Characterization of Prochloraz Resistance in Fusarium fujikuroi from the Heilongjiang Province in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Qin Peng ◽  
Waqas Younas Muhammad ◽  
Jikun Yang ◽  
Hongwei Zhu ◽  
Jianqiang Miao ◽  
...  
Keyword(s):  
Severity Index ◽  
Field Resistance ◽  
Cross Resistance ◽  
Fusarium Fujikuroi ◽  
Heilongjiang Province ◽  
Bakanae Disease ◽  
Resistance Risk ◽  
Significant Difference ◽  
Resistant Strains

Prochloraz is widely used to control the rice bakanae disease caused by Fusarium fujikuroi. The current study was aimed at monitoring the development of F. fujikuroi resistance to prochloraz in the Heilongjiang province, and at analyzing the fitness of F. fujikuroi strains with different resistance levels. The results indicated that the majority of the 89 F. fujikuroi strains collected from the Heilongjiang province were resistant to prochloraz, with resistance frequency reaching 92.1%. To assess the field resistance risk of prochloraz, 21 F. fujikuroi strains with different resistance levels were selected to investigate their biological characteristics and assess their fitness. Mycelial growth, sporulation, and germination rates were significantly different among the tested strains. However, when grouped into two sub-populations, no significant difference was tested between prochloraz-resistant and prochloraz-sensitive strains. Pathogenicity assays revealed that the disease severity index of prochloraz-resistant strains was higher than that of prochloraz-sensitive strains. Cross-resistance assays showed no cross-resistance between prochloraz and five other fungicides, namely phenamacril, ipconazole, tebuconazole, carbendazim, and fluopyram. Ffcyp51A gene overexpression was observed in the prochloraz-resistant F. fujikuroi strains, following exposure to prochloraz. Collectively, these results indicated that F. fujikuroi resistance against prochloraz was severe. Furthormore, prochloraz-resistant strains were highly fit and could potentially become a dominant population in rice fields, consequently resulting in yield loss.

Activity of A Novel Succinate Dehydrogenase Inhibitor Fungicide Pydiflumetofen against Fusarium fujikuroi causing Rice Bakanae Disease

Plant Disease ◽  
2021 ◽  
Author(s):  
Yang Bai ◽  
Chun-Yan Gu ◽  
Rui Pan ◽  
Muhammad Abid ◽  
Hao-Yu Zang ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Succinate Dehydrogenase ◽  
Field Trials ◽  
Cell Membrane Permeability ◽  
Cross Resistance ◽  
Fusarium Fujikuroi ◽  
Control Efficacy ◽  
Bakanae Disease ◽  
Geographical Regions ◽  
Succinate Dehydrogenase Inhibitor

New fungicides are tools to manage fungal diseases and overcome emerging resistance in fugnal pathogens. In this study, a total of 121 isolates of Fusarium fujikuroi, the causal agent of rice bakanae disease (RBD), were collected from various geographical regions of China, and their sensitivity to a novel succinate dehydrogenase inhibitor (SDHI)fungicide ‘pydiflumetofen’ was evaluated. The 50% effective concentration (EC50) value of pydiflumetofen for mycelial growth suppression ranged from 0.0101 to 0.1012 μg/ml and for conidial germination inhibition ranged from 0.0051to 0.1082 μg/ml. Pydiflumetofen treated hyphae showed contortion and increased branching, cell membrane permeability, and glycerol content significantly. The result of electron microscope transmission indicated that pydiflumetofen damaged the mycelial cell wall and the cell membrane, and almost broken up the cells, which increased the intracellular plasma leakage. There was no cross-resistance between pydiflumetofen and the widely used fungicides such as carbendazim, prochloraz, and phenamacril. Pydiflumetofen was found safe to seeds and rice seedlings of four rice cultivars, used up to 400 μg/ml. Seed treatment significantly decreased the rate of diseased plants in the greenhouse as well as in field trials in 2017 and 2018. Pydiflumetofen showed superb results against RBD, when used at 10 or 20 g a.i./100 kg of treated seeds, providing over 90% control efficacy (the highest control efficacy was up to 97%), which was significantly higher than that of 25% phenamacril (SC) at 10g or carbendazim at 100 g. Pydiflumetofen is highly effective against F. fujikuroi growth and sporulation as well as RBD in the field.

