Page 59 - 《广西植物》2026年第9期
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9 期             田昌芬等: 基于叶绿体基因组的蔷薇科水榆属系统发育分析及分类处理                                          1 4 9 5

                         ( 1. College of Life Sciencesꎬ Nanjing Forestry Universityꎬ Nanjing 210037ꎬ Chinaꎻ 2. Chengdu Institute of
                                       Biologyꎬ Chinese Academy of Sciencesꎬ Chengdu 610041ꎬ China )

                 Abstract: The genus Micromeles Decne. belongs to Rosaceaeꎬ and is characterized by simple leaves and without
                 persistent sepals when fruiting. Micromeles is widely distributed in Asiaꎬ with approximately 33 species recognized
                 globally and 28 species occurring in China. To clarify the classification status of Micromelesꎬ this study sequenced 18
                 chloroplast genomes of Micromeles using high ̄throughput sequencing and integrated these new data with publicly
                 available sequences from National Center for Biotechnology Information ( NCBI)ꎬ yielding a final dataset of 135
                 chloroplast genomes representing 134 species. Based on this datasetꎬ a chloroplast genome phylogenetic tree of
                 Micromeles was constructed using the methods of maximum likelihood and Bayesian inference. The results were as
                 follows: (1) Micromeles in traditional sense (simple leavesꎬ fruits without persistent sepals) was non ̄monophyleticꎬ but
                 clustered into a clade with the Asian ̄distributed species of Aria (Pers.) Host (simple leavesꎬ fruits with persistent
                 sepals) and formed a sister group with Sorbus s.s. (pinnate leaves). (2) The European ̄distributed species of Ariaꎬ
                 Chamaemespilus Medik. and Torminalis Medik. were clustered together and more closely related to Eriolobus (DC.)
                 M. Roem. (3) Phylogenetic study results supported incorporating the Asian ̄distributed species of the genus Aria into the
                 genus Micromelesꎬ whereas the European ̄distributed species featuring persistent sepals should be retained within Aria.
                 (4) Based on the phylogenetic results and literatureꎬ the expanded Micromeles was supported as a distinct monophyletic
                 genusꎬ and its species range was delimited as comprising 59 speciesꎬ including 4 new combinations (Micromeles chengii
                 (C. J. Qi) Meng Li & C. F. Tianꎬ comb. nov.ꎬ M. eleonorae (Aldasoro) Meng Li & C. F. Tianꎬ comb. nov.ꎬ M. kohimensis
                 (Watt ex C. B. Clarke) Meng Li & C. F. Tianꎬ comb. nov.ꎬ M. verticillata (Merr.) Meng Li & C. F. Tianꎬ comb. nov.). This
                 study provides important evidence for the systematics and evolution of the Maleae in Rosaceae.
                 Key words: Rosaceaeꎬ Micromelesꎬ chloroplast genomeꎬ phylogenyꎬ taxonomic treatment




                水 榆 属 ( Micromeles Decne.ꎬ 单 叶ꎬ 果 期 萼 片        域内学者的广泛支持(Lindleyꎬ 1821ꎻ de Candolleꎬ
            脱落) 属于蔷薇科( Rosaceae) 花楸属( Sorbus L.)               1825ꎻ Decaisneꎬ 1874ꎻ Hookerꎬ 1879)ꎮ 随着研究
            复合群ꎬ其近缘属包括狭义花楸属( Sorbus s.s.ꎬ复                     的深入ꎬ分类学家提出 Sorbus 仅包含复叶类群ꎬ将
            叶) 、 棠 楸 属 ( Cormus Spachꎬ 复 叶 ) 、 白 花 楸 属         单叶类群分为 3 个独立的属( Aria、Chamaemespilus
            [ Aria ( Pers.) Hostꎬ单叶ꎬ果期萼片宿存] 、红花                和 Torminaria) ( Roemerꎬ 1847)ꎮ Decaisne( 1874)
            楸属( Chamaemespilus Medik.ꎬ单 叶) 和 驱 疝 木 属           同样认可 Sorbus 只含复叶类群ꎬ认为 Sorbus 和 Aria
            ( Torminalis Medik.ꎬ单叶) ( 单叶类群各属形态特                各为独立的属ꎬ并将被归入梨属和花楸属的落萼
            征见图 1) ꎮ 该属全世界记录有 33 种ꎬ广泛分布                        类花楸物种分离ꎬ创建了 Micromeles Decne. ( 水榆
            于亚洲地区ꎬ我国是水榆属植物分布中心ꎬ记录                              属)ꎬ随后水榆属的独立性得到了部分分类学家的
            28 种 ( Phipps et al.ꎬ 1990ꎻ Lu & Spongbergꎬ        认可(Koehneꎬ 1890ꎻ Schneiderꎬ 1906ꎻ Kovanda &
            2003ꎻ Aldasoro et al.ꎬ 2004ꎻ Zika & Bailleulꎬ      Challiceꎬ 1981)ꎮ
            2015ꎻ Sennikov & Kurttoꎬ 2017) ꎮ 水榆属最初由                在后续的分类研究中ꎬ水榆属的分类地位依
            Decaisne( 1874) 发 表ꎬ此 前ꎬ其 属 下 物 种 长 期 被            然存在较大争议ꎮ 俞德浚等将水榆属物种分为落
            置于花楸属( Sorbus L.) ꎬ其分类地位也随着花楸                      萼组 [sect. Micromeles (Decne.) Rehd.]ꎬ又将白花
            属的分类处理而变动ꎻ由于分类地位的争议ꎬ花                              楸属物种分为冠萼组( sect. Aria Pers.)ꎬ并归入广
            楸属也有广义花楸属( Sorbus s.l.ꎬ包含单叶、复叶                     义花楸属ꎻPhipps 同样采用广义花楸属的概念ꎬ将
            的所有花楸类物种) 和狭义花楸属( 仅包含复叶                            2 个类群物种以亚属 [subg. Aria (Pers.) G. Beck、
            类群) 之分ꎮ                                            subg. Micromeles ( Decne.) Phipps & al.] 的形式归
                 Lindley 曾将广义花楸属物种以组的形式归入                      入 其 中 ( Gabrielianꎬ 1972ꎻ 俞 德 浚 等ꎬ 1974ꎻ
            梨属(Pyrus L.)ꎬ该处理方式在一段时期内得到领                        Phipps et al.ꎬ 1990ꎻ Lu & Spongbergꎬ 2003)ꎮ 由于
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