There is limited evidence on bryophyte-tracheophyte allelopathic interactions. Even less is known about such relationships among commercially important plants and mosses. With the aim of screening such interactions, various extract concentrations of nine different mosses were tested on the seed germination and seedlings, i.e., hypocotyl elongation and total chlorophyll content of lettuce and radish. The allelopathic effects are documented to be pairwise (moss-vegetable) and species-specific. Based on the results, the extracts of Leucodon sciuroides and Dicranum polysetum are not harmful to lettuce and radish. Lower extract concentrations of Leucodon sciuroides and Ctenidium molluscum have a positive effect on lettuce development, while those of Thuidium delicatulum, Ctenidium molluscum, and Dicranum polysetum showed to be effective on radish. Further, negative effects were noticed when applying higher extract concentration of Abietinella abietina, Isothecium alopecuroides, Dicranum polysetum, and Racomitrium elongatum to lettuce and Isothecium alopecuroides to radish. The dataset presented in this study offers numerous possibilities for further target pest/vegetable type applications since some of the moss extracts are shown to be positive, negative, or indifferent to the tested features in lettuce and radish.
The two accessions of the polytrichaceous moss species Polytrichum formosum, namely German and Serbian genotypes, were subjected to salt stress, aiming to study the species’ developmental and physiological features. Various concentrations of sodium chloride were applied to an axenic in vitro culture of the two moss genotypes, and the growth parameters as well as physiological feature changes were followed. As inferred by the morpho-developmental parameters and survival index, the Serbian genotype showed higher resistance to salt stress as compared to the German one. However, both moss genotypes survived the highest applied concentration (500 mM). As expected, short exposures to salt were rather easily overcome. No clear patterns in sugar content and changes were observed during the stress, but they are surely included in salt stress response and tolerance in P. formosum. Longer stress increased total chlorophyll content in both genotypes. In short-term applied salt stress, the Serbian genotype had a higher total chlorophyll concentration to control unstressed plants, while the German genotype decreased the total amount of chlorophyll. Similarly, carotenoids were shown to be significantly higher in the Serbian genotype, both in unstressed and treated plants, compared to the German one. The contents of tocopherols were higher in the Serbian genotype in controlled unstressed and subsequently short- and long-stressed plantlets compared to the German accession. In general, we can assume that P. formosum is unexpectedly tolerant to salt stress and that there are differences within various accessions of overall European populations, as referred by two randomly selected genotypes, which is most probably a consequence of different genetic structure.
The rare and threatened pleurocarpous semi-aquatic moss Drepanocladus sendtneri (Amblystegiaceae) was the focus of an integrative conservation approach aimed at improving knowledge of its biological and ecological characteristics and enhancing its survival prospects. The results provide insights into both the axenic and xenic propagation of this species, as well as its biomass production under ex situ conditions. The KNOP medium proved to be the most suitable for propagation, particularly when demeristemized shoot tips were cultured in an upright orientation. Exogenous application of IBA increased the production of new shoots and reduced the time required to obtain substantial biomass under axenic conditions. Following successful acclimatisation to controlled xenic laboratory conditions, the moss was able to fully develop and spread in experimental basins maintained under outdoor botanical garden conditions, with humidity carefully regulated during dry periods. Within one year, a small number of initial plantlets expanded to cover approximately 4 dm2, spreading efficiently over rainwater-soaked filter paper covered with an inert plastic mesh. These results provide practical guidance for the production and ex situ maintenance of D. sendtneri, thereby supporting the development and improvement of conservation action plans for this rare and threatened moss species.