新疆博乐和伊犁河谷敏麻蜥的种下分类地位探讨
Taxonomical Status of Eremias arguta from Bole City and Ili River Valley, Xinjiang Uyghur Autonomous Region, China

中文摘要：敏麻蜥 Eremias arguta是麻蜥属 Eremias在欧亚大陆分布最广的物种之一，主要栖息在欧洲东部和亚洲中部，从罗马尼亚到蒙古国和中国西部的干旱草原和半荒漠中。先前认为敏麻蜥有6个亚种，我国分布有2个亚种，由于种群间形态变异较大，一些亚种的分类地位尚有争议。本研究采用形态比较和基于线粒体细胞色素 b基因序列的分子系统发育分析，对新疆博乐和伊犁河谷的敏麻蜥4个种群28号样本进行种下分类地位探讨。联合GenBank中的敏麻蜥细胞色素 b基因序列，采用最大简约法、最大似然法和贝叶斯推断法构建系统发育树进行亚种界定。采用贝叶斯因子，通过比较限制性和非限制性贝叶斯树的拓扑结构检验有关敏麻蜥亚种分类的几种相互竞争的假设。结果表明，博乐种群的形态特征与伊犁河谷支系一致，雄性的背侧在繁殖季节有醒目的蓝色或绿色眼点。系统进化树也表明，来自博乐的单倍型属于伊犁河谷支系，为一个尚未描述的分类群 Eremias arguta ssp.。以往有关伊犁河谷种群属于指名亚种 E. a. arguta或东方亚种 E. a. potanini或乌兹别克斯坦亚种 E. a. uzbekistanica的观点均被显著拒绝。伊犁河谷支系最有可能与乌兹别克斯坦亚种和伊塞克湖亚种 E. a. darevskii二者构成的支系形成姐妹群，但并没有强的证据拒绝备择假说，即伊犁河谷支系位于树的基础位置，与其余支系形成姐妹群。此外，重建的系统发育树中指名亚种与东方亚种形成了交互单系，尽管自展支持率很低且后验概率不高；其备择假设，即东方亚种嵌在指名亚种支系中，也没有很强的证据拒绝。总之，博乐种群不属于东方亚种，而属于一个单独的伊犁河谷支系，同时，这也是伊犁河谷支系在准噶尔盆地有分布的新纪录；伊犁河谷支系不应该被划分为指名亚种、东方亚种或乌兹别克斯坦亚种，而是属于尚未描述的新亚种；伊犁河谷支系的系统发育位置还不明确，需要采用整合分类学的方法澄清。此外，结合形态变异，本研究还讨论了东方亚种的有效性。
英文摘要：The steppe racerunner ( Eremias arguta) is one of the most widespread species of the Eurasian racerunners (genus Eremias), inhabiting steppes and semi-deserts of eastern Europe and central Asia from Romania to Mongolia and western China. Historically, 6 subspecies are recognized, and with 2 subspecies occurring in China; however, the taxonomical status of some subspecies is still controversial due in part to their high morphological variability. The present study deals with the intraspecies systematics of 28 samples representing 4 populations in Bole city and Ili River Valley, Xinjiang Uyghur Autonomous Region, China, through morphological comparison and phylogenetic analysis based on mitochondrial DNA cytochrome b ( Cyt b) gene. Cyt b gene sequences of E. arguta available in the GenBank were compiled for comparison with the obtained haplotypes. Tree-based subspecies delimitation was achieved by using maximum parsimony, maximum likelihood and Bayesian phylogenetic analyses. Bayes factors (BF) were used to test the competing hypotheses for E. arguta by comparing the unconstrained Bayesian tree topology to Bayesian trees with ‘hard’ constraints. The morphological features of steppe racerunner population in Bole city matched the description of those from the Ili River Valley, with specific dorsal pattern characterized by the presence of bright blue or green ocelli in breeding males. Phylogenetic trees congruently indicated that the haplotypes from Bole city belong to the Ili River Valley clade, which represents a separate lineage with undescribed subspecies ( E. arguta ssp.). The 3 hypotheses that populations from the Ili River Valley belong to the subspecies E.