Baseline sensitivity and control efficacy of strobilurin fungicide pyraclostrobin against Sclerotium rolfsii

Plant Disease ◽  
2021 ◽  
Author(s):  
Jingmao You ◽  
Tao Tang ◽  
Fanfan Wang ◽  
Ting mao ◽  
Bin Yuan ◽  
...  
Keyword(s):  
Significant Influence ◽  
Sclerotium Rolfsii ◽  
Control Agent ◽  
Cell Membrane Permeability ◽  
Broad Host Range ◽  
Baseline Sensitivity ◽  
Southern Blight ◽  
Oxalate Secretion ◽  
Preventive Efficacy

Sclerotium rolfsii is a fungi pathogen of southern blight with broad host range. The QoI fungicide pyraclostrobin was officially approved for controlling many diseases in 2015. In this study, baseline sensitivity of S.rolfsii to pyraclostrobin was established by measuring the 50% effective concentration (EC50) values of 155 isolates of S.rolfsii. The EC50 ranged from 0.0291 to 1.0871 ug/ml with the mean EC50 values of 0.4469 ± 0.2490 ug/ml (mean ± SD). As preventive fungicide in vitro and field experiment, pyraclostrobin preventive efficacy reached 90% and 80%, respectively, which were much higher than that of control agent carbendazim. Curative efficacy of pyraclostrobin was significantly lower than its preventive efficacy. Pyraclostrobin at 0.1, 0.5, and 2 μg/mL significantly reduced the number of sclerotia produced on potato dextrose agar (PDA) medium, but had no significant influence on their total weight. Pyraclostrobin had no significant influence on mycelial cell membrane permeability, but it significantly reduced oxalate secretion and protein synthesis of S. rolfsii. Our findings are of great significance for resistance monitoring of S. rolfsii and also provide new insight into action mechanism of pyraclostrobin against S. rolfsii.

scholarly journals Southern Blight of Tall Fescue and Bluegrass Caused by Sclerotium rolfsii in Italy

Plant Disease ◽  
2006 ◽  
Vol 90 (2) ◽  
pp. 246-246
Author(s):  
G. Polizzi ◽  
A. Vitale ◽  
I. Castello
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Poa Pratensis ◽  
Sclerotium Rolfsii ◽  
Aerial Mycelium ◽  
Kentucky Bluegrass ◽  
Plant Diseases ◽  
Fluorescent Light ◽  
Southern Blight

Tall fescue (Festuca arundinacea Schreb.) and Kentucky bluegrass (Poa pratensis L.) are the main turfgrass species cultivated in Sicily (southern Italy) for ready lawn (sod) to ornamental purposes. In July 2004 and May 2005, a widespread disease was noticed in two turf nurseries on the eastern side of Sicily on a ready lawn mixture of F. arundinacea cv. Safari (94%) + P. pratensis cv. Cabaret (6%). Numerous yellow, circular- and crescent-shaped patches as much as 30 to 40 cm in diameter were observed. The turf usually died around the perimeter of the patch, but the grass remained green in the center of the ring with a tuft of green grass in the center (frog eye). Affected turf was initially reddish brown and turned brown as it died. Small, round and off-white or tan seed-like structures were dispersed on mycelial strands at the outer edge of the ring in the mat at the base of grasses. The pathogen was identified as Sclerotium rolfsii Sacc. The fungus was isolated directly as aerial mycelium or sclerotia or following surface disinfection (2 min in 0.5% NaOCl) and plating diseased tissues on potato dextrose agar (PDA). Sclerotia were observed in vitro in 7-day-old cultures. Pathogenicity was tested by inoculating two com-mercial ready lawn strips (80 × 100 cm) of two healthy turfgrass species each with three isolates of the fungus. Thirty sclerotia were placed at the base of stems. Noninoculated ready lawn strips served as control. All plants were covered with plastic bags, exposed to diffused daylight for 5 days, and then maintained in a growth chamber at 25 to 28°C under fluorescent light. Disease symptoms and southern blight signs like the ones observed in the field occurred 2 weeks after inoculation. S. rolfsii was reisolated from affected tissues. Symptoms were not detected on any of the non-inoculated ready lawn strips. The disease was serious enough that chemical treatments were required for its control. Southern blight was previously detected on bermudagrass and other cool-season turfgrass genera (1).To our knowledge, this is the first report of southern blight on tall fescue and bluegrass in Italy. Reference: (1) R. W. Smiley. Common Names of Plant Diseases. Diseases of Turfgrasses. Online publication. The American Phytopathological Society, St. Paul, MN.

