Purpose of Review: In this review, we synthesise current knowledge on trade-offs among traits in key fitness dimensions and identify major research gaps with the intention of laying the groundwork for a rapid advance in tree breeding for multiple objectives as a key contribution to the sustainability of planted forests in the future. Recent Findings: Trade-offs among growth, reproduction, defence, stress tolerance and product quality predicted theoretically have been reported experimentally in many breeding programmes. Among these trade-offs, the genetic linkage between resistance against biotic threats and growth (or other relevant traits) is particularly critical for the current and future management of forest genetic resources. Maintaining tree growth and wood quality in the novel environments of the future requires the assessment of genetic correlations of target traits with phenology, closely linked to survival to temperature extremes. Improving our current knowledge on the genetic trade-offs of drought tolerance as a breeding objective in forest trees obligates a more precise definition of both the specific traits and the experimental conditions. Published evidence suggests that common target traits in breeding programmes may trade-off with reproductive success and fire-adaptation, and the simultaneous improvement of growth and wood quality traits still remains as a constraint in traditional tree breeding. Summary: Changing environments combined with pests and diseases are challenging plantation forestry worldwide, which implies an urgent need to develop new improvement strategies to build the resilience of forestry for our future environments. It is essential to have a better understanding of how traits interact, especially those important for production, climate and biotic threat resilience, but much of the information is still missing. Since many key trade-offs are affected by the environment, we need new studies under novel environments to forecast levels of multi-trait integration in breeding populations.

The assessment of seed zones or regions of provenance (RoP) to preserve local adaptation of tree species is an effective tool for the correct management of forest reproductive materials. The RoP for a species or sub-species is the area or group of areas subject to sufficiently uniform ecological conditions in which stands or seed sources show similar phenotypic or genetic characters, taking into account altitudinal boundaries where appropriate. However, the delineation of RoPs is commonly based on estimates of intrinsic environmental homogeneity, mainly climate and/or soil characteristics. The integration of genetic data into RoP maps is an important strategy to obtain a sound tool for managing forest reproductive materials. A study on Quercus suber (cork oak) in Sardinia (Italy) was carried out with the aim of determining ecological regions of provenance, investigating the genetic diversity among populations at the regional scale and identifying possible areas of interest for valorising the available germplasm. Identification of these areas was performed by Reserve Selection Analysis, which allows to identify priority areas by assessing the minimum number of sites required to include all the genetic diversity estimated by genetic analysis. Four spatial clusters were obtained based on environmental data: the northern and northern-eastern parts of the island were included in the Northern RoP; the second RoP covered the western part; and the third RoP enclosed the south-eastern region. The last group was distributed on the central part of the island (Central RoP) and includes the higher elevations. The sampled populations showed a low differentiation among populations and low diversity. According to the Reserve Selection Analysis, four conservation priority areas were identified. These indications can be useful at the local level because these sites can be proposed as stands for seed collection for future plantations.

The genus Limonium includes over 300 species, about 200 of which originate in the Mediterranean basin. From a botanical point of view, several studies were carried out in order to clarify the phylogenetic relationships between species. Many of these studies, however, were not clear and exhaustive as they were often limited to restricted geographical areas. A collection of Limonium species, native to Europe, Caucasus, Asia and Africa, was set up at the CRA-VIV Pescia as part of the RGV-FAO Project. This collection includes about 70 accessions of 16 species found both in their habitat of origin and from seed companies. Plants were grown in unheated greenhouses. The aim of this work was to list and characterize the collection using both morphometric markers, provided by CPVO, and AFLP molecular markers. The use of morphometric parameters, which is essential for characterization of new cultivars, has been adapted for interspecific evaluation through the identification of species-specific parameters, i.e., type of inflorescence, calyx shape and colour, etc. Among 37 CPVO parameters, 9 have been considered for analysis. Biometric data and visual assessments were statistically elaborated by similarity matrix and cluster analysis. Use of AFLP molecular markers allowed a further discussion of the results obtained with morphometric analysis. Among 64 primer combinations, four have been selected and provided over 400 polymorfic bands. Electrophoretic profiles have been scored trough a suitable software (CrossChecker) and the resulted matrix has been elaborated by cluster analysis. Based on these analyses, dendrograms describing the phylogenetic relationships among 16 species were elaborated. Both morphometric and molecular analyses were effective in clarifying most of the phylogenetic relationships among the species of the Limonium collection.