The germination of seeds of Epiphyllum phyllanthus (L.) Haw. (Cactaceae) is controlled by phytochrome and by nonphytochrome related process

Abstract

The Epiphyllum phyllanthus seeds present high sensitivity to light and their germination can be promoted by dim green safe light through the very low fluence response mediated by phytochrome A. Part of seed population have phytochrome B in active form (Pfr) enough to promote germination in darkness. Seeds of Epiphyllum phyllanthus germinate in a wide temperature range from 10 to 40°C, reaching complete germination in the range of 15 to 30°C. Above 35°C the germination rate increases indicating control by a non phytochrome related process. The analysis of kinetics of seed germination indicated that the phytochrome A control is less dependent on temperature than phytochrome B controlled process.