Fusarium head blight (FHB), caused by Fusarium graminearum, not only leads to severe yield losses but also poses a threat to food safety due to the mycotoxins produced by the pathogen. Since this disease is preventable but not curable, the current control mainly relies on chemical fungicides, the long-term use of which may lead to pathogen resistance and environmental pollution. To develop green control methods, we screened 13 biocontrol strains from the rhizosphere soil of wheat, among which strain No. 12 (identified as Pythium aphanidermatum) showed significant antifungal effects. In the plate confrontation test, this strain reduced the colony diameter of the pathogen by 69.2% (1.47 mm vs. 4.78 mm in the control group), with an inhibition rate of 77% (P < 0.01). Microscopic observation revealed obvious deformations in the pathogen hyphae, suggesting a lysing effect. The coleoptile experiment further confirmed that the pre-treatment with this strain reduced the incidence rate to 0. These findings provide new candidate strains for the biocontrol of FHB and offer a scientific basis for reducing the use of chemical fungicides and promoting sustainable agricultural development.
Triticum/growth & development* ; Fusarium/growth & development* ; Plant Diseases/prevention & control* ; Soil Microbiology ; Pest Control, Biological/methods* ; Pythium/physiology* ; Biological Control Agents ; Rhizosphere ; Fungicides, Industrial

Antifungal Agents ; metabolism ; Aspergillus ; growth & development ; Botrytis ; growth & development ; Fructose ; pharmacology ; Fusarium ; growth & development ; Penicillium ; growth & development

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

OBJECTIVEDetect the pathogenicity of fungi isolated from American ginseng seeds and select new fungicides against the pathogenic seed-born fungi.

METHODinoculate the isolates to American ginseng seedlings to detect the pathogenicity, and seeded the hyphae disk at the center of agar plate containing chemicals to do fungicide bioassay.

RESULTFusarium sp. isolate 5 and Alternara sp. isolate 13 had pathogenicity to American ginseng seedling. Sportak had the strongest inhibition to the two isolates, Carbendazim had better inhibition and Celest had weak inhibition.

CONCLUSIONSportak and Celest could be used as efficacious candidate chemicals to treat or coat the American ginseng seeds, and substitute Carbendazim, which has been used for many years, to control the diseases occurring in seedling stage of American ginseng.

Alternaria ; drug effects ; isolation & purification ; Benzimidazoles ; pharmacology ; Carbamates ; pharmacology ; Fungicides, Industrial ; pharmacology ; Fusarium ; drug effects ; isolation & purification ; Panax ; growth & development ; microbiology ; Plants, Medicinal ; growth & development ; microbiology ; Seedlings ; growth & development ; microbiology ; Seeds ; growth & development ; microbiology

OBJECTIVETo study influence of fungal elicitors on the biomass and ginseng saponin biosynthesis of hairy roots of Panax ginseng (HRPG).

METHODFungal elicitors were extracted from Colletorichum lagnarinm, Phoma filtrate, Fusarium oxysponum, Asperillus niger and culture with HRPG. The total ginseng sponin and four kinds of monomeric sponins were analysed by UV-spectrophotometry and RP-HPLC.

RESULTFungal elicitors coula not only can influence on HRPG biomass and total ginseng sponin, but also improve or decrease some monomeric sponin. The total ginseng sponin could be increased to 3.649% but Rg1 and Re could not be detected when A. niger elicitors wss 20 mg x L(-1) in the culture fluid.

CONCLUSIONFungal elicitor has specificity influence on secondary metabolite of HRPG. HRPG can biosynthesize specially active component by using specific fungal elicitor is used.

Aspergillus niger ; chemistry ; physiology ; Coculture Techniques ; Fusarium ; chemistry ; physiology ; Ginsenosides ; biosynthesis ; Panax ; growth & development ; metabolism ; microbiology ; Plant Roots ; growth & development ; metabolism ; microbiology ; Plants, Medicinal ; growth & development ; metabolism ; microbiology ; Polysaccharides ; isolation & purification ; pharmacology

OBJECTIVETo control the medicinal plant diseases with the preparation of Trichoderma harzianum.

METHODAntagonistic action of the preparation to the pathogens of the medicinal plants in vitro, and controling effects of the preparation on these diseases in greenhouse and in the field were tested.

RESULTThe test in vitro showed that Trichoderma harzianum, used as a biocontrol factor, had stronger antagonistic action to Fusarium equiseti, Sclerotinia sp. and Rhizoctonia solani which were the medicinal plant pathogens of Astragalus membranaceus, Glehnia littoralis and Panax quinquefolium respectively. Biological controling effects on sclerotium root rot of Glehnia littoralis were 83.6% and 72.5% respectively in greenhouse and in the field with the preparation of Trichoderma harzianum. And controling effects on root rot of Astragalus membranaceus and seedling damping-off of Panax quinquefolium were 80% and 60% respectively in the field. The dosage of the preparation used in the field was 10 g.m-2.

CONCLUSIONThe preparation of Trichoderma harzianum can be used as a substitute for such chemicals as Carbendazim. Using the preparation to control medicinal plant diseases provides a technical safeguard for the good agricultural practice of medicinal plants.

Apiaceae ; growth & development ; microbiology ; Ascomycota ; pathogenicity ; Astragalus membranaceus ; growth & development ; microbiology ; Fusarium ; pathogenicity ; Panax ; growth & development ; microbiology ; Pest Control, Biological ; methods ; Plant Diseases ; microbiology ; Plant Roots ; microbiology ; Plants, Medicinal ; growth & development ; microbiology ; Rhizoctonia ; pathogenicity ; Soil Microbiology ; Trichoderma ; physiology