Formation of the phytopathogenic mycobiome of seeds of sunflower hybrids in the conditions of the Сentral Forest-Steppe of Ukraine

Abstract

A high level of contamination of the seeds of sunflower plants with phytopathogenic micromycetes can lead to a significant decrease in the yield of this valuable crop, a decrease in the oiliness of the seeds, a deterioration of its sowing qualities, and an increase in the quantitative and qualitative losses of the crop during storage. As a result of the vital activity of microorganisms on plant seeds, both the sowing qualities of the seeds (germination energy, germination, viability and productivity) and food quality indicators are significantly reduced (the fatty acid composition changes, oiliness decreases and the acid number of the oil increases). Therefore, the goal of our work was to determine the number and spectrum of phytopathogenic micromycetes in the mycobiome of sunflower seeds in the conditions of the Central Forest-Steppe of Ukraine. According to the research results, it was found that the biological properties of Dushko and Oliver hybrids, in the conditions of traditional and organic cultivation technologies, can both suppress and stimulate the number of micromycetes in the seed mycobiome. The formation of the number of phytopathogenic micromycetes in the mycobiome of the seeds of Dushko and Oliver hybrids under the organic technology of growing sunflower plants was at the level of traditional technology and ranged from 5.0 to 5.5 thousand CFU/g in the fruit shell, and from 2.1 to 2.6 thousand CFU/g of dry seeds. The seed microbiome of the investigated sunflower hybrids is represented by micromycetes with phytopathogenic properties (A. alternata and F. oxysporum) and species capable of causing seed mold (Penicillium, Aspergillus), the frequency of which varies from 5 to 65%. Phytopathogenic fungi inhabiting the seeds of sunflower plants are a powerful factor in the biological pollution of agroecosystems and are capable of significantly reducing seed quality and nutritional quality indicators of seed production of sunflower plants.