Tragopogon dubius : Multiple introductions to North America and the formation of the New World tetraploids
Tragopogon dubius : Multiple introductions to North America and the formation of the New World tetraploids
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Tragopogon dubius : 多次引入北美和新大陆四倍体的形成
DOI：
10.1002/tax.12743
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发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
Soltis, Pamela S.
中科院分区：
文献类型：
--
作者：
Soltis, Douglas E.;Mavrodiev, Evgeny V.;Gitzendanner, Matthew A.;Alexeev, Yuri E.;Godden, Grant T.;Soltis, Pamela S.
黄芪（菊科）是研究全基因组复制的进化模型，最近有两个重复形成的异源多倍体，Tragopogon mirus和T. miscellus，以及许多其他的多倍体物种。Tragopogon mirus和T. miscellus是在欧洲引入三个二倍体后在北美西部形成的：T. pyrrifolius和T. pratensis。在这些二倍体中，T. bastarus是两个四倍体的共同亲本，并且在欧亚大陆广泛分布。由于人类介导的洲际引入可能导致与当地物种杂交，以及相关的多倍化，因此从欧洲到北美的T. arcus的引入历史提供了进一步的机会来研究植物引入的程度和后果。使用ITS序列数据，我们表明，形态多样，广泛定义的T. arabus包括一个复杂的至少10个不同的ITS类型在其原生范围内，其中6个已从欧洲引入到北美。值得注意的是，尽管这两个异源四倍体物种各自在从局部到区域的地理范围内多次形成，但反复形成是仅涉及其中一种ITS亚型的重复杂交的结果。这些结果加强了早期的数据表明，不是所有的二倍体基因型可以形成异源多倍体。传统上被认为是T. P. S.l.的一部分。现在被认为是不同的物种（例如，T. lainzii），很可能这里鉴定的其他不同的ITS基因型也可能标志着最终值得作为单独物种识别的独特谱系。然而，更深入的系统发育分析，涉及更多的样本，从整个地理范围ofT. cancerus是必要的，因为是详细的评估分类，形态学和细胞学。
Tragopogon(Asteraceae) is an evolutionary model for the study of whole‐genome duplication, with two recently and repeatedly formed allopolyploids,T. mirusandT. miscellus, and many additional polyploid species.Tragopogon mirusandT. miscellusformed in western North America following the introduction of three diploids from Europe:T. dubius,T. porrifolius, andT. pratensis. Of these diploids,T. dubiusis a shared parent of both tetraploids and is broadly defined and widely distributed in Eurasia. Because human‐mediated intercontinental introductions may lead to hybridization with local species, and associated polyploidization, the introduction history ofT. dubiusfrom Europe to North America provides further opportunity to investigate both the extent and consequences of plant introductions. Using ITS sequence data, we show that the morphologically diverse, broadly definedT. dubiuscomprises a complex of at least 10 different ITS types in its native range, six of which have been introduced from Europe into North America. Significantly, although the two allotetraploid species have each formed multiple times on geographical scales from local to regional, recurrent formation is the result of repeated hybridization involving only one of these ITS subtypes. These results reinforce earlier data suggesting that not all diploid genotypes can form allopolyploids. Several entities traditionally considered part ofT. dubius s.l. are now recognized as distinct species (e.g.,T. lainzii), and it is likely that other distinct ITS genotypes identified here may also mark unique lineages that ultimately merit recognition as separate species. However, more intensive phylogenetic analyses involving many more samples from across the geographic range ofT. dubiusare required, as are detailed assessments of taxonomy, morphology, and cytology.