Genetic Control of Rooting Ability of Stem Cuttings in Eucalyptus nitens

Abstract

Genetic parameters for rooting of stem cuttings inEucalyptus nitens (Deane & Maiden) Maiden wereestimated from almost 600 control-pollinated seedlings grown in pots in anenvironmentally controlled glasshouse. Multiple harvests spanning a 9 monthperiod were taken from the 67 families arising from a partial diallel matingdesign among 25 unrelated parents. Overall, of the 14205 cuttings that wereset, only 14% initiated roots. There was little if any biologicallyimportant harvest-by-family interaction for rooting. Individual tree narrowsense heritability (h²) was highat 0.4–0.5. The ratio of specific combining ability variance to generalcombining ability variance was low. The operational implications forincorporating this trait into a breeding program are discussed.