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Genomic signatures of introgression between commercial and native bumblebees, Bombus terrestris, in Western Iberian Peninsula - implications for conservation and trade regulation

Publication . Seabra, Sofia G.; Silva, Sara E.; Nunes, Vera L.; Sousa, Vitor C.; Martins, Joana; Marabuto, Eduardo; Rodrigues, Ana S.B.; Pina-Martins, Francisco; Laurentino, Telma G.; Rebelo, Maria Teresa; Figueiredo, Elisabete; Paulo, Octávio S.

Human‐mediated introductions of species may have profound impacts on native ecosystems. One potential impact with largely unforeseen consequences is the potential admixture of introduced with autochthonous species through hybridization. Throughout the world, bumblebees have been deliberately introduced for crop pollination with known negative impacts on native pollinators. Given the likely allochthonous origin of commercial bumblebees used in Portugal (subspecies Bombus terrestris terrestris and B. t. dalmatinus), our aim was to assess their putative introgression with the native Iberian subspecies B. terrestris lusitanicus. We analysed one mitochondrial gene, cytochrome c oxidase subunit I (COX1) and genomic data involving thousands of genome‐wide restriction‐site‐associated DNA markers (RAD‐seq). In the mitochondrial COX1 analyses, we detected one relatively common haplotype in commercial bumblebees, also present in wild samples collected nearby the greenhouses where the commercial hives are used. In the RAD‐seq analysis, we found a clear genetic differentiation between native and commercial lineages. Furthermore, we detected candidate hybrids in the wild, as well as putatively escaped commercial bumblebees, some of which being potentially fertile males. Although we cannot assess directly the fitness effects of introgressed alleles, there is a risk of maladaptive allele introgression to the local bumblebee subspecies, which can negatively impact autochthon populations. One immediate recommendation to farmers is for the proper disposal of hive boxes, after their use in greenhouses, so as to minimize the risk of escapees contaminating native populations. On the other hand, the feasibility of using local subspecies B. t. lusitanicus, preferably with local production, should be evaluated

2018Journal article

Open access

Utilização de indicadores de atividade microbiana na avaliação da remediação de solos degradados por atividades mineiras – Caso de estudo da utilização de cinzas de biomassa e lamas biológicas da indústria da pasta de papel

Publication . Semedo, Neusa Maria Rodrigues; Mota, Mariana Gomes; Alvarenga, Paula

Este trabalho visou analisar a utilização de indicadores de atividade microbiana na avaliação de ações de remediação de solos afetados por atividades mineiras (Faixa Piritosa Ibérica, FPI), recorrendo a resíduos da indústria da pasta e papel. O estudo foi realizado no âmbito do Projeto Life No_Waste, num Ensaio de Campo em São Domingos, utilizando solos de três minas da FPI (Aljustrel, Lousal e São Domingos) e diferentes corretivos: (i) grânulos de cinzas volantes da combustão de biomassa (GC), (ii) GC e lamas biológicas, do tratamento das águas residuais, compostadas (GC+LC), e (iii) uma mistura de cinzas e lamas tal e qual, sem estabilização prévia (C+L). Os solos originais foram utilizados como controlo. Os resultados mostraram uma melhoria nas características dos solos por aplicação dos materiais: aumento do pH, do teor de matéria orgânica, do teor em azoto Kjeldahl, P e K extraíveis, sem aumento significativo da condutividade elétrica, sendo que os melhores resultados foram obtidos por aplicação de GC+CL ou de C+L. A atividade microbiana nestes solos foi também avaliada recorrendo à quantificação preliminar das comunidades de bactérias e fungos, as quais foram determinadas através de técnica de plaqueamento em meios de culturas específicos. Fez-se também a extração do DNA destes microrganismos, de modo a amplificar os extratos de DNA, utilizando a técnica de PCR com primers específicos de cada grupo de organismos. Através do método de plaqueamento, observou-se uma maior carga de fungos do que de bactérias nos solos originais, tendência que se inverteu com a aplicação dos corretivos, com um aumento significativo do número de bactérias nos solos tratados com cinzas e lamas, estabilizadas e não estabilizadas. Foram testados três métodos de extração de DNA, tendo-se mostrado como mais eficiente para este tipo de amostras, solo poluído com alto teor de ácido húmico, o método de Kit DNeasy®PowerSoil®

2020Master thesis

Open access

Olive anthracnose: a yield- and oil quality-degrading disease caused by several species of Colletotrichum that differ in virulence, host preference and geographical distribution

