基于SSR标记构建宝巾花品种的分子指纹

Using the SSR fluorescent labling to establish SSR fingerprint for 131 cultivars in Bougainvillea (Nyctaginaceae)

【目的】针对宝巾花(Bougainvillea)品种繁多、同物异名和同名异物多有发生的现象,利用可靠的分子标记技术进行品种的有效分类。【方法】基于15个简单重复序列(SSR)位点,利用荧光标记的引物对131个宝巾花品种进行PCR扩增,扩增产物经毛细管电泳检测,分析品种多样性和遗传距离,并构建品种聚类图和指纹图谱。【结果】15个SSR位点共扩增出85个等位基因,平均每个位点的等位片段数5.60个,Shannon’s信息指数、观测杂合度和期望杂合度的变化范围分别为0.38~1.53、0.11~0.94和0.16~0.73,平均值分别为1.04、0.50和0.57,位点的多态性信息量介于0.15~0.69之间,平均0.51。宝巾花品种的遗传距离为0.00~0.65,平均0.33;聚类分析表明,同一种的品种大多数聚在一类,但同一个种仍有品种未聚在一类或亚类,也有多个种的品种聚在一类;有多对品种存在同物异名或同名异物的现象;基于11个位点可有效鉴别131个品种,建立了各品种的分子指纹图谱。【结论】对同物异名或同名异物的品种,需要进一步确认品种中文名或拉丁名;基于SSR标记的宝巾花品种的指纹图谱为宝巾花品种登记、注册和知识产权保护提供了可靠技术,也为品种鉴定提供了有效手段。

【Objective】 Find a reliable molecular marker to identify Bougainvillea cultivars that are difficult to distinguish, due to cultivar richness and cultivar homonymy and synonymy. 【Method】 A total of 15 simple sequence repeats(SSR) markers were used to amplify DNA samples from 131 Bougainvillea cultivars. SSR amplicons were detected by a capillary electrophoresis method. Cultivar polymorphism and genetic distance were calculated;they were used for clustering analysis and fingerprint construction of all the 131 cultivars.【Result】A total of 85 different alleles were collectively generated by the 15 SSR loci, averaging 5.60 alleles per locus. Shannon’s information index, observed heterozygosity value, and expected heterozygosity value ranged from 0.38 to 1.53, 0.11 to 0.94 and 0.16 to 0.73, with an average of 1.04, 0.50 and 0.57 per locus, respectively. The polymorphism information content ranged from 0.15 to 0.69, with an average of 0.51 per locus. The genetic distance between cultivars ranged from 0.00 to 0.65, with an average of 0.33. Clustering analysis showed that most of the cultivars within a species tended to fall in the same cluster, but some cultivars of the same, whereas certain cultivars from different species were grouped in the same cluster. Several pairs of cultivars were either homonyms or synonyms. Only 11 SSR loci were shown to be effective for identifying the 131 cultivars;thus, the molecular fingerprints of all these cultivars were constructed based on allelic combinations of the 11 markers. 【Conclusion】Further research should be conducted to verify either the Chinese or Latin names of some suspicious cultivars. SSR-based fingerprints of Bougainvillea cultivars constitute a reliable technique for cultivar identification, registration, and intellectual property protection as well as for cultivar clarification in production practices.