Diversity, activity, and effectiveness of Rhizobium bacteria as plant growth promoting rhizobacteria (PGPR) isolated from Dieng, central Java

Abstract

Background and Objectives: This study was aimed to isolate Rhizobium spp., from the plant rhizosphere and to investigate their effects on the growth of peanut (Arachis hypogaea L.) as plant growth-promoting rhizobacteria (PGPR).
 Materials and Methods: The isolates were characterized using YEMA, YEMA + Congo Red, and YEMA + Bromothymol blue (BTB) media. The Rhizobium was tested qualitatively for their ability to produce indole acetic acid (IAA), siderophores, proteases, nitrogenases as well as phosphate solubilizing activity. A greenhouse experiment was carried out to elucidate the effect of Rhizobium inoculation on Arachis hypogaea L. growth.
 Results: Eleven isolates were obtained in YEMA media and they were red-pink in the YEMA + Congo Red media. The YEMA + BTB test showed that 2 isolates were slow-growing and the rest were fast-growing isolates. Seven isolates produced siderophores, 5 were capable of phosphate solubilizing, 9 isolates produced protease enzyme, 4 isolates could produce IAA, and 7 isolates could fix nitrogen. The B1 and the combination of some high trait-isolate treatments in Y gave the best results on Arachis hypogaea L. growth.
 Conclusion: These isolates can be developed as biological fertilizer agents for the peanut plant.

Enhancing systemic resistance in faba bean (Vicia faba L.) to Bean yellow mosaic virus via soil application and foliar spray of nitrogen-fixing Rhizobium leguminosarum bv. viciae strain 33504-Alex1

“…Many phytohormones, such as brassinosteroids, cytokinins, enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, ethylene, gibberellins, IAA, jasmonates, lipo-chito-oligossacharide Nod factors, lumichrome, rhizobitoxine, and riboflavin, were synthesized and released during the symbiotic interaction process between rhizobia and legumes ( Jaiswal et al, 2021 ). Such compounds can directly or indirectly stimulate plant growth and may promote plant adaptation to various stresses ( Purwaningsih et al, 2021 ). Rhizobium is a natural PGPR in the rhizosphere used in farming to enhance legume crops’ growth through mutually beneficial relationships ( Allito et al, 2021 ; Boivin et al, 2021 ).…”

Preliminary symbiotic performance of indigenous soybean (Glycine max)-nodulating rhizobia from agricultural soils of Tanzania

“…The varied capacities of rhizobia isolates in N 2 fixation are indicated by the difference in the diameter of the N 2 fixation zones (Aloo, 2021). The media color around the rhizobia colonies changes from blue to yellow due to the production of acidic metabolites during their growth on NFM (Baldani et al, 2014;Akintokun et al, 2019), which also indicates that the tested rhizobia are fast growers (Purwaningsih et al, 2021). Although there was no statistical significance between TZSR27A, TZSR25A, and the three isolates TZSR39C, TZSR41B, and TZSR56C, but the best isolate, TZSR27A, in terms of larger diameter of N 2 fixation .…”

Sustainable intensification of smallholder farming systems in Sub-Saharan Africa and South Asia

“…The varied capacities of rhizobia isolates in N 2 fixation are indicated by the difference in the diameter of the N 2 fixation zones (Aloo, 2021). The media color around the rhizobia colonies changes from blue to yellow due to the production of acidic metabolites during their growth on NFM (Baldani et al, 2014;Akintokun et al, 2019), which also indicates that the tested rhizobia are fast growers (Purwaningsih et al, 2021). Although there was no statistical significance between TZSR27A, TZSR25A, and the three isolates TZSR39C, TZSR41B, and TZSR56C, but the best isolate, TZSR27A, in terms of larger diameter of N 2 fixation .…”