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

CHALCOFF VANINA RUTH; AIZEN MARCELO ADRIÁN; GALETTO LEONARDO

ANNALS OF BOTANY

Oxford University Press

Año: 2006 vol. 97 p. 413 - 421

0305-7364

Background and Aims. Floral nectar concentration and chemical composition of 26 plant species native to the temperate forest of southern South America are reported and the relationship with their flower type are evaluated. Methods. Nectar concentration was measured with a hand refractometer and sugar composition was analysed by gas-liquid chromatography. Plant species were classified into flower type categories based not only on floral features but also on data from the literature and field observations on their pollinators.Key Results. Most nectar data are new reports at the generic and/or specific level. Plant species with more than one population studied showed significant amounts of among-population variation in nectar sugar concentration and composition. Results showed a weak relationship between nectar traits and flower type. Many species showed nectars with 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 types or with plant taxonomic membership, and (b) different populations of the same species showed large variability in sugar composition, our results suggest that other factors (e.g., historical and environmental) could be involved in determining the sugar composition of the highly endemic plant species from this region.