You are here

Within-plant distribution of phenolic glycosides and extrafloral nectaries in trembling aspen (Populus tremuloides; Salicaceae)

TitleWithin-plant distribution of phenolic glycosides and extrafloral nectaries in trembling aspen (Populus tremuloides; Salicaceae)
Publication TypeJournal Article
Year of Publication2010
AuthorsYoung, B, Wagner, D, Doak, P, Clausen, T
JournalAmerican Journal of Botany
Volume97
Pagination601–610
Abstract

Expression of foliar secondary compounds and extrafl oral nectaries (EFNs) within the same leaves may be incompatible if secondary compounds repel benefi cial insects that might otherwise be attracted to EFNs. This study examined the within-plant distributions of phenolic glycosides and EFNs in trembling aspen, Populus tremuloides , and their relationships to herbivore damage. Populus tremuloides expresses extrafl oral nectaries (EFNs) on a subset of its leaves. We studied short and tall naturally occurring aspen ramets across multiple sites in interior Alaska. Contrary to our expectations, foliar phenolic glycoside concentrations were approximately 30% greater on leaves bearing EFNs than on leaves without EFNs. The mean concentration of foliar phenolic glycosides in short ramets was nine times that in tall ramets. Phenolic glycoside concentration was negatively related to leaf mining damage by Phyllocnistis populiella (Lepidoptera; Gracilliadae) at concentrations greater than 27 mg/g, whereas the presenceof EFNs was unrelated to mining damage. The positive association of chemical defensive compounds and EFNs in leaves suggests that, for species with variation in EFN expression, negative correlations between herbivory and EFN expression may arise indirectly from associated effects of other, correlated types of defense.

DOI10.3732/ajb.0900281
Username Tag: