Abstract
Three ecotypes of tomato (Japanese, Ogata Zuiko; North European, Money Maker; South European Roma) were grown under 25/15, 25/22.5 and 25/30°C day/night temperature regimes. Photo-assimilate translocation at 0, 6 (end of day) and 18 (end of night) h after the photosynthetic 13CO2-feeding for 1 h were examined. At 0 h, main labeling was upper leaves but in fruit and root, considerable and a little labeling, respectively, was observed. The highest 13C fixation occurred at 25/22.5°C in Ogata Zuiko and 25/15°C in Roma. In Money Maker, a high value was observed in each plot. At 6 h, 13C in leaf fraction decreased rapidly, and a slight and a remarkable increase of 13C was observed in root and in fruit. 13C import to fruit was large at 25/22.5 and 25/30°C in Ogata Zuiko and 25/15°C in Roma, and that in Money Maker exceeded the other two cultivars in every plot. At 18h, 13C in leaf and stem decreased further and in root, increased. Fruit increased 13C successively at 25/22.5°C. Money Maker was less sensitive to temperature and had high capacity in every plot, Roma was heat sensitive, and Ogata Zuiko was medium of the two cultivars.
