Characterization of plant material obtained by in vitro androgenesis and in situ parthenogenesis in apple

The production of doubled haploids offers new possibilities for genetic studies and breeding. In apple Malus × domestica Borkh., double haploid and thus homozygous material was obtained by in vitro androgenesis and in situ parthenogenesis followed by embryo or cotyledon culture. This paper describes a comprehensive evaluation of material induced concerning ploidy level, zygosity state using isozyme and SSR analysis, tree morphology, flower, and fruit quality, respectively. The use of homozygous lines in apple will be discussed in view of the efficiency of the induction process and the fertility of the plant material. The application in running breeding programmes is not a realistic approach at present, while single lines with selected characteristics can already be used for pre-breeding experiments and detailed genetic studies.