[EN] Damage by the pine weevil Hylobius abietis L. (Coleoptera: Curculionidae) on Pinus pinaster Ait. was evaluated in a fertilization × progeny test in Galicia (NW Spain) to determine the genetic variation among families and the possibility to include the resistance to this insect as a selection criteria in the Galician maritime pine breeding program. Several damage and symptoms traits were evaluated. All these traits showed highly significant family effects and were strongly correlated among each other. Individual and family heritability estimates of the wound evaluations in the seedling stems were around 0.2 and 0.8, respectively. Strong genetic correlations among wounds and the average seedling color indicated that this last simple and subjective trait can be used for screening for pine weevil susceptibility. A positive genetic correlation was also observed between diameter growth and pine weevil damage. Faster growing families were more attacked hindering the possibility to include the susceptibility to the insect in the breeding program.[FR] Les dommages provoqués par Hylobius abietis L. (Coleoptera : Curculionidae) au pin maritime (Pinus pinaster Ait.) ont été évalués sur un test génétique de descendances maternelles soumis à différents traitements de fertilisation en Galice (NO Espagne). Le but était d'étudier la variation entre familles du niveau d'attaque de l'insecte et la possibilité d'inclure ce caractère dans le programme d'amélioration du pin maritime en Galice. Différents dégâts et symptômes ont été mesurés ainsi que la hauteur et le diamètre. Tous les traits évalués ont montré un effet famille très significatif et ils ont souvent corrélés entre eux. Les blessures évaluées au niveau de la tige du jeune plant montrent une héritabilité individuelle et familiale d'environ 0,2 et 0,8 respectivement. Le nombre de blessures sur la tige et la couleur des jeunes plants sont corrélés génétiquement. Il semble donc possible d'utiliser cette mesure de coloration, simple et subjective, pour évaluer la sensibilité du pin à l'hylobe. Nous avons aussi observé une corrélation génétique positive entre la croissance en diamètre et les dommages dus à H. abietis. Les familles les plus vigoureuses ont été les plus attaquées, ce qui limite les possibilités d'inclure la sensibilité à l'insecte dans le programme d'amélioration du pin maritime.This study was supported by the INIA project\ud RTA2-109.Peer reviewe

The installation of research or permanent plots is a very common task in growth and forest yield research. At young ages, tree height is the most commonly measured variable, so the location of individuals is necessary when repeated measures are taken and if spatial analysis is required. Identifying the coordinates of individual trees and re-measuring the height of all trees is difficult and particularly costly (in time and money). The data used comes from three Pinus pinaster Ait. and three Pinus radiata D. Don plantations of 0.8 ha, with an age ranging between 2 and 5 years and mean heights between 1 and 5 m. Five individual tree detection (ITD) methods are evaluated, based on the Canopy Height Model (CHM), where the height of each tree is identified, and its crown is segmented. Three CHM resolutions are used for each method. All algorithms used for individual tree detection (ITD) tend to underestimate the number of trees. The best results are obtained with the R package, ForestTools and rLiDAR. The best CHM resolution for identifying trees was always 10 cm. We did not detect any differences in the relative error (RE) between Pinus pinaster and Pinus radiata. We found a pattern in the ITD depending on the height of the trees to be detected: the accuracy is lower when detecting trees less than 1 m high than when detecting larger trees (RE close to 12% versus 1% for taller trees). Regarding the estimation of tree height, we can conclude that the use of the CHM to estimate height tends to underestimate its value, while the use of the point cloud presents practically unbiased results. The stakeout of forestry research plots and the re-measurement of individual tree heights is an operation that can be performed by UAV-based LiDAR scanning sensors. The individual geolocation of each tree and the measurement of heights versus pole and/or hypsometer measurement is highly accurate and cost-effective, especially when tree height reaches 1–1.5 m.

Key message: Genetic parameter estimates at age 12 years for trunk volume in Pinus pinaster displayed low to moderate heritability for growth and stem form, whereas wood properties showed high heritability. No correlation was detected between resistance to the nematode Bursaphelenchus xylophilus and growth, stem form, or wood properties. However, certain families stood out, showing favorable values across all traits, including resistance to the nematode. Context: The breeding program for Pinus pinaster should advance towards a second-generation breeding population based on volume, stem form, and resistance to Bursaphelenchus xylophilus, with the challenge of incorporating novel traits of importance. Aims: We focused on assessing the genetic parameters of growth, stem form, wood properties, and resistance to B. xylophilus as well as exploring the relationship between these traits. Methods: We evaluated 116 half-sib families at three ages (7, 12, and 17 years) in seven progeny trials established in 2005, analyzing growth, stem form, and wood traits. Resistance to B. xylophilus was assessed in 91 of the 116 half-sib families at age 2 by artificial inoculation tests under greenhouse conditions. Results: Advancing the selection age to 12 years proved to be feasible for volume selection in Galician P. pinaster. All traits, including resistance to B. xylophilus, showed potential for genetic improvement. Remarkably, resistance to B. xylophilus was not correlated to any other trait. Conclusion: Excluding the most susceptible families to B. xylophilus from the Galician P. pinaster breeding program would not result in a significant decrease in volume, stem form, or wood properties.