Genetic linkage maps for apomictic Hieracium species

Apomixis in plants generates clonal progeny with a maternal genotype through asexual seed formation. Hieracium subgenus Pilosella (Asteraceae) contains polyploid, highly heterozygous apomictic and sexual species, and Shirasawa et al. develop a collection of expressed SSR markers in order to construct linkage maps for Hieracium species. Previously identified apomixis loci that are responsible for two independent components of apomixis, LOSS OF APOMEIOSIS (LOA) and LOSS OF PARTHENOGENESIS (LOP), are successfully assigned to linkage groups. These maps will support the cloning of controlling genes at LOA and LOP loci in Hieracium and should assist with identification of quantitative loci that affect apomixis expressivity.