PDF(Pubmed)
Abstract：
Amynthas aspergillum (Perrier, 1872), a natural resource used in traditional Chinese medicine (Guang-dilong) with high economic value, is widely distributed in forests and farmland habitats in the hilly areas of southern China. To investigate the extent of genetic differentiation and diversity in A. aspergillum, a population genetic structure study was performed on 157 samples from 75 locations in southern China using the mitochondrial genes COI, COII, 12S rRNA, 16S rRNA, and NDI. The results indicated that A. aspergillum had a high level of genetic diversity, and variation within populations was the main source of the total variation. Six deeply divergent mitochondrial clades (I-VI) were detected using both phylogenetic tree and haplotype network analyses. This finding was supported by the high Kimura two-parameter genetic distance and the pairwise fixation index value obtained based on the COI gene. No significant phylogeographic structures were observed. The widespread geographic distribution of clades II, IV, and VI suggested a recent demographic expansion based on multiple analysis results. These results include a high level of Hd and low π, star-shaped haplotype network structures with a high number of less frequent haplotypes, significantly negative neutrality test values, and a unimodal mismatch distribution pattern. The divergence time estimates and reconstruction of the ancestral area revealed that A. aspergillum originated in Guangxi Province and underwent initial intraspecific diversification in the early Pliocene to generate clade I. Then, it gradually dispersed eastward and rapidly differentiated into clades II-V during the Pleistocene. The Yunnan-Guizhou Plateau and Nanling and Wuyi Mountains might act as geographical barriers for the spread of A. aspergillum to the west and north.
摘要：
紫菜（Perrier，1872),一种用于中药（广迪龙）的自然资源，具有很高的经济价值，在中国南方丘陵地区的森林和农田生境中广泛分布。研究曲霉菌的遗传分化程度和多样性，使用线粒体基因COI对来自中国南方75个地点的157个样本进行了群体遗传结构研究，COII,12SrRNA，16SrRNA,和NDI。结果表明曲霉菌具有较高的遗传多样性,种群内的变异是总变异的主要来源。使用系统发育树和单倍型网络分析检测到六个深度不同的线粒体进化枝（I-VI）。这一发现得到了高木村两参数遗传距离和基于COI基因获得的成对固定指数值的支持。未观察到明显的系统地理结构。分支II的广泛地理分布，IV,和VI根据多重分析结果提出了最近的人口扩张。这些结果包括高水平的Hd和低的π，星形单倍型网络结构，具有大量较低频率的单倍型，显著为负的中性测试值，和单峰失配分布模式。祖先区的发散时间估计和重建表明，曲霉菌起源于广西，并在上新世早期经历了最初的种内多样化，产生了进化枝I。在更新世期间，它逐渐向东分散并迅速分化为II-V进化枝。云贵高原，南岭和武夷山可能成为曲霉向西部和北部传播的地理屏障。
