摘要: |
凤仙花属具雌雄异熟和形态多样的花结构,其传粉生物学在物种分化形成及适应性演化方面发挥着关键作用。中国是凤仙花属物种多样性分布中心之一,存在着大量的特有和同域分布现象,但传粉生物学研究资料较少。为揭示同域分布近缘种的传粉综合征分化以及传粉昆虫资源分配问题,该文以同域分布的中国特有种黄麻叶凤仙花(Impatiens?corchorifolia)和多角凤仙花(I.?polyceras)为研究对象,通过野外调查和实验完成了两种凤仙花的传粉生物学研究,比较分析了这两个种的开花物候、花形态结构、传粉昆虫的种类及访花行为和人工授粉实验等方面的异同,结果表明:(1)两种凤仙花的花距特征不同,花距的长度与花蜜量呈正比,但与花蜜含糖量无关。花距类型决定了两种植物的传粉昆虫种类的分化。具短花距的黄麻叶凤仙花的花蜜含量为(4.57 ± 1.43)μL,花蜜糖含量为(45.48 ± 2.28)%,由蜜蜂和胡蜂为其传粉。拥有长花距的多角凤仙花的花蜜含量为(10.15 ± 3.28)μL,花蜜糖含量为(46.12 ± 1.48)%,除蜜蜂和胡蜂传粉外,拥有长喙的天蛾和熊蜂也为其传粉昆虫。(2)两种植物虽然共享3种传粉者,但表现为明显的错峰访花,传粉行为和花通道的差异决定了传粉者携带花粉的部位不一致。(3)繁育系统实验表明,两种植物均表现出明显的杂交障碍和异花授粉偏好性。因此,花距形态差异显著导致传粉综合征分化明显和传粉昆虫行为各异;两种植物授粉均需要传粉昆虫,且均无法自花授粉,呈现异交优势;并且可以通过部分传粉昆虫、花形态差异以及杂交不亲和等情况维持生殖隔离。该研究结果为理解凤仙花属的传粉综合征、同域分布近缘物种传粉昆虫资源分配等方面提供了新资料。 |
关键词: 黄麻叶凤仙花 多角凤仙花 传粉生物学 同域分布 繁育系统 传粉综合征 |
DOI:10.11931/guihaia.gxzw202209008 |
分类号: |
基金项目:国家自然科学基金项目),国家中医药管理局全国中药资源普查项目 |
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Pollination biology of two Chinese endemic and sympatric Impatiens ( Balsaminaceae ) species |
ZHANG Yingduo1, 2, ZHU Yong1, LI Qingqing2, 3, WANG Yuecheng1, TAO Lei1, 2, LI Lu1*
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Abstract: |
The genus Impatiens exhibits a diversity in floral morphology with dichogamous flora features. Its pollination biology plays a key role in species differentiation formation and adaptive evolution. China is one of the centers of species diversity in the genus Impatiens, harboring a large number of endemic and sympatric distributions, but pollination biology is poorly studied. In order to reveal the differentiation of pollination syndromes and the allocation of pollinating insect resources of the sympatric and closely related species, this paper takes Impatiens corchorifolia and I. polyceras, which are endemic to China, as the objects of research, and completes the study of their pollination biology through field investigation and experiments. We compared and analyzed the similarities and differences in flowering phenology, flower morphology, pollinating insect species and their flower-visiting behavior, as well as artificial pollination experiments of the two plants. The results were as follows: (1) Spur characteristics of both plants are different, and the length of the spur was proportional to the amount of nectar, but not to the sugar content of the nectar. Spur morphology essentially determined nectar accessibility. Impatiens?corchorifolia with short floral spacing had a nectar content of (4.57 ± 1.43) μL and nectar sugar content of (45.48 ± 2.28) %, and were pollinated by Apis cerana and Vespa. I.?polyceras with long spur floral spacing had a nectar content of (10.15 ± 3.28) μL and sugar nectar of (46.12 ± 1.48) %, in addition to Apis cerana and Vespa, the long-beaked Macroglossum and Bombus were also pollinated. (2) Although both Impatiens?species partially shared the three bee species, they showed obvious staggered flower visits, and the differences in pollination behavior and differential flower channel dictated that pollinators carried pollen at inconsistent sites. (3) Breeding system experiments showed that both plants showed obvious hybridization barriers and obvious cross-pollination preferences. Thus, significant differences in spur morphology lead to distinct pollination syndrome differentiation and different pollinator behavior; both plants required pollinating insects for pollination, and both were unable to self-pollinate, showing heterogeneous pollination; and reproductive isolation could be maintained by partial pollinators, differences in floral morphology, and heterozygous discordance. The results provided new information for understanding the pollination syndrome of the genus Impatiens and the distribution of pollinator resources of symmetric species. |
Key words: Impatiens corchorifolia Impatiens polyceras Pollination biology Sympatric distribution Breeding system Pollination syndromes |