scholarly journals Identification of Plant Growth Promoting Rhizobacteria That Improve the Performance of Greenhouse-Grown Petunias under Low Fertility Conditions

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1410
Author(s):  
Kaylee A. South ◽  
Nathan P. Nordstedt ◽  
Michelle L. Jones
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Genomic Analysis ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Low Fertility ◽  
Plant Performance ◽  
Flower Bud ◽  
Plant Growth Promoting ◽  
Growth Promoting

The production of greenhouse ornamentals relies on high fertilizer inputs to meet scheduling deadlines and quality standards, but overfertilization has negative environmental impacts. The goals of this study were to identify plant-growth-promoting rhizobacteria (PGPR) that can improve greenhouse ornamental crop performance with reduced fertilizer inputs, and to identify the best measurements of plant performance for assessing the beneficial impact of PGPR on ornamentals. A high-throughput greenhouse trial was used to identify 14 PGPR isolates that improved the flower/bud number and shoot dry weight of Petunia × hybrida ‘Picobella Blue’ grown under low fertility conditions in peat-based media. These 14 PGPR were then applied to petunias grown under low fertility conditions (25 mg L−1 N). PGPR-treated plants were compared to negative (untreated at 25 mg L−1 N) and positive (untreated at 50, 75, 100, and 150 mg L−1 N) controls. Multiple parameters were measured in the categories of flowering, vegetative growth, and vegetative quality to determine the best measurements to assess improvements in ornamental plant performance. Caballeronia zhejiangensis C7B12-treated plants performed better in almost all parameters and were comparable to untreated plants fertilized with 50 mg L−1 N. Genomic analysis identified genes that were potentially involved in plant growth promotion. Our study identified potential PGPR that can be used as biostimulants to produce high-quality greenhouse ornamentals with lower fertilizer inputs.

A gnotobiotic bioassay for studying interactions between potatoes and plant growth-promoting rhizobacteria

1997 ◽  
Vol 43 (9) ◽  
pp. 801-808 ◽  
Author(s):  
Kenneth L. Conn ◽  
George Lazarovits ◽  
Jerzy Nowak
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Potato Cultivar ◽  
Fold Increase ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Single Node ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Potato Plantlets

A gnotobiotic bioassay, using potato plantlets derived from single-node explants and grown in test tubes containing potato nodal cutting medium (PNCM), was found to be highly useful for investigations of direct growth promotion by a nonfluorescent Pseudomonas sp. strain PsJN. Strain PsJN was used to optimize and evaluate this bioassay for purposes of screening other rhizosphere bacteria and identification of Tn5 mutants of strain PsJN deficient in growth-promoting properties. The selection of potato cultivar used in this bioassay was critical, as growth promotion of potatoes by strain PsJN was cultivar specific. Inoculated plantlets of cultivars Norchip, Kennebec, Shepody, and Chaleur showed, in root dry weight, a five- to eight-fold increase, two- to three-fold increase, no response, and a decrease of 50%, respectively. Haulm dry weight followed similar trends but was not as consistent an indicator of growth promotion. Bioassay results were not altered to any extent by minor changes in PNCM composition or by slight changes in temperature and light conditions. A rapid method for preparation of bacterial suspensions and inoculation of explants was developed. Inoculation of three explants taken from 6-week-old stock plantlets of cv. Kennebec for each Tn5 transconjugate of strain PsJN (total of 1500 transconjugates) enabled the elimination of 93% of those isolates that retained growth-promoting activity. The remaining 7% of isolates were retested and seven were confirmed to have lost growth-promoting ability. Bacteria from different genera were also screened with this bioassay. None of these bacteria increased the growth of potato plantlets, but several inhibited root and haulm growth.Key words: plant growth-promoting rhizobacteria, gnotobiotic, tissue culture, nonfluorescent pseudomonad, bacterium, potato.

scholarly journals Rhizobacterial Inoculants Increase Root and Shoot Growth in ‘Tifway’ Hybrid Bermudagrass

2014 ◽  
Vol 32 (3) ◽  
pp. 149-154 ◽  
Author(s):  
R. Murphey Coy ◽  
David W. Held ◽  
Joseph W. Kloepper
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Growth Promotion ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Strains ◽  
Agronomic Crops ◽  
Plant Growth Promoting ◽  
Bacterial Treatment ◽  
Growth Promoting

