Juvenile–mature relationships and heritability estimates of several traits in loblolly pine (Pinustaeda)

1984 ◽  
Vol 14 (6) ◽  
pp. 822-825 ◽  
Author(s):  
Judy A. Loo ◽  
C. G. Tauer ◽  
J. P. van Buijtenen

Heritability estimates for wood specific gravity of loblolly pine (Pinustaeda L.) in east Texas were high and relatively constant for all ages of wood sampled, but tracheid length was found to have low heritability at all ages. Heritability estimates for tracheid length declined with age after age 4 years. Coefficients of genetic prediction indicated that specific gravity of age 2 wood is a reliable predictor of wood specific gravity at age 25. Genetic covariances between juvenile and mature tracheid length were approximately zero. Coefficients of genetic prediction and genetic correlations between specific gravity and height and diameter at age 20 years indicated a strong negative relationship.

1982 ◽  
Vol 6 (3) ◽  
pp. 177-180
Author(s):  
J. B. Jett ◽  
J. T. Talbert

Abstract Data from thinnings of 11 genetic tests with an average age of 10 years and from 364 eight-year-old second-generation selections were analyzed to provide an estimate of gain from one cycle of selection for wood specific gravity. Utilizing mid-parent, mature, wood specific gravities and progeny juvenile wood specific gravities, coefficients of genetic prediction, CGP = 0.55 and 0.41, were calculated for the genetic test thinning sample and second-generation selection sample. Expressed as a percentage of the mean, gain from selection was calculated to be 2.6 percent. A strategy was also developed to include wood specific gravity in the North Carolina State Cooperative's second-generation loblolly pine (Pinus taeda L.) improvement program. High heritability figures indicate little need to develop extensive family information for wood specific gravity in advanced-generation breeding programs.


1978 ◽  
Vol 2 (4) ◽  
pp. 118-120 ◽  
Author(s):  
Julian R. Beckwith ◽  
Mervin Reines

Abstract Two loblolly pine plantations were examined after one was fertilized by airplane, and wood properties of dominant and co-dominant trees in each were compared. Although there was a relative reduction in wood specific gravity after fertilization, the data suggest that treated trees produced a greater weight of wood per tree than did the controls.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (4) ◽  
pp. 31-36 ◽  
Author(s):  
DAVID E. WHITE ◽  
CHARLES COURCHENE ◽  
THOMAS MCDONOUGH ◽  
LAURIE SCHIMLECK ◽  
DAVID JONES ◽  
...  

We quantified the effects of wood density (chip specific gravity) and wood chemical composition (cellulose, hemicellulose, and lignin) on the kraft pulp yield of 13-year-old loblolly pine trees (Pinus taeda) grown as part of a genetic selection study. Both bleachable (kappa No. 30) and linerboard grade (kappa No. 100) pulps were made from 18 trees selected for combinations of wood specific gravity and cellulose:hemicellulose:lignin ratios. Statistical analysis indicated that digester pulp yield correlated significantly with wood xylan content and cellulose-to-lignin ratio but was not strongly correlated to wood specific gravity. Near infrared (NIR) spectra were collected from wood samples and correlated with the total kraft pulp yields. The analyses for both kappa No. 30 and kappa No. 100 pulps provided strong calibration statistics, suggesting that papermakers can use NIR spectroscopy to esti-mate the bleachable and linerboard grade pulp yields of P. taeda whole-tree samples.


1989 ◽  
Vol 19 (10) ◽  
pp. 1347-1350 ◽  
Author(s):  
L. J. Frampton Jr. ◽  
J. B. Jett

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.


2004 ◽  
Vol 28 (4) ◽  
pp. 196-204 ◽  
Author(s):  
Jennifer H. Myszewski ◽  
Floyd E. Bridgwater ◽  
William J. Lowe ◽  
Thomas D. Byram ◽  
Robert A. Megraw

Abstract In recent years, several studies have examined the effect of microfibril angle (MFA) on wood quality. However, little research has been conducted upon the genetic mechanisms controlling MFA. In this study, we examined the heritability of MFA in loblolly pine, Pinus taeda L.,and its genetic relationships with height, diameter, volume, and specific gravity. Increment cores were collected at breast height from 20 to 25 progeny from each of 12 to 17 crosses (among 11 parents) in two modified partial-diallels in different locations in southern Arkansas. Specific gravitywas measured on segments containing rings 1 through 5 and on segments containing rings 6 through 20. MFA was measured on the earlywood and latewood sections of rings 4, 5, 19, and 20. Rings 4 and 5 were chosen as representative of core wood and rings 19 and 20 as representative of outer wood. Analyses of variance revealed statistically significant genetic and environmental influences on MFA. Significant general combining ability (GCA), specific combining ability (SCA), and SCA × block effects indicated that there are both additive and nonadditive genetic influences on MFA. Individual-tree, narrow-sense heritability estimates were variable, ranging from 0.17 for earlywood (ring) 4 MFA to 0.51 for earlywood (ring) 20 MFA. Genetic correlations between MFA, specific gravity, and the growth traits were nonsignificant due to large estimated standard errors. South.J. Appl. For. 28(4):196–204.


