Aiming to enhance the amount of biologically active substance a new research of the modification of annual drug plants by biotechnological methods has been started. The diploid plant sorts: Viola tricolor, Perilla frutescens, Centaurea cyanus, Calendula officinalis, Angelica archangelica, Trigonella foenum-graecum have been selected in order to create more productive polyploid forms.[...].
