CARBOHYDRATE STORAGE AND RE-MOBILIZATION IN ASPARAGUS: STUDIES USING DRY WEIGHT CHANGES, C-14 AND HIGH PRESSURE LIQUID CHROMATOGRAPHY

Expanded, non-senescent fern were exposed to ¹⁴CO₂ for one day in mid-summer, late summer or early autumn.
Results from this procedure indicated that an abrupt change in partitioning of carbon between fern and crown (rhizome plus storage roots) occurred during mid-summer.
It was suggested that the environmental signal for this change in partitioning may be decreasing daylength.
The use of ¹⁴C also enabled the pattern of carbohydrate accumulation in the crown over time to be easily measured.
Soluble carbohydrates in the crown were analyzed by high performance liquid chromatography (HPLC). Dry weight and fructans in the crown decreased slowly during winter and spear harvest but rapidly during fern establishment.
In contrast decline in previously incorporated ¹⁴C label was almost as rapid during the harvest period as it was during fern establishment, suggesting that spear growth utilized specific pools of labeled carbohydrate with high specific activity.
Evidence based on specific activity of radioactivity in different parts of the crown suggested that specific roots might preferentially supply the spears.
Spear growth may also be limited by the rate at which long chain fructans are hydrolyzed, as HPLC analysis of fructans indicated that short chain fructans were depleted more rapidly than they were replenished from long chain fructans during spear harvest, but not during fern establishment.

IX International Asparagus Symposium

D.J. Woolley, A.R. Hughes, M.A. Nichols

partitioning, sink, fructans, daylength

https://doi.org/10.17660/ActaHortic.1999.479.42