Induction of callus in the liverwort Marchantia palmata Nees

Abstract

In Marchantia palmata Nees, normal growth of thalli occurs on Nitsch's basal medium with 1% sucrose. With 4% sucrose, dark green callus is initiated by light intensities of 150–4,500 lux after 13–15 days of growth. In the dark only rhizoids develop from callus and at low light intensity (150 lux) rhizoids as well as knob-like green outgrowths differentiate. Increased light intensities induce differentiation of thalli and rhizoids from callus. The callus inducing effect of increased sucrose level can be replaced by higher concentrations of mannitol. Histological studies reveal that callus initially arises from the lower epidermis.