Publication . Talhinhas, Pedro; Loureiro, Andreia; Oliveira, Helena

Olive anthracnose causes fruit rot leading to its drop or mummification, resulting in yield losses and the degradation of oil quality. Taxonomy and distribution: The disease is caused by diverse species of Colletotrichum, mostly clustering in the C. acutatum species complex. Colletotrichum nymphaeae and C. godetiae are the prevalent species in the Northern Hemisphere, whereas C. acutatum sensu stricto is the most frequent species in the Southern Hemisphere, although it is recently and quickly emerging in the Northern Hemisphere. The disease has been reported from all continents, but it attains higher incidence and severity in the west of the Mediterranean Basin, where it is endemic in traditional orchards of susceptible cultivars. Life cycle: The pathogens are able to survive on vegetative organs. On the fruit surface, infections remain quiescent until fruit maturity, when typical anthracnose symptoms develop. Under severe epidemics, defoliation and death of branches can also occur. Pathogen species differ in virulence, although this depends on the cultivar. Control: The selection of resistant cultivars depends strongly on pathogen diversity and environmental conditions, posing added difficulties to breeding efforts. Chemical disease control is normally achieved with copper-based fungicides, although this may be insufficient under highly favourable disease conditions and causes concern because of the presence of fungicide residues in the oil. In areas in which the incidence is high, farmers pathogen interactions is basal for the deployment of durable and effective disease control strategies, whether based on resistance breeding, agronomic practices or biological or chemical control

2018Journal article

Open access

Bioclimatic modeling in the Last Glacial Maximum, Mid-Holocene and facing future climatic changes in the strawberry tree (Arbutus unedo L.)

Publication . Ribeiro, Maria Margarida; Roque, Natália; Ribeiro, Sílvia; Gavinhos, Catarina; Castanheira, Isabel; Quinta-Nova, Luís; Albuquerque, Teresa; Gerassis, Saki

Increasing forest wildfires in Portugal remain a growing concern since forests in the Mediterranean region are vulnerable to recent global warming and reduction of precipitation. Therefore, a long-term negative effect is expected on the vegetation, with increasing drought and areas burnt by fires. The strawberry tree (Arbutus unedo L.) is particularly used in Portugal to produce a spirit by processing its fruits and is the main income for forestry owners. Other applications are possible due to the fruit and leaves’ anti-oxidant properties and bioactive compounds production, with a potential for clinical and food uses. It is a sclerophyllous plant, dry-adapted and fire resistant, enduring the Mediterranean climate, and recently considered as a possibility for afforestation, to intensify forest discontinuity where pines and eucalypts monoculture dominate the region. To improve our knowledge about the species’ spatial distribution we used 318 plots (the centroid of a 1 km2 square grid) measuring the species presence and nine environmental attributes. The seven bioclimatic variables most impacting on the species distribution and two topographic features, slope and altitude, were used. The past, current and future climate data were obtained through WorldClim. Finally, the vulnerability of the strawberry tree to the effects of global climate change was examined in the face of two emission scenarios (RCP 4.5 and 8.5), to predict distribution changes in the years 2050 and 2070, using a species distribution models (MaxEnt). The reduction of suitable habitat for this species is significant in the southern regions, considering the future scenarios of global warming. Central and northern mountainous regions are putative predicted refuges for this species. Forest policy and management should reflect the impact of climate change on the usable areas for forestry, particularly considering species adapted to the Mediterranean regions and wildfires, such as the strawberry tree. The distribution of the species in the Last Glacial Maximum (LGM) and Mid-Holocene (MH) agrees with previous genetic and paleontological studies in the region, which support putative refuges for the species. Two in the southern and coastal-central regions, since the LGM, and one in the eastcentral mountainous region, considered as cryptic refugia

2019-01Journal article

Open access

Desenvolvimento de bolachas com incorporação de diferentes microalgas

Publication . Fragoso, Solange Pereira; Batista, Ana Paula dos Santos; Fradinho, Patrícia

Devido ao seu potencial como fonte de vários compostos bioativos, as microalgas são capazes de aumentar o valor nutricional de alimentos convencionais, afetando positivamente a saúde humana. O objetivo deste estudo foi o desenvolvimento de bolachas doces com incorporação de diferentes concentrações (2% e 6% m/m) de quatro microalgas diferentes: Spirulina platensis F&M-C256, Chlorella vulgaris Allma, Tetraselmis suecica F&M-M33 e Phaeodactylum tricornutum F&M-M40. Foram avaliadas características como a textura, a cor e a atividade da água das bolachas ao longo de oito semanas, não se encontrando diferenças significativas em termos de cor e de textura (p<0,05) nas amostras analisadas. Em relação à atividade da água, todas as bolachas apresentaram valores inferiores a 0,5 após oito semanas de armazenamento. A bolacha com incorporação de 6% de Spirulina foi a que apresentou valores mais elevados de firmeza, em resposta a testes de penetração simples. A caracterização reológica das massas (antes da cozedura) também revelou para esta amostra valores mais elevados de viscosidade e dos módulos viscoelásticos (G’ e G’’). Consequentemente, utilizando 6% de Spirulina, foi possível reduzir o teor de farinha de 49% para 37% (m/m) e manter propriedades viscoelásticas semelhantes aos da massa de bolacha controlo. A avaliação da composição química demonstrou ser o teor proteico o parâmetro em que se verificaram diferenças mais significativas (p<0,05), sendo as bolachas com 6% de Spirulina e de Chlorella as que apresentaram maior teor proteico (7,8-8,0%) comparativamente ao controlo (4,9%). O teor de ficocianina foi de 172 mg/kg e 363 mg/kg para as bolachas com incorporação de 2% e 6% de Spirulina, respetivamente. A análise sensorial revelou que os provadores preferiram as bolachas com incorporação de Spirulina em particular a com 2%.

2016Master thesis

Open access