Variable responses on early development of shallot (Allium ascalonicum) and mustard (Brassica juncea) plants to Bacillus cereus inoculation

Abstract

Aim: Auxin, a phytohormone secreted by plant growth-promoting rhizobacteria is one of the direct mechanisms vital for plant growth promotion. A laboratory experiment was conducted to observe the effect of IAA-producing and non-IAAproducing diazotroph Bacillus cereus strains on early growth of shallot (Allium ascalonicum) and mustard (Brassica juncea) plants. Methodology and Results: Treatments evaluated were as follows: Control = uninoculated, no inoculation, UPMLH1 = IAA-producing B. cereus UPMLH1, and UPMLH24 = non-IAA-producing B. cereus UPMLH24. Inoculation with IAAproducing B. cereus UPMLH1 significantly increased shallot adventitious roots (root number and length) and shoot growth (19 to 54% increment). Inoculation of non-IAA-producing B. cereus UPMLH24 did not significantly improve growth of adventitious roots of shallot as compared to uninoculated control, except its shoot (up to 40% increase). However, primary roots and shoot growth of mustard plants significantly increased through inoculation with IAAproducing and non-IAA-producing strains (14 to 73% increment). Conclusion, Significance and Impact of Study: The results indicated that exogenous IAA secreted by B. cereus UPMLH1 might have play an important role in inducing roots of shallot bulbs and it may have a variable promotional effect depending on plant species.

Plant growth-enhancing traits of rhizobacteria isolated from brinjal, okra, and leaf mustard

“…BB2, BA37 and SA19 reduced germination percentage, whereas the remaining isolates increased the seed germination. This finding is in line with other researchers who reported various effects of rhizobacteria inoculation on seed germination, either stimulative (Aziz et al 2012, Fatemeh et al 2014, no effect (Pramanik et al 2018), whereas the adverse effect was reported by Arslan and Akkaya (2020). This diverse effect might be due to differences in the production of phytohormone as phytohormone influences seed germination.…”

Selecting the most effective plant growth-promoting bacteria from oil palm (Elaeis guineensis Jacq) roots

“…Failure of some rhizobacteria to promote plant growth inoculated to non-host plant has been reported by Thokchom et al (2017) who found inoculation of mandarin by host strain enhanced plant growth compared to non-host strain. Moreover, the interaction between soil bacteria and plants can be either beneficial, harmful, or neutral depending on the species of the bacteria and types of plant (Turan et al, 2016) thus demonstrated variable plant responses to inoculation (Aziz et al, 2012). Even though only isolate EN9 indicates some promising effect on plant growth, other isolates demonstrated no deleterious effect upon plant growth (no significance difference at p>0.05 over control).…”

Efficiency of Bacillus mucilaginosus isolated from the soil in dissolving potassium in its microenvironment

“…One hundred grams of soil samples were collected from the previously mentioned regions and kept in polyethylene bags 20x 40 cm. Soil samples were pretreated with CaCO3 at a ratio of 10:1 soil: CaCO3 and kept at an ambient temperature 37ºC to reduce the contamination with molds and yeast, as described by (Aziz, 2022).…”