Abstract

Estimates of outcrossing rate were determined for four populations of Eucalyptus marginata from the jarrah forest in south-west Western Australia. The mean multilocus outcrossing rate (t = 0.81) was high in all populations and was towards the high end of the range of outcrossing rates that have been observed in other mass-flowering eucalypt species. A significant proportion of the inbreeding detected appeared to be due to biparental inbreeding, and the levels of correlated paternity were unexpectedly high. Differences between populations were generally not significant, although trees from a disturbed site affected by disease showed lower outcrossing, higher biparental inbreeding and higher correlated paternity, suggesting an increase in population structure compared with trees from disease-free sites.