Pedro Alexander Velasquez-Vasconez

Prof. Dr. Pedro Alexander Velasquez-Vasconez

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Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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PVPedro Alexander Velasquez-Vasconez
Pedro Alexander Velasquez-Vasconez
BHBenjamin Hunt
Benjamin Hunt
RDRenata Dias
Renata Dias
TSThaís P. Souza
Thaís P. Souza
CBChris Bass
Chris Bass
Marcio Silva-FilhoMarcio Silva-Filho
Marcio Silva-Filho
Molecular phenotypes induced by environmental stimuli can be transmitted to offspring through epigenetic inheritance. Using transcriptome profiling, we show that the adaptation of Helicoverpa armigera larvae to soybean peptidase inhibitors (SPIs) is associated with large-scale gene expression changes including the upregulation of genes encoding serine peptidases in the digestive system. Furthermore, approximately 60% of the gene expression changes induced by SPIs persisted in the next generation of larvae fed on SPI-free diets including genes encoding regulatory, oxidoreductase, and protease functions. To investigate the role of epigenetic mechanisms in regulating SPI adaptation, the methylome of the digestive system of first-generation larvae (fed on a diet with and without SPIs) and of the progeny of larvae exposed to SPIs were characterized. A comparative analysis between RNA-seq and Methyl-seq data did not show a direct relationship between differentially methylated and differentially expressed genes, while trypsin and chymotrypsin genes were unmethylated in all treatments. Rather, DNA methylation potential epialleles were associated with transcriptional and translational controls; these may play a regulatory role in the adaptation of H. armigera to SPIs. Altogether, our findings provided insight into the mechanisms of insect adaptation to plant antiherbivore defense proteins and illustrated how large-scale transcriptional reprograming of insect genes can be transmitted across generations.

6 April 2024 in Sustainability
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PVPedro Alexander Velasquez-Vasconez
Pedro Alexander Velasquez-Vasconez
DADanita Andrade-Díaz
Danita Andrade-Díaz
MDMaria Iverh Zambrano Diaz
Maria Iverh Zambrano Diaz
Juan S. Chirivi-SalomonJuan S. Chirivi-Salomon
Juan S. Chirivi-Salomon
Human development must ensure the welfare and survival of an ever-growing population. To assess the impact of agroecosystems on sustainability in Nariño (Colombia), variables related to sustainable development were evaluated through a semi-structured survey conducted with 122 producers from 6 municipalities in the Nariño department. The association between the categorical variables associated with the pillars of sustainability was analyzed using multiple correspondence analysis (MCA). From the MCA, 23 indicators were selected, representing quantitative information on the economic, social, and environmental characteristics of the participants. The municipalities were characterized according to the needs and strengths of the producers. Five groups encompass most characteristics of the producers, which are largely independent of geopolitical conditions. On the other hand, the population characterization indicates that the economic well-being of fruit growers can promote the conservation of natural resources. Finally, a principal component factor analysis (PCFA) was conducted to construct the General Sustainability Index (GSI). A network graph for each municipality revealed that the indicators of the production systems are in an unfavorable environment in almost all aspects related to sustainability. The GSI values reveal unstable agroecological conditions that are causing environmental deterioration, with critical levels in the municipalities of Arboleda, Sandoná, and Providencia. Social investment and public policies must be implemented to improve the economic conditions of the producers, accompanied by legislation on the proper management of natural resources.

18 October 2024 in Horticulturae
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OCOvidio Javier Moran Chamorro
Ovidio Javier Moran Chamorro
DADanita Andrade-Díaz
Danita Andrade-Díaz
Juan S. Chirivi-SalomonJuan S. Chirivi-Salomon
Juan S. Chirivi-Salomon
PVPedro Alexander Velasquez-Vasconez
Pedro Alexander Velasquez-Vasconez
Companion cropping offers a potential solution to the challenges of sustainable agriculture, such as optimizing resource use and reducing reliance on chemical inputs. The problem of achieving higher yields while maintaining environmental health remains critical. This practice enhances natural resource conservation, improves fertilization, and optimizes nutrient cycling through the balanced use of chemical and organic sources. Studies, such as those involving tree tomato and Hass avocado, have demonstrated a significant yield increase compared to monocultures, underscoring the viability of this practice. In addition to their environmental benefits, companion crops provide economic advantages by allowing producers to harvest multiple products simultaneously, thereby strengthening food security and the rural economy. This study evaluated three levels of fertilization and interactions between fruit trees at different altitudes, observing differential behavior in the variables evaluated. The combination of cape gooseberry and blackberry showed significantly positive results, with more leaves and fewer pests, demonstrating the benefits of companion plants. A trend towards the combined use of chemical and organic fertilizers was observed, a potential strategy to reduce costs and improve crop growth. The results indicated that the UF system (P. peruviana and P. vulgaris) had the highest plant height, while TF (tree tomato and bean) showed the best stem perimeter development. The incidence of pests was also significant, with Trialeurodes vaporarioum being most prevalent in the P. peruviana companion. These findings support companion cropping as a viable and promising strategy for more efficient and sustainable agriculture, offering both environmental and economic benefits.

