[Ultrastructural observation of banana shoot-tip cell during cryopreservation by vitrification].

Excised shoot-tips produced from banana plants belonging to cv. Guangdong No.1 (ABB group) were cryopreserved successfully by vitrification using the PVS2 solution. Ultrastructural of banana shoot-tips cells was also observed by using electron micryoscopy (TEM). The results showed that the plasmolysis became more and more severe during the course of dehydration. Cells were mainly damaged during the freezing and thawing process. Most cell protoplasts condensed, and cell organelles, cell membranes and nucleus envelopes were lethally injured after cryopreservation. But only a few cells located in the meristematic dome arose reversible process although their structures were varied. They could survive and regenerate plantlets after freezing conservation.