This study aimed to establish the baseline sensitivity of Botrytis cinerea from Panax ginseng to prochloraz, and ensure the fitness of prochloraz-resistant mutants and the cross-resistance of B. cinerea to prochloraz and commonly used fungicides for the prevention and control of gray mold including boscalid, pyraclostrobin, iprodione, and pyrimethanil. The sensitivity of B. cinerea from P. ginseng to fungicides was determined by the mycelial growth rate method. The prochloraz-resistant mutants were screened out through fungicide domestication and ultraviolet(UV) induction. The fitness of resistant mutants was determined through the stability of subculture, mycelial growth rate, and pathogenicity test. The cross-resistance between prochloraz and the four fungicides was determined by Person correlation analysis. The results showed that all B. cinerea strains tested were sensitive to prochloraz, and the EC_(50) value ranged from 0.004 8 to 0.062 9 μg·mL~(-1), with an average of 0.022 μg·mL~(-1). The sensitivity frequency distribution diagram showed that 89 B. cinerea strains were located within the main peak with a continuous single peak curve, and the average EC_(50) value of 0.018 μg·mL~(-1) was taken as the baseline sensitivity of B. cinerea to prochloraz. The fungicide domestication and UV induction obtained 6 resistant mutants, among which 2 strains were unstable and the other 2 strains showed decreased resistance after multiple generations of culture. Furthermore, the mycelial growth rate and spore yield of all resistant mutants were lower than those of their parents, and the pathogenicity of most mutants was lower than that of their parents. In addition, prochloraz had no obvious cross-resistance with boscalid, pyraclostrobin, iprodione, and pyrimethanil. In conclusion, prochloraz has great potential for controlling gray mold in P. ginseng, and the resistance risk of B. cinerea to prochloraz is low.
Humans ; Panax ; Fungicides, Industrial

During the high-temperature and rainy season from June to October in 2017-2019,serious southern blight broke out in the Cynanchum stauntonii planting area in Tuanfeng county,Hubei province,which had a great impact on the yield and quality of medicinal materials. In this study,the pathogen of C. stauntonii was isolated,purified,and identified,and the pathogenicity was tested according to Koch's postulates. Meanwhile,the biological characteristics of the pathogen were analyzed. On this basis,the effective fungicides were screened in laboratory. Finally,the pathogen( BQ-1) was identified as Athelia rolfsii( Deuteromycotina,Basidiomycota,anamorph: Sclerotium rolfsii). The optimum growth conditions for BQ-1 were 25-30 ℃,p H 5-8,and alternating light and dark.The effective chemical fungicides were lime-sulphur-synthelic-solution( LSSS) and flusilazole,and the effective botanical fungicide was osthole. BQ-1 was highly homologous to the pathogen HS-1 of peanut southern blight,with the similarity of 18 S r DNA and TEF sequences at 99. 09%. The southern blight in C. stauntonii might be resulted from that in peanut. In the production of C. stauntonii,the following measures should be taken: avoiding rotation or neighboring with peanut,draining water from June to October to reduce humidity,and reasonably applying fungicides.
Basidiomycota ; Cynanchum ; Fungicides, Industrial/pharmacology* ; Humidity

In Hezhang county, Guizhou province, black spot tends to occur to Aconitum carmichaelii in the hot rainy summer, with the incidence up to 50%-70%, seriously impacting the yield and quality of the medicinal material. Thus, this study aims to clarify the pathogen and the occurrence characteristics. To be specific, the pathogen was isolated and identified according to Koch's postulates and the pathogenicity and biological characteristics were determined. In addition, the sensitivity of the pathogen to four microbial fungicides, four botanical fungicides, and five chemical fungicides was determined with the mycelium growth rate method for the purpose of screening out optimal fungicides. The pathogen was identified as Alternaria alternate, as evidenced by the similar colony morphology and microscopic characteristics and 99.55%-100% similarity in sequences of rDNA-ITS, LSU, 18S, and TEF of the two. The optimum growth conditions for A. alternata were 28 ℃, pH 8, and continuous darkness. Bacillus subtilis had strong inhibitory effect on the pathogen, and the inhibition rate was more than 90% when the concentration was 1 mg·L~(-1). In addition, difenoconazole and quinoline copper can also control the pathogen, with median effective concentration(EC_(50)) of 2.92 and 9.02 mg·L~(-1), respectively. This study lays a theoretical basis for the field control of black spot in A. carmichaelii.
Aconitum ; Alternaria ; Fungicides, Industrial/pharmacology* ; Mycelium

