New Natural Growth Inhibitor in the Liverwort Lunularia cruciata (L) Dum.

Abstract

THE growth of the Israel strain Lunularia is highly sensitive to photoperiod^1,2 and, in long day conditions, particularly at high temperatures, it rapidly becomes dormant. The dormant thalli can be preserved in the air-dry condition for several years without losing their capacity to resume growth, although thalli growing actively in short day are killed by dry conditions. Light break experiments by Wilson and Schwabe³ using narrow wave bands at 735 nm and 650 nm have shown that the day-length response is controlled by phytochrome, which has suggested that dormancy is induced by an endogenous inhibitor.