An introduction to the conservation physiology of bryophytes is given. The insights into the problems, solutions and examples of the physiological approach to conservation within bryophyte representatives are discussed. The significance of experimental treatments of bryophytes is highlighted. The documentation of bryophyte functional traits and eco-physiological mechanisms in the conservation background for protection purposes is highlighted by the selected examples. The introduction of bryophytes into a new scientific field is resumed and some insights from specific case studies are presented.

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.

The effects of NaCl and ABA on selected bryophyte species were studied. Two phylogenetically unrelated halophyte mosses, namely, Entosthodon hungaricus and Hennediella heimii, in addition of one model non-halophyte moss, Physcomitrella patens, were selected to compare the variability in certain biochemical and physiological parameters under salt-stress alone and salt-stress upon ABA pretreatment. The results showed different patterns of ABA effects in all three studied species, as well as no common response to salt stress. In general, all tested species reacted to exogenous ABA, which surely contributed to changes observed in morphological development under salt stress, and to salt-tolerance mechanism function. Physcomitrella patens proved to be a salt tolerant species. Although it is not ecologically classified as a halophyte, these results highlighted that various stress-resistance pathways are supported by similar reactions to different stresses. Significant differences in stress tolerance were documented between the two bryo-halophytes tested by comparing biochemical and physiological parameters. Our findings suggested that different salt stress-tolerance strategies characterize these two species, both enhanced by exogenous ABA.

No abstract

The rare moss species Hennediella heimii (Pottiaceae) was established in in vitro culture. Various treatments were tested to achieve axenical cultures. The most effective sterilising procedure was NaDCC treatment of sporophytes, keeping the spore viability and giving high disposal of xenic cohabiting organisms. The effects of plant growth regulators were studied regarding new shoot formation, i.e. bud formation on the protonemal filaments and protonemal patch size. Low concentrations of cytokinin and medium concentrations of auxin are shown to increase protonemal patch size and shoot production. Multiplication of H. heimii was observed to occur spontaneously on BCD medium type, but to achieve better and rapid biomass production and development it is suggested to grow it on a BCD medium enriched with auxin and cytokinin combined.