Kremer, Antoine. 2017. Adaptive and plastic responses of Quercus petraea populations to climate across Europe. Global Change Biology, 23 (7). 2831-2847. 10.1111/gcb.13576 Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. Accepted ArticleThis article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/gcb.13576 This article is protected by copyright. All rights reserved. Accepted ArticleThis article is protected by copyright. All rights reserved. Accepted ArticleThis article is protected by copyright. All rights reserved. †Corresponding author: E-mail: antoine.kremer@pierroton.inra.fr Phone: + (33) 5 5712- 2832.Keywords: Climatic change, Climatic transfer distance, Mixed model, Quercus petraea, Survival, Tree growth.Paper Type: Primary Research. AbstractHow temperate forests will respond to climate change is uncertain; projections range from severe decline to increased growth. We conducted field tests of sessile oak (Quercus petraea), a widespread keystone European forest tree species, including more than 150,000 trees sourced from 116 geographically diverse populations. The tests were planted on 23 field sites in six European countries, in order to expose them to a wide range of climates, including sites reflecting future warmer and drier climates. By assessing tree height and survival, our objectives were twofold: (1) to identify the source of differential population responses to climate (genetic differentiation due to past divergent climatic selection versus plastic responses to ongoing climate change), (2) to explore which climatic variables (temperature or precipitation) trigger the population responses. Tree growth and survival were modeled for contemporary climate and then projected using data from four regional climate models for years 2071-2100, using two greenhouse gas concentration trajectory scenarios each. Overall results indicated a moderate response of tree height and survival to climate variation, with changes in dryness (either annual or during the growing season) Accepted ArticleThis article is protected by copyright. All rights reserved.explaining the major part of the response. Whilst, on average, populations exhibited local adaptation, there was significant clinal population differentiation for height growth with winter temperature at the site of origin. The most moderate climate model (HIRHAM5-EC; rcp4.5) predicted minor decreases in height and survival, whilst the most extreme model (CCLM4-GEM2-ES; rcp8.5) predicted large decreases in survival and growth for southern and southeastern edge populations (Hungary and Turkey). Other non-marginal populations with continental climate...

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Reliable methods for clone identification are desired to characterise and distinguish breeding products within the genus Populus L. (Salicaceae). Ten nuclear microsatellite loci (PMGC14, PMGC456, PMGC2163, PTR2, PTR7, WPMS05, WPMS09, WPMS14, WPMS15 and WPMS20) were applied on a clone collection with several species and hybrids belonging to the sections Tacamahaca (balsam poplars), Aigeiros (black poplars, cottonwoods) and Populus (white poplars and aspens) and intersectional hybrids between black and balsam poplars. The members of the different sections and species do not always share their allelic ladders. Some shifts of one or two nucleotides in allele length were observed for several loci. This could be explained by nucleotide sequence differences in the flanking regions of loci in diverse taxonomic groups. Such shifts of allelic ladders result in irregular patterns in hybrid genotypes. The set of loci should have a sufficient amount of variation for a differentiation between clones, even if they are full siblings originating from crossing experiments.

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Plant-associated Stenotrophomonas isolates have great potential for plant growth promotion, especially under stress conditions, due to their ability to promote tolerance to abiotic stresses such as salinity or drought. The endophytic strain Stenotrophomonas sp. 169, isolated from a field-grown poplar, increased the growth of inoculated in vitro plants, with a particular effect on root development, and was able to stimulate the rooting of poplar cuttings in the greenhouse. The strain produced high amounts of the plant growth-stimulating hormone auxin under in vitro conditions. The comparison of the 16S rRNA gene sequences and the phylogenetic analysis of the core genomes showed a close relationship to Stenotrophomonas chelatiphaga and a clear separation from Stenotrophomonas maltophilia. Whole genome sequence analysis revealed functional genes potentially associated with attachment and plant colonization, growth promotion, and stress protection. In detail, an extensive set of genes for twitching motility, chemotaxis, flagella biosynthesis, and the ability to form biofilms, which are connected with host plant colonization, could be identified in the genome of strain 169. The production of indole-3-acetic acid and the presence of genes for auxin biosynthesis pathways and the spermidine pathway could explain the ability to promote plant growth. Furthermore, the genome contained genes encoding for features related to the production of different osmoprotective molecules and enzymes mediating the regulation of stress tolerance and the ability of bacteria to quickly adapt to changing environments. Overall, the results of physiological tests and genome analysis demonstrated the capability of endophytic strain 169 to promote plant growth. In contrast to related species, strain 169 can be considered non-pathogenic and suitable for biotechnology applications.