Cytohistological Observation of Callus and Adventitious Buds of Casuarina cunninghamiana Miq. in vitro

Abstract:

In order to understand the cytohistology of Casuarina cunninghamiana callus, cell division, callus differentiation and adventitious bud regeneration were studied under scanning electron microscope and paraffin sections. The results showed that parenchyma cells in the wound started dedifferentiation in the callus induction medium. After cultured for one week, callus were induced at the explant wound, and embryonic callus was formed. Bud primordium was induced from surface cells after two weeks. After culturing for a further four weeks, embryonic bud primordium became more increasely visible, and gradually differentiated to become adventitious bud. After another six weeks, most of the adventitious buds have proliferated and differentiated, and some developed to shoots. It was confirmed that the regeneration of C. cunninghamiana could be achieved through embryoid callus differentiation, it would provide basis for establishment of efficient regeneration system in C. cunninghamina.