Use of plant-associated beneficial microbes, especially endophytes are getting popular day by day as they occupy a relatively privileged niche inside different plant tissues with lesser competition for food and shelter than rhizosphere. The effects of different physical factors like temperature, rainfall, and seasonal variation and UV radiation on plant growth promoting endophytic communities are less pronounced than those on the rhizospheric and phylloplane microbes. This present work has been compromised with further utilization of an indigenous rice (Oryza sativa L.) root endophytic Azotobacter sp. strain Avi2 (MCC 3432) (AzA) as a bio-formulation for sustainable rice production based on several physiological parameters (plant height, root length/weight, leaf area, yield, chlorophyll contain), in-vitro comparative plant growth promoting assays, greenhouse and field experiments (dry and wet season). Treatments with AzA exhibited higher yield as well as maximal chlorophyll fluorescence (Fm) of flag leaves in flowering and grain filling stages indicating higher photosynthetic rates. Scanning electron microscopic image of rice roots demonstrated accumulation of bacterial biofilm at the junction of primary and lateral root confirming the root-colonizing ability of the bacterium. The results of the study were quite encouraging as AzA exhibited better vegetative and reproductive growth of rice in pot and field experiment compared to formulated rhizospheric Azotobacter sp. (commercial product). Apart from that plants treated with AzA (supplemented 50% nitrogenous fertilizer of recommended dose) exhibited similar yield parameters when it was compared with the recommended dose of fertilizer (RDF; 120:60:60 mg N:P:K kg⁻¹ soil/ without any bacterial). Therefore, it can be concluded that application of this plant growth promoting endophyte can reduce a substantial amount of N-fertilizer for field application.

与植物相关的有益微生物的使用，尤其是内生菌，正日益流行，因为它们在不同植物组织内部占据着相对特权的生态位，与根际相比，它们在食物和栖息地方面的竞争较少。温度，降雨量，季节变化和紫外线辐射等不同物理因素对促进植物生长的内生群落的影响远不及根际和叶平面微生物。目前的工作已受到进一步利用本地稻根（内生稻）内生Azotobacter sp。的折衷。菌株Avi2（MCC 3432）（AzA）作为基于多种生理参数（植物高度，根长/体重，叶面积，产量，叶绿素含量）的可持续水稻生产的生物制剂，体外比较植物生长促进试验，温室和田间试验（干湿）季节）。AzA处理显示出较高的产量以及在开花和籽粒充实阶段旗叶的最大叶绿素荧光（Fm），表明较高的光合速率。水稻根的扫描电子显微镜图像表明，细菌生物膜在初级和侧根交界处积累，证实了细菌的根定殖能力。研究结果令人鼓舞，因为AzA与配方的根际固氮菌相比，在盆栽和田间试验中，水稻表现出更好的营养生长和生殖生长。（商业产品）。除了用AzA（建议剂量补充50％氮肥）处理过的植物与推荐剂量的肥料（RDF; 120：60：60 mg N：P：K kg ^-1土壤/没有任何细菌）。因此，可以得出结论，这种促进植物生长的内生菌的施用可以减少用于田间施用的大量N肥料。