scholarly journals Effect of some fungicides against the growth inhibition of Sclerotinia sclerotiorum mycelial compatibility groups

2015 ◽  
Vol 55 (4) ◽  
pp. 354-361 ◽  
Author(s):  
Alireza Dalili ◽  
Saeed Bakhtiari ◽  
Hossein Barari ◽  
Majid Aldaghi
Keyword(s):  
Growth Inhibition ◽  
Sclerotinia Sclerotiorum ◽  
Integrated Management ◽  
In Vitro Tests ◽  
Sclerotinia Stem Rot ◽  
Mazandaran Province ◽  
Brassica Napus L ◽  
Northern Iran ◽  
Mycelial Compatibility

Abstract Sclerotinia sclerotiorum (Lib.) de Bary, the causal agent of Sclerotinia stem rot, is one of the most important pathogens of Brassica napus L. in northern Iran. In this study, 13 mycelial compatibility groups (MCGs) of the fungus were identified among 31 isolates sampled from four regions of Mazandaran province, Iran. Effective fungicides are useful in the integrated management of the disease. So, the effect of tebuconazole, propiconazole, cyproconazole, and Rovral-TS at five doses (0.0001, 0.001, 0.01, 0.1, and 1 ppm) was studied on the growth inhibition of S. sclerotiorum as in vitro tests. Maximum inhibition (100%) of S. sclerotiorum mycelial growth was obtained by the highest dose (1 ppm) of all tested fungicides, as well as by the doses of 0.1 and 0.01 ppm of propiconazole, cyproconazole, and tebuconazole. In this investigation, the reaction of S. sclerotiorum isolates belonging to different MCGs was evaluated against tebuconazole, propiconazole, cyproconazole, and Rovral-TS at their EC50 ranges. The results revealed that there was high variation of S. sclerotiorum MCGs against different fungicides. The inhibition percentage varied between 4.29% and 71.72%.

Evaluation of fungicides and bio-control agents in-vitro, against Sclerotinia sclerotiorum causes white stem rot disease in Rapeseed-mustard

2018 ◽  
Vol 3 (02) ◽  
pp. 171-175
Author(s):  
Devesh Pathak ◽  
R. U. Khan
Keyword(s):  
Growth Inhibition ◽  
Sclerotinia Sclerotiorum ◽  
Radial Growth ◽  
Stem Rot ◽  
Yield Losses ◽  
Sclerotinia Stem Rot ◽  
Plant Debris ◽  
Trichoderma Spp ◽  
Rot Disease

Sclerotinia stem rot (SSR) caused by Sclerotinia sclerotiorum (Lib.) de Bary is a major disease of rapeseed-mustard and it is considered next to Alternaria blight in causing yield losses as much as 70 per cent in susceptible crop. The pathogen survives in the form of sclerotia on plant debris or in soil for more than 4 years, which makes it very difficult to manage with conventional approaches. Therefore, its management with fungicides and bio-control agents remains an effective approach. The present study was undertaken in-vitro, using four fungicides viz., vitavax, propiconazole, mancozeb and azoxystrobin at three different concentrations i.e. 0.05%, 0.1% and 0.2% and three species of Trichoderma viz., T. harzianum, T. viride, T. koningii,to find out their relative efficacy in inhibiting mycelial growth of the pathogen. It is evident from the observations that all four fungicides and three Trichoderma spp. resulted a significant effect on growth inhibition of S. sclerotiorum. Among all fungicides tested, vitavax and propiconazole were most effective at all three concentrations (0.05, 0.1 and 0.2 %) and inhibited cent percent radial growth of the pathogen, while mancozeb and azoxystrobin were least effective. Among the bio-control agents, T. viride was noted to be most effective antagonist followed by T. koningii resulting 78.50% and 72.21% growth inhibition, respectively. Whereas, T. harzianum showed minimum radial growth inhibition (49.25%) of S. sclerotiorum in this study.

scholarly journals Carpogenic Germinability of Diverse Sclerotinia sclerotiorum Populations Within the Southwestern Australian Grain Belt

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2891-2897
Author(s):  
Pippa J. Michael ◽  
King Yin Lui ◽  
Linda L. Thomson ◽  
Katia Stefanova ◽  
Sarita J. Bennett
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Temperature Fluctuations ◽  
Sclerotinia Stem Rot ◽  
Dark Cycle ◽  
Diurnal Temperature ◽  
Population Responses ◽  
Carpogenic Germination ◽  
Southwestern Australia ◽  
Temperature Regimes ◽  
Mycelial Compatibility

