The Isolation And Fungistasis Of Endophytes From Pyracantha Fortuneana

Endophytic fungi are fungi that inhabited in the rhizome, leaves and fruits of healthy plants and having no pathological stress or obvious infection to its hosts. There demonstrates positive symbiosis between the endophytic fungi and the hosts. The host plants could provide the endophytic fungi with photosynthetic products and necessary minerals, and thee secondary metabolites of the endophytic fungi could facilitate the growth of the host plants directly or indirectly, thus to improve the hosts'resistance to biological or non-biological stresses.In the research, 15 kinds of endophytic fungus strains were isolated from the stems, leaves and fruits of Pyracantha fortuneana. And 4 strains marked as S1–S4 were isolated from the stems, 8 strains marked as L1–L8 were isolated from the leaves, 3 strains marked as F1–F3 were isolated from the fruits. Using 9 kinds of pathogenic fungi, such as Alternaria alternata, Glomerella cingulata, Gibberella zeae, etc, as the targets, the antifungal activity of the metabolites of the endophytic fungi from Pyracantha fortuneana was investigated, and screened out S4 strain with higher antifungal activity.15 isolated endophytic fungi strains were cultivated in liquid medium respectively. The total of culture including the mycelia and cultural liquid were extracted with acetone after desiccating, triturating and the Fungistasis of the extracts were determined. The toxicity equation between the S4 extracts and pathogenic fungi was established and a qualitative chemical analysis of the S4 extracts was conducted. The results showed that strains which have the antifungal activities accounted for 86.67% in the 15 endophytic fungi. The antifungal activity of S4 to nine kinds of plant pathogenic fungi was notable, the inhibition rate was all up to 50%, and the highest was 97.14%. The acetone extracts of S4 showed a broad antifungal spectrum. The acetone extracts of S1, S3, L1 strains had the higher inhibition rate. The preliminary test of the chemical components showed that the S4 extracts might contain reducing sugar, organic acid, falconoid, lactones and coumarin.The molecular identification of endophytic fungus S4 in Pyracantha fortuneana was carried. The extracts genomic 18S rDNA identification and PCR amplification was conducted by the CTAB method. After purification and DNA sequencing, the preliminary study showed that S4 may belong to Diaporthe.The antifungal activity of S4 still needs to be further investigated.