Screening, Identification And Application Of Antagonistic Microbes To Colletotrichum Capsici

Pepper Anthracnose caused by Colletotrichum spp is an economically important diseases of pepper cultivars, which can occur on leaves, stems, and both pre-and post-harvest fruits and lead to pepper fruit disease rate from10%to50%. Anthracnose disease is also one of the major economic constraints to pepper production in china. Therefore, screening antagonistic microbes to Colletotrichum spp is the main study target for pepper anthracnose control.Antagonistic microbes were isolated from soil collected from Huangguoshu Waterfalls in Guizhou province, Lang Mountain and Zhangjiajie National Forest Park in Hunan province, and it was found that one strain named No.18could obviously inhibit growth of Colletotrichum capsici and its spores germination. After treatment with No.18strain fermentation filtrate diluted by5times,10times and20times, Colletotrichum capsici conidiospore germination inhibition rates were74.9%,60.4%and50.7%respectively. This study further showed that fermentation liquid had no significant effect on seed germination of pepper.Based on morphological characteristics, physiological and biochemical test and16S rDNA sequence analysis, No.18strain was identified to Streptomyces flaveus. In vitro inoculation test and field experiments showed that No.18strain had an significant control effect on pepper anthracnose. When we treated pepper fruit with No.18strain fermentation filtrate diluted by50times, there was decrease(64.76%) in disease rate of pepper fruit and the control effect was75.74%. The experiments showed that No.18strain is a potential antagonist to control pepper anthracnose and can be used as a biocontrol agent.