Sclerotinia stem rot, caused by the necrotrophic plant pathogen Sclerotinia sclerotiorum (Lib.) de Bary, is a major disease of canola and pulses in Australia. Current disease management relies greatly on cultural and chemical means of control. Timing of fungicide applications remains a challenge, because efficacy is dependent on accurate prediction of ascospore release and presence on the plant. The aims of this study were to determine the optimal temperature for carpogenic germination of S. sclerotiorum populations sampled from canola and lupin fields in southwestern Australia and characterize diversity using mycelial compatibility groupings (MCGs). Sclerotia were collected from four diseased canola and one diseased lupin field from across southwestern Australia. Forty sclerotia from each population were incubated at four alternating temperatures of 30/15, 20/15, 20/4, and 15/4°C (12-h/12-h light/dark cycle) and assessed every 2 to 3 days for a 180-day period. MCG groupings for populations were characterized using 12 reference isolates. Results indicated the time to initial carpogenic germination decreased as diurnal temperature fluctuations decreased, with a fluctuation of 5°C (20/15°C) having the most rapid initial germination followed by 11°C (15/4°C) followed by 16°C (20/4°C). Optimal germination temperature for all five populations was 20/15°C; however, population responses to other diurnal temperature regimes varied considerably. No germination was observed at 30/15°C. MCG results indicate extensive diversity within and between populations, with at least 40% of sclerotia within each population unable to be characterized. We suggest that this diversity has enabled S. sclerotiorum populations to adapt to varying environmental conditions within southwestern Australia.

scholarly journals Effects of the Novel Fungicide Benzothiostrobin on Sclerotinia sclerotiorum in the Laboratory and on Sclerotinia Stem Rot in Rape Fields

Plant Disease ◽  
2015 ◽  
Vol 99 (7) ◽  
pp. 969-975 ◽  
Author(s):  
Congying Xu ◽  
Xiaoyu Liang ◽  
Yiping Hou ◽  
Mingguo Zhou
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Pathogenic Fungus ◽  
Field Trials ◽  
Stem Rot ◽  
Cross Resistance ◽  
Synergistic Activity ◽  
The Novel ◽  
Sclerotinia Stem Rot ◽  
Sclerotial Germination

We determined the effects and efficacy of benzothiostrobin, a new strobilurin-derived fungicide, against the plant-pathogenic fungus Sclerotinia sclerotiorum (the causal agent of Sclerotinia stem rot). Mycelial growth and sclerotial germination in vitro were strongly inhibited by benzothiostrobin in the presence of salicylhydroxamic acid. On detached rapeseed leaves, benzothiostrobin at 40 μg/ml reduced lesion development by 87%. No cross-resistance was detected between benzothiostrobin and carbendazim, iprodione, fludioxonil, or boscalid. A formulated mixture of benzothiostrobin and fluazinam at 1:1 had synergistic activity against S. sclerotiorum in vitro. In field trials, benzothiostrobin alone or formulated with fluazinam at 1:1 (150 g a.i. ha−1) was significantly (P < 0.05) superior to iprodione in controlling Sclerotinia stem rot of rapeseed. These results suggest that benzothiostrobin has substantial potential for the control of Sclerotinia stem rot.

scholarly journals Mycelial Compatibility Grouping and Aggressiveness of Sclerotinia sclerotiorum

Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 325-332 ◽  
Author(s):  
L. S. Kull ◽  
W. L. Pedersen ◽  
D. Palmquist ◽  
G. L. Hartman
Keyword(s):  
Population Structure ◽  
Disease Management ◽  
Sclerotinia Sclerotiorum ◽  
Stem Rot ◽  
Management Systems ◽  
Sclerotinia Stem Rot ◽  
Pathogen Population ◽  
Causal Organism ◽  
Soybean Field ◽  
Mycelial Compatibility

