摘要
[Objective] This paper was aimed to study the biological characteristics of Colletotrichum orbiculare（Berk.et Mont.） Arx, and accomplish the preliminary screening the test of fungicides. [Method]The pathogen was isolated from the infected leaves of watermelon collected from greenhouse in Hainan Province. The biological characteristics of C. orbiculare and indoor toxicity of fungicides were studied. [Results] The mycelium grew fastest on the medium with leaf extract of watermelon. The optimum temperature for mycelial growth and spore germination was 28 and 30 ℃, and the optimum pH was 7-9 and 6-8, respectively. The continuous darkness condition was most suitable for mycelial growth. The lethal temperature of spore was 55 ℃ water bath for 10 min in water bath. The suitable carbon sources were maltose, L-arabinose and glucose, and the suitable nitrogen sources were yeast extract, beef extract and peptone. In the indoor toxicity determination, 32.5% Benzoic azoxystrobin SC, 50% Dichlorotetrakis WP and 10% Difenoconazole WG showed better inhibition effects against the mycelial growth of C. orbiculare, with the EC50 values of 0.018 0, 0.060 2 and 0.471 5 μg/ml, respectively. [Conclusion]The research provided theoretical basis for the control of watermelon anthracnose in watermelon fields.
[Objective] This paper was aimed to study the biological characteristics of Colletotrichum orbiculare（Berk.et Mont.） Arx, and accomplish the preliminary screening the test of fungicides. [Method]The pathogen was isolated from the infected leaves of watermelon collected from greenhouse in Hainan Province. The biological characteristics of C. orbiculare and indoor toxicity of fungicides were studied. [Results] The mycelium grew fastest on the medium with leaf extract of watermelon. The optimum temperature for mycelial growth and spore germination was 28 and 30 ℃, and the optimum pH was 7-9 and 6-8, respectively. The continuous darkness condition was most suitable for mycelial growth. The lethal temperature of spore was 55 ℃ water bath for 10 min in water bath. The suitable carbon sources were maltose, L-arabinose and glucose, and the suitable nitrogen sources were yeast extract, beef extract and peptone. In the indoor toxicity determination, 32.5% Benzoic azoxystrobin SC, 50% Dichlorotetrakis WP and 10% Difenoconazole WG showed better inhibition effects against the mycelial growth of C. orbiculare, with the EC50 values of 0.018 0, 0.060 2 and 0.471 5 μg/ml, respectively. [Conclusion]The research provided theoretical basis for the control of watermelon anthracnose in watermelon fields.
基金
Supported by Scientific Funds Project of Hainan Province[(QCY(2009)71]
Local Standards of Hainan Province in 2011 "Technical Regulation of Greenhouse Watermelon Production"Project[QZJJ(2011)11]
