Environ Exp Biol (2024) 22: 29–40

Comparison of two subspecies of a halophytic multi-use plant Mertensia maritima in vitro and ex vitro: propagation, salinity tolerance and mineral nutrition

Abstract

The aim of the present study was to compare morphological and physiological responses to increasing salinity of the two subspecies of Mertensia maritima during in vitro propagation in two different systems, and subsequent ex vitro cultivation. Plants were brought into culture using seeds and further propagated on Murashige and Skoog medium supplemented with thidiazuron and naphthaleneacetic acid either on agar-solidified or liquid medium with a temporary immersion system (Plantform bioreactors). Salinity tolerance were tested both in tissue culture and with ex vitro greenhouse-cultivated plants. Low concentration of NaCl increased explant biomass in agar-solidified medium, with no negative consequences even at high concentration. However, the effect of salinity on liquid medium was genotype-specific. Explants in Plantform bioreactors showed several-fold higher biomass in comparison to that on agar-solidified medium, but the multiplication potential was not significantly affected. Ex vitro plants were negatively influenced by increasing NaCl concentration in substrate. In contrast to in vitro plants, accumulation potential of Na⁺ in ex vitro plants was low. One of adaptations to salinity at the whole plant level was maintenance of adequate tissue mineral nutrient homeostasis, as mineral nutrient concentrations were not negatively affected by increasing salinity.