Apomixis in Taraxacum : an embryological and genetic study = Apomixie in Taraxacum : een embryologische en genetische studie

Apomixis is asexual plant reproduction through seeds that are produced with no prior genome reduction or fertilisation. The use of apomixis holds enormous potential for future plant breeding and production. The outcome of the research described in this thesis suggests that the genetic basis for apomixis in Taraxacum (dandelions) comprises three major dominant genes whose timely expression may be influenced by modifier genes. Its also suggests that genome interactions effect successful establishment of apomixis in polyploid hybrids of sexual x apomictic dandelions. The work consisted of cytogenetic and embryological studies performed at the Laboratory of Genetics, Wageningen University, and the analysis of inheritance of apomixis in sexual x apomict crossings performed at the Netherlands Institute of Ecology, Centre for Terrestrial Ecology, (NIOO-CTO), Heteren, the Netherlands. A theoretical model for the Taraxacum type of apomixis is described. As a conclusion, we discuss several aspects of the evolution of apomixis in Taraxacum which serve to explain why Taraxacum is a very successful genus.