Nie Liyun, Fang Yuhan, Xia Zengqiang, Wei Xueying, Wu Zhiqiang, Yan Yuehong, Wang Faguo
Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China.
Plants (Basel). 2024 Jul 20;13(14):1987. doi: 10.3390/plants13141987.
Species identification and phylogenetic relationship clarification are fundamental goals in species delimitation. However, these tasks pose challenges when based on morphologies, geographic distribution, and genomic data. Previously, two species of the fern genus , × and were described based on morphological traits; they are phylogenetically intertwined with and fail to form monophyletic groups. To address the unclear phylogenetic relationships within the species complex, RAD sequencing was performed on 65 individuals from five populations. Our integrated analysis of phylogenetic trees, neighbor nets, and genetic structures indicate that the species complex should not be considered as separate species. Moreover, our findings reveal differences in the degree of genetic differentiation among the five populations, ranging from low to moderate, which might be influenced by geographical distance and gene flow. The Fst values also confirmed that genetic differentiation intensifies with increasing geographic distance. Collectively, this study clarifies the complex phylogenetic relationships within the species complex, elucidates the genetic diversity and differentiation across the studied populations, and offers valuable genetic insights that contribute to the broader study of evolutionary relationships and population genetics within the species.
物种鉴定和系统发育关系的厘清是物种界定的基本目标。然而，基于形态学、地理分布和基因组数据来完成这些任务面临着挑战。此前，蕨类植物属的两个物种，即×和，是根据形态特征描述的；它们在系统发育上与相互交织，未能形成单系类群。为了解决物种复合体内部不明确的系统发育关系，对来自五个种群的65个个体进行了RAD测序。我们对系统发育树、邻接网络和遗传结构的综合分析表明，物种复合体不应被视为独立的物种。此外，我们的研究结果揭示了五个种群之间遗传分化程度的差异，从低到中等，这可能受到地理距离和基因流的影响。Fst值也证实了遗传分化随着地理距离的增加而加剧。总体而言，本研究厘清了物种复合体内部复杂的系统发育关系，阐明了所研究种群的遗传多样性和分化情况，并提供了有价值的遗传学见解，有助于更广泛地研究物种内部的进化关系和种群遗传学。
