SodininkyStĖ ir darŽininkyStĖ 27(3)

SODININKYSTĖ IR DARŽININKYSTĖ. SCIENTIFIC ARTICLES. 2008. 27(3).Genetic studies of apple scab resistance and application of molecularbiology methods in apple tree breedingD. Baniulis, D. Gelvonauskienė, B. Gelvonauskis, R. Rugienius, V. Bendokas,V. StanysSummaryApple scab (V. inaequalis) is one of the most important diseases of apple. The resistanceto apple scab is determined by quantitative or qualitative traits. Application of qualitativeresistance traits in traditional apple-tree breeding is a complicated task, therefore genesdetermining quantitative resistance traits have been predominantly used in breeding scabresistant cultivars. Fourteen resistance genes have been identified and characterized. Vf genehas been the most popular in apple breeding programmes. However, a genetic adaptivity ofV. inaequalis has resulted in emergence of the pathogen strains that overcome the monogenicresistance. This fact stresses the importance of development of breeding strategy based oncombination of multiple resistance genes. An effective “pyramidization” strategy requiresnew apple scab resistance gene identification and integration into breeding programmes.Introduction of multiple genes into single apple tree cultivar is a complicated taskto achieve using traditional breeding methods. Application of modern molecular biologymethods provides tools for resistance gene localization on genetic maps and developmentof molecular markers used for an efficient gene donor selection and analysisof inheritance of resistance traits. In addition, achievements of apple scab resistancebreeding programme at the Lithuanian Institute of Horticulture established since 1957and genetic studies of resistance traits that have been initiated in 1987 are reviewed.Key words: apple tree, Malus sp., scab, Venturia inaequalis, resistance genes, molecularmarkers, breeding.75