贵州省主要栽培茶树品种指纹图谱构建与遗传结构分析

Fingerprinting Construction and Genetic Structure Analysis of the Main Cultivated Tea Varieties in Guizhou Province

贵州是中国目前茶树种植面积最大的省份,同时也拥有丰富的茶树种质资源。对品种真实性以及遗传结构的准确鉴定是种质识别以及杂交亲本选配的关键。本研究以包含贵州省内主要栽培品种和新选育品系的54份茶树资源为材料,利用35对SSR引物进行遗传鉴定,共检测到317个等位基因位点,多态信息含量介于0.22～0.92之间,平均0.73;利用PI和PIsibs两个参数评估了每对引物的鉴别力,表明任意两对引物组合都能够区分本研究中的茶树材料,并从中筛选出5对核心引物构建了54份材料的指纹识别图谱,这5对核心引物组合足够用于更大群体的个体鉴定。利用GBS方法对54份材料进行了全基因组SNP挖掘,共鉴定到698117个高质量SNP;基于SNP进一步进行系统进化分析、主成分分析以及遗传结构分析,54份材料被划分为4个类群,育成品种与新选育品系间遗传背景呈现高度重叠;并据此推测出了前期贵州茶树育种的一般模式,表明贵州前期茶树育种过多依赖福鼎大白茶以及云南地方种质资源,预示着在后续育种实践中,加大对省外优良品种以及贵州省内古茶树资源的杂交利用力度,将有助于茶树种质创新以及新品种的选育。

Guizhou has the largest tea planting area in China,which also has the abundant tea plant germplasm resources.Accurate identification of the authenticity and genetic structure of the cultivars is the pivotal to germplasms identification and parents selection in hybridized breeding.In this study,54 tea plant germplasms including the cultivars or improved cultivars in Guizhou province were used as materials,the genetic identification of them was conducted using 35 SSR markers,firstly.A total of 317 alleles were detected,yielding the polymorphic information content(PIC)ranged from 0.22 to 0.92,with a mean value of 0.73.The genetic differentiation of each SSR marker was evaluated by PI and PIsibs,which showed that any two pairs of primers could distinguish the tea plant germplasms in this study.Five core SSR markers were selected to generate the fingerprinting of these tea plant resources,which provided the resolution sufficient for identification of the individuals in larger groups.Additionally,by using the genotyping-by-sequencing(GBS)approach,the genomewide SNP were identified with the 54 cultivars or improved cultivars,and a total of 698117 high quality SNP were identified.The phylogenetic analysis,principle component analysis(PCA)and genetic structure analysis of the 54 tea plant samples were performed.The 54 tea plant germplasms were divided into 4 sub-populations,and the genetic backgrounds of the cultivars and the improved cultivars were highly overlapped.According to the results,the general breeding model of tea plants in Guizhou in the previous was speculated,which revealed that the germplasms utilization of early tea plants breeding in Guizhou depended too much on Fudingdabaicha and the local tea plant germplasm resources of Yunnan province,and it was also shown that increasing the hybrid utilization of the excellent tea plant cultivars in other provinces and the ancient tea plant resources in Guizhou would contribute to the germplasm innovation and the breeding of new tea plants in the subsequent breeding practice.