Plant growth-promoting rhizobacteria (PGPR) are non-pathogenic, beneficial bacteria that colonize seeds and roots of plants and enhance plant growth. Although there has been extensive PGPR research with agronomic crops, there has been little emphasis on development of PGPR for grasses in pastures or as turf. Accordingly, experiments were conducted to evaluate novel bacterial inoculants for growth promotion in ‘Tifway’ hybrid bermudagrass. Replicated laboratory and greenhouse experiments evaluated effects of various PGPR mixtures, each with 3 to 5 PGPR strains and applied as weekly root inoculations, in comparison to nontreated plants. Growth promotion was assessed by measuring foliar growth from 3 to 8 wk and root growth at 8 wk after the first treatment. In all experiments, at least one bacterial treatment of bermudagrass resulted in significantly increased top growth and greater root growth (length, surface area, volume, or dry weight). PGPR blends 20 and MC3 caused the greatest growth promotion of roots and shoots. These results suggest that the bacterial strains could be used in strategies to reduce nitrogen or water inputs to turf.

scholarly journals Perlakuan Rizobakteri Pemacu Pertumbuhan Tanaman (RPPT) dengan Beberapa Tingkat Kerapatan Inokulum Rizobakteri Terhadap Viabilitas dan Vigor Benih Cabai Merah Kadaluarsa (Capsicum annuum L.)

2020 ◽  
Vol 4 (1) ◽  
pp. 229-238
Author(s):  
Dayang Rahmanita Simanjuntak ◽  
Halimursyadah Halimursyadah ◽  
Syamsuddin Syamsuddin
Keyword(s):  
Plant Growth ◽  
Capsicum Annuum ◽  
Seed Treatment ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Seed Vigor ◽  
Inoculum Density ◽  
Plant Growth Promoting ◽  
Actinobacillus Suis ◽  
Growth Promoting

Abstrak. Biological seed treatment merupakan salah satu perlakuan benih menggunakan mikroorganisme seperti rizobakteri pemacu pertumbuhan tanaman (RPPT). Penelitian ini bertujuan untuk mengetahui jenis rizobakteri dan kerapatan inokulum yang dapat meningkatkan viabilitas dan vigor benih cabai kadaluarsa. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) pola faktorial dengan 2 faktor dan 3 ulangan. Faktor pertama adalah jenis rizobakteri (R) terdiri atas lima taraf yaitu R1: Necercia sp; R2:Bacillus polymixa; R3: Actinobacillus suis; R4: Azotobacter sp; R5: Pseudomonas capacia. Faktor kedua adalah kerapatan inokulum rizobakteri terdiri dari tiga taraf yaitu K1: 107 cfu/ml; K2: 108 cfu/ml; K3: 109 cfu/ml. Hasil penelitian ini menunjukkan bahwa perlakuan benih menggunakan rizobakteri jenis Necercia sp dengan kerapatan inokulum 108 cfu/ml nyata meningkatkan vigor benih pada tolok ukur  indeks vigor yaitu 40% dan Pseudomonas capacia dengan kerapatan inokulum 109 cfu/ml juga merupakan kombinasi perlakuan terbaik dalam meningkatkan berat kering kecambah normal yaitu 69,33 mg.Treatment Of Plant Growth Promoting Rhizobacteria (PGPR)With Multiple Levels of Rhizobacteria Inoculum Density On Viability and Vigor Of Expired Red Chilli Seeds (Capsicum annuum L.Abstract. Biological seed treatment is one of the seed treatment using microorganisms such as plant growth-promoting rhizobacteria (PGPR). This study aims to determine the type of rhizobacteria and inoculum density that can increase the viability and vigor of expired chili seeds. This research uses Completely Randomized Design (CRD) factorial pattern with 2 factors and 3 replications. The first factor is the type of rhizobacteria (R) consists of five levels, namely R1: Necercia sp; R2: Bacillus polymixa; R3: Actinobacillus suis; R4: Azotobacter sp; R5: Pseudomonas capacia. The second factor is the density of rhizobacteria inoculum consisting of three levels namely K1: 107 cfu/ml; K2: 108 cfu/ml; K3: 109 cfu/ml. The results of this study showed that the seed treatment using the Necercia sp-type rizobacteria with 108 cfu/ml inoculum density significantly increased the seed vigor on the vigor index benchmark of 40% and Pseudomonas capacia with 109cfu/ml inoculum density was also the best treatment combination in increasing dry weight normal sprout is 69,33 mg. 

