MORPHOLOGY AND HISTOCHEMISTRY OF GLANDULAR TRICHOMES OF TECTONA GRANDIS LINN. F.

Dr. Mariappan Senthilkumar*

ABSTRACT

Diversity, distribution and density of trichomes and glands of teak (Tectona grandis Linn. f.). „Teak‟ a species is one of the most important timber trees of India. The objective of this study is to understand the morphology of the glandular trichomes and secretary products of glandular trichomes by using light, Ultra Violet and fluorescence microscopy. The chemical content was analyzed by using histochemical reagents. This morphoanatomical and histochemical study revealed that leaves of T. grandis possess four types of non-glandular and two type of glandular trichomes, with the latter differing both anatomically and in the composition of their secondary metabolites. Two classes of glandular trichomes were recognized as globular and reniform. A morphological study of the secretory head and the characterization of the secretory product are also presented. Secretory products of globular trichomes consisted of essential oils, where as reniform trichomes consisted basically of phenolic compounds such as flavonoids. Non-glandular trichomes were in different shape. Peltate and capitate glandular trichomes comprised one basal cell, one stalk cell and one head. The head of mature peltate glandular trichomes consisted of four-twelve secretory cells while that of the capitate glandular hairs was comprised of two cells. The fluorescent stain of peltate and capitate glandular trichomes indicated the possible presence of phenolic compounds.

Keywords: Trichomes, Glands, Histochemistry, Tectona grandis linn.f., Secondary metabolites, Phenolic compounds.