Phylogeography and Genetic Structure of Sand Dune Specialist Stilpnolepis centiflora (Asteraceae) in Northwest China Revealed by Molecular Data
Phylogeography and Genetic Structure of Sand Dune Specialist Stilpnolepis centiflora (Asteraceae) in Northwest China Revealed by Molecular Data
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分子数据揭示中国西北沙丘特生五花草（菊科）的系统发育地理学和遗传结构
DOI：
10.3390/d14020104
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发表时间：
2022-01
期刊：
影响因子：
--
通讯作者：
Shi XJ
中科院分区：
文献类型：
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作者：
Shi XJ
细花狗舌草是菊科一年生特有草本植物，分布于我国西北五个沙漠。本研究的目的是探讨S. centiflora和试图连接物种进化与沙漠形成在更新世时期。我们利用核基因和叶绿体基因的序列数据，研究了28个居群的遗传多样性。我们使用网络分析、分子方差空间分析（SAMOVA）和Mantel检验分析序列数据。然后，我们使用分子钟将遗传模式置于时间框架中，并使用中性测试和确定错配分布来测试扩张信号。鉴定出6种不同的单倍型和31种核糖体型。叶绿体DNA亚群发生了显著的亚群分化（GST = 0.952; NST = 0.976），而nrDNA亚群发生了中度亚群分化（GST = 0.360; NST = 0.579）。SAMOVA揭示了四个不同的相关单倍型组，与沙漠的边界相吻合。分子年代学结果表明，代表不同沙漠的分支在1.2 ~ 0.20Ma之间发生了分化，与青藏高原隆升的昆黄运动和中晚更新世的一次冰川事件（Naynayxungla）相一致。S.不同荒漠植物区系间的亲缘关系在所考察的遗传性状上也有相应的反映，种间和荒漠间的时空演化具有一致性。因此，S.百花区系似乎是由地质运动和气候变化驱动的。这里描述的模式可能是有用的保护生物学家，并可能作为一个模式，为其他沙专性生物在中国西北部的沙漠。
Stilpnolepis centiflora is an endemic annual herb in the Asteraceae family found across five sand deserts in Northwest China. We aimed to investigate the genetic structure of S. centiflora and attempt to link species evolution with desert formation during the Pleistocene era. We used sequence data from nuclear and chloroplast genes to investigate genetic diversity among 28 populations. We analyzed sequence data using network analysis, spatial analysis of molecular variance (SAMOVA), and a Mantel test. We then used a molecular clock to place the genetic patterns in a temporal framework and tested for signals of expansion using neutrality tests and by determining mismatch distributions. Six distinct haplotypes and 31 ribotypes were identified. Significant chloroplast DNA population subdivision was detected (GST = 0.952; NST = 0.976), but only moderate nrDNA subdivision (GST = 0.360; NST = 0.579) was detected. SAMOVA revealed four diverging groups of related haplotypes, coinciding with the boundaries of deserts. Molecular dating suggests that the clades representing different deserts diverged from 1.2 to 0.20 Ma, concordant with the Kun-Huang Movement of Qinghai Tibet Plateau uplift and a glacial event (Naynayxungla) during the Middle–Late Pleistocene. The disjunction of S. centiflora among different deserts was correspondingly reflected in the examined genetic traits with consistent spatiotemporal evolution between species and deserts. Therefore, the evolutionary dynamics of S. centiflora appear to have been driven by geological movement and climate change. The patterns described here are potentially useful to conservation biologists and may serve as a model for other sand-obligate organisms found in the deserts of Northwest China.