[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 iso...[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.展开更多
Dry heat treatment has been identifie as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber(Cladosporium cucumerinum that causes scab...Dry heat treatment has been identifie as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber(Cladosporium cucumerinum that causes scabs, Ascochyta citrullina that results in gummy stem blight,and Colletotrichum orbiculare that induces anthracnose) could be effectively eradicated from cucumber seeds by dry heat treatment. In vitro growth of these three pathogens was inhibited by dry heat treatment at 70 °C for 40 min. These pathogens were inactivated after exposing infected seeds to 70 °C dry heat for at least 90 min. Seed infection was significant y reduced by exposing the seeds to 70 °C dry heat for at least 40 min. Seed moisture content and germination were slightly reduced after 70 °C heat treatment for 40–120 min. Seed vigor remained at a high level after dry heat treatment at 70 °C for 90 min. In conclusion, 70 °C dry heat treatment for 90 min was determined to be the optimal method for eradication of C. cucumerinum, Didymella bryoniae, and C. orbiculare from cucumber seeds.展开更多
Orbicular rocks refer to a group of rocks having orbicular structure named by von Buch in 1802. They have been found in more than one hundred localities in thirty countries. Approximately 43% of the orbicular rocks, h...Orbicular rocks refer to a group of rocks having orbicular structure named by von Buch in 1802. They have been found in more than one hundred localities in thirty countries. Approximately 43% of the orbicular rocks, having been reported in literature, are granitic rocks; 30% dioritic; 15% gabbroic; 8% schistic and chromititic. However, the ultramafic orbiculite has not yet been reported. In 1984, a kind of orbicular rock on展开更多
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]
文摘[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 the earmarked fund for the Science and Technology Innovation Program of the Chinese Academy of Agricultural Science(CAAS-ASTIP-IVFCAAS)the National Key Technology Support Program(2012BAD19B06)funded by the Key Laboratory of Horticultural Crops Genetic Improvement,Ministry of Agriculture in China
文摘Dry heat treatment has been identifie as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber(Cladosporium cucumerinum that causes scabs, Ascochyta citrullina that results in gummy stem blight,and Colletotrichum orbiculare that induces anthracnose) could be effectively eradicated from cucumber seeds by dry heat treatment. In vitro growth of these three pathogens was inhibited by dry heat treatment at 70 °C for 40 min. These pathogens were inactivated after exposing infected seeds to 70 °C dry heat for at least 90 min. Seed infection was significant y reduced by exposing the seeds to 70 °C dry heat for at least 40 min. Seed moisture content and germination were slightly reduced after 70 °C heat treatment for 40–120 min. Seed vigor remained at a high level after dry heat treatment at 70 °C for 90 min. In conclusion, 70 °C dry heat treatment for 90 min was determined to be the optimal method for eradication of C. cucumerinum, Didymella bryoniae, and C. orbiculare from cucumber seeds.
基金Project supported by Science Foundation of the State Education Commission, PRC.
文摘Orbicular rocks refer to a group of rocks having orbicular structure named by von Buch in 1802. They have been found in more than one hundred localities in thirty countries. Approximately 43% of the orbicular rocks, having been reported in literature, are granitic rocks; 30% dioritic; 15% gabbroic; 8% schistic and chromititic. However, the ultramafic orbiculite has not yet been reported. In 1984, a kind of orbicular rock on
