluating high EGCG resources.