Place BIOGECO INRAE – University of Bordeaux, Talence campus.
Starting date: January 2026.
Supervisors: Marta Benito Garzón, Eduardo Vicente and Camille Lepoittevin (BIOGECO – E4E)
Recruitment process: Please send a cover letter and CV to eduardo.vicente-bartoli@inrae.fr by October 31, 2025. Selected applicants will be contacted for an interview.
Funding: EVOLTREE OPPORTUNITY 2024-2025, SUPERB H2020
Allowance: the monthly allowance is approximately 609-650 € /month (regulated trainee rate for 35h / week).
Required skills: M1 in ecology or similar fields, excellent modeling skills, good knowledge of R environment, team work capacity.
Languages: French and English.
We offer two M2 internships to study the process of physiological dormancy release in Pinus nigra J.F. Arnold seeds and its relationship with early fitness (germination, seedling growth and survival). The students will be based at the Talence Campus of the University of Bordeaux and will join an international research team with a very positive and friendly atmosphere. The internships are part of the European projects H2020 OPTFOREST and EVOLTREE OPPORTUNITY 2024-2025. Collaboration with colleagues from other countries involved in the project is also expected. See more details below.
Scientific context.
The first processes of early-life tree stages encompass germination, including dormancy release, as well as seedling emergence, survival, growth, and phenology. Many species inhabiting temperature-seasonal climates present physiological dormancy (PD; Rosbakh et al., 2023), i.e. their germination is prevented by endogenous physiological or metabolic processes. In this line, the seeds of many European conifer species have non-deep PD, meaning that, unless the mechanisms inducing dormancy are alleviated, seeds can only germinate within a narrow temperature range, with a reduced probability and at a slower rate. Particularly, for species inhabiting temperate and cold-seasonal climates, the process of PD breaking consist in a cold (3-5ºC) and moist period (cold stratification), which is normally meet at spring onset or when snow melts (Baskin and Baskin, 2001). Increasing winter and spring temperatures due to global warming will likely reduce the time window for cold stratification. This can have important impacts in the germination and regeneration capacity of European tree species with PD. As an adaptive trait, PD can change among species and populations (Kaye et al., 2018; Monemizadeh et al., 2021). Hence, global warming impacts on germination may vary greatly depending on the populations concerned.
Assessing dormancy variations across populations is therefore crucial to understand how global warming may affect the early stages of species with PD. Evaluating seed dormancy level requires a means to quantify the seed properties inducing PD. Up to now, this has been only done by indirect methods, such as testing different stratification periods along with destructive analyses to estimate the concentration of biochemicals involved in PD (Chen et al., 2024). However, near infrared (NIR) spectroscopy is a non-destructive and cost-effective alternative that allows the study of seed physical and chemical properties. Thanks to NIR spectroscopy, several studies have been able to evaluate seed viability (Dumont et al., 2015; Tigabu, 2003). NIR spectroscopy has also been used to discriminate between provenances in natural tree populations (Farhadi et al., 2017) and recently, we used it to predict germination phenology (Poughon et al., 2025), Accordingly, it could also be used to detect spectral variations associated to metabolic changes triggered by dormancy breaking. Nonetheless, this approach has not been previously explored.
In addition, our knowledge on how environmental alterations affect dormancy and germination is very limited (Seidl and Turner, 2022; Vicente and Benito Garzón, 2024), including how this may impact seedlings early-stage fitness (e.g. growth rate and survival). Indeed, the impacts of an incomplete dormancy release linked to reduced stratification windows may not be limited to germination probability and timing, but also extend to the subsequent life-stages. For instance, in Arabidopsis thaliana (non-deep PD), plants germinated from non-stratified seeds displayed lower rosette size and fecundity (Postma and Ågren, 2022). However, most of the existing studies addressing seed dormancy only focus on germination traits, so the links between dormancy release and seedlings’ fitness are currently unexplored.
Our project focus on Pinus nigra J.F. Arnold, a species with shallow PD and of important economic and ecological interest. The species is usually classified in main 4 subspecies from west to east in the Mediterranean basin: P. nigra salzmannii, P. nigra laricio, P. nigra nigra and P. nigra pallasiana (Caudullo et al., 2017; Olsson et al., 2020). The project will then use seed material of 4 populations: Spain, Italy, Bosnia and Cyprus. Each one, respectively, representing a P. nigra subspecies sector. The seeds are already collected and provided by TRAGSA (Spain, Spanish population, Francisco Lario), CNR-IBBR (Italy, Italian population, Maurizio Marchi), SFI (Slovenia, Bosnian and Cypriot populations, Marjana Westergren).
We offer the following internships:
M2 internship #1: Here, the student will apply NIR spectroscopy to discriminate between provenances in seedlots of Pinus nigra, to assess the spectral changes in the seeds associated to the process of dormancy breaking. NIR sampling will be performed during the first month of the internship at the INRAE facilities in Cestas (~20 min by car from the Talence campus), and will be closely supervised by Eduardo Vicente and Camille Lepoittevin. The obtained spectral signatures and the potential changes in the absorption bands will be analyzed using Partial Least Square Discriminant Analysis (PLSDA) to detect spectral differences linked to dormancy breaking and seed origin.