Population variability of Sclerotinia sclerotiorum, the causal organism of Sclerotinia stem rot of soybean, was determined by mycelial compatibility grouping (MCG) and isolate aggressiveness comparisons. MCG and aggressiveness of S. sclerotiorum isolates from diverse hosts and geographic locations (Diverse Set, 24 isolates), from a soybean field in Argentina (Argentine Set, 21 isolates), and from soybean fields in DeKalb and Watseka, Illinois (DeKalb Set, 124 isolates, and Watseka Set, 130 isolates) were assessed. Among 299 isolates tested, 42 MCGs were identified, and 61% were represented by single isolates observed at single locations. Within the Diverse Set, 17 MCGs were identified; 1 MCG consisted of six isolates, and 16 MCGs consisted of one isolate each. Nine MCGs were identified within the Argentine field with two MCGs composed of either five or six isolates, two MCGs composed of two isolates, and the remaining composed of one isolate each. Each Illinois field was a mosaic of MCGs, but MCG frequencies differed between the two fields. Common MCGs were identified among the Diverse, DeKalb, and Watseka Sets, but no MCGs within the Argentine Set were observed with other sets. MCG 8 was the most frequently sampled and widely dispersed MCG and occurred at a frequency of 29, 36, and 62% in the Diverse, DeKalb, and Watseka Sets, respectively. Variation in isolate aggressiveness was assessed using a limited-term, plug inoculation technique. Isolate aggressiveness varied (P = 0.001) within the Diverse, Argentine, DeKalb, and Watseka Sets. Within widely dispersed MCGs, isolate aggressiveness varied (P ≤ 0.10); however, within locally observed MCGs detected only in single fields, isolate aggressiveness did not vary. Additionally, individual MCGs within the DeKalb and Watseka Sets differed in isolate aggressiveness. Using six soybean cultivars and six S. sclerotiorum isolates, no cultivar-isolate interaction was detected, but resistant and susceptible cultivars performed similarly when inoculated with either less or highly aggressive isolates. Pathogen population structure and variability in isolate aggressiveness may be important considerations in disease management systems.

scholarly journals Baseline Sensitivity and Control Efficacy of Various Group of Fungicides against Sclerotinia sclerotiorum in Oilseed Rape Cultivation

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1758
Author(s):  
Nazanin Zamani-Noor
Keyword(s):  
Oilseed Rape ◽  
Sclerotinia Sclerotiorum ◽  
Fungicidal Activity ◽  
Management Strategies ◽  
Sclerotinia Stem Rot ◽  
Baseline Sensitivity ◽  
Cultural Management ◽  
Significant Yield ◽  
And Control

Sclerotinia stem rot (SSR), caused by Sclerotinia sclerotiorum, is a devastating disease of oilseed rape that may cause significant yield losses if not controlled by cultural management strategies and fungicide applications. Studies were conducted to evaluate the efficacy of different group of fungicides as well as a biopesticide, including azoxystrobin, boscalid, fludioxonil, prothioconazole, tebuconazole, azoxystrobin/tebuconazole, boscalid/pyraclostrobin, prothioconazole/fluopyram and Bacillus amyloliquefaciens, on baseline sensitivity of S. sclerotiorum isolates under in-vitro conditions as well as control of SSR in the field. Artificial inoculation and mist irrigation prompt to reproducible SSR infection in oilseed rape cultivation. All compounds significantly reduced 36.7% to 86.9% SSR severity and increased 55.2% to 98.7% yield, 1.5% to 7.0% thousand grain-weight, 1.5% to 5.9% oil and 0.1% to 1.3% protein content. Fludioxonil, boscalid/pyraclostrobin and fluopyram/prothioconazole achieved strongest fungicidal activity against SSR. The biopesticide provided 36% of disease control. Under in vitro conditions, B. amyloliquefaciens not only strongly inhibited mycelial growth but also the formation of sclerotia in all concentrations. Boscalid and fludioxonil exhibited the highest level of fungicidal activity against S. sclerotiorum, with mean EC50 values of 1.23 and 1.60 μg a.s. mL−1. The highest variability of EC50 values between isolates was observed towards prothioconazole and azoxystrobin.

scholarly journals Analysis of Differentially Expressed Sclerotinia Sclerotiorum Genes During the Interaction With Moderately Resistant and Highly Susceptible Chickpea Lines

2021 ◽  
Author(s):  
Virginia Mwape ◽  
Fredrick Mobegi ◽  
Roshan Regmi ◽  
Toby Newman ◽  
Lars Kamphuis ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Reduction Process ◽  
Metabolic Process ◽  
Differentially Expressed ◽  
Transcriptional Analysis ◽  
Sclerotinia Stem Rot ◽  
In Planta ◽  
Developmental Factors ◽  
Moderately Resistant

