| 摘要: |
| 异养植物对光合作用的依赖降低,其叶绿体基因组常表现出高度的异质性。为探究半寄生植物(异养植物的特殊类群)叶绿体基因组在近缘种间及种内的变异模式,该研究以马先蒿属(Pedicularis L.)粗野-缘毛分支(Rudes-Craspedotrichae Clade)为对象,对22个物种的39个个体的叶绿体基因组进行比较分析。结果表明:(1)粗野-缘毛分支为单系群,划分为8个亚分支。(2)粗野-缘毛分支物种的叶绿体基因组整体结构较为保守,仅在亚分支3的长舟马先蒿(P. dolichocymba)和显盔马先蒿(P. galeata)中发现反向重复(IR)区扩张。(3)2～7个基因(ccsA、ycf15、accD及部分ndh基因)出现假基因化或丢失。(4)亚分支7的红毛马先蒿(P. rhodotricha)部分ndh基因(ndhA、ndhD、ndhF、ndhG、ndhI)表现出种内变异。(5)粗野-缘毛分支叶绿体基因组中鉴定出9个高变异区域,78个蛋白编码基因均受到纯化选择。该研究解析了马先蒿属粗野-缘毛分支叶绿体基因组特征,揭示种内多居群取样研究对揭示半寄生植物叶绿体基因组演化的重要性,并为马先蒿属整合分类学研究提供了有价值的见解。 |
| 关键词: 半寄生植物, 马先蒿属, 系统发育, 叶绿体基因组, 异质性, 演化 |
| DOI：10.11931/guihaia.gxzw202509003 |
| 分类号:Q949 |
| 文章编号:1000-3142(2026)09-1479-15 |
| Fund project:国家自然科学基金项目(32570243,32371700,32071670)。 |
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| Chloroplast genome variation and evolution in the Rudes-Craspedotrichae Clade of Pedicularis |
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WANG Zexun1,3, LIU Rong1,3, WU You1,3, YU Wenbin2*, WANG Hong1*
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1. Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China;2. Center
for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303,
Yunnan, China;3. University of Chinese Academy of Sciences, Beijing 101408, China
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| Abstract: |
| The reduced dependence on photosynthesis in heterotrophic plants is often accompanied by high heterogeneity in their chloroplast genomes. To investigate the variation patterns of chloroplast genomes in hemiparasites(a specialized group of heterotrophic plants)at both inter- and intraspecific levels, in this study, a comprehensive comparative analysis was performed on 39 chloroplast genomes from 22 species within the Rudes-Craspedotrichae Clade of the genus Pedicularis. The results were as follows:(1)The Rudes-Craspedotrichae Clade was supported as a monophyletic group and was divided into 8 subclades.(2)The overall structure of the chloroplast genomes in this clade was relatively conserved, with inverted repeat(IR)expansion detected only in P. dolichocymba and P. galeata of Subclade 3.(3)Pseudogenization or loss occurred in 2-7 genes, including ccsA, ycf15, accD, and several ndh genes.(4)Intraspecific variation was observed in several ndh genes(ndhA, ndhD, ndhF, ndhG, ndhI)of P. rhodotricha from Subclade 7.(5)Nine highly variable regions were identified in the chloroplast genomes of this clade, and all 78 protein-coding genes were found to be under purifying selection. This study elucidates the characteristics of chloroplast genomes in the Rudes-Craspedotrichae Clade, reveals the importance of multi-population sampling at the intraspecific level for revealing chloroplast genome evolution in hemiparasites, and provides valuable insights for integrative taxonomic research on the genus Pedicularis. |
| Key words: hemiparasites, Pedicularis, phylogeny, chloroplast genome, heterogeneity, evolution |
