Floral nectary, nectar production dynamics, and floral reproductive isolation among closely related species of Pedicularis

作     者：Ya-Nan Liu Yan Li Fu-Sheng Yang Xiao-Quan Wang 

作者机构：State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China Institute of Alpine Economic Plant Yunnan Academy of Agricultural Sciences Lijiang 674100 China University of Chinese Academy of Sciences Beijing 100039 China 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2016年第58卷第2期

页      面：178-187页

核心收录：

学科分类：07[理学] 0713[理学-生态学] 

基　　金：supported by the National Natural Science Foundation of China(31330008 and 31160047) the Key Research Program of the Chinese Academy of Sciences (KJZD-EW-L07) Science and Technology Basic Work (2013FY112100) 

主　　题：Pedicularis nectary nectar pollination reproductive isolation speciation section Cyathophora 

摘      要：Floral nectar is thought to be one of the most important rewards that attract pollinators in Pedicularis; however, few studies have examined variation of nectary structure and/or nectar secretion in the genus, particularly among closely related species. Here we investigated nectary morphology, nectar quality, and nectar production dynamics in flowers of Pedicularis section Cyathophora. We found a conical floral nectary at the base of the ovary in species of the rex-thamnophila clade. Stomata were found on the sudace of the nectary, and copious starch grains were detected in the nectary tissues. In contrast, a semi-annular nectary was found in flowers of the species of the superba clade. Only a few starch grains were observed in tissues of the semi-annular nectary, and the nectar sugar concentration in these flowers was much lower than that in the flowers of the rexthamnophila clade. Our results indicate that the floral nectary has experienced considerable morphological, structural, and functional differentiation among closely related species of Pedicularis. This could have affected nectar production, leading to a shift of the pollination mode. Our results also imply that variation of the nectary morphology and nectar production may have played an important role in the speciation of sect. Cyathophora.