Bhardwaj Indu, Kumar Vijay, Singh Somvir, Sharma Arti Jamwal, Kumari Shikha, Bhardwaj Nidhi, Dulta Kanika, Peter Lukas, Verma Richa, Kumar Nitesh, Ahlawat Yogesh K, Malik Anurag, Okla Mohammad K, Porcel Rosa, Mulet José M, Jayabalan Karthikeyan
Division of Microbiology, Career Point University, Hamirpur 176041, Himachal Pradesh, India.
Department of MLT, Abhilashi University, Chailchowk, Mandi 175028, Himachal Pradesh, India.
Plants (Basel). 2025 Jul 13;14(14):2154. doi: 10.3390/plants14142154.
Plant growth-promoting rhizobacteria (PGPR) are eco-friendly and sustainable options for agrochemicals, particularly for enhancing crop productivity under stress conditions. The present research aims to isolate and characterize native PGPR from tomato rhizospheric soil and to evaluate their effectiveness as a dose-dependent response to enhance the growth of tomato seedlings. Out of 112 isolates, 10 bacterial strains were selected based on key PGPR traits, including indole-3-acetic acid (IAA), ammonia production, hydrogen cyanide (HCN), exopolysaccharide (EPS) synthesis, hydrolytic enzyme activity, potassium solubilization, antifungal activity against , and tolerance to pH and heat stress. Molecular identification via 16S rRNA gene sequencing confirmed that these isolates belong to the genera and . So-1 and sp. So-12 produced the highest levels of IAA (2.6-24.1 µg/mL). In vitro tomato seed germination tests using bacterial suspensions at three concentrations (10, 10, and 10 CFU/mL) showed dose-dependent improvements, with T1 increasing germination up to 108.3% compared to the control. In polyhouse trials using cocopeat formulations, seedling growth improved noticeably. T2 increased the root length (28.3 ± 2.98 cm) by over 1560%, and the shoot length (35.7 ± 0.57 cm) increased by 55% against the control, whose root length is 1.7 ± 0.47. The chlorophyll amount of the treated leaves further showed significant results over the control. Collectively, these findings suggest that using native PGPR in a dose-dependent way can help tomato seedlings grow better and promote more sustainable crop production.
植物促生根际细菌（PGPR）是农用化学品的环保且可持续的选择，特别是在胁迫条件下提高作物生产力方面。本研究旨在从番茄根际土壤中分离和鉴定本地PGPR，并评估其作为剂量依赖性反应增强番茄幼苗生长的有效性。在112株分离物中，根据关键的PGPR特性选择了10株细菌菌株，包括吲哚-3-乙酸（IAA）、氨产生、氰化氢（HCN）、胞外多糖（EPS）合成、水解酶活性、钾溶解、对……的抗真菌活性以及对pH和热胁迫的耐受性。通过16S rRNA基因测序进行的分子鉴定证实这些分离物属于……属。So-1和……sp. So-12产生的IAA水平最高（2.6 - 24.1 µg/mL）。使用三种浓度（10⁶、10⁷和10⁸ CFU/mL）的细菌悬浮液进行的体外番茄种子发芽试验显示出剂量依赖性的改善，与对照相比，T1使发芽率提高至108.3%。在使用椰糠配方的温室试验中，幼苗生长明显改善。与对照（根长为1.7 ± 0.47 cm）相比，T2使根长（28.3 ± 2.98 cm）增加超过1560%，茎长（35.7 ± 0.57 cm）增加55%。处理叶片的叶绿素含量相对于对照进一步显示出显著结果。总体而言，这些发现表明以剂量依赖性方式使用本地PGPR可以帮助番茄幼苗更好地生长并促进更可持续的作物生产。
