Using of phytomonitoring data for eco-physiological evaluation of the environmental factors limiting development of ornamental plants
The results of the ecological assessment of the physiology of different plant species using phytomonitoring data allows differentiation between species according to the peculiarities of their water regime, drought resistance and shade tolerance. This issue is particularly important for the successful introduction of species into cultivation. This research used young plants of Nerium oleander L., Laurus nobilis L. and Aucuba japonica Thunb. var. variegata. For continuous automatic recording of CO2/H2O gas exchange of intact leaves, plant growth and water balance, the photosynthesis monitor RTM-48A and phytomonitor PM-11z were used. Genotypic features of evergreen ornamental plants in supporting optimal water balance in accordance with environmental conditions were determined. Optimal light, temperature, and soil moisture conditions for intensive growth were determined for N. oleander: leaf temperature from 23 to 36.5°C; light regime: full sunlight in the range photosynthetically active radiation (PAR) 850-1600 µmol m‑2 s‑1; soil moisture of 45-75% field capacity (FC); for L. nobilis: leaf temperature from 24 to 32°C; light regime: full sunlight, part-shade or shade in the range PAR 350-1650 µmol m‑2 s‑1; soil moisture of 45-75% FC; for A. japonica: leaf temperature from 15 to 26°C; light regime: part-shade or shade in the range 300-1250 µmol m‑2 s‑1 (15-60% of full light); soil moisture 70-90% FC. With increasing levels of irradiance above 1300 µmol m‑2 s‑1 photoinhibition impairs light acclimation and can cause photo-oxidative damage of the photosynthetic apparatus of A. japonica, which must be considered in the cultivation of this species. One of the specific adaptation reactions for N. oleander to long-term extreme water stress, high levels of irradiance and overheating, is the accelerated senescence and defoliation of not only old but also young leaves, resulting in the loss of ornamental value. These data may be effectively used also of value for landscape designers for selecting appropriate plants for specific locations for plant research and for commercial crop growing.
Pashtetsky, A., Plugatar, Y.V., Ilnitsky, O. and Korsakova, S. (2019). Using of phytomonitoring data for eco-physiological evaluation of the environmental factors limiting development of ornamental plants. Acta Hortic. 1263, 199-206
woody ornamental plants, photosynthesis, water regime, light regime, temperature conditions