抗寒锻炼前土壤水分含量对苜蓿抗寒性的影响  

The Effect of Soil Water Content before Cold Hardening on Cold Resistance of Alfalfa

作　　者：曹倩[1] 王显国[1] 张尚雄 刘博文 金美艳 宁亚明[1] CAO Qian;WANG Xian-guo;ZHANG Shang-xiong;LIU Bo-wen;JIN Mei-yan;NING Ya-ming(College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China)

机构地区：[1]中国农业大学草业科学与技术学院,北京100193

出　　处：《中国草地学报》2021年第3期1-9,共9页Chinese Journal of Grassland

基　　金：国家公益性行业科技专项(201403048-2)资助。

摘　　要：设置不同水分处理,即田间持水量(FC)为80%~90%、50%~60%、20%~30%,探究抗寒锻炼前水分对苜蓿(‘公农1号’紫花苜蓿)抗寒性的影响及其生理机制。主要结果如下:与对照组相比,28d干旱处理后苜蓿的叶片变黄、植株变矮,并且随胁迫程度的增加,根相对含水量、净光合速率、气孔导度、最大光化学效率及根水势呈下降趋势,而根系可溶性糖、淀粉、脯氨酸含量及相对电导率呈上升趋势。复水后,经过中度胁迫和重度胁迫的苜蓿植株得到一定程度的恢复。在抗寒锻炼后,经过中度胁迫的苜蓿植株相比其他两组能够保持较高的叶绿素含量、净光合速率、气孔导度、根水势、可溶性糖、脯氨酸含量,较高的低温存活率,及较低的淀粉含量;而经过重度胁迫的苜蓿植株比对照的表现较差。综上,抗寒锻炼前进行适度节水灌溉将有利于苜蓿越冬。Different water treatments(80%~90%,50%~60%,20%~30%of field capacity)were set in the present study to explore the effect of soil water content before cold hardening on cold resistance of alfalfa(Gongnong No.1)and its physiological mechanisms.The results showed that compared with the control(CK)group,the leaves of alfalfa turned yellow and the plants became shorter after 28d of drought stress.With the increase of stress,the relative water content of roots,net photosynthetic rate(Pn),stomatal conductance(Gs),maximum quantum efficiency of photosystemⅡ(Fv/Fm)and root water potential were decreased,while the contents of soluble sugar,starch,proline and relative conductivity were increased.After rehydration,alfalfa under moderate drought(MD)and severe drought(SD)conditions were restored to a certain extent.Compared with the other two groups,alfalfa under MD condition maintained higher chlorophyll content,Pn,Gs,root water potential,soluble sugar and proline contents,higher low temperature survival rate,and lower starch content after cold hardening.However,the performance of alfalfa under SD condition was worse than that of the control group.In conclusion,the moderate water-saving irrigation before cold hardening will be conducive to alfalfa overwintering.

关 键 词：紫花苜蓿 土壤水分 根系 抗寒生理 

分 类 号：S541.1[农业科学—作物学]