ISHS Acta Horticulturae 545: V International Protea Research Symposium
DRY MASS ACCUMULATION AND CARBOHYDRATE ALLOCATION IN SUCCESSIVE GROWTH FLUSHES OF PROTEA CULTIVAR SYLVIA AND PROTEA CULTIVAR CARDINAL SHOOTS |
| Authors: | H.B. Hettasch, K.I. Theron, G. Jacobs |
| Keywords: | total sugar content, source-sink relationships |
| Abstract:
Whole shoots of Protea cv. Sylvia (P. eximia x P. susannae) and Protea cv. Cardinal (P. eximia x P. susannae) plants were sampled at the conclusion of each successive growth flush over a period of one growing season. The dry mass of leaves and stems of each flush was measured separately and a sample analysed for total sugars and starch concentrations. Total dry mass of both stems and leaves of ‘Sylvia’ and ‘Cardinal’ remained similar during growth of the spring and first summer flushes and then increased significantly during the formation of the second summer flush and the autumn flush. The concentration of carbohydrates (total sugars and starch combined) in the leaves and stems of the whole shoot, increased significantly from one flush to the next, up to and including the second summer flush. The concentration of carbohydrates in the leaves of the whole shoot was significantly reduced after the winter, while in the stems the concentration remained similar. Total sugars and starch concentrations in the leaves of both ‘Sylvia’ and ‘Cardinal’ were significantly higher than in the stems in all the flushes. | |
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