Effects of salt on selected bryophyte species tested under controlled conditions

Bryophytes inhabit all ecosystems on the Earth except seas. Thus, it is commonly accepted to ask are there real halophytes among bryophytes? However, some species do inhabit salty grassland or even brackish waters. Not much research has been done on the physiological reaction of moss species to salt stress. In order to study these responses, we selected three moss species, two of which are considered to be halophytes?Entosthodon hungaricus (Funariaceae), Hennediella heimii (Pottiaceae) and the non-halophytic model moss Physcomitrella patens (Funariaceae) and tested salt effects on them in controlled conditions. The idea was to show if there is tolerance to salt in the selected moss species and to document it if there is a difference in salt tolerance among them. Established in vitro moss cultures of gametophores were used to test various developmental parameters for the selected moss species. Morpho-developmental parameters (secondary protonema diameter and the index of multiplication) and biochemical parameters (pigment content and antioxidative capacity) were analysed in relation to salt concentration and time of exposure. All of the tested moss species tolerated salt stress to some extent and during some time of exposure to it. Recovery after salt stress depended both on the concentration of salt and duration of the stress. The three tested moss species did not show similar patterns of response to salt stress.