Elena Torres

Ozone (O3) and temperature are affecting key stages for plant development and population maintenance. Effects of O3 and temperature on growth, flowering, seed production and development were studied in six Mediterranean alpine species. Using an open chamber facility (OTC), plants were subjected to four different O3 treatments that reproduced pre-industrial, current, and projected future O3 levels in their natural habitats, and one temperature treatment. Vegetative growth was increased by O3 in Erodium paularense and by temperature in Silene ciliata. Generally, O3 delayed flowering onset and peak, while temperature advance them. Flowering duration was reduced by O3 but increased by temperature. O3 exposure reduced the seed numbers in Erysimun penyalarense and E. paularense, but increased them in Jurinea humilis and S. ciliata. O3 also reduced seed weight in E. paularense but enhanced seedling survival in S. ciliata. In overall, the lack of response in vegetative growth could lead the assumption that these species are tolerant to O3. However, the O3 and temperature contrasting effects on flower phenology effects may hinder the adaptation of these species to the soil water deficit. In addition, lower seed number and seed weight may exacerbate the declining of some species, reducing the biodiversity of these mountains.

Climate change may hinder species' ability to evolutionarily adapt to environmental shifts. Assisted gene flow, introducing adaptive alleles into target populations, could be a viable solution for keystone species. Our study aimed to evaluate the benefits and limitations of assisted gene flow in enhancing the evolutionary potential of Lupinus angustifolius L. (Fabaceae), considering both phenotypic and genomic perspectives. We collected seeds from four populations in Spain at two latitudes (north and south), and grew them in a common garden. We used pollen from southern individuals to pollinate northern plants and create an F1 gene flow line that would advance its flowering onset. In the next season, we allowed F1 plants to self‐pollinate creating an F2 self‐pollination line. We also created a backcross line by pollinating control northern plants with pollen from F1 plants. We measured flowering onset, reproductive success, and other plant traits in all resulting lines. In parallel, we sequenced genes related to reproduction, growth, stress, nitrogen, and alkaloids. All gene flow‐derived lines flowered significantly earlier than the control lines from the northern populations. F1 gene flow line plants produced heavier seeds and had a lower shoot growth than those from the northern control lines. Genomic analyses identified 36 outlier SNPs between the control and the F1 gene flow lines, associated with differences in flowering onset, seed weight, and shoot growth. These results underscore that assisted gene flow can enhance a population's evolutionary potential by altering specific traits. However, altering one trait may impact others in a way that depends on the intrinsic characteristics of each population.

Climate change poses a novel threat to biodiversity that urgently requires the development of adequate conservation strategies. Living organisms respond to environmental change by migrating to locations where their ecological niche is preserved or by adapting to the new environment. While the first response has been used to develop, discuss and implement the strategy of assisted migration, facilitated adaptation is only beginning to be considered as a potential approach. Here, we present a review of the conceptual framework for facilitated adaptation, integrating advances and methodologies from different disciplines. Briefly, facilitated adaptation involves a population reinforcement that introduces beneficial alleles to enable the evolutionary adaptation of a focal population to pressing environmental conditions. To this purpose, we propose two methodological approaches. The first one (called pre-existing adaptation approach) is based on using pre-adapted genotypes existing in the focal population, in other populations, or even in closely related species. The second approach (called de novo adaptation approach) aims to generate new pre-adapted genotypes from the diversity present in the species through artificial selection. For each approach, we present a stage-by-stage procedure, with some techniques that can be used for its implementation. The associated risks and difficulties of each approach are also discussed.

In the present framework of global warming, it is unclear whether evolutionary adaptation can happen quick enough to preserve the persistence of many species. Specifically, we lack knowledge about the adaptive potential of the different populations in relation to the various constraints that may hamper particular adaptations. There is evidence indicating that early flowering often provides an adaptive advantage to plants in temperate zones in response to global warming. Thus, the objective of this study was to assess the adaptive potential for advancing flowering onset in Lupinus angustifolius L. (Fabaceae). Seeds from four populations from two contrasting latitudes in Spain were collected and sown in a common garden environment. Selecting the 25% of the individuals that flowered earlier in the first generation, over three generations, three different early flowering selection lines were established, involving both self‐crosses and outcrosses. All artificial selection lines advanced their flowering significantly with respect to the control line in the northernmost populations, but not in the southern ones. Selection lines obtained from outcrossing had a greater advancement in flowering than those from self‐crossing. No differences were found in the number or weight of the seeds produced between control and artificial selection lines, probably because plants in the common garden were drip irrigated. These results suggest that northern populations may have a greater adaptive potential and that southern populations may be more vulnerable in the context of climate warming. However, earlier flowering was also associated with changes in other traits (height, biomass, shoot growth, specific leaflet area, and leaflet dry matter content), and the effects of these changes varied greatly depending on the latitude of the population and selection line. Assessments of the ability of populations to cope with climate change through this and other approaches are essential to manage species and populations in a more efficient way.