scholarly journals Characterization of Wild-Type and Cidofovir-Resistant Strains of Camelpox, Cowpox, Monkeypox, and Vaccinia Viruses

2002 ◽  
Vol 46 (5) ◽  
pp. 1329-1335 ◽  
Author(s):  
Donald F. Smee ◽  
Robert W. Sidwell ◽  
Debbie Kefauver ◽  
Mike Bray ◽  
John W. Huggins
Keyword(s):  
Active Form ◽  
Cross Resistance ◽  
Cowpox Virus ◽  
Wild Type ◽  
Biochemical Basis ◽  
Virus Challenge ◽  
Antiviral Compounds ◽  
Vaccinia Viruses ◽  
Resistant Strains

ABSTRACT Cidofovir {[(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine] [HPMPC]}-resistant forms of camelpox, cowpox, monkeypox, and vaccinia viruses were developed by prolonged passage in Vero 76 cells in the presence of drug. Eight- to 27-fold-higher concentrations of cidofovir were required to inhibit the resistant viruses than were needed to inhibit the wild-type (WT) viruses. Resistant viruses were characterized by determining their cross-resistance to other antiviral compounds, examining their different replication abilities in two cell lines, studying the biochemical basis of their drug resistance, and assessing the degrees of their virulence in mice. These viruses were cross resistant to cyclic HPMPC and, with the exception of vaccinia virus, to (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)adenine. Three of the four resistant cowpox and monkeypox viruses exhibited reduced abilities to infect and replicate in 3T3 cells compared to their abilities in Vero 76 cells. Compared to the WT virus polymers the resistant cowpox virus DNA polymerase was 8.5-fold less sensitive to inhibition by cidofovir diphosphate, the active form of the drug. Intracellular phosphorylation of [3H]cidofovir was not stimulated or inhibited by infection with resistant cowpox virus. In intranasally infected BALB/c mice, WT cowpox virus was 80-fold more virulent than the resistant virus. Cidofovir treatment (100 mg/kg of body weight, given one time only as early as 5 min after virus challenge) of a resistant cowpox virus infection could not protect mice from mortality. However, the drug prevented mortality in 80 to 100% of the mice treated with a single 100-mg/kg dose at 1, 2, 3, or 4 days after WT virus challenge. By application of these results to human orthopoxvirus infections, it is anticipated that resistant viruses may be untreatable with cidofovir but their virulence may be attenuated. Studies will need to be conducted with cidofovir-resistant monkeypox virus in monkeys to further support these hypotheses.

Occurance, pathogenicity, characterization of Fusarium fujikuroi causing rice bakanae disease from Odisha and in vitro management

2018 ◽  
Vol 55 (1) ◽  
pp. 214 ◽  
Author(s):  
S Raghu ◽  
Manoj K Yadav ◽  
SR Prabhukarthikeyan ◽  
Mathew S Baite ◽  
Srikanta Lenka ◽  
...  
Keyword(s):  
Fusarium Fujikuroi ◽  
Bakanae Disease

scholarly journals PIRA-PCR for Detection of Fusarium fujikuroi Genotypes with Carbendazim-Resistance Alleles

Plant Disease ◽  
2015 ◽  
Vol 99 (9) ◽  
pp. 1241-1246 ◽  
Author(s):  
Zhen Zhang ◽  
Zihao Chen ◽  
Yiping Hou ◽  
Yabing Duan ◽  
Jianxin Wang ◽  
...  
Keyword(s):  
Restriction Analysis ◽  
Point Mutations ◽  
Enzyme Digestion ◽  
Gibberella Fujikuroi ◽  
Fusarium Fujikuroi ◽  
Chain Reaction ◽  
Bakanae Disease ◽  
Resistant Strains ◽  
Polymerase Chain ◽  
Enzyme Recognition

