Biosystematic study of the Cyanus triumfetti group in Central Europe.

Multivariate morphometrics and an assessment of genetic diversity obtained using amplified fragment length polymorphism (AFLP) were used to determine the variability of the polymorphic group Cyanus triumfetti in Central Europe. The ploidy level of the populations studied was also determined; all individuals from the C. triumfetti group were diploid (2n ~ 2x ~ 22) and all those of the related C. montanus group were tetraploid (2n ~ 4x ~ 44). A multivariate morphometric study of 71 populations revealed that three species from the C. triumfetti group occur in Central Europe, namely ‘Cyanus axillaris’, C. strictus and C. dominii. Three subspecies are recognized within the latter species, namely C. dominii subsp. dominii, C. dominii subsp. slovenicus and C. dominii subsp. sokolensis. Morphological characters of leaves are the best features for delimiting these taxa; a shift in characters caused by cultivation did not affect the value of key characters and differences among the taxa remained. AFLP analysis of 38 populations from the C. triumfetti group and two from the C. montanus group revealed a contrasting pattern of genetic variation that was related to the geographic distribution of the populations rather than the morphological variation in the C. triumfetti group. The AFLP data revealed the following three genetically differentiated and allopatric groups: (i) C. triumfetti s.s. and C. montanus from the Western Alps, (ii) ‘C. axillaris’ from Austria and the Czech Republic (except the Carpathians) and (iii) ‘C. axillaris’, C. strictus and C. dominii from the Western Carpathians and Pannonia. The striking genetic gap between the Austrian-Czech and the W Carpathian-Pannonia groups and the high genetic diversity and weak genetic differentiation within the latter group are discussed in the light of potential glacial refuges, postglacial migration routes and/or the probability of hybridization events occurring during the evolutionary history of this group. An identification key for the taxa of the C. triumfetti group in Central Europe is presented.