Study of the vegetative structure of Agrimonia eupatoria L. in the in vivo and in vitro plants

The study of vegetative structures of plants is effective in the development of biology and is one of the research methods in the field of taxonomy. Agrimonia eupatoria L. is a valuable medicinal plant of the Rosaceae. Due to weak germination and time-consuming growth in the natural habitat, tissue culture is a good method to accelerate the propagation of this plant. In the present study, the anatomical structure of vegetative organs in the in vivo plants was compared with the in vitro plants. Roots, stems, leaves, and petioles of plants in both groups were sampled and fixed in alcohol-glycerine and manual cutting was performed. The samples were stained with Carmen/Methylene blue. The results showed that the general structures in both samples are similar but in the regenerated plants, the density of protective tissues was lower than the in vivo plants (number of layers of collenchyma tissue was less and there was no sclerenchyma). Vascular bundles in the stem, leaves, and petiole of both groups were seen as bicollateral. The number of palisade parenchyma layers and spongy parenchyma layers in the leaves of both groups was similar. The macle crystal structures were observed in the parenchyma of stem and petiole in both groups, but its number was lower in regenerated plants. On the stem and leaves of this plant, there were numerous trichomes that the numbers of trichomes in the regenerated plants were less than natural plants.