Pollination Syndromes of Chinese Gesneriaceae: a Comparative Study between Hainan Island and Neighboring Regions
Pollination Syndromes of Chinese Gesneriaceae: a Comparative Study between Hainan Island and Neighboring Regions
复制标题
DOI：
10.1007/s12229-017-9181-6
复制
发表时间：
2017-03
期刊：
影响因子：
--
通讯作者：
Shao Ling;Q. Meng;L. Tang;M. Ren
中科院分区：
文献类型：
--
作者：
Shao Ling;Q. Meng;L. Tang;M. Ren
苦苣苔科植物种类丰富，是亚洲典型的热带科，具有单系辐射，在中国西南和海南岛具有高度的特有性。中国种具有丰富的花性状和传粉系统，但其多样性的详细格局以及海南岛与中国大陆之间可能存在的差异尚不清楚。本文列举了海南岛及其附近的云南、广西、贵州和广东等省苦苣苔科特有植物的物种多样性和比例。然后，我们研究了物种进化史和主要花性状，以评估岛屿和大陆植物区系的物种形成和授粉综合征。海南有24种（8种特有种），云南有236种（106种特有种），广西有211种（120种特有种），贵州有97种（28种特有种），广东有60种（20种特有种）。海南岛虽然比邻近地区少，可能是面积小的原因，但其特有率很高，仅略低于广西。基于核ITS 1/2和叶绿体trnl - f的系统进化树分析表明，海南特有物种与东南亚物种的遗传关系较近，而与中国大陆物种的遗传关系较近。在生长形态、花冠类型和颜色等大部分花性状上，海南岛种与其他地区没有差异。海南岛和云南省具有4或2雄蕊的物种比例相等，而其他地区的大多数物种具有2雄蕊。海南岛的放射线型物种比例（21%）远高于其他地区（< 10%）。海南岛的大部分种有外露的雄蕊，而其他地区的大部分种有雄蕊。我们没有发现促进岛屿植物区系自交的花性状有增加的趋势。以放光形花冠等特征为支撑的通才传粉机制，似乎为传粉者匮乏的海南岛提供了充分的生殖保障。
The species-rich Gesneriaceae are typically a tropical family in Asia, showing a monophyletic radiation and high endemism in Southwest China and Hainan Island. The Chinese species have diverse floral traits and pollination systems, but the detailed patterns of diversity and possible differentiations between Hainan Island and the Chinese mainland remain unclear. Here, we enumerate the species diversity and proportion of endemics of Gesneriaceae for Hainan Island and the nearby Chinese provinces of Yunnan, Guangxi, Guizhou, and Guangdong. We then investigate the species evolutionary histories and main floral traits to evaluate speciation and pollination syndromes for the island and mainland flora. We recognize 24 (eight endemic) species on Hainan Island, 236 (106 endemic) in Yunnan, 211 (120 endemic) in Guangxi, 97 (28 endemic) in Guizhou, and 60 (20 endemic) in Guangdong. Although Hainan Island harbors fewer species than nearby regions, probably due to its smaller area, its endemic ratio is high, only slightly lower than Guangxi. A phylogenetic tree based on nuclear ITS 1/2 and chloroplastTrnL-F indicated most Hainan-endemic species were genetically close to species from Southeast Asia, rather than mainland China. For most floral traits, e.g., growth form, corolla type and color, Hainan Island species show no differences from other regions. Hainan Island and Yunnan Province have equal proportions of species with four or two stamens, whereas most species in other regions have two stamens. Hainan Island has a much higher percentage (21%) of actinomorphic species than other regions (< 10%). Most species in Hainan Island have exserted stamens, while stamens are included in most species in other regions. We did not find any increased tendency in floral traits that promote selfing for the island flora. Generalist pollination mechanisms, supported by characters such as actinomorphic corolla, appear to provide sufficient reproductive assurance in pollinator-depauperate Hainan Island.