College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.
Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, Guangzhou 510642, China.
Genes (Basel). 2024 Feb 28;15(3):320. doi: 10.3390/genes15030320.
is a deciduous or semi-deciduous tree species and belongs to the genus of the Meliaceae family. Owing to low natural regeneration and over-exploitation, the species is listed as an endangered species at level II in China and its conservation has received increasing concern. Here, we sampled 447 individuals from 29 populations across the range-wide distribution of the complex in China and assessed their genetic variation using two chloroplast DNA markers. The results showed that the overall haplotype diversity and nucleotide diversity per site were high at = 0.9767 and π = 0.0303 for the A-H fragment and h= 0.8999 and π = 0.0189 for the L-L fragment. Phylogenetic analysis supported the division of the natural distribution of complex into western and eastern regions. The genetic diversity was higher in the western region than in the eastern region, showing significant phylogeographic structure. Genetic differentiation among populations was moderate (Φst=42.87%), and the effects of isolation by distance (IBD) were significant. A neutrality test and mismatch distribution analysis indicated that the distribution of the complex generally did not expand, although a few local populations could likely expand after bottleneck effects. The overall results were complementary to and consolidated previous studies using mitochondrial and nuclear DNA markers. We finally discussed strategies for the genetic conservation of the complex.
是一种落叶或半落叶树种，属于楝科植物属。由于自然更新率低和过度开发，该物种在中国被列为二级濒危物种，其保护越来越受到关注。在这里，我们从中国分布范围内的 29 个种群中采集了 447 个个体，并用两个叶绿体 DNA 标记评估了它们的遗传变异。结果表明，A-H 片段的总体单倍型多样性和每个位点的核苷酸多样性为 = 0.9767 和 π = 0.0303，L-L 片段的 h = 0.8999 和 π = 0.0189。系统发育分析支持将 的自然分布划分为西部和东部两个区域。西部的遗传多样性高于东部，表现出显著的谱系地理结构。种群间的遗传分化中等（Φst = 42.87%），隔离距离（IBD）效应显著。中性检验和不匹配分布分析表明， 的分布总体上没有扩张，尽管一些局部种群在瓶颈效应后可能会扩张。总体结果与使用线粒体和核 DNA 标记的先前研究相辅相成，并最终讨论了 的遗传保护策略。
