Genetic and morphological diversity of Finnish tansy (Tanacetum vulgare L., Asteraceae)

Morphological and genetical differences of twenty Finnish tansy (Tanacetum vulgare) genotypes were studied. The genotypes were distinguishable by morphology, and number of flower heads, which correlated positively with height of the plant and height of the corymb. The mean nuclear DNA content in the leaves of tissue-cultured tansy plantlets was 8.86 pg, and variation between genotypes was 27%. The genotypes were also distinguishable on the basis of their RAPD patterns. The RAPD and morphological data were subjected to analysis of principal components, according to which the genotypes were separated into two main groups. Group I included 7 genotypes from southern Finland and 2 genotypes from the eastern lake district. They started to flower later, had more flower heads and nodes per stem, and the corymb was longer than in the other genotypes that originated in the western and central part of Finland and formed group II. Our data are supported by previous studies and suggest that group I may represent native tansy populations in Finland, whereas group II may represent tansy genotypes that have been transported to other parts of Finland through agriculture and attempts of domestication.