Photosynthetic pigments, chloroplast distribution and fine structure in vegetative buds of two spruce species

Vegetative buds of spruce represent a developmental stage of the shoot. The rapid changes in anatomy and physiology of buds occur when the proliferation takes place. Chloroplast distribution and ultrastructure as well as the annual dynamics of photosynthetic pigments were investigated in two spruce species. It was found that chloroplasts inside the vegetative buds are distributed in the medula and needle primordia. They contain a poorly developed thylakoid system and starch grains. The exposure of young needles to environmental light did not cause the expected rapid increasa in photosynthetic pigment content. The young needles needed a longer period of time (May to August) to reach the same level of photosynthetic pigments content as the needles formed in the previous season.