Assessing genetic diversity and population structure in a citrus germplasm collection utilizing simple sequence repeat markers (SSRs)
Assessing genetic diversity and population structure in a citrus germplasm collection utilizing simple sequence repeat markers (SSRs)
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DOI：
10.1007/s00122-006-0255-9
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发表时间：
2006-05-01
影响因子：
5.4
通讯作者：
Federici, Claire T.
中科院分区：
文献类型：
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作者：
Barkley, Noelle A.;Roose, Mikeal L.;Federici, Claire T.
使用 24 个简单序列重复 (SSR) 标记来检测来自加州大学河滨分校保存的柑橘种质收集的 370 个主要有性来源的柑橘种质之间的分子多态性。共检测到275个等位基因，平均每个位点11.5个等位基因，平均多态性信息含量为0.625。计算每个单独的 SSR 标记、整个种群和特定柑橘类群的遗传多样性统计数据。通过构建邻接树来确定所有柑橘种质和推定的非杂交柑橘种质之间的系统发育关系。当从数据集中删除混合类群时，在物种层面上得到了对单系性的强烈支持。这两棵树表明金柑属于柑橘属，但枳属是柑橘的姐妹属。此外，如果柑橘种质的基因型表明通过基于模型的聚类方法混合，则将柑橘种质概率分配给种群或多个种群。这种方法确定了该数据集中的五个群体。这些单独的分析（基于距离和模型）都支持这样的假设：只有少数天然存在的柑橘品种，而大多数其他类型的柑橘是通过这些天然存在形式之间的各种杂交事件产生的。
Twenty-four simple sequence repeat (SSR) markers were used to detect molecular polymorphisms among 370 mostly sexually derived Citrus accessions from the collection of citrus germplasm maintained at the University of California, Riverside. A total of 275 alleles were detected with an average of 11.5 alleles per locus and an average polymorphism information content of 0.625. Genetic diversity statistics were calculated for each individual SSR marker, the entire population, and for specified Citrus groups. Phylogenetic relationships among all citrus accessions and putative non-hybrid Citrus accessions were determined by constructing neighbor-joining trees. There was strong support for monophyly at the species level when hybrid taxa were removed from the data set. Both of these trees indicate that Fortunella clusters within the genus Citrus but Poncirus is a sister genus to Citrus. Additionally, Citrus accessions were probabilistically assigned to populations or multiple populations if their genotype indicated an admixture by a model-based clustering approach. This approach identified five populations in this data set. These separate analyses (distance and model based) both support the hypothesis that there are only a few naturally occurring species of Citrus and most other types of Citrus arose through various hybridization events between these naturally occurring forms.