IS DESICCATION THE CAUSE OF THE POOR SURVIVAL RATE IN THE ACCLIMATIZATION OF MICROPROPAGATED PRUNUS CERASUS L.?

J.A. Marín, R. Gella
Desiccation has been pointed out as one of the main causes of poor survival in acclimatized plants. However, the study of a number of factors affecting desiccation questions it.

Stomatal structure and functioning as well as cuticular structure and transpiration were studied on different types of leaves from in vitro and acclimatized plants of a micropropagated cherry rootstock with a low survival rate during acclimatization. Stomata of leaves from in vitro grown plants were shown to close, and this closure was faster with acclimatization. Moreover, in vitro leaf stomata had a similar structure to that of acclimatized plant leaves, although guard cells were richer in both starch and chloroplasts. Cuticular structure of in vitro leaves was similar to that of acclimatized plant leaves, but thinner, what could explain the greater transpiration rate found. Water transport through in vitro plant roots was also studied showing an effective transport. Anatomical studies of the root stem zone revealed no discontinuities in the xylem vessels.

Changes in the leaf structure were observed with acclimatization. In vitro plant leaves had a shade-leaf structure with a small mesophyll cell density and one palisade cell layer. However, after acclimatization, these leaves showed sun-leaf characteristics as a higher cell density and a double palisade cell layer.

Structural and functional evidence presented here do not support the idea of desiccation as being the cause of poor survival in the process of acclimatization. This point agrees with the fact that survival rate raised from 15 to 85 per cent by changing the environmental conditions, and is further supported by the fact that death of micropropagated Prunus cerasus plants during acclimatization started 15 days after transfer to soil.

Marín, J.A. and Gella, R. (1988). IS DESICCATION THE CAUSE OF THE POOR SURVIVAL RATE IN THE ACCLIMATIZATION OF MICROPROPAGATED PRUNUS CERASUS L.?. Acta Hortic. 230, 105-112
DOI: 10.17660/ActaHortic.1988.230.10
https://doi.org/10.17660/ActaHortic.1988.230.10

Acta Horticulturae