Studies on bud development in the rhizome of Agropyron repens. 1. The influence of temperature, light intensity, and bud position on the pattern of development

Abstract

When plants of Agropyron repens L. Beauv. are grown at a low nitrogen level, decapitation of the rhizomes releases the lateral buds from inhibition and results in a well-marked polarity of bud development. This polarity is typically characterized by the restriction of shoot development to the bud nearest the apical end of the rhizome, the production of rhizomes from buds at a greater distance from the apex, and a tendency for the buds at the basal nodes to remain inhibited.It was shown that this pattern of bud development is readily affected by environmental conditions. Increasing the temperature from 15° to 25 °C caused a marked increase in shoot formation at the expense of rhizome production and a small increase in the number of dormant buds. Reducing the light intensity had a similar but much more pronounced effect. The position of the buds in relation to the cut end of the rhizome was relatively less important as a morphogenetic factor than their position on the intact plant.As a working hypothesis, based on previous results, it is suggested that a gradient in the C/N ratio might account for the observed polarity of bud development.