Inoculum density, temperature, and genotype effects on in vitro growth promotion and epiphytic and endophytic colonization of tomato (Lycopersicon esculentum L.) seedlings inoculated with a pseudomonad bacterium

1997 ◽  
Vol 43 (4) ◽  
pp. 354-361 ◽  
Author(s):  
V. K. Pillay ◽  
J. Nowak
Keyword(s):  
Lycopersicon Esculentum ◽  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Bacterial Colonization ◽  
Root Surface ◽  
Inoculum Density ◽  
Dual Culture ◽  
Pseudomonas Sp

The effects of inoculum density (0, 4.6 × 107, 4.2 × 108, and 8.8 × 108 cfu∙mL−1), temperature (10, 20, and 30 °C), and plant genotype (cultivars Celebrity, Blazer, Scotia, and Mountain Delight) on bacterial colonization and plant growth promotion were investigated in a gnotobiotic system. An in vitro dual culture of tomato (Lycopersicon esculentum L.) plantlets and a Pseudomonas sp., strain PsJN, were used. Epiphytic (external) and endophytic (internal) bacterial populations were determined to evaluate plantlet colonization. Shoot and root biomass of bacterized plantlets was significantly higher (p ≤ 0.05) than that of nonbacterized controls. Growth promotion was best with inoculum densities of 3 × 108 – 7 × 108 cfu∙mL−1 at 20 °C, particularly in the early maturing cultivars Blazer and Scotia. Lower inoculum densities were required to maximize root growth (approximately 1 × 108 cfu∙mL−1) than shoot growth (approximately 3 × 108 cfu∙mL−1). Shoot surface populations did not vary with inoculum density or temperature, but the bacterium colonized the shoot exterior of cultivars Celebrity, Mountain Delight, and Scotia better than cultivar Blazer. The root surface populations increased linearly with increasing inoculum density (within a range of 107–108 cfu∙mL−1), decreased with increasing temperatures (from 10 to 30 °C), and were higher for the main season cultivar Celebrity than for cultivars Blazer, Scotia, and Mountain Delight. Populations of shoot endophytes did not vary with initial inoculum density or genotype but were affected by temperature; the highest colonization was at 10 °C. The number of root endophytes was also highest at 10 °C at the inoculum density of approximately 4 × 108 cfu∙mL−1 and did not vary with genotypes. The experiments clearly indicate that there was no relationship between root surface colonization and plant growth promotion. However, the range of inoculum levels (3 × 108 – 7 × 108 cfu∙mL−1) that promoted colonization of the inner root tissues (endophytic) also best promoted plant growth. A possible biostimulation threshold within the tissues of the inoculated plants under conditions favourable to the growth of tomato is proposed.Key words: Pseudomonas sp., tomato, colonization, growth promotion.

scholarly journals Exploitation of endophytic Pseudomonas sp. for plant growth promotion and colonization in rice

2017 ◽  
Vol 9 (3) ◽  
pp. 1310-1316
Author(s):  
Gurjot Kaur ◽  
Poonam Sharma ◽  
Deepika Chhabra ◽  
Kailash Chand ◽  
Gurjit Singh Mangat
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Acc Deaminase ◽  
Pseudomonas Sp ◽  
Bacterial Isolates ◽  
Pgp Traits ◽  
P Solubilization ◽  
Fluorescent Pigment

The present investigation was carried out to exploit bacterial endophytes associated with root and leaf tissue of rice plant for plant growth promotion (PGP) and colonization study in vitro. Total 10 endophytic bacterial isolates (Pseudomonas sp.) were evaluate for PGP traits like P solubilization, production of Indole acetic acid (IAA), siderophore, ACC deaminase, protease, cellulase, fluorescent pigment, urease and denitrification activity. Out of 10 endophytic bacteria 30 %, 60 %, 20 %, 70 %, 10 % and 10 % were positive for siderophore, protease, cellulase, fluorescent pigment, urease and denitrification respectively. Maximum IAA production was recorded with isolate LRBLE7 (18.8 μgml-1) followed by LRBRE4 (16.0 μgml-1) and maximum P-solubilization was recorded with isolate LRBRE4 (5.8 mg 100 ml-1) followed by LRBLE7 (4.4 mg 100 ml-1). ACC deaminase production was recorded with isolate LRBLE6 (O.D=0.352 nm) followed by LRBRE5 (O.D=0.324nm). Three potential isolates (LRBRE4, LRBRE6 and LRBLE7) were selected on the basis of multiple PGP traits and were subjected to colonization study of rice seedling in vitro. Potential bacterial isolates can be exploited for improving growth and productivity in rice under sustainable management system.

