In order to mitigate the occurrence and damage of cowpea anthracnose and reduce the chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design and statisti...In order to mitigate the occurrence and damage of cowpea anthracnose and reduce the chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design and statistical analysis were conducted to study the control effect of biopesticide chitosan, biochemical compound Prochloraz-Chitosan and chemical pesticides difenoconazole and thifluzamide by field efficacy trials. The results showed that under serious occurrence of anthracnose in autumn greenhouse cowpea, when the 2% chJtosan AS （2 250 g/hm^2）, 46% Prochloraz-Chitosan EW （450 g/hm^2）, 10% difenoconazole WG （900 g/hm^2, CK） or 24% thifluzamide SC （360 ml/hm^2） were applied three times with an interval of 5-8 d, the control efficiency on day 7, 14 and 20 reached 83%, 78% and 73%, respectively. No significant difference was found in control efficiency among the four kinds of agents. These four kinds of agents, especially chitosan and Prochloraz-Chitosan, could be used as ideal agents for controlling anthracnose, as well as for modern agricultural demonstration zones, pollution-free agricultural products, green agricultural products and organic agricultural products,thereby meeting the develop- ment needs of ＇modern agriculture, green agriculture, organic agriculture and ecological agriculture.展开更多
Colletotrichum gloeosporioides is the causal agent of anthracnose disease in fruits and vegetables, representing a global problem. The use of biocontrol agents has proved effective against fungal diseases in a wide va...Colletotrichum gloeosporioides is the causal agent of anthracnose disease in fruits and vegetables, representing a global problem. The use of biocontrol agents has proved effective against fungal diseases in a wide variety of products. In this work, the antifungal activity of Wickerhamomyces anomalus against C. gloeosporioides isolated from contaminated avocados was evaluated. The antagonism and volatile compound inhibition were measured on Petri dishes. In the mixed cultures, the mycelia damage was observed by scanning electron microscope （SEM）. Chitinase and glucanase production by the antagonism was quantified by the reducing sugars method, and biofilm formation was evaluated with 1% crystal violet. The yeast W. anomalus could reduce the growth of C. gloeosporioides up to 65% by direct antagonism and 10% by volatile compounds. The antagonist did not allow the conidia germination and mycelia growth in any of the tested formulations. SEM showed mycelial damage caused by W. anomalus. The antagonist showed adhesion to the mycelium by a polysaccharide biofilm. The presence of mycelium stimulated the hydrolytic enzyme production with the maximal activity of 21.4 U/mg for chitinases at 24 h and 10 U/mg for glucanases at 60 h. These results showed that W. anomalus used together different mechanisms to express its antifungal activity against C. gloeosporioides. This study might be the first report for this phytopathogen isolated from avocado fruits, which could represent an opportunity to establish biocontrol of diseases for this agricultural product.展开更多
基金Supported by Circular of the Ministry of Agriculture on Approval of the First Batch of the National Demonstration Zones for Modern Agriculture(NJF[2010]22)Fundamental Research Funds for the Central Universities(XDJK2015C057,SWU114046)~~
文摘In order to mitigate the occurrence and damage of cowpea anthracnose and reduce the chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design and statistical analysis were conducted to study the control effect of biopesticide chitosan, biochemical compound Prochloraz-Chitosan and chemical pesticides difenoconazole and thifluzamide by field efficacy trials. The results showed that under serious occurrence of anthracnose in autumn greenhouse cowpea, when the 2% chJtosan AS （2 250 g/hm^2）, 46% Prochloraz-Chitosan EW （450 g/hm^2）, 10% difenoconazole WG （900 g/hm^2, CK） or 24% thifluzamide SC （360 ml/hm^2） were applied three times with an interval of 5-8 d, the control efficiency on day 7, 14 and 20 reached 83%, 78% and 73%, respectively. No significant difference was found in control efficiency among the four kinds of agents. These four kinds of agents, especially chitosan and Prochloraz-Chitosan, could be used as ideal agents for controlling anthracnose, as well as for modern agricultural demonstration zones, pollution-free agricultural products, green agricultural products and organic agricultural products,thereby meeting the develop- ment needs of ＇modern agriculture, green agriculture, organic agriculture and ecological agriculture.
文摘Colletotrichum gloeosporioides is the causal agent of anthracnose disease in fruits and vegetables, representing a global problem. The use of biocontrol agents has proved effective against fungal diseases in a wide variety of products. In this work, the antifungal activity of Wickerhamomyces anomalus against C. gloeosporioides isolated from contaminated avocados was evaluated. The antagonism and volatile compound inhibition were measured on Petri dishes. In the mixed cultures, the mycelia damage was observed by scanning electron microscope （SEM）. Chitinase and glucanase production by the antagonism was quantified by the reducing sugars method, and biofilm formation was evaluated with 1% crystal violet. The yeast W. anomalus could reduce the growth of C. gloeosporioides up to 65% by direct antagonism and 10% by volatile compounds. The antagonist did not allow the conidia germination and mycelia growth in any of the tested formulations. SEM showed mycelial damage caused by W. anomalus. The antagonist showed adhesion to the mycelium by a polysaccharide biofilm. The presence of mycelium stimulated the hydrolytic enzyme production with the maximal activity of 21.4 U/mg for chitinases at 24 h and 10 U/mg for glucanases at 60 h. These results showed that W. anomalus used together different mechanisms to express its antifungal activity against C. gloeosporioides. This study might be the first report for this phytopathogen isolated from avocado fruits, which could represent an opportunity to establish biocontrol of diseases for this agricultural product.
