Histochemical Studies of the Transition from Sapwood to Heartwood in Tectona Grandis

Abstract

Histochemistry of the wood of Tectona grandis Linn. f. (Verbenaceae) has been studied during the transition from sapwood to heartwood. Starch, lipids, proteins, nucleic acids, phenolics and the enzymes peroxidase, succinate dehydrogenase, acid phosphatase, adenosine triphosphatase and glucose-6-phosphatase show significant changes during the transition. Peroxidase and adenosine triphosphatase are highly active in the sapwood and moderate in the transition zone while succinate dehydrogenase, glucose-6-phosphatase and acid phosphatase are moderate throughout the sapwood.