Transformation of the domain pattern in the development of Fagus silvatica L. cambium

Abstract

The domain pattern of cambium during the first year of its function in Fagus silvatica L. resembles a checkerboard. The longitudinal line along the leaf trace, its corresponding line on the opposite side of the internode and nodes comprise the domain borders. Starting from the formation of the first annual ring, this checkerboard pattern begins to undergo gradual transformation. A transitional domain pattern appears during the first few years; in each internode, due to the alternate disappearance of Z and S domains, a fragmentary domain of one type and an expanded domain of the opposite type occur in pairs. After further transformations, a regular pattern of transverse bands of domains moving along the stem appear on older stems (over ten years-old). This pattern is commonly found in other studied species of trees.