Rani Savita, Dhiman Indu, Wati Leela
Department of Microbiology, College of Basic Sciences & Humanities, Chaudhary Charan Singh Haryana Agricultural University, Hisar, 125004, Haryana, India.
Folia Microbiol (Praha). 2025 Apr;70(2):427-439. doi: 10.1007/s12223-024-01195-8. Epub 2024 Sep 5.
Biopriming seeds with beneficial bacteria has potential to enhance seed germination. Therefore, in this investigation, five sulphur-oxidizing bacterial cultures, viz., Pantoea dispersa SOB2, Bacillus velezensis SN06, Bacillus cereus SN20, Bacillus tropicus SN16, and Bacillus megaterium SN11, were evaluated for different plant growth-promoting traits and their impact on Vigna radiata L. (mung bean) and Brassica juncea L. (mustard) seed germination. Among these, three bacterial cultures Pantoea dispersa SOB2, Bacillus velezensis SN06, and Bacillus megaterium SN11 evinced potential for mineral solubilization on solid medium where Pantoea dispersa SOB2 had the maximum solubilization indices-3.06, 5.14, and 2.48 for phosphate, zinc, and potassium respectively. The culture also displayed higher indole acetic acid (113.12 µg/mL), gibberellic acid (162.66 µg/mL), ammonia (5.23 µg/mL), and siderophore (69.53%) production than other bacterial cultures whereas Bacillus cereus SN20 showed maximum exopolysaccharide production (9.26 g/L). Bacterial culture Pantoea dispersa SOB2 significantly ameliorated the germination rate (3.73 no./day) and relative seed germination (208%) of Brassica juncea L., while Bacillus velezensis SN06 and Bacillus cereus SN20 followed with germination rate and relative seed germination of 2.86 no./day and 207%, respectively. Pantoea dispersa SOB2 displayed lowest mean germination time 2.91 days followed by Bacillus megaterium SN11 with 3.19 days. Biopriming with sulphur-oxidizing bacterial cultures, germination parameters of Vigna radiata L. were also markedly improved. Pantoea dispersa SOB2 demonstrated the highest germination rate (6.72 no./day), relative seed germination (115.56%), and minimum mean generation time (1.73 days). Bacillus velezensis SN06 inoculation had a beneficial effect on the seedling growth of Vigna radiata L., whereas Pantoea dispersa SOB2 greatly aided the seedling growth of Brassica juncea L. Results corroborated a prominent positive correlation between seed germination and plant growth-promoting traits. This is the first study on Pantoea dispersa as sulphur oxidizer, displaying plant growth promoting traits and seed germination potential. The potent sulphur-oxidizing bacterial cultures possessing plant growth promoting activities enhanced seed germination under in vitro conditions that could be further explored in field as biofertilizers to enhance the growth and yield of Brassica juncea L. and Vigna radiata L. crop.
用有益细菌对种子进行生物引发有提高种子发芽率的潜力。因此，在本研究中，评估了五种硫氧化细菌培养物，即分散泛菌SOB2、贝莱斯芽孢杆菌SN06、蜡样芽孢杆菌SN20、嗜热芽孢杆菌SN16和巨大芽孢杆菌SN11的不同植物生长促进特性及其对绿豆和芥菜种子萌发的影响。其中，三种细菌培养物，即分散泛菌SOB2、贝莱斯芽孢杆菌SN06和巨大芽孢杆菌SN11在固体培养基上表现出溶解矿物质的潜力，其中分散泛菌SOB2对磷酸盐、锌和钾的溶解指数最高，分别为3.06、5.14和2.48。该培养物还比其他细菌培养物表现出更高的吲哚乙酸（113.12μg/mL）、赤霉素（162.66μg/mL）、氨（5.23μg/mL）和铁载体（69.53%）产量，而蜡样芽孢杆菌SN20表现出最高的胞外多糖产量（9.26g/L）。细菌培养物分散泛菌SOB2显著提高了芥菜的发芽率（3.73粒/天）和相对种子发芽率（208%），而贝莱斯芽孢杆菌SN06和蜡样芽孢杆菌SN20的发芽率和相对种子发芽率分别为2.86粒/天和207%。分散泛菌SOB2的平均发芽时间最短，为2.91天，其次是巨大芽孢杆菌SN11，为3.19天。用硫氧化细菌培养物进行生物引发，绿豆的发芽参数也得到了显著改善。分散泛菌SOB2表现出最高的发芽率（6.72粒/天）、相对种子发芽率（115.56%）和最短的平均世代时间（1.73天）。接种贝莱斯芽孢杆菌SN06对绿豆幼苗生长有有益影响，而分散泛菌SOB2极大地促进了芥菜幼苗生长。结果证实种子发芽与植物生长促进特性之间存在显著正相关。这是第一项关于分散泛菌作为硫氧化剂的研究，该菌表现出植物生长促进特性和种子发芽潜力。具有植物生长促进活性的高效硫氧化细菌培养物在体外条件下提高了种子发芽率，可在田间进一步探索作为生物肥料来提高芥菜和绿豆作物的生长和产量。
