scholarly journals Evaluation of diverse range microbes for their plant growth promoting abilities and their pesticide compatibility

2021 ◽  
pp. 47-58
Author(s):  
Tulja Sanam ◽  
S. Triveni ◽  
J. Satyanaryana ◽  
Sridhar Goud Nerella ◽  
K. Damodara Chari ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Atomic Absorption Spectrophotometry ◽  
In Vitro Assays ◽  
Bacterial Isolates ◽  
Diverse Range ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Bacillus Isolate

Plant growth-promoting rhizobacteria (PGPR) contribute to an increase in crop yield through an environmentally friendly method, therefore eight rhizospheric bacteria, two of each genera Bacillus, Pseudomonas, Azotobacter and Azospirillum were examined for their efficacy to solubilize mineral nutrients using atomic absorption spectrophotometry and a flame photometer. Their potency to produce phytohormones, synthesis biocontrol components and their compatibility with pesticides using in vitro assays was studied. All of the chosen bacterial isolates proved positive for the above-mentioned Plant Growth Promoting traits. Among the eight bacterial isolates Pseudomonas isolate P69 showed the highest phosphorous solubilization efficiency of 190.91 % and another isolate P48 produced a maximum of 27.63µg mL-1 of gibberellic acid, Bacillus isolate B120 could solubilize maximum amount of ZnO and ZnCO3 accounting for 21.3ppm and 25.9ppm, respectively, not merely in terms of solubilization when compared to the other isolates, B120 produced the highest levels of HCN (77.33 ppm TCC) and siderophores (48.87psu). On day 9 after inoculation, Azotobacter isolate AZB17 performed effectively in potassium solubilization of 6.25g mL-1 with a pH drop to 3.83. The Azospirillum isolate ASP25 outperformed all other isolates in terms of IAA production (22.64g mL-1) and Bacillus isolate B365 was found to be more compatible with eight different pesticides used in the field at varying concentrations. All of these factors point to the possibility of using these bacterial isolates B120, P48, P69, AZB17, and ASP25 as biofertilizers in sustainable agriculture.

scholarly journals Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Alemayehu Getahun ◽  
Diriba Muleta ◽  
Fassil Assefa ◽  
Solomon Kiros
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
In Vitro Assays ◽  
Plant Tolerance ◽  
Bacterial Strains ◽  
Root And Shoot Length ◽  
Plant Growth Promoting ◽  
Growth Promoting

Drought stress (DS) is the most impacting global phenomenon affecting the ecological balance of a particular habitat. The search for potential plant growth-promoting rhizobacteria (PGPR) capable of enhancing plant tolerance to drought stress is needed. Thus, this study was initiated to evaluate the effect of inoculating Acacia abyssinica seedlings with PGPR isolated from rhizosphere soil of Ethiopia to enhance DS tolerance. The strains were selected based on in vitro assays associated with tolerance to drought and other beneficial traits such as salinity, acidity, temperature, heavy metal tolerances, biofilm formation, and exopolysaccharide (EPS) production. The strains with the best DS tolerance ability were selected for the greenhouse trials with acacia plants. The results indicate that out of 73 strains, 10 (14%) were completely tolerant to 40% polyethylene glycol. Moreover, 37% of the strains were strong biofilm producers, while 66 (90.41%) were EPS producers with a better production in the medium containing sucrose at 28 ± 2°C and pH 7 ± 0.2. Strains PS-16 and RS-79 showed tolerance to 11% NaCl. All the strains were able to grow in wider ranges of pH (4–10) and temperature (15–45°C) and had high tolerance to heavy metals. The inoculated bacterial strains significantly ( p ≤ 0.05 ) increased root and shoot length and dry biomass of acacia plants. One of the strains identified as P. fluorescens strain FB-49 was outstanding in enhancing DS tolerance compared to the single inoculants and comparable to consortia. Stress-tolerant PGPR could be used to enhance acacia DS tolerance after testing other phytobeneficial traits.

Sulfur-oxidizing bacteria as plant growth promoting rhizobacteria for canola

1991 ◽  
Vol 37 (7) ◽  
pp. 521-529 ◽  
Author(s):  
Susan J. Grayston ◽  
James J. Germida
Keyword(s):  
Plant Growth ◽  
Elemental Sulfur ◽  
Sulfur Oxidation ◽  
Plant Growth Promoting Rhizobacteria ◽  
Growth Chamber ◽  
Bacterial Isolates ◽  
Plant Growth Promoting ◽  
Sulfur Oxidizing ◽  
Growth Promoting

