4.3. Uptake and distribution of radioactive compounds from 14C
sucrose feeding to buds of different sizes
The most significant differences in radioactivity were observed
in the anther and the filament of the smallest buds (1.3 g) over the
course of the measurements. This might indicate that the anther in
the young and developing buds is functioning as a strong sink since
most of the radioactivity was recovered in the anther, which may
be in a growth phase at that time (Clement ˇ et al., 1996). Translocationof
14Csucrose ormetabolites to the anthers was inhibited when
bud abscission was artificially induced,thus resulting in 14C sucrose
or metabolic derivatives of sucrose accumulated in filaments and
ovary and style. If 14C sucrose can be translocated from the cut
end of the pedicel to the anthers in the lilies at a rate of 4–6 cm
per minute as reported in sugarcane leaves and stems (Hatch and
Glasziou, 1964), 14C sucrose can reach the anthers in less than a
minute or two, and it supports the idea thatlimited sucrose translocation
to the anther may play a critical role in inducing flower bud
abscission. This clearly suggests that development of the anthers
in small buds (1.3 g) is at a critical stage which must be determined
in relation to future pollen development. The critical weight
of buds may range from 1.03 g to 1.61 g or about 1–2 cm in length.