Effect of Water Deficit on Translocation of Carbohydrate in Solanum tuberosum

Abstract

The effect of drought on the fixation and translocation of labelled carbon in the potato (S. tuberosum) was examined. Low leaf water potentials resulted in a decrease in translocation which was proportional to the decline in net photosynthesis, irrespective of whether tubers were absent or present. The ratio of ¹⁴C entering polysaccharides to that in ethanol-soluble compounds markedly decreased in droughted leaves. These data suggest that the decrease in growth of tubers under conditions of water deficit can be ascribed to direct effects on tuber growth and photosynthesis but not to interference with vein loading or velocity of transport of photosynthate.