外源褪黑素对铝胁迫下紫花苜蓿生长状况和质膜透性的影响  

Effects of Exogenous Melatonin on Alfalfa Growth and Plasma Membrane Permeability under Aluminum Stress

作　　者：李庆玺 刘莉 尹亚敏 尹俊 李启娇 郑立文 崔东毅 马向丽[1] LI Qingxi;LIU Li;YIN Yamin;YIN Jun;LI Qijiao;ZHENG Liwen;CUI Dongyi;MA Xiangli(Faculty of Animal Science and Technology,Yunnan Agricultural University,Kunming 650201,China;College of Water Conservancy,Yunnan Agricultural University,Kunming 650201,China;Yunnan Grassland Supervision and Management Station,Kunming 650202,China;Diqing Prefecture Institute of Animal Husbandry and Veterinary Science,Diqing 674499,China)

机构地区：[1]云南农业大学动物科学技术学院,云南昆明650201 [2]云南农业大学水利学院,云南昆明650201 [3]云南省草原监督管理站,云南昆明650202 [4]迪庆州畜牧兽医科学研究院,云南迪庆674499

出　　处：《云南农业大学学报（自然科学版）》2023年第6期1059-1066,共8页Journal of Yunnan Agricultural University:Natural Science

基　　金：云南省农业基础研究联合专项(202301BD070001-163);洱源县饲草产业科技特派团(202304BI090008)。

摘　　要：【目的】探讨不同浓度褪黑素对紫花苜蓿(Medicago sativa L.)幼苗铝毒害的缓解作用,以期为应用褪黑素在酸铝土壤上种植紫花苜蓿提供理论依据。【方法】以耐铝性差异显著的紫花苜蓿品种WL525HQ (耐受型)和三得利(敏感型)为材料,采用水培法育苗,在不同浓度褪黑素(0、5、10、20、50和100μmol/L)预处理后进行铝胁迫,测定紫花苜蓿幼苗地上部和地下部生物量、根系伸长率、根尖铝含量以及质膜透性。【结果】铝胁迫下,2份材料的生长都受到严重抑制,其根系伸长率、地上部和地下部干质量显著下降(P<0.05);与单独铝胁迫相比,外源褪黑素预处理下上述3个指标值显著增大(P<0.05),且其随褪黑素浓度的增加呈先升高后降低的变化趋势,并在20μmol/L褪黑素预处理下达到最大值,WL525HQ和三得利的相对根系伸长率分别增加55%和59%,地上部干质量分别增加14%和33%,地下部干质量分别增加47%和54%。铝胁迫下,WL525HQ和三得利的根尖铝含量、相对电导率和MDA含量显著增加(P<0.05);随着褪黑素浓度的增加,上述3个指标呈先下降后上升的变化趋势,并在20μmol/L褪黑素预处理下降到最低,此时WL525HQ和三得利的根尖铝含量较铝单独处理分别降低20%和24%,相对电导率分别降低14%和21%,MDA含量分别降低30%和40%,且WL525HQ的变化趋势较三得利更为明显。【结论】外源褪黑素可有效缓解铝毒对紫花苜蓿造成的损伤,且褪黑素浓度为20μmol/L时缓解效果最好。[Purpose]To explore the alleviating effect of different concentrations of melatonin on aluminum toxicity in alfalfa(Medicago sativa L.)seedlings,providing a theoretical basis for planting alfalfa and the application of melatonin on acid-aluminum soil.[Methods]Two alfalfa varieties named WL525HQ(tolerant type)and Suntory(sensitive type)were used as materials,and the seed-lings were cultivated using hydroponics at different concentrations(0,5,10,20,50,100μmol/L)melatonin pretreatment followed by aluminum stress,and the changes of aboveground and under-ground biomass,root elongation,root tip aluminum content and plasma membrane permeability of al-falfa seedlings were measured.[Results]Under aluminum stress,the growth of both materials was severely inhibited,and the root elongation rate and the dry weight of aboveground and underground of materials decreased significantly(P<0.05);compared with the only aluminum stress treatment,the above-mentioned three indexes of the treatment with melatonin pretreated increased significantly(P<0.05),and showed a trend of first increasing and then decreasing with the increase of melatonin concentration,reaching the maximum at 20μmol/L melatonin treatment,the relative root elongation rate of WL525HQ and Suntory increased by 55%and 59%,respectively;the aboveground dry weight increased by 14%and 33%,respectively;and the underground dry weight increased by 47%and 54%,respectively.Under aluminum stress,the root tip aluminum content,relative conductivity and MDA content of WL525HQ and Suntory increased significantly(P<0.05);with the increase of melatonin concentration,the above-mentioned three indexes decreased first and then increased,reaching the minimum with 20μmol/L melatonin treatment.At this time,compared with the only aluminum stress treatment,the aluminum content in the root tips of WL525HQ and Suntory decreased by 20%and 24%,respectively;the relative conductivity decreased by 14%and 21%,respectively;the MDA con-tent decreased by 30%and 40%,respectively,and the change trend of

关 键 词：铝胁迫 紫花苜蓿 褪黑素 生长发育 质膜透性 

分 类 号：S963.223.3[农业科学—水产养殖]