M2 internship #2: Here, the student will monitor germination and seedling emergence of Pinus nigra in three climatic chambers each one set at different temperature conditions. The seeds sown in the climatic chambers will be same previously used in the NIR sampling. The height of every seedling at the moment of first leaf emergence will also be measured. After 3 months from germination onset, seedling survival and growth will be monitored Cox proportional hazards models will be used to analyze germination and emergence timing. Generalized linear mixed models (GLMM) will be used to fit population based reaction norms of germination probability, seedling survival and growth.
References.
Baskin, C.C., Baskin, J.M., 2001. SEEDS Ecology, biogeograpghy, and evolution of dormancy and germination. Academic Press.
Caudullo, G., Welk, E., San-Miguel-Ayanz, J., 2017. Chorological maps for the main European woody species. Data in Brief 12, 662–666. https://doi.org/10.1016/j.dib.2017.05.007
Chen, Y., Liu, P., Wang, Y., Xu, T., Li, J., Pei, Z., Zhang, Y., Li, G., Yang, Q., 2024. Characteristic of epicotyl dormancy and its hormonal regulation in Chinese cork oak (Quercus variabilis). Plant Physiology and Biochemistry 215, 109041. https://doi.org/10.1016/j.plaphy.2024.109041
Dumont, J., Hirvonen, T., Heikkinen, V., Mistretta, M., Granlund, L., Himanen, K., Fauch, L., Porali, I., Hiltunen, J., Keski-Saari, S., Nygren, M., Oksanen, E., Hauta-Kasari, M., Keinänen, M., 2015. Thermal and hyperspectral imaging for Norway spruce (Picea abies) seeds screening. Computers and Electronics in Agriculture 116. https://doi.org/10.1016/j.compag.2015.06.010
Farhadi, M., Tigabu, M., Pietrzykowski, M., 2017. Application of near infrared spectroscopy for authentication of Picea abies seed provenance. New Forests 48, 629–642. https://doi.org/10.1007/s11056-017-9589-1
Kaye, T.N., Sandlin, I.J., Bahm, M.A., 2018. Seed dormancy and germination vary within and among species of milkweeds. AoB PLANTS 10, ply018. https://doi.org/10.1093/aobpla/ply018
Monemizadeh, Z., Ghaderi-Far, F., Sadeghipour, H.R., Siahmarguee, A., Soltani, E., Torabi, B., Baskin, C.C., 2021. Variation in seed dormancy and germination among populations of Silybum marianum (Asteraceae). Plant Species Biology 36, 412–424. https://doi.org/10.1111/1442-1984.12326
Olsson, S., Grivet, D., Cattonaro, F., Vendramin, V., Giovannelli, G., Scotti-Saintagne, C., Vendramin, G.G., Fady, B., 2020. Evolutionary relevance of lineages in the European black pine (Pinus nigra) in the transcriptomic era. Tree Genetics & Genomes 16, 30. https://doi.org/10.1007/s11295-020-1424-8
Postma, F.M., Ågren, J., 2022. Effects of primary seed dormancy on lifetime fitness of Arabidopsis thaliana in the field. Annals of Botany 129, 795–808. https://doi.org/10.1093/aob/mcac010
Poughon, J., Lepoittevin, C., Vicente, E., Carme, M., Mihai, G., Lario Leza, F., Piotti, A., Avanzi, C., Marchi, M., Vendramin, G.G., Scotti-Saintagne, C., Fady, B., Teyssier, C., Benito Garzón, M., 2025. Near-infrared spectroscopy-based models correctly classify Abies alba seed origin and predict germination properties. Forest Ecology and Management 597, 123068. https://doi.org/10.1016/j.foreco.2025.123068
Rosbakh, S., Carta, A., Fernández‐Pascual, E., Phartyal, S.S., Dayrell, R.L.C., Mattana, E., Saatkamp, A., Vandelook, F., Baskin, J., Baskin, C., 2023. Global seed dormancy patterns are driven by macroclimate but not fire regime. New Phytologist 240, 555–564. https://doi.org/10.1111/nph.19173
Seidl, R., Turner, M.G., 2022. Post-disturbance reorganization of forest ecosystems in a changing world. Proceedings of the National Academy of Sciences 119, e2202190119. https://doi.org/10.1073/pnas.2202190119
Tigabu, M., 2003. Characterization of forest tree seed quality with near infrared spectroscopy and multivariate analysis. Dept. of Silviculture, Swedish Univ. of Agricultural Sciences.
Vicente, E., Benito Garzón, M., 2024. Tree Germination Sensitivity to Increasing Temperatures: A Global Meta‐Analysis Across Biomes, Species and Populations. Global Ecol Biogeogr e13921. https://doi.org/10.1111/geb.13921
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