Apomixis and hybridity in Hypericum perforatum

A review is presented of breeding peculiarities in Hypericum perforatum L. and their consequences. This species is a tetraploid hybrid (2n=4x=32) which is assumed to be allopolyploid. It is a facultative apomict with apospory and pseudogamy. Original results of chromosome number variation amongst H. perforatum regenerants are presented, and their seed offspring were studied. The results suggest that genetic diversity occurs in this taxon resulting in great phenotypic variation. Various records of natural and artificial hybridization, as published by several authors, are discussed.