Carbendazim, a methyl benzimidazole carbamate (MBC)-group fungicide, has been used to control rice bakanae disease, caused by Fusarium fujikuroi (teleomorph: Gibberella fujikuroi), for decades in China. Previous research revealed that point mutations (E198V, GAG to GTG at codon 198, and F200Y, TTC to TAC at codon 200) of the β2-tubulin gene conferred resistance of F. fujikuroi to MBC. In this study, primer-introduced restriction analysis polymerase chain reaction (PIRA-PCR) was developed to determine genotypes with resistance of F. fujikuroi to MBC. A PCR template of each strain was created by an outer primer pair. Fragments with 177 bp (for mutation at codon 235) and 146 bp (for E198V) were amplified by nested PCR, with two inner primer pairs designed and synthesized according to the nucleotide sequence of β2-tubulin for further enzyme digestion validation, respectively. AccII and PmaCI restriction enzyme recognition sites were introduced artificially by inner primers to differentiate MBC-sensitive and -resistant strains, respectively. The sensitivity of each strain to MBC was indirectly determined by analyzing electrophoresis patterns of the resulting amplified fragments after simultaneous digestion by both AccII and PmaCI. PIRA-PCR produced the same result as conventional methods in 6% of the time. PIRA-PCR is a sensitive and effective method for genotyping resistance alleles of F. fujikuroi strains to MBC.

Molecular diagnosis of thiophanate-methyl resistant strains of Fusarium fujikuroi in Japan

Plant Disease ◽  
2021 ◽  
Author(s):  
Fangjing Li ◽  
Ryoji Komura ◽  
Chiharu Nakashima ◽  
Masafumi Shimizu ◽  
Koji Kageyama ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Molecular Diagnosis ◽  
Previous Investigation ◽  
Inhibitory Concentration ◽  
Isothermal Amplification ◽  
Fusarium Fujikuroi ◽  
Bakanae Disease ◽  
Thiophanate Methyl ◽  
Loop Mediated Isothermal Amplification ◽  
Resistant Strains

Fusarium fujikuroi is the pathogen of rice bakanae disease, and is subclassified into gibberellin and fumonisin groups (G- and F-groups). Thiophanate-methyl, a benzimidazole fungicide, has been used extensively to control F. fujikuroi. Previous investigation showed that F-group strains are thiophanate-methyl sensitive (TMS), while most G-group strains are thiophanate-methyl resistant (TMR) in Japan. The minimum inhibitory concentration (MIC) in TMS strains was 1–10 μg mL-1, while that in TMR strains was higher than 100 μg mL-1. E198K and F200Y mutations in β2-tubulin were detected in TMR strains. A loop-mediated isothermal amplification-fluorescent loop primer (LAMP-FLP) method was developed for diagnosis of these mutations, and was applied to 37 TMR strains and 56 TMS strains. The result indicated that 100% of TMR strains were identified as having either the E198K mutation (41%) or the F200Y mutation (59%), while none of the TMS strains tested showed either mutation. We found one remarkable TMR strain in the F-group which had a F200Y mutation. These results suggest that E198K and F200Y mutations in β2-tubulin contribute to thiophanate-methyl resistance in F. fujikuroi.

scholarly journals Baseline sensitivity and resistance risk assessment of Valsa mali to pyraclostrobin

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Hao Feng ◽  
Shuai Wang ◽  
Zhaoyang Liu ◽  
Jianqiang Miao ◽  
Mingxia Zhou ◽  
...  
Keyword(s):  
Geographic Location ◽  
Hyphal Growth ◽  
Dry Weight ◽  
Mean Value ◽  
Cross Resistance ◽  
Baseline Sensitivity ◽  
Resistance Risk ◽  
Quinone Outside Inhibitor ◽  
Significant Difference ◽  
Valsa Mali

