Wang Lin-Lin, Zhang Chan, Yang Ming-Liu, Zhang Guo-Peng, Zhang Zhi-Qiang, Yang Yong-Ping, Duan Yuan-Wen
Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming Yunnan China; Plant Germplasm and Genomics Center the Germplasm Bank of Wild Species Kunming Institute of Botany Chinese Academy of Sciences Kunming Yunnan China; Institute of Tibetan Plateau Research at Kunming Kunming Institute of Botany Chinese Academy of Sciences Kunming Yunnan China.
College of Life Sciences Henan Normal University Xinxiang Henan China.
Ecol Evol. 2016 Dec 20;7(2):541-549. doi: 10.1002/ece3.2636. eCollection 2017 Jan.
Pollination systems and associated floral traits generally differ between core and marginal populations of a species. However, such differences are rarely examined in plants with a mixed wind- and bumblebee-pollination system, and the role of wind pollination during range expansion in ambophilous plants remains unclear. We compared floral traits and the contributions of bumblebee and wind pollination in refugium and marginal populations of the ambophilous plant . We found that most floral traits differed between the two populations, and those traits associated with the shift to wind pollination were pronounced in the marginal population. Bumblebee visitation rates varied significantly, but were generally low in the marginal population. Wind pollination occurred in both populations, and the efficiency was lower than that of bumblebee pollination. Two types of pollen grains, namely round and fusiform pollen, were transported to a stigma by bumblebees and wind, but fusiform pollen contributed to wind pollination to a larger degree, especially in the marginal population. Our results suggest that wind pollination was enhanced by pollen dimorphism in the marginal population of , and wind pollination may provide reproductive assurance when bumblebee activity is unpredictable during range expansion, indicating that ambophily is stable in this species and shift in pollination system could be common when plants colonize new habitats.
一个物种的核心种群和边缘种群的授粉系统及相关花部性状通常存在差异。然而，在具有风媒和熊蜂混合授粉系统的植物中，此类差异很少被研究，而且在兼性授粉植物的范围扩张过程中风媒授粉的作用仍不清楚。我们比较了兼性授粉植物避难所种群和边缘种群的花部性状以及熊蜂授粉和风媒授粉的贡献。我们发现，两个种群的大多数花部性状存在差异，且与向风媒授粉转变相关的性状在边缘种群中更为明显。熊蜂访花率差异显著，但在边缘种群中总体较低。两个种群均存在风媒授粉，且其效率低于熊蜂授粉。熊蜂和风将两种类型的花粉粒，即圆形和梭形花粉，传播到柱头上，但梭形花粉对风媒授粉的贡献更大，尤其是在边缘种群中。我们的结果表明，在该植物的边缘种群中，花粉二型性增强了风媒授粉，并且在范围扩张期间当熊蜂活动不可预测时，风媒授粉可能提供繁殖保障。这表明该物种的兼性授粉是稳定的，并且当植物定殖新栖息地时授粉系统的转变可能很常见。
