Journal
PLANT BIOLOGY
Volume 15, Issue 5, Pages 910-918Publisher
WILEY
DOI: 10.1111/j.1438-8677.2012.00695.x
Keywords
Cyathium protogyny; homeostatic mechanism; hummingbird preference; nectar; sexual phases
Categories
Funding
- Erasmus-Mundus interchange programme
- CNPq
- Universidad Nacional de Cordoba (SECyT-UNC)
- CONICET
Ask authors/readers for more resources
Floral sexual phases can differ in nectar production and might be under selective pressure by pollinators. We studied Euphorbia tithymaloides, which has inflorescences that are initially female and then hermaphroditic. Volume and concentration of nectar were measured in both stages. Nectar production and the effect of extractions were determined using sets of bagged inflorescences; inflorescences in the hermaphroditic phase had higher values of nectar concentration, volume and sugar mass than inflorescences in the female phase. Nectar resorption was detected in senescent inflorescences. To test for homeostatic nectar regulation, artificial nectar was added and the response assessed after 24 h. The experiments showed that concentration and sugar mass are regulated within a narrow range, and the homeostatic points differ between the two sexual phases. These differences in nectar can be detected by hummingbirds, which prefer the female stage. Resorption and secretion seem to be part of a homeostatic mechanism by which nectar attributes are maintained to optimise sugar recovery.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available