Abstract Background: Sclerotinia sclerotiorum, the cause of Sclerotinia stem rot (SSR), is a host generalist necrotrophic fungus that can cause major yield losses in chickpea (Cicer arietinum) production. This study used RNA sequencing to conduct a timecourse transcriptional analysis of S. sclerotiorum gene expression during chickpea infection. The study explored S. sclerotiorum pathogenicity and developmental factors employed during chickpea infection. Results: During infection of moderately resistant and highly susceptible chickpea lines, 9,491 and 10,487 S. sclerotiorum genes, respectively, were significantly differentially expressed relative to in vitro. Analysis of the upregulated genes revealed enrichment of Gene Ontology biological processes, such as oxidation-reduction process, metabolic process, carbohydrate metabolic process, response to stimulus, and signal transduction. Several gene functional categories were upregulated in planta, including carbohydrate-active enzymes, secondary metabolite biosynthesis clusters, transcription factors and candidate secreted effectors. Differences in S. sclerotiorum genes expressed on varieties with different levels of susceptibility were also observed. Conclusion: These findings provide a framework for a better understanding of S. sclerotiorum interactions with hosts of varying susceptibility levels. Here, we report for the first time on the S. sclerotiorum transcriptome during chickpea infection, which could be important for further studies on this pathogen's molecular biology.

scholarly journals High Genetic Diversity, Phenotypic Uniformity, and Evidence of Outcrossing in Sclerotinia Sclerotiorum in the Columbia Basin of Washington State

2004 ◽  
Vol 94 (7) ◽  
pp. 737-742 ◽  
Author(s):  
Z. K. Atallah ◽  
B. Larget ◽  
X. Chen ◽  
D. A. Johnson
Keyword(s):  
Population Structure ◽  
Sclerotinia Sclerotiorum ◽  
Management Strategies ◽  
Stem Rot ◽  
Columbia Basin ◽  
High Genetic Diversity ◽  
Association Analyses ◽  
Haplotypic Diversity ◽  
Mycelial Compatibility

Sclerotinia sclerotiorum, the causal agent of potato stem rot, is prevalent and poorly managed on potatoes in the Columbia Basin of Washington. Because of the ubiquitous nature of the fungus and high crop diversity within the Columbia Basin, understanding the population structure and the potential for outcrossing of the pathogen would be helpful in developing disease management strategies. The population structure of S. sclerotiorum in the Columbia Basin from potato was examined using microsatellite markers and mycelial compatibility. Analysis of molecular variance revealed that 92% of the variability among 167 isolates was found within subpopulations, with limited, yet statistically significant impact of the collection date, but not the year or location of collection. Linkage disequilibrium and index of association analyses noted a potential for outcrossing in two locations, which was substantiated by the discovery of recombinant ascospores in three field-generated apothecia from the 12 apothecia examined. Microsatellite haplotypes were not correlated with mycelial compatibility groups. This high haplotypic diversity did not seem to impact pathologically important phenotypes. Greenhouse inoculations of potato plants exhibited no significant differences in aggressiveness on potato stems. Moreover, in vitro studies of response to fungicides and temperature stimuli yielded no significant differences among studied isolates. These findings illustrate the potential for outcrossing in warm temperate regions of North America, where a diversity of crops are planted simultaneously and in neighboring fields. This study also indicates that the unsatisfactory management of potato stem rot is likely not directly attributable to genetic factors, but to gaps in agricultural practices.

Seleção e Prospecção de Rizobactérias para o Controle Biológico do Mofo Branco em Espécies de Crotalaria spp

2019 ◽  
Vol 22 (2) ◽  
pp. 90
Author(s):  
Laís Mayara Melo Duré ◽  
Lara Rezek Rochaa ◽  
Ellen Juliete Damasceno Capurro ◽  
Bianca Obês Corrêa
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Fusarium Solani ◽  
Growth Promotion ◽  
Pathogenic Fungi ◽  
In Vitro Tests ◽  
Seed Pathology ◽  
Seed Analysis ◽  
Detached Leaves

