Analysis of the mating system of Racosperma auriculiforme (formerly Ac
acia auriculiformis) in a seed production area in Zaire was conducted
using a mixed mating model at five polymorphic loci (Est-2, Est-3, G6p
-dh, Nadhdh-2, Pgm-1). Single-locus estimates of outcrossing rate vari
ed widely between 0.615 and 1,204 and were significantly heterogenous
among and within the stands. Weighted means of single-locus estimates
of outcrossing rates (t(s)) ranged from 0.859 to 1.032 while multilocu
s estimates of outcrossing rates (t(m)) ranged from 0.863 to 1.059. Co
mparisons between the single-locus estimates and the multilocus estima
tes of outcrossing rates indicated that most of the inbreeding detecte
d was due to consanguineous (sibling) matings rather than selfing. Com
parisons of observed and expected inbreeding coefficients indicated a
general deficit of heterozygotes over the frequencies expected from ra
ndom mating in the single stands and the pooled stands. Locus to locus
variation in outcrossing rates suggested that violation of the mixed
mating model might have occurred. Implications for seed production, co
llection, and distribution for reforestation are discussed.