Juvenile–mature relationships for wood density in Pinustaeda

Abstract

Open-pollinated seeds were collected from loblolly pine (Pinustaeda L.) selections made in natural stands in eastern North Carolina, then planted in a short-term, closely spaced test and in a conventional genetic test. Wood density measurements from seedlings, from older trees, and from parents aged 40–75 years old were used to estimate the genetic covariance structure between juvenile and mature wood. These data were also used to determine if the genetic relationship between juvenile and mature wood varied with the estimation method used or with the fertilizer and irrigation treatments in the short-term test. Age–age relationships were moderately to highly positive and these results were corroborative using several methods: parent–offspring regression and coefficient of genetic prediction, half-sib analyses, and graphical use of type I selection mistakes. Strong age–age relationships (rg = 0.76 to 0.90) were expressed between juvenile wood in the short-term test and older-tree wood density in the genetic test. Moderate to high heritabilities (h2 = 0.55–0.76) were estimated for juvenile wood in short-term tests. The latter estimates tended to be higher than heritability estimates based on parent–offspring regression (h2 = 0.23–0.25). There was negligible family × treatment interaction due to rank change between short-term testing treatments. Height and specific gravity expressed a slight positive correlation at all ages.

Improving models of wood density by including genetic effects: A case study in Douglas-fir

“…There are fewer reports of age-age genetic correlations, but they seem to be higher than phenotypic correlations [13,42]. This observation supports the theory that major differences between the environments of young and adult trees are responsible for the low phenotypic correlations.…”

Genetic correlations between wood quality traits of Pinus pinaster Ait

“…The strong genetic relationship between density and each one of its components highlights the fact that overall density is a complex trait resulting from different combinations of the fraction, and relative density of each component (Hylen, 1997). All correlations with RD were positive, with the exception of EWW where strong negative genetic correlations were detected, due to the fact that, contrary to latewood, earlywood is characterized by lower density, larger lumens, and thinner cell walls (Hylen, 1999;Kumar, 2002;Loo et al, 1984;Talbert et al, 1983;VargasHernandez and Adams, 1992;Williams and Megraw, 1994;Zobel and van Buijtenen, 1989). These results are consistent with those obtained in studies on Pseudotsuga menziesii (Hodge and Purnell, 1993) and Picea mariana (Abdel-Gadir et al, 1993).…”

Genetic correlations between wood density components in Pinus pinaster Ait

“…Effectively, even though some works have shown a negative genetic and/or phenotypic correlation for Pseudotsuga menziesii [44,49,69] and Tsuga heterophylla [24], others have shown a very low or an inexistent genetic and/or phenotypic correlation for Pseudotsuga menziesii [4], Picea mariana [74,76,77], Picea abies [23], Abies grandis [14], Pinus radiata [21,57], Pinus taeda [10,50] and for several conifers [73], while [71] mentions a moderately positive genetic correlation for Pinus taeda, [40] for several conifers, and [13] a high and positive phenotypic correlation for Pinus peuce.…”