Portugaliae Acta Biologica, 11: 373-84 (1970)
Influence of different light conditions on hormonal control of leaf-embryo development in Bryophyllum.
M. J. Viana, M. C. Novais

In studies on B. fedtschenkoi grown under natural long days in the greenhouse IAA activity was detected in the leaves and disappeared 24 hours after detaching them. Under L. D. "leaf embryos" did not develop into intact plants. When half the surface of a detached leaf was illuminated, "leaf embryos" developed earlier in the darkened half than in the illuminated half. When the lower leaf surface was turned uppermost there was only 36% inhibition of "embryo" development as compared with 70.5% inhibition when the leaf was positioned normally. "Embryo" development did not differ significantly between totally illuminated or darkened leaves, however. The ratio of inhibitor to kinetin-like substances and the percentage inhibition of "leaf embryo" development were positively correlated. Inst. bot., Lisbon.