02250naa a2200253 a 450000100080000000500110000800800410001910000170006024501230007726000090020052015310020965000130174065000130175365000140176665300110178065300330179165300170182465300100184165300240185170000180187570000190189370000170191277300670192914069302016-11-29       2003    bl uuuu     u00u1 u    #d1 aALVES, R. M.  aMating system in a natural population of Theobroma grandiflorum (Willd. ex Spreng.) Schum., by microsatellite markers.  c2003  aThe aim of this research was to study the mating system of a natural population of Theobroma grandiflorum (cupuassu) from Nova Ipixuna, Pará state, using microsatellite markers. Eight polymorphic microsatellite loci were analyzed in eight families, each represented by 10 six-month old seedlings derived from open-pollinated pods. The estimation for the multilocus outcrossing rate ($tm= 1.0) and individual outcrossing rate ($t= 1.0) for this population suggests that T. grandiflorum may be a perfect outbreeding (allogamous) species. Likewise, for the studied population the estimate for single locus outcrossing rate ($ts) was elevated (0.946), but lower than $tm, confirming the likely outcrossing character of the species and suggesting the occurrence of 5.4% biparental inbreeding rate ($tm-$ts). The estimation of genetic divergence ($FST) between allelic frequencies in ovules and pollen revealed a deviation from random mating in 75% of the evaluated loci. Likewise, the estimate of correlation of paternity ($rp= 0.930) and the mean coefficient of co-ancestrality within families ($?xy= 0.501) indicated that the outcrossings were predominantly correlated, and the offspring were full-sibs. These results suggested that for this particular population of T. grandiflorum, the sampling strategy for genetic conservation and breeding should adopt specific models for families derived from correlated outcrossing (full-sibs) and not the ones usually adopted in classic outcrossing species breeding programs (half-sibs).  aAmazonia  aCupuaçu  aGenética  aBrasil  aConservação de germoplasma  aNova Ipixuna  aPará  aPopulação natural1 aARTERO, A. S.1 aSEBBENN, A. M.1 aFIGUEIRA, A.  tGenetics and Molecular Biologygv. 26, n. 3, p. 373-379, 2003.