Temporal and Spatial Glucose and
Starch Partitioning in Live Oak
Tomas Martinez-Trinidad, W. Todd Watson, Michael A. Arnold,
and Leonardo Lombardini
Abstract: Carbohydrate translocation, which follows anatomical and developmental patterns, is ruled by source-sink relations where energycontaining compounds are moved from sources of production to sinks of utilization. Seasonal carbohydrate concentrations in various tree parts were measured and compared in 10 cm (4 in) trunk diameter live oaks (Quercus virginiana P. Miller). Tissue samples from roots, trunks, twigs and leaves were collected from three-year-old field-grown trees on four dates throughout the 2005–2006 seasons. Laboratory analyses of glucose and starch were performed, and values were compared and contrasted according to sample location and time of year. Glucose levels were significantly higher in leaves during the winter (P = 0.001), while starch concentrations were significantly higher in root and trunk tissues during the spring and winter assessments (P = 0.001). Carbohydrate concentrations varied among tissues sampled within the tree. This study provides valuable information on the spatial and temporal partitioning of energy reserves, glucose and starch, in live oak so that arborists will have a better understanding of tree vitality, and the effects and environmental impacts of arboricultural treatments.
Keywords: Carbohydrates; Quercus virginiana; Source-Sink Relations; Sugar.