scholarly journals Biological control of banana black Sigatoka disease with Trichoderma

2015 ◽  
Vol 45 (6) ◽  
pp. 951-957 ◽  
Author(s):  
Poholl Adan Sagratzki Cavero ◽  
Rogério Eiji Hanada ◽  
Luadir Gasparotto ◽  
Rosalee Albuquerque Coelho Neto ◽  
Jorge Teodoro de Souza
Keyword(s):  
Field Experiments ◽  
Biocontrol Agent ◽  
Its Region ◽  
Trichoderma Atroviride ◽  
Black Sigatoka ◽  
Trichoderma Spp ◽  
Fungicide Sensitivity ◽  
Sensitivity Tests ◽  
Black Sigatoka Disease ◽  
Reduce Disease Severity

Black Sigatoka disease caused by Mycosphaerella fijiensis is the most severe banana disease worldwide. The pathogen is in an invasive phase in Brazil and is already present in most States of the country. The potential of 29 isolates of Trichoderma spp. was studied for the control of black Sigatoka disease under field conditions. Four isolates were able to significantly reduce disease severity and were further tested in a second field experiment. Isolate 2.047 showed the best results in both field experiments and was selected for fungicide sensitivity tests and mass production. This isolate was identified as Trichoderma atroviride by sequencing fragments of the ITS region of the rDNA and tef-1α of the RNA polymerase. Trichoderma atroviride was as effective as the fungicide Azoxystrobin, which is recommended for controlling black Sigatoka. This biocontrol agent has potential to control the disease and may be scaled-up for field applications on rice-based solid fermentation

scholarly journals Molecular Characterization of Trichoderma spp. Isolates by Internal Transcribed Spacer (ITS) Region Sequencing Technique and its Use as a Biocontrol Agent

2020 ◽  
Vol 14 (1) ◽  
pp. 70-77
Author(s):  
Ziyaul Haque ◽  
Mohammed S. Iqbal ◽  
Ausaf Ahmad ◽  
Mohd S. Khan ◽  
Jyoti Prakash
Keyword(s):  
Internal Transcribed Spacer ◽  
Biocontrol Agent ◽  
Its Region ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Dual Culture ◽  
Sequencing Analysis ◽  
Trichoderma Spp ◽  
Sequencing Technique ◽  
Its Region Sequencing

Objective: In the present investigation, Trichoderma spp., isolated from rhizospheric soil, has been identified by Internal Transcribed Spacer (ITS) region sequencing technique and its antagonistic activity was evaluated against A. niger. Methods: The sequencing analysis was done with its ITS1 region of the rRNA gene. Using the ITS1 amplified products for all isolated fungi, a bi-directional DNA sequencing was done with high quality bases (>98% - 100%). Antagonistic activity was done using dual culture technique. Results: All of the ITS1 nucleotide sequences obtained in this study matched 97% - 100% with the published sequence of Trichoderma spp. The results confirmed the strains as T. asperellum and T. viride with gene bank accession no. (ZTa); MK937669 and (ZTv); MK503705, respectively. When phylogenetic analysis was done for the isolates, the optimal tree with the sum of branch length = 0.69585023 and 0.10077756 for T. asperellum and T. viride, respectively, was observed. There were a total of 678 and 767 for T. asperellum and T. viride positions in the final dataset, respectively. Antagonistic activity was done for the isolated strains of Trichoderma spp. against A. niger, and it was found that T. asperellum showed maximum antagonistic activity (79.33±7.09%). Conclusion: The findings prolong the genome availability for relative investigations pointing out phenotypic variances to compare with Trichoderma genetic diversity. The present investigation delivered the Bases of future studies for better knowledge in understanding the complicated connections of Trichoderma spp. to be used as an effective biocontrol agent.

scholarly journals Endophytic colonisation of perennial ryegrass by Trichoderma atroviride

2015 ◽  
Vol 68 ◽  
pp. 444-444
Author(s):  
A. Daryaei ◽  
R.E. Falloon ◽  
E.E. Jones ◽  
D.R.W. Kandula ◽  
H. Ghazalibiglar ◽  
...  
Keyword(s):  
Plant Growth ◽  
Perennial Ryegrass ◽  
Field Experiments ◽  
Trichoderma Atroviride ◽  
Growth Promoters ◽  
Trichoderma Spp ◽  
Beneficial Effects ◽  
Reproductive Structures ◽  
Plant Growth Promoters

