Morphological and genetic variability of chosen Mentha species
The objects of the studies were 4 species of mint: Mentha aquatica L., peppermint (Mentha x piperita L.), spearmint (Mentha spicata var. crispa L.) and a variety of pineapple mint (Mentha suaveolens Ehrh.) - ‘Variegata’. Phenotype differences between the studied species were determined on the basis of morphometric measurements of the length of the longest sprout, the plant diameter, the number of sprouts as well as length and width of the leaf. To determine the genotype differences, an ISSR-PCR technique was used. The ISSR reactions were carried out using 20 microsatellite primers and their products were separated in 2% agarose gel. It was found that the studied genotypes of mint differ significantly from one another, both in relation to the analyzed morphologic and genetic features. For genotypes characterized in the experiment, a number of mono- and polymorphic products were amplified and among them there were a series of species specific ISSR products. Phylogenetic similarity of the compared species varied from 53.3% between M. x piperita and M. aquatica to 82.2% between M. suaveolens ‘Variegata’ and Mentha spicata var. crispa.