Extranuptial nectaries in Carapa Aubl. (Meliaceae-Cedreloideae)

[摘要] Ant-plantinteractionsmediatedbyspecialstructuresprovidedbyplantssuchasdomatia,extrafloralnectaries(EFNs)andfoodbodies,areveryfrequentintropicalecosystems.TounderstandwhyantsarefrequentlyencounteredonmostspeciesofCarapaAubl.(Meliaceae),weinvestigatedthepresenceofextranuptialnectaries(ENNs)inall27speciesofthegenus,spanningitsentiredistributionalrangeintropicalAfricaandAmerica.Wereportforthefirsttimeinthegenustheoccurrenceofextrafloralnectaries(atthebaseofthepetiole,alongtherachisofthepinnatelycompoundleaf,onbracts)petalinenectaries(ontheoutersurfaceofpetals),andpericarpialnectaries(onthesurfaceoffruits),andconfirmthepresenceofnectariesonleafletsinCarapa.Petiolarnectariesarethemostcommon,occurringin85%ofthespecies.Nectariesweremainlyactiveinyoungdevelopingplantorgans.Antswereobservedforagingonexudatesfromthesenectaries.ThesecretionsfromtheseglandshelptoexplaintheabundanceofantsonCarapatrees.AlthoughsimilarnectarieswerealsofoundinothermembersofthesubfamilyCedreloideae,theirpositionandfrequencyprovidenewcharactersfortheidentificationofCarapaspeciesinthefieldandtheherbarium.Asinothermyrmecophilousplants,ENNsprobablyconferadaptiveadvantagestoCarapatrees.

[学科分类] 植物学

[关键词] Carapa;extrafloral nectaries;Meliaceae;myrmecophily;pericarpial nectaries;petaline nectaries;Carapa;Meliaceae;myrmécophilie;nectaires extrafloraux;nectaires péricarpiaux;nectaires pétalaires