Bacillus subtilis Bs10 as an efficient inoculant for growth promotion in soybean plants

Abstract

Currently, food with low levels of pesticides, sustainable agricultural practices and increased crop productivity have gained prominence worldwide. Rhizobacterial inoculants are an alternative to manage large crops that favors sustainable plant growth. Thereby, this study aimed to assess the effect of increasing doses of inoculant based on the rhizobacterium Bacillus subtilis Bs10 compared to the commercial product based on B. subtilis on the development of soybean culture. Two experiments were carried out with two soybean cultivars, M8210 IPRO and M8615 IPRO, assessed at the vegetative and reproductive stages. Doses of B. subtilis Bs10 with 0, 100, 200, 300, 400 mL per 50 kg seeds were inoculated in each experiment, as well as an additional treatment with commercial product based on B. subtilis. Biomass, nodulation, plant height, internodes, number of pods and number of grains of soybean cultivars were assessed. The inoculation of B. subtilis Bs10 significantly (p < 0.05) improved the agronomic characteristics of both soybean cultivars with an increase in shoot and root biomass, nodulation, phosphorus content, and accumulation of nitrogen in the aerial part. The doses of B. subtilis Bs10 between 200 and 350 mL had significant prominence in increasing the variables studied herein.

Efficient dose of Bacillus subtilis UFMT-Pant001 as a plant growth promoter in soybean under greenhouse conditions

“…Chagas Junior et al (2022b) studied seven B. subtilis isolates and also demonstrated the efficiency of B. subtilis as a plant growth-promoting inoculant in soybean plants, , providing initial evidence for its phosphate solubilization and IAA synthesis ability in vitro and its promotion of biomass production in soybean plants grown in a greenhouse; the use of these B. subtilis isolates did not affect soybean nodulation but contributed to increases in the nodule number and weight, consistent with the present experiment. Araújo et al (2012) reported that the simple inoculation of B. subtilis (PRBS-1) provided the greatest increase in cowpea cultivar BRS Guariba growth and greater N fixation and did not affect nodulation at 40 and 55 days after sowing.…”

“…The increases observed may be related to the ability of rhizobacteria to produce plant growth regulators, which are organic substances that influence the physiological processes of plants at low concentrations (Saxena et al, 2019), as previously reported for rhizobacteria of the genus Bacillus that are capable of producing auxins (Kalam et al, 2020;Chagas Junior et al, 2022b). Cerqueira et al (2015) performed in vitro tests and confirmed the production of indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase by four isolates of Bacillus spp.…”

“…The greenhouse experiment results revealed greater increases in biomass (SDM, RDM, and TDM), nodulation (NN, NDM, and NE), nutrients in the shoots (N content and SNA), internode number, and root length in the different soybean cultivars. These increases may be linked to the various mechanisms by which this bacterium acts, such as the production of phytohormones (Kalam et al, 2020;Chagas Junior et al, 2022b) and enzymes (Saxena et al, 2019), increasing nutrient availability through solubilization (Braga Junior et al, 2017;Saeid et al, 2018;Chagas Junior et al, 2022b), the production of volatile compounds (Tahir et al, 2017), and the biological control of plant pathogens (Mardanova et al, 2017;Villarreal-Delgado et al, 2018), among others.…”

“…Several authors have shown that different isolates of B. subtilis can increase shoot and root biomass and yield in soybean, such as Jain, Kumari, Vaishnav, Choudhary, and Sharma (2016), who found that Bacillus isolates increased shoot and root fresh weight and increased the number of lateral roots; Chagas Junior et al (2022a), who showed that inoculation with B. subtilis Bs10 significantly improved the agronomic traits of soybean cultivars with increases in shoot and root biomass, nodulation, phosphorus content, and nitrogen accumulation in the shoots; and Chagas Junior et al (2022b), who demonstrated that inoculation with B. subtilis did not affect soybean nodulation but contributed to an increase in nodule number and weight.…”

Inoculant Bacillus subtilis UFMT-Pant001 promote plant growth and increase of soybean production

“…Plant growth can be directly improved by microbiota, with the production of metabolic compounds with phytohormonal activities at micromolar and nanomolar concentrations. B. subtilis is considered a plant growth-promoting rhizobacteria because it has the ability to synthesize plant hormones such as auxins, gibberellins and cytokinins and to increase the availability of nitrogen, phosphorus and iron in the soil (Cendale, Gonzáles, Cuásquer, Alzate & Rodríguez, 2017;Saeid et al, 2018;Chagas Junior 2022b).…”