Trichoderma spp are widely used as biocontrol agents and plant growth promoters Endophytic colonisation of perennial ryegrass (Lolium perenne) by T atroviride strains was studied in laboratory greenhouse and field experiments Four strains of T atroviride were inoculated into in vitro agar cultures or potting mix with ryegrass seeds for colonisation studies The strains were also produced as prill or granule formulations for application in the field experiment Microscopy was used to observe fungal structures in plant tissue segments from pot or fieldgrown plants Segments were also surface sterilised and placed onto Trichoderma selective media Fungal colonies recovered were verified as T atroviride by sequencing the tef1 gene No endophytic colonisation occurred in any noninoculated plants and no Trichoderma endophytic colonisation was observed in fieldgrown plants However microscopy revealed fungal hyphae and reproductive structures characteristic of Trichoderma in root and stem sheath tissues of inoculated plants from in vitro cultures and pots These results were verified by sequencing the tef1 gene This study has demonstrated endophytic colonisation of ryegrass by T atroviride strains which may be related to beneficial effects on plant growth and disease control

scholarly journals Synergistic Effect of Combined Application of a New Fungicide Fluopimomide with a Biocontrol Agent Bacillus methylotrophicus TA-1 for Management of Gray Mold in Tomato

Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1991-1997 ◽  
Author(s):  
Xiaoxue Ji ◽  
Jingjing Li ◽  
Zhen Meng ◽  
Shouan Zhang ◽  
Bei Dong ◽  
...  
Keyword(s):  
Field Experiments ◽  
Biocontrol Agent ◽  
Severe Disease ◽  
Combined Treatment ◽  
Field Trials ◽  
Antimicrobial Activities ◽  
Gray Mold ◽  
Control Efficacy ◽  
Bacillus Methylotrophicus

Gray mold caused by Botrytis cinerea can be a severe disease of tomato infecting leaves and fruits of tomato plants. Chemical control is currently the most effective and reliable method; however, application of fungicides has many drawbacks. The combination of biological control agents with newly developed fungicides may be a practicable method to control B. cinerea. Fluopimomide is a newly developed fungicide with a novel mode of action. Bacillus methylotrophicus TA-1, isolated from rhizosphere soil of tomato, is a bacterial strain with a broad spectrum of antimicrobial activities. Little information is currently available about the effect of fluopimomide and its integrated effect on B. cinerea. Therefore, laboratory, pot, and field experiments were carried out to determine the effects of fluopimomide alone and in combination with B. methylotrophicus TA-1 against gray mold on tomato. The in vitro growth of B. methylotrophicus TA-1 was unaffected by 100 mg liter−1 fluopimomide. Inhibition of B. cinerea mycelial growth was significantly increased under combined treatment of fluopimomide and B. methylotrophicus TA-1. In greenhouse experiments, efficacy against gray mold was significantly greater by an integration of fluopimomide and B. methylotrophicus TA-1 than by either alone; control efficacy of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 at 108 colony-forming units (cfu) ml−1 reached 70.16 and 69.32%, respectively, compared with the untreated control. In both field trials during 2017 and 2018, control efficacy was significantly higher for the combination of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 than for either treatment alone. The results from this study indicated that integration of the new fungicide fluopimomide with the biocontrol agent B. methylotrophicus TA-1 synergistically increased control efficacy of the fungicide against gray mold of tomato.

