| The pathogen of eggplant Verticillum wilt was isolated and identified from the eggplant soil in suburb of Yaan, Sichuan. Trichoderma strains were isolated and identified from eggplant soil. Biocontrol mechanism of representative strains of different species of Trichoderma was studied. Changes of amounts of bacteria, actinomyces and fungi in eggplant soil and changes of Trichoderma species and amounts at rhizosphere and non-rhizosphere were investigated. Some explorations were made to improve the quality of Trichoderma agent before conservation and some explorations were also made to improve the quality of Trichoderma agent after conservation. The results were as follows:1. The pathogen of eggplant Verticillum wilt was Verticillum dahliae at suburb of Yaan, Sichuan. There were six Trichoderma species and one Gliocladium species in the soil at the area. They were T. citrinoviride, T. hamatum, T. viride, T. longibrachiatum, T.konigii, T. harzianum and Gliocladium virens. Among them T. hamatum was the dominant species.2. The antagonistic mechanism of Trichoderma on Verticillum dahliae were suppressing the growth of Verticillum dahliae, coiling and distorting hypha of Verticillum dahliae. The function of non-volatility metabolite was the most important one in the function of metabolite. Among the six Trichoderma species and the one Gliocladium species, the suppression of 8218 on Verticillum dahliae was the strongest one, the suppression rate of which was 88.1%, and the suppression of 815 on Verticillum dahliae was the weakest one, the suppression rate of which was only 19.4%.3. The maize gruel liquid culture medium which was cultured two days were inoculated to solid culture medium which were made of wheat bran. When the water content of solid medium was 60% and the cultural humidity was 90%, Trichoderma agent reached its best quality which was 1.7#106cfu/g. After two months conservation, the quality of trichoderma agent under the conservation condition of 0℃ was generally better than that of 28℃. After two months conservation, when the water content of solid medium was 60%, the cultural humidity was 90% and the conservation condition was 0℃, trichoderma agent reached its best quality which was 0.3#105cfu/g, and when the water content of solid medium was 50%, the cultural humidity was 80% and the conservation condition was 0℃, trichoderma agent reached its best livability which was 15.4%.4. At different depth in eggplant soil, the species and amounts of microorganism changed with time: amount of bacteria, actinomyces and fungi reached their maximum at June, which were 10#106cfu/g, 9#106cfu/g and 0.7#106cfu/g at the depth of0-5cm and 15.6×106cfu/g, 5.2×106cfu/g and 0.2×106cfu/g at the depth of 5-10cm respectively. But the proportions of bacteria, actinomyces and fungi to microorganism reached their maximum at May, July and June respectively. Between the depth of 0-5cm and 5-10cm, the amount of bacteria at the depth of 5-10 was more than that at 0-5cm, while the amount of actinomyces and fungi at the depth of 0-5cm were both more than that at 5-10cm. There were more Trichoderma species and amounts in the eggplant soil introduced with T. citrinoviride agent than the eggplant soil not introduced with T. citrinoviride agent. In the soil not introduced with T. citrinoviride agent, the dominate Trichoderma species was T. hamatum both at rhizosphere and non-rhizosphere. ?In the soil introduced with T. citrinoviride agent, the dominate Trichoderma species at rhizosphere were T. hamatum and T. citrinoviride while the dominate Trichoderma species at non-rhizosphere was T. hamatum. T. citrinoviride had become the dominate Trichoderma species after eggplant soil was introduced with T. citrinoviride agent.5. The function that the T. citrinoviride agent can promote the growth of eggplant was observed. The growth-promoting function mainly was that eggplant treated with agent grew higher, blossomed more flowers and yielded more fruits than eggplant untreated. |
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