Caracterización y variación espacio-temporal del néctar floral en Anarthrophyllum desideratum (Fabaceae), un arbusto ornitófilo de la estepa patagónica.

PAIARO, V.; OLIVA, G.; COCUCCI A. A.; SÉRSIC, A.N.

BOLETíN DE LA SOCIEDAD ARGENTINA DE BOTáNICA

SOCIEDAD ARGENTINA DE BOTÁNICA

Lugar: Córdoba; Año: 2012 vol. 47 p. 375 - 387

0373-580X

Summary Characterization and intra-specific variation of floral nectar in Anarthrophyllum desideratum (Fabaceae), an endemic shrub of the Patagonian steppe pollinated by Passerine birds. Anarthrophyllum desideratum (DC) Benth. is an endemic shrub of the Patagonian steppe pollinated by Passerine birds. At the present study, we characterize the volume, concentration and sugar composition of floral nectar, and analyze their temporal and spatial variation at different levels (among plants, among populations and among ecological regions). By gas chromatography, we determined the proportion of glucose, fructose and sucrose. Nectar showed, in average, a volume of 8.1 µl, and a concentration of 28 %, and was dominated by hexoses, in line with expectations according to the species floral syndrome. Concentration was positively associated with sucrose percentage. Nested analyses of variance revealed that all characters varied among populations, and most of them varied among ecological regions. Volume and concentration also differed among individuals within populations. In all cases, differences among populations accounted for most of the variability. Nectar volume and concentration varied between years, while sugar composition (proportions) remained constant. The results suggest that biotic or abiotic factors acting at a local scale could affect the variation in nectar attributes of A. desideratum.