Aim: This study was conducted to formulate and evaluate the efficacy of a composite: coir pith + starch + plant-growth-promoting rhizobacteria (PGPR), in sustaining the survival and growth of Zea mays (maize) seeds cultivated under flood stress.
Place and Duration of Study: Department of Microbiology Laboratory, Federal University Otuoke, Bayelsa State, Nigeria, between May and July 2024.
Methodology: Rhizobacteria were isolated, screened for plant-growth-promoting (PGP) traits; phosphate solubilisation and indole-3-acetic acid (IAA) production and further tested for PGP activity via seed germination bioassay. Composites were prepared by homogenizing coir pith, starch gel and standardized PGPR inoculum at a ratio of 2:24:20 (w/v), pelleted and dried at 28 oC. The efficacy of the composites was examined in a pot experiment by measuring shoot length (SL), root length (RL) and plant height (PH), of the treated maize seeds. Treatments were conducted in two sets (single composite pellet and 4 composite pellets); Set 1 (seeds + 1 composite pellet/pot, Control 1 and Control 2), Set 2 (seeds + 4 composite pellets/pot, Control 1 and Control 2). Controls 1 and 2 were; seeds + coir pith + starch only and maize seeds only, respectively. Set 1 was monitored for 2 weeks, and Set 2 for 7 days. Flood conditions were simulated by saturating the pots with water, without drainage, for 3 days.
Results: Five rhizobacteria were isolated; LCE tested positive for IAA production and phosphate solubilisation, SPP tested positive for IAA production only, and C tested positive for phosphate solubilization only. The growth performance of treated maize seeds under waterlogged condition in Set 1 indicated that the Control 1 (maize seeds + 1 coir pith + starch only pellet) was more effective than Control 2 and the other composites. The treatments in Set 1 did not support maize seed growth throughout the two-week monitoring period, except control 1 (maize seeds + 1 coir pith +starch only) which sustained seed survival and growth for 2 weeks. One way ANOVA indicated that the mean growth for control 1 was the same across the weeks as the p-value (p = 0.658) is greater than the 5% significance level (α = 0.05). In Set 2, at day 7, the observed survival and growth of maize seeds treated resulted from the application of 4 coir pith+starch+LCE (Priestia flexa) pellets. The mean SL, RL and PH recorded for the seeds were 2.6±0.2, 3.6±0.45 and 15.9±0.45 cm, respectively. LCE was identified by 16S rRNA sequencing as Priestia flexa.
Conclusion: This study demonstrates the potential of coir pith+ starch+Priestia flexa to mitigate waterlogging stress, sustain survival and growth of Zea mays seedlings.
Background: Acer oblongum (Himalayan maple) is an ecologically and socio-economically important Himalayan tree species. Poor natural regeneration and inconsistent seed germination in its natural habitats constrain its propagation, conservation, and nursery-scale multiplication.
Aim: The present study aimed to evaluate the effects of plant growth-promoting rhizobacteria (PGPR) and plant growth-promoting fungi (PGPF), used as seed bio-priming agents, on germination percentage and early seedling vigour of A. oblongum under in vitro conditions.
Study Design: The study was conducted using a completely randomised design (CRD) to evaluate the effects of microbial treatments on germination percentage, mean germination time, germination value, peak value, germination index, root length, shoot length, and total seedling length. In vitro analyses were performed using the selected PGPR and PGPF isolates. The experiment comprised seven treatments: an untreated control, P. gessardii, P. mosselii, P. fluorescens, B. subtilis, a bacterial consortium, and Trichoderma spp. Bio-primed seeds were incubated in a germinator, and germination was monitored daily throughout the experimental period.
Results: Microbial treatments significantly affected germination parameters and early seedling performance. The highest germination percentage was observed in seeds treated with Trichoderma (38.40%), followed by Pseudomonas mosselii (34.40%), compared with the control (28.00%). Root length, shoot length, collar diameter, and seed vigour index were highest in seeds treated with Trichoderma, followed by the consortium, compared with the control.
Conclusion: Among the tested treatments, Trichoderma spp. was the most effective and produced the highest germination percentage, germination value, peak value, germination index, root length, shoot length, total seedling length, and seed vigour index in Acer oblongum.
R. Juwantha, N. Namitha, Shivani Semwal et al.· Annual Research & Review...· 0 citations
Plant growth-promoting rhizobacteria consortia are used in the growth and augmentation of Mustard CS61 (Brassica juncea) under saline conditions to discover novel genes associated with stress tolerance and plant growth–promoting traits.
M. Bhat, Mayuri K Auti, Prajval Poojary· Discover Biotechnology· 0 citations
Background: Maize (Zea mays L.) is one of the world's most important cereal crops, and improving its productivity while reducing dependence on chemical fertilizers has become a major goal of sustainable agriculture. The potential role of plant growth promoting rhizobacteria (PGPR) as a biofertilizer evolved as appropriate substitute to neutralize adverse environmental impacts wielded by manmade agrochemical.
Objective: This study aimed to evaluate the effects of Pseudomonas fluorescens and Bacillus subtilis, individually and in combination, on the growth and yield of maize compared with conventional NPK fertilization.
Methods: A field experiment was conducted during the 2025 growing season at the Field Crops Research Station, College of Agriculture, University of Samarra, using a Randomized Complete Block Design (RCBD) with three replicates. Six treatments were evaluated: Untreated control (T1), Pseudomonas fluorescens (T2), Bacillus subtilis (T3), combined inoculation (P. fluorescens + B. subtilis) (T4), combined inoculation with NPK fertilizer (T5), and NPK fertilizer (20:20:20) only (T6). Vegetative growth and yield-related traits were recorded and statistically analyzed.
