Nectary and Nectar Features: Occurrence, Significance, and Trends in Bignoniaceae

GALETTO L

The Journal of Plant Reproductive Biology

The Society of PRB

Lugar: Agra; Año: 2009 vol. 1 p. 1 - 12

The variety of pollination strategies present in the Bignoniaceae makes the family ideal for comparativestudies of the evolution of floral features. Six flower and nectar parameters were recorded fromliterature for 50 species (nectar concentration, volume per flower, and amount of sucrose, corollalength, and nectary size and stomata number). Comparisons were made between two pollinator guildsand two tribes. Significant differences were not detected between the tribes Tecomeae and Bignonieae(n= 21 and 16 species respectively). On the other hand, bee-pollinated species presented a highernectar concentration and a lower nectar volume per flower than bird-pollinated species (n=29 and 8species respectively). Results showed that some nectar features are correlated with the differentpollinator guilds and may indicate nectar adaptations by flowers to their pollinators. Floral structuraltraits seem to be more conservative than nectar features because the lack of significant differencesbetween tribes and pollinator guilds at both the species and the genus level. These patterns suggestthat pollinators would be involved in primary changes on nectar traits and later, in a second evolutionarystep, on structural floral modifications.