关键词: 钩状木霉, 辣椒疫霉, 生物防治, 定殖, 根际土壤

Abstract: Trichoderma spp. is an important biocontrol fungus resource widely distributed in nature. The colonization ability of biocontrol bacteria in host rhizosphere and its tissues is an important index to evaluate its potential of biocontrol against plant diseases. In this study, a fungiplant interaction system including Trichoderma hamatum labeled with green fluorescence protein (GFP), pepper plant and pepper Phytophthora blight fungi (Phytophthora capsici) were built. The inoculation with conidium solution of T. hamatum was carried by pouring into pepper root. Combined dualculture assay and pot experiment in greenhouse, the colonization ability of T. hamatum in pepper plants and rhizosphere soil, and its biological control against P. capsici was investigated. The results showed that T. hamatum could be colonized in root, stem, and leaf of pepper and its rhizosphere soil. In the rhizosphere soil of pepper, T. hamatum showed a dynamic colonization process. The colonization of T. hamatum increased slowly from 1 to 25 d after inoculation, and reached the highest value (700×107 conidia·g-1) gradually at 33 d after inoculation, then decreased gradually, showing a dynamic process of increasing first and then decreasing. It was revealed that T. hamatum has biological control effect on pepper Phytophthora Blight during the colonization process of T. hamatum in pepper plant and rhizosphere, the control effect is 5333%. In conclusion, T. hamatum could effectively prevent the occurrence of pepper Phytophthora Blight in field, as a beneficial fungus in microorganism of pepper rhizosphere. The present research provided a theoretical basis and effective way for the biological control of pepper Phytophthora Blight.

Key words: Trichoderma hamatum, Phytophthora capsici, biological control, colonization, rhizosphere