Results: Inoculation of plants with PGPR bacteria resulted in a significant improvement in both vegetative growth and yield compared to the untreated control group. Pseudomonas fluorescens (T2) exhibited the highest vegetative growth rate, recording the highest plant height (148.00 cm), leaf area (365.00 cm²), leaf area index (2.63), and number of grains per spike (688 grains) compared control group recorded (92.33 cm), (10.67 plant⁻¹), (151.73 cm²), (0.70) respectively. Bacillus subtilis (T3), achieved the highest productivity, producing the largest number of spikes per plant (2.67 spikes) and the highest spike weight (283.50 g) compared control group recorded (2.00) and (161.60 g).
Conclusion: The use of PGPR, and especially Pseudomonas fluorescens and Bacillus subtilis as potential biofertilisation agents is a promising sustainable alternative to chemical fertilisation that can enhance maize growth and production, while decreasing dependence on mineral fertilisers.
Waser saad Khalaf, Ahmed waleed Abdulrahman· International Journal of Bio...· 0 citations
The productivity of sweet corn must be continuously improved to meet increasing market demand. Inorganic fertilizers may reduce soil fertility. The application of (PGPR) derived from bamboo roots, which function as biofertilizers and biostimulants by enhancing nutrient availability and stimulating plant growth. Appropriate plant spacing is also an important agronomic practice for optimizing the use of light, water, nutrients, and growing space. This study aimed to evaluate the interaction between plant spacing and bamboo root PGPR concentration on the growth and yield of sweet corn. The experiment was conducted in Potroyudan Village, Jepara from December 2024 to March 2025 using a two-factor Randomized Complete Block Design (RCBD). The first factor consisted of three plant spacings (75 × 40 cm, 75 × 30 cm, and 75 × 20 cm), while the second factor included three PGPR concentrations (0, 25, and 50 ml L⁻¹). Data were analyzed using analysis of variance (ANOVA) followed by Duncan's Multiple Range Test (DMRT) at the 5% significance level. The interaction between plant spacing and PGPR concentration significantly affected plant height only at 6 weeks after planting. Plant spacing significantly influenced stem diameter, cob weight with husk, and cob length without husk. The 75 × 40 cm spacing produced the highest cob weight (276.48 g) and longest cob length (19.44 cm). PGPR concentration showed no significant effect, although 25 ml L⁻¹ tended to produce better growth and yield. Overall, plant spacing contributed more to sweet corn productivity than bamboo root PGPR under the conditions of this study.
T. Prakoso, Heny Alpandari, Abdullah Alfalakhi· Nabatia· 0 citations
Brazilian cattle production relies predominantly on pasture systems, many of which are degraded by nutrient depletion, particularly nitrogen deficiency. Plant growth-promoting bacteria (PGPB) offer a sustainable strategy to improve pasture productivity, but their effects are often host-specific and remain poorly explored in Paspalum. This study evaluated the effect of inoculation with Azospirillum brasilense strains CNPSo 2083 (=Ab-V5) and CNPSo 2084 (=Ab-V6) and Pseudomonas fluorescens strain CNPSo 2719 (=CCTB 03), applied by seed inoculation or leaf spray, on the root morphology and shoot growth of four Paspalum accessions under controlled axenic greenhouse conditions, evaluated in an early growth stage at 35 days after emergence. Genotype-specific responses were the central finding of this study: Paspalum malacophyllum BGP-293 showed negligible responses to inoculation, whereas BGP-486—of the same species—increased root dry weight by up to 43% and root tissue density by up to 30% in all inoculated treatments. In Paspalum regnellii BGP-112, seed inoculation produced stronger root responses than foliar spray, increasing root dry weight by up to 38% and root area by up to 40%. In Paspalum rojasii BGP-149, inoculation induced root architectural remodeling without increasing root biomass—root area increased by up to 92% and total root length by up to 97%, relative to the control—indicating an efficient root-foraging strategy. P. fluorescens favored root-foraging traits and tissue density, whereas A. brasilense preferentially stimulated root-hair elongation. These accession-level contrasts, rather than a single generalizable trend, are the main contribution of this work: they support tailored, genotype-specific PGPB strategies for sustainable tropical pastures.
Beatriz Cortellini Ferranti, Gabriela da Silva Guimarães, A. B. Rondina et al.· Plants· 0 citations
This study evaluated the effects of plant growth-promoting rhizobacteria (PGPR) and drought-stress timing on the growth, yield, and physiological responses of shallot ( Allium ascalonicum L.) cultivated in saline soil. The experiment was conducted using a factorial randomized block design with PGPR concentrations of 0, 20, and 40 mL L⁻¹ and drought-stress timing consisting of no stress, early growth stress (1–14 DAP), vegetative stress (15–28 DAP), and bulb formation stress (29–42 DAP). The final soil EC reached 6 dS m⁻¹, while soil moisture during drought periods declined to 30–50%. PGPR improved plant length, leaf area, tiller number, plant dry weight, and net assimilation rate. PGPR at 40 mL L⁻¹ was more effective for vegetative growth, whereas 20 mL L⁻¹ tended to enhance proline and flavonoid accumulation. Drought during early and vegetative phases caused the greatest reductions in growth and yield. These findings indicate that PGPR supports shallot performance in saline soil, but its effectiveness depends strongly on water availability during critical growth phases.
Affan Iga Pratama, Andi Kurniawan, A. Karyawati et al.· Ecological Engineering &...· 0 citations
