BIOLOGICAL STIMULATION IN GERMINATION

Abstract

Introduction:

MANY seeds, spores, and pollen grains will only germinate when they are associated with active independent tissues. Moreover, many of the characteristics of the situation are strikingly similar in the different groups. Some of these similarities have already been emphasized by other writers, others have not. It is the purpose of this article to provide a general review of the subject based on the contention that many of the similarities are sufficiently close to warrant the hypothesis that the same phenomenon is involved throughout the several groups. The subject is one of some significance in two connexions. An examination of the nature of the stimulation contributes to an elucidation of one aspect of the germination process and is therefore relevant to a consideration of the factors involved in dormancy. Secondly, as indicated below, the effect is undoubtedly due to the production by the active tissue of particular chemical activators which promote the development of the dormant unit. It is probable that many of these have not hitherto been isolated and identified, and the topic has therefore important implications for the general subject of growth-promoting substances.