In vitro conservation of essential oil rose cultivars
The effects of explant сonservation in essential oil rose cultivars (Rosa spp.) during the 1st year on their morphometric and physiological parameters during preservation (under the conditions of a slow growth) and after transfer to standard in vitro culture has been investigated. The segments of the microshoots (5-7 mm) of cultivars Raduga, Lany, Lada, Michurinka, and Festivalnaya were kept at 4-6°С and light intensity at 1,000 lx. During storage, viability of the explants of all investigated genotypes was at a high level (90-100%). Herewith, depending on cultivars, in 85.7-100% of explants, a slow development (formation of new leaves, additional buds, and shoots) was observed. The best growth of adventitious shoots was in cultivars Festivalnaya and Lany (1.8 and 2.1 pieces explant‑1, respectively). At a low temperature, the work of photosystem-II in the leaves of all cultivars was reduced: relative photosynthetic activity was 0.41-0.50 a.u. At the same time in control (during а clonal micropropagation in meristem culture) in the studied cultivars, shoots and active light conversion was observed, which indicated normal functioning of their assimilation apparatus. After one year of conservation, the explants were transferred to a fresh culture medium and cultured at 24-26°C with a light intensity at 2,000-3,000 lx under 16-h photoperiod. For all the cultivars within a month, active shoot growth and adventitious shoot formation (from 2.1 to 4.6 pieces explant‑1, respectively) were observed. The multiplication index varied from 4.2 (Lada) to 7.6 (Festivalnaya). Some morphometric parameters were on the control level, and for Festivalnaya and Lany even higher. The analysis of the parameters of chlorophyll fluorescence induction of plant material after transfer to standard in vitro culture conditions indicates restoration of production processes. Cultivars Raduga and Michurinka showed a slight photo inhibition.
Yegorova, N.A., Brailko, V.A., Stavtzeva, I.V. and Mitrofanova, I.V. (2021). In vitro conservation of essential oil rose cultivars. Acta Hortic. 1324, 71-76
Rosa spp., in vitro collection, explants, micropropagation, photosynthetic activity