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.

scholarly journals Production of lytic enzymes by Trichoderma strains during in vitro antagonism with Sclerotium rolfsii, the causal agent of stem rot of groundnut

2015 ◽  
Vol 9 (6) ◽  
pp. 365-372 ◽  
Author(s):  
J Parmar H ◽  
P Bodar N ◽  
N Lakhani H ◽  
V Patel S ◽  
V Umrania V ◽  
...  
Keyword(s):  
Sclerotium Rolfsii ◽  
Causal Agent ◽  
Stem Rot ◽  
Lytic Enzymes

scholarly journals SKRINING BAKTERI ANTAGONIS RALSTONIA SP., PENYEBAB PENYAKIT LAYU BAKTERI PISANG DI LAMPUNG

2007 ◽  
Vol 7 (2) ◽  
pp. 100-110
Author(s):  
Titik Nur Aeny ◽  
Radix Suharjo ◽  
Subli Mujim
Keyword(s):  
Bacterial Wilt ◽  
Plant Disease ◽  
Hypersensitive Reaction ◽  
Soil Samples ◽  
Causal Agent ◽  
Antagonistic Bacteria ◽  
Bacterial Identification ◽  
Biochemical Tests ◽  
Colony Color

Screening on Antagonistic Bacteria of Ralstonia sp., the Causal Agent of Banana Bacterial Wilt in Lampung. This study was conducted on May to October 2006. This study was aimed to screen and collect potential bacterial antagonists toward Ralstonia sp., the causal agent of banana bacterial wilt; to identify the collected potential antagonists, and to test the capability of the bacterial antagonist in vitro. A survey to collect soil samples was conducted in 5 districts in Lampung, namely Bandar Lampung, Lampung Selatan, Tanggamus, Lampung Utara, Lampung Tengah, and Lampung Timur. Identification and test of the antagonistic capability was done in the Plant Disease Laboratory, University of Lampung. Identification of the antagonist bacteria was done through several biochemical tests i.e. : gram reaction, hypersensitive reaction on tobacco, oxidative-fermentative, colony color on YDC medium, fluoresence, nitrate reduction, gelatin reduction and starch hydrolise.  The results were then compared to the guidelines of bacterial identification. Twenty one soil samples were collected from those surveyed areas to isolate antagonist bacteria, and 104 isolates were found to be antagonistic to Ralstonia sp.. Based on the biochemical tests, it was showed that 59 isolates were in the group of fluorecent pseudomonad and 45 ones were still unidentified. Out of 104 isolates found, 41 isolates have the ability to inhibit the growth of Ralstonia sp.

scholarly journals Inhibitory Effect of Trichoderma asperellum Isolate against Ralstonia solanacearum Causing Brinjal Wilt

2021 ◽  
Vol 24 (2) ◽  
pp. 107-120
Author(s):  
SMN Islam ◽  
SS Siddique ◽  
MZH Chowdhury ◽  
NJ Mishu
Keyword(s):  
Ralstonia Solanacearum ◽  
Disease Incidence ◽  
Its Region ◽  
Inhibitory Effect ◽  
Dual Culture ◽  
Trichoderma Asperellum ◽  
In Planta ◽  
Quantitative Test ◽  
Trichoderma Isolate

A native Trichoderma isolate was collected from the agricultural soil of Gazipur. This isolate was identified as a Trichoderma asperellum through morphology and analysis of internal transcribed spacer (ITS) region of ribosomal RNA gene sequence and reconstruction of the phylogenetic tree. The antagonistic effects of the newly identified T. asperellum isolate were assessed against brinjal bacterial wilt caused by Ralstonia solanacearum both in vitro and in planta. Both qualitative and quantitative bioassays were conducted in vitro. For qualitative tests, dual culture and antibacterial activity were carried out, and pathogen growth was observed visually. The antagonism of T. asperellum cell free culture filtrate on the growth of R. solanacearum was conducted in a quantitative test. Successful antagonism was recorded after both in vitro qualitative tests. In addition, the lowest colony forming unit was recorded in 100% of CFC (2.4±0.51 ×103 cfu/ml) in quantitative test. The T. asperellum inoculated plant showed low disease incidence (13.33%) when seedlings were challenged with R. solanacearum in planta experiment. Disease incidence was 100% for seedlings when treated with only R. solanacearum. The results showed that the isolated and identified T. asperellum isolate suppressed R. solanacearum growth in vitro and protected the seedling from wilting in planta. Therefore, this isolate could be considered as a potential isolate. Ann. Bangladesh Agric. (2020) 24(2) : 107-120

