Fyzická mapa chromozómu 4AL pšenice a poziční klonování genu ovlivňujícího výnos.

Bread wheat (Triticum aestivum L.) is one of the most important crops worldwide. Wheat provides basic food for 35% of the world population and is grown in a wide range of environments, mainly in temperate zone. Its importance can be compared only with rice or maize. Fast growing human population dramatically increases importance on food produc-tion including wheat production. Breeding of highly yielding wheat cultivars resistant to biotic and abiotic stresses is the main challenge for current breeding programs. Wheat genome is composed of three related diploid genomes (A, B and D) and contains more than 80 % of repetitive sequences. This great genome complexity makes breeding, molecular markers development, marker assisted selection (MAS) and wheat genome sequencing very complicated. Reduction of the complexity by the flow sorting of chromosomes or chromosome arms greatly facilitates marker development and mapping. The sorting also provides sufficient quantity of high molecular weight DNA for survey sequencing and BAC library construction. Development of large numbers of chromosome specific markers allows construction of high density maps creating an ideal base for map based cloning of agronomically important genes. The aim of the present Ph.D. thesis was to construct a sequencing-ready 4A chromo-some-specific physical map and high density radiation hybrid map to use them for map satu-ration and cloning of the powdery mildew-resistance gene QPm-tut-4A, rust resistance gene (Yr51) and yield related gene Qyi-4A-bga.