Characterization and Identification of Native Plant Growth-Promoting Bacteria Colonizing Tef (Eragrostis Tef) Rhizosphere During the Flowering Stage for A Production of Bio Inoculants

Abstract

The Plant Growth-Promoting Rhizobacteria (PGPR) are the free-living plant roots colonizing bacteria that improve soil fertility, stimulating plant growth, and protecting plants from biotic and abiotic stress factors. The present study was conducted to characterize and identify native PGP bacteria colonizing tef rhizosphere during the flowering stage for a production of bio inoculant. For this concern, 426 samples of different varieties of tef roots and rhizosphere soils were collected. A total of 457 rhizobacteria were isolated and characterized for PGP traits, biocontrol properties, and abiotic stress tolerance ability. 12 rhizobacterial species were identified using the Biolog bacterial identification system. Among these, the majority of the identified bacterial species were utilized different carbon sources that similar to plant root exudates i.e. carbohydrates, carboxylic acids, amide, and amine.Seed germination and seedling growth test were conducted using four identified bacterial species having excellent plant growth-promoting, biotic and abiotic stress tolerance properties, and 100 percent tef seeds germination result occurred on 3 rd and 4 th day after inoculation. shoot and root length of inoculated seeds was measured on last day of the experiment to determine the effect of PGP bacteria on tef crops growth enhancement and increase mean shoots and root length up to 3 and 2.6 cm respectively in comparison to control. PGP bacterial species or strains can be used as bio inoculants to replacing chemical fertilizers for sustaining agricultural productivity and production without affecting soil fertility, living organisms, and their environment.

Impact of Co-Inoculation with Rhizobium leguminosarum and some Plant Growth Promoting Rihzobacteria against Rhizoctonia solani and Fusarium oxysporum Infected Faba Bean

“…The direct growth promoting mechanisms includes (i) N2 fixation; (ii) solubilization of mineral phosphate and zinc; (iii) sequestration of iron by production of siderophores; (iv) production of phytohormones such as auxins, cytokinins and gibberellins; (v) production of the enzyme 1-aminocyclopropane -1-carboxylate (ACC) deaminase which hydrolyses ACC, the immediate precursor of ethylene in plants. Lowering of ethylene concentration in seedlings promoted the stimulation seedling root length (Tsegaye et al, 2019). Plant Growth Promoting Rhizobacteria also support plant growth indirectly, by improving growth restricting conditions via (i) production of antibiotics; (ii) depletion of iron from the rhizosphere; (ii) production of fungal cell wall lysing enzymes ß-(1, 3) -glucanase and chitinase; (iii) synthesis of antifungal metabolites such as cyanide ion; (iv) competition for infection sites on roots; (v) induction of systemic resistance (Aeron et al, 2011 andSaraf et al, 2014).…”

Characterization of heavy metal-resistant rhizobia and non-rhizobia isolated from root nodules of Trifolium sp. in a lead and zinc mining area

“…These microbial lytic enzymes are also known to play a role in antagonizing various plant pathogenic fungi by degrading their cell wall (Siddiqui 2006). Tsegaye et al (2019) found that PGPR that synthesizes one or more of these extracellular enzymes has biocontrol ability against a range of plant pathogenic fungi and bacteria and improves crop yield.…”

Dominance of Bacillus species in the wheat (Triticum aestivum L.) rhizosphere and their plant growth promoting potential under salt stress conditions

“…After incubation, the plates were stained with 1% iodine solution for 15 min, then washed with water. Pectinase production was indicated by the formation of halo zone around the colonies ( Tsegaye et al, 2019b ).…”