干旱胁迫对鹰嘴紫云英种子萌发及幼苗叶绿素荧光特性的影响  

Effects of drought stress on seed germination and chlorophyll fluorescence characteristics of seedling of Astragalus cicer

作　　者：戴海根 吴宏伟 吴尚卫 崔莹[1] 杨冰 第乙林 赵春旭 DAI Hai-gen;WU Hong-wei;WU Shang-wei;CUI Ying;YANG Bing;DI Yi-lin;ZHAO Chun-xu(College of Grassland Science,Gansu Agricultural University,Key Laboratory of Grassland Ecosystem,Ministry of Education,Pratacultural Engineering Laboratory of Gansu Province,Sino-US Centers for Grazingland 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：《草原与草坪》2022年第5期95-105,共11页Grassland and Turf

基　　金：国家自然科学基金项目(31760699)。

摘　　要：为探明鹰嘴紫云英(Astragalus cicer)在干旱胁迫下的种子萌发及幼苗叶绿素荧光特性,本研究采用聚乙二醇(PEG-6000)溶液模拟干旱胁迫,在鹰嘴紫云英种子萌发期共设置7个浓度处理,分别为0(对照)、5%、10%、15%、20%、25%、30%,分析种子萌发及生长特性;幼苗期共设置4个浓度处理,分别为0(对照)、10%(轻度)、20%(中度)、30%(重度),分析不同胁迫时间(0、2、4、6、8、10 d)下的幼苗光合色素含量及荧光参数动态变化特征。结果显示:(1)在5%~10%PEG下,种子萌发和胚根生长得到一定程度促进,发芽势、胚根长度、干重等显著上升,而随胁迫程度加深,种子萌发及生长受到明显抑制,于30%PEG下,发芽率趋近于0,相对胁迫率趋近于100%。(2)轻度胁迫下,光合色素含量小幅度上升,非光化学淬灭系数(NPQ)显著增加,第10天较对照增加110.6%(P<0.05);中度胁迫下,叶绿素b含量、NPQ呈先升高后降低趋势,实际光化学量子Yield含量、相对光合电子传递速率(ETR)于胁迫末期显著降低,第10天较对照分别减少34.2%、50.6%;重度胁迫下,叶绿素含量呈降低趋势,而类胡萝卜素含量于胁迫中期明显增加,第6天较对照增加20.5%,Yield、ETR于胁迫后期明显减小,第10天较对照分别减少42.5%、61.4%。综上所述,鹰嘴紫云英对轻度、中度干旱胁迫具有较强耐受性,能在幼苗期提升叶片内光合色素含量、加快光合电子传递速率、增加光化学电子产量、增强热耗散性能等一系列生理调节措施来适应逆境,而对重度干旱胁迫抵抗力较差,种子萌发及生长受到严重抑制,幼苗光合系统遭到严重破坏,叶绿素含量及荧光参数显著下降。In order to investigate the seed germination and chlorophyll fluorescence characteristics of Astragalus cicer seedlings under drought stress,polyethylene glycol(PEG-6000)solution was used to simulate drought stress.Seven concentration treatments were set up at the germination stage of the seeds of Astragalus cicer,which were 0(control),5%,10%,15%,20%,25%,30%,respectively.The characteristics of seed germination and growth were determined after treatment.The seedings were treated with drought stress induced by 0(CK),10(mild stress),20(moderate stress),30(severe stress)percent solution of PEG for 0,2,4,6,8 and 10 days respectively to determine the dynamic change of photosynthetic pigment content and chlorophyllfluorescence parameters in seedlings.The results showed that under 5%~10%PEG treatment,seed germination and radicle growth were promoted to a certain extent,germination viability,radicle length and dry weight increased significantly.However,the germination and growth of seeds were significantly inhibited with the increasing stress degree.Under 30%PEG treatment,germination rate was close to 0,and relative stress rate was close to 100%.Besides,under mild stress,the photosynthetic pigment content was slightly increased,and the non-photochemical quenching coefficient(NPQ)was significantly increased,which was 110.6%higher than that of the control on day 10(P<0.05).Under moderate stress,chlorophyll b content and NPQ increased first and then decreased.The actual photochemical quantum yield content and relative photosynthetic electron transport rate(ETR)decreased significantly at the end of stress,and decreased by 34.2%and 50.6%compared with the control on day 10,respectively.Under severe stress,chlorophyll content showed a decreasing trend,while carotenoid content increased significantly at the middle stage of stress and increased by 20.5%compared with the control on the 6th day.The Yield and ETR decreased significantly at the late stage of stress and decreased by 42.5%and 61.4%compared with the control on the 10th d

关 键 词：鹰嘴紫云英 干旱胁迫 种子萌发 叶绿素荧光 

分 类 号：S529[农业科学—作物学]