scholarly journals Antagonism of plant growth promoting rhizobacteria against the causal agent of the vascular wilting of tomato

2020 ◽  
Vol 22 (2) ◽  
pp. 35-43
Author(s):  
Narmer Fernando Galeano Vanegas ◽  
Sandra Maria Marulanda Moreno ◽  
Beatriz Elena Padilla Hurtado ◽  
Javier Guillermo Mantilla Afanador ◽  
Nelson Ceballos Aguirre ◽  
...  

Use of biotechnological potential of native microorganisms as bio-inputs is having a great impact on agricultural systems. Plant Growth Promoting Rhizobacteria (PGPR), in addition to their beneficial effect on plant growth and on the availability of soil elements, also have an antagonistic effect against different pathogens. In this study, growth promotion mechanisms with emphasis on the antagonism of PGPR isolated from sugarcane and tomato crops were evaluated. Antagonism against Fusarium oxysporum f.sp lycopersici (Fol) was determined by dual tests, inhibition of germination and production of chitinases and endoglucanases. 52 isolates were evaluated and according to their results in dual tests 10 were selected for further analysis. Isolate GIBI127 showed the best percentage of Inhibition Germination (IG) of Fol (59.29%). Then, a selection index was calculated using results from gi, dual tests and growth promotion mechanisms to select five best isolates. Finally, these bacteria were evaluated for chitinases and endoglucanases production using Miller´s method. As a result, strain GIBI419 (Burkholderia cepacia) showed a higher production of these enzymes. Selected isolates have antagonistic potential along with plant growth promotion characteristics, which can be used for the development of microbial inoculants which allow the establishment of agricultural systems for tomato cultivation that are sustainable, efficient, and environmentally friendly.

1995 ◽  
Vol 24 (3) ◽  
pp. 179-185 ◽  
Author(s):  
B. Schippers ◽  
R. J. Scheffer ◽  
B. J. J. Lugtenberg ◽  
P. J. Weisbeek

Plant growth-promoting rhizobacteria (PGPRs) have the potential to contribute significantly to the development of sustainable agricultural systems. Our understanding at the molecular level of the interactions between these microorganisms, the plant and the environment is growing rapidly, facilitating the development of microbial products. However, their development is hampered by the legislative restrictions on their use and consequently high costs. This is especially true because biocontrol agents are often specific to crops, pathogens and soil types. Nevertheless, promising new products for the improvement of plant establishment and plant growth, such as ‘BioCoat ’ for radish seeds, have entered the market.


Vegetalika ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 512
Author(s):  
Nanda Dwi Hafri ◽  
Endang Sulistyaningsih ◽  
Arif Wibowo

Salah satu upaya penanganan penyakit moler bawang merah dilakukan melalui aplikasi Trichoderma. Aplikasi Trichoderma pada bawang merah memiliki beberapa keunggulan, yaitu mampu mensintesis hormon pertumbuhan tanaman. Terdapat jenis mikroba lain yang juga mampu meningkatkan fitohormon pada tanaman, yaitu Plant Growth Promoting Rhizobacteria (PGPR). Tujuan dari penelitian ini adalah untuk mengetahui dan menentukan isolat PGPR yang memiliki pengaruh paling baik terhadap pertumbuhan dan hasil bawang merah varietas Crok Kuning di lahan sawah. Penelitian ini menggunakan Rancangan Acak Kelompok Lengkap (RAKL) faktor tunggal dengan tiga blok sebagai ulangan. Faktor perlakuan yang digunakan adalah lima isolat PGPR, yaitu: Bp.25.7 Bacillus subtilis, BrSG.5 Bacillus amyloliquofaciens, Bp.25.2 Bacillus methylotrophicus, BrsM.4 Burkholderia cepacia, danBp.25.6 Bacillus amyloliquofaciens dengan dua kontrol, yaitu kontrol positif berupa Trichoderma dan kontrol negatif tanpa aplikasi perlakuan. Hasil penelitian menunjukkan bahwa pemberian perlakuan isolat Bp.25.2 Bacillus methylotrophicus pada bawang merah menyebabkan Laju Asimilasi Bersih (LAB) bawang merah lebih tinggi dibandingkan dengan pemberian perlakuan empat isolat PGPR lainnya maupun kontrol, tetapi sama baiknya dengan pemberian perlakuan Trichoderma. LAB yang tinggi menyebabkan Laju Pertumbuhan Tanaman (LPT) bawang merah dengan pemberian perlakuan Bp.25.2 Bacillus methylotrophicus yang lebih tinggi dibandingkan dengan BrSG.5 Bacillus amyloliquofaciens dan Bp.25.6 Bacillus amyloliquofaciens, tetapi sama baiknya dengan pemberian perlakuan dua isolat PGPR lainnya, kontrol, maupun Trichoderma. Pemberian aplikasi lima isolat PGPR sama baiknya dengan aplikasi Trichoderma dalam meningkatkan pertumbuhan tanaman bawang merah pada variabel luas permukaan daun dan bobot kering total dibandingkan kontrol. Peningkatan variabel pertumbuhan ini tidak diikuti oleh peningkatan variabel hasil dan produktivitas bawang merah tidak berbeda nyata antar perlakuan.


2020 ◽  
Vol 273 ◽  
pp. 111118 ◽  
Author(s):  
Zobia Khatoon ◽  
Suiliang Huang ◽  
Mazhar Rafique ◽  
Ali Fakhar ◽  
Muhammad Aqeel Kamran ◽  
...  

2019 ◽  
Vol 47 (3) ◽  
Author(s):  
Vladimir Ion ROTARU ◽  
Luxita RISNOVEANU

The growth of legume plants is usually improved by the rhizobacteria inoculation under low phosphorus (P) and alleviation of P nutrition plays important role in plant drought stress response. The aim of this study was to assess the comparative efficacy of two plant growth promoting rhizobacteria namely Burkholderia cepacia B36 and Enterobacter radicincitans D5/23T combined with two sources of phosphates in soybean (Glycine max L.) under low water supply. Plants were grown under P soluble versus insoluble P fertilization for comparing the effects of soybean inoculation on growth, uptake and use efficiency of phosphorus under moderate drought stress. At the beginning of flowering, half of plants was subjected to low water supply (35% water holding capacity, WHC) for 12 days while control plants were well watered - 70% WHC. The plants were harvested at the end of drought and physiological traits and P contents were analyzed. The inoculation treatments showed better plant growth and nutrient uptake when compared to uninoculated control. The application of the Burkholderia cepacia was more efficiently in terms plant growth than E. radicincitans especially under insoluble phosphates. Phosphorus concentrations of shoots and roots increased with both bacterial strains. The bacterial inoculation has much better stimulatory effect on nutrient uptake by soybean fertilized with insoluble phosphates. Study findings indicate that the combined application of PGPR (Burkholderia cepacia B36) and P amendments has the potential to improve P nutrition and growth of soybean cultivated on P-deficient soil under well-watered as well as moderate drought condition.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********


1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes

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.


2000 ◽  
Vol 30 (6) ◽  
pp. 845-854 ◽  
Author(s):  
Masahiro Shishido ◽  
Christopher P Chanway

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.


Author(s):  
Di Fan ◽  
Donald L. Smith

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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