基于SSR荧光标记的花果兼用梅遗传多样性分析和分子身份证构建

Genetic diversity and molecular identity of Prunus mume with both ornamental and edible values based on fluorescence-labeled simple sequence repeat (SSR) markers

摘要:

为了收集、鉴定、评价和创新花果兼用梅(Prunus mume)优良种质，推动我国北方地区梅产业链的改造升级，对花果兼用梅(Prunus mume)种质进行遗传多样性分析，构建DNA分子身份证数据库，本研究以河北省邢台68份花果兼用梅为材料，采用多态性好、条带清晰、重复性好的13对简单重复序列(simple sequence repeat,SSR)引物标记，对其进行遗传多样性分析并构建供试样品的DNA分子身份证。基于遗传距离进行非加权组平均法(unweighted pair-group method with arithmetic means,UPGMA)聚类分析，基于贝叶斯模型解析68份种质的遗传结构。结果表明，13对SSR引物共扩增到124个等位基因，平均等位基因数(number of alleles,Na)为9.538 5，等位基因频率(major allele frequency, MAF)为0.369 3，有效等位基因(number of effective alleles,Ne)为4.483 5，Shannon信息指数(Shannon genetic diversity index,I)为1.712 4。Nei’s基因多样性指数(Nei’s gene diversity index,H)为0.763 7，观测杂合度(observed heterozygosity,Ho)为0.719 5，而期望杂合度(expected heterozygosity,He)为0.769 3，平均多态信息含量(polymorphism information content,PIC)为0.733 6，平均遗传相似性系数(genetic similarity,GS)为0.772 9，表明所研究的花果兼用梅种质之间具有显著的遗传差异和丰富的遗传多样性。聚类分析将68份材料划分为3个类群，平均遗传距离(genetic distance,GD)为0.622 6。Structure群体结构分析将供试材料分为2个种群。根据引物的多态性信息含量高低选择引物组合，构建花果兼用梅种质区分需要的最少引物组合。本研究为花果兼用梅品种创新和产业升级及其园林应用和提高育种效率提供了理论依据。

关键词:梅;花果兼用;遗传多样性;简单重复序列荧光标记;分子身份证

Abstract:

We studied the genetic diversity and established the DNA molecular identify for Prunus mume with both ornamental and edible values, aiming to collect, identify, evaluate, and breed new varities of this plant and promote the upgrading of the P. mume industry chain in northern China. We employed 13 pairs of primers with good polymorphism, clear bands, and good repeatability to analyze the genetic diversity and establish the molecular identify of 68 germplasm accessions of P. mume with both ornamental and edible values from Xingtai, Hebei Province. We then employed the unweighted pair-group method with arithmetic means (UPGMA) to perform the cluster analysis based on genetic distance. After that, we analyzed the genetic structure of the 68 germplasm accessions based on a Bayesian model. The 13 pairs of SSR primers amplified a total of 124 alleles from 68 P. mume germplasm accessions, with the mean number of alleles (Na) of 9.538 5, the minor allele frequency (MAF) of 0.369 3, the mean number of effective alleles (Ne) of 4.483 5, and the mean Shannon genetic diversity index (I) of 1.712 4. The mean Nei’s gene diversity index (H) of 0.763 7, the mean observed heterozygosity (Ho) of 0.719 5, the mean expected heterozygosity (He) of 0.769 3, the mean polymorphism information content (PIC) of 0.733 6, and the mean genetic similarity (GS) of 0.772 9 suggested that there were significant genetic differences and rich genetic diversity among the studied P. mume germplasm accessions. The cluster analysis revealed that the 68 accessions were classified into three groups, with the mean genetic distance of 0.622 6. The population structure analysis classified the germplasm accessions into two populations. According to the PIC of primers, we selected primers for combination and constructed the combination with the fewest primers required for germplasm differentiation of P. mume with both ornamental and edible values. This study provides a theoretical basis for the innovation and industrial upgrading of P.mume with both ornamental and edible values in gardening and the improvement of breeding efficiency.

Key words:Prunus mume;with both ornamental and edible values;genetic diversity;fluorescence-labeled simple sequence repeat (SSR) molecular marker;molecular identity