Abstract
Translocation and distribution of photo-assimilates in strawberry plants were studied by pules-feeding 14CO2 at different developmental stages of inflorescence.
1. After feeding the largest leaf at the fruit coloring stage, there were distinguished a rapid phase of about 6 hours and a subsequent slow phase in 14C export on the basis of 14C recovered. The current export was terminated about 16 hours after feeding with a percentage value of 50, about 90% of which was distributed in the berries.
2. When all the leaves were fed, the total export to plant parts other than leaves increased from around 20% after feedings at and before flowering to 52% after feeding at the coloring stage of the 14C exported, about 40% was found in the roots and only 20% in the flowers after feedings at and before flowering. After later feedings, the distribution to the roots decreased and that to the berries increased gradually, reaching 86% at the coloring stage.
3. Within an inflorescence, distribution to the receptacle increased from 70% after feeding at the budding stage to 89% after the coloring stage, although it decreased to 30% temporarily after feeding at the growing stage. Correspoding to this decrease, distribution to the achenes increased to 68% but soon decreased to 9% after feeding at the coloring stage.
4. Within an inflorescence, there was recognized competition for 14C assimilates among flowers; this was especially true between the primary and tertiary flowers.
5. In individual flowers, sink activity decreased, though temporarily, near flowering. This flowering of sink activity seemed to be intrinsic, and should be distinguished from lowering by competition (with other flowers).
