Regeneration from the Leaf of Atrichum undulatum (Hedw.) P. Beauv.

Abstract

Regeneration of new plants from the leaves of Atrichum undulatum will take place after 6 weeks if they are placed with the abaxial surface in contact with damp filter-paper in a saturated atmosphere.

The new plants arise from the surface cells of the midrib area of the leaf where there is a discontinuity of the photosynthetic filaments. This occurs mainly in the distal third of the leaf.

As the leaf ages it loses it capacity for regeneration. There are two regeneration processes, one which occurs when the leaf is separated from the stem and the only wound is at the point of attachment to the stem, and the second when other wounds are inflicted on the leaf. Regeneration due to wounding is greatest in the distal half of the leaf, mutilations near the base of the leaf having less effect on the percentage of regenerated plants.

There seems to be a potential for regeneration (both normal and as a result of wounding) which is greatest in the distal third of the leaf and decreases towards the base of the leaf of A. undulatum. This is compared with the leaf of Physcomitrium turbinatum, and the greater complexity of the process in the former is considered to be the result of greater differentiation of the leaf.