Aims: Biocontrol of fungal plant pathogens using beneficial microorganisms is a safer alternative over synthetic fungicides. PHP12 is a bacterial strain isolated from healthy oil palm rhizosphere and is closely related to the recently described Burkholderia stagnalis, a member of the Burkholderia cepacia complex. This study aimed to characterize the antifungal activity spectrum of PHP12 and identify the antifungal compounds produced by the strain. Methodology and results: The antifungal activity of PHP12 was characterized by growing fungal strains in the presence and absence of PHP12 and measuring the radius of the antifungal zone. PHP12 inhibited the growth of fungal pathogens including Ganoderma boninense, Curvularia oryzae, Phellinus noxius and Colletotrichum capsici. However, PHP12 did not inhibit the growth of Trichoderma asperellum, a known fungal biocontrol agent. The antifungal compounds of PHP12 were precipitated using ammonium sulfate and further purified with HPLC followed by identification using Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC/ESI-MS). The LC/ESI-MS analysis showed the presence of an oligopeptide with a molecular weight of 1210.63 Da. The peptide consists of heavily modified amino acids that are linked by a hexose residue. Conclusion, significance and impact of study Although characteristics of the antifungal compounds are similar to other antifungal peptides from Burkholderia such as occidiofungin, there have been no reports of antifungal peptides from B. stagnalis with the corresponding molecular weight or fragmentation profile. The novelty of the compound, as well as its antifungal spectrum, makes PHP12 an interesting strain to be investigated further as a biocontrol agent.
Fungicides, Industrial ; Burkholderia cepacia complex--pathogenicity

Arbuscular mycorrhizal fungi provided is beneficial to Salvia miltiorrhiza for increasing yield, promoting the accumulation of active ingredients, and alleviating S. miltiorrhiza disease etc. However, the application of fungicides will affect the benefit of arbuscular mycorrhizal fungi and there is little research about it. This article study the effect of four different fungicides: carbendazim, polyoxin, methyl mopazine, and mancozeb on mycorrhiza benefit to S. miltiorrhiza by the infection intensity of arbuscular mycorrhizal fungi, the growth of S. miltiorrhiza, and the content of active ingredients. RESULTS:: showed that different fungicides had different effects. The application of mancozeb had the strongest inhibitory effect on the mycorrhizal benefit to S. miltiorrhiza. Mancozeb significantly reduced the mycorrhizal colonization and the beneficial effect of arbuscular mycorrhizal fungi on the growth and the accumulation of active components of S. miltiorrhiza. The application of polyoxin had no significant effect on mycorrhizal colonization. Instead, it had a synergistic effect with the mycorrhizal benefit to promoting the growth and accumulation of rosmarinic acid of S. miltiorrhiza. The inhibitory strengths of four fungicides are: mancozeb>thiophanate methyl, carbendazim>polyoxin. Therefore, we recommend applying biological fungicides polyoxin and avoid applying chemical fungicides mancozeb for disease control during mycorrhizal cultivation of S. miltiorrhiza.
Fungicides, Industrial/pharmacology* ; Mycorrhizae ; Plant Roots ; Salvia miltiorrhiza ; Symbiosis

The leaf spot of Belamcanda chinensis often appears in May to June and spreads rapidly during the flowering stage(July to September) in the cultivation fields, seriously affecting the yield and quality of B. chinensis. To identify and characterize the pathogens of the leaf spot, we isolated two species of Alternaria, identified them according to Koch's postulates, and tested their pathogenicity and biological characteristics. Furthermore, we determined the inhibitory effects of 6 chemical fungicides, 1 plant fungicide, and 3 microbial fungicides on the pathogens by using mycelial growth rate and plate confrontation method to select the appropriate control agents. The results showed that the two pathogens causing B. chinensis leaf spot were Alternaria tenuissima and A. alternata. The conidia of A. tenuissima often formed long chains with no or a few branches, while those of A. alternata often formed short branched chains. The optimum growth temperature of both A. tenuissima and A. alternata was 25 ℃. The two pathogens grew well in alkaline environment. The indoor fungicide screening experiments showed that 40% flusilazole had good inhibitory effects on the two pathogens, with the EC_(50) values of 12.42 mg·L~(-1) and 12.78 mg·L~(-1) for A. tenuissima and A. alternata, respectively. The results of this study provide a theoretical basis for the subsequent theoretical research and field control of B. chinensis leaf spot.
Fungicides, Industrial/pharmacology* ; Research ; Iris Plant ; Spores, Fungal ; Mycelium

