The biocontrol efficacy of Bacillus amyloliquefaciens FS6 against seedling diseases and gray mold of ginseng (Panax ginseng), as well as application techniques, were evaluated in a series of field trials. FS6 fermentation broth showed a strong antagonistic effect against the ginseng fungal pathogens, and the inhibition rates on mycelial growth and spore germination were 84 to 88% and 71 to 72%, respectively. Field evaluation showed that combination of seed and soil treatments exhibited better protection than that of individual treatment alone. FS6 wettable powder soil treatment in combination with thiamethoxam plus metalaxyl-M plus fludioxonil for seed coating performed the best, with >83% overall control efficacy for seedling diseases. FS6 had a long-acting effect of >78% control efficacy on ginseng gray mold at 30 days after the last application, almost 2.5- and 2-fold better than that of B. amyloliquefaciens B7900 wettable powder and cyprodinil, respectively. In addition, FS6 reduced the diversity and relative abundance of fungi and affected the fungi and bacterial composition in the rhizosphere soil of ginseng. Therefore, FS6 can be used to effectively control seedling diseases and gray mold in ginseng.

Ganoderma lucidum is one of very valuable herbal medicines in Asia. It belongs to the family Ganodermataceae, and is mainly used for prevention and treatment of nephritis, hypertension, bronchitis, tumorigenic affections, etc. Symptoms of cobweb caused by Cladobotryum mycophilum were observed on the cultivated G. lucidum, the incidence of infection exceeded the 30%. It resulted in serious losses in Jiaohe and Dunhua cities, Jilin Province, China in 2013. The disease occurred during the period of maturation of the fruit body of G. lucidum. Firstly, white cobweb-like hyphae appeared on the surface of the soils. Subsequently, the white hyphae grew and extended on the fruit body of G. lucidum. Finally, the entire fruit body decayed with gray-white to red-brown moulds. Small pieces of diseased fruit body were disinfested by soaking in 75% alcohol for 30 seconds and 0.1% HgCl2 for 1 minute, then rinsed three times in sterilized water and placed on potato dextrose agar (PDA) medium, incubated at 23°C. On PDA med...

Chinese ginseng (Panax ginseng) is a perennial Chinese herb of the Araliaceae family. It is found in the three northeast provinces of China. As a valuable restorative tonic, it is widely used in traditional Chinese medicine (Radad et al. 2006). In November 2015 and 2016, gray mold was observed on 10 to 35% of fresh ginseng roots in two storage facilities under complete darkness at 4oCin Ji An and Fu Song City, Jilin Province. Initial symptoms included light brown, water-soaked lesions on ginseng roots. Within 30 days, the diseased areas enlarged, with dense, abundant gray mycelia forming on lesions. To isolate the pathogen, small pieces of diseased roots were surface- disinfested in 3% NaClO for 2 min, rinsed twice in distilled water, plated on potato dextrose agar (PDA) and incubated at 22oC for five days. Sixteen isolates were recovered by single-spore isolation. Colony morphology was almost identical among all isolates. Representative isolate PG-S015 was grown on PDA under constant fluorescent light at...

Ginseng Alternaria leaf and stem blight (GALSB), caused by Alternaria alternata, poses a severe threat to ginseng cultivation. Although azoxystrobin is a cornerstone fungicide for GALSB management, the emergence of widespread adaptive resistance has severely curtailed its field efficacy. This study integrated molecular, transcriptomic, and genetic approaches to unravel the underlying resistance mechanisms. Targeted gene sequencing and molecular docking revealed that resistant strains harbor a conserved G143A point mutation in the AaCyt b protein. This mutation weakens the azoxystrobin–AaCyt b protein binding affinity by decreasing the binding energy from −8.31 to −7.08 kcal/mol. Additionally, comparative transcriptomics and RT-qPCR demonstrated pronounced upregulation of the alternative oxidase gene (AaAOX) and core energy metabolism pathways in resistant strain TYC8-2, with AaAOX expression increasing 4.45–6.91-fold. Fungicidal inhibition of AOX via salicylhydroxamic acid (SHAM) restored fungal sensitivity, increasing azoxystrobin sensitivity by 11.66-fold. Crucially, genetic knockout of AaAOX enhanced sensitivity by approximately 2.7 × 10⁴-fold. Phenotypic assays further established AaAOX as a multifunctional regulator; the AaAOX mutant exhibited attenuated virulence on ginseng leaves and increased sensitivity to oxidative and osmotic stresses (NaCl, H₂O₂, NaAc). We conclude that the G143A mutation in AaCyt b and the transcriptional overexpression of AaAOX act independently to drive azoxystrobin resistance in A. alternata. These findings provide comprehensive mechanistic insights to guide resistance monitoring, optimize fungicide applications, and develop precision strategies for GALSB management.

Fusarium root rot on ginseng is an important root disease that seriously affects ginseng (Panax ginseng) yield and quality. However, the species categories and distribution of Fusarium causing ginseng root rot in China have not been systematically examined. A total of 571 pure Fusarium isolates were obtained from 2018 to 2019 from 14 ginseng-producing regions in Jilin, Liaoning, and Heilongjiang provinces, China. Based on multilocus sequence analysis of ITS–tef1–rpb2 and morphological characteristics, the 571 Fusarium isolates were identified as F. oxysporum (accounting for 47.46% of the total isolates), F. solani (35.38%), F. equiseti (5.78%), F. proliferatum (2.80%), F. cerealis (1.75%), F. semitectum (1.75%), F. acuminatum (1.75%), F. redolens (1.58%), F. verticillioides (1.05%), and F. graminearum (0.70%). Among them, F. oxysporum and F. solani were the dominant species, and F. graminearum and F. verticillioides were first recorded on ginseng in China. The fungicides captan and hymexazol were tested in vitro for their inhibitory activities against 10 Fusarium species. All Fusarium species displayed enhanced sensitivity to captan compared with hymexazol. The protective effects of captan against ginseng root rot caused by F. oxysporum ranged from 94.07 to 97.78% at concentrations of 200, 400, and 600 μg·ml ⁻¹ ; however, its curative effects were much lower, ranging from 29.63 to 35.56%. In comparison, hymexazol exhibited protective effects of only 24.00 to 52.00% and curative effects of 16.00 to 45.33% at concentrations of 600 to 1,000 μg·ml ⁻¹ . In addition, microconidia were highly sensitive to both fungicides, compared with mycelia and macroconidia.