Rhizobium leguminosarum as a plant growth-promoting rhizobacterium: direct growth promotion of canola and lettuce

1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes
Keyword(s):  
Acetic Acid ◽  
Plant Growth ◽  
Rhizobium Leguminosarum ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting ◽  
Direct Growth ◽  
Early Seedling ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid

Early seedling root growth of the nonlegumes canola (Brassica campestris cv. Tobin, Brassica napus cv. Westar) and lettuce (Lactuca saliva cv. Grand Rapids) was significantly promoted by inoculation of seeds with certain strains of Rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. The growfh-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. Auxotrophic Rhizobium mutants requiring tryptophan or adenosine (precursors for indole-3-acetic acid and cytokinin synthesis, respectively) did not promote growth to the extent of the parent strain. The findings of this study demonstrate a new facet of the Rhizobium–plant relationship and that Rhizobium leguminosarum can be considered a plant growth-promoting rhizobacterium (PGPR).Key words: Rhizobium, plant growth-promoting rhizobacteria, PGPR, indole-3-acetic acid, cytokinin, roots, auxotrophic mutants.

Colonization and growth promotion of outplanted spruce seedlings pre-inoculated with plant growth-promoting rhizobacteria in the greenhouse

2000 ◽  
Vol 30 (6) ◽  
pp. 845-854 ◽  
Author(s):  
Masahiro Shishido ◽  
Christopher P Chanway
Keyword(s):  
Plant Growth ◽  
Seedling Growth ◽  
Picea Glauca ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Population Declines ◽  
Growth Responses ◽  
Relative Growth Rates ◽  
Plant Growth Promoting ◽  
Growth Promoting

Seeds of two hybrid spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.) ecotypes were inoculated with one of six plant growth-promoting rhizobacteria (PGPR) strains previously shown to be able to stimulate spruce growth in controlled environments. The resulting seedlings were grown in the greenhouse for 17 weeks before outplanting at four reforestation sites. Inoculation with five of the six strains caused significant seedling growth promotion in the greenhouse, which necessitated analysis of relative growth rates (RGR) to evaluate seedling performance in the field. Four months after outplanting, most strains enhanced spruce shoot or root RGRs in the field, but seedling growth responses were strain specific. For example, Pseudomonas strain Ss2-RN significantly increased both shoot and root RGRs by 10-234% at all sites, but increases of 28-70% were most common. In contrast, Bacillus strain S20-R was ineffective at all outplanting sites. In addition, seedlings inoculated with four of the six strains had significantly less shoot injury than control seedlings at all sites. Evaluation of root colonization by PGPR indicated that bacterial population declines were not related to spruce growth response variability in the field. Our results indicate that once plant growth promotion is induced in the greenhouse, seedling RGR can increase by more than 100% during the first growing season in the field. However RGR increases of 21-47% were more common and may be more representative of the magnitude of biomass increases that can result from PGPR inoculation.

Field evaluation of asparagus crowns and germinating seeds inoculated with plant growth-promoting rhizobacteria

2009 ◽  
Vol 89 (6) ◽  
pp. 1133-1138
Author(s):  
S M Liddycoat ◽  
D J Wolyn
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Field Evaluation ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Asparagus Officinalis ◽  
Shoot Height ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Germinating Seeds

Plant growth-promoting rhizobacteria (PGPR) have the ability to enhance growth and establishment by reducing stress ethylene, or providing exogenous indol-3-acetic acid (IAA), nitrogen, iron, or phosphorus. In previous greenhouse studies, PGPR inoculation of asparagus seeds or seedlings enhanced growth under optimal and water stress conditions. Experiments were conducted in this study to determine if PGPR could provide benefits to transplanted crowns and germinating seeds in the field. Plant growth-promoting rhizobacteria did not positively affect shoot height, count, or diameter of inoculated crowns, or percent germination and seedling dry weight of inoculated seeds. The limitations of using PGPR in the field and potential for future success are discussed.Key words: Asparagus officinalis, Pseudomonas , water stress, drought, irrigation

scholarly journals Characterization of Selected Plant Growth-Promoting Rhizobacteria and Their Non-Host Growth Promotion Effects

2021 ◽  
Author(s):  
Di Fan ◽  
Donald L. Smith
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Content Type ◽  
Host Growth ◽  
Plant Growth Promoting ◽  
Growth Promoting

There are pressing needs to reduce the use of agrochemicals, and PGPR are receiving increasing interest in plant growth promotion and disease protection. This study follows up our previous report that the four newly isolated rhizobacteria promote the growth of Arabidopsis thaliana .

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