scholarly journals Inhibitory effect of antagonistic bacteria against Sclerotium rolfsii, causal agent of southern blight of common bean

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Juan Carlos Martínez-Álvarez ◽  
Flavio Camacho-Angulo ◽  
Yolani de Jesús Bojórquez-Armenta ◽  
Bardo Sánchez-Soto ◽  
Jesús Damián Cordero-Ramírez ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Common Bean ◽  
Sclerotium Rolfsii ◽  
Inhibitory Effect ◽  
Causal Agent ◽  
Antagonistic Bacteria ◽  
In Planta ◽  
Southern Blight ◽  
Acinetobacter Pittii

El objetivo del presente estudio fue seleccionar cepas bacterianas de la rizósfera del cultivo de frijol y determinar su potencial para el control de <em>Sclerotium rolfsii</em> bajo condiciones <em>in vitro</em> e <em>in planta</em>. Se recolectaron muestras de suelo en los municipios de Ahome, Guasave y Angostura, Sinaloa, México, durante el ciclo agrícola 2018-2019. Los aislados se evaluaron bajo condiciones <em>in vitro</em> y se seleccionaron los mejores para la evaluación <em>in planta</em> e identificación molecular (tres aislados) con base a la región 16S del ADN ribosomal. Se evaluaron 65 aislados bacterianos <em>in vitro</em> contra <em>S. rolfsii</em> con un porcentaje de inhibición de 2.5 a 65%. <em>Acinetobacter pittii </em>(COHUI06)<em>,</em> <em>Pseudomonas putida</em> (SANMI02) y <em>Burkholderia</em> sp. (GLS06) inhibieron 55, 60 y 65% bajo condiciones <em>in vitro</em>; además resultaron no hemolíticas. Solo <em>Burkholderia</em> sp. ejerció mayor porcentaje de inhibición <em>in planta</em> para el control de <em>S. rolfsii,</em> con reducción de incidencia y severidad de la enfermedad en un 40 y 50% respectivamente, y promovió el peso seco de la planta. Para <em>A. pitti</em> o <em>P. putida</em> no fueron eficientes para el control del hongo <em>in planta</em>. Se sugiere hacer estudios con las bacterias en invernadero y campo.

Null Hyper-Parasitism, a Threat for Successful Biological Control Management

2020 ◽  
Vol 1 (5) ◽  
Author(s):  
S. G. Borkar
Keyword(s):  
Sclerotium Rolfsii ◽  
Control Agent ◽  
The Novel ◽  
Soil Ecosystem ◽  
Control Activity ◽  
Trichoderma Hamatum ◽  
Trichoderma Sp ◽  
Microbial Strain

Null hyper-parasitism, a new term is coined by the author to define the hyper-parasitism by a microbial agent on another hyper-parasite. The novel phenomenon of null hyper-parasitism was discovered in the in vitro and in vivo experimentation, where the bio-control agent Trichoderma hamatum hyper-parasitic on Sclerotium rolfsii, a foot rot pathogen of groundnut, was hyper-parasitiosed by a microbial strain of Aspergillus niger and Bacillus thermophillus. Here A. niger and B. thermophillus as null hyper-parasite nullified the bio-control action of hyper-parasite Trichoderma hamatum on Sclerotium rolfsii. The in vivo experimentation suggest that such type of null hyper-parasitism exist in soil ecosystem, may be to maintain the natural microbial equilibrium and extinction of a microbial species from nature due to presence of hyper-parasite and its antagonistic or bio-control activity as evident in the above case of parasite/pathogen S. rolfsii, its hyper-parasite T. hamatum and null hypersite A. niger and B. Thermophillus. Now, therefore the success of the bio-control or hyper-parasitism of soil borne fungal plant pathogen by Trichoderma sp may be dependent on the non- existence of null hyper-parasite in the soil ecosystem where the hyperparasite has to be used.

