A Coruña, Spain


A Coruña, Spain
Time filter
Source Type

de Miguel M.,INIA CIFOR. Ctra | de Miguel M.,Technical University of Madrid | Cabezas J.-A.,INIA CIFOR. Ctra | Cabezas J.-A.,Technical University of Madrid | And 19 more authors.
BMC Genomics | Year: 2014

Background: Understanding molecular mechanisms that control photosynthesis and water use efficiency in response to drought is crucial for plant species from dry areas. This study aimed to identify QTL for these traits in a Mediterranean conifer and tested their stability under drought.Results: High density linkage maps for Pinus pinaster were used in the detection of QTL for photosynthesis and water use efficiency at three water irrigation regimes. A total of 28 significant and 27 suggestive QTL were found. QTL detected for photochemical traits accounted for the higher percentage of phenotypic variance. Functional annotation of genes within the QTL suggested 58 candidate genes for the analyzed traits. Allele association analysis in selected candidate genes showed three SNPs located in a MYB transcription factor that were significantly associated with efficiency of energy capture by open PSII reaction centers and specific leaf area.Conclusions: The integration of QTL mapping of functional traits, genome annotation and allele association yielded several candidate genes involved with molecular control of photosynthesis and water use efficiency in response to drought in a conifer species. The results obtained highlight the importance of maintaining the integrity of the photochemical machinery in P. pinaster drought response. © 2014 de Miguel et al.; licensee BioMed Central Ltd.

Mayoral C.,INIA CIFOR Ctra | Pardos M.,INIA CIFOR Ctra | Sanchez-Gonzalez M.,INIA CIFOR Ctra | Brendel O.,University of Lorraine | Pita P.,Technical University of Madrid
Forest Ecology and Management | Year: 2016

The ability of trees to grow and survive during periods of water scarcity is determined by the water use strategy of each individual. In this study we evaluated how water use strategies can influence the establishment phase of three coexisting species in forests where harvesting intensity and silvicultural interventions have been reduced over recent decades. We conducted a greenhouse experiment between February and July, applying two watering regimes (moist and dry) to current year seedlings in 1.5 m high pots to avoid root growth constraint. At the same time, the physiological performance of seedlings of the same species was monitored under natural conditions in the field over a period of decreasing soil moisture. Our results indicated that resprouter species allocated more than 40% of total biomass to roots whereas the non-resprouter P. pinea allocated only 26%. The plasticity index for the root traits was highest in Q. ilex, in which the highest stomatal conductance was measured in early summer. The slowest growth and lowest root plasticity, root hydraulic conductance and leaf water potential were measured in J. oxycedrus. The three species exhibited a positive carbon balance under low water availability. Coexisting species displayed a continuum in the water use strategies adopted. P. pinea would be the least competitive species under the forecasted increasing drought conditions in contrast to J. oxycedrus, which presents traits more suited to coping with droughts. © 2016 Elsevier B.V.

Mayoral C.,INIA CIFOR Ctra | Strimbeck R.,Norwegian University of Science and Technology | Sanchez-Gonzalez M.,INIA CIFOR Ctra | Calama R.,INIA CIFOR Ctra | Pardos M.,INIA CIFOR Ctra
Trees - Structure and Function | Year: 2015

Key message: The effect of unexpected low temperature on coexisting species in inland locations was examined; frost tolerance simulation over a 2-year period was used to determine bottlenecks where competition can arise. Abstract: The effect of frost events on natural regeneration of Mediterranean mixed forests under a scenario of climate change is not well known. The expected increase in mean annual temperature and the greater inter- and intra-annual variability in frosts occurrence can significantly damage natural regeneration leading to death, with a decisive effect on species composition and forest dynamics. We investigated seasonal variations in frost tolerance of three Mediterranean species (Pinus pinea, Quercus ilex and Juniperus oxycedrus) co-occurring in inland locations in Spain. Our aim was to assess seasonal inter-specific differences in frost sensitivity or tolerance. First, we applied the relative electrolyte leakage method (REL) to estimate the frost tolerance of these species every 3–4 weeks during the 9-month period in which frost events can occur in a year. Second, we explored the REL relationship with environmental variables impacting frost acclimation/deacclimation, i.e., absolute minimum and maximum temperatures and photoperiod. Third, we built a REL model to predict seasonal variations in REL performance of young trees. We simulated REL through a 2-year period, thus defining seasonal bottlenecks in which the dynamics of regeneration can be affected by frost events. Our results showed contrasting behaviors between species, highlighting a greater sensitivity to cold of P. pinea compared to the other two species. The three species are most vulnerable in autumn; however, the different strategies to cope with unfavorable conditions adopted by Q. ilex and J. oxycedrus (e.g., stress tolerance and/or resprouting ability) give these species a competitive advantage over P. pinea. © 2015, Springer-Verlag Berlin Heidelberg.

PubMed | Aix - Marseille University, University of Barcelona, The Second University of Naples and INIA CIFOR. Ctra
Type: | Journal: Global change biology | Year: 2016

Forest performance is challenged by climate change but higher atmospheric [CO

Mayoral C.,INIA CIFOR Ctra | Calama R.,INIA CIFOR Ctra | Sanchez-Gonzalez M.,INIA CIFOR Ctra | Pardos M.,INIA CIFOR Ctra
New Forests | Year: 2015

The composition of Mediterranean forests is expected to vary with ongoing changes in climate and land use. To gain a clearer understanding of the response to global change of growth and survival during regeneration it is necessary to take a closer look at the ecophysiological traits underlying seedling performance. Gas exchange, leaf water potential, chlorophyll fluorescence, soil moisture, temperature and global site factor were measured over 1 year in naturally regenerated young trees of three coexisting species (Pinus pinea, Quercus ilex and Juniperus oxycedrus) in two stands of different density. We modelled the photosynthetic response of plants to micro-climatic conditions via the parameterization of the non-rectangular hyperbolic model of photosynthesis, which relates gross photosynthesis to incident light through three biochemical parameters, and the subsequent expansion of these parameters as a function of environmental variables (light environment, soil moisture and temperature). We investigated the relationship between different photosynthetic performance and the species-specific strategies to cope with stress (stress tolerant or avoiders). The optimal light environment, defined through the global site factor (GSF), and the regeneration niche to maximize carbon assimilation differed between the three species. P. pinea showed high sensitivity to water availability in agreement with a drought avoidance strategy, attaining the maximum photosynthetic capacity of the three species following the spring rainfall. Q. ilex was the most thermophilic and light-demanding of the species. Under high light conditions, J. oxycedrus was more drought tolerant and displayed higher net CO2 assimilation than P. pinea over the course of a growing period. Optimal locations for P. pinea regeneration are below-crown environments, while for J. oxycedrus regeneration the optimal locations are open gaps. Q. ilex regeneration occupy open gaps where the other two species are unable to establish themselves because of excessive light, temperature or very low water availability. Competition between species will occur under a canopy gap fraction of 0.5. Higher GSF values will exclusively favour the regeneration of Q. ilex. © 2015, Springer Science+Business Media Dordrecht.

Loading INIA CIFOR Ctra collaborators
Loading INIA CIFOR Ctra collaborators