Orchid seeds are presumably dispersed by wind due to their very small size and thus can potentially travel long distances. However, the few related studies indicate that seeds fall close to their mother plants. Because seed dispersal and colonization patterns can have relevant consequences for long-term species persistence, we assessed the fine-scale genetic structure of the epiphytic orchid Epidendrum rhopalostele to provide insight into these patterns. All individuals in the studied population were georeferenced and genotyped with AFLP-markers. Genetic structure was evaluated at two levels (forest and tree) using three approaches: principal coordinates analysis, model-based clustering, and spatial autocorrelation analysis. Results showed two genetic groups, composed of individuals from almost every tree with orchids. Spatial autocorrelation analysis at the forest level found no significant genetic structure when all individuals were considered, but a pattern of genetic patches was revealed when the analysis was performed separately for each group. Genetic patches had an estimated diameter of 4 m and were composed of individuals from more than one tree. A weak genetic structure was detected at the tree level at distances less than 1.5 m. These results suggest that many seeds fall close to the mother plant and become established in the same host tree. Additionally, a sequential colonization process seems to be the predominant mode of expansion, whereby progeny from orchids in one tree colonize neighboring trees. Thus, the existence of two distinct genetic groups and the presence of genetic patches should be considered when seed sampling for ex situ conservation.

• Premise of the study: The presence of compatible fungi is necessary for epiphytic orchid recruitment. Thus, identifying associated mycorrhizal fungi at the population level is essential for orchid conservation. Recruitment patterns may also be conditioned by factors such as seed dispersal range and specific environmental characteristics.• Methods: In a forest plot, all trees with a diameter at breast height >1 cm and all individuals of the epiphytic orchid Epidendrum rhopalostele were identified and mapped. Additionally, one flowering individual of E. rhopalostele per each host tree was randomly selected for root sampling and DNA extraction.• Key results: A total of 239 E. rhopalostele individuals were located in 25 of the 714 potential host trees. Light microscopy of sampled roots showed mycorrhizal fungi in 22 of the 25 sampled orchids. Phylogenetic analysis of ITS1‐5.8S‐ITS2 sequences yielded two Tulasnella clades. In four cases, plants were found to be associated with both clades. The difference between univariate and bivariate K functions was consistent with the random labeling null model at all spatial scales, indicating that trees hosting clades A and B of Tulasnella are not spatially segregated. The analysis of the inhomogenous K function showed that host trees are not clustered, suggesting no limitations to population‐scale dispersal. χ² analysis of contingency tables showed that E. rhopalostele is more frequent on dead trees than expected.• Conclusions: Epidendrum rhopalostele establishes mycorrhizal associations with at least two different Tulasnella species. The analysis of the distribution patterns of this orchid suggests a microsite preference for dead trees and no seed dispersal limitation.

The present paper reviews the use of ecogeographical studies in the efficient conservation and utilization of plant genetic resources. While the use of genotypic information in agrobiodiversity studies has experienced a rapid boost during the last two decades, the use of environmental information on the collecting sites of the conserved germplasm (i.e., ecogeographical characterization) has gained importance in a more gradual way. Today we know that ecogeographical characterization reveals the adaptive range of species conserved and shows the most important environmental factors or variables for adaptation. Progress in ecogeographical characterization has been helped by the development and popularization of geographic information systems (GIS) software applications and environmental data arranged in layers compatible with such applications. GIS are useful to manage and analyze georeferenced data, such as passport collection data and environmental variables. Thus, GIS have become the best tool to perform ecogeographical analyses. Other related tools such as species distribution models or gap analysis can be easily integrated in ecogeographical analysis, offering improved results. As a result, GIS, related tools and ecogeographical analysis can be useful in a wide range of applications in the collection, conservation, characterization, documentation and utilization of plant genetic resources.