青藏高原特有属——固沙草属表型变异及其对环境因子的响应  

Response to Environmental Factors of Phenotypic Variations in Orinus Hitchcock(Poaceae),an Endemic Genus from the Qinghai-Tibet Plateau

作　　者：刘涛 吕婷[1,2] 刘玉萍 梁瑞芳[2,3] 陈志[2,3] 苏旭 LIU Tao;Lü Ting;LIU Yuping;LIANG Ruifang;CHEN Zhi;SU Xu(School of Geography, Qinghai Normal University, Xining 810008, China;2Key Laboratory of Medicinal Animal and Plant Resources of the Qinghai-Tibet Plateau in Qinghai Province, Qinghai Normal University, Xining 810008, China;3School of Life Science, Qinghai Normal University, Xining 810008, China)

机构地区：[1]青海师范大学地理科学学院,西宁810008 [2]青海师范大学青海省青藏高原药用动植物资源重点实验室,西宁810008 [3]青海师范大学生命科学学院,西宁810008

出　　处：《西北植物学报》2020年第7期1219-1229,共11页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金项目(31960052,31260052,41761009);中国科学院“西部之光”人才培养计划项目(2019_1_4);青海省自然科学基金项目(2017-ZJ-904);青海省作物分子育种重点实验室开放课题(2017-ZJ-Y14)。

摘　　要：该研究通过测量固沙草属(Orinus)3个物种(青海固沙草、固沙草和居间固沙草)的40个天然居群145个个体的22个表型性状,依据VIF膨胀系数筛选得到年平均降雨(MAP)等9个气候因子和海拔等因子,并采用冗余分析(db-RDA)考察不同物种、不同居群植物表型多样性与多元地理气候环境的关系,探讨该属植物表型多样性驱动机理。结果显示:(1)基于22个植物表型性状,固沙草属天然居群在组内最小方差(Ward)55时可归为2类,居群间表型性状不存在显著的空间自相关性(P>0.05),植物表型多样性高(Shannon-Wiener index,H:1.045~2.734),17个定量的表型性状变异系数(CV)平均值47.84%,而居群间小穗颜色多样性最低(H:0.170),证明固沙草属植物表型性状具有独特的环境响应模式。(2)巢式方差分析显示,固沙草属植物表型在居群间和居群内均存在丰富的变异(F>10,P<0.01),旗叶、颖片和外稃分别是主成分分析中表型总变异的重要组成部分,表型分化系数居群间变异(71.10%)大于居群内(28.90%),固沙草属植物表型变异来源于居群间。(3)冗余分析结果表明,海拔(ALT)和年平均风速(Wind)是决定青海固沙草(O.kokonoricus)和固沙草(O.thoroldii)居群间表型差异性的主要影响因子;极端气候条件[最冷季平均温度(Bio9)和最干季降雨量(Bio14)]对固沙草居群间表型相似性起促进作用,相反干燥度指数(AI)与水气压(Vapr)对其差异性起促进作用;居间固沙草(O.intermedius)居群间表型差异受年均降雨(MAP)、潜在蒸散(PET)和水气压(Vapr)影响。研究认为,固沙草属植物天然居群之间表型变异反映出明显的地理气候变化趋势,这些表型变异是高山植物环境适应性的重要标志。In this study,we evaluated the phenotypic diversity of 40 natural populations from 3 species(O.kokonoricus,O.thoroldii and O.intermedius)of Orinus using 22 phenotypic traits.According to index of VIF,we filtered altitude(ALT)and 9 climatic factors like mean annual precipitation(MAP),adopted db-RDA analysis(Distance-based redundancy analysis)to explore the relationship between multi-geographical climatic environment and phenotypic diversity of different species of different populations,to investigate the mechanism of plant phenotypic diversity of Orinus.The results showed as follows:(1)based on ward clusting of 22 traits,it generated 2 clusters at ward 55 by squared error of within populations,and the spatial autocorrelation among populations were not significant(P>0.05).Our results showed that its pattern responded to the habitats was unique,the Shannon-Wiener(H)index of 17 qualitative traits ranged from 1.045 to 2.734,the average coefficient of variation was 47.84%,the color of spikelet was the lowest phenotypic diversity among populations(H:0.170).(2)Nested analysis of variance revealed that both within and among populations are abundant variation(F>10,P<0.01),principal component analysis also showed that flag leaf and glumes and lemmas traits were important components of total variation,indicating the variation of phenotypic traits among populations(71.10%)was much greater than that within population by Vst(28.90%).The phenotypic variations derived from intra-populations of Orinus.(3)Furthermore,db-RDA proved that ALT and annual mean wind speed were crucial factors for driving the phenotypic dissimilarity between O.kokonoricus and O.thoroldii populations,and extreme climate promoted phenotypic similarity like mean temperature of driest quarter(Bio9)and precipitation of driest month(Bio14)among populations,inversely aridity index(AI)and vapor pressure(Vapr)promoted effects of phenotypic dissimilarity.Phenotypic variation of O.intermedius populations were limited by MAP,potential evaporation(PET)and Vapr.Phenoty

关 键 词：青藏高原 固沙草属 高山植物 表型多样性 冗余分析 

分 类 号：Q346[生物学—遗传学] Q948.11