ISHS Acta Horticulturae 81: Symposium on Winterhardiness in Woody Perennials
APPLE STEM CALLUS FROST TOLERANCE AND GROWTH MODIFICATION BY ADDING SORBITOL AND SOME GROWTH REGULATORS TO THE MEDIUM |
| Authors: | J. Pieniazek, T. Holubowicz, B. Machnik, M. Kasprzyk |
| Abstract:
It was found that replacing sucrose with sorbitol in the basic Murashige-Skoog /MS/ medium, a more prolific growth of the apple stem callus was obtained; and it increased its tolerance to -12.5°C, and -13.5°C. The callus grown on the medium with 3, 5, 8 % sucrose and 3 % sorbitol was killed when exposed to -15°C, whereas 50 % of that grown on 8 % sorbitol had survived. In the spring of 1977 the first experiments on the effect of growth regulators /CCC, GA, Alar, ABA and Ethrel at conc. of 20 ppm/ on the frost tolerance of apple stem callus were made. It was found that the addition of CCC and Alar to the medium inhibited the growth of the callus /figure 1/. Preliminary results with freezing the callus had indicated that ABA, Ethrel and Alar increased slightly the frost tolerance of apple callus but the re-growth of the callus in different flasks varied greatly, and the fresh weight of the callus could not be used as a reliable index of viability after temperature stress. The regeneration potential of individual cells was studied in Petri dishes on semi-solid agar. It became evident that small, young cells survived the exposure to -15°C better than the large, older cells /figure 2/. In the future the experiments with above growth regulators will be repeated, and the regeneration potential after freezing of the dissociated callus cells studied. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
