Fungal pathogen of asparagus stem blight was isolated. No significant genetic difference was detected among the three strains with 492 bp long ITS1-5.8S-ITS2 sequence. It was then identified through colony growth, con...Fungal pathogen of asparagus stem blight was isolated. No significant genetic difference was detected among the three strains with 492 bp long ITS1-5.8S-ITS2 sequence. It was then identified through colony growth, conidia morphology, and molecular characterization. The physiological response to oxidation and osmosis stress, and virulence to Asparagus officinalis L. were analyzed. The results showed that the pathogen causing asparagus stem blight for A. officinalis L. in Jiangxi Province is Phomopsis asparagri (Sacc.) Bubák. Under pure culture conditions, the conidia were oval-shaped (α-type), with colorless single spore and single nucleus, containing 0-2 oil balls. Its vegetative growth rate was higher when cultured on 0.2 × potato dextrose agar (0.2 × PDA) medium than that on oatmeal agar (OA) medium. However, the pycnidia appeared earlier on OA medium than on 0.2 earlier PDA medium. The vegetative growth rate was depressed under oxidation (H2O2) or osmosis (NaCl) stress conditions, and totally inhibited under 7 mmol/L H2O2 or 2.4 mol/L NaCl. All the strains caused typical pathogenic symptoms to Asparagus officinalis L. at 7 days-post-inoculation (dpi) with conidia.展开更多
[Objective]The study was to evaluate the indoor toxicity and field efficacy of five Strobilurins fungicides including pyraclostrobin 250 g/L EC,azoxystrobin 250 g/L SC,kresoxim-methyl 50%WG,picoxystrobin 22.5%SC and t...[Objective]The study was to evaluate the indoor toxicity and field efficacy of five Strobilurins fungicides including pyraclostrobin 250 g/L EC,azoxystrobin 250 g/L SC,kresoxim-methyl 50%WG,picoxystrobin 22.5%SC and trifloxystrobin 50%WG against Phomopsis asparagi(Sacc.)Bubak,and to screen out effective fungicides.[Method]The toxicity was tested by mycelial growth rate method.The field trials were carried out by routine spraying method.[Result]The indoor toxicities successively were pyraclostrobin>kresoxim-methyl>picoxystrobin>trifloxystrobin>azoxystrobin.The EC50 values were 6.1029,52.5591,83.8257,129.8616 and 252.1214 mg/L,respectively,all significantly higher than that of benzimidazole fungicide carbendazim(753.3650 mg/L).The field efficacies successively were pyraclostrobin>kresoxim-methyl≥picoxystrobin≥azoxystrobin≥trifloxystrobin.The control effects were 81.20%,77.95%,74.80%,71.69%and 68.54%,respectively,all significantly higher than that of benzimidazole fungicide carbendazim(48.27%).[Conclusion]The five Strobilurins fungicides all have good toxicity and field efficacy against P.asparagi.展开更多
文摘Fungal pathogen of asparagus stem blight was isolated. No significant genetic difference was detected among the three strains with 492 bp long ITS1-5.8S-ITS2 sequence. It was then identified through colony growth, conidia morphology, and molecular characterization. The physiological response to oxidation and osmosis stress, and virulence to Asparagus officinalis L. were analyzed. The results showed that the pathogen causing asparagus stem blight for A. officinalis L. in Jiangxi Province is Phomopsis asparagri (Sacc.) Bubák. Under pure culture conditions, the conidia were oval-shaped (α-type), with colorless single spore and single nucleus, containing 0-2 oil balls. Its vegetative growth rate was higher when cultured on 0.2 × potato dextrose agar (0.2 × PDA) medium than that on oatmeal agar (OA) medium. However, the pycnidia appeared earlier on OA medium than on 0.2 earlier PDA medium. The vegetative growth rate was depressed under oxidation (H2O2) or osmosis (NaCl) stress conditions, and totally inhibited under 7 mmol/L H2O2 or 2.4 mol/L NaCl. All the strains caused typical pathogenic symptoms to Asparagus officinalis L. at 7 days-post-inoculation (dpi) with conidia.
基金Supported by Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences"Key Technology for Green Prevention and Control of Diseases and Insect Pests of Major Crops"(CXGC2018E19).
文摘[Objective]The study was to evaluate the indoor toxicity and field efficacy of five Strobilurins fungicides including pyraclostrobin 250 g/L EC,azoxystrobin 250 g/L SC,kresoxim-methyl 50%WG,picoxystrobin 22.5%SC and trifloxystrobin 50%WG against Phomopsis asparagi(Sacc.)Bubak,and to screen out effective fungicides.[Method]The toxicity was tested by mycelial growth rate method.The field trials were carried out by routine spraying method.[Result]The indoor toxicities successively were pyraclostrobin>kresoxim-methyl>picoxystrobin>trifloxystrobin>azoxystrobin.The EC50 values were 6.1029,52.5591,83.8257,129.8616 and 252.1214 mg/L,respectively,all significantly higher than that of benzimidazole fungicide carbendazim(753.3650 mg/L).The field efficacies successively were pyraclostrobin>kresoxim-methyl≥picoxystrobin≥azoxystrobin≥trifloxystrobin.The control effects were 81.20%,77.95%,74.80%,71.69%and 68.54%,respectively,all significantly higher than that of benzimidazole fungicide carbendazim(48.27%).[Conclusion]The five Strobilurins fungicides all have good toxicity and field efficacy against P.asparagi.
