葎草幼苗的生理生化特征对盐胁迫的响应  

Physiological and Biochemical Responses of Humulus scandens Seedlings to NaCl Stress

作　　者：王碧霞[1,2] 黎云祥[2] 丁春邦[1] WANG Bixia;LI Yunxiang;DING Chunbang(College of Life and Basic Sciences, Sichuan Agricultural University, Yaan, Sichuan 625014, China;College of Environmental Science and Engineering, China West Normal University, Nanchong Sichuan 637009,China)

机构地区：[1]四川农业大学生命科学学院,四川雅安625014 [2]西华师范大学环境科学与工程学院,四川南充637009

出　　处：《西北植物学报》2017年第2期321-329,共9页Acta Botanica Boreali-Occidentalia Sinica

基　　金：四川省教育厅项目(12ZB142);西华师范大学科研创新团队资助

摘　　要：采用盆栽法研究葎草(Humulus scandens)幼苗的生物量、气体交换参数、叶水势、叶绿素含量、叶绿素荧光参数、抗氧化酶活性及丙二醛(MDA)含量对不同浓度盐(NaCl)(分别为0、100、200、300、400mmol/L)胁迫的响应,以探讨葎草幼苗对盐胁迫的适应机制及耐性机理。结果表明:(1)随着NaCl胁迫浓度的增加,葎草幼苗生长受到严重抑制,显著降低了根、茎、叶的干重、单叶面积、比叶面积(SLA)和根冠比(R/S)。(2)NaCl胁迫后,葎草幼苗的净光合速率(Pn)、气孔导度(Gs)、胞间CO_2浓度(Ci)、蒸腾速率(Tr)和叶水势(Ψw)均随盐浓度增加呈显著下降趋势,气孔限制值(Ls)和瞬时水分利用效率(WUEi)却显著增加。(3)NaCl胁迫下,叶绿素a(Chl a)和叶绿素b(Chl b)等光合色素含量以及过氧化氢酶(CAT)活性均显著降低,但超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和丙二醛(MDA)含量显著升高,说明植株的抗氧化酶系统对NaCl胁迫具有积极的响应策略。(4)NaCl胁迫显著提高了幼苗最小荧光(F_o)、可变荧光(F_v)、最大荧光(F_m)、表观光合电子传递速率(ETR)和光化学淬灭系数(qP),有效降低了PSⅡ有效光化学量子产量(F_m′/F_o′)、非光化学淬灭系数(q N),并在不同盐浓度梯度下存在着显著的效果差异。研究表明,低浓度(100mmol/L)NaCl胁迫对葎草幼苗生长没有显著影响,但随着浓度的增加,葎草幼苗的气体交换、叶绿素含量、PSⅡ反应能力、抗氧化酶系统均受到抑制,植株的生长发育受到严重影响。The physiological and biochemical characteristics ofHumulus scandensseedlings under NaCl stress(0,100,200,300and400mmol/L NaCl)was studied.The study results indicated that:(1)the growth ofH.scandensseedlings has severely inhibited with the increase of NaCl concentration,and the root,stem and leaf dry weight,single leaf area,specific leaf area(SLA)and root/shoot ratio(R/S)also reduced.(2)The Pn,Gs,Ci,Tr andΨw in leaves ofH.scandensseedlings were all decreased,but the values ofLs andWUEi obviously increased,and the effects strengthened with the increasing of salinity concentration.(3)The NaCl stress obviously had a lower Chl a and Chl b contents CAT activity,and a higher superoxide dismutase(SOD),peroxidase(POD)activities and malondialdehyde(MDA)content.It shows that the antioxidant enzyme system ofH.scandensseedlings has a positive response strategy to NaCl stress.(4)The minimum fluorescence(Fo),variable fluorescence(Fv),maximum fluorescence(Fm),electron transport rate(ETR)and photochemical quenching coefficient(qP)ofH.scandensseedlings were also significantly increased in different NaCl concentrations,but the effective photochemical quantum yield(Fm′/Fo′)and nonphotochemical quenching coefficient of PSⅡ(qN)effectively decreased.In summary,there was no apparent effect ofH.scandensseedlings under low NaCl stress(100mmol/L).However,gas exchange parameters,chlorophyll contents,chlorophyll fluorescence parameters,antioxidant enzyme activities were inhibited with the increase of NaCl concentration.Especially,high concentration of NaCl stress seriously affected the growth ofH.scandensseedlings,their physiological and biochemical indexes showed a gradually decreasing trend.

关 键 词：葎草 盐胁迫 气体交换参数 抗氧化酶活性 叶绿素荧光参数 

分 类 号：Q945.78[生物学—植物学]