scholarly journals Mycelial Compatibility and Pathogenic Diversity Among Sclerotium rolfsii Isolates in the Southern United States

Plant Disease ◽  
2014 ◽  
Vol 98 (12) ◽  
pp. 1685-1694 ◽  
Author(s):  
Chenzhao Xie ◽  
Cheng-Hua Huang ◽  
Gary E. Vallad
Keyword(s):  
United States ◽  
South Carolina ◽  
Sclerotium Rolfsii ◽  
The Other ◽  
Southern United States ◽  
Southern Blight ◽  
Wide Range ◽  
Mycelial Compatibility ◽  
Pathogenic Diversity

Sclerotium rolfsii is a soilborne fungus that causes southern blight on a wide range of plants in tropical and subtropical regions of the world. Eighty-four isolates collected from Florida, Georgia, Louisiana, South Carolina, Texas, and Virginia were paired and assigned to 23 mycelial compatibility groups (MCGs), of which 11 MCGs consisted of a single isolate. Isolates within an MCG typically originated from different hosts and different geographical areas, with the exception of MCG 11. In all, 13 of the 15 isolates in MCG 11 originated from peanut in Georgia and Florida, while the other 2 isolates originated from potato in Virginia and from the ornamental Barlaeria cristata in Florida. Significant differences in the size and number of sclerotia produced in vitro existed between isolates from peanut and other hosts. Nineteen isolates representative of the most common MCGs (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 13, 14, 15, 16, 17, and 18) were tested for pathogenicity on tomato, pepper, and peanut. All isolates were pathogenic on all hosts but virulence differed significantly among isolates. Isolates collected from peanut were the most virulent on all three hosts compared with isolates collected from tomato and pepper. ‘Georgia Green’ peanut was more susceptible to peanut isolates from Georgia than to the other tested isolates. Of the two tomato entries, the commercial tomato ‘Tygress’ was less susceptible than the previously reported resistant breeding line 5635M to many of the S. rolfsii isolates tested, with the exception of the peanut isolates collected from Georgia. These initial findings suggest that considerable variation exists among S. rolfsii isolates throughout the southern United States, with some indications of specialization for the isolates collected from peanut.

scholarly journals Uji Antagonisme Bacillus cereus terhadap Rhizoctonia solani dan Sclerotium rolfsii

2016 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Nurul Hidayah ◽  
Titiek Yulianti
Keyword(s):  
Biological Control ◽  
Growth Rate ◽  
Rhizoctonia Solani ◽  
Biological Control Agent ◽  
Sclerotium Rolfsii ◽  
Control Agent ◽  
Dual Culture ◽  
Bacillus Sp ◽  
Unfavorable Condition

