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Long‐pollen Movement and Deviation of Random Mating in a Low‐density Continuous Population of a Tropical Tree Hymenaea courbaril in the Brazilian Amazon
Author(s) -
Eduardo André,
De Lacerda Biscaia,
Kanashiro Milton,
Sebbenn Alexandre Magno
Publication year - 2008
Publication title -
biotropica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.813
H-Index - 96
eISSN - 1744-7429
pISSN - 0006-3606
DOI - 10.1111/j.1744-7429.2008.00402.x
Subject(s) - biology , pollen , inbreeding , outcrossing , mating , fixation index , population , pollination , botany , mating system , gene flow , biological dispersal , zoology , genetic variation , genetic structure , demography , genetics , sociology , gene
Mating system and pollen flow are two key elements to understand the genetic structure of tree species. Mating and pollen‐dispersal patterns of a low‐density population of bat pollinated Hymanea courbaril were examined before logging in a 546‐ha plot in the Brazilian Amazon. The multilocus genotypes of nine microsatellite loci were determined for 130 adult‐trees and 367 seeds collected from 20 seed‐trees. Mating system analysis, using mixed‐mating model and paternity analysis showed that the studied population is perfectly outcrossed ( t m = 1.002), and probably self‐incompatible. However, significant deviations from random mating were detected for mating among relatives ( t m − t s = 0.096, P < 0.05) and correlated matings ( r p = 0.289, P < 0.05), indicating inbreeding in the population and that part of offspring are full‐sibs (28.9%). Inbreeding was reflected in the positive and significant fixation index observed in adult trees ( F = 0.137, P < 0.05), although no significant inbreeding was detected in offspring ( F = 0.074, P > 0.05). The effective number of pollen donors mating with each seed‐tree was determined to be low ( N ep ≈ 4). The average of pollen flow distance was measured inside of the plot by both paternity (827 ± 429 m) and TwoGener analysis (115–363 m). However, this underestimated pollen dispersal distance, since the detected rate of pollen immigration inside of the plot was high (55%). The observed long‐pollen dispersal distance is probably related to pollination by bats and the low density of reproductive trees in the site.