ISSN 1021-4437, Russian Journal of Plant Physiology, 2016, Vol. 63, No. 4, pp. 474–482. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © N.A. Tikhomirova, S.A. Ushakova, E.S. Shklavtsova, O.V. Anishchenko, Yu.A. Mikheeva, A.A. Tikhomirov, 2016, published in Fiziologiya Rastenii,
2016, Vol. 63, No. 4, pp. 504–513.
Effects of PAR Intensity and NaCl Concentration on Growth
of Salicornia europaea Plants as Relevant
to Artificial Ecological Systems
N. A. Tikhomirova, S. A. Ushakova, E. S. Shklavtsova, O. V. Anishchenko,
Yu. A. Mikheeva, and A. A. Tikhomirov
Institute of Biophysics, Siberian Branch, Russian Academy of Sciences,
Akademgorodok 50, Krasnoyarsk, 660036 Russia
Received March 23, 2015
Abstract—Effects of variable levels of photosynthetically active radiation (PAR) and NaCl concentrations,
typical of closed ecological life support systems, on growth of Salicornia europaea L. plants, CO
mineral composition, and the content of malondialdehyde (MDA) and photosynthetic pigments were inves-
tigated. The plants were grown for 25 days at different salinities of nutrient Knop solution (171, 342, and
513 mM NaCl) under two PAR levels (690 and 1150 μmol/(m
s)). At PAR of 690 μmol/(m
s), the plant pro-
ductivity did not show significant changes at increasing salinities; at 1150 μmol/(m
s), the maximal produc-
tivity was observed at NaCl concentrations of 171 and 342 mM. The increase in NaCl concentration from
171 to 513 mM in the nutrient solution led to a substantial increase in the relative Na content in aboveground
organs at PAR level of 1150 μmol/(m
s). The MDA content in aboveground organs by the end of the growth
period was independent of PAR intensity. The content of photosynthetic pigments in the assimilatory tissue
decreased with the increase in salinity from 342 to 513 mM NaCl at PAR level of 1150 μmol/(m
s) but not at
the lower irradiance. The combination of 1150 μmol/(m
s) PAR intensity with the salinity as high as 342 mM
NaCl was found to be the most effective for optimal productivity of S. europaea plants.
Keywords: Salicornia europaea, NaCl salinity, PAR intensity, productivity, CO
photosynthetic pigments, MDA, artificial ecosystems
Salicornia europaea L. (glasswort) is an annual
plant and a typical salt-accumulating halophyte that
can grow at a wide range of salt concentrations in soil
and accumulates up to 50% of sodium chloride in dry
matter [1–3]. The aerial part of the plant is completely
edible for humans [4, 5]. S. europaea plants can be
used for remediating the fertility of saline soils in nat-
ural conditions. Owing to high nutritional value and
salty taste, the plant can be used as a vegetable crop for
seawater commercial farming . Because of its phys-
iological characteristics, this plant species is a promis-
ing candidate for growing in artificial closed ecological
systems under space flights conditions .
At various intensities of photosynthetically active
radiation (PAR) and photoperiodic conditions with a
day length of 12–18 h, S. europaea plants can tolerate
salinity of more than 1000 mM NaCl, although opti-
mal NaCl concentration for growth of S. europaea
ranges from 170 to 400 mM [8–12]. Nevertheless, the
literature data on salt tolerance and growth of S. euro-
paea plants at various PAR intensities are very scarce.
Long days and high photon flux densities were
reported to prevent the premature flowering of Sal-
icornia plants .
We found earlier that the production process in
S. europaea plants grown under 24-h lighting can be
effectively controlled by the concurrent changes in
salinity of nutrient solution and PAR intensity .
However, the data obtained thus far were insufficient to
determine growth conditions ensuring optimum plant
productivity and the highest possible Na content in
aboveground organs. The development of such growing
regimes would be useful for creating long-term closed
environments (e.g., space stations), where metabolic
waste is recycled based on biological principles, as well
as for agricultural cultivation of S. europaea.
The aim of this study was to examine the influence
of PAR intensity and salinity on photosynthetic pro-
ductivity and accumulation of Na in S. europaea plants
in relation to artificial closed ecosystems.
Abbreviations: CES—closed ecological system; Chl—chloro-
phyll(s); PAR—photosynthetically active radiation