Plants resistance to pathogens attack can be induced by biological control methods including fungal extracts. The main purpose of this study was to obtain chromatographic images of biochemical compounds responsible for biological quality of strawberry intracellular medium, of various culture filtrates of pathogenic or antagonistic fungi and to compare the aspects of interactions between them. Previous research showed that microorganisms such as bacteria and fungi from soil and especially plant rhizosphere can influence plant growth or improve resistance to pathogens. Systemic induced resistance can be also acquired by vaccination with fungal extracts with elicitor effect. Four extracts were obtained from pathogenic isolates of species Botrytis cinerea and from antagonistic species Trichoderma viride, Trichoderma harzianum and Penicillium chrysogenum cultivated on potato-dextrose medium. Fungal extracts E1, E2, E3 and E4, as well as citosolic extract from strawberry plants cultivar Marmolada were migrated and individual paper chromatograms were obtained for each. The chromatograms of interactions resulted by simultaneous migration of biochemical compounds of strawberry plants and fungal extracts. This is a new approach of paper chromatography we decided to use for the study of plant-fungi interactions, motivated by the biochemical nature of these  interactions. The method has the advantage to provide images of the distribution of biochemical compounds from both plant and fungal extracts and of the nature of their interactions. The aspect of contact zones between plant and fungal extracts were different for extracts as a function of the group of fungi involved. E1, E2 and E4 that contained elicitors of  immunity from Botrytis isolates induced similar convex zones in plant with low individual variations but E3 from antagonistic isolates of Trichoderma and Penicillium induced a concave margin of plant chromatogram. The method is very usefull for rapid assessment of the answer of plant to a fungal extract and helpfull as a qualiative preliminary test for selecting biological control agents with role in immunologic stimulation of plant.

plant resistance; fungal extract; strawberry; Botrytis cinerea; paper chromatography

Presentation: oral