Biology subjects

Vila-Vicosa, C.

Publications and source records attributed to Vila-Vicosa, C..

4 recordsLinked to original sources

bioRxiv2026

Recurrent Hermaphroditism and Sex-Biased ABCDE Gene Expression Reveal Latent Floral Plasticity in the Pedunculate Oak Lineage (Q.robur s.l.)

Background and AimsThe development of unisexual flowers relies on the tight coordination of flower organ identity and sex determination. The genus Quercus is typically considered strictly monoecious, bearing fully segregated male and female flowers within the same individual tree. However, several reports of atypical flowering across the genus challenge this canonical view, suggesting that flowering in oaks may be more flexible than traditionally assumed. In this work, the dynamics of flower development in Quercus orocantabrica were examined to correlate contrasting floral morphologies with divergent molecular profiles. MethodsThe flowering phenology of Q. orocantabrica trees was closely monitored over several individuals and years, together with a detailed floral morphological analysis of male, female and atypical flowers. Key floral homeotic gene homologues were identified, and their expression assayed in the development of different flowers. Key ResultsRecurrent and widespread hermaphroditic flowering was detected in several Q. orocantabrica trees, frequently associated with unseasonal flowering events. Gene expression analysis of male, female and hermaphroditic flowers revealed a sex-biased expression of Q. orocantabrica B- and C-class genes, with the B-class gene QoPI in particular being tightly associated with the presence of fully-developed stamens. In addition, the expression of the C-class gene QoSHP contrasted with reports in other Fagaceae, highlighting a potential functional divergence of the C/D-class lineage within the family. ConclusionsThe results here depicted indicate that the dynamics of floral sex identity in oaks are more plastic than traditionally assumed, supporting a reinterpretation of oak reproductive biology based on a versatile and resilient framework responsive to different developmental contexts.

plant biology↗

bioRxiv2023

Predicting the timing of ecological phenomena across regions using citizen science data

Spatial predictions of intra-annual ecological variation enhance ecological understanding and inform decision-making. Unfortunately, it is often challenging to use statistical or machine learning techniques to make such predictions, due to the scarcity of systematic, long-term observational data. Conversely, opportunistic time-stamped observation records, supported by highly informative data such as photographs, are increasingly available for diverse ecological phenomena in many regions. However, a general framework for predicting such phenomena using opportunistic data remains elusive. Here, we introduce a novel framework that leverages the concept of relative phenological niche to model observation records as a sample of temporal environmental conditions in which the represented ecological phenomenon occurs. We demonstrate its application using two distinct, management-relevant, ecological events: the emergence of the adult stage of the invasive Japanese beetle (Popillia japonica), and of fruiting bodies of the winter chanterelle mushroom (Craterellus tubaeformis). The framework accounts for spatial and temporal biases in observation data, and it contrasts the temporal environmental conditions (e.g., in temperature, precipitation, wind speed, etc.) associated with the observation of these events to those available in their occurrence locations. To discriminate between the two sets of conditions, we employ machine-learning algorithms (boosted regression trees and random forests). The proposed approach can accurately predict the temporal dynamics of ecological events across large geographical scales. Specifically, it successfully predicted the intra-annual timing of occurrence of adult Japanese beetles and of winter chanterelle mushrooms across Europe and North America. We further validate the approach by successfully predicting the timing of occurrence of adult Japanese beetles in Northern Italy, a recent hotspot of invasion in continental Europe, and the winter chanterelle mushroom in Denmark, a country with a high number of records of this mushroom. These results were also largely insensitive to temporal bias in recording effort. Our results highlight the potential of opportunistic observation data to predict the temporal variation of a wide range of ecological phenomena in near real-time. Furthermore, the conceptual and methodological framework is intuitive and easily applicable for the large number of ecologists already using machine-learning and statistical-based predictive approaches.