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PVPedro Alexander Velasquez-Vasconez
Pedro Alexander Velasquez-Vasconez
ROReyven Yair Chaves Ordoñez
Reyven Yair Chaves Ordoñez
JPJuan David Pantoja
Juan David Pantoja
TDTharling Yadhannia Hernandez Diaz
Tharling Yadhannia Hernandez Diaz
LMLuz Estela Lagos Mora
Luz Estela Lagos Mora
CSClaudia Salazar-González
Claudia Salazar-González
Phytophthora infestans remains a major threat to global potato production. This study focused on characterizing and assessing the pathogenicity of P. infestans isolates on detached potato leaves and in greenhouse trials across four cultivars. Seven isolates were obtained from high potato-producing regions in the department of Nariño, Colombia. The isolates were analyzed using 12 microsatellite markers to determine genetic distances. Two genetically distinct isolates showed markedly different pathogenicity on detached leaves: isolate P00921 caused complete infection by day five, whereas P00321 showed no symptoms. These two isolates (P00921 and P00321) selected for having the greatest genetic distance and highest pathogenicity among the seven analyzed were further tested in a greenhouse setup on four potato cultivars using a randomized block design. Disease progression was monitored over nine days. The results indicated significant variations in pathogenicity linked to genetic diversity among isolates. Notably, Capiro and Margarita cultivars were more prone to severe disease than Suprema and Única. These findings highlight the complex nature of host–pathogen interactions and suggest the need for tailored approaches in disease management and cultivar selection.

1 January 2026 in Revista de Ciencias Agrícolas
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PVPedro Alexander Velasquez-Vasconez
Pedro Alexander Velasquez-Vasconez
MCMaría Isabel Castro
María Isabel Castro
DCDagoberto Criollo
Dagoberto Criollo
EDEsteban Diaz
Esteban Diaz
JZJuan Carlos Zambrano
Juan Carlos Zambrano
Theobroma grandiflorum (cupuassu) is an Amazonian fruit tree of increasing importance for agro-industrial development in Colombia due to its nutritional value and multiple commercial applications. However, its cultivation still faces limitations due to insufficient knowledge regarding the adaptability and productivity of its genotypes under local conditions. This study aimed to evaluate eight genotypes over a three-year period in an experimental field located in Florencia, Caquetá, Colombia. The trial was established as a monoculture of trees with a repeated-measures design. Data included productive variables (fruit number, weight, pulp, and seed yields) and nutritional composition (minerals, fatty acids, and bromatological parameters). The analysis of variance (ANOVA) and Duncan's test revealed significant differences (p < 0.05) among the genotypes, with UNR146 and UNR153 excelling in pulp yield (29.00 kg and 29.97 kg, respectively) and almond yield (12.92 kg and 14.81 kg, respectively). These two genotypes showed a superior number of fruits per tree (65 and 71, respectively), positively influencing total almond and pulp production. Furthermore, UNR146 and UNR153 demonstrated consistent performance across three consecutive years of evaluation, outperforming other genotypes, particularly in almond and pulp yield. Their high productivity is coupled with favorable mineral and fatty acid profiles, with UNR153 achieving the highest almond yield at 14.8 kg per plant. Principal component analysis revealed key relationships between minerals and fatty acids, highlighting differences in pulp and seed quality. Clones UNR146 and UNR153 exhibit strong genetic potential to improve cupuassu yield and quality under tropical conditions in the Colombian Amazon.

13 July 2026 in BioTech
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BPBairon J. Matabanchoy Pejendino
Bairon J. Matabanchoy Pejendino
EMEduardo Vicente Mallama
Eduardo Vicente Mallama
MRMaría C. Díaz Rodríguez
María C. Díaz Rodríguez
CSClaudia Salazar-González
Claudia Salazar-González
PVPedro Alexander Velasquez-Vasconez
Pedro Alexander Velasquez-Vasconez
Helicoverpa armigera is one of the most destructive polyphagous pests, yet the transcriptional organization underlying its digestive capacity remains poorly resolved. Here, we compiled 579 publicly available RNA-seq libraries representing 54 independent experiments and quantified transcript abundance across tissues and developmental stages. This complete dataset was used to support broader tissue-level expression profiling. After metadata harmonization and quality filtering, a subset of 130 biologically comparable libraries from five tissue/developmental categories was retained for weighted gene co-expression network analysis. WGCNA identified four biologically informative modules, among which the turquoise module was positively associated with fourth- and fifth-instar larval midgut samples. Independent expression profiling revealed strong midgut-biased expression of several trypsin- and chymotrypsin-like serine proteases, although only a subset of these genes was assigned to the turquoise module. Descriptive functional annotation of this module identified 202 co-expressed loci, including digestive enzymes, nutrient transporters, detoxification-related proteins, epithelial components and putative transcriptional or signaling-associated genes. Phylogenetic analyses and manual inspection of genomic locations further showed that several digestive protease genes occur in local clusters and have closely related counterparts in H. zea, suggesting partial conservation of local genomic organization. Collectively, these results describe a midgut-associated co-expression module containing genes associated with digestive, absorptive and protective functions and provide candidate genes for future functional studies.