Species compositions of root rot agents of spring barley

We studied the ratio of fungi genera in the affected root system of spring barley, the composition of pathogenic and comorbid mycobiota, which affected barley at different ontogeny stages. We discovered that the main root rot agents were Fusarium spp., Bipolaris spp., Rhizoctonia spp., Pythium spp., Alternaria spp., and the bacterium of Pseudomonas genera. In our research, 50.65% of Fusarium genera were taken at a sprouting stage from the affected root system, 54.25% were taken at tillering stage, and 56.25% were taken at milky-wax ripeness. The next abundant was B. sorokiniana fungus  (20.6% of which were taken at sprouting stage, 18.4% at tillering stage, and 18.45% were taken at milky-wax ripeness. Less frequent were the representatives of Rhizoctonia genera – 19.45, 16.15, and 13.2% respectively. We suggested that while studying the pathogenic characteristics of root rot agents of spring barley, more attention need to be paid to their impact on the laboratory germination ability of seeds, the degree of the disease progression, biometric indices and plants persistence. Keywords: Spring barley; Root Rot; Species composition of the agents; Correlation of fungi genera; Pathogenic mycobiota; Phases of plants ontogeny   References Ashley, R.O., Mullen, M.M., Eriksmoen, E., Schmidt, B., Barondeau, D., Duerre, D. & Eraas, K.  (2000). Diagnosis and management of root disease in dryland wheat in southwest North Dakota. Dickinson Research Extension Center Annual Report. Available from: https://www.ag.ndsu.edu/archive/dickinso/research/2000/agron00p.htm Bilai, V.I.  (1977). Fuzarii. Kiev, Naukova Dumka  (in Russian). Bilai, V.I.  (1982). Metody eksperimentalnoj mikologii. Kiev. Naukova Dumka  (in Russian). Chulkina, V.A., Tabakayev, V.N. & Pahotnyuk, V.E.  (1974). Osobennosti zarazheniya semyan yarovoj pshenicy i yachmenya fitopatogennymi gribami v razlichnyh ekologo-geograficheskih zonah Zapadnoj Sibiri. Borba s vreditelyami i boleznyami selskohozyajstvennyh kultur, Nauchno-tehnicheskij byulleten, 12, 3–11.  (in Russian). Khohriakov, M.K.  (1974). Metodicheskie ukazaniya po eksperimentalnomu izucheniyu fitopatogennyh gribov. Leningrad. Nauka  (in Russian). Korshunova, A.F., Chumakov, A.F. & Shchecochihina, R.I.  (1976). Zashita pshenicy ot kornevyh gnilej. Leningrad. Kolos  (in Russian). Mirchink, T.G.  (1976). Pochvennaya mikologiya. Moscow. Moscow State University  (in Russian). Naumov, N.A.  (1937). Metody mikologicheskih i fitopatologicheskih issledovani. Moscow. Selhozizdat  (in Russian). Nelson, P.E., Toussoun, T.A., Marasas, W.F.O.  (1983). Fusarium species. University Park. The Pennsylvania State University Press. Pidoplichko, N.M.  (1977–1978). Griby – parazity kulturnyh rastenij. Vol. I-III. Kiev. Naukova dumka.  (in Russian). Tepliakov, V.I. & Tepliakova, O.I.  (2003). Bolezni yarovoj pshenicy v Zapadnoj Sibiri. Zashita i karantin rastenij, 1, 17–18.  (in Russian).