分枝期水盐胁迫对紫花苜蓿生长及生理特征的影响  

Combined Effect of Water and Salt Stress on Growth and Physiological Traits of Alfalfa at Branching Stage

作　　者：田德龙[1] 侯晨丽 徐冰[1] 任杰[1] 张琛 TIAN Delong;HOU Chenli;XU Bing;REN Jie;ZHANG Chen(Institute of Water Resources for Pastoral Area,Ministry of Water Resources,Huhhot 010020,China;School of Energy and Environment,Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]水利部牧区水利科学研究所,呼和浩特010020 [2]内蒙古科技大学能源与环境学院,内蒙古包头014010

出　　处：《灌溉排水学报》2023年第4期8-14,共7页Journal of Irrigation and Drainage

基　　金：内蒙古自治区科技计划项目(2019GG022-03)。

摘　　要：【目的】探讨分枝期水盐胁迫对紫花苜蓿生长及生理特征的影响。【方法】以紫花苜蓿为研究对象,于2018—2019年在内蒙古磴口县圣牧高科经济园区内开展盆栽试验,设置3个水分胁迫处理:W1(55%θf~70%θf)、W2(70%θf~85%θf)、W3(85%θf~100%θf),并设置4个盐分胁迫处理:S0(<1.0 g/kg)、S1(1.5 g/kg)、S2(3.0g/kg)、S3(4.5 g/kg),在苜蓿初花期测量各处理的地上部分、根系生物量以及地上部分植株渗透调节物质和抗氧化酶活性,探究水盐胁迫对紫花苜蓿水分消耗、生长及生理特性的影响。【结果】与单一水分和盐分胁迫相比,水盐胁迫导致苜蓿耗水量和地上生物量进一步降低。在低水处理下,添加适宜的盐分(≤3 g/kg)可提高苜蓿自身的脯氨酸量、Na+量以及过氧化物酶(POD)活性,降低超氧化物歧化酶(SOD)活性,缓解干旱对苜蓿的氧化损害,促进苜蓿生长。其中,S2W1处理下的茎叶脯氨酸量、Na+量及POD活性相比S0W1处理提高74.28%、17.28%和34.60%,SOD活性减少9.87%,耗水量、地上部分生物量相比S0W1处理分别增加6.48%和2.17%。【结论】干旱和盐分复合胁迫条件下,紫花苜蓿表现出一定的交叉适应现象,盐分质量分数在2~3 g/kg、灌水量在田间持水率的70%~85%时,最适宜苜蓿生长。【Objective】Alfalfa is sensitive to water stress at branching stage,but how a simultaneous salinity stress affects this sensitivity is not well understood.The objective of this paper is to address this issue.【Method】Pot experiments were conducted in 2018—2019 at the Shengmu High-tech Economic Park,in Dengkou County,Inner Mongolia.It consisted of three water treatments with the soil water content kept at 55%~70%(W1),75%~85%(W2),and 85%~100%(W3)of the field capacity,respectively.Each water treatment had four salinity stresses with the soil salt content set at 1.0(S0),1.5(S1),3.0(S2)and 4.5(S3)g/kg,respectively.In each treatment,we measured osmotic substances,antioxidant enzymatic activities,above-and below-ground biomass at early flowering stage.【Result】Water and salinity stresses reduced water consumption and aboveground biomass more considerably when they worked collectively than working separately.When the water stress was minor,however,imposing a slight salinity stress with soil salt content≤3 g/kg can increase the contents of proline and Na+,boosted peroxidase(POD)activity,and reduced superoxide dismutase(SOD).This alleviated oxidative damage of the water stress,thereby promoting crop growth.Compared with S0+W1,S2+W1 increased the contents of proline and Na+,and boosted POD activity,by 74.28%,17.28%and 34.60%,respectively,while reducing SOD activity by 9.87%.These led to an increase in water consumption and aboveground biomass by 6.48%and 2.17%,respectively.【Conclusion】When water stress is not severe,imposing a slight salinity stress can improve the tolerance of alfalfa to water and salinity stress at branching stage.For all treatments we studied,keeping soil salt content in the range of 2~3 g/kg and soil water content in the range of 70%~85%of the field water capacity was optimal to improve resistance of the crop to both salinity and water stresses.

关 键 词：水盐胁迫 紫花苜蓿 生物量 渗透调节物质 抗氧化酶活性 

分 类 号：S27[农业科学—农业水土工程]