Biocontrol Mechanisms And Utilization Research Of Biocontrolling Strain MT-06

Biological control is a very useful method to control plant diseases because it is benefit to environmental protection, ecological balance and human health. The fungal strain MT-06 isolated from strawberry anthracnose disease tissue was tested to be a potential biocontrol strain against the disease. The characteristics and biocontrol mechanism along with the field control efficiency of strain MT-06 was studied.1. The test of antimicrobial spectrum shows that the strain MT-06 could inhibit many kinds of pathogens in vitro. The biological characteristics of this strain was determined by measuring the influence of different medium, temperature, pH and light treatment on colony growth and spore production of MT-06. The results showed that The PDA and PSA media were most favorable to its colony growth, while Czapek medium was most favorable to its conidial production. The optimal temperature ranged from 28℃to 35℃for its colony growth and the optimal initial pH of culture media was 5. The strain could grow in either dark or light, but lighting was beneficial for vegetative growth and sporulation. Besides, the sequences of ITS andβ-tubulin which obtained by PCR was used to identify MT-06 along with morphologic observation. MT-06 was identified as Talaromyces flavus based on morphologic observation and both ITS andβ-tubulin sequence.2. Two fluorescence-expression vectors were constructed. The vector pGFP was transformed into MT-06 and Magnaporthe grisea, while the vector pRFP was transformed into Colletotrichum gloeosporioides via Agrobacterium tumefaciens-mediated transformation (ATMT). After several screening and verification, it was confirmed that GFP and RFP genes had been inserted in the genome of fungus. But the fluorescence in MT-06 and C. gloeosporioides was hardly to see. The confrontation of MT-06 and C. gloeosporioides on slide showed that the hyphal of MT-06 could grow coiling on C. gloeosporioides.3. The fermentation of MT-06 was collected to study the inhibition efficiency on 10 pathogens. The result showed that the fermentation solution could inhibit many kinds of pathogens in vitro and was tolerant to high-temperature and high-pressures to a certain degree. It seemed that MT-06 could produce excretion substances to inhibit the growth of those pathogens.4. Field experiments in the breeding period showed that MT-06 could inhibit strawberry anthracnose and strawberry powdery mildew, and the field control efficiency was better or equal to chemical agents. Besides, MT-06 was good for reducing exsciccation rate caused by anthracnose and increasing seedling. And the result of study on colonization showed that MT-06 could colonize well on strawberry with the colonization of 100%.