scholarly journals Evaluation of a Newly Identified Endophytic Fungus, Trichoderma phayaoense for Plant Growth Promotion and Biological Control of Gummy Stem Blight and Wilt of Muskmelon

2021 ◽  
Vol 12 ◽  
Author(s):  
Wipornpan Nuangmek ◽  
Worawoot Aiduang ◽  
Jaturong Kumla ◽  
Saisamorn Lumyong ◽  
Nakarin Suwannarach

Gummy stem blight and wilt are known to cause enormous losses to the global production of muskmelon (Cucumis melo). In this study, the potential of endophytic fungi isolated from leaves of Siam weed (Chromolaena odorata) was investigated for the inhibition of mycelial growth of Stagonosporopsis cucurbitacearum and Fusarium equiseti. Twenty-one fungal isolates were obtained. The results indicated that a fungal isolate UP-L1I3 displayed the highest percentage in terms of inhibition of the mycelial growth of F. equiseti and S. cucurbitacearum at 90.80 and 81.60%, respectively. Consequently, this isolate was selected for its potential ability to promote plant growth and control gummy stem blight and wilt in muskmelon seedlings. Morphological and multilocus phylogenetic analyses revealed that the isolate UP-L1I3 was a new species that has been described herein as Trichoderma phayaoense. Pathogenicity test confirmed that F. equiseti and S. cucurbitacearum were the cause of gummy stem blight and wilt disease in muskmelon seedlings, respectively. However, no disease symptoms were observed in seedlings inoculated with T. phayaoense. It was found that T. phayaoense could be used preventively in muskmelon seedlings that were inoculated with F. equiseti and S. cucurbitacearum, which could then reduce the impact on the disease severity index. T. phayaoense was also effective in improving plant development by increasing plant height, as well as shoot and root dry weight values. Moreover, T. phayaoense could effectively increase weight, diameter, and the circumference and total soluble solid of fruit without having a negative effect on fruit quality parameters. Additionally, T. phayaoense was able to tolerate a commonly applied fungicide (metalaxyl) in recommended dosages for field applications.

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Geetha Rajendran ◽  
Maheshwari H. Patel ◽  
Sanket J. Joshi

One of the ways to increase the competitive survivability of rhizobial biofertilizers and thus achieve better plant growth under such conditions is by modifying the rhizospheric environment or community by addition of nonrhizobial nodule-associated bacteria (NAB) that cause better nodulation and plant growth when coinoculated with rhizobia. A study was performed to investigate the most commonly associated nodule-associated bacteria and the rhizospheric microorganisms associated with theFenugreek(Trigonella foenum-graecum) plant. Isolation of nonrhizobial isolates from root nodules ofFenugreekwas carried out along with the rhizospheric isolates. About 64.7% isolates obtained fromFenugreeknodules were gram-negative coccobacilli, 29.41% were gram-positive bacilli, and all rhizospheric isolates except one were gram-positive bacilli. All the isolates were characterized for their plant growth promoting (PGP) activities. Two of the NAB isolates M2N2c and B1N2b (Exiguobacterium sp.) showed maximum positive PGP features. Those NAB isolates when coinoculated with rhizobial strain—S. meliloti, showed plant growth promotion with respect to increase in plant’s root and shoot length, chlorophyll content, nodulation efficiency, and nodule dry weight.


2017 ◽  
Vol 66 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Jian Zhang ◽  
Peng Cheng Wang ◽  
Ling Fang ◽  
Qi-An Zhang ◽  
Cong Sheng Yan ◽  
...  

Phosphorus is a major essential macronutrient for plant growth, and most of the phosphorus in soil remains in insoluble form. Highly efficient phosphate-solubilizing bacteria can be used to increase phosphorus in the plant rhizosphere. In this study, 13 isolates were obtained from waste mushroom residues, which were composed of cotton seed hulls, corn cob, biogas residues, and wood flour. NBRIP solid medium was used for isolation according to the dissolved phosphorus halo. Eight isolates produced indole acetic acid (61.5%), and six isolates produced siderophores (46.2%). Three highest phosphate-dissolving bacterial isolates, namely, M01, M04, and M11, were evaluated for their beneficial effects on the early growth of tomato plants (Solanum lycopersicum L. Wanza 15). Strains M01, M04, and M11 significantly increased the shoot dry weight by 30.5%, 32.6%, and 26.2%, and root dry weight by 27.1%, 33.1%, and 25.6%, respectively. Based on 16S rRNA gene sequence comparisons and phylogenetic positions, strains M01 and M04 belonged to the genus Acinetobacter, and strain M11 belonged to the genus Ochrobactrum. The findings suggest that waste mushroom residues are a potential resource of plant growth-promoting bacteria exhibiting satisfactory phosphate-solubilizing for sustainable agriculture.


mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Dario X. Ramirez-Villacis ◽  
Omri M. Finkel ◽  
Isai Salas-González ◽  
Connor R. Fitzpatrick ◽  
Jeffery L. Dangl ◽  
...  

