紫花苜蓿与垂穗披碱草混播比例对其抗寒生长生理特征的影响  

Effects of alfalfa(Medicago sativa)proportion on growth and physiological characteristics of cold resistance in mixtures with Elymus nutans

作　　者：刘彩婷 毛丽萍 阿依谢木[1,2,3] 于应文 沈禹颖[1,2,3] LIU Cai-ting;MAO Li-ping;Ayixiemu;YU Ying-wen;SHEN Yu-ying(College of Pastoral Agriculture Science and Technology,Lanzhou 730020,China;State Key Laboratory of Grassland Agroecosystems,Lanzhou 730020,China;National Demonstration Center for Experimental Grassland Science Education,Lanzhou University,Lanzhou 730020,China)

机构地区：[1]兰州大学草地农业科技学院,甘肃兰州730020 [2]兰州大学草地农业生态系统国家重点实验室,甘肃兰州730020 [3]兰州大学草业科学国家级实验教学示范中心,甘肃兰州730020

出　　处：《草业学报》2022年第7期133-143,共11页Acta Prataculturae Sinica

基　　金：财政部、农业农村部国家牧草产业技术体系(CARS-34);国家基金重点项目(72033009)资助。

摘　　要：为探究混播群落中紫花苜蓿(MS)抗寒生长表型及对低温的响应特征,设置紫花苜蓿与垂穗披碱草4个混播比例(紫花苜蓿占比分别为100%、70%、50%和30%,即MS_(100%)、MS_(70%)、MS_(50%)和MS_(30%))。在温室条件下,播种定苗经25℃育苗45 d后,转入15℃培养10 d,再转入5℃培养10 d,测定分析2个低温阶段混播群落中紫花苜蓿的生长抗寒生理指标。结果表明:从生长特征看,15℃阶段,MS_(70%)紫花苜蓿叶宽长比最小,MS_(50%)紫花苜蓿地上、地下和群落生物量最高,且紫花苜蓿根颈直径最大,分别较MS_(100%)和MS_(70%)高42.8%和46.8%;5℃阶段,紫花苜蓿地上、地下及群落生物量仍以MS_(50%)最高,MS_(50%)和MS_(30%)下紫花苜蓿的株高、分枝数、根颈直径、主根长度等表现较佳。从生理特征看,紫花苜蓿的根系较叶片对低温敏感,15℃阶段,MS_(70%)、MS_(50%)和MS_(30%)紫花苜蓿根系可溶性糖含量较MS_(100%)提高13.1%、25.2%和14.0%,MS_(30%)的根系脯氨酸含量比MS_(100%)高32.9%;5℃阶段,MS_(50%)紫花苜蓿根系可溶性糖含量最高,MS_(50%)和MS_(30%)可溶性蛋白及脯氨酸含量均高于MS_(100%)和MS_(70%)。基于紫花苜蓿生长生理特征综合评价及最优混播比例筛选得知,混播能提升紫花苜蓿生长生理特征对低温的适应,30%~50%的紫花苜蓿混播占比为研究区紫花苜蓿-禾草混播草地建植的适宜比例。A pot experiment was conducted in controlled conditions to assess the growth and physiological characteristics of cold tolerance of alfalfa(Medicago sativa,MS)in mixed planting with Elymus nutans.Four mixture proportions of alfalfa and E.nutans were tested(100%,70%,50% and 30% alfalfa,designated MS_(100%),MS_(70%),MS_(50%) and MS_(30%),respectively).After germination and establishment at 25℃for 45 days,all treatment pots were moved to 15℃ for 10 days,then to 5℃ for another 10 days.The growth and physiological parameters of alfalfa in the four planting ratios with E.nutans under two temperature regimes were analyzed.For the growth characteristics,at 15℃,the leaflet width and length of MS_(70%) was the lowest.The aboveground biomass,alfalfa underground biomass and community biomass of MS_(50%) were the highest.The highest root collar diameter was recorded in MS_(50%),42.8% and 46.8% higher than MS_(100%) and MS_(70%),respectively.At 5℃,the aboveground biomass,alfalfa underground biomass and community biomass was again the highest under MS_(50%),while MS_(50%) and MS_(30%) treatments showed superior performance and cold tolerance for plant height,branch number,root collar diameter and taproot length.For the physiological characteristics,the roots showed more hardiness than leaves.The soluble sugar content in roots of the planting ratios MS_(70%),MS_(50%) and MS_(30%)(13.1%,25.2% and 14.0%,respectively at 15℃)was higher than for MS_(100%)(4.28%).The proline content of alfalfa under MS_(30%)(32.9% at 15℃)was higher than that under MS_(100%)(3.81 mg·g^(-1)).The highest water soluble sugar content in alfalfa roots was measured in MS_(50%),and the soluble protein and proline contents of plants in MS_(50%) and MS_(30%) planting ratios were higher than those under MS_(100%) and MS_(70%) at 5℃.In summary,multivariate evaluation of alfalfa growth physiological characteristics and the screening of the optimal mixed proportion indicated that mixed planting with E.nutans can improve alfalfa growth and physiolog

关 键 词：紫花苜蓿 混播比例 抗逆性 生长特征 生理特征 

分 类 号：S541.9[农业科学—作物学] S543.9