摘要
[ Objective] The paper was to study biological characteristics of Fusarium oxysporum f. sp. niveum in watermelon cultivated in plastic greenhouse in Hainan Province of China and to determine indoor toxicity of fungicides. [ Method] Effects of various factors on mycelial growth and spore germination were stud- ied, and the lethal temperature of spores and indoor toxicity of fungicides were also determined. [Result] The fungal mycelium had a better growth rate on water- melon juice medium than the others. The optimum temperature for mycelial growth and spore germination were 28 ℃ and 30 ℃, and the optimum pH values were 7 - 8 and 7 - 9, respectively. Light-dark alternation was conducive for mycelial growth. The lethal temperature of spore was 60 ℃ for 5 min. The fungal mycelium grew better while taking fructose and glucose as carbon sources and yeast extract and peptone as nitrogen sources. Toxicity determination showed that 50% pro- chloraz-manganese chloride complex WP had the greatest inhibition effect on mycelial growth, with the ECso value of 0.730 9 μg/mL; followed by 32.5% benzoic azoxystrobin SC, 30% benzoylate· propieanazol EC, 10% difenoconazole WG, 25% bromothalonil · carbendazim WP and 25% bromothalonil WP, with the ECso values from 1.884 7μg/mL to 8. 161 0μg/mL. [Conclusion] The study provided basic data for field control against F. oxysporum f. sp. niveum on watermelon cultivated in plastic greenhouse in Hainan Province.
[ Objective] The paper was to study biological characteristics of Fusarium oxysporum f. sp. niveum in watermelon cultivated in plastic greenhouse in Hainan Province of China and to determine indoor toxicity of fungicides. [ Method] Effects of various factors on mycelial growth and spore germination were stud- ied, and the lethal temperature of spores and indoor toxicity of fungicides were also determined. [Result] The fungal mycelium had a better growth rate on water- melon juice medium than the others. The optimum temperature for mycelial growth and spore germination were 28 ℃ and 30 ℃, and the optimum pH values were 7 - 8 and 7 - 9, respectively. Light-dark alternation was conducive for mycelial growth. The lethal temperature of spore was 60 ℃ for 5 min. The fungal mycelium grew better while taking fructose and glucose as carbon sources and yeast extract and peptone as nitrogen sources. Toxicity determination showed that 50% pro- chloraz-manganese chloride complex WP had the greatest inhibition effect on mycelial growth, with the ECso value of 0.730 9 μg/mL; followed by 32.5% benzoic azoxystrobin SC, 30% benzoylate· propieanazol EC, 10% difenoconazole WG, 25% bromothalonil · carbendazim WP and 25% bromothalonil WP, with the ECso values from 1.884 7μg/mL to 8. 161 0μg/mL. [Conclusion] The study provided basic data for field control against F. oxysporum f. sp. niveum on watermelon cultivated in plastic greenhouse in Hainan Province.
基金
Supported by Epidemic Monitoring and Control Program of Pests and Diseasesin Tropical Crops in 2013 by Ministry of Agriculture(Issued Document Number:NBK[2013]No.28)