Light-induced conidiation ofTrichodermaspp. strains is accompanied by development-dependent changes in the Ca2+binding to cell walls

2018 ◽  
Vol 64 (11) ◽  
pp. 856-864 ◽  
Author(s):  
Szilvia Kontár ◽  
L’udovít Varečka ◽  
Michal Híreš ◽  
Svetlana Kryštofová ◽  
Martin Šimkovič
Keyword(s):  
Fluorescence Microscopy ◽  
Cell Walls ◽  
Binding Capacity ◽  
Trichoderma Atroviride ◽  
Major Fraction ◽  
Trichoderma Spp ◽  
Intracellular Compartments ◽  
Effect Of Light

The effect of light on the binding of Ca2+to mycelia and to cell walls isolated from aerial mycelia of three strains of Trichoderma spp. was studied. Two independent methods were used to measure the total Ca2+content in mycelia and the Ca2+bound to cell walls isolated from aerial mycelia. The results of these methods showed that the light-induced formation and maturation of conidia in Trichoderma spp. is accompanied by increased Ca2+deposition in mycelia and cell walls. Moreover, the cultivation of Trichoderma atroviride F-534 in the presence of45Ca2+under circadian illumination showed that radioactivity was exclusively localized in the light-induced conidial rings of aerial mycelia. The fluorescence microscopy of chlortetracycline-stained mycelia showed that the major fraction of Ca2+was accumulated in conidia and fructification structures, or some intracellular compartments in T. atroviride F-534 grown under circadian illumination, while only a limited amount of Ca2+was associated with hyphal surfaces. In addition, the study of45Ca2+binding to cell walls revealed that T. atroviride F-534 displays both increased45Ca2+binding capacity and elevated affinity to45Ca2+binding upon illumination. The results indicate that conidia formation and (or) maturation is associated with changes in Ca2+homeostasis.

Effective control of black Sigatoka disease using a microbial fungicide based on Bacillus subtilis EA-CB0015 culture

2015 ◽  
Vol 87 ◽  
pp. 39-46 ◽  
Author(s):  
Jaime A. Gutierrez-Monsalve ◽  
Sandra Mosquera ◽  
Lina María González-Jaramillo ◽  
John J. Mira ◽  
Valeska Villegas-Escobar
Keyword(s):  
Bacillus Subtilis ◽  
Effective Control ◽  
Black Sigatoka ◽  
Black Sigatoka Disease

scholarly journals Phylogenetic Analysis of Downy Mildew Pathogens of Opium Poppy and PCR-Based In Planta and Seed Detection of Peronospora arborescens

2007 ◽  
Vol 97 (11) ◽  
pp. 1380-1390 ◽  
Author(s):  
Blanca B. Landa ◽  
Miguel Montes-Borrego ◽  
Francisco J. Muñoz-Ledesma ◽  
Rafael M. Jiménez-Díaz
Keyword(s):  
Downy Mildew ◽  
Field Experiments ◽  
Phylogenetic Analyses ◽  
Its Region ◽  
Epidemiological Studies ◽  
Papaver Somniferum ◽  
Opium Poppy ◽  
Recent Common Ancestor ◽  
In Planta ◽  
Commercial Seed

Severe downy mildew diseases of opium poppy (Papaver somniferum) can be caused by Peronospora arborescens and P. cristata, but differentiating between the two pathogens is difficult because they share morphological features and a similar host range. In Spain, where severe epidemics of downy mildew of opium poppy have occurred recently, the pathogen was identified as P. arborescens on the basis of morphological traits. In this current study, sequence homology and phylogenetic analyses of the internal transcribed spacer regions (ITS) of the ribosomal DNA (rDNA) were carried out with DNA from P. arborescens and P. cristata from diverse geographic origins, which suggested that only P. arborescens occurs in cultivated Papaver somniferum in Spain. Moreover, analyses of the rDNA ITS region from 27 samples of downy-mildew-affected tissues from all opium-poppy-growing regions in Spain showed that genetic diversity exists within P. arborescens populations in Spain and that these are phylogenetically distinct from P. cristata. P. cristata instead shares a more recent, common ancestor with a range of Peronospora species that includes those found on host plants that are not members of the Papaveraceae. Species-specific primers and a PCR assay protocol were developed that differentiated P. arborescens and P. cristata and proved useful for the detection of P. arborescens in symptomatic and asymptomatic opium poppy plant parts. Use of these primers demonstrated that P. arborescens can be transmitted in seeds and that commercial seed stocks collected from crops with high incidence of the disease were frequently infected. Field experiments conducted in microplots free from P. arborescens using seed stocks harvested from infected capsules further demonstrated that transmission from seedborne P. arborescens to opium poppy plants can occur. Therefore, the specific-PCR detection protocol developed in this study can be of use for epidemiological studies and diagnosing the pathogen in commercial seed stocks; thus facilitating the sanitary control of the disease and avoidance of the pathogen distribution in seeds.

