基于SSR标记的百合资源遗传背景分析

Genetic background of lily germplasm resources based on SSR markers

摘要:

为研究百合(Lilium spp.)种质资源的遗传背景，精准评价和筛选优异种质用于百合的遗传改良，本研究采用简单序列重复(simple sequence repeat, SSR)分子标记技术对来自我国11个省份的62份百合种质资源进行了遗传背景分析。结果表明，83对百合SSR引物中有15对引物具有多态性，共扩增出157个等位基因位点，每个位点的等位基因数为5-19个，平均每个位点有效等位基因数(number of effective alleles, Ne)为4.162 8，平均观测杂合度(observed heterozygosity, Ho)和平均期望杂合度(expected heterozygosity, He)分别为0.228 2和0.694 1，平均多态性信息含量(polymorphism information content, PIC)为0.678 8，平均Nei’s多样性指数(Nei’s diversity index, H)和平均Shannon信息指数(Shannon’s information index, I)分别为0.694 1和1.594 9，说明供试百合种质遗传多样性丰富。利用非加权配对算术平均法(unweighted pair group method with arithmetic mean, UPGMA)进行聚类分析，可将62份种质分为5大类，主成分分析将材料分为3个类群，结合两种分析发现各类群存在一定地理相关性，绝大数来源相同的百合种质可聚为一类。群体结构分析将百合群体划分为4个类群和1个混合类群。上述研究结果为百合种质资源的精准鉴定和育种利用提供了一定的理论依据和基因资源。

Abstract:

To study the genetic background of lily (Lilium spp.) germplasm resources, and accurately evaluate and select excellent germplasm for genetic improvement of lily, we analyzed the genetic background of 62 lily germplasm accessions from 11 provinces of China by using simple sequence repeat (SSR) molecular markers. The results showed that 15 out of 83 pairs of lily SSR primers were polymorphic. A total of 157 allelic loci were amplified, with the number of alleles per locus ranging from 5 to 19 and the average number of effective alleles per locus being 4.162 8. The average observed heterozygosity and expected heterozygosity were 0.228 2 and 0.694 1, respectively. The average polymorphic information content was 0.678 8. The average Nei’s diversity index and Shannon's information index were 0.694 1 and 1.594 9, respectively, indicating that the tested lily germplasm had high genetic diversity. The 62 germplasm accessions were classified into 5 groups by the unweighted pair group method with arithmetic mean (UPGMA) and into 3 groups by the principal component analysis. The two analyses revealed a geographic correlation among different groups. The majority of lily germplasm accessions from the same source tended to cluster together. The population structure analysis classified the lily accessions into 4 populations and 1 mixed population. The above results provide a theoretical basis and genetic resources for the precise identification and breeding of lily germplasm resources.