1991 ◽  
Vol 21 (7) ◽  
pp. 1080-1085 ◽  
Author(s):  
J. B. Jett ◽  
S. E. McKeand ◽  
R. J. Weir

The stability of wood specific gravity for 12-year-old loblolly pine (Pinustaeda L.) was evaluated for 18 open-pollinated families and four bulked seed lots representing provenances from the eastern shore of Maryland; Marion County, Florida; Gulf Hammock, Florida; and Livingston Parish, Louisiana. Wood samples were collected from seven plantings chosen to provide a north–south and east–west sample distribution essentially encompassing an area spanning the natural range of loblolly pine. There was significant genotype × environment interaction, and 4 of the 18 families were classified as unstable for specific gravity. These four families accounted for 49.5% of the genotype × environment interaction sum of squares. However, the loss in potential gain in a breeding program for specific gravity due to the presence of a significant genotype × environment interaction was estimated to be only 1%. Loblolly pine from the Florida provenances and from the widely planted Livingston Parish provenance consistently displayed low specific gravity and ranked at or near the bottom at all test locations, including the southernmost plantings.


2002 ◽  
Vol 32 (6) ◽  
pp. 1025-1038 ◽  
Author(s):  
Ryan A Atwood ◽  
Timothy L White ◽  
Dudley A Huber

One hundred and thirteen open-pollinated families from Florida source loblolly pine (Pinus taeda L.) were tested in four states in the southeastern United States. Heritabilities and genetic correlations were estimated for volume, specific gravity, and latewood percentage at three different growth stages: juvenile (ages 0–10 years), mature (11–17 years), and total (0–17 years). Heritabilities of growth traits (0.09–0.11) were consistently lower than for wood property traits (0.16–0.33). Growth traits for Florida loblolly exhibited high genotype × environment interaction (rB = 0.44), whereas wood properties did not (rB = 0.90). The higher heritabilities and genetic stability across environments make wood properties amenable to genetic manipulation through breeding programs. In contrast, the high genotype × environment interaction of growth traits for Florida loblolly pine requires more research to understand the possible implication of these effects on breeding programs. Trait–trait and age–age genetic correlations were determined for growth and wood properties. Strong positive age–age correlations were present for latewood percentage, volume, and specific gravity. Weak negative trait–trait genetic correlations existed between specific gravity and volume across ages (–0.13 to –0.43). No genetic correlation existed between latewood percentage and volume, while a moderate favorable genetic correlation existed between latewood percentage and specific gravity (0.47 to 0.59). Genetic gains in volume and specific gravity were compared for various types of selection. In one type, forward selection of the top 20 individuals (of 3484) based on 17-year volume, resulted in a 20.5% genetic gain in volume; however, a concomitant loss of –6.4% also occurred in specific gravity. If a selection index was used to hold specific gravity constant, a gain in total volume of 14% was obtained.


2019 ◽  
Vol 65 (4) ◽  
pp. 469-482 ◽  
Author(s):  
Trevor D Walker ◽  
Fikret Isik ◽  
Steven E McKeand

AbstractAcoustic time of flight and drill resistance (surrogates for wood stiffness and density, respectively) were measured on 11,097 standing trees from 269 pollen-mix families of loblolly pine (Pinus taeda L.) in 6- to 9-year-old progeny tests at eight sites across the southeastern United States. Specific gravity was measured on two test sites. The phenotypic correlation between specific gravity and drill resistance was moderate (r = 0.68), whereas the genetic correlation was very strong (rg = 0.96). Narrow-sense heritabilities for acoustic time of flight and drill resistance were around 0.35 for individual trees and very strong (0.90) for family means. High genetic correlations (>0.80) between pairs of sites suggested a low genotype-by-environment interaction for both traits. Genetic correlations between wood quality traits and other economic traits (growth and stem straightness) were low except for a moderate correlation between acoustic time of flight and tree slenderness (rg = –0.64). The checklot ranked near the middle for both wood quality traits, implying no inadvertent selection occurred in this population that has been selected intensively for volume productivity. This study is the first to apply these tools in a large breeding program, and results suggest they are effective for selecting genotypes for wood quality.


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