Die morfologie en ultrastruktuur van die blaartrigome van Nicotiana tabacum L.

Abstract

Light- and electron microscopical studies were conducted on the leaf trichomes of a few Nicotiana tabacum L. cultivars to determine whether a correlation exits between the trichome complement and the aromatic quality of the cultivar. Two major types of trichomes are distinguished, namely long and short trichomes. Both types are present on the abaxial and the adaxial leaf surfaces at different stages of leaf development . As the developmental patterns of the trichome types differ the two types can readily distinguised from one another at an early stage. The cell wall composition of the long and short trichomes is similar but the composition of the secretory product differs, although lipophilic substances are secreted by both types . Different organelles are probably involved in the production of the secretory product of the two trichome types. The secretory product of the long trichomes is probably produced by the plastids and smooth endoplasmic reticulum, and is believed to be transported by the smooth endoplasmic reticulum to the cell wall where it is released. In the short trichomes the rough endoplasmic reticulum associated with the large number of mitochondria is probably involved with the production of the secretory product which is transported by the rough endoplasmic reticulum to the sub-cuticlar space. It is released when the cuticle ruptures.