海拔及环境因子影响杜鹃属植物的表型特征和化学性状_姚仁秀.pdf

2023,31(2):22259,pages 115doi:10.17520/biods.2022259收稿日期:2022-05-11;接受日期:2022-09-22基金项目:国家自然科学基金(31901208)、国家自然科学基金委员会贵州省人民政府喀斯特科学研究中心项目(U1812401)和贵州省科学技术基金(2019/1237)*通讯作者 Author for correspondence.E-mail:https:/www.biodiversity-海拔及环境因子影响杜鹃属植物的表型特征和化学性状姚仁秀1,2,陈燕1,2,吕晓琴2,3,王江湖2,3,杨付军1,王晓月1,3*1.贵州师范大学生命科学学院,贵阳 550025;2.贵州师范大学贵州省植物生理与发育调控重点实验室,贵阳 550025;3.贵州师范大学西南喀斯特山地生物多样性保护国家林业和草原局重点实验室,贵阳 550025摘要:植物-环境间的长期相互作用驱动着植物表型及次生代谢物的变异。随着海拔梯度的变化,环境中的非生物因子会发生变化,但它们如何影响植物的表型以及次生代谢物的组成和含量,以及植物不同组织器官的次生代谢物是否存在差异,目前有关这方面的研究还较少。本文选取3个不同海拔中的柳条杜鹃(Rhododendron virgatum)和大白杜鹃(R.decorum)(大理苍山居群)及红棕杜鹃(R.rubiginosum)(老君山居群)为研究对象,测定不同海拔的环境因子(温度、相对湿度和相对光照强度),测量和分析了不同海拔植物的表型性状,花蜜体积、糖浓度及花蜜中糖成分(HPLC分析方法),以及植株的茎、叶、花瓣、花粉、花蜜中次生代谢物组成及含量(UPLC-Qtof分析法)。结果表明:随着海拔升高,温度、相对湿度和相对光照强度降低,杜鹃的植株高度、花冠大小和花药体积显著减小,而枝条直径、雌蕊和雄蕊长度显著增大。3种杜鹃在海拔C的花蜜体积和糖浓度均显著高于海拔A和海拔B,海拔C中花蜜的蔗糖成分也显著增多。杜鹃属植物主要含黄酮类、甾体类、苯丙素类、萜类和生物碱类等次生代谢物,随着海拔的变化,这5类次生代谢物质的相对含量没有显著变异,但是它们两两之间存在显著的相关性。杜鹃属植物不同组织中次生代谢物的含量有明显差异,整体来说,花粉和花蜜中次生代谢物的种类和含量要显著低于其他组织。主成分分析结果显示,海拔A和海拔B中杜鹃的表型和化学特征比较相似,海拔C杜鹃的黄酮类物质组成和含量与海拔A和海拔B具有显著差异。本研究表明,随着海拔及其环境因子的变化,杜鹃属植物的表型特征和化学性状都存在一定程度的适应性变异,但表型特征的变异程度远大于次生代谢物的组成和相对含量。相对于植物内在的次生代谢物,环境因子的差异更容易影响植物的表型特征。关键词:杜鹃属;海拔;环境因子;表型特征的变异;次生代谢物的成分和含量姚仁秀,陈燕,吕晓琴,王江湖,杨付军,王晓月(2023)海拔及环境因子影响杜鹃属植物的表型特征和化学性状.生物多样性,31,22259.doi:10.17520/biods.2022259.Yao RX,Chen Y,L XQ,Wang JH,Yang FJ,Wang XY(2023)Altitude-related environmental factors shape the phenotypic characteristics and chemicalprofile of Rhododendron.Biodiversity Science,31,22259.doi:10.17520/biods.2022259.Altitude-related environmental factors shape the phenotypic characteristics andchemical profile of RhododendronRenxiu Yao1,2,Yan Chen1,2,Xiaoqin L2,3,Jianghu Wang2,3,Fujun Yang1,Xiaoyue Wang1,3*1 College of Life Sciences,Guizhou Normal University,Guiyang 5500252 Key Laboratory of Plant Physiology and Development of Guizhou Province,Guizhou Normal University,Guiyang 5500253 Key Laboratory of Southwest Karst Mountain Biodiversity Conservation of National Forestry and Grassland Administration,Guizhou Normal University,Guiyang 550025ABSTRACTAims:Interactions between plants and the environment drive the diversity of plant phenotypes and secondary研究报告姚仁秀等:海拔及环境因子影响杜鹃属植物的表型特征和化学性状2023年|31卷|2期|22259|第2页metabolites.Abiotic factors in the environment are known to vary with altitude,but it remains unclear how thisvariation affects plant characters and secondary metabolite composition,including whether secondary metabolites differamong different tissues and organs within a plant.Methods:We took samples of Rhododendron virgatum,R.decorum,and R.rubiginosum from three different altitudes.We measured environmental factors at each altitude,including temperature,relative humidity,and relative lightintensity.We also measured vegetative traits,characteristics of plants reproductive organs,and nectar features(nectarvolume,sugar concentration,nectar components).We used UPLC-Qtof methods to analyze the levels and compositionof secondary metabolites in the stems,leaves,petals,pollen,and nectar of populations from different altitudes.Results:As altitude increased,the temperature,relative humidity,and relative light intensity decreased.The heights,corolla sizes,and anther volumes of the sampled plants decreased significantly,while the branch diameters and pistiland stamen lengths increased significantly.The floral nectar volume and sugar concentration at the highest altitude(altitude C)were significantly higher than at altitudes A and B,the lowest and middle altitudes.The nectar sucrosecontent in Rhododendron was also significantly higher at altitude C than at the lower altitudes.The secondarymetabolites of the Rhododendron samples did not differ significantly at different altitudesat every altitude,the plantswere dominant in flavonoids,steroids,terpenoids,phenylpropanoids,and alkaloids,and there were significantcorrelations among these components.However,the secondary metabolites did vary between different organs of theplants:nectar and pollen had significantly lower levels of metabolites than branches,leaves,and petals.Additionally,PCA results showed that Rhododendron plants at altitudes A and B were relatively similar in character and metabolites.It also revealed that the flavonoid components of plants at altitude C were different from those at altitudes Aand B.Conclusion:Our results reveal a degree of adaptive variation in phenotypic characteristics and metabolitecomposition of Rhododendron plants at different altitudes.However,phenotypic traits vary much more than thecomposition and relative contents of secondary metabolites.We conclude that environmental factors present atdifferent altitudes are much more likely to shape the external characteristics of plants than to change their internalmetabolic profile.Key words:Rhododendron;altitude;environment factors;phenotypic variation;composition and content of secondarymetabolites植物由于固着生长,其生长繁育过程受到诸多生物和非生物因素的影响(Kergunteuil et al,2018)。传粉者给予的选择压力和植物表型的演化变异密切相关(龚燕兵和黄双全,2007;Souto-Vilars et al,2018)。除传粉者外,环境因子的