ORCID Profile
0000-0002-1209-2622
Current Organisation
Universidade de Lisboa
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: CSIRO Publishing
Date: 21-02-2023
DOI: 10.1071/SR22109
Abstract: Context Acacia longifolia is an aggressive invader, disrupting habitats and communities worldwide. Understanding what drives its expansion is of paramount importance. Key functional traits include fast growth and the presence of bacterial symbionts performing nitrogen fixation. Aims To address early plant development of A. longifolia under different soils and growth conditions (water and nutrition availability), establishing the key factors that influence above and belowground responses. Methods Plants were grown in pots with soils collected from forest, agricultural and dune areas in relative proximity, in a controlled experiment designed to study water effect and nutrient availability on early growth. Growth parameters included shoot and root length, nodule number and weight. Bacteria were isolated from nodules for genetic ersity evaluation. Photosynthetic pigments and isotopic nitrogen and carbon analyses were performed to address nitrogen fixation and photosynthesis. Key results Soil origin influenced plant growth and bacterial ersity. Largest plant development was achieved in forest soils with added nutrition and water. Plants from agricultural soil displayed higher aboveground development however, belowground nodule number and bacterial bio ersity decreased, possibly due to anthropogenic activities. Forest soil promoted belowground development and bacterial ersity. In dune soils overall growth was lower and nitrogen fixation was higher. Conclusion Abiotic factors influenced juvenile acacia development nutrition acts as a growth enhancer, and soil origin, including its microbial communities, can be considered a development modulator. Bacterial ersity varied according to soil type. Implications Several above and belowground interactions showed the need for an integrative perspective to understand acacias invasive potential.
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.PHYTOCHEM.2019.112126
Abstract: Thyme (Thymus spp.) is a valuable genus of Lamiaceae family with different pharmaceutical and food properties. Thymol has also been considered as the major essential oil compound in most of the studied Thymus species. In this research, the gene encoding γ-terpinene synthase (Ttps2) was sequenced in T. vulgaris and in eight Iranian thymes including T. carmanicus, T. daenensis, T. fedtschenkoi, T. kotschyanus, T. migricus, T. pubescens, T. serpyllum, and T. trautvetteri. Genetic relationships based on terpene synthase genes were also determined among the studied species. Rapid Amplification of cDNA Ends (RACE) PCR was done to complete the sequence of all species. The cDNA of the studied species possessed an open reading frame ranging from 1788 to 1794 bp that encode for a protein of 596-598 amino acids, presenting all the conserved motifs characteristics of monoterpene synthases. The taxonomic status of Thymus species was determined based on eight reported sections. The species were classified in three major groups. The first and second group comprised species of Micantes and Mastichina sections. The third cluster included the species belonging to Serpyllum and Pseudothymbra sections. Overall, phylogenetic analysis according to whole sequence of Ttps2 gene can help providing insights in respect to its evolutionary process. Finally, clustering based on the amount of main essential oils components (thymol and carvacrol) was compared with that based on Ttps2 gene classification in the studied Thymus species, showing that clustering is not always in accordance.
Publisher: Oxford University Press (OUP)
Date: 20-04-2021
DOI: 10.1093/AOB/MCAB053
Abstract: Invasive species may undergo rapid evolution despite very limited standing genetic ersity. This so-called genetic paradox of biological invasions assumes that an invasive species has experienced (and survived) a genetic bottleneck and then underwent local adaptation in the new range. In this study, we test how often Australian acacias (genus Acacia), one of the world’s most problematic invasive tree groups, have experienced genetic bottlenecks and inbreeding. We collated genetic data from 51 different genetic studies on Acacia species to compare genetic ersity between native and invasive populations. These studies analysed 37 different Acacia species, with genetic data from the invasive ranges of 11 species, and data from the native range for 36 species (14 of these 36 species are known to be invasive somewhere in the world, and the other 22 are not known to be invasive). Levels of genetic ersity are similar in native and invasive populations, and there is little evidence of invasive populations being extensively inbred. Levels of genetic ersity in native range populations also did not differ significantly between species that have and that do not have invasive populations. We attribute our findings to the impressive movement, introduction effort and human usage of Australian acacias around the world.
