枳属种质遗传多样性及其与近缘属植物亲缘关系的SSR和cpSSR分析

Genetic Diversity of Poncirus and Its Phylogenetic Relationships with Relatives as Revealed by Nuclear and Chloroplast SSR

应用核基因组SSR和叶绿体基因组SSR,分析了枳属28份枳及枳杂种种质的遗传多样性及其与近缘属植物的亲缘关系。核基因组SSR分析表明普通枳的遗传差异明显,22个SSR位点的平均多态性信息含量(PIC)为0.51,平均期望杂合度为0.52,表明中国枳种质资源具有较丰富的遗传多样性。在遗传距离约0.16时,22份普通枳可以分成4个类型。叶绿体基因组SSR分析则发现普通枳间基本无差异,表明以母系遗传为特征的枳叶绿体基因组相对保守。富民枳与普通枳无论是在核基因组还是在叶绿体基因组上均存在较大差异,支持富民枳种的地位。SSR和cpSSR结合使用可比较准确地鉴定枳杂种。

Twenty-eight accessions of trifoliate orange （Poncirus trifoliata Raf. ）, hybrids and seven accessions of its relatives, were analyzed for genetic diversity and phylogenetic relationship using nuclear and chloroplast SSR markers. Average PIC （polymorphism information content） value of 0. 51 and average expected heterozygosity of 0.52 were given according to nuclear SSR results. Twenty-two common trifohate orange accessions could be divided into four groups with a genetic distance of 0. 16. It indicates a rich genetic diversity of China trifoliate orange germplasm, cpSSR revealed no difference among common trifoliate orange accessions which indicates a relatively conservative chloroplast genome. Four cpSSR loci were found different between Fumin （P. polyandra S. Q. Ding et al. ） and common trifoliate orange. Fumin trifoliate orange is genetically distant from common trifoliate orange, from its hybrids as well as relatives. Therefore it could be regarded as a true species. The combined application of nuclear and chloroplast SSR could serve a more accu- rate way to identify trifoliate orange hybrids.