ecology↗

bioRxiv2022

The Amidella clade in Europe (Amanita Pers., Basidiomycota: Amanitaceae): clarification of the contentious Amanita valens and the importance of taxon-specific PCR primers for identification

The species in genus Amanita section Amidella form a well-defined clade, but some taxa remain difficult to discriminate. In particular, the concept of Amanita valens (E.-J. Gilbert) Bertault remains controversial. To understand the phylogenetic placement of a set of collections from South Portugal with a novel nrDNA barcode, we have obtained nrDNA sequences for previously unassessed type collections. The taxon formerly described as Amanita curtipes f. pseudovalens Neville & Poumarat is interpreted as a separate species, Amanita pseudovalens (Neville & Poumarat) Arraiano-Castilho et al. comb. et stat. nov., and is genetically indistinct from the Portuguese collections, thus clarifying their taxonomic context. However, our collections are morphologically and ecologically distinct (respectively, ellipsoid to oblong basidiospores and association with Cistus on acidic schist soils), and are proposed as a new variety, Amanita pseudovalens var. tartessiana Arraiano-Castilho et al.. These developments also enable a better diagnosis of Amidella taxa in Europe, a progress that is most decisive for the late Winter to Spring season collections, and identification keys are proposed. However, the co-occurrence and morphological similarity of the new variety, in comparison with the prized edible Amanita ponderosa Malencon & Heim, could leave some collections of either taxa unresolved. Thus, a molecular marker approach was developed, to provide a clear and cost-effective identification aid to complement the keys. The proposed diagnostic tools can be applied toward a review of European Amidella taxa chorology from existing records, conserved materials, and future collections. Evolutionary convergence may contribute to the determination difficulties in the Amidella clade.

evolutionary biology↗

bioRxiv2019

Chemical variations in Quercus pollen as a tool for taxonomic identification: implications for long-term ecological and biogeographic research

vi.AimFossil pollen is an important tool for understanding biogeographic patterns in the past, but the taxonomic resolution of the fossil-pollen record may be limited to genus or even family level. Chemical analysis of pollen grains has the potential to increase the taxonomic resolution of pollen, but present-day chemical variability is poorly understood. This study aims to investigate whether a phylogenetic signal is present in the chemical variations of Quercus L. pollen and to assess the prospects of chemical techniques for identification in biogeographic research. LocationPortugal TaxonSix taxa (five species, one subspecies) of Quercus L., Q. faginea, Q. robur, Q. robur ssp. estremadurensis, Q. coccifera, Q. rotundifolia and Q. suber belonging to three sections: Cerris, Ilex, and Quercus (Denk, Grimm, Manos, Deng, & Hipp, 2017) MethodsWe collected pollen samples from 297 individual Quercus trees across a 4{degrees} ([~]450 km) latitudinal gradient and determined chemical differences using Fourier-transform infrared spectroscopy (FTIR). We used canonical powered partial least-squares regression (CPPLS) and discriminant analysis to describe within- and between-species chemical variability. ResultsWe find clear differences in the FTIR spectra from Quercus pollen at the section level (Cerris: [~]98%; Ilex: [~]100%; Quercus: [~]97%). Successful discrimination is based on spectral signals related to lipids and sporopollenins. However, discrimination of species within individual Quercus sections is more difficult: overall, species recall is [~]76% and species misidentifications within sections lie between 18% and 31% of the test-set. Main ConclusionsOur results demonstrate that subgenus level differentiation of Quercus pollen is possible using FTIR methods, with successful classification at the section level. This indicates that operator-independent FTIR approaches can surpass traditional morphological techniques using the light microscope. Our results have implications both for providing new insights into past colonisation pathways of Quercus, and likewise for forecasting future responses to climate change. However, before FTIR techniques can be applied more broadly across palaeoecology and biogeography, our results also highlight a number of research challenges that still need to be addressed, including developing sporopollenin-specific taxonomic discriminators and determining a more complete understanding of the effects of environmental variation on pollen-chemical signatures in Quercus.

ecology↗