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Individual and family heritabilities and juvenile–mature genetic correlations were estimated for growth and biomass traits recorded in treatment with optimal and limiting water and/or nutrient availability to study how the different growth environments affected genetic parameter estimates. Thirty open-pollinated families, randomly selected among the 58 families used in field progeny tests in Galicia, were cultivated for 30 weeks in a climatic chamber under controlled conditions. Two water regimes (high and low water supply) combined with two nutrient regimes (high and low nutrient supply) were applied by subirrigation. Several growth, branching and dry mass traits were assessed 30 weeks after sowing and compared with field performance (height, diameter and volume) of 4-year-old progeny tests established at three different sites in Galicia (NW Spain). Both the irrigation and the fertilization treatments had a strong effect in all the assessed traits except irrigation for the number of branches. Heritabilities for growth and biomass traits were moderate to high (0.13–0.77) in individual treatments. However, when analyzing all treatments together, the impact of the family × treatment interactions led to a reduction (0.20–0.35) in the heritability estimates. The results indicated that the genotype × water and genotype × nutrient interactions may be important and could not be ignored in the Galician radiata pine breeding program. Climatic chamber–field correlations were different between different traits measured at climatic chamber experiments and the three field tests. The correlations were larger with the well-watered treatments, suggesting that further development of early testing methods for radiata pine in Galicia should include treatments with no limiting water availability.

[EN] Cherry leaf spot (Blumeriella jaapii (Rehm) Arx.) is a very serious disease of wild cherry (Prunus avium L.), which produces premature leaf defoliation and vigor decrease. In two clonal seed orchards of P. avium naturally infected by B. jaapii, spatial heterogeneity and autocorrelation of neighbor damage caused by cherry leaf spot impeded proper analysis of the fungus incidence. The iterative spatial analysis (ISA), based on variography and kriging, was successfully used to eliminate the effect of this spatial heterogeneity in analysis of genetic variation in susceptibility to B. jaapii. Significant differences among P. avium clones were found, with moderate to high broad-sense heritability estimates. Genetic by environment interactions, although significant, were not quantitatively important. A strong relationship between leaf spot susceptibility and bud burst was found. However, other factors must be affecting the genetic variation in leaf spot susceptibility, as differences among clones remained highly significant when considering the bud burst as a covariate in the genetic model., [FR] Blumeriella jaapii (Rehm) Arx. est une des causes principales du dépérissement du merisier (Prunus avium L.) : il produit une défoliation prématurée et réduit la vigueur des arbres. Dans deux vergers à graines de clones de merisier naturellement infectés par B. jaapii, l’hétérogénité spatiale des dégâts et l’autocorrélation entre voisins empêchent une analyse correcte de l’incidence du champignon. Afin d’éliminer ces effets et d’étudier correctement la variabilité génétique de la susceptibilité au champignon, on a utilisé avec succès l’analyse itérative spatiale (ISA), basée sur la variographie et le krigeage. Des différences significatives entre clones existent pour la sensibilité au champignon. L’héritabilité clonale pour ce caractère est modérée à forte. Bien que l’interaction clone × site soit significative, elle n’est pas quantitativement importante. Par ailleurs, on a trouvé une relation étroite entre la susceptibilité au champignon et le débourrement végétatif. Néanmoins, d’autres facteurs doivent affecter la variabilité génétique à la susceptibilité, car les différences entre clones restent très significatives même quand on utilise le débourrement comme covariable dans le modèle statistique

A Pinus radiata progeny trial was established in 2003 on three low fertility sites in Galicia to study the relevance of genotype×fertilization interaction. At each site, twenty seven open pollinated families derived from plus trees selected in mature plantations in Galicia (NW Spain) were planted under 9 fertilization treatments following a split-plot design. One year after planting, P and Mg fertilization significantly increased height growth whereas N did not affect or even significantly reduced height growth. Fertilization×site interaction was not significant indicating parallel responses to fertilization in the three sites. Fertilization × genotype interaction was significant in only one site, suggesting some genetic variation in the nutrient use efficiency among the studied genotypes. However, the lack of a significant interaction in the other two sites, and the lack of consistence among the genotypic stability in relation to fertilization across sites, hinder the possibility of breeding in relation to the nutrient efficiency of the genotypes. Indications for further research are given.

[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.