J. Wiebel et al., CARBOHYDRATE-LEVELS AND ASSIMILATE TRANSLOCATION IN MANGOSTEEN (GARCINIA-MANGOSTANA L), Gartenbauwissenschaft, 60(2), 1995, pp. 90-94
Diurnal variations in soluble sugar and starch levels in mature leaves
of two-year-old mangosteen (Garcinia mangostana L.) seedlings with im
mature, semi-mature, and mature terminal flushes were studied. Glucose
, fructose, sucrose, and starch concentrations in leaf extracts increa
sed significantly after midday, reaching a maximum at 1800 hours, rega
rdless of the ontogenetic stage of the terminal flush. A time course s
tudy of C-14-assimilate translocation and distribution in unbranched s
eedlings with semi-mature terminal flushes showed that more than 49% o
f C-14 activity was exported from the source (pulsed) leaf within 1 da
y, with less than 16% remaining in the source leaf after 8 days. Immat
ure flushes attracted more than 75% of C-14 within 3 days. When the sh
oot system was non-flushing 53% of the total C-14 remained in the sour
ce leaf after 3 days, with stems and roots exhibiting the strongest si
nk activity. High translocation rates in flushing and non-flushing see
dlings observed in this study suggest that assimilate production rathe
r than translocation may be a major factor limiting the growth of mang
osteen seedlings.