Gains from breeding radiata pine in Victoria. 1. Re-evaluation of clones for an improved seed orchard.  L. A. Pederick.  April 1981.  21 pp. (unpubl.)

SUMMARY

Recent results from 28 open-pollinated Pinus radiata D. Don (radiata pine) progeny trials were examined to identify the clones that had yielded the best progeny, i.e. those with the best breeding value. These trials had been established during the period 1962 to 1975, in various parts of Victoria.

The characteristics considered were growth rate (height, diameter, volume), straightness, branch thickness, frequency of ramicorns and forks, and wood density.

From 127 clones tested, 13 were found to yield vigorous progeny consistently over all sites on which they were tested (i.e. they were stable), to have generally good values for form characteristics and to have wood of average to high density. A further 13 clones yielded generally good progeny, though not of the same standard as those mentioned above; these clones were usually below the desired standard in one characteristic, which in some cases included below-average vigour at some trial sites.

These 26 clones have been recommended for use in a new seed orchard. This selection of clones differs substantially from that used in the existing orchards; it included only 4 out of the 16 clones used in the original orchard at Korweinguboora, and 13 of the 50 clones used in the orchards planted between 1966 and 1973.

It has been estimated that the improvement in growth rate from a new seed orchard established with this new group of clones, selected on the basis of genetic information, could be 8.7% above that of the existing orchards (and these have yielded about 7.4% more than the unimproved routine seed collections tested). Small improvements in other characteristics can also be expected.