文献类型：期刊文献

英文题名：Secondary pollen presentation: More than to increase pollen transfer precision

作者：Xu, Yuan-Qing[1,2] Luo, Zhong-Lai[1] Wang, Jia[1,2] Pei, Nan-Cai[3] Zhang, Dian-Xiang[1]

第一作者：Xu, Yuan-Qing

通信作者：Luo, ZL[1]

机构：[1]Chinese Acad Sci, Key Lab Plant Resources Conservat & Sustainable U, South China Bot Garden, Guangzhou 510650, Peoples R China;[2]Univ Chinese Acad Sci, Beijing 100049, Peoples R China;[3]Chinese Acad Forestry, Res Inst Trop Forestry, Guangzhou 510520, Peoples R China

年份：0

外文期刊名：JOURNAL OF SYSTEMATICS AND EVOLUTION

收录：;Scopus(收录号：2-s2.0-85105685059);WOS:【SCI-EXPANDED(收录号:WOS:000649339500001)】；

基金：We thank Lina Mei, Mingsong Wu, and Xiangping Wang for field assistance, and Mingsong Wu for help with photography. We thank Zongxin Ren and Oystein Opedal for helpful comments on previous versions of the manuscript. This research was supported by the Science and Technology Basic Work of the Ministry of Science and Technology of China (Grant No. 2013FY111200), the Chinese Academy of Sciences (Grant No. XDA13020504), the National Natural Science Foundation of China (Grant Nos. 31970252, 31370269, 31570594, 31000109), and the Foundation of Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, CAS (Grant No. PCU201903).

语种：英文

外文关键词：functional pollinator group; generalization; minimized herkogamy; pollen theft; pollination reliability; secondary pollen presentation; tubular flower

摘要：Pollination precision and efficiency have been deemed to be important driving forces in floral evolution. Herkogamy reduction is a main mechanism to increase pollination precision. Secondary pollen presentation (SPP), by which pollen is presented on other floral organs especially pistils, has been widely accepted as a special mechanism to increase pollen transfer precision through spatial reduction of the anther-stigma distance, that is, minimized herkogamy. This overlooks a potential driving force, that is expanding the pollination niche through converting pollen thieves and nectar robbers into effective pollinators. We selected two species as study models with typical pistillate SPP, Pavetta hongkongensis Bremek. (Rubiaceae) and Scaevola taccada (Gaertn.) Roxb. (Goodeniaceae). In both species, two distinct pollinator functional groups were recognized. Short-tongued bees and flies fed on pollen on stigmas but also stole pollen from anthers and robbed nectar, whereas long-tongued hawkmoths and butterflies only collected nectar. Emasculation had no influence on long-tongued pollinators, but significantly decreased the visitation frequency of short-tongued visitors and fruit set, compared to intact flowers, demonstrating short-tongued visitors did not effectively pollinate and acted merely as pollen thieves or nectar robbers when SPP was absent. Data from the two plant species clearly indicated pistillate SPP has additional adaptive advantages of converting ineffective visitors into pollinators and consequently widening the pollination niche, which could help plants overcome environmental stochasticity. Our results suggest that multiple selective forces drive the evolution of SPP and the minimization of herkogamy.