Discrimination between sexual recombination and apomixis/automixis in a Rubus plant breeding programme

Nineteen offspring plants from an inter-specific Rubus plant breeding programme were DNA fingerprinted to investigate whether they had arisen by hybridisation or by apomixis/automixis. Additional data were provided also on morphology, fruiting ability, chromosome number, and pollen germination. Whereas hybridisation apparently had taken place in most cases, automixis (i.e., the fusion and subsequent parthenogenetic development of two egg nuclei in a reduced embryo sac) was also suggested in some plants showing reduced vigour and fruiting ability. Their DNA fingerprints exhibited no paternal influence, but some maternal bands were also missing, suggesting that meiosis had taken place prior to the parthenogenetic egg development. Although common in parthenogenetic animal groups, this is the first molecular evidence of automixis in plants.