向日葵黃萎病生防木霉菌的篩選及其生防機制的研究.pdf

1、 Screening of Antagonistic Trichoderma to Sunflower Yellow Wilt and Study on the Biocontrol Mechanisms Abstract Verticillium wilt is a serious vascular diease caused by a soil borne pathogen V erticillium dahliae Kleb. i

2、n sunflower. Aiming at production of sunflower still exist the difficulty of the disease control, and little control technology research of sunflower Verticillium wilt at home and abroad. Trichoderma as a universal bioco

3、ntrol fungus has attracted a lot of attention. In this study, the experiment is focus on screening of Antagonistic Trichoderma to V erticillium dahliae and study on the biocontrol mechanisms. The results showed as follow

4、s: 1. In this experiment, 80 strains of Trichoderma isolated from potato and sunflower stalks and roots collected from different locations which more than 200 samples. Through the plate screening method , the potted expe

5、riment and the field text, the results indicate that the strain XM-7 that possed stronger potential ability to biocontrol were selected through the antagonistic tests against V erticillium dahliae. In the field experimen

6、t, the strain PT-15 also showed significant control effect achieved 80.28%, which is better than chemicals flusilazole, there were no significant difference with strain XM-7, but this strain performance instability in th

7、e potted experiment and confrontation test. The results showed that, in contrast, XM-7 was relatively stable, combined with the potted experiment and the field text, the strain XM-7 possed stronger potential ability to b

8、iocontrol. 2. By means of molecular biology and morphology methods, isolates XM-7 was identified as Trichoderma citrinoviride. 3. Trichoderma citrinoviride XM-7 biological characteristics research results showed that the

9、 PDA culture medium was the best medium for the XM-7. The optimum mycelium growth temperature of XM-7 was 30℃, and the optimum spore temperature was 25℃, and pH5~6 was the optimum pH for XM-7 mycelium growth, and pH7 was

10、 the most favorable for the conidiation . Soluble starch and mannose is optimum carbon source for XM-7 mycelial growth, glucose and sucrose is the carbon source for XM-7 sporulation and the optimum nitrogen source was be