Propagation of two selected species of the genus Pieris D. Don.

anglais. This work evaluates the results of propagation experiments of Mountain Pieris (Pieris floribunda /Pursh/Benth. & Hook.) and Japanese Pieris (Pieris japonica /Thunb./ D. Don) we carried out in the Arboretum Mlyňany SAS. The material was sampled from the two exemplars of these species growing in the Arboretum. The methods used were auto-vegetative propagation by cuttings and in vitro micropropagation. The response of the studied woody plant species varied according to the species and the method used. In Japanese Pieris, better results were achieved by vegetative propagation by cuttings

in Mountain Pieris, much more effective propagation method was micropropagation. We also studied the effect of climatic variables on the physiological conditions of the parent plants, and the overall rooting success in primary cultures obtained by micropropagation of Mountain Pieris. The data were recorded on each sampling event in the growing seasons 2011 and 2012. The process of micropropagation in Mountain Pieris was evaluated based on the production characteristics of the regenerants after the 3rd sub-cultivation. The results confirmed statistically significant differences in the number of shoots/explants and in the concentration of chlorophyll a between the dates of the primary culture establishment. The maximum number of shoots/explants (10.9) was obtained in variant B (primary culture established on 07/21/2012) and the highest concentration of chlorophyll a 6.66 mg g–1 on dry matter was found in variant C (primary culture established on 08/24/2011).