Common garden experiments with Sphagnum in axenic culture

AbstractAxenic culture conditions which supported adequate to relatively rapid growth and development of Sphagnum species were used to conduct common garden experiments with two taxa in Section Isocladus and four in Section Cuspidata. Our main objective was to determine if certain variable taxonomic characters (e.g. hemi-isophylly vs hetrophylly) are ‘genetically fixed’ or environmentally induced. We found that heterophylly and toothing of branch leaf margins were not ‘genetically fixed’ in the taxa we investigated. All taxa were isophyllous under uniform growing conditions. Characters that appeared least subject to environmental modulation were general growth habit and histological characters of branch leaves. Under common garden conditions, both taxa in Section Isocladus remained distinct, but only three of the four taxa in Section Cuspidata did.