Some introduction aspects of genus <i>Hoya</i> plants in greenhouse conditions

Abstract

The paper deals with the study results of genus Hoya adaptive capabilities in protected ground conditions. The objects of the study are four species and one cultivar of the genus: Hoya cumingiana Decne., Hoya globulosa Hook. f., Hoya australis R. Br. ex Traill, Hoya pubicalyx Merrill, Hoya cv. Metallica . In culture, the life cycle of plant development corresponds to the natural one with minor periods of dormancy in autumn and winter associated with a reduction of daylight hours and insolation. For all introduced species, an increase of chlorophyll content and ratio of chlorophyll to flavonoids in the autumn period and minor fluctuations of flavonoids throughout the entire study period were noted, which indicates their relatively optimal nitrogen status. The author has revealed species specificity in the accumulation of chlorophyll and flavonoids and nitrogen balance. The shoot system is characterized by a plagiotropic growth direction and all its vegetative areas are structurally homogeneous. Each single-order stephanotis shoot grows at the top of the stem, shoots can be both short- and long-chamber. Intensive growth and decorativeness of the shoot system of H. globulosa , H. cumingiana and H. pubicalyx , the stability and plasticity of the photosynthetic apparatus provide the prospect of their use in phytodesign.