Taxonomy Of Penicillium Link In Ningxia And Screening Of Antagonist Penicillium Against To Rhizoctonia Solani

Penicillium was a kind of the important fungi in nature. It always lead to some plant diseases, and it was also a kind of potential antagonistic fungus for plant disease. There have been more than 250 species in the world since Link (1809) introduced the generic name Penicillium, and China has reported about 110 species by now. The taxonomy of Penicillium has not been researched in Ningxia Hui Automonous Region. So make clearly the species and distribution of Penicillium and screen with some kinds of biocontrol effect, was of great significance to enrich the Penicillium diversity, explore resources of antagonistic fungi in Rhizoctonia solani, and promote the prevention and control of the plant diseases.During of this dissertations’research,449 soil samples and 63 plant diseases samples were collected systematicly from 93 downtowns of 22 counties of Ningxia Hui Automonous Region. And made a taxonomic identification by combined classical morphological taxology and the methods in amplification and sequencing of ITS1-5.8S-ITS2 gene and rRNA BenA gene protein fragment. Then selected 30 Penicillium strains with Rhizoctonia solani to make inhibition method, and screened the better antagonistic Penicillium. The main conclusions were as follows.1. Screened 457 strains of Penicillium and got 59 species Penicillium, Which of them include 49 kown species in China,46 new records in Ningxia,2 new records in China,1 new species and 7 unidentified species. All species of morphological features were described and photos were provided.2. The new species was named Penicillium ningxiaensis. New record species were listed as follows:Penicillium pasqualense 、Penicillium polonicum 。3. Developed a new culture medium YDA compared with common culture medium CYA, which of the isolation effect was 2.5 times.4. Screened one strain named as P19 could inhibit the mycelium growth of Rhizoctonia solani with the inhibitory effect of 58.5%. Through the study on its action mechanism, find the appearance of the wall was found to be crooked and deformed, protoplast condensation and dissolution, the mycelium is dissolved and so on. It could also contained antibacterial substances in P19 to damage cell wall of Rhizoctonia solani, then dissolved the hyphae of protoplasts, limit the growth of Rhizoctonia solani.5. By test on stability of fermentation, The result showed that P19 strain has stable thermal stability and pH stability, which could got the highest antibacterial activity while 20℃, treatment of 10min and PH=3, processing 2h. So P19 strain could be developed as the potential biocontrol agent.