Evidences of introgression from cultivated rice to Oryza rufipogon (Poaceae) populations based on SSR fingerprinting:: implications for wild rice differentiation and conservation
Evidences of introgression from cultivated rice to Oryza rufipogon (Poaceae) populations based on SSR fingerprinting:: implications for wild rice differentiation and conservation
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DOI：
10.1007/s10682-006-9113-0
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发表时间：
2006-11-01
影响因子：
1.9
通讯作者：
Lu, Bao-Rong
中科院分区：
文献类型：
--
作者：
Song, Zhiping;Zhu, Weiyue;Lu, Bao-Rong
作物向野生的渗入可能在野生物种的进化中起着重要的作用。亚洲栽培稻（Oryza sativa L.）由于其与野生祖先O. rufipogon Griff的交叉相容性而受到特别关注。栽培稻和紫叶稻的分布具有广泛的同域性，特别是在亚洲，许多野生种群被稻田包围。因此，来自栽培稻的基因流可能有可能改变近距离野生稻群体的遗传组成。本研究通过对139个水稻品种（86个籼稻生态型和53个粳稻生态型）和11个稻稻稻居群的336个野生个体的分析，估算了稻稻稻稻的渗入情况。利用选取的17对水稻简单序列重复（SSR）引物进行DNA指纹图谱分析，测定了水稻品种和紫斑稻样品的等位基因频率，并通过聚类分析估计了野生稻和栽培稻之间的遗传关联。根据结构程序的混合模型，对稻株间的亲缘关系进行了检测。分析结果表明，DX-P1、DX-P2、GZ-P2和HL-P 4个野生水稻居群含有在所调查水稻品种中常见的一些罕见等位基因。另外，聚类分析结果表明，分散在水稻品种间的4个野生群体与品种的亲缘关系比其他野生群体更密切。这一发现支持了大量基因从作物流向野生物种的论点，当这些物种彼此靠近时。渐渗群体的遗传多样性略高于从水稻中分离出来的群体。作物向野生的渗透可能对野生种群的遗传变异产生累积影响，导致野生物种的显著分化。因此，应采取有效措施避免栽培稻的大量入侵，以免影响野生稻品种的有效就地保护。
Crop-to-wild introgression may play an important role in evolution of wild species. Asian cultivated rice (Oryza sativa L.) is of a particular concern because of its cross-compatibility with the wild ancestor, O. rufipogon Griff. The distribution of cultivated rice and O. rufipogon populations is extensively sympatric, particularly in Asia where many wild populations are surrounded by rice fields. Consequently, gene flow from cultivated rice may have a potential to alter genetic composition of wild rice populations in close proximity. In this study, we estimated introgression of cultivated rice with O. rufipogon based on analyses of 139 rice varieties (86 indica and 53 japonica ecotypes) and 336 wild individuals from 11 O. rufipogon populations in China. DNA fingerprinting based on 17 selected rice simple sequence repeat (SSR) primer pairs was adopted to measure allelic frequencies in rice varieties and O. rufipogon samples, and to estimate genetic associations between wild and cultivated rice through cluster analysis. We detected consanguinity of cultivated rice in O. rufipogon populations according to the admixture model of the STRUCTURE program. The analyses showedz that four wild rice populations, DX-P1, DX-P2, GZ-P2, and HL-P, contained some rare alleles that were commonly found in the rice varieties examined. In addition, the four wild rice populations that scattered among the rice varieties in the cluster analysis showed a closer affinity to the cultivars than the other wild populations. This finding supports the contention of substantial gene flow from crop to wild species when these species occur close to each other. The introgressive populations had slightly higher genetic diversity than those that were isolated from rice. Crop-to-wild introgression may have accumulative impacts on genetic variations in wild populations, leading to significant differentiation in wild species. Therefore, effective measure should be taken to avoid considerable introgression from cultivated rice, which may influence the effective in-situ conservation of wild rice species.