Morphological and physiological features of the miniature rose cultivar 'Rise'n'Shine' under long time culture in vitro and in vivo

V.A. Brailko, S.A. Plugatar, T.I. Pilipchuk, Yu.V. Plugatar, I.V. Mitrofanova
Due to the early, long-term (over 200 days) and multiple repeated flowering, miniature roses (Rosa chinensis var. minima (Sims) Voss) are very popular in southern Russia. The morphogenetic and adaptive capacity of hardly propagated perspective cultivar ‘Rise’n’Shine’ from the collection of the Nikita Botanical Gardens cultured in vitro and in vivo was analyzed. The microshoots were regenerated on MS medium with 0.25 and 0.50 mg L-1 BAP in a growth chamber (24±1°C, 16-h photoperiod, 37.5 μmol m-2 s-1). The term of in vitro culture was 2 years. Adaptation in vivo and a subsequent cultivation of plantlets were carried out in the greenhouse for one year. Under in vitro conditions 1-3 microshoots per explant were obtained, 5.2-5.6 cm height with 9-16 ternate leaves. Leaflets’ size was 0.4×0.5 cm. Leaf blades were of bifacial type, 92±6 μm thick, covered with a single layer of epidermis and a thin cuticle. Mesophyll was differentiated and consisted of one palisade cells layer and 3-4 layers of spongy tissue. Palisade ratio was 0.47. The leaves were hypostomatic, stomatal apparatus were of anomocytic type, 270-292 stomata mm-2 of adaxial epidermis. The hydration was 86% with a bound water part – 53% of the total water content. Photosynthetic activity was 0.66-0.70 relative fluorescence units (RFU). A plant height ex vitro was 15.3-31.8 cm. Each plant had 5-7 shoots with imparipinnate leaves (with 5 leaflets). The leaflets were up to 2.5 cm long. Leaf blade thickness was 172±14 μm, the cuticle – 3-6 μm, single-layer mesophyll – 5-7. Palisade ratio was 0.58. Stomata length – 18-20 μm; 120-136 stomata mm-2. The total water content was lower than in the microshoots in vitro – 74%, and the part of bound water was 78%. Photosynthetic activity increased up to 0.82 RFU.
Brailko, V.A., Plugatar, S.A., Pilipchuk, T.I., Plugatar, Yu.V. and Mitrofanova, I.V. (2018). Morphological and physiological features of the miniature rose cultivar 'Rise'n'Shine' under long time culture in vitro and in vivo. Acta Hortic. 1224, 139-144
DOI: 10.17660/ActaHortic.2018.1224.19
Rosa chinensis var. minima, in vitro regeneration, plantlets, leaf structure, water regime, adaptation in vivo

Acta Horticulturae