Enhancement of verticillium wilt resistance in tomato transplants by in vitro co-culture of seedlings with a plant growth promoting rhizobacterium (Pseudomonas sp. strain PsJN)

1998 ◽  
Vol 44 (6) ◽  
pp. 528-536 ◽  
Author(s):  
V K Sharma ◽  
J Nowak
Keyword(s):  
Plant Growth ◽  
Verticillium Wilt ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Disease Suppression ◽  
Pseudomonas Sp ◽  
Plant Growth Promoting ◽  
Growth Promoting

The potential utilization of a plant growth promoting rhizobacterium, Pseudomonas sp. strain PsJN, to enhance the resistance of tomato transplants to verticillium wilt was investigated. Plant growth and disease development were tested on the disease-susceptible cultivar Bonny Best after Verticillium dahliae infection of tissue culture plantlets bacterized in vitro (by co-culturing with the bacterium) and seedlings bacterized in vivo (after 3 weeks growth in the greenhouse). Significant differences in both disease suppression and plant growth were obtained between in vitro bacterized and nonbacterized (control) plants. The degree of protection afforded by in vitro bacterization depended on the inoculum density of V. dahliae; the best and worst protection occurred at the lowest (103 conidia ·mL-1) and highest (106 conidia ·mL-1) levels, respectively. In contrast, the in vivo bacterized tomatoes did not show plant growth promotion when compared to the nonbacterized control plants. When challenged with Verticillium, significant growth differences between in vivo bacterized plants (26.8% for shoot height) and nonbacterized controls were only seen at the 3rd week after inoculation. Compared with the in vitro inoculation, there was no delay in the verticillium wilt symptom expression, even at the lowest concentration of V. dahliae, by in vivo PsJN inoculation. These results suggest that endophytic colonization of tomato tissues is required for the Verticillium-resistance responses. Plant growth promotion preceeds the disease-resistance responses and may depend on the colonization thresholds and subsequent sensitization of hosts.Key words: Pseudomonas sp., plant growth promoting rhizobacterium, Verticillium dahliae, tomato, colonization, plant growth promotion, disease suppression.

EFFICACY OF RHIZOBACTERIA ON PLANT GROWTH PROMOTION AND DISEASE SUPPRESSION IN VITRO

2012 ◽  
pp. 525-532 ◽  
Author(s):  
S. Velivelli ◽  
E. O'Herlihy ◽  
B. Janczura ◽  
B. Doyle Prestwich ◽  
J. Ghyselinck ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Disease Suppression

scholarly journals Potential for Plant Growth Promotion of Rhizobacteria Associated withSalicorniaGrowing in Tunisian Hypersaline Soils

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Francesca Mapelli ◽  
Ramona Marasco ◽  
Eleonora Rolli ◽  
Marta Barbato ◽  
Hanene Cherif ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Crop Production ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Growth Promotion ◽  
Arid Ecosystems ◽  
Acetic Acid Production ◽  
Halotolerant Bacteria ◽  
Microbiome Composition

Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres ofSalicorniaplants and bulk soils were collected fromSebkhetandChotthypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated withSalicorniaroot system. A large collection of 475 halophilic and halotolerant bacteria was established fromSalicorniarhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP) features. TwentyHalomonasstrains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activitiesin vitroat 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using agfp-labelled strain it was possible to demonstrate thatHalomonasis capable of successfully colonisingSalicorniaroots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.

scholarly journals Isolation, Biochemical and Genomic Characterization of Glyphosate Tolerant Bacteria to Perform Microbe-Assisted Phytoremediation

2021 ◽  
Vol 11 ◽  
Author(s):  
Francisco Massot ◽  
Panagiotis Gkorezis ◽  
Jonathan Van Hamme ◽  
Damian Marino ◽  
Bojana Spirovic Trifunovic ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Large Scale ◽  
Agricultural Soils ◽  
Growth Promotion ◽  
Sole Source ◽  
Bacterial Strains ◽  
Positive Effects ◽  
Assisted Phytoremediation

The large-scale use of the herbicide glyphosate leads to growing ecotoxicological and human health concerns. Microbe-assisted phytoremediation arises as a good option to remove, contain, or degrade glyphosate from soils and waterbodies, and thus avoid further spreading to non-target areas. To achieve this, availability of plant-colonizing, glyphosate-tolerant and -degrading strains is required and at the same time, it must be linked to plant-microorganism interaction studies focusing on a substantive ability to colonize the roots and degrade or transform the herbicide. In this work, we isolated bacteria from a chronically glyphosate-exposed site in Argentina, evaluated their glyphosate tolerance using the minimum inhibitory concentration assay, their in vitro degradation potential, their plant growth-promotion traits, and performed whole genome sequencing to gain insight into the application of a phytoremediation strategy to remediate glyphosate contaminated agronomic soils. Twenty-four soil and root-associated bacterial strains were isolated. Sixteen could grow using glyphosate as the sole source of phosphorous. As shown in MIC assay, some strains tolerated up to 10000 mg kg–1 of glyphosate. Most of them also demonstrated a diverse spectrum of in vitro plant growth-promotion traits, confirmed in their genome sequences. Two representative isolates were studied for their root colonization. An isolate of Ochrobactrum haematophilum exhibited different colonization patterns in the rhizoplane compared to an isolate of Rhizobium sp. Both strains were able to metabolize almost 50% of the original glyphosate concentration of 50 mg l–1 in 9 days. In a microcosms experiment with Lotus corniculatus L, O. haematophilum performed better than Rhizobium, with 97% of glyphosate transformed after 20 days. The results suggest that L. corniculatus in combination with to O. haematophilum can be adopted for phytoremediation of glyphosate on agricultural soils. An effective strategy is presented of linking the experimental data from the isolation of tolerant bacteria with performing plant-bacteria interaction tests to demonstrate positive effects on the removal of glyphosate from soils.

