践踏频率对千根草构件性状及生理代谢的影响  

Effect of traffic stress on component traits and physiological metabolism of Euphorbia thymifolia

作　　者：杨小琴 毛芮 刘金平[1] 曾晓琳[1] YANG Xiaoqin;MAO Rui;LIU Jinping;ZENG Xiaolin(College of Life Science,China West Normal University,Nanchong 637009,Sichuan,China)

机构地区：[1]西华师范大学生命科学院,四川南充637009

出　　处：《草业科学》2021年第12期2372-2380,共9页Pratacultural Science

基　　金：西华师范大学基本科研业务费(17D081);四川省植物资源共享平台(TJPT20160021)。

摘　　要：为开发和利用野生乡土草坪草种质资源千根草(Euphorbia thymifolia),探究其耐践踏性大小及对践踏频率的响应差异,设置轻度(每月3次)、中度(每月5次)、重度(每月10次)3个践踏频率,每次模拟践踏20下,通过测定构件性状、抗氧化酶活性、渗透性物质及光合色素含量,分析践踏对千根草生长和生理的影响。结果显示:1)叶性状对践踏的响应顺序为叶片数>叶长>叶面积>叶宽>叶厚,茎性状对践踏的响应顺序为二级分枝数>最长茎长>总茎长>一级分枝数>节间长,根性状对践踏的响应顺序为主根长>不定根长>主根直径>侧根数>不定根数。2)轻度践踏可促进叶面积和二级分枝数增加,中、重度践踏限制了根、茎、叶的生长与更新。3)践踏显著影响茎和叶中过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)、可溶性蛋白(P)含量(P<0.05),茎对践踏的生理反应及抗性强于叶,茎和叶协同形成耐践踏性的生理基础。4)千根草通过显著增加叶绿素(Chl)含量(P<0.05),降低践踏导致叶片数减少对光合作用的影响,维持Chla/Chlb相对稳定的比值,为千根草生存、生长及抗性提供物质基础。综上,千根草通过构件塑性和生理代谢应对践踏胁迫,重度践踏频次下可存活,宜在汀步草坪建植中推广应用。Euphorbia thymifolia is a wild native turfgrass germplasm resource.To explore its trampling tolerance and response mode to different traffic frequencies,namely mild(3 times per month),moderate(5 times per month),and severe(10 times per month),trampling simulation experiments were performed on potted E.thymifolia for 20 feet each time.After a month of treatment,the parameters including component traits,antioxidant enzyme activity,osmotic substance content,and chlorophyll content were determined to analyze the effects of traffic on the growth and physiology of E.thymifolia.1)The response sequence of leaf traits to traffic was as follows:leaf number>leaf length>leaf area>leaf width>leaf thickness;the response sequence of stem traits to traffic was as follows:secondary branch number>longest length>total length>firstlevel branch number>internode length;and the response sequence of root traits to traffic was as follows:main root length>adventitious root length>main root diameter>lateral root number>adventitious root number.2)Mild traffic increased leaf area and secondary branch number,while moderate and severe traffic limited the growth and regeneration of roots,stems,and leaves.3)Trampling significantly affected the activities of peroxidase(POD),superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA),and soluble protein(SP)content in stems and leaves(P<0.05),but the physiological response and resistance of stems to traffic were stronger than those of leaves.Evaluated together,stems and leaves showed traffic tolerance.4)By significantly increasing chlorophyll(Chl)content(P<0.05),E.thymifolia reduced the influence of leaf number reduction caused by traffic on photosynthesis.Under traffic stress,the ratio of Chla/Chlb was relatively maintained,thus providing support for survival,growth,and resistance.In summary,the morphological and physiological metabolism of E.thymifolia adapted to different traffic frequencies to form traffic resistance,even at severe frequencies,leading to survival and growth.Therefore,E.thymifo

关 键 词：千根草 草坪 生理 叶绿素 构件性状 生长策略 植物资源 

分 类 号：S688.4[农业科学—观赏园艺]