Bacillus methylotrophicus has been demonstrated to promote growth of various plants, whereas the promoting effect of B. methylotrophicus on rice growth has been rarely reported. In this study, B. methylotrophicus DD-1, capable of efficiently promoting the growth of rice, was isolated from the root soil of rice plants. The isolate exhibited potassium-solubilizing (1.18 mg/L), Indole-3-acetic acid (IAA) (87.26 mg/L), Gibberellic acid (GA) (25.91 mg/L) and Siderophore production activity (52.32%). As indicated from the result, plant growth parameters (e.g., dry weight, tiller number, root and shoot length) of rice seedlings treated with the isolate DD-1 were more effective than those of the control group in pot and soilless culture experiments. Moreover, the adsorption capacity of rice roots which were soaked in the bacterial suspension of isolate increased with the increase in concentration and absorption time. In sterilized and unsterilized soil, conformation of root colonization activity by bacterial isolate established by its nearer existence to the rice root. Thus, the B. methylotrophicus DD-1 enhances plant growth promotion by multifarious growth promoting and root colonization traits, thereby augmenting potassium level in soil. Henceforth, the potential bacterium could be exploited for the development of biological fertilizer, leading towards sustainable agronomy.

中文翻译：

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促进水稻幼苗生长的植物生长促进根际杆菌（DD-1）的分离与评价

甲基营养芽孢杆菌已被证明可促进各种植物的生长，而甲基营养芽孢杆菌对水稻生长的促进作用鲜有报道。本研究从水稻根系土壤中分离出能够有效促进水稻生长的 B.methylotrophicus DD-1。该分离物表现出钾增溶 (1.18 mg/L)、吲哚-3-乙酸 (IAA) (87.26 mg/L)、赤霉酸 (GA) (25.91 mg/L) 和铁载体生产活性 (52.32%)。结果表明，在盆栽和无土栽培试验中，DD-1分离株处理的水稻幼苗的植物生长参数（如干重、分蘖数、根长和芽长）比对照组更有效。而且，浸泡在分离菌菌悬液中的水稻根系的吸附能力随着浓度和吸收时间的增加而增加。在已消毒和未消毒的土壤中，细菌分离株的根系定植活性构象通过其离水稻根部更近而建立。因此，B.methylotrophicus DD-1 通过多种生长促进和根系定植性状增强植物生长促进，从而增加土壤中的钾含量。今后，可以利用潜在的细菌来开发生物肥料，从而实现可持续的农学。甲基营养菌 DD-1 通过多种促进生长和根系定植性状增强植物生长促进作用，从而增加土壤中的钾含量。今后，可以利用潜在的细菌来开发生物肥料，从而实现可持续的农学。甲基营养菌 DD-1 通过多种促进生长和根系定植性状增强植物生长促进作用，从而增加土壤中的钾含量。今后，可以利用潜在的细菌来开发生物肥料，从而实现可持续的农学。