Fijiensin, the first phytotoxin fromMycosphaerella fijiensis, the causative agent of Black Sigatoka disease

1990 ◽  
Vol 46 (9) ◽  
pp. 982-984 ◽  
Author(s):  
R. K. Upadhyay ◽  
G. A. Strobel ◽  
S. J. Coval ◽  
J. Clardy
Keyword(s):  
Causative Agent ◽  
Black Sigatoka ◽  
Black Sigatoka Disease

scholarly journals First Draft Genome Sequence Resource of a Strain of Pseudocercospora fijiensis Isolated in North America

2020 ◽  
Vol 110 (10) ◽  
pp. 1620-1622
Author(s):  
Luis Amarillas ◽  
Mitzi Estrada-Acosta ◽  
Rubén G. León-Chan ◽  
Carlos López-Orona ◽  
Luis Lightbourn
Keyword(s):  
North America ◽  
Fungicide Resistance ◽  
Fungal Pathogens ◽  
Genomic Sequence ◽  
Draft Genome ◽  
Bioinformatic Analysis ◽  
Black Sigatoka ◽  
Efficient Management ◽  
Black Sigatoka Disease ◽  
Pseudocercospora Fijiensis

Black Sigatoka disease, caused by the fungus Pseudocercospora fijiensis, is one of the most devastating diseases of banana around the world. Fungicide applications are the primary tool used to manage black Sigatoka, but fungicide resistance in P. fijiensis, as in other fungal pathogens, is one of the major limitations in the efficient management and prevention of this disease. In the current study, we present the draft genome of P. fijiensis strain IIL-20, the first genomic sequence published from a strain of this fungus isolated in North America. Bioinformatic analysis showed putative genes involved in fungus virulence and fungicide resistance. These findings may lead us to a better understanding of the molecular pathogenesis of this fungal pathogen and also to the discovery of the mechanisms conferring fungicide resistance.

scholarly journals Relationship Between Fungicide Sensitivity and Control of Gummy Stem Blight of Watermelon Under Field Conditions

Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1780-1784 ◽  
Author(s):  
A. Thomas ◽  
D. B. Langston ◽  
H. F. Sanders ◽  
K. L. Stevenson
Keyword(s):  
Fungicide Resistance ◽  
Field Experiments ◽  
In Vitro Assays ◽  
Didymella Bryoniae ◽  
Fungicide Sensitivity ◽  
Thiophanate Methyl ◽  
Stem Blight ◽  
Gummy Stem Blight ◽  
And Control

Gummy stem blight (GSB), caused by the fungus Didymella bryoniae, is the most destructive disease of watermelon and is managed primarily with fungicides. D. bryoniae has developed resistance to many fungicides that were once very effective, including azoxystrobin, boscalid, and thiophanate-methyl. Field experiments were conducted in Tifton (TN) and Reidsville (RV), GA in 2009 and 2010 to establish a relationship between frequency of resistance to a fungicide based on in vitro assays and its efficacy in the management of GSB. Frequency of resistance to boscalid, thiophanate-methyl, and azoxystrobin was >0.80 in isolates collected from nontreated plots in both locations and years. All isolates collected after six applications of boscalid, thiophanate-methyl, or azoxystrobin were resistant to the respective fungicide. All isolates collected from treated and nontreated plots were sensitive to tebuconazole and difenoconazole. GSB severity was assessed on a weekly basis from 63 days after planting. GSB severity in plots treated with boscalid, thiophanate-methyl, or azoxystrobin was not significantly different from that in the nontreated plots (39%, TN-2009; 45%, TN-2010; and 16%, RV-2010). GSB severity in tebuconazole-treated plots (27%, TN-2009; 14%, TN-2010; and 4%, RV-2010) was significantly lower than all other treatments and the nontreated control. There was a consistent negative association between frequency of fungicide resistance and disease control in the field. Thus, knowledge of the frequency of fungicide resistance in the pathogen population will be helpful in selecting the most effective fungicides for the management of GSB in watermelon fields.

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