荒漠植物根际促生菌的筛选及其对青贮玉米幼苗的促生效应

Screening of rhizosphere growth-promoting bacteria of desert plants and its promoting effects on silage maize seedlings

选取实验室前期分离所得的植物根际促生菌(PGPR),对其进行形成生物膜能力、产铁载体能力、产IAA能力、产ACC脱氨酶能力以及溶磷和解钾能力测定,选取具有促生特性的菌株进行盆栽试验。共筛选出16株具有促生特性的菌株,其中BW2-6、MC35、BW35、HS1-1和SHM2在活体试验中促生效果较优。菌株BW2-6对青贮玉米幼苗的株高、基茎粗、地上部干质量、根鲜质量、根长、根表面积、根体积、相对含水量、比根长和全株鲜质量促生效果最佳,相比对照分别增加了81.00%、54.70%、156.79%、163.27%、107.35%、131.18%、175.12%、44.96%、74.48%和190.69%;菌株SHM2对地上部鲜质量和根干质量促生效果最佳,相比对照分别增加了237.85%和72.96%;菌株BW35对平均叶面积促生效果最佳,约为对照的2.33倍;对照组根冠比均高于处理组,处理组中菌株BW35根冠比最高,相比对照降低了10.18%,菌株BW2-6根冠比最低,相比对照降低了51.93%,不同菌株之间促生效果差异显著。主成分分析结果表明,5株对青贮玉米幼苗生长促进作用较好的菌中以菌株BW2-6促生效果最佳。

The plant growth-promoting bacteria(PGPR)isolated in the laboratory in the previous stage were selected for the determination of biofilm formation ability,iron carrier production ability,IAA production ability,ACC deaminase production ability,phosphorus solubilization and potassium solubilization ability.The strains with growth promoting characteristics were selected for a pot experiment.A total of 16 strains with growth-promoting characteristics were screened out,among which 5 strains BW2-6,MC35,BW35,HS1-1 and SHM2 had better growth-promoting effects in vivo experiments.Among them,BW2-6 had better growth promoting effects on plant height,basal stem diameter,above-ground dry mass,root fresh mass,root length,root surface area,root volume,relative water content,specific root lenth and whole plant fresh mass with increases of 81.00%,54.70%,156.79%,163.27%,107.35%,131.18%,175.12%,44.96%,74.48%and 190.69%,respectively.Strain SHM2 had the best growth promoting effect on above-ground fresh mass and root dry mass,which increased by 237.85%and 72.96%,respectively,compared with the control group.Strain BW35 had the best growth promoting effect on average leaf area,which was about 2.33 times that of the control.The ratio of root to shoot ratio in the control group was higher than that in the treatment group.The ratio of root to shoot ratio of strain BW35 in the treatment group was the highest,which was reduced by 10.18%compared with the control group.The ratio of strain BW2-6 was the lowest,which was reduced by 51.93%compared with the control group.The results of principal component analysis showed that strain BW2-6 had the best growth promoting effect on silage maize seedlings among the 5 strains.