Abstract:
Warburgia ugandensis Sprague (Canellaceae) occurs in East and Central Africa, and the species is of
great medicinal importance to the local communities where it occurs. As the wild populations diminish,
planted stands will in future be used as the source of medicinal products as well as germplasm. This
study investigated the levels of out-crossing rates to provide knowledge for proper planning in future
cultivation programmes. The mating parameters estimated using the mixed mating model (software
MLTR) showed the species to be predominantly out-crossing (89%) with significant levels of selfing.
The multi-locus population out-crossing rate was higher than the single-locus population out-crossing
rate (tm- ts= 0.023; SE = 0.010), implying that there was less likelihood of mating between relatives (biparental
inbreeding). Low values were also obtained for the correlation of paternity, rp(s) = 0.028 (SE =
0.040) and correlation of selfing among family, rs = 0.016 (SE = 0.015). For most loci, allele frequencies
of pollen and ovule contributions to the progeny genotypes were significantly different (P <0.05). These
results indicate that with proper sampling, the populations being established for conservation, breeding
and planting purposes will be able to sustain high genetic diversity found in the wild populations.
