Effects of aeration using various tube closures on growth and anatomy of Swainsona formosa (G.Don) J Thomson aventitious shoot cultures

The development of adventitious shoot of Swainsona formosa was affected by the permeability of tube closure. Increasing permeability of tube closure decreased vitrifica¬tion, but at the same time reduced shoot number and callus width. Length and vigour of shoots increased with the increases in tube closure permeability. Anatomical study of vitrified shoots found abnormal tissue between the two guard cells in the stomata, a low density of stomata, unclear differentiation of structural components of the meristem, and large starch granules and reduction in numbers of thylakoid stacks in the chloroplasts when compared to in vitro normal tissues. Key Words: vitrification, Swainsona formosa, tube closure Vitrification, Swainsona Formosa, Tube Closur