马先蒿属植物花冠分化与繁殖适应的研究进展  

Advances in Floral Divergence and Reproductive Adaptation in Pedicularis L.(Orobanchaceae)

作　　者：郁文彬[1] 蔡杰[1] 王红[1,2] 陈建群[3] 

机构地区：[1]中国科学院昆明植物研究所生物多样性和生物地理学重点实验室 [2]南京大学生命科学学院,南京210093 [3]南京大学生命科学学院

出　　处：《植物学通报》2008年第4期392-400,共9页Chinese Bulletin of Botany

基　　金：国家自然科学基金(No.30570115);中国科学院知识创新工程项目(No.KSCXZ-YW-Z-034)

摘　　要：结合已有的研究报道和作者近年来的工作,对马先蒿属(Pedicularis)植物的花冠多样化成因与繁殖适应特性进行了总结和探讨。通过对该属4种进化花冠型的花器官发生和分化的研究发现,花部各器官在发生和发育初期基本一致,后期上唇形态的分化是导致成熟花形态结构产生较大差异的重要阶段。孢粉学研究认为,花冠类型与花粉萌发孔类型之间具有显著相关性;萌发沟的演化可能与繁殖适应有一定的关系。分子系统学研究表明,多样化的花冠类型在不同的谱系内经过若干次的独立进化而表现出了高度的平行演化(parallelism)。传粉生物学研究证实,该属植物花冠多样化与其主要传粉者熊蜂属(Bombus)昆虫的传粉行为存在较为密切的关系。具有相同(似)花冠类型的马先蒿可能被同种或不同种的熊蜂以相同的方式访问,但在花粉落置位置上存在显著差异,这可能有助于同域分布重叠的物种间在生殖上的机械隔离,而花冠的分化在一定程度上促进了新的物种形成。Floral diversification in Pedicularis （Orobanchaceae） is remarkable among flowering plants. In this paper, we summarize previous studies and discuss recent research into floral diversification and reproductive adaptation in this genus. Developmental studies of Pedicularis reveal that the ontogeny of the four general corolla types is similar in the initiation of floral organs, whereas meristem activity on the upper lip plays an important role in corolla architecture and may have significant contributions to floral differentiation. Palynological studies reveal that floral types are strongly associated with pollen aperture types： 95.2% of long-tubed species were found to be bisyncolpate, as compared with 22.2% in beakless and toothless species. Pollen aperture evolution may be associated with reproductive adaptation at high altitude. Recent molecular phylogenetic analyses indicate that floral characters have a high degree of parallelism, and morphologically similar corollas were apparently derived independently multiple times, perhaps as a result of adaptive radiation. Long corolla tubes were derived from short ones, galea teeth were derived from toothless galeas, and the diverse forms of galea beak were both gained and lost over the course of floral evolution. Field pollination studies demonstrate that corolla type and bumblebee （Bombus Latr.） pollination behavior are highly associated. Species with similar corollas are visited by diverse pollinators with similar foraging patterns, but pollen is apparently deposited in different positions on different pollinators, thus promoting reproductive isolation among sympatric species of Pedicularis. In addition, the differentiation of floral characteristics may have accelerated speciation in Pedicularis.

关 键 词：花冠多样化 花器官发生 平行演化 花粉演化 传粉适应 生殖隔离 

分 类 号：Q945[生物学—植物学]