ABSTRACT Glyphosate is a commonly used herbicide with a broad action spectrum. However, at sublethal doses, glyphosate can induce plant growth, a phenomenon known as hormesis. Most glyphosate hormesis studies have been performed under microbe-free or reduced-microbial-diversity conditions; only a few were performed in open systems or agricultural fields, which include a higher diversity of soil microorganisms. Here, we investigated how microbes affect the hormesis induced by low doses of glyphosate. To this end, we used Arabidopsis thaliana and a well-characterized synthetic bacterial community of 185 strains (SynCom) that mimics the root-associated microbiome of Arabidopsis. We found that a dose of 3.6 × 10−6 g acid equivalent/liter (low dose of glyphosate, or LDG) produced an ∼14% increase in the shoot dry weight (i.e., hormesis) of uninoculated plants. Unexpectedly, in plants inoculated with the SynCom, LDG reduced shoot dry weight by ∼17%. We found that LDG enriched two Firmicutes and two Burkholderia strains in the roots. These specific strains are known to act as root growth inhibitors (RGI) in monoassociation assays. We tested the link between RGI and shoot dry weight reduction in LDG by assembling a new synthetic community lacking RGI strains. Dropping RGI strains out of the community restored growth induction by LDG. Finally, we showed that individual RGI strains from a few specific phyla were sufficient to switch the response to LDG from growth promotion to growth inhibition. Our results indicate that glyphosate hormesis was completely dependent on the root microbiome composition, specifically on the presence of root growth inhibitor strains. IMPORTANCE Since the introduction of glyphosate-resistant crops, glyphosate has become the most common and widely used herbicide around the world. Due to its intensive use and ability to bind to soil particles, it can be found at low concentrations in the environment. The effect of these remnants of glyphosate in plants has not been broadly studied; however, glyphosate 1,000 to 100,000 times less concentrated than the recommended field dose promoted growth in several species in laboratory and greenhouse experiments. However, this effect is rarely observed in agricultural fields, where complex communities of microbes have a central role in the way plants respond to external cues. Our study reveals how root-associated bacteria modulate the responses of Arabidopsis to low doses of glyphosate, shifting between growth promotion and growth inhibition.


Author(s):  
Rajiv Pathak ◽  
Vipassana Paudel ◽  
Anupama Shrestha ◽  
Janardan Lamichhane ◽  
Dhurva. P. Gauchan

Phosphorous (P) is an essential macronutrient and most soils contain high levels of P. However, its availability to plant is limited by rapid immobilization of phosphorous compounds to insoluble forms and hence plant available forms of P in soils are found in low amounts. Phosphate solubilizing bacteria provide an eco-friendly alternative to convert insoluble phosphates into plant available forms. In the present study, three phosphate solubilizing bacterial isolates (PB-1, PB-4 and VC-01) with visually significant phosphate solubilizing abilities were isolated from tomato rhizosphere soil. In-vitro study in pikovskaya’s agar revealed that isolate PB-1 had the highest phosphate solubilizing ability with a phosphate solubilizing index of 2.08±0.07 followed by isolate VC-01 (1.31±0.09) and PB-4 (1.24±0.08). Isolates were used as bacterial inoculum to assess their ability to promote tomato (Lycopersicon esculentum var. Srijana) seedling and plant growth in in-vitro and greenhouse experiment respectively. Isolate PB-4 showed best growth promotion in seedling assay whereas isolate PB-1 and VC-01 also promoted seedling growth compared to control. In greenhouse experiment however, isolates VC-01 and PB-1 significantly enhanced all parameters (shoot length, root length, shoot and root dry weight) compared to uninoculated control whereas isolate PB-4 had a positive effect on all parameters except root length.Kathmandu University Journal of Science, Engineering and TechnologyVol. 13, No. 2, 2017, page: 61-70


Plants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 120 ◽  
Author(s):  
Mohammad K. Hassan ◽  
John A. McInroy ◽  
Jarrod Jones ◽  
Deepak Shantharaj ◽  
Mark R. Liles ◽  
...  

