scholarly journals Role of Growth-Promoting Bacteria as Biocontrol Agent Against Root Knot Nematode of Tomato

2021 ◽  
Vol 14 (4) ◽  
pp. 1557-1563
Author(s):  
Sandeep Kumar Gupta
Keyword(s):  
Extracellular Enzymes ◽  
Plant Growth Promoting Rhizobacteria ◽  
Biocontrol Agents ◽  
Bacterial Isolates ◽  
Root Knot Nematode ◽  
Nematode Management ◽  
Farming Community ◽  
Plant Growth Promoting ◽  
Growth Promoting

There are significant losses which have occurred in crops due to the infestation of plant parasitic nematode which are known as hidden enemy due to their presence in rhizosphere and their infection site on the roots. Synthetic nematicidal control is an effective strategy to combat this biotic stress but an inappropriate and deficient application of chemical pesticides have an adverse effect on soil micro-flora and fauna. Due to the environmental and regulatory pressure, use of potential biocontrol agents is the new approach for nematode management by the farming community. For this study, four potential rhizobacteria from different habitats BHU1, BHU2, BHU3 and BHU4 were assessed for their antagonistic activities against Meloidogyne incognita infecting tomato plant. These were characterized on the basis of their morphological and biochemical activities. In vitro screening of bacterial isolates was conducted in a 25-microwell plate by addition of second stage juvenile (J2) of M. incognita with nematode application. Among four bacteria,, three potential antagonistic bacteria were able to kill nematode within 24 hours. Mortality percentage of J2 M. incognita observed in sterile distilled water selected bacterial isolates ranged from 23.33 to 100% in 3h to 24h periods. Moreover, all bacterial isolates except BHU2 isolate were found positive for production of extracellular enzymes like catalase, oxidase, chitinase, amylase and gelatinase which favour effective biopesticide activity of bacteria. Further selected isolates of bacteria associated with tomato have shown a great potential as biocontrol agents against root-knot nematode in tomato during pot experiment. Based on the fact stated above, the current research focused on plant growth promoting rhizobacteria based nematodes biocontrol strategies with direct and indirect mechanism of PGPR for nematode management.

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.

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 Screening for Potential Plant Growth-Promoting Rhizobacteria (PGPR) Associated with Five Musa spp. Cultivars in SOCCSKSARGEN, Philippines

2018 ◽  
Vol 1 ◽  
pp. 5
Author(s):  
Giuseppe Haydn Lacorte ◽  
Remedios S. Flamiano ◽  
Malona V. Alinsug ◽  
Paolo M. Tagaloguin
Keyword(s):  
Microbial Population ◽  
Phosphate Solubilization ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Isolates ◽  
Iaa Production ◽  
Phosphate Solubilizers ◽  
Rhizospheric Bacteria ◽  
Nitrogen Fixers ◽  
Plant Growth Promoting ◽  
Growth Promoting

Rhizospheric bacteria (PGPR) associated with 5 banana cultivars planted in SOCCSKSARGEN were studied. Microbial population in newly established and old plantation was compared. Bacteria were purified and their beneficial characteristics were determined. This study was able to collect one hundred twenty (120) bacterial isolates, 20 (17%) of which were nitrogen-fixers, nineteen (19/20) were phosphate solubilizers and seventeen (17/20) were IAA producers. From this study, five bacterial isolates coded PE05, RS10, PE11, PE13, and PE18 were found positive for nitrogen fixation, phosphate solubilization and IAA production which may be further evaluated for their potential application in the formulation of biofertilizers for banana cultivation. Read full article here.

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 Use of plant growth-promoting rhizobacteria (PGPR) and soil organic amendments for the management of root diseases complex of uridbean

2013 ◽  
Vol 54 (1) ◽  
pp. 65-70 ◽  
Author(s):  
I. A. Siddiqui ◽  
S. S.. Shaukat ◽  
S. Ehteshamul-Haque
Keyword(s):  
Root Rot ◽  
Organic Amendment ◽  
Organic Amendments ◽  
Plant Growth Promoting Rhizobacteria ◽  
Macrophomina Phaseolina ◽  
Root Knot Nematode ◽  
Neem Cake ◽  
Root Diseases ◽  
Plant Growth Promoting ◽  
Growth Promoting

Efficacy of two strains of <i>Pseudomonas aeruginosa</i> (Pa-5 and IE-2) and <i>Bacillus subtilis</i> isolate alone or in conjunction with neem cake or <i>Datura fastuosa</i> was tested for the management of three soilbrne root-infecting fungi including <i>Macrophomina phaseolina, Fusarium solani</i> and <i>Rhizoctonia solani</i> and the root-knot nematode, <i>Meloidogyne javanica</i> on uridbean. Biocontrol bacteria used in combination with either neem cake or <i>D.fastuosa</i> gave better control of the root-rot and root-knot infection with the enhancement of growth of uridbean compared to the use ofeither component alone. Neem cake l% w/w mixed with <i>P.aeruginosa</i> strain IE-2 caused greatest inhibition of the root-knot development due to <i>M.javanica, P.aeruginosa</i> and <i>B.subtilis</i> used with organic amendment also increased <i>Bradyrhizobium</i>-nodules in the root system.

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