Influences of mature plants and desiccation on germination of spores and gametophyticfragments ofTortula

Abstract

AbstractThe germination and establishment abilities of different types of propagules under natural conditions is an area in bryophyte reproductive biology that is largely unknown. In some species gametophyte fragments, rather than spores, may be primarily responsible for establishment of new colonies in nature, and the presence of other mosses may have an effect on establishment processes. These ideas were tested experimentally using four species of Tortula grown in a glasshouse under semi-natural conditions. The relative germination and growth abilities of spores and gametophytic fragments were tested under each combination of the following treatments: (1) continuous hydration (using a mist system), or periodic drying; (2) substrate of bare sand, a clump of Dicranum scoparium, or (for spores only) the clump of Tortula from which sporophytes were taken. Fragments produced new shoots much more quickly than spores under either hydration condition but spores germinated at a higher rate. Germination rates of ...