Leaf morphological and anatomical features of some cultivars of hybrid tea roses and their drought resistance when grown on the southern coast of the Crimea

Because of their high decorative qualities, resistance to diseases, long-term and remontant flowering, hybrid tea cultivars of garden roses are widely used for green construction in the dry subtropical climate of the southern coast of the Crimea (SCC). However, the high probability of drought on the SCC in July-August may have a negative impact on the decorative properties of some cultivars.
While analyzing anatomical and morphological features of leaf blades and some parameters of water regime of three cultivars of different stages of breeding hybrid tea rose ‘La France’ (the first cultivar of hybrid tea group created in 1867), ‘Gloria Dei’ (created in 1945) and ‘Traviata’ (created in 1998) in the period of maximum probability of drought occurrence on the southern coast the correlation between water-holding capacity of leaf tissues, their thickness, size of epidermal cells and thickness of the adaxial cuticle was noted.
A number of xeromorphic features, typical for both studied cultivars and garden rose culture as a whole were identified.
It was found that the maximum thickness of the cover tissues and leaf blades in general, a more powerful sclerenchymatous frame of vascular bundles, small intercellular spaces, crystals in collenchyma cells allow us to attribute ‘Traviata’ to cultivars with the most pronounced xeromorphic features.
Along with this, the loose structure of the mesophyll of the leaves of ‘Gloria Dei’ and the low thickness of the leaf and cover tissues in ‘La France’ are the signs of less xeromorphism.
The revealed anatomical and morphological parameters contribute to the development of a high level of water-retaining forces, and, accordingly, a high degree of drought resistance of the leaf apparatus of ‘Traviata’ and ‘Gloria Dei’. The actual water deficit that develops under stressful hydrothermal conditions does not reach a semi-lethal value.
The properties of the structural organization and features of the water regime of the studied cultivars of hybrid tea roses allow them to be successfully cultivated in the conditions of the hydrothermal regime of the SCC growing season.
To maintain maximum decorativeness, ‘La France’ needs regular intensive watering.

II International Symposium on Tropical and Subtropical Ornamentals

Yu.V. Plugatar, V.A. Brailko, S.A. Plugatar, T.B. Gubanova, Z.K. Klimenko, V.K. Zykova

cuticle, mesophyll, xeromorphic features, mesomorphism, water regime

https://doi.org/10.17660/ActaHortic.2022.1334.13