Using isozymes markers, we test BORRALHO and POTTS' (1996) hypothesis that poorer growth of open-pollinated (OP) families of Eucalyptus globulus grown from seed collected from less dense stands is a consequence of lower outcrossing rates. A significant relationship between stand density class and outcrossing rate was found, with outcrossing rates near one for families from closed forests. In support of BORRALHO and POTTS' (1996) hypothesis, lower parental breeding values were generally associated with lower outcrossing rates. This is no doubt due to a higher proportion of less vigorous selfs within an OP family depressing mean growth relative to families where inbred progeny were virtually absent. It is suggested that the precision of predicting breeding values with OP progenies may be improved by adjusting family performance for individual outcrossing rate.
History
Publication title
Silvae Genetica
Volume
45
Article number
4
Number
4
ISSN
0037-5349
Publication status
Published
Rights statement
BM Potts. Free online access to the archives of SILVAE GENETICA