A population of Potentilla nivea at Latnjajaure in northern Swedish Lapland was studied in order to establish the potential for apomixis as well as the actual proportion of apomictic offspring produced after intra- and interspecific crossings, respectively. The sympatric species P. crantzii was used for reciprocal interspecific hybridization. Offspring from all crosses were germinated and grown and used for morphometric analyses as well as molecular paternity determination. The potential for apomixis, given as the average number of unreduced megagametophytes produced per flower, is ca. 25% in P. nivea. The average Seed:ovule-ratio after interspecific pollination is 0.15 and the offspring show no sign of being hybrids. Rather their morphology and genotypes indicate that they are produced by apomixis. Fifteen percent seed set is within the limit for the potential number of apomictic offspring that can be produced. The average Seed:ovule-ratio after conspecific mating is 0.40. There is evidence of sexual activity, but to what extent Potentilla nivea at Latnjajaure reproduces sexually when it interbreeds normally is not known yet. The AFLP-data is currently being analyzed. The hypothesis is that sexuality plays an important role in the reproduction of Potentilla nivea and that apomixis is mainly induced by illegitimate mating.

Key words: hybridization, level of apomixis, paternity analysis, Potentilla crantzii, Potentilla nivea