Extensive pollen immigration and no evidence of disrupted mating patterns or reproduction in a highly fragmented holm oak stand

作     者：Joaquín Ortego Raúl Bonal Alberto Muñoz JoséMiguel Aparicio 

作者机构：Grupo de Investigación de la Biodiversidad Genética y CulturalInstituto de Investigación en Recursos Cinegéticos-IREC(CSICUCLMJCCM)Ronda de Toledo s/nE-13005 Ciudad RealSpain Departamento de Ecología EvolutivaMuseo Nacional de Ciencias Naturales(CSIC)C/JoséGutiérrez Abascal 2E-28006 MadridSpain Departamento de Didáctica de las Ciencias ExperimentalesFacultad de EducaciónUniversidad Complutense de MadridC/Rector Royo Villanova s/nE-28040 MadridSpain Centre de Recerca Ecològica i Aplicacions Forestals(CREAF)Cerdanyola del VallèsE-08193 BarcelonaSpain 

出 版 物：《Journal of Plant Ecology》 (植物生态学报（英文版）)

年 卷 期：2014年第7卷第4期

页      面：384-395页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 07[理学] 0901[农学-作物学] 0902[农学-园艺学] 0713[理学-生态学] 

基　　金：Postdoctoral JAE-Doc(Consejo Superior de Investigaciones Científicas)and Juan de la Cierva(Ministerio de Economía y Competitividad)contracts(to J.O.,R.B.and A.M.).Junta de Comunidades de Castilla-La Mancha and European Social Fund(PII1C09-0256-9052) CONSOLIDER-MICINN(CSD2008-00040) Ministerio de Ciencia e Innovación(CGL2008-00095/BOS). 

主　　题：forest fragmentation genetic diversity paternity analyses pollen dispersal pollen pool structure selfing tree density 

摘      要：Aims Forest fragmentation and reduced tree population densities can poten-tially have negative impacts on mating patterns,offspring genetic diversity and reproductive performance.the aim of the present study is to test these hypotheses comparing an extremely fragmented,low tree density(~0.02 trees/ha)holm oak(Quercus ilex l.)stand from Central spain with a nearby high tree density stand(~50 trees/ha).Methods We genotyped adult trees and seeds from the low-density stand(436 seeds from 15 families)and the high-density stand(404 seeds from 11 families)using nine microsatellite markers.With these data,we performed paternity analyses,determined pollen flow,mating patterns and pollen pool structure,and estimated progeny genetic diversity in both stands.We also studied seed set and production and performed a pollen supplementation experiment to determine whether reduced tree density has limited foreign pollen availability.Important Findings We have found extensive pollen immigration(75%)into the low tree density stand and monte Carlo simulations revealed that pollen moves larger distances than expected from null models of random dispersal.mating patterns and differentiation of pollen pools were similar in the high-density stand and the low-density stand but we found higher inter-annual differentiation of pollen pools in the for-mer.Progeny genetic diversity and self-fertilization rates did not dif-fer between the low-density stand and the high-density stand.seed set rates were significantly lower in the low-density stand than in the high-density stand and experimental cross-pollen supplementation evidenced that foreign pollen availability is indeed a limiting factor in the former.However,seed crops did not differ between the low-density stand and the high-density stand,indicating that limitation of foreign pollen is not likely to be of great concern in terms of reduced seed production and potential recruitment.Poor forest regeneration due to other ecological and human factors is probably a more important threat for the persistence of fragmented and low tree density stands than reduced pollen flow and only extremely small and isolated tree populations would be expected to suffer severe loss of genetic diversity in the long term.