ЗАЩИТА РАСТЕНИЙ DIVERSITY OF PHYTOPATHOGENIC BACTERIA OF GENUS XANTHOMONAS ISOLATED FROM POACEAE PLANTS IN RUSSIA M.S. Egorova1, E.S. Mazurin1, V.A. Polityko2, A.N. Ignatov3 1All-Russian Plant Quarantine Center Pogranichnaya, 32, Bykovo, Ramenskoe, Moscow region, Russia, 140150 2Russian Research Institute of Phytopathology (VNIIF) Bolshie Vyazemy, Moscow reg., Russia, 143050 3Department of botany, plant physiology and agrobiotechnology Peoples’ Friendship University of Russia Miklukho-Maklaya str., 8/2, Moscow, Russia, 117198 We reviewed the published data on a composition of plant pathogenic bacteria of the genus Xanthomonas damaging plant of family Poaceae (cereals) in Russia together with our new data obtained from surveys of cereal seeds from different regions of Russia. <...> We assayed the xanthomonads on cereal seeds from different regions and have identified for the first time pathogens similar to species X. hortorum, X. campestris, X. cynarae, X. pisi, and X. gardeneri, which have not been reported yet on the cereal crops. <...> Key words: Cereals, bacterial leaf streak, bacterial leaf blight of rice, black chaff, Xanthomonas translucens, Xanthomonas oryzae, Xanthomonas arboricola. <...> Cereals are main crops of agricultural production in Russia. <...> However, the main grain crops (wheat, barley, rye, rice, oats) are affected by a number of pathogens that can significantly reduce the yield. <...> Some authors described rapid spreading of bacterial diseases of cereals in recent years [1; 2]. <...> They have underlined several main reasons of the increasing of bacterial diseases severity including: — Emergence of new aggressive species and biotypes (races) of phytopathogenic bacteria; — Climate changes; — Inappropriate agrotechnology of growing, harvesting and storage of seeds; — Lack of accurate diagnosis of pathogens [1]. <...> Plant diseases caused by phytopathogenic bacteria of the genus Xanthomonas are among the most common and associated with serious economic losses at different regions 47 Вестник РУДН, серия Агрономия и животноводство, 2014, № 4 of Russia, since they affect the most important cereals, cruciferous, solanaceous, legumes, and other crops. <...> Bacterial diseases caused by xanthomonads on the cereal crops are among the most harmful diseases transmitted by seeds <...>