Cuticular wax linear alkanes in leaves of Populus alba, Populus deltoi- des (Salicaceae), Robinia pseudoacacia (Fabaceae), Ulmus pumila (Ulmaceae) and Fraxinus americana (Oleaceae) from Tandil, Buenos Aires, Argentina

Abstract

Mature leaves of adult individuals of  Populus alba,  Populus deltoides,  Robinia pseudoacacia, Ulmus pumila and Fraxinus americana from the University Campus, Tandil, Buenos Aires, Argentina (37° 19’S, 59° 08’W) were collected on February 2004. The cuticular wax was extracted, purified, and the content and relative proportion of odd-carbon numbered n-alkanes (C₂₃→C₃₅) was quantified by capillary gas-liquid chromatography. Total concentration of  n-alkanes (mg/kg DM) were  P. alba (6935) > Robinia (1571) > P. deltoides (1379) > Ulmus (880) > Fraxinus (467). Most abundant n-alkanes in all species were C₂₇ and C₂₉ accounting for 10-51% and 35-76% of total, respectively, except Fraxinus where most abundant were C₂₉ and C₃₁ accounting for 31% and 41% of total, respectively. P. alba and P. deltoides differed not only in total concentration of all n-alkanes but also in relative proportion of C₂₇ and C₂₉, being C₂₉ the most abundant in the latter species (76%) as well as in Robinia (75%). The occurrence of even-carbon numbered n-alkanes was either undetectable or very low in all species in general, except for C₂₆, C₂₈ and C₃₀, the latter being prominent in Fraxinus.