Application of Horticultural and Tissue Culture Methods for Ex Situ Conservation of Endangered Primula farinosa L.

Our study aimed at active conservation of the last location of Primula farinosa, an endangered species in Poland, and assessed reproduction by seeds and plant propagation on sterile media in tissue culture conditions. We identified gibberellic acid (GA3) as the key factor stimulating germination of P. farinosa seeds. Growing juvenile plants under controlled temperature of 18/16 °C day/night yielded good quality plant material without mycorrhization. In tissue culture, the most favorable medium for shoot propagation was MS supplemented with the lowest tested concentration of indole-3-butyric acid (IBA; 0.05 mg dm−3) and 6-benzyl-aminopurine (BAP; 0.1 mg dm−3). The rooting ability of shoots was high and comparable for all auxins used. 2C DNA content of seed-derived and micropropagated plants did not indicate any change in the ploidy level during in vitro cultivation. Plants derived from seeds and tissue cultures were compared in a 2-year study. Of all the characteristics compared, only the number of flowers per inflorescence was lower for micropropagated plants when compared with the seed-origin plants in the first year of observation. The difference was of transient nature and was not observed in the second year of the study. Effective protocols for in vivo and in vitro propagation of P. farinosa were developed, which can be used in practical species protection.