老芒麦种质资源抗寒性综合评价及冷胁迫下的生理反应  

A comprehensive evaluation of cold resistance and the physiological response of Elymus sibiricus genotypes

作　　者：柳文蔚 刘鑫 雷映霞 周青平 刘志峰 王沛 LIU Wen-wei;LIU Xin;LEI Ying-xia;ZHOU Qing-ping;LIU Zhi-feng;WANG Pei(Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station,Institute of Qinghai-Tibetan Plateau,Southwest Minzu University,Chengdu 610041,China;Ningxian Inspection Station for Quality and Safety of Agricultural Products,Qingyang 745200,China)

机构地区：[1]西南民族大学四川若尔盖高寒湿地生态系统国家野外科学观测研究站,西南民族大学青藏高原研究院,四川成都610041 [2]宁县农产品质量安全监测检验站,甘肃庆阳745200

出　　处：《草业学报》2023年第8期152-163,共12页Acta Prataculturae Sinica

基　　金：国家自然科学基金(No.31802122);国家牧草产业技术体系青藏高原牧草育种岗位项目(CAR34);中央高校基本科研业务费(2021PTJS28)资助

摘　　要：为了筛选出抗寒性强的老芒麦种质并深入研究其抗寒机制,本研究采用盆栽法,测定了-4℃冰冻处理下43份老芒麦种质资源的相对电导率、叶绿素含量、最大光化学效率,并通过隶属函数综合评价法从中筛选出一份最抗寒种质(I-1-4-1)和一份低温敏感种质(09-244)。进一步对I-1-4-1与09-244进行4℃冷处理和-4℃冰冻处理,分析了低温胁迫下I-1-4-1与09-244叶片相对含水量、细胞膜透性、渗透调节物质、抗氧化系统、叶绿素荧光特性等指标的差异。结果表明:-4℃胁迫下,I-1-4-1的叶绿素含量、光系统Ⅱ最大光化学效率、实际光化学效率、光化学淬灭系数、非光化学淬灭系数均高于09-244,表明I-1-4-1能维持光合作用高效进行;I-1-4-1叶片中超氧阴离子、过氧化氢含量均低于09-244,而过氧化氢酶的活性高于09-244,表明相比于09-244,I-1-4-1具有更强的活性氧清除能力;I-1-4-1的相对电导率和丙二醛含量均低于09-244,表明I-1-4-1的细胞膜受损程度较低;此外,I-1-4-1通过积累更多的游离脯氨酸含量以提高渗透调节能力来适应低温胁迫引起的细胞脱水。主成分分析共提取了2个主成分,累积贡献率超过85%,其中,第一主成分主要为叶绿素荧光和细胞膜透性变化的相关指标;第二主成分主要为渗透调节物质的变化情况。研究结果为老芒麦抗寒性评价及抗寒种质筛选提供了参考。In this study,we screened for Elymus sibiricus genotypes with strong cold resistance,and investigated the mechanism of cold resistance.In a pot experiment,43 wild-type E.sibiricus germplasm lines were subjected to a freezing treatment at-4℃,and the relative electrical conductivity,chlorophyll content,and maximum photochemical efficiency were determined.The data were subjected to a multivariate membership analysis to evaluate the cold resistance of these diverse lines.On the basis of this analysis,a cold-resistant genotype(I-1-4-1)and a cold-sensitive genotype(09-244)were selected.Chilling(4℃)and freezing treatments(-4℃)were applied to I-1-4-1 and 09-244.The differences in leaf relative water content,cell membrane permeability,osmotic substance content,antioxidant system capacity,and chlorophyll fluorescence parameters between I-1-4-1 and 09-244 under cold stress were analyzed.Under-4℃freezing stress,the chlorophyll content,maximum photochemical efficiency of photosystem II,actual photochemical efficiency,photochemical quenching coefficient,and non-photochemical quenching coefficient were higher in I-1-4-1 than in 09-244,indicating that I-1-4-1 could maintain efficient photosynthesis.Under-4℃freezing stress,the superoxide anion and hydrogen peroxide contents in the leaves were lower in I-1-4-1 than in 09-244,while catalase activity was higher in I-1-4-1 than in 09-244,indicating that I-1-4-1 had a stronger ability to scavenge reactive oxygen species compared with 09-244.The relative electrical conductivity and malondialdehyde content were lower in I-1-4-1 than in 09-244,indicating that the membrane system of I-1-4-1 was less damaged under freezing stress.In addition,I-1-4-1 was better able to adapt to cell dehydration induced by freezing stress by accumulating more free proline to improve osmoregulation.Two principal components were extracted by a principal component analysis.Their cumulative contribution to explaining the variation in cold resistance was>85%.The first principal component was mainly rela

关 键 词：老芒麦 冷害 冻害 叶绿素荧光 活性氧 

分 类 号：S543.9[农业科学—作物学]