Abstract Pyraclostrobin, a quinone outside inhibitor (QoI) fungicide, has been registered to control apple tree Valsa canker (AVC) caused by Valsa mali in China. However, there is no data available regarding the resistance risk of V. mali to pyraclostrobin. In this study, the sensitivities of 120 V. mali isolates to pyraclostrobin were detected. The isolates were collected from apple orchards with no application of pyraclostrob at six provinces in China during 2013–2015, and showed similar sensitivity to pyraclostrobin. The EC50 values of these 120 V. mali isolates to pyraclostrobin ranged from 0.0014 to 0.0240 μg/mL, indicating an excellent inhibitory efficacy of pyraclostrobin to the pathogen. The EC50 values were distributed as a unimodal curve with a mean value of 0.0091 μg/mL, and the mean EC50 displayed correlation with geographic location. Meanwhile, three pyraclostrobin-resistant mutants (PR mutants) of V. mali were obtained using fungicide adaption method, with a resistance factor (RF) of 41.0, 56.8 and 22.0, respectively. The mutants showed a stable resistance to pyraclostrobin after 10 transfers on pyraclostrobin-free medium. Comparing with the corresponding parental isolates, the hyphal growth, mycelial dry weight and pathogenicity of PR mutants were significantly reduced, but the number of propagules showed no significant difference. More importantly, no cross-resistance of PR mutants to pyraclostrobin, tebuconazole, difenoconazole, imazalil and thiophanate-methyl was detected. In conclusion, V. mali showed a moderate risk to pyraclostrobin, and pyraclostrobin could be used as an alternative fungicide to control AVC in the field in China.

Caracterização da Peneira Média em Clones de Coffea canephora

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 28-31
Author(s):  
Darlan Darlan Sanches Barbosa Alves ◽  
Victor Mouzinho Spinelli ◽  
Marcos Santana Moraes ◽  
Carolina Augusto De Souza ◽  
Rodrigo da Silva Ribeiro ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Block Design ◽  
Coffea Canephora ◽  
Coffee Production ◽  
Randomized Block Design ◽  
Significant Difference ◽  
The Mean ◽  
Four Blocks ◽  
Selection Of

Introdução: O estado de Rondônia se destaca como tradicional produtor de café, sendo o segundo maior produtor brasileiro de C. canephora. No melhoramento genético de C. canephora, a seleção de plantas de elevada peneira média está associada à bebida de qualidade superior. Objetivos: O objetivo desse estudo foi avaliar a variabilidade genética de clones de C. canephora para o tamanho dos grãos, mensurado a partir da avaliação da peneira média (PM). Materiais e Métodos: Para isso, foi conduzido ao longo de dois anos agrícolas experimento no campo experimental da Embrapa no município de Ouro Preto do Oeste-RO, para a avaliação da peneira média de 130 genótipos (clones) com características das variedades botânicas Conilon, Robusta e híbridos intervarietais. O delineamento experimental utilizado foi de blocos ao acaso, com quatro repetições de quatro plantas por parcela. Resultados: Não houve resultados significativos para a interação clones X anos, indicando uma maior consistência no comportamento das plantas ao longo do tempo. Porém foram observadas diferenças significativas para o tamanho dos grãos entre os genótipos avaliados, possibilitando selecionar genótipos superiores. Conclusão: Os genótipos agruparam-se em cinco classes de acordo com o teste de média, subsidiando a caracterização de um gradiente de variabilidade da característica avaliada ABSTRACTIntroduction: Coffea canephora accounts for approximately 35% of the world's coffee production. The state of Rondônia stands out as a traditional coffee producer, being the second largest Brazilian producer of C. canephora. In the classical genetic improvement of C. anephora, the selection of plants of high average sieve is associated with a drink of superior quality. Objectives: The objective of this udy was to evaluate the genetic variability of Coffea canephora clones for the agronomic medium sieve (PM). Materials and Methods: The experiment was conducted in the experimental field of Embrapa, municipality of OuroPreto do Oeste-RO, located at coordinates 10º44'53 "S and 62º12'57". One hundred thirty genotypes (clones) of botanical characteristics Conilon, Robusta and intervarietal hybrids were evaluated in the agricultural years 2013-2014 and 2014-2015. The experimental design was a randomized block design with four blocks and four plants per plot, spacing 3.5 x 1.5 meters between plants. Results: Significant difference was found for the grain size. According to the F test, at 5% probability, the genotypes were grouped into five classes according to the mean test. Conclusion: The results obtained subsidized the characterization of a variability gradient of the evaluated trait.

