EFFECT OF GALACTOSE AND GALACTOSE CONTAINING SUGARS ON EMBRYOGENESIS IN CITRUS CALLUS

Studies on factors controling embryogenesis were carried out with Citrus callus originally obtained from unfertilized ovules and nucelli of the ‘Shamouti’ orange Citrus sinensis Osb.
The subcultured callus is habituated and completely independent from exogenous auxin and cytokinins.

Non-embryogenic and embryogenic callus lines were selected and maintained and serve for comparative studies.

We established befor that aging of tissue, sucrose omission, gamma-irradiation and several inhibitors of auxin synthesis greatly increase embryogenesis while this is inhibited by auxins and cytokinins.
We assume that culture conditions and treatments lowering the auxin level induce embryogenesis in this habituated callus.

It was recently reported that galactose and galactose containing sugars inhibit auxin synthesis.
These sugars were found to be very potent in inducing embryogenesis in Citrus callus.
We shall report on these effects and on interactions of galactose with sucrose and auxin regarding embryogenesis and growth of callus.
The possible mechanism of action of galactose and bearing of our findings for other cell and tissue culture systems will be discussed.

Symposium on Tissue Culture for Horticultural Purposes

J. Kochba, P. Spiegel-Roy, S. Saad, H. Neuman

https://doi.org/10.17660/ActaHortic.1977.78.23