Eucalyptus globulus Labill. is increasingly considered for supply of solid-wood products such as sawlogs, yet genetic studies of solid-wood traits have been lacking. We estimated genetic parameters of growth and form traits that affect log value in full-sib families from two advanced-generation breeding populations on eight sites in Western Australia. Mean single-site heritability was 0.11 ± 0.01 for diameter at breast height (DBH), 0.28 ± 0.05 for stem straightness, 0.09 ± 0.02 for branch thickness, and 0.05 ± 0.02 for forking incidence. Dominance effects were significant (p < 0.05) at four sites for DBH and branch thickness and at three sites (one population) for straightness. Mean intersite additive genetic correlations were 0.76 ± 0.06 for DBH (n = 7), 0.75 ± 0.11 for stem straightness (n = 7), and 0.58 ± 0.07 for branch thickness (n = 4). Mean intersite dominance genetic correlations were 0.90 ± 0.04 for DBH (n = 7), 0.26 ± 0.27 (n = 4) for straightness, and 0.68 ± 0.11 for branch thickness (n = 3). Additive genetic correlations between DBH and straightness ranged from –0.71 ± 0.23 to 0.33 ± 0.19 with an average of –0.18 ± 0.12 (n = 8). Genetic correlations between DBH and branch thickness were mostly weak although straightness was generally associated with thinner branches (mean additive correlation 0.44 ± 0.15, n = 6). We conclude that prospects appear favourable for improving the solid-wood value of E. globulus by selection and breeding.

Peridermium pini aeciospores from lesions on Scots pine (Pinus sylvestris) in Scotland and in Thetford Eorest, East Angha, differed in terms of germ tube morphology and cytology. The former produced long aseptate germ tubes containing a pair of nuclei. The latter produced short septate germ tubes, each cell containing a single nucleus. One third of the 'Scottish' germ tubes ended in a vesicle. Nuclei could be counted in only a small proportion of ungerminated aeciospores. On average 83% of Scottish spores had two nuclei and 4% had one. The equivalent figures for Thetford spores were 66 and 20%. A small number of aeciospore samples from other parts of England resembled Scottish spores rather than Thetford spores in germ tube morphology and cytology.Both Scottish and Thetford spores proved capable of causing infection of wounded Scots pine shoots. In addition, some Thetford spores caused infection on leaf discs taken from certain Paeonia cultivars. Erom these results it is concluded that two distinct forms of Peridermium pini exist in the UK. The implications of this finding are discussed in relation to the history of pine stem rust in the country and the genetics and taxonomy of P. pini.

A method for the production of multiple clonal plantlets of Pinuscaribaea var. hondurensis Morlet, P. oocarpa Schiede, and P. tecunumanii Equiluz and Perry (P. patula Schiede and Deppe ssp. tecunumanii (Equiluz and Perry) Styles) from juvenile sources is described. The procedure is based on the spontaneous production of axillary shoots following shoot elongation. Much interclonal variation exists with respect to expiant multiplication. The addition of activated charcoal (0.1%) stimulates shoot elongation, especially in recalcitrant clones of P. caribaea. Axillary bud initiation may be stimulated by 6-benzylaminopurine, but levels above 1 μM can result in failure of induced buds to form shoots. Rooting occurs at about 50% in nonsterile peat–perlite medium without auxin pretreatment. Rooted plantlets can be readily hardened and will grow normally in the glasshouse.

Realised gains in stand volume of Eucalyptus globulus Labill. families at 7-9 years were compared with gains predicted at 3.5 years. Gain predictions were based on height, diameter at breast height (DBH), sectional area, and stem volume for 153 full-sib families and 18 commercial checks in five-tree line plots on three West Australian sites. Singlesite narrow-sense heritability estimates were 0.12-0.24 for height, 0.08-0.12 for DBH, 0.09-0.13 for sectional area and 0.14-0.19 for stem volume. Genetic dominance effects were significant (p<0.05) in most cases and the estimated dominance:additive genetic variance ratio was heterogeneous for height and DBH.Stand volume was measured for 93 of the same families and checks in 40-tree block plots on four sites. Heritability of stand volume was 0.25-0.76, with an across-sites estimate of 0.41. Dominance effects were statistically absent at two sites. Estimated region-wide additive genetic correlations between selection traits (in line plots) and stand volume (in block plots) ranged from 0.86 to 0.90. Estimated stand volume gain was 23% of the mean for the best 12% of families and 14% of the mean for the best 24% of families.Realised gain was under-estimated by predictions based on height, DBH, and sectional area, which had smaller coefficients of additive variation than did stem volume. It is concluded that although BLUP analysis of early-age height and DBH can provide for 2 indirect selection on E. globulus stand volume, analysis of stem volume is required to predict genetic gain at an appropriate scale.

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