Species composition of phytopathogenic micromycetes in seeds of cultural plants varieties

Abstract

It is analyzed that the formation of pathogenic microbiome cultural plant is due to the interaction of populations of phytopathogenic micromycetes with plants of the variety as a biotic ecological factor in the formation of phytopathogenic background in agrophytocenoses of varieties cultural plant. The seeds of such promising varieties of cultural plant as soybeans (Kent and Suzirya), buckwheat (Son and Sophia), thistle (Riches) and yellow mustard (Forge) for micromycetes were analyzed. We carried out the analysis of seeds types of such cultural plant as soybean, buckwheat, thistle, mustard yellow on the location micromycetes and identified phytopathogenic fungi: Alternaria alternate Fr., Fusarium oxysporum Schleht, Cladosporium herbarum Lket Gray, Botrytis cinerea Pers. ex Fr., Ascochyta fagopyri Bres., Alternaria tenuissima (Kunze) Wiltshire, Aspergillus P. Micheliex Haller, Pénicillium Link., Mucor Micheliex F. It was determined that the species composition of phytopathogenic micromycetes in soybean and thistle seeds s is much more diverse compared with buckwheat and mustard yellow seeds. Among the identified micromycetes there are species with varying degrees of parasitism: obligate and facultative saprotrophs and parasites. To assess the typicality of the species and determine its position in the structure of dominance in the agrocenosis of cultivated plants, the criterion of the frequency of occurrence of the species was used. Fungi of genera Alternaria alternate, Fusarium oxysporumare characterized by different frequency of occurrence (11–30%). The seeds of Suzirya soybean variety and Son and Sophia buckwheat varieties are intensively inhabited by fungi of the genus Pénicillium (60–90%). We determined the indicator of similarity species composition of micromycetes withdrawn from seeds types of cultural plants by Jacquard similarity coefficient. It is established that seeds of soybeans and thistle as well as the seeds of thistle and yellow mustard are characterized with high level of micromycetes similarity (indicator of similarity — 75 and 66.7% respectively). At the same time, seeds of buckwheat and thistle as well as buckwheat and mustard yellow were characterized with low level of micromycetes similarity – 12.5 and 22.2%, respectively. The analyzed indicators provide an opportunity to evaluate seeds types of cultural plant in order to avoid ecological risks and biological pollution of agrocoenoses during sowing and cultivation of crops of different varieties.