Genetic analysis of fiber dimensions and their correlation with stem diameter and solid-wood properties in Norway spruce

Abstract

Adverse genetic correlations between growth traits and solid-wood, as well as fiber traits are a concern in conifer breeding programs. To evaluate the impact of selection for growth and solid-wood properties on fiber dimensions, we investigated the inheritance and efficiency of early selection for different wood-fiber traits and their correlations with stem diameter, wood density, modulus of elasticity (MOE), and microfibril angle (MFA) in Norway spruce (Picea abies L). The study was based on two large open-pollinated progeny trials established in southern Sweden in 1990 with material from 524 families comprising 5618 trees. Two increment cores were sampled from each tree. Radial variations from pith to bark were determined for rings 3-15 with SilviScan for fiber widths in the radial (RFW) and tangential (TFW) direction, fiber wall thickness (FWT), and fiber coarseness (FC). Fiber length (FL) was determined for rings 8-11. Heritabilities based on rings 8-11 using joint-site data were moderate to high (0.24-0.51) for all fiber-dimension traits. Heritabilities based on stem cross-sectional averages varied from 0.34 to 0.48 and reached a plateau at rings 6-9. The Bage-age^genetic correlations for RFW, TFW, FWT, and FC cross-sectional averages at a particular age with crosssectional averages at ring 15 reached 0.9 at rings 4-7. Our results indicated a moderate to high positive genetic correlation for density and MOE with FC and FWT, moderate and negative with RFW, and low with TFW and FL. Comparison of several selection scenarios indicated that the highest profitability is reached when diameter and MOE are considered jointly, in which case, the effect on any fiber dimension is negligible. Early selection was highly efficient from ring 5 for RFW and from rings 8-10 for TFW, FWT, and FC.

Non-Destructive Assessment of Wood Stiffness in Scots Pine (Pinus sylvestris L.) and its Use in Forest Tree Improvement

“…Moreover, prioritizing growth traits increases MFA, which negatively influences the quality of end-products, e.g., stiffness of sawn boards [56] or pulp yield [57]. A similar pattern of the expected genetic response after single-trait selection was also observed in lodgepole pine [6] or Norway spruce [12,58].…”

Models for Predicting Specific Gravity and Ring Width for Loblolly Pine from Intensively Managed Plantations, and Implications for Wood Utilization

“…Increasingly, loblolly pine plantations have been intensively managed to accelerate growth through improved genetics, intensive site preparations, weed control, decreased planting densities, and the use of multiple fertilizer applications [6,7]. As a result, site indices as high as 32 m (base age 25) have been achieved [8]. Through these treatments, the time required to grow loblolly pine sawtimber (≥30 cm diameter at breast height (DBH)) has decreased from 35-40 to 20-25 years, and as few as 16 years to reach a merchantable size for "chip-n-saw" (DBH between 20 cm and 30 cm) [9].…”

“…• X-ray densitometry to measure specific gravity [18][19][20] • X-ray diffraction to measure the microfibril angle [21][22][23] • Automated image analysis to measure fiber dimensions on macerated fibers [24,25] or on solid wood samples [26][27][28] • Near-infrared spectroscopy to predict a variety of properties [29][30][31] • Acoustics in combination with density to measure stiffness [32,33], or to correlate acoustic velocity values to MFA or tracheid length [34,35] • Light transmission to measure spiral grain [36,37] Of the aforementioned tools, X-ray densitometry has arguably been the most widely used to investigate radial patterns of variation. This is undoubtedly due to the overall importance of wood density, the ease of measurement, and the variety of X-ray densitometry instruments/techniques that are available [20].…”

Genetic analysis using parent-progeny relationship for wood quality traits in Norway spruce (Picea abies (L.) Karst.)

“…These operations may affect growth greatly but may have less impact on the genetic property of wood quality traits. This is because wood quality traits have higher heritability and little G by E [Chen et al, 2016, Hayatgheibi et al, 2017, Hong et al, 2014, Lenz et al, 2010, Wu et al, 2008]. Therefore, the parent-offspring relationship may still be used to estimate heritability for wood quality traits.…”