title: Genetic analyses of the host-pathogen system Turnip yellows virus (TuYV)-rapeseed (Brassica napus L.) and development of molecular markers for TuYV-resistance.
abstract: The aphid transmitted Turnip yellows virus (TuYV) has become a serious pathogen in many rapeseed (Brassica napus L.) growing areas. Three-years' field trials were carried out to get detailed information on the genetics of TuYV resistance derived from the resynthesised B. napus line 'R54' and to develop closely linked markers. F(1) plants and segregating doubled-haploid (DH) populations derived from crosses to susceptible cultivars were analysed using artificial inoculation with virus-bearing aphids, followed by DAS-ELISA. Assuming a threshold of E (405) = 0.1 in ELISA carried out in December, the results led to the conclusion that pre-winter inhibition of TuYV is inherited in a monogenic dominant manner. However, the virus titre in most resistant lines increased during the growing period, indicating that the resistance is incomplete and that the level of the virus titre is influenced by environmental factors. Bulked-segregant marker analysis for this resistance locus identified two closely linked SSR markers along with six closely linked and three co-segregating AFLP markers. Two AFLP markers were converted into co-dominant STS markers, facilitating efficient marker-based selection for TuYV resistance. Effective markers are particularly valuable with respect to breeding for TuYV resistance, because artificial inoculation procedures using virus-bearing aphids are extremely difficult to integrate into practical rapeseed breeding programs.
authors.affiliation: Institute for Resistance Research and Stress Tolerance, Federal Research Centre for Cultivated Plants, Julius Kühn-Institute, Erwin-Baur-Strasse 27, Quedlinburg, Germany.
authors.forename: Monique
authors.initials: M
authors.lastname: Juergens
authors.forename: Claudia
authors.initials: C
authors.lastname: Paetsch
authors.forename: Ilona
authors.initials: I
authors.lastname: Krämer
authors.forename: Marc
authors.initials: M
authors.lastname: Zahn
authors.forename: Frank
authors.initials: F
authors.lastname: Rabenstein
authors.forename: Jörg
authors.initials: J
authors.lastname: Schondelmaier
authors.forename: Edgar
authors.initials: E
authors.lastname: Schliephake
authors.forename: Rod
authors.initials: R
authors.lastname: Snowdon
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Friedt
authors.forename: Frank
authors.initials: F
authors.lastname: Ordon
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D029741:Brassica rapa / Q000235:genetics* / Q000276:immunology* / Q000821:virology; D032461:Chromosomes, Plant; D005819:Genetic Markers; D052679:Luteoviridae; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology*
chemical_list: D005819:Genetic Markers