Mast fruiting in a hawkmoth- pollinated orchid Habenaria glaucifolia: an 8-year survey  

作　　者：Ying-Ze Xiong Chang-Qiu Liu Shuang-Quan Huang 

机构地区：[1]School of Life Sciences,Central China Normal University,152 Luoyu Avenue,Hongshan District,Wuhan 430079,China [2]Key Laboratory for Plant Diversity and Biogeography of East Asia,Kunming Institute of Botany,Chinese Academy of Sciences,132 Lanhei Road,Kunming 650204,China

出　　处：《Journal of Plant Ecology》2015年第2期136-141,共6页植物生态学报（英文版）

基　　金：National Science Foundation of China(U1402267 and 31270281)to S.-Q.H.

摘　　要：Aims The hypothesis of predator satiation has been proposed to explain mast fruiting in various flowering plants.it considers that the simultaneous production of large numbers of seeds by a plant population reduces the risk of seed predation for each individual.orchids produce huge numbers of seeds per fruit and rarely experience seed predation.it remains unclear which factors may affect fluctuating fruit production in orchids,which generally suffer a widespread pol-len limitation.To explore the temporal pattern of fruiting and poten-tial factors related to fluctuation in fruit production,we investigated reproductive success of a long-spurred orchid(Habenaria glaucifo-lia)in an alpine meadow with thousands of individuals over 8 years.Methods To estimate reproductive success,pollinator observation was con-ducted by day and at night,and pollinia removal and receipt were recorded in the field population for 8 years.To examine whether fruit set and seed set are pollen limited,we conducted supple-mentary pollination experiments and compared fruit set,seed set and pollinia movement of open-pollinated flowers from 2011 to 2013.We measured lengths of spurs and pollinator probos-cises,and nectar volume and concentration,to identify potential pollinators.Important Findings Hawkmoths were seen to be effective pollinators for H.glauci-folia in 3 years,whereas in the remaining 5 years no pollinators were observed,and consequently pollinia were rarely transferred.Numerous pollinia movements were observed in 2012,2013 and 2014(pollinia removal:48,59 and 85%;pollinia receipt 51,70 and 80%),and correspondingly fruit set was significantly higher in 2012 and 2013(59 and 46%)than in 2011(25%).it was fruit set,rather than seed set,that was pollen limited in this orchid in the 3 years,in that supplementary pollination increased fruit set but did not increase seed set per fruit compared to natural.Three species of hawkmoths had proboscis lengths that matched the spur length of H.glaucifolia.Fruit set in this long spurred orchid depends

关 键 词：Habenaria glaucifolia mast fruiting orchidaceae pollinator scarcity pollen limitation pollinia movement ‘sit and wait’strategy 

分 类 号：Q94[生物学—植物学]