Increasing the efficiency of potato breeding through marker assisted selection - general thoughts. Molecular markers for late blight resistance - when applied for breeders?

摘要

In potato breeding, specific and often complex resistances need to be developed, at the same time maintaining high levels of quality and culinary characteristics. The progress in the genetics of disease resistance in potato and current technologies of genotyping and marker assisted selection (MAS) are reviewed to determine the parameters that limit the efficiency potato breeding using molecular markers. Selection in potato for resistance to late blight caused by Phytophthora infestans is highlighted as an example. Maps, genes and markers for resistance are identified. Single genes and quantitative trait loci for race-specific and race non-specific resistance are also identified. Marker technologies based on polymerase chain reaction and DNA hybridization have been developed that are far more efficient than the first-generation technologies. The most important parameters required for economical MAS included having a clear idea of the traits to be selected for, to use proven, reliable markers, to have in place a robust system for the collection and management of DNA samples, and to use technologies whose total cost is below or equal to the cost of the conventional methods. Using MAS, the breeder will obtain more precise information and field labour can be saved thereby intensifying the breeding process. The implementation of the new technology could lead to even closer collaboration of breeders and scientists. Possible disadvantages include the relative increase of laboratory and computer work within the breeding programme, and higher costs during the implementation phase of the new technology.