Aconitum kusnezoffii is a perennial herbaceous medicinal plant of the family Ranunculaceae, with unique medicinal value. Damping off is one of the most important seedling diseases affecting A. kusnezoffii, occurring widely and often causing large-scale seedling death in the field. To clarify the species of the pathogen causing damping off in A. kusnezoffii and to formulate an effective control strategy, this study conducted pathogen identification, research on biological characteristics, and evaluation of fungicide inhibitory activity. Through morphological characteristics, cultural traits, and phylogenetic tree analysis, the pathogen causing damping off in A. kusnezoffii was identified as Rhizoctonia solani, belonging to the AG5 anastomosis group. The optimal temperature for mycelial growth of the pathogen was 25-30 ℃, with OA medium as the most suitable medium, pH 8 as the optimal pH, and sucrose and yeast as the best carbon and nitrogen sources, respectively. The effect of light on mycelial growth was not significant. In evaluating the inhibitory activity of 45 chemical fungicides, including 30% hymexazol, and 4 biogenic fungicides, including 0.3% eugenol, it was found that 30% thifluzamide and 50% fludioxonil had significantly better inhibitory effects on R. solani than other tested agents, with EC_(50) values of 0.129 6,0.220 6 μg·mL~(-1), respectively. Among the biogenic fungicides, 0.3% eugenol also showed an ideal inhibitory effect on the pathogen, with an EC_(50) of 1.668 9 μg·mL~(-1). To prevent the development of resistance in the pathogen and to reduce the use of chemical fungicides, it is recommended that the three fungicides above be used in rotation during production. These findings provide a theoretical basis for the accurate diagnosis and effective control strategy for R. solani causing damping off in A. kusnezoffii.
Fungicides, Industrial/pharmacology* ; Plant Diseases/microbiology* ; Rhizoctonia/growth & development* ; Aconitum/microbiology* ; Phylogeny ; Mycelium/growth & development*

In recent years, potato scab caused by pathogenic Streptomyces spp. has become widespread globally, with increasing damage severely compromising the commercial value and storability of tubers. The pathogens are transmitted through the soil and seeds of potato, while existing control technologies have demonstrated limited efficacy in preventing the colonization and spread of pathogens, which pose a critical bottleneck in the sustainable development of the potato industry. This study systematically examines the pathogen characteristics and pathogenic mechanisms, evaluates the impacts of soil nutrients and microbial community structure on disease severity, and analyzes limitations in current chemical control, biological control, and disease-resistant variety breeding approaches. We propose an integrated control strategy of disease-resistant varieties, phosphorus fertilizer reduction, fertilizer efficiency enhancement, and phosphorus-soluble antagonistic fungicides, aiming to provide novel research perspectives for achieving effective prevention and control of potato scab.
Solanum tuberosum/microbiology* ; Plant Diseases/prevention & control* ; Streptomyces/pathogenicity* ; Disease Resistance ; Fungicides, Industrial/pharmacology* ; Fertilizers ; Soil Microbiology

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

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

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

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

During the process of growth, harvesting, transportation, processing and storage, Chinese herbal medicines (CHMs) can be easily contaminated by fungi and their metabolites like mycotoxins, which not only express negative effects on the quality and safety of CHMs and their processed products, but also pose great threats to human health. Now, some chemical synthetic fungicides have been frequently used to control the growth of fungi and accumulation of mycotoxins in the preservation of CHMs. However, the concentration and type of chemical fungicides allowed for postharvest application are restricted due to the disadvantages of their high residual toxicity, long degradation period and pollution to the environment and so on. Therefore, it is critical to research and develop some highly effective, safe and non-toxic, natural, environment-friendly fungistatic agents from plants to prevent CHMs from being contaminated by fungi and mycotoxins. The paper reviews mycotoxins and their harmfulness, the effective compounds of fungistatic plants as well as the antifungal mechanism to provide scientific evidences for developing novel and effective fungistatic agents plants. Then, the application prospect of fungistatic agents from plants in the preservation of CHMs was discussed.
Animals ; Fungi ; drug effects ; metabolism ; Fungicides, Industrial ; pharmacology ; Humans ; Mycotoxins ; metabolism ; toxicity ; Plant Diseases ; microbiology ; prevention & control ; Plant Extracts ; pharmacology ; Plants, Medicinal ; chemistry ; microbiology ; Preservation, Biological ; methods

In order to obtain the fungicides with minimal impact on efficiency of mycorrhizal symbiosis, the effect of five fungicides including polyoxins, jinggangmycins, thiophanate methylate, chlorothalonil and carbendazim on the growth of medicinal plant and efficiency of mycorrhizal symbiosis were studied. Pot cultured Glycyrrhiza uralensis was treated with different fungicides with the concentration that commonly used in the field. 60 d after treated with fungicides, infection rate, infection density, biomass indexes, photosyn- thetic index and the content of active component were measured. Experimental results showed that carbendazim had the strongest inhibition on mycorrhizal symbiosis effect. Carbendazim significantly inhibited the mycorrhizal infection rate, significantly suppressed the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. Polyoxins showed the lowest inhibiting affection. Polyoxins had no significant effect on mycorrhizal infection rate, the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. The other three fungicides also had an inhibitory effect on efficiency of mycorrhizal symbiosis, and the inhibition degrees were all between polyoxins's and carbendazim's. The author considered that fungicide's inhibition degree on mycorrhizal effect might be related with the species of fungicides, so the author suggested that the farmer should try to choose bio-fungicides like polyoxins.
Fungi ; drug effects ; growth & development ; physiology ; Fungicides, Industrial ; pharmacology ; Glycyrrhiza uralensis ; chemistry ; growth & development ; microbiology ; physiology ; Mycorrhizae ; drug effects ; growth & development ; physiology ; Plant Extracts ; chemistry ; Symbiosis ; drug effects

The mycelium growth and sporulation in different temperature, pH value and light conditions were detected by using the crossing and haemocytometer method. The toxicity of five fungicides to Fusarium oxysporum was tested by mycelia growth method, so as to provide the reference for prevention and control against F. oxysporum. The optimum temperature and pH value of F. oxysporum to grow and spore were 28 degrees C and 6-7. Alternating light and darkness promoted growth and sporulation of bacterial colony. As for five fungicides, the EC50 of tebuconazole was 10.02 mg x L(-1), 92.50 times as much as carbendazim. The EC50 of myclobutanil and Fuxing was 91.23, 96.68 mg x L(-1), respectively. Tebuconazole showed the most tremendous inhibitory effect and control efficiency on F. oxysporum.
Fungicides, Industrial ; pharmacology ; Fusarium ; drug effects ; growth & development ; Mycelium ; drug effects ; growth & development ; Orchidaceae ; microbiology ; Plant Diseases ; microbiology ; Spores, Fungal ; drug effects ; growth & development