The Qinghai-Tibetan Plateau (QTP) and adjacent areas are centres of diversity for several alpine groups. Although it is known that the QTP acted as a source area for diversification of the alpine genus Gentiana, the evolutionary processes underlying diversity in this genus, especially the formation of narrow endemics, are still poorly understood. Hybridization has been proposed as a driver of plant endemism in the QTP but few cases have been documented with genetic data. Here, we describe a new endemic species in Gentiana section Cruciata as G. hoae sp. nov., and explore its evolutionary history with complete plastid genomes and nuclear ribosomal internal transcribed spacer sequence data. Genetic divergence within G. hoae ~3 million years ago was followed by postglacial expansion on the QTP, suggesting Pleistocene glaciations as a key factor shaping the population history of G. hoae. Furthermore, a mismatch between plastid and nuclear data suggest that G. hoae participated in historical hybridization, while population sequencing show this species continues to hybridize with the co-occurring congener G. straminea in three locations. Our results indicate that hybridization may be a common process in the evolution of Gentiana and may be widespread among recently diverged taxa of the QTP.

中文翻译：

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反复杂交是青藏高原龙胆（龙胆科）新奇进化的基础

青藏高原（QTP）和邻近地区是几个高山群体的多样性中心。尽管已知QTP充当了根特属（Gentiana）高山植物多样化的来源地区，但对该种多样性的潜在进化过程，尤其是狭窄地方病的形成，仍知之甚少。杂交已被提出作为QTP中植物特有性的驱动力，但很少有遗传数据记录在案。在这里，我们将Gentiana部分Cruciata中的新特有物种描述为G. hoae sp。十一月，并用完整的质体基因组和核糖体内部转录的间隔区序列数据探索其进化历史。内部遗传差异约300万年前的G. hoae继而在QTP上进行了冰期后扩张，这表明更新世冰川是影响G. hoae人口历史的关键因素。此外，质和核数据之间的不匹配表明，G. hoae参与历史杂交，而人口测序表明这一物种继续同现同类杂交麻花艽在三个地点。我们的结果表明，杂交可能是龙胆属植物进化中的一个常见过程，并且可能在QTP最近分化的类群中广泛传播。