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 Morphological and Pathogenic Characterization of Sclerotium rolfsii, the Causal Agent of Southern Blight Disease on Common Bean in Uganda

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2130-2137
Author(s):  
Pamela Paparu ◽  
Amos Acur ◽  
Fred Kato ◽  
Catherine Acam ◽  
Justine Nakibuule ◽  
...  
Keyword(s):  
Growth Rate ◽  
Common Bean ◽  
Mycelial Growth ◽  
Smallholder Farmers ◽  
Management Strategies ◽  
Sclerotium Rolfsii ◽  
Southern Blight ◽  
Root Rots ◽  
Mycelial Growth Rate ◽  
Agroecological Zones

Over the last 5 years, Southern blight caused by Sclerotium rolfsii Sacc. has superseded root rots caused by pathogens such as Fusarium and Pythium spp. as a major constraint of common bean (Phaseolus vulgaris L.) production in Uganda. Although S. rolfsii is prevalent in all bean-growing regions of Uganda, there is a lack of information about its diversity and pathogenicity to guide the development of effective management strategies. In total, 348 S. rolfsii isolates were obtained from bean fields in seven agroecological zones of Uganda, with the following objectives: to characterize their morphology, based on mycelial growth rate, mycelium texture, and number of sclerotia; and to determine the pathogenicity of 75 selected isolates on five common bean varieties in artificially inoculated soils in a screenhouse. We found that mycelial growth rate and the number of sclerotia produced on artificial media varied among agroecological zones but not within a zone. The five bean varieties tested were found to be susceptible to S. rolfsii, including varieties MLB49-89A and RWR719 that are resistant to Fusarium and Pythium root rots, respectively. Preemergence damping-off ranged between 0 and 100%, and disease severity index ranged between 4.4 and 100%. The widespread and high levels of S. rolfsii virulence on varieties of common bean indicate that management intervention is urgently required to help reduce losses incurred by Ugandan smallholder farmers. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

scholarly journals Baseline Sensitivity of Pyraclostrobin and Toxicity of SHAM to Sclerotinia sclerotiorum

Plant Disease ◽  
2015 ◽  
Vol 99 (2) ◽  
pp. 267-273 ◽  
Author(s):  
Hong-Jie Liang ◽  
Ya-Li Di ◽  
Jin-Li Li ◽  
Hong You ◽  
Fu-Xing Zhu
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Oxidase Inhibitor ◽  
Cross Resistance ◽  
In Planta ◽  
Baseline Sensitivity ◽  
Vitro Assay ◽  
Quinone Outside Inhibitor

Sclerotinia sclerotiorum is a cosmopolitan plant pathogen notable for its wide host range. The quinone outside inhibitor (QoI) fungicide pyraclostrobin has not been registered for control of S. sclerotiorum in China. In this study, baseline sensitivity of pyraclostrobin was established based on effective concentration for 50% inhibition of mycelial growth (EC50) values of 153 isolates of S. sclerotiorum collected from five provinces of China and toxicity of alternative oxidase inhibitor salicylhydroxamic acid (SHAM) to S. sclerotiorum was determined. Results showed that the frequency distribution of EC50 values of the 153 isolates was unimodal but with a right-hand tail. The mean EC50 value was 0.1027 μg/ml and the range of EC50 values was 0.0124 to 0.6324 μg/ml. Applied as a preventive fungicide in pot experiments, pyraclostrobin at 5, 15, and 45 μg/ml provided control efficacies of 61, 77, and 100%, respectively. There was no positive cross-resistance between pyraclostrobin and carbendazim or dimethachlon. EC50 values for SHAM against four isolates of S. sclerotiorum were 44.4, 51.8, 54.4, and 68.7 μg/ml. SHAM at 20 μg/ml could significantly increase not only the inhibitory effect of pyraclostrobin on mycelial growth on potato dextrose agar media but also the control efficacy in planta. These results indicated that SHAM should not be added into artificial media in in vitro assay of S. sclerotiorum sensitivity to pyraclostrobin. This has broad implications for assay of sensitivity of fungal pathogen to QoI fungicides.

