EFFECTS OF DIURNAL TEMPERATURES AND LEAF POSITION ON THE TRANSLOCATION AND DISTRIBUTION OF C-14 PHOTOSYNTHATES IN FRUITING STRAWBERRY CV MORIOKA-16

Strawberry plants cv. Morioka-16 were grown under 9 day/night temperat ure regimes from anthesis. (CO2)-C-14 was administered to the uppermos t leaf on the main crown of the plants and kept under each temperature regimes for 18 hr after which the distribution of C-14 was determined . Regardless of the diurnal temperatures, the percentage of C-14 trans located in the terminal inflorescence increased as the fruit grew and matured. Of the labelled carbon recovered, 25%was partitioned to the i nflorescence at anthesis, whereas 60 approximately 80% was imported by the ripening fruit. The result suggests that temperature has a large effect on the growth process of the inflorescence, but it does not inf luence the distribution pattern of photosynthates while the infloresce nce growing. The distribution pattern of C-14 depended upon the positi on of the leaf which was administered the label. When the uppermost le af on an axillary branch was fed, the percentages of C-14 distributed in the branch inflorescence and secondary branch subtended by the fed leaf were greater compared to the case the uppermost leaf on the main crown was fed. These data suggest that the rosetted strawberry plant h as a similar source-sink relationship with respect to photosynthate as do other herbaceous species.