scholarly journals A global non-invasive methodology for the phenotyping of potato under water deficit conditions using imaging, physiological and molecular tools

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
M. Musse ◽  
G. Hajjar ◽  
N. Ali ◽  
B. Billiot ◽  
G. Joly ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Soil Conditions ◽  
Growth Stages ◽  
Dry Matter Content ◽  
Tuber Growth ◽  
Non Invasive ◽  
Potato Plants ◽  
Significant Difference

Abstract Background Drought is a major consequence of global heating that has negative impacts on agriculture. Potato is a drought-sensitive crop; tuber growth and dry matter content may both be impacted. Moreover, water deficit can induce physiological disorders such as glassy tubers and internal rust spots. The response of potato plants to drought is complex and can be affected by cultivar type, climatic and soil conditions, and the point at which water stress occurs during growth. The characterization of adaptive responses in plants presents a major phenotyping challenge. There is therefore a demand for the development of non-invasive analytical techniques to improve phenotyping. Results This project aimed to take advantage of innovative approaches in MRI, phenotyping and molecular biology to evaluate the effects of water stress on potato plants during growth. Plants were cultivated in pots under different water conditions. A control group of plants were cultivated under optimal water uptake conditions. Other groups were cultivated under mild and severe water deficiency conditions (40 and 20% of field capacity, respectively) applied at different tuber growth phases (initiation, filling). Water stress was evaluated by monitoring soil water potential. Two fully-equipped imaging cabinets were set up to characterize plant morphology using high definition color cameras (top and side views) and to measure plant stress using RGB cameras. The response of potato plants to water stress depended on the intensity and duration of the stress. Three-dimensional morphological images of the underground organs of potato plants in pots were recorded using a 1.5 T MRI scanner. A significant difference in growth kinetics was observed at the early growth stages between the control and stressed plants. Quantitative PCR analysis was carried out at molecular level on the expression patterns of selected drought-responsive genes. Variations in stress levels were seen to modulate ABA and drought-responsive ABA-dependent and ABA-independent genes. Conclusions This methodology, when applied to the phenotyping of potato under water deficit conditions, provides a quantitative analysis of leaves and tubers properties at microstructural and molecular levels. The approaches thus developed could therefore be effective in the multi-scale characterization of plant response to water stress, from organ development to gene expression.

scholarly journals Crystallization of Random Metallocene-Catalyzed Propylene-Based Copolymers with Ethylene and 1-Hexene on Rapid Cooling

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2091
Author(s):  
Daniela Mileva ◽  
Jingbo Wang ◽  
René Androsch ◽  
Katalee Jariyavidyanont ◽  
Markus Gahleitner ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Metallocene Catalyst ◽  
Nucleating Agent ◽  
Random Copolymers ◽  
Rapid Cooling ◽  
Significant Difference ◽  
Chip Calorimetry ◽  
High Cooling Rates ◽  
Fast Scanning Chip Calorimetry

Propylene-based random copolymers with either ethylene or 1-hexene as comonomer, produced using a metallocene catalyst, were studied regarding their crystallization behaviors, with a focus on rapid cooling. To get an impression of processing effects, fast scanning chip calorimetry (FSC) was used in addition to the characterization of the mechanical performance. When comparing the comonomer type and the relation to commercial grades based on Ziegler–Natta-type catalysts, both an interaction with the catalyst-related regio-defects and a significant difference between ethylene and 1-hexene was observed. A soluble-type nucleating agent was found to modify the behavior, but to an increasingly lesser degree at high cooling rates.

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