<p>Jamur Rhizoctonia solani dan Sclerotium rolfsii merupakan kelompok jamur steril (tidak menghasilkan spora) tetapi dapat menghasilkan sklerosia sebagai sumber inokulum primer, dan struktur istirahat jamur yang dapat bertahan selama beberapa tahun di dalam tanah saat kondisi lingkungan kurang menguntungkan. Penggunaan fungisida, fumigasi, dan solarisasi tanah telah digunakan untuk mengendalikan kedua jamur tersebut, namun hasil yang diperoleh masih beragam. Pengendalian hayati dengan menggunakan bakteri Bacillus sp. yang merupakan salah satu kelompok agens hayati patogen diketahui memberikan hasil yang baik pada beberapa tanaman. Penelitian yang bertujuan menguji potensi B. cereus dalam menghambat pertumbuhan jamur R. solani dan S. rolfsii secara in vitro dilaksanakan di Laboratorium Fitopatologi Balittas dengan menggunakan metode dual culture pada media potato dextrose agar (PDA). Miselia jamur R. solani dan S. rolfsii masing-masing berumur 5 hari diambil dengan menggunakan cork borer ukuran 0,5 cm ditanam pada media PDA berhadapan dengan B. cereus dengan jarak 3 cm. Penelitian disusun dalam rancangan acak lengkap dan diulang empat kali. Pengamatan dilakukan terhadap persentase penghambatan pertumbuhan jamur oleh Bacillus sp. dan laju pertumbuhan jamur. Hasil penelitian menunjukkan bahwa Bacillus sp. mampu menghambat pertumbuhan miselia R. solani dan S. rolfsii masing-masing sebesar 68,9% dan 33% pada hari ketiga setelah perlakuan. Keberadaan B. cereus dapat memperlambat laju pertumbuhan R. solani (15,5 mm/24 jam), dibandingkan perlakuan kontrol (tanpa B. cereus) sebesar 19,7 mm/24 jam. Hasil ini menunjukkan bahwa B. cereus dapat menghambat pertumbuhan R. solani dan berpotensi untuk dikembangkan sebagai agens hayati.</p><p> </p><p>Rhizoctonia solani and Sclerotium rolfsii (the causal agents of damping off disease on various hosts) are the group of sterile fungi that cannot produce spores. Nevertheless, they produce sclerotia as primary inocula and resting spores when facing unfavorable condition. Several control methods using chemical fungicides and solarization had been conducted, but the results were still inconsistent. In addition, the use of Bacillus sp. as a biological control agent for several plant diseases had provided successful results. Furthermore, the research aimed to evaluate the potency of B. cereus towards R. solani and S. rolfsii in vitro was carried out in the laboratory of phytopathology using dual culture method on PDA medium. Five days of R. solani and S. rolfsii miselia were plugged and inoculated on PDA medium toward B. cereus. The research was arranged by completely randomized design with four replicates. The percentage of fungal inhibition and fungal growth rate were observed. The result showed that B. cereus exhibited mycelial growth inhibition activity of R. solani and S. rolfsii by 68,9% and 33% three days after treatments, respectively. The result also indicated that<br />B. cereus has a potential prospect to be developed as a biological control agent because the bacteria could suspend the growth rate of R. solani.</p>

scholarly journals Advent of Trichoderma as a bio-control agent- A review

2016 ◽  
Vol 8 (2) ◽  
pp. 1100-1109 ◽  
Author(s):  
Anita Puyam
Keyword(s):  
Disease Management ◽  
Fusarium Oxysporum ◽  
Fungal Pathogens ◽  
Crop Improvement ◽  
Trichoderma Viride ◽  
Sclerotium Rolfsii ◽  
Control Agent ◽  
Toxic Substances ◽  
Trichoderma Spp

Trichoderma spp are free living filamentous fungi. They are cosmopolitan and versatile in nature. They have the potential to produce several enzymes that can degrade the cell wall materials. Also, they release a number of fungi toxic substances that can inhibit the growth of the fungal pathogens. Many mechanisms have been described on how Trichoderma exert beneficial effects on plants as a bio-control agent. But due to its versatile nature, its potential cannot be explored to its full extent. And it is a developing science in the field of bio-control with its new discoveries adding to the usefulness of the fungi as a bio-control agent. Its development as a bio-control agent passes through many phases and each phase adding novel ideas that will help in the development of an efficient bio-agent which in turn will help in the crop improvement and disease management. The studies on their various aspects responsible for bio-control will open a flood gate to the development of Trichoderma as an efficient and reliable bio-agent and provide a better scope for implementation in crop and disease management. The in vitro antagonistic activity of Trichoderma viride against phytopathogens (Sclerotium rolfsii, Fusarium oxysporum f.s.p. ciceri, Fusarium oxysporum f.s.p. udum) was studied and it was found to be potentially effective against F. oxysporum f.s.p. ciceri followed by F. oxysporum f.s.p. udum and Sclerotium rolfsii.

