부산대학교 도서관

The aim of this work was an in vitro testing of the antifungal biological activity of two natural aromatic products, concrete and resinoid, derived from three species of Nicotiana: N. tabacum L. – oriental type, variety "Plovdiv 7"; N. alata Link & Otto – two genotypes, and N. rustica L. Test-pathogens (microscopic fungi) were isolated from plant tissues with typical symptoms of diseases and from epiphytic microflora on fine cut tobacco, by classical microbiological methods. Morphological characteristics of the colonies and microscopic diagnosis were made on each fungal isolate. The in vitro antifungal tests were performed by the diffusion method on 72-96 h cultures of the pathogen, according to the size of the inhibited zone (mm). Isolated fungal pathogens were related to the phylum Ascomycota, genera Stemphylium, Alternaria, Sclerotinia, Fusarium, Colletotrichum, and Aspergillus. Different antifungal effects of tobacco aromatic products were found, depending on the type of the product, the species of tobacco and the species of the pathogen. Tobacco resinoids exhibited a more pronounced effect, compared with the respective concretes. The activity against the phytopathogens of the genera Stemphyllium and Alternaria was the highest. Pathogen species belonging to the genera Sclerotinia, Colletotrichum and Aspergillus were effectively inhibited by the aromatic products of N. tabacum and N. alata. An antifungal effect on the isolates of genus Fusarium was found only for tobacco resinoids. The results from the study are promising for the use of natural aromatic products from Nicotiana species as a basis for the development of biological products with antifungal action. [ABSTRACT FROM AUTHOR]