Inconsistency between morphological traits and ancestry of individuals in the hybrid zone between two Rhododendron japonoheptamerum varieties revealed by a genotyping-by-sequencing approach
Inconsistency between morphological traits and ancestry of individuals in the hybrid zone between two Rhododendron japonoheptamerum varieties revealed by a genotyping-by-sequencing approach
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DOI：
10.1007/s11295-016-1084-x
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发表时间：
2017-02
影响因子：
2.4
通讯作者：
I. Tamaki;Watanabe Yoichi;Y. Matsuki;Y. Suyama;M. Mizuno
中科院分区：
文献类型：
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作者：
I. Tamaki;Watanabe Yoichi;Y. Matsuki;Y. Suyama;M. Mizuno
杂种区杂种个体的形态特征和遗传背景反映了该杂种区的历史。在高山杜鹃与高山杜鹃的杂交区，日本七叶菊品种京丸变种（RJK），测定了可用于区分这两个品种的花部形态特征，并取样叶片进行DNA提取。还使用了由纯RJH和RJK组成的参考群体。个体的基因型数据通过多重ISSR测序基因分型（MIG-seq）方法获得。参考群体中的RJH和RJK在形态和遗传上都有明显的分化。在所研究的杂种区中，虽然存在形态纯的RJH和RJK以及它们之间的杂种，但大多数个体，包括那些形态纯的个体，都具有来自RJH和RJK的祖先。形态性状与个体内祖先比例之间无显著相关。这些结果表明，该杂交区起源于过去的RJH和RJK之间的杂交。人口统计学模型间的模型比较结果也支持这一假设，并估计混合带建立的时间为41万年前。据认为，积累的重组随后形成的杂交区的形态性状和每个祖先基因组的分数在一个人内的不一致。
The morphological traits and genetic backgrounds of hybrid individuals in a hybrid zone reflect the history of that zone. In the hybrid zone betweenRhododendron japonoheptamerumvar.hondoense(RJH) andR. japonoheptamerumvar.kyomaruense(RJK), flower morphological traits that can be used to distinguish the two varieties were measured and leaves were sampled for DNA extraction. Reference populations consisting of pure RJH and RJK were also used. Genotype data for individuals were obtained by the multiplexed ISSR genotyping by sequencing (MIG-seq) method. RJH and RJK in the reference populations were morphologically and genetically clearly differentiated. In the hybrid zone studied, although there were morphologically pure RJH and RJK, and hybrids between them, most individuals, including those that were morphologically pure, had ancestries from both RJH and RJK. There were no significant correlations between morphological traits and the proportion of ancestry within an individual. These results suggest that this hybrid zone originated from the hybridization between the RJH and RJK in the past. The result of model comparison among population demographic models also supported this hypothesis, and the time when the hybrid zone was established was estimated to be 410,000 years ago. It is considered that accumulation of recombinations subsequent to the formation of the hybrid zone contributed to the inconsistency between the morphological traits and the fraction of each ancestral genome within an individual.