Canola (Brassica napus) has a high sulfur requirement during vegetative growth and exhibits symptoms of sulfur deficiency when cropped on Saskatchewan soils low in plant available sulfur. Elemental sulfur (S0) is frequently used as a fertilizer to alleviate this deficiency. The potential of sulfur-oxidizing microorganisms to enhance the growth of canola in S0 fertilized soils was assessed. Sulfur-oxidizing bacteria and fungi were isolated from the rhizosphere and rhizoplane of canola grown in four different Saskatchewan soils under growth chamber conditions. Of 273 bacterial isolates, 245 (89.7%) oxidized S0 to thiosulfate or tetrathionate in vitro, and 133 (48.7%) oxidized S0 to sulfate; 70 fungal isolates oxidized S0 to sulfate. Eighteen bacterial isolates demonstrating the highest in vitro sulfur oxidation were tested as seed inoculants under growth chamber conditions, with S0 as sulfur source. Fourteen isolates increased canola leaf size measured at the bud stage of growth, and seven isolates increased root and pod dry weights at maturity. Three of the 14 isolates were also able to stimulate canola leaf area in the presence of plant available sulfate. The shoot material from canola inoculated with two of these isolates contained more iron, sulfur, and magnesium than uninoculated canola. Three of the 14 isolates inhibited the growth of the canola fungal pathogens, Rhizoctonia solani AG2-1, R. solani AG4, and Leptosphaeria maculans "Leroy." Another isolate was antagonistic towards both R. solani strains and another inhibited the growth of R. solani AG2-1 and L. maculans "Leroy." Thus some sulfur-oxidizing isolates appear to stimulate canola growth due to the enhancement of mineral nutrient uptake, whereas in other cases antibiosis towards canola pathogens may also be involved. Key words: elemental sulfur, oxidation, canola, rhizosphere, plant growth promoting rhizobacteria.

scholarly journals Consortium of Plant Growth – Promoting Rhizobacteria Enhances Oilseed Rape (Brassica Napus L.) Growth Under Normal And Saline Conditions

2021 ◽  
Author(s):  
Maria Swiontek Brzezinska ◽  
Joanna Świątczak ◽  
Anna Wojciechowska ◽  
Aleksandra Burkowska-But ◽  
Agnieszka Kalwasińska
Keyword(s):  
Plant Growth ◽  
Crop Yields ◽  
Fungal Infections ◽  
Plant Growth Promoting Rhizobacteria ◽  
Growth Promoter ◽  
Bacterial Isolates ◽  
Brassica Napus L ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Development of a preparation, which stimulates plant growth under normal and saline conditions, and protects against fungal infections, would increase crop yields and reduce damage in agriculture. This study was conducted using bacterial isolates from rape rhizosphere as a plant growth promoter and an alternative to chemical fertilizers. Three from fifty bacterial isolates: B14 (Pseudomonas grimontii), B16 (Sphingobacterium kitahiroshimense), and B19 (Microbacterium oxydans) showed the best in vitro plant growth – promoting (PGP) characteristics. B14 strain inhibited the growth of B. cinerea, C. acutatum, and P. lingam and B14 - inoculated plants had the best ability to grow in salt concentrations of 100 mM NaCl. Moreover, B14, B16 and B19 isolates coded for several genes involved in PGP activities, aimed at improving nutrient availability, resistance to abiotic stress, and fungal pathogen suppression. Microbial consortium (B14, B16, and B19) had the best effect on rape growth, significantly increasing chlorophyll content index, shoot length and number of live leaves, compared to the untreated control and single inoculant treatments. Consortium also induced the plants tolerance to salt stress. The genomic information as well as the observed traits, and beneficial attributes towards rape, make the rhizobacterial consortium an ideal candidate for further development as biofertilizers.

scholarly journals Integrated Genomic and Greenhouse Assessment of a Novel Plant Growth-Promoting Rhizobacterium for Tomato Plant

2021 ◽  
Vol 12 ◽  
Author(s):  
Maria Chiara Guerrieri ◽  
Andrea Fiorini ◽  
Elisabetta Fanfoni ◽  
Vincenzo Tabaglio ◽  
Pier Sandro Cocconcelli ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Nutrition ◽  
Growth Regulation ◽  
Root Length Density ◽  
Plant Growth Promoting Rhizobacteria ◽  
Conventional Management ◽  
Tomato Field ◽  
Plant Growth Promoting ◽  
Growth Promoting

Plant growth promoting rhizobacteria (PGPR) can display several plant-beneficial properties, including support to plant nutrition, regulation of plant growth, and biocontrol of pests. Mechanisms behind these effects are directly related to the presence and expression of specific genes, and different PGPR strains can be differentiated by the presence of different genes. In this study we reported a comprehensive evaluation of a novel PGPR Klebsiella variicola UC4115 from the field to the lab, and from the lab to the plant. The isolate from tomato field was screened in-vitro for different activities related to plant nutrition and growth regulation as well as for antifungal traits. We performed a functional annotation of genes contributing to plant-beneficial functions previously tested in-vitro. Furthermore, the in-vitro characterization, the whole genome sequencing and annotation of K. variicola UC4115, were compared with the well-known PGPR Azospirillum brasilense strain Sp7. This novel comparative analysis revealed different accumulation of plant-beneficial functions contributing genes, and the presence of different genes that accomplished the same functions. Greenhouse assays on tomato seedlings from BBCH 11–12 to BBCH > 14 were performed under either organic or conventional management. In each of them, three PGPR inoculations (control, K. variicola UC4115, A. brasilense Sp7) were applied at either seed-, root-, and seed plus root level. Results confirmed the PGP potential of K. variicola UC4115; in particular, its high value potential as indole-3-acetic acid producer was observed in increasing of root length density and diameter class length parameters. While, in general, A. brasilense Sp7 had a greater effect on biomass, probably due to its high ability as nitrogen-fixing bacteria. For K. variicola UC4115, the most consistent data were noticed under organic management, with application at seed level. While, A. brasilense Sp7 showed the greatest performance under conventional management. Our data highlight the necessity to tailor the selected PGPR, with the mode of inoculation and the crop-soil combination.

