Bacterial and fungal interactions in the tuberculosis pathology of common ash in Ukraine

Abstract

The present study is focused on the recent epiphytotic dieback of many forest species both in Ukraine and other countries of the world. In the research on the phenomenon, there has been little concern regarding phytopathogenic bacteria, which have high reproduction energy and can penetrate the plant and cause a pathological process as vital obligates. One of the most common and harmful diseases of common ash in Ukraine is tuberculosis. The causative agent of the disease is the phytopathogenic bacterium Pseudomonas syringae subsp. savastanoi (ex Smith 1908) Janse 1982. This species affects both trunks, branches and shoots, and inflorescences of a common ash. The bacteria Pseudomonas sp., Pseudomonas fluorescens Mig., Pseudomonas syringae Van., Erwinia herbicola Eh., Xanthomonas sp. were isolated from tuberculous samples as a concomitant myco- and microbiota and micromycetes Cladosporium cladosporioides (Fresen.) G.A. de Vries., Alternaria botrytis (Preuss) Woudenb. & Crous, taxon Mycelia sterilia (dark) and Mycelia sterilia (orange), Fusarium heterosporum Lin., Fusarium sp., Cylindrocarpon didymum (Harting) Wollenw, etc. The mechanism of systemic relationships of the components of myco- and microbiota of tuberculous pathology of the common ash in the regulation (self-regulation) of pathogenicity and aggressiveness of vital obligates has been investigated. The study is focused on the prospects and expediency of using the antagonistic properties of myco- and microorganisms and biological products based on them for the prevention and protection of tree plantations from bacterial pathogens. It is shown that the pathology of the common ash is a multifaceted phenomenon with interrelated processes of an infectious and non-infectious nature. Plant diseases caused by pathogens have been increasing in number and severity over the last few decades in response to increases in human mobility, climate change, land-use intensification, urbanization and the creation of new habitat conditions (Anderson et al. 2004, Aukema et al. 2010, Meentemeyer et al. 2012). The need to distinguish between the etiology and pathogenesis of this negative phenomenon is indicated, that is, not to mix the factors that lead to the weakening of the ordinary ash (factors catalyzing the disease) and the factors that cause its epiphytotic dieback.