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 Using Plant-Based Preparations to Protect Common Bean against Halo Blight Disease: The Potential of Nettle to Trigger the Immune System

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 63
Author(s):  
Alfonso Gonzalo De la Rubia ◽  
María De Castro ◽  
Inés Medina-Lozano ◽  
Penélope García-Angulo
Keyword(s):  
Common Bean ◽  
Pseudomonas Syringae ◽  
Crop Production ◽  
Inhibitory Effect ◽  
Immune Defense ◽  
Wild Plants ◽  
Halo Blight ◽  
Bean Plants ◽  
Blight Disease

Halo blight disease of beans (Phaseolus vulgaris L.), caused by the bacterium Pseudomonas syringae pv. phaseolicola (Pph), is responsible for severe losses in crop production worldwide. As the current agronomic techniques used are not effective, it is necessary to search for new ones which may prevent disease in common bean. In this study, we challenged four plant-based preparations (PBPs), with no other agronomic uses, as they come from industrial waste (grapevine pomace (RG) and hop residue (RH)) or wild plants (Urtica dioica (U) and Equisetum sp. (E)), to be used as immune defense elicitors against Pph in common bean. After studying their inhibitory effect against Pph growth by bioassays, the two most effective PBPs (RG and U) were applied in common bean plants. By measuring the total H2O2, lipid peroxidation, and antioxidant enzymatic activities, as well as the expression of six defense-related genes—PR1, WRKY33, MAPKK, RIN4, and PAL1, it was observed that U-PBP application involved a signaling redox process and the overexpression of all genes, mostly PR1. First infection trials in vitro suggested that the application of U-PBP involved protection against Pph. The elicitation of bean defense with U-PBP involved a decrease in some yield parameters, but without affecting the final production. All these findings suggest a future use of U-PBP to diminish halo blight disease.

scholarly journals Susceptibility of leguminous green manure species to Rhizoctonia solani and Sclerotium rolfsii

2011 ◽  
Vol 37 (4) ◽  
pp. 218-220 ◽  
Author(s):  
Trazilbo José de Paula Júnior ◽  
Hudson Teixeira ◽  
Rogério Faria Vieira ◽  
Miller da Silva Lehner ◽  
Renan Cardoso de Lima ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Common Bean ◽  
Root Rot ◽  
Green Manure ◽  
Cajanus Cajan ◽  
Seedling Emergence ◽  
Sclerotium Rolfsii ◽  
Southern Blight ◽  
Dolichos Lablab ◽  
Leguminous Crops

We studied the susceptibility of species used as green manure in common bean fields to root rot (Rhizoctonia solani) and southern blight (Sclerotium rolfsii). Seeds of Crotalaria breviflora, Canavalia ensiformis, Cajanus cajan, Dolichos lablab, Stizolobium cinereum, S. aterrimum, and the bean cvs. "Pérola", "Valente" and "Carnaval" were sown in soil infested by either R. solani AG-4 or S. rolfsii in greenhouse. The emergence of D. lablab seedlings in soil infested by R. solani dropped to 62%. C. breviflora, C. ensiformis and cv. "Valente" presented the lowest root rot severity. The pathogen S. rolfsii drastically reduced seedling emergence in all species; no C. cajan and S. cinereum seedling emerged. All plant species presented high southern blight severity. We conclude that leguminous crops are not suitable as green manure for areas of bean cultivation with high R. solani and S. rolfsii populations.

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