Genetic parameters for spiral-grain angle in two 19-year-old clonal Norway spruce trials

Abstract

-Spiral grain was measured for all annual rings on wood discs taken at a single sampling height from two 19-year-old (field age) Norway spruce (Picea abies (L.) Karst.) clonal trials. In both trials, the mean grain angle reached a maximum inclination to the left at ring number 4, followed by a monotonic decrease towards a right-handed inclination. Clonal means of mean grain angle of rings 3 to 15 ranged from 0.5 to 4.7 degrees and from -0.2 to 5.3 degrees in the two trials, respectively. The broad-sense heritability of mean grain angle was 0.42 in both trials and the slope of the radial grain-angle development showed heritabilities varying between 0.26 and 0.40. Estimates of genotypic correlations indicated that clones with a high grain angle in the inner rings tended to have a more rapid development towards a straight angle in the following rings. Selection based on any of the rings in the interval from ring numbers 5 to 10 was most efficient in decreasing the average grain spirality at the sampling level considered. spiral grain / heritability / genotypic correlation / correlated response Résumé -Paramètres génétiques de l'angle du fil du bois dans 2 tests clonaux d'Épicéa commun âgés de 19 ans. L'angle du fil du bois a été mesuré pour tous les cernes à partir de disques prélevés à la même hauteur dans 2 tests clonaux d'Épicéa commun (Picea abies (L.) Karst.) âgés de 19 ans. Dans les 2 dispositifs, l'angle moyen atteint une inclinaison maximale à gauche au cerne 4. Elle est suivie d'une diminution monotonique de l'angle vers une inclinaison à droite. Les moyennes clonales de l'angle moyen des cernes 3 à 15 s'étalent de 0,5 à 4,7 degrés et de -0,2 à 5,3 degrés respectivement dans les deux tests. L'héritabilité au sens large de l'angle du fil est de 0,42 dans les 2 essais et la pente de la régression de l'angle sur les cernes annuels présente une héritabilité variant entre 0,26 et 0,40. Les corrélations génotypiques montrent que les clones avec un angle élevé dans les cernes proches de la moëlle ont tendance à présenter une évolution plus rapide de l'angle vers un angle droit dans les cernes suivants. Une sélection basée sur un des cernes compris entre le 5 e et le 10 e est apparue plus efficace pour diminuer l'angle moyen du fil au niveau de l'échantillon considéré.angle du fil / héritabilité / corrélation génotypique / gain génétique

Genetic parameters for wood quality traits and resistance to the pathogens Heterobasidion parviporum and Endoconidiophora polonica in a Norway spruce breeding population

“…SG is the tracheids deviation from the vertical axis in degrees. It was measured using an instrument developed at Chalmers institute, Sweden, and the method is described and evaluated by Hannrup et al (2003). Positive values indicate left oriented grain angle.…”

Genetic parameters for grain angle in 28-year-old Norway spruce progeny trials and their parent seed orchard

“…In Norway spruce genotype-environment (G×E) interaction for grain angle has not been significant [2,11]. Correlations between grain angle and growth and other wood properties have generally also been weak or not significant [3,9,11]. The high heritability and genetic variation suggests that the shape stability of Norway spruce sawn wood might be improved by selection and breeding for low grain angle.…”

“…High heritability and substantial genetic variation have been observed for grain angle in several conifer species, e.g. Norway spruce [2,10], Scots pine (Pinus sylvestris L.) [11], Sitka spruce (Picea sitchensis (Bong.) Carr) [12] and radiata pine (Pinus radiata D. Don) [4,24].…”

“…Carr) [12] and radiata pine (Pinus radiata D. Don) [4,24]. In Norway spruce genotype-environment (G×E) interaction for grain angle has not been significant [2,11]. Correlations between grain angle and growth and other wood properties have generally also been weak or not significant [3,9,11].…”

“…Faster, non-destructive methods used on standing trees only produce observations from the peripheral annual rings close to the bark, making the cambial age at the time of assessment a very important factor to consider [13,24]. Nonetheless, most research on genetic grain angle variation in Norway spruce, destructive as well as non-destructive, have hitherto focused on young material and consequently on juvenile wood grain angles [2,10,11].…”