Plant growth–promoting bacteria (PGPB) inhabiting the phyllosphere improve the growth and yield of plants by producing natural growth regulators. The objectives of this study were to identify and characterize the indigenous PGPB of maize phyllosphere and to evaluate their ability to improve growth and nutritional status of maize (Zea mays L.). The bacteria were isolated from phyllosphere of maize in the fields located at different geographical locations and screened for various plant growth–promoting (PGP) traits. The most promising PGPB were identified by 16S rRNA gene sequence analysis. A greenhouse experiment was carried out in a completely randomized design with the foliar application of 15 different bacterial treatments. It was found that members of genera Bacillus, Pseudomonas, Microbacterium, Stenotrophomonas, Enterobacter, Pseudarthrobacter, and Kocuria were the most dominant PGPB in maize phyllosphere. Foliar spray of M. arborescens, B. subtilis + S. maltophilia, S. maltophilia, B. megaterium, and E. hormaechei significantly increased the shoot dry weight by 10.40, 9.53, 8.86, 8.73, and 6.00% compared with the control, respectively. M. arborescens and S. maltophilia isolates with the ability to produce indole-3-acetic acid (IAA) had positive effects on dry weight of the shoot. E. hormaechei showed a marked nitrogenase activity, phosphate solubilization, and IAA production and was the most effective treatment in improving the uptake of most nutrients. The nitrogenase activity and IAA production were generally considered to be the most important PGP traits of the bacteria when applied via foliar spray. Overall, the findings presented in this study indicate that the foliar application of the leaf-colonizing PGPB enhanced the growth and nutritional status of maize.

中文翻译：

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具有促进植物生长特性的优势叶际细菌对玉米（Zea mays L.）生长和营养的作用

栖息在叶际的植物生长促进细菌 (PGPB) 通过产生天然生长调节剂来改善植物的生长和产量。本研究的目的是确定和表征玉米叶际的本地 PGPB，并评估它们改善玉米（Zea mays L.）生长和营养状况的能力。从位于不同地理位置的田地中的玉米叶际中分离细菌，并筛选各种植物生长促进 (PGP) 性状。通过16S rRNA基因序列分析鉴定出最有希望的PGPB。温室试验采用完全随机设计，叶面施用 15 种不同的细菌处理。发现芽孢杆菌属、假单胞菌属、微杆菌属、狭养单胞菌属、肠杆菌属、Pseudarthrobacter 和 Kocuria 是玉米叶际中最主要的 PGPB。与对照相比，M. arborescens、B.subtilis + S. maltophilia、S. maltophilia、B. megaterium 和 E. hormaechei 的叶面喷洒显着增加了 10.40、9.53、8.86、8.73 和 6.00% 的地上部干重，分别。M. arborescens 和 S. maltophilia 分离株具有产生吲哚-3-乙酸 (IAA) 的能力，对枝条的干重有积极影响。E. hormaechei 显示出显着的固氮酶活性、磷酸盐溶解和 IAA 产生，并且是提高大多数营养物质吸收的最有效处理方法。当通过叶面喷雾施用时，固氮酶活性和IAA产量通常被认为是细菌最重要的PGP特性。全面的，