MOR, Y., Department of Ornamental Horticulture, Hebrew University, Rehovot, Israel
HALEVY, A.H., Department of Ornamental Horticulture, Hebrew University, Rehovot, Israel

Movement of 14C‐assimilates from young and mature leaves to young rose shoots (Rosa hybrida cv. Marimba) was examined in two developmental stages. In the first stage after bud breaking the young shoot, especially its tip, depends for its supply of assimilates mainly on the mature foliage. At this stage young leaves are powerful sinks and retain 97% of their own photosynthates. The translocated 3% move mainly to the roots. At a later stage, just after the appearance of the flower bud, most of the leaves on the shoot become a source. The upper leaves supply assimilates to the flower bud and to the upper part of the stem. The 14C‐assimilates from the lower leaves move in two directions, the larger part being directed downward. Copyright © 1979, Wiley Blackwell. All rights reserved