Influence of Exometabolites of Different Varieties of Cultural Plants on the Growth and Development of Pathogenic Micromycetes Bipolaris Sorokiniana and Alternaria Alternata

Abstract

Objective. To establish the influence of exometabolites of winter wheat plants of Podolianka, Natalka, Skagen, Mulan varieties and oats of Skarb Ukrainy, Svitanok, Tembr varieties on the growth and development of Bipolaris sorokiniana micromycete, as well as the influence of onion of Tkachenkivska, Mavka, Veselka, Liubchyk, Variah, Harmonia varieties on the growth and development of the micromycete Alternaria alternata. Methods. Mycological, phytopathological, phytoimmunological. Results. Two hundred isolates of pathogenic micromycetes were isolated from the seeds of the studied crops of different varieties. The most common microbiota were: Bipolaris sorokiniana, Alternaria alternata, Alternaria tenuissima, Alternaria infectoria, Stemphylium vesicarium, Curvularia inaequalis. The highest incidence on wheat and oat seeds (over 80 %) was reported for B. sorokiniana, on onion seeds — for A. alternata. It was found that exometabolites of plants of different varieties can both inhibit and stimulate the rate of radial growth of mycelium of B. sorokiniana and A. alternata. It was proved that exometabolites of plants of wheat, oats, onion can significantly affect the reproductive capacity of the studied micromycetes, which reduced the number of spores per 1 cm2 of colony area almost 1.2–2.5 times compared to the control. This indicates that exometabolites of plants are characterized by fungicidal properties, which are due to a complex of biologically active substances that can inhibit the intensity of sporulation of B. sorokiniana and A. alternate. Conclusion. The antifungal property of root exometabolites of plants of the studied varieties significantly depends on the genotype of the variety. Therefore, an important timely task is to identify environmentally stable and flexible varieties that are characterized by group resistance to pathogens of fungal origin, as well as the search for mechanisms of action of fungicidal natural origin.