Reddish spring colouring of deciduous leaves.pdfVIP

ORIGINAL PAPER Reddish spring colouring of deciduous leaves: a sign of ecotype? Kari Taulavuori ? Henna Pihlajaniemi ? Satu Huttunen ? Erja Taulavuori Received: 12 February 2010 / Revised: 8 September 2010 / Accepted: 23 September 2010  Springer-Verlag 2010 Abstract Several deciduous woody plant species produce anthocyanins during leaf development in spring and again during leaf senescence in autumn. The leaves of Betula pendula Roth (silver birch) commonly exhibit transient reddening in juvenile leaves under northern growing con- ditions, with the intensity of the red colour varying among individual trees. The objective of our study was to test the hypothesis that the accumulation of foliar anthocyanins during spring in leaves of B. pendula is an ecotypic response. Chlorophyll fluorescence ratio (Fv/Fm), leaf reflectance and anthocyanin concentrations were measured, in relation to phenology in spring, summer and autumn from birches used for landscaping with either red or green- emergent leaves. The results suggest that (1) the trees with green- or red-emergent juvenile leaves represent different populations, and (2) that the red-emergent leaves senesced earlier, indicating that (3) trees with red-emerging leaves belong to a more northern ecotype than the trees with green-emerging leaves. The role of anthocyanin synthesis in a northern radiation environment is discussed. Keywords Anthocyanins  Betula pendula  Chlorophyll fluorescence  Ecotype  Leaf reflectance Introduction The leaves of deciduous trees sometimes display transient red colouring before they reach maturation. The phenom- enon occurs in a variety of environments, including tropical and equatorial latitudes (Coley and Barone 1996). At high northern latitudes, this phenomenon is especially observed when unusually warm spring days are followed by a cooler period. The red colour-forming pigments are anthocyanins, which play a variety of roles in plants, such as protection against solar UV and visible r