Nectar concentration and composition of 26 species from the temperate forest of South America

CHALCOFF, V.R, M.A. AIZEN Y L. GALETTO

ANNALS OF BOTANY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2006 vol. 97 p. 413 - 421

0305-7364

Background and Aims Floral nectar concentration and chemical composition of 26 plant species native to thetemperate forest of southern South America are reported and the relationships with the flower type are evaluated. Methods Nectar concentration was measured with a hand refractometer and sugar composition was analysed bygas?liquid chromatography. Plant species were classified into flower type categories based not only on floral featuresbut also on data from the literature and field observations on their pollinators. Key Results Most data on nectar are new reports at the generic and/or specific level. Plant species in which morethan one population was studied showed significant among-population variation in nectar sugar concentration andcomposition. Results showed a weak relationship between nectar traits and flower type. Many species had nectarcontaining 50% or more sucrose (17 of 26 species), independent of the main pollinator. Conclusions Considering that (a) nectar characteristics did not show a clear association with different flower typesor with plant taxonomic membership, and (b) different populations of the same species showed large variability insugar composition, the results suggest that other factors (e.g. historical and environmental) could be involved indetermining the sugar composition of the highly endemic plant species from this region.