Unravelling host-mediated effects on hemiparasitic Mexican mistletoe Psittacanthus calyculatus(DC.)G.Don traits linked to mutualisms with pollinators and seed dispersers  

作　　者：Sandra Rodríguez-Mendieta Carlos Lara Juan Francisco Ornelas 

机构地区：[1]Centro de Investigación en Ciencias Biológicas,Universidad Autónoma de Tlaxcala,km 10.5 Carretera San Martín Texmelucan-Toluca,San Felipe Ixtacuixtla,Tlaxcala 90120,Mexico [2]Departamento de Biología Evolutiva,Instituto de Ecología,A.C.(INECOL),Carretera antigua a Coatepec 351,Xalapa,Veracruz 91080,Mexico

出　　处：《Journal of Plant Ecology》2018年第6期827-842,共16页植物生态学报（英文版）

基　　金：This research was supported by research funds from INECOL(20030/10563);a competitive grant(155686)from the Consejo Nacional de Ciencia y Tecnología(CONACyT)awarded to J.F.O.

摘　　要：Aims While the influence of mistletoe-host interactions on each other’s evolution is well-recognized,the role of interactions between mis-tletoes and its mutualistic pollinators and seed dispersers mediated by host species is relatively unexplored.Methods Here,we examine the effects of host species(Mexican hawthorn Crataegus mexicana DC,black cherry Prunus serotina Ehrh.,leather-leaf Mexican oak Quercus crassipes Bonpl.)on flower morphology,nectar production,pollinator visitation rate and female reproduct-ive fitness in hemiparasitic Mexican mistletoe Psittacanthus caly-culatus(DC.)G.Don(Loranthaceae)populations at three different locations.We first measured the lengths of corolla,style,stamen,exerted stamen and anther,the length and width of the ovary and nectar availability for mistletoe flowers in natural populations.Then,we evaluated flower visitation and measured(length and width)and weighed the fruits and its seeds of mistletoes growing on each of the three host species.Finally,we evaluated the effects of host species,location and flower traits on fruit or seed size variation(both as proxies of reproductive fitness).Important Findings We found mistletoes growing on natural hosts P.serotina and Q.crassipes produced larger flowers,fruits and seeds than mistle-toes on cultivated C.mexicana.However,these differences varied across space.The amount of available nectar and hummingbird vis-itation rates in flowers of mistletoes on C.mexicana was higher at the three sites than in flowers of mistletoes on P.serotina or Q.cras-sipes.The effects of host species,study site and floral trait covariates affected significantly all fitness measures,indicating that mistletoes’reproductive fitness is affected differently depending on the host species and their site of occurrence.These host-associated differ-ences in reproduction might have implications for interactions with mutualistic vectors.

关 键 词：floral and fruit traits hosts HUMMINGBIRDS local host adaptation MISTLETOES NECTAR parasitic plants pollination Psittacanthus 

分 类 号：Q94[生物学—植物学]