APOMIXIS AND HYBRIDITY IN HYPERICUM-PERFORATUM

A review is presented of breeding peculiarities in Hypericum perforatu m L. and their consequences. This species is a tetraploid hybrid (2n=4 x=32) which is assumed to be allopolyploid. It is a facultative apomic t with apospory and pseudogamy. Original results of chromosome number variation amongst H. perforatum regenerants are presented, and their s eed 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 seve ral authors, are discussed.