Growth rate and carbohydrate metabolism of potato tubers exposed to high temperatures

TLDR: In this article, the effect of high tuber temperature (30 °C) on the growth rate and carbohydrate metabolism of tubers was studied with three cultivars differing in heat tolerance, and it was concluded that high soil temperatures may decrease starch content of potato tubers directly by inhibition of the conversion of sugars into starch.

Abstract: The effect of high tuber temperature (30 °C) on the growth rate and carbohydrate metabolism of tubers was studied with 3 cultivars differing in heat tolerance. Subjecting individual tubers to 30°C for 6 days caused cessation of tuber growth. During this period, non-treated tubers (20°C) on the same plant increased in volume. At 30°C, incorporation of14C-labelled assimilates into the ethanol-insoluble fraction (mainly starch) as well as the starch content was significantly reduced. In contrast, the incorporation of14C-labelled assimilates into the sugar fraction was not affected by high tuber temperature. At 30°C the activity of some of the enzymes involved in starch metabolism was depressed. Varietal differences in responses of tuber growth rate and carbohydrate metabolism to high tuber temperature were insignificant. From these preliminary results it is concluded that high soil temperatures may decrease starch content of potato tubers directly by inhibition of the conversion of sugars into starch.