Genetic diversity amongst landraces of rye (Secale cereale L.) from northern Europe.

Genetic variation and diversity were estimated for three improved varieties and 18 landraces of Secale cereale, originating from the northern Europe. This material was compared with eight improved varieties and 16 landraces from Sweden, which were analysed before. The analysis used starch gel electrophoresis with the enzymes ACO, GPI, MDH, PGD and PGM and resulted in one fixed locus and seven polymorphic loci. Most of the genetic diversity was found within the accessions and it was very small between accessions. The results show that the landraces from Germany and Norway have a low genetic variation compared to the other landraces in this study. This can possibly be explained with a small original sample size of some accessions. However, in the dendrogram these accessions are well separated. The landraces from Sweden and Finland showed a high genetic variation, which is almost the same for all these accessions. In the dendrogram all of the Finnish landraces and 11 of the Swedish ones were grouped together with a very small diversity index; they can almost be considered as part of the same accession. This is probably due to the fact that a high number of Finnish immigrants arrived in Sweden during the 17th century bringing their own rye material. The early Finnish rye landraces may have the same original source. The data also show that landraces as well as improved varieties have a high heterozygosity but they are separated in the dendrogram into different clusters. The currently used varieties show a large genetic distance variation, different from that in the landraces.