Genetic variation in growth, wood density and bark thickness of Eucalyptus dunnii.

Two Eucalyptus dunnii provenance-family trials that included 53 families representing 6 provenances at Guilin and Liuzhou in Guangxi,were used to study the genetic variation and genotype by environment interaction for diameter at breast height(DBH) at 8.5-years,and DBH,height,stem volume,wood density and bark thickness at 10.5-years.The 10.5 year results showed: the mean volumes of individual trees at Guilin and Liuzhou were 0.218 and 0.189 m3,the average wood basic densities were 521.0 and 483.7 kg·m-3 respectively;and,the average bark thicknesses at breast height were 1.15 and 1.26 cm respectively.For the 10.5-years' growth traits and wood density,there were no significant differences among provenances(P0.10),but significant differences among families(within provenances) for 10.5-years wood density(P0.05).However,there were no significant differences(P0.10) at any level for bark thickness at breast height,including no significant genotype by environment interactions for this trait.There were no significant interaction between sites and provenances(P0.10) for all the traits except 8.5-years DBH,but significant interactions between sites and families(within provenance)(P0.05)were found for all the traits studied except 10.5-years DBH.The heritabilities of DBH at 8.5-years and 10.5-years DBH and height were between 0.128 9-0.234 5,the heritability of wood basic density were 0.700 0-0.962 9,bark thickness were 0.105 3-0.335 7.