https://hdl.handle.net/10259/9301 2026-04-17T17:33:51Z https://hdl.handle.net/10259/9806 Genetic stability, amino acid, and polyamine profile analyses in radiata pine somatic embryos maturated at high temperatures Montalbán, Itziar Aurora; Castander-Olarieta, Ander; Nascimento, Antonia Maiara Marques do; Suárez Álvarez, Sonia; Polesi, Luiza Giacomolli; Back, Franklin Panato; Steiner, Neusa; Guerra, Miguel Pedro; Moncaleán, Paloma Applying stress factors such as high temperatures during the different stages of somatic embryogenesis is important to uncover the molecular mechanisms of stress response and adaptation, and as a strategy to produce plants adapted to harsh environmental conditions derived from climate changes. In this sense, the present work aims to study the effect of high temperatures applied during the maturation of somatic embryogenesis in the ploidy stability, the amino acid and polyamine profiles of the somatic embryos obtained, and the morphological characteristics of the somatic plantlets. The results revealed that the maturation temperature did not affect the morphology of the resulting somatic plantlets, nor the ploidy and genome size of phenotypically normal somatic embryos, whose ploidy and DNA content levels were similar to those found in mature zygotic embryos. Nonetheless, a slight but significant reduction of the genome size of aberrant somatic embryos was observed. The maturation temperature changed the levels of glycine, arginine, lysine, and ornithine. These last three amino acids are precursors of the polyamines detected. Regarding this, putrescine levels were higher in somatic embryos from the highest maturation temperature (5 min pulse at 60 ºC), however, the amount of this polyamine in all samples was much lower than spermidine, spermine and cadaverine. In conclusion, the different temperatures applied did not lead to substantial changes in the ploidy level, endogenous PAs of the somatic embryos developed, or in the morphology of the somatic plantlets. Significant changes in the endogenous amino acids were observed, which may be linked to PAs metabolism and other metabolic pathways involved in stress response. 2024-03-01T00:00:00Z https://hdl.handle.net/10259/9789 Pinus spp. Somatic Embryo Conversion under High Temperature: Effect on the Morphological and Physiological Characteristics of Plantlets Nascimento, Antonia Maiara Marques do; Barroso, Priscila Alves; Nascimento, Naysa Flavia Ferreira do; Goicoa, Tomás; Ugarte, María Dolores; Montalbán, Itziar Aurora; Moncaleán, Paloma Climatic variations in the current environmental scenario require plants with tolerance to sudden changes in temperature and a decrease in water availability. Accordingly, this tolerance will enable successful plantations and the maintenance of natural and planted forests. Consequently, in the last two decades, drought tolerance and high temperatures in conifers have been an important target for morphological, physiological, and epigenetic studies. Based on this, our research team has optimized different stages of somatic embryogenesis (SE) in Pinus spp. improving the success of the process. Through this method, we can obtain a large amount of clonal material and then analyze the somatic plants under different conditions ex vitro. The analysis of the morphological and physiological parameters in somatic embryos (ses) and plants with different tolerances to abiotic stress can provide us with valuable information about the mechanisms used by plants to survive under adverse environmental conditions. Thus, the objective of this work was to evaluate the influence of high temperatures (23, 40, 50, and 60 °C, after 12 weeks, 90, 30, 5 min, respectively) on the morphology of somatic embryos obtained from Pinus radiata D.Don (Radiata pine) and Pinus halepensis Mill. (Aleppo pine). In addition, we carried out a physiological evaluation of the somatic plants of P. radiata submitted to heat and water stress in a greenhouse. We observed that the number of somatic embryos was not affected by maturation temperatures in both species. Likewise, P. radiata plants obtained from these somatic embryos survived drought and heat stress in the greenhouse. In addition, plants originating from embryonal masses (EMs) subjected to high maturation temperature (40 and 60 °C) had a significant increase in gs and E. Therefore, it is possible to modulate the characteristics of somatic plants produced by the manipulation of environmental conditions during the process of SE. 2020-11-01T00:00:00Z https://hdl.handle.net/10259/9788 The Chemical Environment at Maturation Stage in Pinus spp. Somatic Embryogenesis: Implications in the Polyamine Profile of Somatic Embryos and Morphological Characteristics of the Developed Plantlets Nascimento, Antonia Maiara Marques do; Polesi, Luiza Giacomolli; Back, Franklin Panato; Steiner, Neusa; Guerra, Miguel Pedro; Castander-Olarieta, Ander; Moncaleán, Paloma; Montalbán, Itziar Aurora Changes in the chemical environment at the maturation stage in Pinus spp. somatic embryogenesis will be a determinant factor in the conversion of somatic embryos to plantlets. Furthermore, the study of biochemical and morphological aspects of the somatic embryos could enable the improvement of somatic embryogenesis in Pinus spp. In the present work, the influence of different amino acid combinations, carbohydrate sources, and concentrations at the maturation stage of Pinus radiata D. Don and Pinus halepensis Mill. was analyzed. In P. radiata, the maturation medium supplemented with 175 mM of sucrose and an increase in the amino acid mixture (1,100 mgL–1 of L-glutamine, 1,050 mgL–1 of L-asparagine, 350 mgL–1 of L-arginine, and 35 mgL–1 of L-proline) promoted bigger embryos, with a larger stem diameter and an increase in the number of roots in the germinated somatic embryos, improving the acclimatization success of this species. In P. halepensis, the maturation medium supplemented with 175 mM of maltose improved the germination of somatic embryos. The increase in the amount of amino acids in the maturation medium increased the levels of putrescine in the germinated somatic embryos of P. halepensis. We detected significant differences in the amounts of polyamines between somatic plantlets of P. radiata and P. halepensis; putrescine was less abundant in both species. For the first time, in P. radiata and P. halepensis somatic embryogenesis, we detected the presence of cadaverine, and its concentration changed according to the species. 2021-11-01T00:00:00Z https://hdl.handle.net/10259/9787 A Computer Vision‐Based Methodology to Estimate Fruit Colour Diversity in Ornamental Pepper (Capsicum spp.) Santos, Marcos Bruno da Costa; Melo, Raylson de Sá; Sousa, Victor Eduardo de Carvalho; Medeiros, Artur Mendes; Pessoa, Angela M. dos S.; Silva, Silvokleio da Costa; Nascimento, Antonia Maiara Marques do; Barroso, Priscila Alves Fruit colour diversity within different ripening stages confers ornamental value for pepper plants. Using images can be helpful in analysing the fruit colour-related genetic diversity and enable selecting accessions for ornamental purposes by avoiding subjectiveness. This study aimed to evaluate the phenotypic diversity among accessions of ornamental pepper using image processing techniques to identify fruit colours. Photos from 40 fruits from each of 12 accessions were captured by a camera from a smartphone. Separate channels and colour indices were extracted from the images to analyse the accessions using both dendrogram and principal components analysis. Dendrogram analysis allowed separating accessions with predominance of dark fruits from those whose fruits showed lighter and more vivid colours, with a cophenetic correlation coefficient of 0.811. The VARI and NGRDI vegetation indices were efficient in discriminating fruits with a predominance of green colour, and the BGI could be used to discriminate accessions with predominantly reddish-brown fruits. The proposed method can be used in small-scale breeding programs for accurately assessing the development of varieties regarding their fruit colour diversity. 2024-11-01T00:00:00Z