V. Badzhelova¹, V. Bozhanova², G. Chokov³,

¹Institute of Roses, Essential and Medical Cultures, 6100 Kazanlak, Bulgaria

²Field Crops Institute, 6200 Chirpan, Bulgaria

³Industrial plants company, 6100 Kazanlak, Bulgaria

(Manuscript received 25 May 2018; accepted for publication 22 June 2018)

Abstract. The influence of major factors such as explant sterilization, plant growth regulators in the multiplication and rooting media and the genotype on the in vitro multiplication of White Oil-Bearing Rose (Rosa alba L.) was studied. Explants used in the experiment were 1.0 to 1.5 cm long nodal segments from specially cultivated mother plants. The combination of two disinfectants in the following order: 0.2% HgCl₂ solution for 3 min followed by treatment with 0.5% NaClO solution for 20 min and 0.25% NaClO for 30 min was determined as the most suitable sterilization scheme. The best results of multiplication were obtained in basic MS medium with added BAP in concentration of 0.5 to 3.0 mg/L. The analysis of the variance reveals that the genotype, media variants and interactions between them have a statistically significant influence on the variation of the total number of induced adventive shoots. The highest percentage of successfully rooted young plants (97.5% on average for both genotypes) was obtained in ex vitro conditions by direct rooting in a soil mixture.