EFFECT OF TEMPERATURE ON CARBOHYDRATE-METABOLISM IN POTATO PLANTS

The effect of temperature on partioning of newly fixed C-14 between the various carbohydrate fractions was studied in different plant organs of three potato varieties. Incorporation of C-14 into starch in the tubers was reduced at high temperatures, but the amount of labelled sucrose increased. In all varieties the incorporation of C-14 into the cell wall components in the apex of the plant and in the stem, as well as its incorporation into starch in the stem, was increased at high temperatures. The variety Norchip, which was found to be less sensitive to high temperature as indicated by carbon translocation to the tubers, was found to be less affected also in terms of C-14 incorporation into starch in the tubers. We suggest that high temperature affects carbon metabolism in the various plant organs and the resulting changes are associated with the change in the partitioning of assimilates between these organs.