Morphological Observations of Chrysanthemum Shoot Tips Cultured after Cryoprotection and Freezing

Abstract

Microscopic examination of cryopreserved shoot tips of chrysanthemum (Dendranthema grandiflorum KITAM. (RAMAT.)) revealed that only a small part of the shoot tip frozen in liquid nitrogen survived after thawing. Many different types of recovery were observed. Survived shoot tips showed two ways of shoot regeneration. In one, a small bump with smooth surface on a leaf primodium developed into a shoot. In another case, green spots appeared on the rough surface of the callus and these developed into a shoot. Treatment of dimethyl sulfoxide (DMSO) caused the leaf developed from shoot tips to become abnormal.