scholarly journals Biocontrol of Macrophomina phaseolina (Tassi) Goid causing charcoal rot disease in Lycopersicon esculentum L. by using multi species bacterial consortia

2021 ◽  
Vol 22 (3) ◽  
pp. 441-449
Author(s):  
Pradeep Kumar ◽  
Sandeep Kumar ◽  
R.C. Dubey
Keyword(s):  
Lycopersicon Esculentum ◽  
Plant Growth ◽  
Growth Promotion ◽  
Macrophomina Phaseolina ◽  
Growth And Yield ◽  
Pseudomonas Sp ◽  
Bacillus Sp ◽  
Bacterial Strains ◽  
Plant Growth Promoting ◽  
Growth Promoting

Plant growth-promoting bacterial strains (LEP1-LEP31) were isolated from rhizosphere of Lycopersicon esculentum L. (Tomato) and screened for their plant growth promoting (PGP) activities. On the basis of morphological, physiological, biochemical, carbon source utilization and molecular characterization, these strains were identified as Pseudomonas sp., Azotobacter sp. and Bacillus sp. For antagonistic activities all the strains were subject to the chitinase activities by the development of clear halo around the inoculated bacterial spots when loaded on chitin (0.2%) supplemented mediumBased on pot and field trial results of individual strains and consortium application, it may be concluded that all the three strains i.e. Pseudomonas sp. LEP17, Azotobacter sp. strain LEP21 and Bacillus sp. strain LEP25 showed plant growth promoting effects. The growth promotion provided by these strains was apparently related to improve shoot and root development, which resulted in better nutrient uptake capability and suppression of plant pathogen. All these three strains were superior in this regard because they provided the best and most consistent effects on growth and yield of L. esculentum. All these strains Pseudomonas sp. LEP17, Azotobacter sp. strain LEP21, Bacillus sp. strain LEP25 and their consortium seems to be suitable for use as a plant growth promoting and improvement of growth and yield

scholarly journals An In vitro Study of Bio-Control and Plant Growth Promotion Potential of Salicaceae Endophytes

2017 ◽  
Vol 8 ◽  
Author(s):  
Shyam L. Kandel ◽  
Andrea Firrincieli ◽  
Pierre M. Joubert ◽  
Patricia A. Okubara ◽  
Natalie D. Leston ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
In Vitro Study ◽  
Vitro Study

scholarly journals Compost Inoculated with Fungi from a Mangrove Habitat Improved the Growth and Disease Defense of Vegetable Plants

2020 ◽  
Vol 13 (1) ◽  
pp. 124
Author(s):  
Fuad Ameen ◽  
Ali A. Al-Homaidan
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
C:N Ratio ◽  
Chemical Properties ◽  
Plant Diseases ◽  
Mangrove Forests ◽  
Mangrove Fungi ◽  
Disease Defense

Municipal organic wastes could be exploited as fertilizers, having been given the ability to suppress plant diseases by the inoculation of the waste with certain fungi in the composting process. Our aim was to develop a novel fertilizer using composting in combination with fungi associated with mangrove forests. Nine fungal species were isolated from a mangrove forest habitat and screened for their activity against five phytopathogenic fungi, their plant-growth promotion ability, and their phosphate solubilization ability. Two fungal isolates, Penicillium vinaceum and Eupenicillium hirayama, were inoculated into organic waste before the composting experiment. After 90 days, the physico-chemical properties of the compost (color, moisture, pH, C:N ratio and cation exchange capacity (CEC)) indicated the maturity of the compost. The C:N ratio decreased and the CEC value increased most in the compost with the inoculum of both mangrove fungi. The vegetable plants grown in the mangrove fungi-inoculated composts had a higher vigor index than those grown in the control compost. The seeds collected from the plants grown in the fungi-inoculated composts had higher disease defense ability than the seeds collected from the control compost. The results indicated that the properties of the fungi shown in vitro (antagonistic and plant-growth promotion) remained in the mature compost. The seeds of the plants acquired disease defense ability, which is a remarkable observation that is useful in sustainable agriculture.

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