Affiliation:
1. Graduate School of Environmental and Life Science, Okayama University, Kita-ku, Okayama, Japan
2. Center for Biodiversity, Forestry and Forest Products Research Institute, Tsukuba, Japan
Abstract
Abstract
Background and Aims
Interspecific difference in pollinators (pollinator isolation) is important for reproductive isolation in flowering plants. Species-specific pollination by fungus gnats has been discovered in several plant taxa, suggesting that they can contribute to reproductive isolation. Nevertheless, their contribution has not been studied in detail, partly because they are too small for field observations during flower visitation. To quantify their flower visitation, we used the genus Arisaema (Araceae) because the pitcher-like spathe of Arisaema can trap all floral visitors.
Methods
We evaluated floral visitor assemblage in an altitudinal gradient including five Arisaema species. We also examined interspecific differences in altitudinal distribution (geographic isolation) and flowering phenology (phenological isolation). To exclude the effect of interspecific differences in altitudinal distribution on floral visitor assemblage, we established ten experimental plots including the five Arisaema species in high- and low-altitude areas and collected floral visitors. We also collected floral visitors in three additional sites. Finally, we estimated the strength and contribution of these three reproductive barriers using a unified formula for reproductive isolation.
Key Results
Each Arisaema species selectively attracted different fungus gnats in the altitudinal gradient, experimental plots and additional sites. Altitudinal distribution and flowering phenology differed among the five Arisaema species, whereas the strength of geographic and phenological isolations were distinctly weaker than those in pollinator isolation. Nevertheless, the absolute contribution of pollinator isolation to total reproductive isolation was weaker than geographic and phenological isolations, because pollinator isolation functions after the two early-acting barriers in plant life history.
Conclusions
Our results suggest that selective pollination by fungus gnats potentially contributes to reproductive isolation. Since geographic and phenological isolations can be disrupted by habitat disturbance and interannual climate change, the strong and stable pollinator isolation might compensate for the weakened early-acting barriers as an alternative reproductive isolation among the five Arisaema species.
Publisher
Oxford University Press (OUP)
Reference89 articles.
1. Experiments on the morphology of Arisaema triphyllum;Atkinson;Botanical Gazette,1898
2. The origins of reproductive isolation in plants;Baack;New Phytologist,2015
3. Some observations on the genus Arisaema on the Nilgiri hills, south India;Barnes;Journal of the Bombay Natural History Society,1935
4. Flowering period, thermogenesis, and pattern of visiting insects in Arisaema triphyllum (Araceae) in Quebec;Barriault;Botany,2009
5. Pollination ecology and reproductive success in jack-in-the-pulpit (Arisaema triphyllum) in Québec (Canada);Barriault;Plant Biology,2010
Cited by
13 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献