Functional decoupling between flowers and leaves in the Ameroglossum pernambucense complex can facilitate local adaptation across a pollinator and climatic heterogeneous landscape.

MACHADO IC; GALETTO L; WANDERLEY AM

JOURNAL OF EVOLUTIONARY BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 29 p. 528 - 540

1010-061X

Decoupling between floral and leaf traits is expected in plants with specializedpollination systems to assure a precise flower?pollinator fit, irrespectiveof leaf variation associated with environmental heterogeneity (functionalmodularity). Nonetheless, developmental interactions among floral traitsalso decouple flowers from leaves regardless of selection pressures (developmentalmodularity). We tested functional modularity in the hummingbirdpollinatedflowers of the Ameroglossum pernambucense complex whilecontrolling for developmental modularity. Using two functional traitsresponsible for flower?pollinator fit [floral tube length (TL) and anther?nectarydistance (AN)], one floral trait not linked to pollination [sepal length(SL), control for developmental modularity] and one leaf trait [leaf length(LL)], we found evidence of flower functional modularity. Covariationbetween TL and AN was ca. two-fold higher than the covariation of eitherof these traits with sepal and leaf lengths, and variations in TL and AN,important for a precise flower?pollinator fit, were smaller than SL and LLvariations. Furthermore, we show that previously reported among-populationvariation of flowers associated with local pollinator phenotypes wasindependent from SL and LL variations. These results suggest that TL andAN are functionally linked to fit pollinators and sufficiently decoupled fromdevelopmentally related floral traits (SL) and vegetative traits (LL). Theseresults support previous evidences of population differentiation due to localadaptation in the A. pernambucense complex and shed light on the role offlower?leaf decoupling for local adaptation in species distributed across bioticand abiotic heterogeneous landscapes.