摘要
为探明外源褪黑素(MT)对大豆幼苗耐盐性的调节作用,筛选出不同盐胁迫下适宜的施用浓度.以大豆品种田友-2986 为试验材料,设置3 个盐浓度(低盐S3:3 g/L、中盐S5:5 g/L、高盐S7:7g/L)和6 个MT浓度(M0:0 μmol/L、M1:25 μmol/L、M2:50 μmol/L、M3:75 μmol/L、M4:100 μmol/L、M5:150 μmol/L),分析了大豆幼苗形态参数、生物量、抗氧化酶活性及渗透调节物质含量.随着盐胁迫程度的增大,大豆幼苗的根系形态参数、生物量、根冠比、抗氧化酶活性和渗透调节物质含量降低,丙二醛含量增加.低盐(S3)和中盐(S5)胁迫下,外施50 μmol/L MT大豆根系总长度、侧根数、SOD和POD较不施加分别提高了52.30%,19.98%,74.10%,40.03%(低盐)和68.52%,19.24%,81.72%,37.42%(中盐);高盐(S7)胁迫下,外施75 μmol/L MT分别提高了71.17%,19.11%,80.79%和27.01%.盐胁迫下,外源25～100 μmol/L的MT不同程度上促进了大豆幼苗生长,提高耐盐性.隶属函数综合评价表明,在低、中盐胁迫下,50 μmol/L MT的缓解盐害效果最好;高盐胁迫下,MT这一适宜浓度在75 μmol/L.MT缓解大豆幼苗盐害主要在于它提高抗氧化酶活性和渗透调节物质含量,降低了丙二醛含量,从而缓解了盐胁迫下大豆的氧化胁迫和渗透胁迫.
Abstract
To investigate the effect of exogenous melatonin(MT)on salt tolerance of soybean seedlings,and to screen the appropriate application concentration under different salt stress.The soybean variety Tianyou-2986 was used as the test material,and 3 salt concentrations(low salt S3:3 g/L,medium salt S5:5 g/L,high salt S7:7 g/L)and 6 MT concentrations were set(M0:0 μmol/L,M1:25 μmol/L,M2:50 μmol/L,M3:75 μmol/L,M4:100 μmol/L,M5:150 μmol/L),the morphological parameters,biomass,antioxidant enzyme activity and osmoregulatory substance con-tent of soybean seedlings were analyzed.With the increase of salt stress,the root morphological parameters,biomass,root-shoot ratio,antioxidant enzyme activity and osmoregulatory substance content of soybean seedlings decreased,while the malondialdehyde content increased.Under low salt(S3)and medium salt(S5)stress,The number of total length,lateral roots,SOD and POD of 50 μmol/L MT were increased by 52.30%,19.98%,74.10%,40.03%(low salt)and 68.52%,19.24%,81.72%and 37.42%(medium salt),respectively.Under high stress(S7),75 μmol/L MT increased by 71.17%,19.11%,80.79%and 27.01%,respectively.Under salt stress,exogenous 25-100 μmol/L MT promoted soybean seedling growth and improved salt tolerance to different degrees.The overall evaluation of the affiliation function showed that 50 μmol/L MT was the most effective in alleviating salt damage un-der low and medium salt stress,and the suitable concentration of MT was 75 μmol/L under high salt stress,and the main reason for the alleviation of salt damage in soybean seedlings was that MT increased the activities of antioxi-dant enzymes and osmoregulatory substance content,and reduced the content of malondialdehyde,which could alle-viate oxidative and osmotic stresses of soybeans under salt stress.
基金项目
新疆生产建设兵团重大科技项目(2021AA003)
塔里木大学校长基金(TDZKYS202301)
塔里木大学校级研究生科研创新项目(TDGRI202254)
国家科技期刊平台
NSTL
万方数据