A comparative study of generation from isolated gametophytic tissues in Mnium

TitleA comparative study of generation from isolated gametophytic tissues in Mnium
Publication TypeJournal Article
Year of Publication1961
AuthorsLersten NR
JournalThe Bryologist

1. Isolated leaves of six species and one variety of Mnium were cultured in Knop's medium and analyzed for their pattern of proliferation. 2. No leaves with attached stem tissue proliferated except in M. affine and M. stellare. 3. Isolated leaves of M. spinulosum and M. cuspidatum showed no reaction: M. affine and M. stellare had generalized distribution while the other three species showed costal and extramarginal basal proliferation and marginal proliferation distally. 4. Under the experimental conditions it was impossible to separate definitely all species on the basis of their proliferation distribution. 5. All species except M. pseudopunctatum had a marked increase of proliferation from the abaxial surface. 6. This abaxial selectivity continued no matter which surface was in contact with the substrate, but contact surfaces always had more proliferation than the same surface not in contact. 7. Paraphyses of six species tested proliferated only in M. affine and M. stellare, and in these from the basal cell. 8. Leaves of M. punctatum var. elatum, with attached stem sections, were severed at costa only, margin only, lamina only, and not at all (control). Greatest proliferation followed costal severance, and much less followed marginal severance; none occurred in the other two cases. 9. Stem proliferation was usually only from the leaf margins which continued as ridges down the stem. Internal stem tissue did not produce proliferations. 10. Internal mechanisms of proliferation, in terms of regulatory substances, are discussed.