Percorrer por autor "Ragonezi, Carla"
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- Adventitious rooting of conifers: influence of biological factorsPublication . Zavattieri, Maria Amely; Ragonezi, Carla; Klimaszewska, KrystynaVegetative propagation of superior conifer trees can be achieved, e.g., through rooted cuttings or rooted microshoots, the latter predominantly through in vitro tis sue culture. Both techniques are used to achieve rapid multiplication of trees with favorable genetic combinations and to capture a large proportion of the genetic diversity in a single generation cycle. However, adventitious rooting of shoots (cuttings) is often not efficient due to various problems, such as scarcity of roots and cessation of their growth, both of which limit the application of vegetative propagation in some conifer species. Many factors are involved in the adventitious rooting of shoots, including physical and chemical ones, such as plant growth regula tors, carbohydrates, light quality, temperature and rooting substrates, or media [reviewed by Ragonezi et al. (Trees 24(6):975–992, 2010)]. The focus of this review is on biological factors, such as inoculations with Agrobacterium rhizogenes, plant-growth promoting rhizobacteria and other endophytes, and mycorrhizal fungi, which were found to stimulate adventitious rooting. These microor ganisms could contribute not only to adventitious root development but also to help in protecting conifer plants against pathogenic microorganisms, facilitate acclimation and transplanting, and contribute to more sustainable, chemical-free forests.
- Alternative oxidase gene family in Hypericum perforatum L.: characterization and expression at the post-germinative phasePublication . Velada, Isabel; Cardoso, Hélia G.; Ragonezi, Carla; Nogales, Amaia; Ferreira, Alexandre; Valadas, Vera; Arnholdt-Schmitt, BirgitAlternative oxidase (AOX) protein is located in the inner mitochondrial membrane and is encoded in the nuclear genome being involved in plant response upon a diversity of environmental stresses and also in normal plant growth and development. Here we report the characterization of the AOX gene family of Hypericum perforatum L. Two AOX genes were identified, both with a structure of four exons (HpAOX1, acc. KU674355 and HpAOX2, acc. KU674356). High variability was found at the N-terminal region of the protein coincident with the high variability identified at the mitochondrial transit peptide. In silico analysis of regulatory elements located at intronic regions identified putative sequences coding for miRNA precursors and trace elements of a transposon. Simple sequence repeats were also identified. Additionally, the mRNA levels for the HpAOX1 and HpAOX2, along with the ones for the HpGAPA (glyceraldehyde-3-phosphate dehydrogenase A subunit) and the HpCAT1 (catalase 1), were evaluated during the post-germinative development. Gene expression analysis was performed by RT-qPCR with accurate data normalization, pointing out HpHYP1 (chamba phenolic oxidative coupling protein 1) and HpH2A (histone 2A) as the most suitable reference genes (RGs) according to GeNorm algorithm. The HpAOX2 transcript demonstrated larger stability during the process with a slight down-regulation in its expression. Contrarily, HpAOX1 and HpGAPA (the corresponding protein is homolog to the chloroplast isoform involved in the photosynthetic carbon assimilation in other plant species) transcripts showed a marked increase, with a similar expression pattern between them, during the post-germinative development. On the other hand, the HpCAT1 (the corresponding protein is homolog to the major H2O2-scavenging enzyme in other plant species) transcripts showed an opposite behavior with a down-regulation during the process. In summary, our findings, although preliminary, highlight the importance to investigate in more detail the participation of AOX genes during the post-germinative development in H. perforatum, in order to explore their functional role in optimizing photosynthesis and in the control of reactive oxygen species (ROS) levels during the process.
