Chhetri Sushmita, Sherpa Mingma Thundu, Sharma Laxuman
Department of Horticulture, School of Life Sciences, Sikkim University, Sikkim, India.
Department of Microbiology, Nar Bahadur Bhandari Government College, Sikkim, India.
Sci Rep. 2025 May 3;15(1):15558. doi: 10.1038/s41598-025-98953-6.
The rhizosphere hosts a diverse group of beneficial bacteria that can serve as an alternative to chemical fertilizers. Exploring the potential traits of these bacteria can lead to sustainable farming practices, promoting crop yields while minimizing environmental impact. The present study was conducted to characterize and identify native plant growth-promoting bacteria (PGPB) from the rhizosphere of tomato plants cultivated in the organic state of Sikkim, India. Seventy bacterial strains were isolated from different tomato cultivation sites in Sikkim and characterized for their plant growth-promoting (PGP) traits. Out of these, eight potential bacterial strains were selected, and identified as Klebsiella variicola AST1, Bacillus cereus AST3, Enterobacter sichuanensis AST4, Enterobacter mori KH2, Bacillus cereus SG1, Enterobacter sichuanensis SG2, Enterobacter asburiae YG1, and Priestia aryabhattai YG2. Among them, Enterobacter sichuanensis AST4 demonstrated notable ammonia production (55.14 ± 0.03 mM), phosphate solubilization (564.6 ± 0.19 µgmL), and nitrogen fixation potential. Similarly, Klebsiella variicola AST1 exhibited the highest indole-3-acetic acid (IAA) production (125.33 ± 0.2 µgmL) during in vitro experiments. Likewise, Enterobacter sichuanensis SG2 displayed substantial gibberellic acid (GA) production (18.3 ± 0.02 µgmL), and siderophore production (85%), against the uninoculated control. Greenhouse experiments further revealed that Klebsiella variicola AST1 significantly improved agronomic performance, with increases in plant height (70%), root length (86%), number of leaves (36.6%), and fresh and dry root weight (77% and 58.3% respectively), compared to the uninoculated control. These findings underscore the potential of rhizospheric bacteria from Sikkim's organic tomato fields to enhance plant growth and agricultural productivity, promoting a sustainable crop production system.
根际存在着各种各样的有益细菌，它们可以替代化学肥料。探索这些细菌的潜在特性有助于实现可持续农业实践，在尽量减少对环境影响的同时提高作物产量。本研究旨在对印度锡金邦有机种植的番茄植株根际的本地植物促生细菌（PGPB）进行特性分析和鉴定。从锡金邦不同的番茄种植地点分离出70株细菌菌株，并对它们的植物促生（PGP）特性进行了表征。其中，挑选出8株潜在的细菌菌株，分别鉴定为Variicola克雷伯菌AST1、蜡样芽孢杆菌AST3、四川肠杆菌AST4、森氏肠杆菌KH2、蜡样芽孢杆菌SG1、四川肠杆菌SG2、阿氏肠杆菌YG1和阿氏Priestia aryabhattai YG2。其中，四川肠杆菌AST4表现出显著的产氨能力（55.14±0.03 mM）、解磷能力（564.6±0.19 µgmL）和固氮潜力。同样，在体外实验中，Variicola克雷伯菌AST1产生吲哚-3-乙酸（IAA）的能力最强（125.33±0.2 µgmL）。同样，与未接种对照相比，四川肠杆菌SG2表现出大量的赤霉素（GA）产生（18.3±0.02 µgmL）和铁载体产生（85%）。温室实验进一步表明，与未接种对照相比，Variicola克雷伯菌AST1显著提高了农艺性能，株高增加了70%，根长增加了86%，叶片数量增加了36.6%，鲜根和干根重量分别增加了77%和58.3%。这些发现强调了锡金邦有机番茄田根际细菌在促进植物生长和提高农业生产力方面的潜力，有助于建立可持续的作物生产系统。