scholarly journals PERAN AGEN HAYATI ASAL RIZOSFER DAN ENDOFIT MENEKAN PENYAKIT BUSUK SKLEROTIUM ROLFSII BAWANG DAUN DI MEDIA GAMBUT (Role of Rhizosphere and Endophytes Biological Agents to Supress Sclerotium rolfsii Rot Disease on Scallions in the Peat Media)

AgriPeat ◽  
2019 ◽  
Vol 19 (02) ◽  
pp. 68-76
Author(s):  
Admin Journal
Keyword(s):  
Biological Control Agent ◽  
Peat Soil ◽  
Sclerotium Rolfsii ◽  
Control Agent ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
In Planta ◽  
Antagonistic Fungi ◽  
Rot Disease

ABSTRACTThe Sclerotium Rot Disease is highly destructive to the scallions cultivation in the peat soil. Theantagonistic fungi isolated from the rhizosphere and the endophytes of healthy plants, have beenproven to be able to reduce Sclerotium rolfsii. The aim of this study was to evaluate thecharacteristics of antagonistic fungi from rhizosphere and endophytes of Scallions to S. rolfsii in- vitro in the laboratory. The purpose of this study was also to perform the suppression test on theintensity of Sclerotium rolfsiiRot Disease in planta in the peat media in the screen house. Thisresearch it was shown that genus Fusarium, Penicillium, Aspergillusas antagonistic fungi, wereidentified from the endophytes, meanwhile genus Trichoderma, Penicillium dan Aspergillus sp. were identified from the rhizosphere. Trichoderma Rz-1 and Trichoderma Rz-3 isolated from therhizosphere was shown to have the highest antagonistic activity by 94,4 %, followed by AspergillusEd-2, which was isolated from the endophytes by 83,8%. In planta on peat media, TrichodermaRz-1 was capable to demonstrate 82,19% of antagonistic effect and it could suppress SclerotiumRot Diseasehence it produced the fresh weight of the plant highest to 19gcluster-1. Taken together,the result of this study showed that Trichoderma Rz-1 isolated from rhizosphere has been proven tobe the most beneficial to reduce the Sclerotium rolfsii on Scallions as a biological control agent,especially in peat soils.Keywords: biocontrol, rhizosphere,endophyte, scallions, Sclerotium rolfsii

scholarly journals Efficacy of Trichoderma against Sclerotium rolfsii causing collar rot disease of lentil under in vitro conditions

2018 ◽  
Vol 10 (1) ◽  
pp. 307-312
Author(s):  
Shiva Kant Kushwaha ◽  
Sanjeev Kumar ◽  
Balkishan Chaudhary
Keyword(s):  
Culture Filtrate ◽  
Field Condition ◽  
Radial Growth ◽  
Mycelial Growth ◽  
Trichoderma Viride ◽  
Sclerotium Rolfsii ◽  
Control Agent ◽  
Collar Rot ◽  
Rot Disease

Three biocontrol agents viz., Trichoderma viride, T. virens and T. harzianum were evaluated to test the antagonism against Sclerotium rolfsii under in vitro conditions. All the three antagonists’ viz., T. viride, T. virens and T. harzianum have shown the potential of parasitizing the growth of Sclerotium rolfsii in vitro. The rate of inhibition was fastest in T. harzianum (63.60%) followed by T virens (51.5 %). Least inhibition was recorded in T. viride (50.85% ) after 72 hours of incubation. However, T. viride showed the highest (91.31%) reduction in sclerotia formation followed by T. harzianum (84.92%) and T. virens (84.29%) after 15 days of incubation. The volatile compounds from Trichoderma viride were found most effective in suppressing the mycelial growth (51.11%) and sclerotia production (95.90%) of the target pathogen. The culture filtrate from both T. harzianum and T. viride (15% concentration) was found very effective in inhibiting the radial growth (57.46 and 49.62%) and sclerotia formation (98.20 and 99.83%) of Sclerotium rolfsii. The antagonists such as T. harzianum and T. viride can be used as a bio-control agent against S. rolfsii under field condition.

