Page 95 - 《广西植物》2020年第10期
P. 95

1 4 7 8                               广  西  植  物                                         40 卷
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        LI Jiahui ꎬ HUANG Zhangping ꎬ LU Yongbin ꎬ QIN Xinmei ꎬ HUANG Yusong ꎬ
                                              1                  2∗
                                   LI Huimin ꎬ ZHANG Qiang
      ( 1. Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University)ꎬ Ministry of
       Educationꎬ College of Life Sciencesꎬ Guangxi Normal Universityꎬ Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 2. Guangxi Key Laboratory of Plant
              Conservation and Restoration Ecology in Karst Terrainꎬ Guangxi Institute of Botanyꎬ Guangxi Zhuang Autonomous
                          Region and Chinese Academy of Sciencesꎬ Guilin 541006ꎬ Guangxiꎬ China )

       Abstract: Hemiboea subcapitata is a group of perennial herbs in Gesneriaceaeꎬ which has great morphological variations
       and large distributional rangeꎬ growing on various edaphic substrates in different habitats. In this studyꎬ focusing on
       Hemiboea subcapitataꎬ H. pterocaulisꎬ and two other related variationsꎬ we investigate and describe the diversities of the
       morphology and micromorphologyꎻ outlined the geographic distributions and habitats by consulting specimens and
       literatureꎬ and long ̄term field surveysꎻ in additionꎬ the phylogenetic relationship and haplotype network among all types
       are inferred based on DNA data of the nuclear ITS sequences. The results were as follows: (1) Different variations of the
       Hemiboea subcapitata complex are able to be distinguished through the combination of multiple traits from stemsꎬ leavesꎬ
       flowers and phenology. (2) The leaf cross ̄section anatomical micromorphologies are highly similar in terms of basic
       tissue compositionsꎬ epidermal cell shape and stomatal distributionꎬ while there are differences in presence versus
       absence of the epidermal hairꎬ number of the vascular bundles and arrangementꎬ which are seemingly helpful for the
       classification. (3) Typical H. subcapitata is widely distributed in central and South China and extends to North Vietnamꎬ
       growing on different types of rocksꎬ e.g. limestone and sandstone in the limestone region and/ or Danxia landform etc.ꎬ
       and H. pterocaulis possesses a narrow range in Guilinꎬ Guangxi and is endemic to limestoneꎬ while other two types are
       only distributed in one or a few adjacent limestone hills in Yongfu Countyꎬ Guilin and restricted to limestone substrates
       as well. (4) The haplotype network show that each type of H. subcapitata complex has its own unique and unshared
       haplotypesꎻ the molecular phylogenetic relationships indicate that Hemiboea sp. and H. pterocaulis group togetherꎬ but
       the monophyletic lineage consisting of all indivuduals of the former type (i.e. Hemiboea sp. from Jinzhongshan) is nested
       within the latterꎻ H. subcapitata and H. yongfuensis are reciprocally monophyleticꎬ supporting both of them as
       independent species. In conclusionꎬ at least three indenpendent species are able to be indentified as the H. subcapitata
       complex. The sympatric distribution of all the four variations in South Chinaꎬ and even the coexistence of the three of
       them at the same sites in the same limestone hills do not necessarily mean sympatric speciationꎬ though they likely
       diverged sympatrically via key trait change(s) such as phenological transition of different flowering times that can have
       resulted in reproductive isolation.
       Key words: Hemiboea subcapitata complexꎬ classificationꎬ phylogenyꎬ morphologyꎬ geographical distributionꎬ
       species delimitation


         苦 苣 苔 科 ( Gesneriaceae ) 半 蒴 苣 苔 属          立ꎬ散生紫褐色斑点ꎬ不分枝ꎻ叶对生连基抱茎ꎬ稍
   (Hemiboea C. B. Clarke) ( Clarkeꎬ 1888) 半蒴苣苔      肉质ꎬ全缘或中部以上具浅钝齿ꎬ顶端急尖或渐
   (H. subcapitata C. B. Clarke)植物主要生长在中国            尖ꎬ基部常不相等ꎬ具叶柄ꎬ合生后呈船形ꎬ叶片表

   的华中和华南以及越南北部海拔 100 ~ 2 100 m 的                    面、维管束及叶肉周围散生蠕虫状石细胞ꎻ聚伞花
   山谷、丘陵和山脉中的岩石裂缝、石灰岩、砾岩、花                           序腋生或假顶生ꎻ总苞球形ꎬ顶端具突尖ꎬ无毛ꎬ开
   岗岩或 砂 岩 岩 石 表 面 的 腐 殖 质 中 ( Wang et al.ꎬ          裂后呈船形ꎻ萼片 5ꎬ离生ꎻ花冠筒外疏生腺状短柔
   1998ꎻ韦 毅 刚 等ꎬ 2010 )ꎮ 根 据 « 中 国 植 物 志 »           毛ꎬ内面基部上方有一毛环ꎬ口部上唇 2 浅裂ꎬ下
   (Wang et al.ꎬ1990)和«中国苦苣苔科植物» ( Li &              唇 3 浅裂ꎬ裂片均为半圆形ꎻ花药顶端相连ꎬ退化
   Wangꎬ2005)的记载:半蒴苣苔为多年生草本ꎻ茎直                       雄蕊 3ꎬ中央 1 个ꎬ侧面 2 个ꎬ顶端小头状ꎬ分离ꎻ花
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