Studies On Adaption Of Some Ornamental Mosses To Aquatic Environments And Tissue Culture

Bryophytes are important ornamental species in landscaping, and have a goodapplication prospect in the urban vertical greening and aquarium market. Racomitriumjaponicum is a candidate species for vertical greening in cites, however, it growsslowly in the field. In order to apply R. japonicum in greening, we should master itsrapid reproduction technology. The present paper studies the suitable environmentalconditions for the protonemata growth of Racomitrium japonicum protonemata undertissue culture conditions, providing revalent techniques for the possible application ofthe species in city greening in the future.China is rich in bryophyte species, some of them are of potential values asaquarium plants because of their predominance in domestication and breeding inaquarium. However, there are few aquatic bryophytes in eastern China. Therefore, itis practical for us to find some bryophytes suriviving in aquarium conditions fromterrestrial bryophytes. In the present paper, we studied the adaption of ten terrestrialmoss species in water by determination their chlorophyll fluorescence indices undertheir different submersion times in water. We also determined the physiologicalindices of four moss species under different water conditions in relation to aquariummanagement, thus to provide technology and methods to make use of bryophytes inthe aquarium market. The main results are as follows:1. The components of culture media have significant effects on the growth ofRacomitrium japonicum protonemata. The improved Knop’s culture medium is moresuitable for Racomitrium japonicum protonemata to grow than MS culture medium.There exists an optimal nutrient concentration of culture medium for the growth ofRacomitrium japonicum protonemata. Compared with the ordinary media, those with higher or lower concentrations of-KNO3、KH2PO4、Ca(NO)4·4H2O are no good forthe growth of Racomitrium japonicum protonemata. The growth of Racomitriumjaponicum protonemata in the improved Knop’s culture medium with lowconcentrations of6-BA is similar to the the control. However, the improved Knop’sculture medium with six different ratios of6-BA to NAA has inhibitory effects on thegrowth of Racomitrium japonicum protonemata. Its Protonema begin browning,rhizoid significantly increased and the number of chloroplast dropped significantlywhen Racomitrium japonicum cultivated on the culture medium with double contentof6-BA and NAA.2. We studied the adaption of Hypnum plumaeforme，Fissidens zippelianus，Fissidens plagiochloides, Campylopus ericoides, Bryum billarderi, Trichostomumaristatulum, Racomitrium japonicum, Polytrichastrum formosum, Leucobryumglaucum and Leucobryum scabrum in water by determination their chlorophyllfluorescence indices under their different submersion times in water. Variation trendsof Fv/Fm, Pm and α show that Hypnum plumaeforme, Fissidens zippelianus,Fissidens plagiochloidesm, Campylopus ericoides, Bryum billarderi andTrichostomum aristatulum are able to survive in water，and their morphologicalcharacteristics did not change much, showing their potential application value inaquarium landscape. While Racomitrium japonicum, Polytrichastrum formosum,Leucobryum glaucum and Leucobryum scabrum are not suitable to grow in water.3．We simulated aquatic environments with different pH values, water qualityregulators, light hours and temperatures, and determined chlorophyll fluorescenceparameters, Chlorophyll content, MDA content and Free proline content of Hypnumplumaeforme, Philonotis turneriana, Pyrrhobryum spiniforme and Plagiochilapulcherrima. Our experiments show:Hypnum plumaeforme is suitable for acidic or slightly acidic water environmentin complete illumination (3000-4000Lux) about20℃. Too high or too lowtemperatures have inhibitory influences on the growth of Hypnum plumaeforme.Hypnum plumaeforme is very sensitive to algicide, nitrobacteria and snail killers. The water with algicide, nitrobacteria and snail killers cause somewhat stress to Hypnumplumaeforme. In order to meet the normal growth needs of Hypnum plumaeforme, thelighting time shouid kept for12hours (3000-4000Lux) or longer.Philonotis turneriana is able to grow in acidic or slightly acidic water with24hours complete illumination (3000-4000Lux) under20℃. Different light length has asignificant influence on the growth of P. turneriana. The optimal temperature is about20℃and the optimal pH is5. Algicide, nitrobacteria and snail killers also caused astress on P. turneriana, having inhibitory effects on its growth.The responses of Pyrrhobryum spiniforme to water conditions are similar tothose of P. turneriana, only the latter responds well with12-hours light (3000-4000Lux). Though algicide, nitrobacteria and snail killers have inhibitory effects on thegrowth of P. turneriana, snail killers has the most.Plagiochila pulcherrima grows well in water with pH4, uner24-hours completeillumination (3000-4000Lux) and20℃. The species is rather sensitive to algicide,nitrobacteria and snail killers too.