Floral nectar composition in different subgenera of Argentinian Passiflora species.

AMELA GARCÍA, M. T. & GOTTSBERGER, G.

PLANT SYSTEMATICS AND EVOLUTION

Springer

Lugar: Viena; Año: 2009 vol. 283 p. 133 - 147

0378-2697

The composition of the floral nectar sugars andamino acids of four species of Passiflora (P. foetida,P. caerulea, P. suberosa, and P. misera) included in differentinfrageneric taxa and with distinct pollinationmechanisms has been studied. The effect of weather andfloral age on nectar volume, existence, and total and relativeamounts of the various compounds was explored. Theproportion of sugars was rather constant within a givenspecies whereas the composition, number, and total quantityof amino acids showed great intraspecific and intraplantvariability; these nectar properties were independentof floral stage or meteorological conditions. Speciesbelonging to the same subgenus displayed equivalent sugarratios and similar total amount of amino acids, so thesecharacteristics might be conservative in the genus. For allspecies, the amino acid concentration surpassed knownvalues for their respective pollination syndromes, viz. beeand wasp-pollinated flowers. No relationship emergedbetween pollinators with different glossa length and nectarswith distinct sugar ratios. Rather, nectar chemical compositionseems to reflect taxonomic relationships.