Cm. Hardner et al., STAND DENSITY INFLUENCES OUTCROSSING RATE AND GROWTH OF OPEN-POLLINATED FAMILIES OF EUCALYPTUS-GLOBULUS, Silvae Genetica, 45(4), 1996, pp. 226-228
Using isozymes markers, we test BORRALHO and POTTS' (1996) hypothesis
that poorer growth of open-pollinated (OF) families of Eucalyptus glob
ulus 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 n
ear one for families from closed forests. In support of BORRALHO and P
OTTS' (1996) hypothesis, lower parental breeding values were generally
associated with lower outcrossing rates. This is no doubt due to a hi
gher proportion of less vigorous selfs within an OP family depressing
mean growth relative to families where inbred progeny were virtually a
bsent. It is suggested that the precision of predicting breeding value
s with OP progenies may be improved by adjusting family performance fo
r individual outcrossing rate.