腐植酸悬浮剂对NaCl胁迫下小麦种子萌发和幼苗生长的影响

Effects of Humic Acid Suspension Agent on Seed Germinationand Seedling Growth of Wheat under NaCl Stress

不同分子量的腐植酸具有不同的功能特性。本试验研究不同分子量腐植酸对NaCl胁迫下小麦幼苗生长的影响,以促进腐植酸资源合理开发利用。采用双层滤纸培养法,设置5个处理,分别为清水(T1)、200 mmol/LNaCl溶液(T2)、T2+腐植酸悬浮剂Ⅰ(大分子量,T3)、T2+腐植酸悬浮剂Ⅱ(中等分子量,T4)、T2+腐植酸悬浮剂Ⅲ(小分子量,T5)。结果表明,与T2处理相比,添加腐植酸均可显著降低小麦根部相对电导率,提高小麦发芽率、根长、株高、可溶性糖含量、总叶绿素含量以及过氧化物酶、超氧化物歧化酶、过氧化氢酶活性。上述指标在T3处理下分别提高17.81%、68.46%、90.63%、21.37%、19.88%、61.07%、14.59%、30.70%,T4处理下分别提高了20.12%、101.80%、80.21%、33.42%、23.39%、62.19%、39.43%、46.73%,T5处理则分别提高了21.26%、166.67%、54.17%、35.73%、24.56%、63.43%、43.60%、48.22%。综合分析表明,不同分子量腐植酸均可提高小麦的萌发率以及幼苗的抗盐能力。其中,大分子量腐植酸促进小麦叶片生长效果显著,小分子量腐植酸在促进小麦根系生长、提高植物体内抗氧化酶活性以及增强细胞膜稳定性等方面发挥了重要的作用。

Humic acid with different molecular weights have different functional characteristics.This experiment aimed to investigate the effects of different molecular weight humic acids on the growth of wheat seedlings under NaCl stress,which was beneficial to promoting the rational development and utilization of humic acid resources.The double-layer filter paper culture method was used in the experiment,and five treatments were set as follows:clear water(T1),200 mmol/L NaCl solution(T2),T2+humic acid suspension I(adding high molecular weight,T3),T2+humic acid suspension II(adding medium molecular weight,T4),T2+humic acid suspension III(addingsmall molecular weight,T5).The results showed compared with T2 treatment,the addition of humic acid couldsignificantly reduce the relative conductivity of wheat roots,and increase the germination percentage,root length,plant height,soluble sugar content,total chlorophyll content,and the activities of peroxidase,superoxidedismutase,and catalase of wheat.The above indicators increased by 17.81%,68.46%,90.63%,21.37%,19.88%,61.07%,14.59%,30.70%,respectively in T3 treatment;in T4 treatment,increased by 20.12%,101.80%,80.21%,33.42%,23.39%,62.19%,39.43%and 46.73%,respectively;In T5 treatment,increased by 21.26%,166.67%,54.17%,35.73%,24.56%,63.43%,43.60%,48.22%,respectively.Comprehensive analysis showed that different molecular weights of humic acid could improved the germination percentage and the salt resistance of seedlings.Among them,high molecular weight humic acid had a significant effect on promoting the growth of wheat leaves,while small molecular weight humic acid had played an important role in promoting the growth of wheat roots,improving the activity of antioxidant enzymes in plants and enhancing the stability of cell membranes.