- Anticipating the climate change impacts on Madeira’s agriculture: the characterization and monitoring of a vine agrosystemPublication . Carvalho, Miguel Â. A. Pinheiro de; Ragonezi, Carla; Oliveira, Maria Cristina O.; Reis, Fábio; Macedo, Fabrício Lopes; Freitas, José G. R. de; Nóbrega, Humberto; Ganança, José Filipe T.Climate—Madeira Strategy (CMS) foresees two models to describe the climate scenarios for the Madeira region in 2050 and 2070. These scenarios anticipate an average temperature rise of 1.4 to 3.7 ◦C and a decrease in precipitation by 30 to 40%. Consequently, Madeira’s agriculture will suffer the impacts of climate change. To understand these impacts, a baseline of major agrosystem components needs to be established, with the ultimate goal to monitor its consequences in its functioning. CASBio project used the 1961–1991 and 2010–2020 meteorological data series to modulate climate conditions and characterize and monitor six agrosystems for 2 years. One of them was a vineyard, Quinta das Vinhas, representing a typical agrosystem in the Mediterranean climate. The annual and seasonal variation in climatic parameters, soil conditions, microbiological communities, floristic and insect diversity, and crop production was assessed, using a total of 50 parameters. The results were used to establish a baseline of the agrosystem components and their seasonal and annual variation. The major findings are: (i) winter and summer extreme events show a trend in temperature and precipitation supporting a fast change in climate; (ii) a critical imbalance between nitrogen fixing and denitrifying bacteria was identified, especially in summer, that could be determined by the rise in temperature and drought; (iii) among floristic diversity, the therophytes and geophytes confirm to be the most suitable indicators for the rise in temperature and reduction in precipitation in the agrosystems; (iv) an imbalance in favor of C. capitata plague was observed, associated with the summer rise in temperature and decrease in precipitation; (v) despite an increase in most of the grape varieties production, the Madeiran wine local varieties were shown to be less stable in productivity under observed climate conditions. The agrosystem baseline is a starting point for long term monitoring and allows for further quantifying the influence of climate change on agrosystem productivity, resilience, and sustainability.
- Can functional hologenomics aid tackling current challenges in plant breeding?Publication . Nogales, Amaia; Nobre, Tânia; Valadas, Vera; Ragonezi, Carla; Döring, Matthias; Polidoros, Alexios; Arnholdt-Schmitt, BirgitMolecular plant breeding usually overlooks the genetic variability that arises from the association of plants with endophytic microorganisms, when looking at agronomic interesting target traits. This source of variability can have crucial effects on the functionality of the organism considered as a whole (the holobiont), and therefore can be selectable in breeding programs. However, seeing the holobiont as a unit for selection and improvement in breeding programs requires novel approaches for genotyping and phenotyping. These should not focus just at the plant level, but also include the associated endophytes and their functional effects on the plant, to make effective desirable trait screenings. The present review in tends to draw attention to a new research field on functional hologenomics that if associated with adequate phenotyping tools could greatly increase the efficiency of breeding programs.
- Contributo para o conhecimento da agrodiversidade no concelho de Santa Cruz, MadeiraPublication . Carvalho, Miguel A. A. Pinheiro de; Ragonezi, Carla; Macedo, Fabrício Lopes de; Antunes, Gonçalo; Freitas, Gregório; Nóbrega, HumbertoO presente trabalho procura analisar as alterações sofridas pela agrodiversidade no território do Santa Cruz. Este concelho localizado na costa sul da Madeira tem 81,5 km2, quatro patamares bioclimáticos e numerosas unidades agroecológicas (UAE). A evolução da agrodiversidade iniciou-se, com o povoamento do Arquipélago, descoberto inabitado em 1418. A agrodiversidade biofísica, específica e intraespecífica aumentou e diversificou-se, devido à construção de agrossistemas, introdução de culturas, sucessão de ciclos agrícolas, adaptação às condições agroecológicas, aparecimento de pragas e doenças e pela ação do homem. Os registos históricos indicam a introdução de um elevado número de culturas, bem como a utilização de 72 espécies agrícolas, no concelho. E, indicam como fundamentais no povoamento e economia as culturas do trigo e as cerealíferas (cevada, centeio), cana-sacarina, vinha e sumagre. Várias outras culturas desempenharam um papel importante na economia do concelho, sendo cultivadas para fins alimentares, comerciais, industriais, culturais ou religiosos. A adaptação destas espécies aos agrossistemas e às condições agroecológicas deu origem a um número indeterminado de variedades locais. Apesar das limitações da documentação disponível, foram encontradas referências a variedades locais cuja cultura remonta há 140 a 500 anos, nomeadamente o Trigo da Serra, castas Malvasia e Tinta Antiga de Gaula, pêra Caniça, Banana da terra, feijão Corno de carneiro e Couve de João Ferino, que podem ser relacionadas com o historial do concelho. Porém, desde meados do século XX, a agrodiversidade sofreu uma drástica redução com a diminuição das áreas cultivadas, o abandono de várias espécies agrícolas e a extinção de variedades locais. A análise desta agrodiversidade foi realizada, a fim de apurar as alterações históricas e geográficas ocorridas na agrodiversidade em onze culturas representativas do concelho, visando a sustentabilidade agronómica.
