Relation between the vascular system and photosynthate translocation pathways in tomato plants

The relation between the vascular system and the photosynthate translocatio n pathway was investigated in main stems, sympodiums, and inflorescences of tomato plants. The plants had the Ist inflorescence on the main shoot with 9 leaves, and the 1st, 2nd and 3rd lateral shoots with 3 leaves from each terminal node. The shoot alternated right- and left-handed phyllotaxis. There were 4 vascular bundles in the hypocotyl and 8 vascular bundles in th e main stem and sympodiums. Four vascular bundles were located at the base of the Ist inflorescence. Two were connected to the 7th leaf and to the 2nd or 4th flowers; the other two were connected to the 8th leaf and the 1st o r 3rd flowers. When (14) CO2 was fed to 7th or 8th leaf, the highest radioactivity was rec overed in the internode just below the treated leaf among the internodes on the main stem and sympodiums. In each internode, particularly strong radio activity was recovered in 3 of 8 vascular bundles. Among the pedicels in th e Ist inflorescence, the highest radioactivity was recovered in the Ist and 3rd ones when the 8th leaf was treated, and in the 2nd and 4th pedicels wh en the 7th leaf was fed with (14) CO2.