Floral scent compounds of Amazonian Annonaceae species pollinated by smallbeetles and thrips

Chemical analysis (GC-MS) yielded a total of 58 volatile compounds in the f loral scents of six species of Annonaceae distributed in four genera (Xylop ia, Anaxagorea, Duguetia, and Rollinia). Xylopia aromatica is pollinated pr incipally by Thysanoptera and secondarily by small beetles (Nitidulidae and Staphylinidae), whereas the five other species were pollinated by Nitiduli dae and Staphylinidae only. Although the six Annonaceae species attract a s imilar array of pollinator groups, the major constituents of their floral s cents are of different biochemical origin. The fragrances of flowers of Ana xagorea brevipes and Anaxagorea dolichocarpa were dominated by esters of al iphatic acids (ethyl 2-methylbutanoate, ethyl 3-methylbutanoate), which wer e not detected in the other species. Monoterpenes (limonene, p-cymene, alph a -pinene) were the main scent compounds of Duguetia asterotricha, and naph thalene prevailed in the scent of Rollinia insignis flowers. The odors of X . aromatica and Xylopia benthamii flowers were dominated by high amounts of benzenoids (methylbenzoate, 2-phenylethyl alcohol). (C) 2000 Elsevier Scie nce Ltd. All rights reserved.