基因组SSR应用于铁皮、迭鞘和金钗石斛种内的遗传分析

Intraspecific Genetic Analysis of D.catenatum,D.denneanum and D.nobile by Genome-wide SSR

为了探讨基因组简单重复序列(SSR)在石斛种内遗传分析中的应用价值,本研究从铁皮石斛全基因组SSR位点中随机选择了50个设计特异性引物。利用聚合酶链式反应(PCR)和聚丙烯酰胺凝胶(PAGE)电泳分析方法,分别在铁皮石斛、迭鞘石斛和金钗石斛中鉴定出17个、15个和14个SSR标记,其中7对SSR标记这三种石斛种内均具有良好多态性。结果显示,在各32份石斛种内材料间,这些SSR标记的平均多态性条带(average polymorphic bands,APD)数大多大于10,多态信息含量(polymorphism information content,PIC)也几乎均大于0.5。铁皮石斛种内SSR标记的平均APD值为13.18,平均PIC值为0.584;迭鞘石斛种内SSR标记的平均APD值为12.22,平均PIC值为0.540;金钗石斛种内SSR标记的平均APD值为15.20,平均PIC值为0.555。进一步聚类分析发现,基于SSR标记条带差异的基因型分型结果与石斛种内材料的表型差异存在一定的相关性。这些结果表明基因组SSR标记在不同石斛种间具有较好的转移性,在不同石斛种内均具有良好的多态性,且可用于与表型性状等进行相关性分析,将有助于促进石斛的遗传研究和分子辅助育种,值得进一步地开发和利用。

To investigate the application value of genome-wide simple repeat sequence(SSR)in intraspecific Dendrobium,50 locus-specific primer pairs were randomly designed from the Dendrobium candidum genomic SSR loci in this study.Using polymerase chain reaction(PCR)and polyacrylamide gel electrophoresis(PAGE)methods,17,15 and 14 SSR markers were identified in D.candidum,D.denneanum and D.nobile,respectively.And 7 pairs of them showed good polymorphism in all of the three Dendrobium species.The results showed that the average polymorphic bands(APDs)of these SSR markers were mostly more than 10,and the polymorphism information content(PIC)was almost more than 0.5 among each of 32 materials in the three Dendrobium species.The average APD and PIC values of SSR markers in D.candidum were 13.18 and 0.584 respectively,and that of SSR markers in D.denneanum was 12.22 and 0.540,respectively.The average APD and PIC values of SSR markers in D.nobile were15.20 and 0.555 respectively.Further clustering analysis revealed that the genotyping results based on SSR marker bands were correlated with the phenotypic variances in intraspecific Dendrobium.These results indicate that the genomic SSR markers provided good interspecific transferability and intraspecific polymorphism across different Dendrobium speices.They also can be used for correlation analysis with phenotypic traits.This will be beneficial for genetic research and molecular marker-assisted breeding of Dendrobium,and worthy for further development and utilization.