HISTOLOGICAL STUDIES ON GINGER RHIZOME (ZINGIBER OFFICINALE Rose.)

Abstract

The vascular pattern of the underground rhizome of ginger was studied at different stages of development. The internal structure of rhizome showed an inner zone and an outer zone, separated by intermediate layers . Collateral vascular bundles were scattered and more in inner zone. The xylem vessels are with scalariform thickenings and scalariform perforation plates. Libriform fibres or rarely fibre tracheids are met with. The phloem consisted of sieve tubes companion cells, parenchyma and fibres. Oil cells and canals are many. Numerous starch grains, varying in their shape, size and number, were present in both s i~es of intermediate zone. The rhizome enlargement is by the activity of : (i) primary thickening meristem and procambial cells in the ground parenchyma, (ii) the actively dividing ground parenchyma and (iii) the secondary thickening meristem in which the fusiform and ray initials are discrete. Th.e presence of cambium like layer was an important feature found in ginger.