高寒退化草地狼毒繁殖性状的选择及其适应性  

Selection for reproductive traits and their adaptation in Stellera chamaejasme in degraded alpine grassland

作　　者：骆望龙 夏建强 李佳欣 孙淑范 汪睿 张勃[1] LUO Wang-long;XIA Jian-qiang;LI Jia-xin;SUN Shu-fan;WANG Rui;ZHANG Bo(College of Grassland Science,Gansu Agricultural University,Key Laboratory for Grassland Ecosystem of Ministry of Education,Pratacultural Engineering Laboratory of Gansu Province,Sino-U.S.Centers for Grazing Land Ecosystem Sustainability,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学草业学院,草业生态系统教育部重点实验室,甘肃省草业工程实验室,中-美草地畜牧业可持续发展研究中心,甘肃兰州730070

出　　处：《草业学报》2021年第4期121-129,共9页Acta Prataculturae Sinica

基　　金：国家自然科学基金(31960349);甘肃省草学优势学科开放课题-学科建设专项基金(GAU-XKJS-2018-001)资助。

摘　　要：被子植物的繁殖性状在很大程度上被认为是通过传粉者介导的自然选择而进化。为了探究狼毒花性状的适应性,以天祝高寒退化草地狼毒为研究材料,通过检测其繁殖相关性状的选择差和选择梯度,探讨了该物种花表型的适应性及可能的选择机制。结果表明:单花序小花数和冠筒长具有显著的选择差和选择梯度(P<0.05),即受到正的定向选择作用;同时,两性状也检测到显著的非线性选择梯度(P<0.05),表现出稳定选择趋向。株高(即花序高度)受到负定向选择作用,其选择梯度为-0.102±0.039(P=0.008);其他性状,如花冠口大小和单株丛花序数均未检测到显著的选择作用。总体表明,在该研究种群,狼毒的部分繁殖性状表现出适应性进化趋势,株高相对较矮、花筒较长和花序小花数较多的个体越有利于其适合度实现而受到选择。The reproductive traits of angiosperms are widely believed to have evolved largely through pollinatormediated natural selection.The present study focused on Stellera chamaejasme,a dominant poisonous species in degraded alpine meadow in Tianzhu County of Gansu Province in China.S.chamaejasme was chosen as a model species to explore adaptation of floral traits and possible selective mechanisms by detecting their selection differentials and selection gradients.It was found that flower number per inflorescence and corolla tube length had both significant selection differentials and selection gradients(P<0.05),indicating positive directional selection for both traits.Also,significant nonlinear selection gradients(P<0.05)were detected for these two traits,possibly indicating stable selection occurring for them.Negative directional selection was detected for inflorescence length,with a significant linear selection gradient of-0.102±0.039(P=0.008).No significant selection was detected for the other traits measured,such as corolla entrance size and inflorescence number per plant.In conclusion,the data indicate that some reproductive traits in S.chamaejasme exhibited a trend of adaptive evolution under natural selection,and individuals,which have relatively shorter inflorescence length,longer corolla tubes and more flowers per inflorescence,tend to be selected for due to their advantage in achieving reproductive fitness.

关 键 词：狼毒 繁殖性状 选择梯度 适合度 传粉 

分 类 号：S812.6[农业科学—草业科学]