Departament of Biology, Federal University of Lavras, P.O. Box 3037, Zip Code 37200-000, Lavras, MG, Brazil.
Department of Statistics, Federal University of Lavras, P.O. Box 3037, Zip Code 37200-000, Lavras, MG, Brazil.
Microbiol Res. 2019 Jun-Aug;223-225:120-128. doi: 10.1016/j.micres.2019.04.005. Epub 2019 Apr 20.
Plant growth-promoting bacteria have been highlighted by their potential for application in plant production, allowing the reduction of the use of fertilizers and pesticides, which is due to the ability to stimulate the growth of plants by nitrogen-fixation and production of phytohormones, such as indole-3-acetic acid (IAA). The objective of this study was to verify the potential of plant growth promotion of 25 wild isolates from the Agricultural Microbiology Culture Collection of the Federal University of Lavras (CCMA-UFLA) through the evaluation of the biological nitrogen-fixation capacity and the production of IAA. In addition, the growth of three selected strains inoculated on roots of strawberry seedlings in greenhouse conditions was evaluated. The experiment was conducted in a completely randomized design (CRD), with an 8 × 2 factorial schemes involving eight combinations of bacteria: alone, in pairs and threes, plus the control without inoculation. Two fertilizer levels were used (0% and 50% of nitrogen), totaling 16 treatments with eight replicates each. After 75 days, variables such as root length, root dry weight, aerial part length, aerial part dry weight, leaf number, total dry mass and ultrastructural analysis of the inoculated and uninoculated roots, were evaluated. The results showed that the strawberry crop responded positively to inoculation with the three bacteria combined Azospirillum brasilense (Ab-V5) + Burkholderia cepacia (CCMA 0056) + Enterobacter cloacae (CCMA 1285) compared to the uninoculated controls. More expressive responses in terms of plant growth were observed in relation to the combined inoculation of the three bacterial strains plus fertilizer application with 50% of nitrogen.
植物促生菌因其在植物生产中的应用潜力而受到关注，能够通过固氮和产生植物激素（如吲哚-3-乙酸（IAA））来刺激植物生长，从而减少化肥和农药的使用。本研究的目的是通过评估生物固氮能力和 IAA 生产来验证来自拉夫拉斯联邦大学农业微生物培养物收集中心（CCMA-UFLA）的 25 个野生分离株的植物促生潜力。此外，还评估了在温室条件下接种草莓幼苗根系的三个选定菌株的生长情况。该实验采用完全随机设计（CRD）进行，8×2 因子设计方案涉及 8 种细菌的组合：单独、成对和成组，以及不接种的对照。使用了两种肥料水平（0%和 50%的氮），总共有 16 种处理，每种处理有 8 个重复。75 天后，评估了根长、根干重、地上部分长度、地上部分干重、叶数、总干重和接种与未接种根系的超微结构分析等变量。结果表明，与未接种对照相比，草莓作物对三种细菌联合接种（巴西固氮螺菌（Ab-V5）+洋葱伯克霍尔德菌（CCMA 0056）+阴沟肠杆菌（CCMA 1285））反应积极。在接种三种细菌菌株加上 50%氮的肥料应用方面，观察到植物生长方面更具表现力的反应。
