XVI International Botanical Congess

P. major L. and P. intermedia Gilib. are two closely related taxa, formerly recognised as subspecies of P. major. They differ for their ecology and for several morphological characters, like the number of seeds per capsule. Where the taxa are found sympatric hybrids can be found. Using RAPDs we showed that the plants form two distinct groups, each representing one taxon. We now need to develop several types of markers to answer questions arising from this result. We need to know how frequent hybridisation takes place and what the fate of the hybrids in mixed populations is. For this microsatellites would be ideal. Using non-recombining markers we could study the biogeography of the two widespread taxa and test how much gene flow occurs between them. In the first instance chloroplast and nuclear rDNA sequence variation will be tested.