scholarly journals Plant growth-promoting activity in bean plants of endophytic bacteria isolated from Echeveria laui

2021 ◽  
Vol 5 (2) ◽  
pp. 65
Author(s):  
Anderson Emmer ◽  
João Arthur Dos Santos Oliveira ◽  
Andressa Domingos Polli ◽  
Julio Cesar Polonio ◽  
Leonardo Hamamura Alves ◽  
...  
Keyword(s):  
Plant Growth ◽  
Endophytic Bacteria ◽  
Arid Environment ◽  
Bacterial Isolates ◽  
Phaseolus Vulgaris L ◽  
Bean Plants ◽  
Plant Growth Promoting ◽  
Plant Growth Promoting Activity ◽  
Growth Promoting

Echeveria laui (Crassulaceae) is commonly commercialized due to its drought-tolerance capacity and to its rosette-shaped aesthetics. Since endophytes associated with plants from a dry or arid environment have scarcely been analyzed as yet, current research comprises the isolation of leaf endophytic bacteria from E. laui (one five-year-old and one two-year-old plants) investigating plant growth-promoting endophytic bacteria which may solubilize phosphate, fix nitrogen, produce exopolysaccharides/IAA and antagonize phytopathogens. Isolation by the maceration methodology provided a colonization rate of 1.98 x109 CFU g-1 for the two-year-old plant and 1.14 x 1010 CFU g-1 for the five-year-old one. All 40 isolates evaluated showed in vitro plant growth-promoting agent’s abilities, with emphasis on EG04, ELG18, and ELP06.  The capacity of the three best bacterial isolates were evaluated under greenhouse conditions in common and black bean (Phaseolus vulgaris L.) plants. Based on the sequencing of the 16S rRNA region and phylogenetic analysis, the three endophytes were identified as Pantoea sp. (ELG04 and ELG18) and Erwinia sp. (ELP06). Under greenhouse conditions, statistically significant differences were found among the plants treated with the three endophytes when compared to control plants for fresh and dry shoot, root biomass and length.

scholarly journals Isolation and screening of multifunctional rhizobacteria from the selected sites of Madhupur, Narshingdi and Mymensingh, Bangladesh

2015 ◽  
Vol 2 (1) ◽  
pp. 1-8
Author(s):  
Moonmoon Nahar Asha ◽  
Atiqur Rahman ◽  
Quazi Forhad Quadir ◽  
Md Shahinur Islam
Keyword(s):  
Plant Growth ◽  
Crop Production ◽  
Plant Growth Promoting Rhizobacteria ◽  
N Fixation ◽  
National Botanical Research Institute ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Botanical Research ◽  
Plant Growth Promoting Traits

A laboratory experiment was performed to isolate some native rhizobacteria that could be used as bioinoculants for sustainable crop production. A total of 43 rhizobacteria were isolated from undisturbed plant rhizosphere soils of three different locations of Bangladesh and evaluated their plant growth promoting traits, both direct and indirect. The study has screened out isolates on the basis of their phosphorous solubilization and nitrogen (N) fixation. The phosphate solubilization assay in National Botanical Research Institute of Phosphate (NBRIP) medium revealed that 12 bacterial isolates were able to solubilize tricalcium phosphate and the rhizobacteria M25 showed best performance with a PSI of 3.33 at 5 day. Exactly 47% (20 isolates) of the isolated rhizobacteria were able to grow in N-free Winogradsky’s medium, which is an indication of potential N2-fixers. Among the 20 potential N-fixers, 15 were able to grow within 24 hours of incubation indicating that they are more efficient in Nfixation. The present study successfully isolated and characterized 43 rhizobacteria. Some of these isolated rhizobacteria have potential plant growth promoting traits and are potential plant growth promoting rhizobacteria (PGPR) candidate. Considering all plant growth promoting traits, the isolate F37 was the best followed by M6. However, further experiments are needed to determine the effectiveness of these isolates under in vitro and different field conditions to understand the nature of interaction with the plant and environment.Res. Agric., Livest. Fish.2(1): 1-8, April 2015

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