O objetivo do trabalho foi isolar micro-organismos de diferentes nichos e avaliar a capacidade dos mesmos no controle de patógenos invitro (Sclerotinia sclerotiorum e Fusarium solani) e in vivo (S. sclerotiorum), além da promoção do crescimento de Crotalaria sp. Asamostras de solo foram pesadas e diluídas para obtenção dos micro-organismos. Nos testes in vitro, as colônias bacterianas, que apresentaram crescimento, foram submetidas ao confrontamento direto com os fungos fitopatogênicos. Para análise fisiológica das sementes de Crotalaria sp, as sementes foram distribuídas em caixas gerbox contendo papel filtro umedecido com água destilada e incubadas a 20-30 ºC por 10 dias. Também foram testadas a antibiose de escleródios em meio líquido. O delineamento usado foi DIC e os dados foram submetidos à análise de variância e comparados por Tukey a 0,5%. Além disso, foi realizada a patologia de sementes tratadas com as bactérias Fit-03 e Fit-04, além da microbiolização das sementes para avaliação da promoção do crescimento em casa de vegetação. Dos 51 isolados, seis foram capazes de produzir substâncias capazes de inibir o crescimento micelial do F. solani e três de S. sclerotiorum. Na avaliação da capacidade de controle de micro-organismos sobre as sementes das duas espécies de Crotalaria sp, Fit-03 e Fit-04 reduziram a incidência de fungos como Aspergillus e Penicillium. Pode-se afirmar que os isolados Fit-03 e Fit-04 apresentam potencial de uso no controle biológico do mofo branco em plantas de Crotalaria sp., bem como amplo espectro de ação.Palavras-chave: Antibiose. Sclerotinia sclerotiorum. Microbiolização de Sementes.AbstractThe objective was to isolate microorganisms of different niches and assess the ability of these in vitro control pathogens (Sclerotinia sclerotiorum and Fusarium solani) and in vivo (S. sclerotiorum) in addition to promoting the growth of Crotalaria sp. Soil samples were weighed and diluted to obtain the microorganisms. In in vitro tests the bacterial colonies that grew were subjected to direct confrontation with the pathogenic fungi. For physiological seed analysis Crotalaria sp. the seeds were distributed in gerbox boxes containing filter paper moistened with distilled water and incubated at 20-30 ° C for 10 days. Antibiosis sclerotia were also tested in liquid medium. The design used was DIC and the data were subjected to analysis of variance and compared by Tukey 0.5%. In addition, there was the seed pathology treated with the Fit-03 bacteria and Fit-04, in addition to microbiolization seeds for evaluation of growth promotion in greenhouse and also spraying the same in detached leaves of C. junceae and C. spectabillis and pathogen inoculation. After 51 isolates, six were able to produce substances capable of inhibiting the mycelial growth of F. solani and three S. sclerotiorum. In the evaluation of microorganisms control capability on the seeds of the two species of Crotalaria sp, Fit-Fit-03 and 04 reduced the incidence of fungi such as Aspergillus and Penicillium. It can be said that the Fit-03 isolated and Fit-04 have potential use in biological control of white mold in plant Crotalaria sp., as well as a broad spectrum of action.Keywords: Antibiosis. Sclerotinia sclerotiorum. Microbiolization seeds.

scholarly journals Population Structure and Aggressiveness of Sclerotinia sclerotiorum From Rapeseed (Brassica napus) in Chongqing City

Plant Disease ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 1201-1206
Author(s):  
Yang Yu ◽  
Junsong Cai ◽  
Linhao Ma ◽  
Zhiqiang Huang ◽  
Yabo Wang ◽  
...  
Keyword(s):  
Population Structure ◽  
Sclerotinia Sclerotiorum ◽  
Plant Pathogens ◽  
Gene Diversity ◽  
Sclerotinia Stem Rot ◽  
Pair Group ◽  
Fungal Plant Pathogens ◽  
Chongqing City ◽  
Mycelial Compatibility ◽  
Rapeseed Production

Sclerotinia sclerotiorum is one of the most devastating fungal plant pathogens of oilseed Brassica and is distributed worldwide. In particular, Sclerotinia stem rot has always been a serious threat to rapeseed production in Chongqing City, China. In this study, simple sequence repeat (SSR) markers and mycelial compatibility groups (MCGs) were used to characterize the population structure of 90 geographic isolates of S. sclerotiorum collected from rapeseed in nine counties of Chongqing. A total of 52 microsatellite haplotypes were identified, and a few haplotypes were found with high frequency. Gene diversity ranged from 0.1570 to 0.4700 in nine populations. A constructed unweighted pair group with arithmetic mean dendrogram based on Nei genetic distance and a STRUCTURE analysis revealed that the genetic composition of the isolates collected in the five counties located in western Chongqing are different from those collected in the two eastern counties, suggesting that breed lines should be cultivated in both the western and eastern regions to effectively evaluate resistance levels. A total of 47 MCGs were identified, and 72% of the MCGs was represented by single isolates. Seven of 13 MCGs that included at least two isolates contained isolates from only one county. SSR haplotypes were not correlated with MCGs. A subset of 34 isolates were inoculated on rapeseed stems, and the aggressiveness showed variation. This research revealed the population genetic structure and aggressiveness of this pathogen in Chongqing, and the results will help to develop disease management and resistance screening strategies.

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