Assimilatory pigments, photosynthetic activity and ultrastructure of chloroplasts of the variegated-leaf chimera of Acer platanoides L.

Abstract

The assimilatory pigment composition, photosynthetic activity and ultrastructure of chloroplasts were studied in the chlorophyll - deficient chimera of <i>Acer platanoides</i> L. Part of the crown of this chimera is a virescent mutant with variegated leaves. It was found that there exists no qualitative difference in the pigment composition between normal and variegated leaves. The accumulation of chlorophyll in the mutated part is more delayed that the accumulation of carotenoids. The photosynthetic rate on a chlorophyll basis is much higher in variegated than in green leaves. This difference gradually falls off with development. In the early spring, chloroplasts from the yellow spots of leaf blade have no lamellar system but only many vesicles are dispersed in the stroma. Occasionally also a single granum consisting of a few thylakoids occurs in the stroma. At the end of summer chloroplasts from yellow spots of variegated leaves possess a poorly developed lamellar system.