In summer in 2020, Pinellia ternata in many planting areas in Hubei suffered from serious southern blight, as manifested by the yellowing and wilted leaves and rotten tubers. This study aims to identify the pathogen, clarify the biological characteristics of the pathogen, and screen fungicides. To be specific, the pathogen was isolated, purified, and identified, and the pathogenicity was detected according to the Koch's postulates. Moreover, the biological characteristics of the pathogen were analyzed. Furthermore, PDA plates and seedlings were used to determine the most effective fungicides. The results showed that the mycelia of the pathogen were white and villous with silk luster, which produced a large number of white to black brown sclerotia. The pathogen was identified as Athelia rolfsii by morphological observation and molecular identification based on LSU and TEF gene sequences. The optimum growth conditions for A. rolfsii were 30 ℃ and pH 5-8, and the optimum conditions for the germination of sclerotia were 25 ℃ and pH 7-9. Bacillus subtilis, difenoconazole, and flusilazole were identified as effective fungicides with PDA, and their half maximal effective concentration(EC_(50)) was all less than 5 mg·L~(-1). The effective fungicides screened with the seedlings were hymexazol and difenoconazole. Based on the screening experiments, difenoconazole can be used as the main agent for the prevention and treatment of southern blight.
Pinellia/genetics* ; Fungicides, Industrial/pharmacology* ; Seedlings ; Bacillus subtilis ; Mycelium

In order to establish a fast and accurate method for novel DMIs fungicide screening, lanosterol 14alpha-demethylase of Magnaporthe grisea expressed in E. coli was used as target enzyme and the DMI fungicides diniconazole, tebuconazole, triadimenol and triadimefon were used as representative fungicides, the effects of enzyme activity, enzyme purity and concentration on the binding spectra were investigated. The results showed that active enzyme, elimination of interference of other P450s and proper enzyme concentration were necessary for obtaining accurate binding spectra. The Kd values of diniconazole, tebuconazole, triadimenol and triadimefon were 0.143 micromol/L, 0.24 micromol/L, 0.257 micromol/L and 0.307 micromol/L respectively, which significantly correlated to their 120h-EC50 values on the growth of Magnaporthe grisea. The results indicated that the binding spectra of fungicide and lanosterol 14alpha-demethylase can serve as a reliable and fast method for novel fungicide screening.
Cytochrome P-450 Enzyme System ; metabolism ; Fungicides, Industrial ; pharmacology ; Spectrophotometry ; methods ; Sterol 14-Demethylase ; Triazoles ; pharmacology

Fungal pathogens represent major problems for human health and agriculture. As eukaryotic organisms, fungi share some important features with mammalian cells. Therefore, current anti-fungal antibiotics often can not distinguish between fungi and mammalian cells, resulting in serious side effects in mammalian cells. Accordingly, there is strong impetus to develop antifungal alternatives that are both safe and effective. The E1 family of colicin are channel-forming bacteriocins produced by Escherichia coli, which are bactericidal only to E. coli and related species. To target the channel-forming domain of colicin to fungal cell membrane, we engineered a sexual mating pheromone of Candida albicans, α-factor pheromone to colicin Ia. A peptide was constructed consisting of an α mating pheromone of C. albicans fused to the channel-forming domain of colicin Ia to create a new fusion protein, pheromonicin-CA (PMC-CA). Indirect immunolabeling showed that the PMC-CA bound to fungal cells and inhibited growth in the laboratory and field. In the field, the protective activity of pheromonicin against rice blast disease was significantly greater, on a molar basis, than that of triazoles, tricyclazole or isoprothiolane. These results suggest that fusion peptides may be of value as fungicidal agents under agricultural conditions.
Candida albicans ; chemistry ; Colicins ; chemistry ; Fungicides, Industrial ; chemistry ; Mating Factor ; Peptides ; chemistry ; Protein Engineering

This study was aimed to clarify the toxicity indoor and inhibition effect of biocontrol strain NJ13 and its mixture with chemical fungicides against Fusarium solani causing ginseng root rot. The method of mycelial growth rate and Sun Yunpei method were used to determine the indoor toxicity and co-toxicity coefficient of strain NJ13 and their mixture with chemical pesticides against F. solani. The dual culture assay method,mixed culture method and microscopic observation were used to determine the sporulation and germination of spores and mycelial growth and morphological change of hyphae of F. solani treated by strain NJ13. The results of toxicity indoor showed that strain NJ13 had the best inhibitory effect on pathogen,and its EC_(50) value was 0. 071 mg·L~(-1). It was all synergistic for antifungal effect that strain NJ13 was mixed with propiconazole and difenoconazole respectively with a range from 1 ∶4 to 4 ∶1( volume ratio). Both of optimal ratios were 1 ∶1,and the co-toxicity coefficients were 848. 70 and 859. 73,respectively. The strain NJ13 could inhibit the sporulation,germination and mycelial growth of F. solani. The biocontrol strain NJ13 had an inhibition effect on F. solani,and the optimal antifungal ratio of strain NJ13 mixed with propiconazole and difenoconazole was obtained.
Bacteria ; Biological Control Agents ; Fungicides, Industrial ; Fusarium ; pathogenicity ; Panax ; microbiology ; Plant Roots ; microbiology