- Different seaweeds use for iodine deficiency overcomePublication . Ferraz, Sónia; Ragonezi, Carla; Nunes, Nuno; Valente, Sofia; Carvalho, Miguel A. A. Pinheiro deIodine deficiency is one of the three most common nutritional deficiencies worldwide and is a global public health problem that affects particularly the young children, pregnant women and elderly. The consequences of iodine deficiency disorder (IDD) include goiter and cretinism. The traditional consumption of iodine via supplemented salt should be monitored to reduce population sodium intake due to hypertension problems and the uncertain bioavailability of iodine in the supplemented salt. One approach for an effective and cost-efficient iodine supplementation is the use of seaweeds in food intake. Seaweeds, among all foods, are the most famous and reliable source of natural iodine. In this minireview we pretend to explore the different uses of seaweeds to fill the iodine deficiency and improve life quality.
- Distribution of Genetic Diversity in Beta patula Aiton Populations from Madeira Archipelago, PortugalPublication . Ragonezi, Carla; Nóbrega, Humberto; Leite, Maria Inês; Freitas, José G. R. de; Macedo, Fabrício Lopes; Carvalho, Miguel Â. A. Pinheiro deBeta patula Aiton is a crop wild relative (CWR) which belongs to the Gene Pool 1b and is considered a Critically Endangered species, and is present in very specific environments, such as the Desembarcadouro islet (DI) in Ponta de São Lourenço or Chão islet (CI) in the Desertas Islands. The ISOPlexis Center (University of Madeira) has been providing continuous support for its in situ conservation by keeping a management plan of wild populations and an ex situ conservation strategy through the storage of accessions in the ISOPlexis GeneBank. The present work intends to present the spatial distribution of genetic variability and diversity in these B. patula populations using eight polymorphic Simple Sequence Repeat (SSR) markers. The overall results lead to the identification of three spots with a high genetic diversity. CI with a small cluster of individuals shows a genetic footprint different from DI, having unique alleles present in its population. DI has two distinct areas: the western area, with a higher individual density but with a lower genetic diversity and higher allele fixation; and the central area, with a lower individual count but with a higher genetic diversity and with the presence of unique alleles. Despite some genetic differences, the comparison of the two islets’ DI and CI populations shows that they have more similarities than differences. Analysis of the Molecular Variance, based on the hierarchical cluster, showed a 9% diversity between populations, 68% among individuals, and 23% within individuals. This data will be used for the establishment of a protocol to monitor and manage B. patula genetic diversity under a genetic reserve, subsequently contributing to the European Genetic Reserve network implementation and the protection of this important CWR.
