Milium effusum L. (Poaceae) in Eastern Asia differs strongly in ITS sequence from conspecific plants in other parts of the species range

Violetta KOTSERUBA1, Victoria SHNEYER1, Nina PROBATOVA2, Andreas HOUBEN3 & Frank BLATTNER3
1 Komarov Botanical Institute RAS, Saint-Petersburg, Russia
2 Institute of Biology and Soil Science, Vladivostok, Russia
3 Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany

Milium effusum L. (Poaceae, Poeae) is a perennial widespread woodland species distributed across Europa, Asia, in the northeastern parts of North America throughout much of the Holarctic ecozone with disjunction in the west of North America. Tetraploid (2n = 28) chromosome number was constant in all the samples investigated. Plants from different parts of the range are morphologicaly uniform. Allozyme variation analyses found the species to be variable but no clear geographic patterns in the distribution of alleles were found among samples from Europe and the Altai Mountains (Tyler 2002). The nuclear ribosomal DNA internal transcribed spacer region (ITS) was found to be informative in the phylogenetic studies at the species and intraspecies level. We investigated the region ITS1-5.8S-ITS2 in 4 species of Milium. Milium effusum was represented by samples from throughout most of its distribution range - from different regions of Europe, Caucasus, Siberia, Middle Asia, Eastern Asia, and North America. All sequences formed two distinct clades with the samples of M. effusum from Eastern Asia (Kamchatka, Kuril Islands, Primorsky krai, Japan, China) clustering into a separate clade than the rest of M. effusum samples which formed the second clade together with M. transcaucasicum and M. schmidtianum (all from the section Milium). The pairwise sequence divergence between two clades is 0,054. It is close to that between M. effusum and M. vernale, the species from the other section of the genus (0,060). Further research should be done to elucidate if plants from East Asia represent a separate taxon, subspecies or even cryptic species. The research was supported by DAAD, DFG and RFBR grants.

2012 Organizing Committee