Plant growth-promoting rhizobacteria (PGPR) are increasingly used in crops worldwide. While selected PGPR strains can reproducibly promote plant growth under controlled greenhouse conditions, their efficacy in the field is often more variable. Our overall aim was to determine if pectin or orange peel (OP) amendments to Bacillus velezensis (Bv) PGPR strains could increase soybean growth and nodulation by Bradyrhizobium japonicum in greenhouse and field experiments to reduce variability. The treatments included untreated soybean seeds planted in field soil that contained Bv PGPR strains and non-inoculated controls with and without 0.1% (w/v) pectin or (1 or 10 mg/200 μL) orange peel (OP) amendment. In greenhouse and field tests, 35 and 55 days after planting (DAP), the plants were removed from pots, washed, and analyzed for treatment effects. In greenhouse trials, the rhizobial inoculant was not added with Bv strains and pectin or OP amendment, but in the field trial, a commercial B. japonicum inoculant was used with Bv strains and pectin amendment. In the greenhouse tests, soybean seeds inoculated with Bv AP193 and pectin had significantly increased soybean shoot length, dry weight, and nodulation by indigenous Bradyrhizobium compared to AP193 without pectin. In the field trial, pectin with Bv AP193 significantly increased the shoot length, dry weight, and nodulation of a commercial Bradyrhizobium japonicum compared to Bv AP193 without pectin. In greenhouse tests, OP amendment with AP193 at 10 mg significantly increased the dry weight of shoots and roots compared to AP193 without OP amendment. The results demonstrate that pectin-rich amendments can enhance Bv-mediated soybean growth promotion and nodulation by indigenous and inoculated B. japonicum.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 695
Author(s):  
Marta Kovač ◽  
Danko Diminić ◽  
Saša Orlović ◽  
Milica Zlatković

Sequoiadendron giganteum Lindl. [Buchholz] is a long-lived tree species endemic to the Sierra Nevada Mountains in California. Due to its massive size and beauty, S. giganteum is a popular ornamental tree planted in many parts of the world, including Europe. Since 2017, scattered branch die-back has been observed on S. giganteum trees in Zagreb, Croatia. Other symptoms included resinous branch cankers, reddish-brown discoloration of the sapwood and, in severe cases, crown die-back. Branches showing symptoms of die-back and cankers were collected from six S. giganteum trees in Zagreb and the aim of this study was to identify the causal agent of the disease. The constantly isolated fungi were identified using morphology and phylogenetic analyses based on the internal transcribed spacer (ITS) of the ribosomal DNA (rDNA), and partial sequencing of two housekeeping genes, i.e., translation elongation factor 1-α (TEF 1-α), and β tubulin 2 (TUB2). The fungi were identified as Botryosphaeria dothidea (Moug.) Ces. and De Not. and Neofusicoccum yunnanense G.Q. Li & S.F. Chen. The pathogenicity test was conducted in a plant growth chamber on S. giganteum seedlings and revealed that N. yunnanense was more aggressive compared to B. dothidea. N. yunnanense was able to reproduce symptoms of canker and die-back and kill plants seven weeks after inoculation whereas B. dothidea produced cankers. To the best of our knowledge, this is the first report of B. dothidea and N. yunnanense causing canker and die-back disease of S. giganteum in Croatia. It is also the first record on the identity and pathogenicity of any fungal species associated with S. giganteum in this country. The study expended the known host range of N. yunnanense to include S. giganteum, which is a valuable ornamental tree in Croatian landscapes. Disease management strategies should be developed to mitigate or reduce the impact of the disease.


2013 ◽  
Vol 59 (8) ◽  
pp. 534-539 ◽  
Author(s):  
Subramaniam Gopalakrishnan ◽  
Srinivas Vadlamudi ◽  
Shravya Apparla ◽  
Prakash Bandikinda ◽  
Rajendran Vijayabharathi ◽  
...  

Five strains of Streptomyces (CAI-17, CAI-68, CAI-78, KAI-26, and KAI-27) were previously reported to have potential for charcoal rot control and plant growth promotion (PGP) in sorghum. In this study, those 5 Streptomyces strains were characterized for their enzymatic activities and evaluated for their PGP capabilities on rice. All the Streptomyces strains were able to produce lipase and β-1,3-glucanase; grew in NaCl (up to 8%), at pH 5–13, and at temperatures 20–40 °C; and were resistant to ampicillin, sensitive to nalidixic acid, and highly sensitive to chloramphenicol, kanamycin, streptomycin, and tetracycline. They were highly tolerant to the fungicide bavistin but were highly sensitive to benlate, benomyl, and radonil. When evaluated on rice in the field, Streptomyces significantly enhanced tiller and panicle numbers, stover and grain yields, dry matter, root length, volume and dry weight, compared with the control. In the rhizosphere at harvest, microbial biomass carbon and nitrogen, dehydrogenase activity, total nitrogen, available phosphorus, and % organic carbon were also found significantly higher in Streptomyces-treated plots than in the control plots. This study further confirms that the selected Streptomyces have PGP activities.