- Estimation of Productivity and Above-Ground Biomass for Corn (Zea mays) via Vegetation Indices in Madeira IslandPublication . Macedo, Fabrício Lopes; Nóbrega, Humberto; Freitas, José G. R. de; Ragonezi, Carla; Pinto, Lino; Rosa, Joana; Carvalho, Miguel A. A. PinheiroThe advancement of technology associated with the field, especially the use of unmanned aerial vehicles (UAV) coupled with multispectral cameras, allows us to monitor the condition of crops in real time and contribute to the field of machine learning. The objective of this study was to estimate both productivity and above-ground biomass (AGB) for the corn crop by applying different vegetation indices (VIs) via high-resolution aerial imagery. Among the indices tested, strong correlations were obtained between productivity and the normalized difference vegetation index (NDVI) with a significance level of p < 0.05 (0.719), as well as for the normalized difference red edge (NDRE), or green normalized difference vegetation index (GNDVI) with crop productivity (p < 0.01), respectively 0.809 and 0.859. The AGB results align with those obtained previously; GNDVI and NDRE showed high correlations, but now with a significance level of p < 0.05 (0.758 and 0.695). Both GNDVI and NDRE indices showed coefficients of determination for productivity and AGB estimation with 0.738 and 0.654, and 0.701 and 0.632, respectively. The use of the GNDVI and NDRE indices shows excellent results for estimating productivity as well as AGB for the corn crop, both at the spatial and numerical levels. The possibility of predicting crop productivity is an essential tool for producers, since it allows them to make timely decisions to correct any deficit present in their agricultural plots, and further contributes to AI integration for drone digital optimization.
- Growth and nutrition of eucalypt rooted cuttings promoted by ectomycorrhizal fungi in commercial nurseriesPublication . Gandini, Andrezza Mara Martins; Grazziotti, Paulo Henrique; Rossi, Márcio José; Grazziotti, Danielle Cristina Fonseca Santos; Gandini, Elizzandra Marta Martins; Silva, Enilson de Barros; Ragonezi, CarlaEctomycorrhizal fungi (EMF) may improve the adaptation of eucalypts saplings to field conditions and allow more efficient fertilizer use. The effectiveness of EMF inoculum application in promoting fungal colonization, plant growth, nutrient uptake, and the quality of rooted cuttings was evaluated for Eucalyptus urophylla under commercial nursery conditions. For inoculated treatments, fertilization of the sapling substrate was reduced by 50 %. The experiment was carried out in a completely randomized design in a 4 × 4 factorial arrangement, wherein the factors were inoculum application rates of 0 (control), 5, 10, and 15 gel beads of calcium alginate containing the vegetative mycelium of Amanita muscaria, Elaphomyces antracinus, Pisolithus microcarpus, and Scleroderma areolatum, plus a non-inoculated treatment without fertilization reduction in the substrate (commercial). Ectomycorrhizal fungi increased plant growth and fungal colonization as well as N and K uptake evenly. The best plant growth and fungal colonization were observed for the highest application rate. The greatest growth and fungal colonization and contents of P, N, and K were observed at the 10-bead rate. Plant inoculation with Amanita muscaria, Elaphomyces anthracinus, and Scleroderma areolatum increased P concentrations and contents in a differential manner. The Dickson Quality Index was not affected by the type of fungi or by inoculum application rates. Eucalypt rooted cuttings inoculated with ectomycorrhizal fungi and under half the amount of commercial fertilization had P, N, and K concentrations and contents greater than or equal to those of commercial plants and have high enough quality to be transplanted after 90 days.
- Histological studies of mycorrhized roots and mycorrhizal-like-structures in pine rootsPublication . Ragonezi, Carla; Zavattieri, MariaSeveral studies have shown the potential of using Ectomycorrhizal (ECM) fungi in conifer micropropagation to overcome the cessation of adventitious root development. In vitro inoculation promotes the re-growth of the root system induced previously by auxin treatments, facilitating acclimation and diminishing the losses of plants because of a weak root system that is incapable of water and nutrient absorption. During a series of mycorrhization experiments, cryostat and ultrafine cuts were used to study the morpho-histological transformation of the symbiotic roots. To obtain cryostat cuts from pine roots a method frequently used for animal tissue was adopted. Molecular methods allowed fungi identification in all the mycorrhization phases and in the acclimation of derived plants. Mycorrhizal-like-structures derived from in vitro culture and axenic liquid cultures of roots were microscopically analyzed and compare with mycorrhizal roots.
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