盐碱土壤促生菌株的筛选及其对玉米发芽的影响

Screening of plant growth-promoting strains from saline-alkali soil and evaluation of their effects on maize germination

摘要:

背景 土壤盐碱化严重制约作物的生长与产量，寻找安全有效的措施降低土壤盐分、实现盐碱化土壤改良尤为迫切。目的 在盐碱土壤中筛选的促生菌株可根据其功能制备微生物改良剂，改善土壤环境、促进植物生长和提高其抗逆性。方法 在盐碱土壤中筛选8株促生菌，验证其解磷、溶钾、耐盐功能，观察其促进玉米种子发芽和玉米幼苗生长的能力。结果 菌株STF1、STF4、STE6、STG1、STF3、STF7为芽孢杆菌属(Bacillus)；菌株STF2为普里斯特氏菌属(Priestia)；菌株STE10为贪铜菌属(Cupriavidus)。8株菌均具有解磷、溶钾、耐盐和促生能力，能够有效促进玉米种子的萌发。其中，芽孢杆菌STF3、STG1耐盐能力最强；解磷、溶钾能力最强的菌株均为普里斯特氏菌STF2。使用菌液可以促进玉米种子发芽，菌株STF3的促进效果最显著；施加微生物菌剂有助于玉米幼苗总鲜重增加，有效促进其生长发育，其幼苗根系的根表面积和根平均直径较CK显著增长，菌株STF2促生效果最显著，并且对土壤养分有促进作用。结论 本研究所筛选菌株均具有促生功能，可根据其功能制备微生物菌剂促进植物生长。

Abstract:

Background Soil salinization severely restricts the growth and yield of crops. It is particularly urgent to develop safe and effective measures to reduce soil salinity and improve saline-alkali soil.Objective Plant growth-promoting bacterial strains screened from saline-alkali soil can be used to prepare microbial ameliorants according to their functions, which can improve the soil environment, promote plant growth, and enhance plant stress resistance.Methods Eight strains of plant growth-promoting bacteria were screened from saline-alkali soil. They were evaluated regarding the phosphorus-solubilizing ability, potassium-solubilizing ability, salt tolerance, and effects on the germination of maize seeds and the growth of maize seedlings.Results Strains STF1, STF4, STE6, STG1, STF3, and STF7 belonged to the genus Bacillus; strain STF2 belonged to the genus Priestia; and strain STE10 belonged to the genus Cupriavidus. All the eight strains had phosphorus-solubilizing, potassium-solubilizing, and plant growth-promoting abilities and salt tolerance, and they promoted the germination of maize seeds. Among them, Bacillus STF3 and STG1 had the strongest salt tolerance, and Priestia STF2 had the strongest phosphorus-solubilizing and potassium-solubilizing abilities. The application of bacterial liquids of these strains promoted the germination of maize seeds, and strain STF3 showcased the most significant plant growth-promoting effect. Moreover, the application of microbial agents increased the total fresh weight of maize seedlings, effectively promoting their growth and development. The root surface area and average root diameter of the seedlings treated with strain STF2 significantly increased compared with those of the control. Furthermore, the microbial agents improved the content of nutrients in the soil.Conclusion All the strains screened in this study have plant growth-promoting functions, and microbial agents can be prepared based on their functions to promote plant growth.