Influence of moisture stress during growth on14CO2 fixation and translocation inSolanum tuberosum L.

Moisture stressing of potato plants resulted in reduced¹⁴CO₂ fixation and translocation of labelled photosynthates from leaves to tubers. A majority of the label was recovered in the sugar fraction of both leaves and tubers. The amount of labelled¹⁴C recovered in the organic acid fraction of tubers of normally irrigated plants was significantly higher than in tubers which had been moisture stressed. In the other fractions, the differences were not significantly different. Injection of uniformly labelled sucrose into the basal portion of attached tubers of stressed and non-stressed plants showed greater translocation of labelled carbon by tubers of stressed plants from basal to the apical portion and also into the stems as compared to non-stressed plants.