INVESTIGADORES
GLEISER gabriela Laura
artículos
Título:
Pollinator type and secondarily climate are related to nectar sugar composition across the angiosperms
Autor/es:
CHALCOFF, V. R.; GLEISER, G.; EZCURRA, C.; AIZEN, M. A.
Revista:
EVOLUTIONARY ECOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2017 vol. 31 p. 585 - 602
ISSN:
0269-7653
Resumen:
Pollinators are important agents ofselection on floral traits, including nectar sugar composition. Although it iswidely assumed that the proportion of sugars (mainly sucrose, glucose andfructose) in nectar reflects pollinators? physiological limitations and digestiveefficiency, the relative impact of pollinators and abiotic factors on nectarsugar composition, as well as the generality of these associations across theangiosperms, remain unknown. We compiled data on nectar sugar composition for >1000 plant species,along with information on flower visitors, plant growth form and latitudinalclimatic zone, to provide the first comprehensive assessment of correlates ofvariation in sugar nectar composition in the angiosperms. After assembling aphylogeny linking all species in the dataset, we estimated the amount ofphylogenetic signal in the percentage of sucrose and, by applyingphylogenetically-informed multiple regressions, we evaluated whether nectar compositionwas influenced either by the main pollinator group, plant growth form, or latitudinalclimatic zone. The relative importance of each of these factors was then assessedthrough model selection based on Akaike information criteria and deviance partitioninganalysis. Nectar was dominated by sucrose in 56.8% of all the species, glucose in16.7%, and fructose in 5.5%. Nectar in the remaining species was characterizedby similar proportions of the three sugars. Variation in the proportion ofsucrose was highest (~70%) at theintrafamily level, and had a significant but low phylogenetic signal, which partiallyreflects phylogenetic conservatism of the pollinator niche. After controllingfor phylogenetic effects, the proportion of sucrose was mainly related topollinator type and secondarily to climate. Accordingly, this study indicatesthat nectar sugar composition shows high evolutionary lability and itsvariation reflects plant-pollinator associations.