Publisher: Pensoft Publishers
Date: 21-02-2023
DOI: 10.3897/NEOBIOTA.82.87455
Abstract: Acacia longifolia (Sydney golden wattle) is considered one of the most problematic plant invaders in Mediterranean-type ecosystems. In this study, we investigate the species’ invasion history by comparing the genetic ersity and structure of native (Australia) and several invasive range (Brazil, Portugal, South Africa, Spain, and Uruguay) populations and by modelling different introduction scenarios using these data. We s led 272 A. longifolia in iduals – 126 from different invasive ranges and 146 from the native range – from 41 populations. We genotyped all in iduals at four chloroplast and 12 nuclear microsatellite markers. From these data we calculated ersity metrics, identified chloroplast haplotypes, and estimated population genetic structure based on Bayesian assignment tests. We used Approximate Bayesian Computation (ABC) models to infer the likely introduction history into each invaded country. In Australia, population genetic structure of A. longifolia appears to be strongly shaped by the Bass Strait and we identified two genetic clusters largely corresponding to mainland Australian and Tasmanian populations. We found invasive populations to represent a mixture of these clusters. Similar levels of genetic ersity were present in native and invasive ranges, indicating that invasive populations did not go through a genetic bottleneck. Bayesian assignment tests and chloroplast haplotype frequencies further suggested a secondary introduction event between South Africa and Portugal. However, ABC analyses could not confidently identify the native source(s) of invasive populations in these two countries, probably due to the known high propagule pressure that accompanied these introductions. ABC analyses identified Tasmania as the likely source of invasive populations in Brazil and Uruguay. A definitive native source for Spanish populations could also not be identified. This study shows that tracing the introduction history of A. longifolia is difficult, most likely because of the complexity associated with the extensive movement of the species around the world. Our findings should be considered when planning management and control efforts, such as biological control, in some invaded regions.
Publisher: CSIRO Publishing
Date: 12-2022
DOI: 10.1071/BT21019
Abstract: Context Acacia longifolia is a native legume of south-eastern Australia and Tasmania and is invasive in many parts of the world. A key feature to its success is the production of a high quantity of flowers every season, resulting in a massive seedbank that remains dormant in the soil for decades. Many studies have been performed on this species’ reproductive biology, but none has focused on flowering in detail. Aims Our main objective was to understand this species’ resource allocation strategy that ensures its successful reproduction in the invasive range. Methods We developed an integrative approach, assessing flowering at different levels, namely, canopy and branch flowering (macro scale), downscaling to in idual flower functional stages and their duration, pollen longevity and stigma receptivity (micro scale). We performed this study in three different locations in sand dunes along the Portuguese coast with different environmental conditions. Key results Canopy flowering shows no difference among sites. Pollen and stigma assessment showed that this species is protogynous, with the stigma being highly receptive long before pollen is released. Once released, pollen lasts roughly 72 h. In idual flowers are relatively short-lived, with a rapid progression from closed flower buds to fully open flowers. Implications Our results indicated that A. longifolia has a resource trade-off strategy of investing in flowers and pollen that are relatively short-lived, which are counterbalanced by their massive quantities.
Publisher: Copernicus GmbH
Date: 24-05-2018
Abstract: Abstract. Acacia longifolia is an aggressive invader worldwide. This species was brought to Portugal by the forestry services and is now found throughout the country with very strong ecological and social impacts. Although several ecological and physiological studies have been carried out, molecular studies in this species are sparse. Particularly, genetic variability evaluation in invasive ranges clearly deserves more attention. The aim of this study was to evaluate the genetic ersity and the genetic differentiation among populations of the alien invasive A. longifolia under different Mediterranean conditions. For that we studied three sandy dune populations along the Portuguese coast: Osso da Baleia (mesomediterranean), Pinheiro da Cruz and Vila Nova de Milfontes (termomediterranean). All s led acacia plants were located underneath a pine forest, with the exception of the latter case study, where we also s led in a ersified habitat conditions associated with the margins of agriculture fields. According to the historical records, it was also possible to compare acacia s les from original plantations and recently invaded areas. We have used two molecular markers – inter-simple sequence repeats (ISSR) and microsatellites (SSR). ISSR analysis showed that A. longifolia populations at all s led locations have similar levels of ersity and a relatively low differentiation (ΦPT=0.135). However, s les tended to cluster according to the regional (macro-scale) collection site. Microsatellites confirmed this low differentiation pattern. Our results indicate that differences in phenology and reproductive success observed during a previous study cannot be accounted for by genetic ersity and differentiation alone. Furthermore, our results taken together with historical information of A. longifolia suggest a single original introduction and a subsequent acclimation process.
Publisher: Regional Euro-Asian Biological Invasions Centre Oy (REABIC)
Date: 2020
Publisher: Informa UK Limited
Date: 24-12-2019
No related grants have been discovered for Helena Trindade.