Bark anthocyanin levels differ with location in cultivars of red maple

Abstract

The objective of this study was to determine differences in the bulk anthocyanin content of bark tissue of container-grown red maple (Acer rubrum L. and Acer xfreemanii E. Murray) at two Georgia locations with different environmental conditions. Rooted cuttings and tissue-cultured plantlets of eight cultivars were grown in either Blairsville or Tifton, Ga. [U.S. Dept. of Agriculture (USDA) Hardiness Zones 6b and 8a; American Horticultural Society (AHS) Heat Zones 5 and 8, respectively], from June 1995 until Dec. 1996. Bark tissue from twigs of trees grown in Blairsville was visually redder and contained more total anthocyanin than did that of trees grown in Tifton. Levels of total anthocyanins were higher (P = 0.0007) at Blairsville (0.087 mg·g-1, N = 48) than at Tifton (0.068 mg·g-1, N = 47). At both locations the levels were highest in 'Landsburg' ('Firedance'(TM)), followed by 'Franksred' ('Red Sunset'(TM)) and 'October Glory'. This is the first report to quantify anthocyanin differences in bark tissue of container-grown trees. Cooler nights in Blairsville might have contributed to increased coloration by reducing respiratory losses, thus leaving more carbohydrates available for pigment production.