Influence of the spectral composition of light on the morphogenesis of seedlings of <i>Myrtus communis</i> L. and <i>Psidium cattleianum</i> Sabine (<i>Myrtaceae</i> Juss.) in a small pot greenhouse culture

Abstract

The influence of the intensity and spectral composition of LED and fluorescent (FL) light on the morphogenesis of Myrtus communis L. and Psidium cattleianum Sabine (Myrtaceae) seedlings in a small pot greenhouse culture in the Central Botanical Garden of the National Academy of Sciences of Belarus (CBG) was studied. It was shown that in terms of plant height, the number and total surface of leaves, as well as the specific dry weight of the leaf, seedlings of both species over 120 cultivation days in all variants with irradiation surpassed control plants. The increase in dry weight per 1 cm2 of leaf (mg with respect to the control) that characterizes the photosynthesis productivity was influenced by the spectral composition of radiation, which made it possible to identify interspecies and intervariant differences. The variant with an FL Narva lamp with a total photon flux density PFD = 76.22 µmol/m2/s, with a share of the green spectrum PFD-G = 46.47 %, red – PFD-R = 20.00 % and with the value of the ratio R/FR = 5.77 in the subtropical long-day species M. communis, it was 1.24 mg, while in the tropical short-day species P. cattleianum had only 0.39 mg. In plants irradiated with an LED lamp with a photon flux density PFD = 186.20 µmol/m2/s, with a share of PFD-R = 59.34 %, and at R/FR = 54.43, the growth was 2.60 and 1.93 mg with respect to control, respectively. LED sources are the most efficient in terms of the photosynthesis productivity for both short-day and long day plants.