Controlled Differentiation in Cultures of Two Liverworts

Abstract

IT is well known that relatively undifferentiated tissues of many vascular plants can be grown continuously in aseptic culture, and, under appropriate conditions, may often be induced to produce normal fully differentiated organs¹. Similar cultures do not appear to have been described for any of the bryophytes. Wettstein^2,3 obtained undifferentiated apolar tissue from spores of Funaria, by growing them on media containing relatively high concentrations of thiamine or of narcotics such as chloralhydrate, but the cell masses produced never comprised more than 30–50 cells. Meyer⁴ observed similar clumps of rounded cells in cultures prepared from the spores of an unnamed leafy liverwort (probably Cephaloziella) but after several months the clumps gave rise to leafy shoots. In contrast with the restricted growth described in these previous investigations, the active and apparently unlimited growth of a callus-like tissue has now been obtained in two representatives of the liverworts—Fossombronia pusilla (L.) Dum. (Jungermanniales Anacrogynae) and Reboulia hemisphaerica (L.) Raddi (Marchantiales).