Tuberculosis Pathology of Fraxinus Excelsior L. in Ukraine: Symptomatology, Etiology, Pathogenesis

Abstract

Given the forestry, the ecological and economic value of forests with the participation of Fraxinus excelsior and taking into account the intensive deterioration of their phytosanitary status in modern conditions, a comprehensive study of symptoms, causes, and pathogenesis of ash tuberculosis with further development of effective protection measures, including using biological products based on Bacillus sp. and other myco- and microorganisms, is a particularly relevant area of research. The aim of the research is to identify negative abiotic and biotic factors in the pathology of F. excelsior. In the process of research general scientific and special research methods were used (microbiological, mycological, phytopathological, entomological, and silvicultural-ecological methods). It is emphasized that the pathology of the common ash is a multifaceted phenomenon with interrelated processes of infectious and non-infectious nature, which in recent years has led to epiphytic dieback and now has a tendency to increase. It has been established that tuberculosis of F. excelsior is the most common and harmful disease within the study region and causes more economic than environmental damage. Bacteria of the genera Pseudomonas sp., Erwinia sp., and Xanthomonas sp., as well as micromycetes, which mainly take the place of the concomitant mycobiota. There are five stages (phases) of the development of tuberculosis pathology, which differ significantly in symptoms. The species composition of harmful insects has been identified. It is shown that hydrothermal stress is a catalyst for the epiphytic dieback of common ash. Direct dependence of the spread of tuberculosis on the share of ash in the stands of different age groups was revealed. In the study area, tuberculosis reaches epiphytotics on F. excelsior, especially at a young age. The expediency of distinguishing the causes and pathological processes associated with ash tuberculosis is indicated, so as not to confuse the disease-catalyzing factors and the factors that lead to the complete degradation of ash stands

Bacterial Diseases of Bioenergy Woody Plants in Ukraine

“…), Lelliottia nimipressuralis (Carter 1945) These diseases are registered within the forest areas of Ukraine on many species of forest woody plants, in particular, the silver birch (Betula pendula Roth.) [5], common oak (Quercus robur L.) [7], common ash (Fraxinus excelsior L.) [10,11], silver fir (Abies alba Mill.) [12], and others.…”

“…It is strong, heavy, hard, elastic, viscous, flexible, machined, hard to prick, slightly grooved and cracked, and well-polished, but not resistant to rot. Therefore, the growing of common ash is known to be associated with significant difficulties, since ash is more often affected by infectious diseases than other species [10,11]. Forestry practitioners and scientists are alarmed by the deterioration of sanitary conditions and the dieback of Fraxinus excelsior in more than 30 European countries in recent years.…”

“…This trend was first registered in Lithuania and north-eastern Poland in the early 1990s [20]. The disease then spread north to Latvia and Estonia [21]; Germany and Sweden [22]; the Czech Republic, Slovakia, Finland, and Denmark [23]; Austria [24]; Hungary, Slovenia, and Norway [25]; France [26]; Italy and Greece [27]; Belgium [28]; the Netherlands, England, and Ireland [10]; and Ukraine [11]. Researchers have isolated a significant species and the diversity of myco-and microorganisms.…”

“…The latest confirmed studies in Ukraine and the world indicate that the phytopathogenic bacterium Pseudomonas savastanoi (ex Smith 1908), found by Gardan et al 1992, is the causative agent of tuberculosis of F. excelsior. In pathology, it is accompanied by certain micromycetes and other components of the microbiota [11].…”