Juvenile wood specific gravity of loblolly pine tissue culture plantlets and seedlings

Abstract

Juvenile-wood specific gravity of loblolly pine (Pinustaeda L.) tissue culture plantlets and seedlings were compared. Wood samples collected from several (6 to 13) families at three sites, each at a different age (2, 3, and 6 years), showed a significant difference between the overall plantlet and seedling mean specific gravity only in the youngest material (0.387 versus 0.356, respectively). Another collection of wood samples from three different sites at age 5 years showed that the within-site variation in specific gravity for a single clone was 29% that of the open-pollinated family from which it was derived. When tissue culture techniques become practical, operational clonal plantations of loblolly pine should offer substantial improvement in the uniformity of wood produced relative to the heterogeneous seedling-origin plantations currently being established.