カゼクサ種子の発芽における光週期的処理

Abstract

1. Light is obligatory for the germination of Eragrostis seeds but the dark period corresponding to that in flowering of short-day plants is required immediately after soaking. And the high-intensity-light process prior to the dark process is not observed. Germination is maximal under the dark period of 24hrs. followed by light and decreases under continuous light irradiation.2. The germination-promoting effects of the long dark period are inhibited by brief interruptions with red, blue or far-red energy, such interruptions being most effective for red and blue at the 9th hr. after the start of the dark period, and for far-red energy in the latter half of the dark period.3. Repeated alternations of red and far-red radiant energies repeatedly result in red inhibition and far-red repromotion of germination in the first half of the dark period, but not in the latter half.4. Another important feature is the photocontrol of germination by a succession of alternate blue and far-red irradiations in the first half of the dark period. The germination is regulated by the light last received, being inhibited with blue energy and repromoted with far-red.