Abstract• Among the traits of breeding interest for the common walnut tree Juglans regia L., characteristics such as timing of budbreak and leaf fall, water-use efficiency and growth performance are regarded as being of utmost relevance in Mediterranean conditions.• The authors evaluated intraspecific variation in δ 13 C (carbon isotope composition, surrogate of intrinsic water-use efficiency, WUE i ) for 22 J. regia families grown in a progeny test under supplementary irrigation, and investigated whether such variation correlated with climatic indicators of native habitats. The genetic relationships between δ 13 C, growth and phenology were also assessed during two consecutive years.• Overall, the most water-use-efficient families (i.e. with higher δ 13 C), which originated mainly from drought-prone provenance regions which have a high vapour pressure deficit and low rainfall, exhibited less height growth and smaller DBH. Using a stepwise regression procedure, δ 13 C was included as the main explanatory variable of genotypic variation in growth traits, together with growing season duration (for DBH in both years) and flushing (for height in 2007).• It was concluded that WUE i is largely unconnected to phenology effects in the explanation of growth performance for J. regia, therefore suggesting the opportunity of simultaneously selecting for low WUE i and extended growing period to maximise productivity in non-water-limited environments. Mots-clés :efficience d'utilisation de l'eau / climat méditerranéen / noyer / sélection / provenance Résumé -Variation génétique de la composition isotopique du carbone chez Juglans regia L. : relations avec la croissance, la phénologie et le climat d'origine.• Parmi les traits d'intérêt pour la sélection de noyer commun Juglans regia, des caractéristiques telles que la précocité de débourrement et la date de chute des feuilles, l'efficience d'utilisation de l'eau et la performance de croissance sont considérées comme étant importantes dans les conditions méditerranéennes.• Les auteurs ont évalué la variation intraspécifique de composition isotopique en 13C (δ 13 C, substitut de l'efficience intrinsèque d'utilisation de l'eau, WUE i ) dans 22 familles de Juglans regia cultivées dans un essai de descendance avec une irrigation d'appoint, et ils ont examiné si la variation était corrélée avec les indicateurs du climat des habitats d'origine. Les relations génétiques entre δ 13 C, croissance et phénologie ont également été évaluées au cours de deux années consécutives.• En général, les familles présentant les plus fortes valeurs de WUE i (c'est-à-dire avec le δ 13 C le plus élevé), qui proviennent essentiellement des régions de provenance à sécheresse élevée et à fort déficit de pression de vapeur et faibles précipitations, présentent une croissance en hauteur moindre et un plus faible diamètre à 1,3 m. En utilisant une procédure de régression par étapes, δ 13 C a été inclus en tant que principale variable explicative de la variation génotypique des caractéristiques de croissance, ...

The growing interest in broadleaf timber plantations in the Mediterranean area has promoted several studies focusing on the identification and characterization of variability sources in main timber-producing species. J. regia is one of these species, well-adapted to this area, but with freezing, damages registrations. Breeding focused on productive traits should include knowledge of adaptation, required to obtain a good selection capable of producing a suitable turnover in timber plantations. In this study, the features evaluated were autumn and winter frost hardiness and some vegetative traits on 22 half-sib J. regia progenies. Budsticks were exposed to sub-zero temperatures in a controlled chamber and using measurements of relative electrolyte content, the LT50 values (°C) were calculated by each individual. The study was carried out on seven-year-old progenies. The familiar heritability of autumn frost hardiness was 0.68, and on winter, it was 0.77. The autumn frost behaviour correlated genetically with the length of the growing season (0.574 ± 0.351), and both autumn and winter frost hardiness correlated inversely with secondary annual growth measured at breast height (−0.654 ± 0.259 and −0.740 ± 0.227, respectively). These results pointed that growth could therefore be improved without increasing the frost vulnerability. This should be important for growers, particularly under climate change conditions

Prunus avium is primarily cultivated for its fruit, sweet cherries. However, it is also used to produce high‐quality timber. In a P. avium seed orchard, gametophytic self‐incompatibility is a restriction for free pollen flow and should be considered when establishing basic forest materials. In this study, S‐locus diversity and cross‐incompatibility of wild cherry individuals in clonal banks established for breeding for timber production were investigated. Wild cherry trees (140) with outstanding forest growth habit, collected in northern Spain, grafted and planted in two clonal banks, were genotyped at the S‐locus. The self‐incompatibility S‐locus genes, S‐RNase and SFB, were analysed by PCR. Twenty‐two S‐haplotypes, resulting in 72 different S‐genotypes, were identified. The genotypes were grouped into 33 incompatibility groups and 39 unique genotypes. This initial S‐locus analysis revealed large genetic diversity of wild cherry trees from the Spanish northern deciduous forest, and provides useful information for seed orchard design. Wild P. avium displays significantly more genetic diversity than what is detected in local cultivars, revealing a narrowing of genetic diversity during local domestication.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Genotype and environment: two factors related to autumn cold hardiness on Persian walnut (Juglans regia L.

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