scholarly journals Use of non-chemical methods for the management of southern blight disease of carrot incited by Sclerotium rolfsii

2020 ◽  
Vol 1 (2) ◽  
pp. 74-85
Author(s):  
M. Tanbir Rubayet ◽  
Farhana Prodhan ◽  
M. Shamim Hossain ◽  
Minhaz Ahmed ◽  
M. Abdullah Al Mamun ◽  
...  
Keyword(s):  
Radial Growth ◽  
Sclerotium Rolfsii ◽  
Field Trials ◽  
Soil Solarization ◽  
Leaf Extracts ◽  
Southern Blight ◽  
Blight Disease ◽  
Th 1

This experiment was conducted to assess the effect of Trichoderma harzianum, soil solarization, and biofumigant on southern blight dis-ease of carrot incited by Sclerotium rolfsii isolate CS 5. A series of in-vitro and in-vivo trials laid out to select a virulent isolate of S. rolfsii against the carrot variety New Kuroda and evaluated the mustard, cabbage, cauliflower, and broccoli leaf extracts for choosing an effec-tive biofumigant against test pathogen. Mustard was the most effec-tive in inhibiting the radial growth, and sclerotia formation (80.37 and 83.37%) of S. rolfsii (isolate CS 5) at 40% level of concentration followed by cabbage leaf extract (62.22 and 68.69%). On the contrary, a total of 10 isolates of T. harzianum were screened against the test pathogen on Potato Dextrose Agar (PDA) medium for choosing a dominant isolate of T. harzianum. The isolate Th-6 was found as the most active in inhibiting the radial growth (84.44%) of S. rolfsii fol-lowed by Th-1 (75.56%). In the application of T. harzianum, biofumi-gation, and soil solarization, the treatment appeared to be the most superior in reducing pre- and post-emergence mortality of carrot during secondary field trials. The lowest southern blight disease inci-dence (10.77%), and disease severity (12.78%) were found at the same treatment. Subsequently, the yield of carrot was increased 155.18% which might be due to the reduction of carrot disease as well as the addition of organic materials in the soil.

scholarly journals In Vitro Antagonism between Phytopathogenic Fungi Sclerotium rolfsii and Trichoderma Strains

2015 ◽  
Vol 3 (1) ◽  
pp. 16-19 ◽  
Author(s):  
H. J. Parmar ◽  
Mohamed M. Hassan ◽  
N. P. Bodar ◽  
V. V. Umrania ◽  
S.V. Patel ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Trichoderma Viride ◽  
Sclerotium Rolfsii ◽  
Pathogenic Fungi ◽  
Control Agent ◽  
Phytopathogenic Fungi ◽  
Stem Rot ◽  
New Delhi ◽  
Rot Disease

Six Trichoderma strains (collected from IARI, New Delhi and MTCC, Chandigarh) were tested for their ability to inhibit soil born pathogenof groundnut mainly Sclerotium rolfsii (causing stem rot on groundnut). Morphological observations of Trichoderma strains as well asphytopathogenic fungi S. rolfsii were made from culture grown at 28 0C for about one week on PDA media. The radial growth, fastest growthand coiling of test fungus of various Trichoderma strains on plant pathogenic fungi S. rolfsii were examined under LEICA phase contrastbinocular light microscope. In vitro percent growth inhibition of S.rolfsii by various Trichoderma strain was recorded at 5 days after inoculationat 28 oC in the 90 cm petriplates. Results obtained from the antagonism study indicated that Trichoderma viride (NBAII Tv 23) inhibited 61%growth of phytopathogenic fungi S. rolfsii followed by T. harzianum (NBAII Th1) (55% growth inhibition of pathogen). This suggested thatamong different Trichoderma strains, T. viride was the best bio-control agent to inhibit in vitro growth of phytopathogen S.rolfsii whichotherwise cause stem rot disease in groundnut.DOI: http://dx.doi.org/10.3126/ijasbt.v3i1.11845  Int J Appl Sci Biotechnol, Vol. 3(1): 16-19      

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