Early-age genetic parameter estimates for diameter, height and volume in Pinus echinata mill. and implications for breeding
Smith, Stacey L.
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A first-generation shortleaf pine progeny test was established in 2002 at George O. White State Forest Nursery at Licking, Missouri as part of the Mark Twain National Forest breeding program in a randomized complete block design with 6 blocks and 305 full-sib families. The full-sib families were developed using eight 6-parent disconnected half-diallels plus a single-pair mating design. Variance component predictions were made for height, diameter and volume at age 4 and 6. The influence of additive variance on diameter and height increase from age 4 to 6 and decreased for volume. Estimates of narrow-sense heritability were low for all traits at both ages. A comparison of parental GCAs and family SCAs revealed the genetic model for this population was broadly additive, indicating that tree improvement strategies will will likely achieve greatest gains through selection on GCA in volume and may be able to utilize SCA.