V. Chesnokov2, V.A. Polityko3, E.V. Matveeva3, A.A. Oraevskiy4, N.W. Schaad5 2 N.I. Vavilov All-Russia Research and Development Institute of Plant Growing, RAAS, St.Petersburg 190000, Russia 3 All-Russia Research and Development Institute of Phytopathology, RAAS, Moscow province, Odintsovo region, Bol’shye Vyazemy settlement 143050, Russia 1 Center “Bioengineering” of RAS, Moscow 117312, Russia e-mail: an.ignatov@gmail.com 5 Foreign Disease – Weed Science Research Unit of the United States Department of Agriculture, 21702-5023 MD, Fort Detrick, USA Received June 24, 2010 S u m m a r y 4 State Agrarian University – MTAA named after K.A. Timiryazev, Moscow 127550, Russia The authors estimated the apple varieties and hybrid gene pool created during 1970-2009 years in All-Russian Scientific Research Institute of Orchard Culture the content of sugars, organic acids, ascorbic acid and P-active substances. <...> The prospect of apple varieties selection with improved biochemical composition of fruit was shown. <...> Cruciferous plants (the family Brassicaceae) are susceptible to many phytopathogens, the most harmful of which is the bacterium Xanthomonas campestris Pam. (Dow.). <...> X. сampestris variants cause diseases with different symptoms - vascular bacteriosis (X. campestris pv. campestris - Xcc) and leaf blotch (X. campestris pv. raphani - Xcr). <...> Physiological races are detected by reaction of cultivars possessing race-specific resistance genes (1, 2). <...> Three genetically close diploid species of the genus Brassica (B. rapa, B. nigra and B. oleracea) are distinct in type of resistance to bacterioses caused by X. campestris. <...> In forms carrying B-genome, this feature is determined by the gene Rxa1 (previously designated as Rb) (1), in A-genome - Rxa4, and in C-genome - Rxa3 encoding the most common type of resistance (2). <...> Along with it, there are allelic variants of three major loci and other types of resistance to X. campestris (3, 4). <...> Breeding for pathogen resistance is limited by a small number of available donors (especially in B. rapa and B. napus), while the existence of more than 9 pathogen races (4) complicates interpretation of literature <...>