A comparative study of translocation of assimilated(14)C from leaves of different species.

Translocation of assimilated(14)C from the leaves of different species varied both in the rate of export and in the total percentage moved out. Those species which are known to have high photosynthetic rates, such as the tropical grasses sorghum and millet, exported 70% or more of the assimilated(14)C during the first 6 h after assimilation, compared to values of 45 to 50% for tomato, castor bean,Nicotiana affinis and soybean.The compounds in which the(14)C was retained in the leaves varied from species to species. Except for castor bean only small amounts were retained in sucrose, with generally much higher amounts in fructose, glucose and malic acid. Most of the(14)C was retained in the ethanol-insoluble fraction.