Natural variation for fertile triploid F1 hybrid formation in allohexaploid wheat speciation
Natural variation for fertile triploid F1 hybrid formation in allohexaploid wheat speciation
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DOI：
10.1007/s00122-007-0584-3
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发表时间：
2007-08-01
影响因子：
5.4
通讯作者：
Kawahara, Taihachi
中科院分区：
文献类型：
--
作者：
Matsuoka, Yoshihiro;Takumi, Shigeo;Kawahara, Taihachi
异源多倍体物种形成的克里思，模式和地理的影响自然变化的能力，父母种表达合子后生殖表型，影响杂种育性。为了阐明这种自然变异的影响，我们使用异源六倍体普通小麦的进化作为模型，并分析了参与三倍体F1与四倍体小麦（Triticum turgidum）杂交的异常和育性表达的节节麦（二倍体祖先）种质的地理和系统发育分布。植物杂交实验和叶绿体DNA为基础的进化分析表明，杂交abnormalitycausing加入有限的地理和系统发育分布，表明这些物种之间的合子后杂交障碍是欠发达。与此相反，加入涉及可育的三倍体F1杂种形成具有广泛的地理和系统发育分布，表明一个深刻的进化起源。广泛分布的杂交种支持T。aestivum的物种形成发生在多个地点内的物种范围的Ae。tauschii，其中现有的条件使自然杂交与T turgidum。我们的研究结果的影响如何自然变异的能力，Ae。tauschii表达合子后生殖表型的多样性，并对tauschii的物种形成有贡献。Aestivum进行了讨论。
The tempo, mode, and geography of allopolyploid speciation are influenced by natural variation in the ability of parental species to express postzygotic reproductive phenotypes that affect hybrid fertility. To shed light on the impact of such natural variations, we used allohexaploid Triticum aestivum wheats' evolution as a model and analyzed the geographic and phylogenetic distributions of Aegilops tauschii (diploid progenitor) accessions involved in the expression of abnormality and fertility in triploid F, hybrids with Triticum turgidum (tetraploid progenitor). Artificial-cross experiments and chloroplast-DNA-based evolutionary analyses showed that hybrid-abnormalitycausing accessions had limited geographic and phylogenetic distributions, indicative that postzygotic hybridization barriers are underdeveloped between these species. In contrast, accessions that are involved with fertile triploid F, hybrid formation have wide geographic and phylogenetic distributions, indicative of a deep evolutionary origin. Wide-spread hybrid-fertilizing accessions support the theory that T. aestivum speciation occurred at multiple sites within the species range of Ae. tauschii, in which existing conditions enabled natural hybridization with T turgidum. Implications of our findings on how natural variation in the ability of Ae. tauschii to express those postzygotic reproductive phenotypes diversified and contributed to the speciation of T. aestivum are discussed.