末次刈割时间对苜蓿根颈抗氧化系统及抗寒性的影响  

The effect of last cutting time on the antioxidant system and cold resistance of alfalfa root-neck

作　　者：陈卫东 张玉霞[1,2] 张庆昕 刘庭玉[1] 王显国[3] 王东儒[4] CHEN Wei-dong;ZHANG Yu-xia;ZHANG Qing-xin;LIU Ting-yu;WANG Xian-guo;WANG Dong-ru(Agricultural College,Inner Mongolia University for Nationalities,Tongliao 028041,China;Inner Mongolia Autonomous Region Forage Crop Engineering Technology Research Center,Tongliao 028000,China;College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China;Seed Industry Development Section,Hohhot Agriculture And Animal Husbandry Technology Promotion Center,Hohhot 010000,China)

机构地区：[1]内蒙古民族大学农学院,内蒙古通辽028041 [2]内蒙古自治区饲用作物工程中心,内蒙古通辽028000 [3]中国农业大学草业科学与技术学院,北京100193 [4]呼和浩特市农牧技术推广中心种业发展科,内蒙古呼和浩特010000

出　　处：《草业学报》2022年第9期129-138,共10页Acta Prataculturae Sinica

基　　金：内蒙古自然科学研究基金项目(2020MS03081);国家牧草产业技术体系(CARS-34);内蒙古自治区科技计划项目(2021GG0109);内蒙古民族大学研究生科研创新资助项目(NMDSS2161)资助。

摘　　要：为探究不同末次刈割时间对科尔沁沙地生境下紫花苜蓿抗寒性的影响及其与低温冷冻胁迫下抗氧化系统变化的关系,以‘公农1号’紫花苜蓿为材料,于翌年秋季进行不同末次刈割时间处理,越冬前期挖取越冬器官并进行-10,-15,-20,-25和-30℃低温冷冻胁迫处理,以低温冷藏(4℃)为对照,测定紫花苜蓿根颈的相对电导率及丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的变化,利用相对电导率根据Logistic回归方程计算半致死温度,并对半致死温度与抗氧化特性进行相关分析。结果表明,未刈割和8月25日、9月5日、9月15日、9月25日、10月5日、10月15日、10月25日、11月5日末次刈割的苜蓿半致死温度分别为-18.03、-17.61、-17.03、-16.59、-15.80、-15.82、-16.83、-16.34、-17.12℃;紫花苜蓿根颈的半致死温度与-10℃低温冷冻胁迫条件下的POD活性呈显著负相关(P<0.05),与-20℃低温冷冻胁迫条件下的CAT活性呈显著负相关(P<0.05),与-15、-20、-25℃低温冷冻胁迫条件下的SOD活性呈显著或极显著负相关,与-15、-20、-25、-30℃低温冷冻胁迫条件下的MDA含量呈显著或极显著正相关。不同末次刈割时间的苜蓿抗寒性强弱为未刈割>8月25日>11月5日>9月5日>10月15日>9月15日>10月25日>10月5日>9月25日;末次刈割时间通过调控苜蓿根颈的SOD、POD、CAT活性,协同作用清除活性氧、过氧化物和过氧化氢,从而降低膜脂过氧化程度,提高抗寒性,因此在科尔沁沙地地区建议9月5日之前或11月5日之后进行末次刈割。This research explored the effect of different last cutting time on the cold resistance of alfalfa(Medicago sativa)cultivar‘Gongnong No.1’in the Horqin sandy land habitat and the relationship between the last cutting time and changes in the antioxidant system under low temperature stress.The experiment included last cutting times of August 25,September 5,September 15,September 25,October 5,October 15,October 25,and November 5.The crowns were excavated in early winter and subjected to low temperature freezing stress treatments of-10,-15,-20,-25,and-30℃,with low temperature storage(4℃)as the control.Measurements after low temperature storage included the relative electrical conductivity,malondialdehyde(MDA)content,and superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activities.The semi-lethal temperature was calculated from the relative conductivity following a logistic regression equation,and the correlations between the semi-lethal temperature and the antioxidant properties were analyzed.It was found that the semi-lethal temperature for alfalfa last mowed on August 25,September 5,September 15,September 25,October 5,October 15,October 25,and November 5 was,respectively,-18.03,-17.61,-17.03,-16.59,-15.80,-15.82,-16.83,-16.34,-17.12℃;The semi-lethal temperature of alfalfa root neck and the POD and CAT activities under-10℃low-temperature freezing stress were significantly negatively correlated(P<0.05);The semi-lethal temperature and SOD activities under-15,-20,and-25℃low temperature stress were significantly or extremely significantly negatively correlated.There was also a significant or very significant positive correlation between semi-lethal temperature and MDA content under low temperature freezing stress of-15,-20,-25,and-30℃.For the different last cutting times,the cold resistance of alfalfa ranked uncut>August 25>November 5>September 5>October 15>September 15>October 25>October 5>September 25.The last cutting time regulates the SOD,POD,and CAT enzyme activities in the root neck of alfa

关 键 词：苜蓿 末次刈割时间 抗寒性 抗氧化特性 

分 类 号：S541.9[农业科学—作物学]