2019 ◽  
Vol 67 (4) ◽  
Author(s):  
Felipe Romero-Perdomo ◽  
Jhonnatan Ocampo-Gallego ◽  
Mauricio Camelo-Rusinque ◽  
Ruth Bonila

In this study, we aimed at examining the potential to stimulate growth in Pennisetum clandestinum using four isolated bacterial strains from soils obtained from a Colombian tropical silvopastoral system. We previously identified genetically the strains and characterized two plant growth promotion activities. We found that the four bacterial strains were phylogenetically associated with Klebsiella sp. (strains 28P and 35P), Beijerinka sp. (37L) and Achromobacter xylosoxidans (E37), based on partial 16S rRNA gene sequencing. Moreover, the in vitro biochemical assays demonstrated that the strains exhibited some plant growth promotion mechanisms such as 1-aminocyclopropane-1-carboxylic acid deaminase activity and indole compound synthesis. Notably, bacterial inoculation under greenhouse conditions showed a positive influence on P. clandestinum growth. We found a significant (p < 0.05) effect on root and shoot length, and shoot dry weight. Shoot length increased by 52% and 30% with 37L and 35P, respectively, compared to those without inoculation treatment. Similarly, the use of 37L and 28P raised shoot dry weight values by 170% and 131%, respectively. In root development, inoculation with strains 37L and E37 increased root length by 134% and 100%, respectively. Beijerinckia sp. 37L was the most effective of the four strains at increasing P. clandestinum biomass and length.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dominique Comeau ◽  
Carole Balthazar ◽  
Amy Novinscak ◽  
Nadia Bouhamdani ◽  
David L. Joly ◽  
...  

Plant growth-promoting rhizobacteria (PGPR) deploy several mechanisms to improve plant health, growth and yield. The aim of this study was to evaluate the efficacy of two Pseudomonas spp. strains and three Bacillus spp. strains used as single treatments and in consortia to improve the yield of Cannabis sativa and characterize the impact of these treatments on the diversity, structure and functions of the rhizosphere microbiome. Herein, we demonstrate a significant C. sativa yield increase up to 70% when inoculated with three different Pseudomonas spp./Bacillus spp. consortia but not with single inoculation treatments. This growth-promoting effect was observed in two different commercial soil substrates commonly used to grow cannabis: Promix and Canna coco. Marker-based genomic analysis highlighted Bacillus spp. as the main modulator of the rhizosphere microbiome diversity and Pseudomonas spp. as being strongly associated with plant growth promotion. We describe an increase abundance of predicted PGPR metabolic pathways linked with growth-promoting interactions in C. sativa.


2018 ◽  
Vol 53 (12) ◽  
pp. 1311-1319
Author(s):  
Fabio Brandi ◽  
Daniel Winter Heck ◽  
Thiago Costa Ferreira ◽  
Wagner Bettiol

Abstract: The objective of this work was to evaluate the commercial formulations of Bacillus subtilis QST-713 and Bacillus pumilus QST-2808 on mycelial growth inhibition of Thielaviopsis paradoxa, for the control of the pineapple disease and growth promotion in sugarcane. The inhibition of mycelial growth was evaluated in paired culture tests. Bacillus isolates were transferred to Petri dishes 48 hours before the pathogen, and the zone of inhibition was determined. The direct effect of the autoclaved commercial formulations at 0, 0.001, 0.01, 0.1, 1.0, and 10.0% on the inhibition of pathogen mycelial growth was evaluated. Bacillus spp. potential in controlling the disease and promoting plant growth was evaluated in assays on plant development and disease severity, both under controlled conditions and in the field. Bacillus isolates inhibited pathogen mycelial growth; however, the isolates did not control the disease effectively in the growth chamber and in the field. In the field assay without infestation by the pathogen, all treatments with biocontrol agents and fungicide increased the yield of cane stalks and sugar per hectare, compared with the control. In the assay with infestation by the pathogen, the B. pumilus-based product (2.0 L ha-1) and fungicide differed from the control only for the variable number of tillers.


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