Agronomía Mesoamericana journal is a continuous publication with an annual open issue that begins in January and closes in December. Edited in the Universidad de Costa Rica, its objective is to disseminate original scientific information in Spanish or English language, through the publication of articles, short communications, technical notes and literature reviews, related with food and agriculture sciences from anywhere in the world, emphasized in tropical and subtropical zones. Agronomía Mesoamericana implements interoperability protocols that allow the journal to be harvested by other content distribution systems. It supports this process through the OAI-PMH protocol (Open Archives Initiative Protocol for Metadata Harvesting) that allows the transfer of scientific and open access digital resources. URL OAI-PMH https://revistas.ucr.ac.cr/index.php/agromeso/oai
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Allelopathy of Ageratum conyzoides L. on Bidens pilosa L., Oryza sativa L. and Cucumis sativus L.
Introduction. Ageratum conyzoides is considered an invasive species; nevertheless, its allelopathic potential has been identified. Allelopathic extracts offer a potential alternative to conventional weed control. Objective.Determine the allelopathic effect of extracts of A. conyzoides L. on seedling emergence and initial growth of the weed Bidens pilosa L. and the crops Cucumis sativus L. and Oryza sativa L.. Materials and methods. From January to October 2021, in the greenhouse of the Fraijanes Substation, Alajuela, Costa Rica, fresh and dried extracts prepared from A. conyzoides leaves were tested. Each extract was prepared at concentrations of 100 %, 50 %, and 25 % (w/v), and applied to seeds of selected weeds and crops. The number of emerged seedlings, radicle length, shoot and seedling length, as well as biomass of weeds and crops, were determined; a completely randomized design was used. Data were analyzed using analysis of variance and Tukey’s test (for seedling and root length, and biomass) and logistic regression (for emerged seedlings). Results. The allelopathic extracts of A. conyzoides inhibited the emergence of B. pilosa seedlings; the 50% dose was more inhibitory than the 100% dose (odds ratio = 3.12) and resulted in shorter root lengthlength and lower biomass. In O. sativa, the use of both extracts showed no inhibitory effect on germination compared with the control; however, the fresh extract resulted in shorter plant length. Neither extract affected C. sativus. Conclusion. A. conyzoides extract showed inhibitory effects on B. pilosa and O. sativa but did not affect C. sativus.
Copyright (c) 2026 Alicia Zumbado-Rodríguez, Mary Pamela Portuguez-García, María Isabel González-Lutz (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Agronomic characteristics of maralfalfa (Pennisetum sp.) seedlings according to sowing and harvesting density
Introduction. Maralfalfa (Pennisetum sp.) stands out for its forage productivity in tropical regions; however, technical evidence regarding its management for propagule production is insufficient. The quality of asexual seed is subject to agronomic factors that determine stem robustness and physiological maturity. Objective. To evaluate the effect of planting density and the number of harvests on the yield and morphometric characteristics of maralfalfa as a seed nursery. Materials and methods. The study was conducted in Huaral, Peru (2018-2019), using a completely randomized design with a 3 × 2 factorial arrangement. Three planting densities (0.50, 0.75, and 1.00 m between plants; 0.80 m between rows) and two harvests (120 days post-planting and 90 days post-cut) were evaluated. Fresh biomass yield (FBY), plant height (PH), stem weight (SW), number of tillers per plant (NTP), stem diameter (SD), and number of stem nodes (NSN) were quantified. Results. No significant interaction between factors was detected (p > 0.05). FBY, SW, and NTP were significantly higher (p < 0.05) in the second harvest, with increases of 45 % (1.45 vs. 1.00 kg/plant), 29 % (564.31 vs. 437.30 g), and 10 % (3.79 vs. 3.45 tillers), respectively. The largest SD was obtained with a density of 1.00 m (3.97 cm; p < 0.05), while a density of 0.50 m produced plants with higher PH (3.80 m; p < 0.05) and NSN (15 nodes; p < 0.05). Conclusions. The second harvest optimizes yield and tillering due to the consolidation of the root system. For propagule production, a density of 1.00 m favors robustness (diameter), whereas a density of 0.50 m maximizes the availability of nodes per unit area, allowing for differentiated management according to the nursery’s objective.
Copyright (c) 2026 Felix Esteban Airahuacho Bautista, Renzo Arturo Paredes Villarreal , Yaneline Nilda Hidalgo-Vasquez , Oscar Enrique Arbañil Huaman, Rufino Maximo Maguiña-Maza (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Identification of halotolerant bacteria isolated from soils of the Ciénaga de Zapata, Cuba
Introduction. Halotolerant bacteria improve plant adaptability to high salt concentrations in soils, making it essential to study isolates inhabiting vulnerable agroecosystems. Objective. To identify halotolerant bacteria isolated from soils of the Ciénaga de Zapata, Cuba, and to characterize them as plant growthÐpromoting bacteria in plants tolerant to high salinity levels. Materials and methods. The research was conducted in the laboratories of the Instituto de Investigaciones Fundamentales en Agricultura Tropical Alejandro de Humboldt, Cuba, and the Centro Nacional de Recursos Genéticos, Mexico. Five isolates capable of tolerating 200 mM NaCl were selected and phylogenetically identified through 16S rRNA gene sequencing. Laboratory experiments were performed under a completely randomized design, with the five isolates as treatments. Nitrogen fixation, phosphate solubilization, and the production of ammonium, siderophores, indolic compounds, and lytic enzymes were evaluated as response variables. Plant assays were conducted between June and November 2023 under a randomized block design with six treatments (five bacterial strains and an uninoculated control), with three replicates, assessing plant growth and salinity tolerance indicators. Data were subjected to one-way analysis of variance and Duncan’s test at 5 % significance. Results. The isolates belonged to the genera Bacillus and Cupriavidus. All fixed atmospheric nitrogen and solubilized calcium phosphate; four produced siderophores; two generated ammonium; two solubilized potassium; two synthesized indolic compounds and lytic enzymes; and one solubilized aluminum. In plant assays, strains CZ1 and CZ6 stood out, showing significant differences compared to the other strains and the control. Conclusions. The isolated halotolerant bacteria possess traits that support their use as microbial inoculants in saline environments.
Copyright (c) 2026 Marisel Ortega-García, Yoania Ríos-Rocafull, Alfredo Socorro-García, Lily Xochil Zelaya-Molina, Ismael Fernando Chávez-Díaz, Maria Caridad Napoles Garcia (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Fusarium wilt by tropical race 4: Current status and presence in the American continent
Introduction. Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. cubense, tropical race 4, is considered the most lethal disease of the musaceae because it can survive on the ground for more than twenty years, without effective control. Objective. Review the current status and significant features of this disease and indicate the potential impact risk in Latin America and the Caribbean countries in the face of its recent report in Colombia. Developing. It has several races: race 1 attacks clones of the Silk (Musa AAB) and Gros Michel (Musa AAA) subgroups and was responsible for the loss of the world banana market in 1958, dominated by the latter, being replaced by Cavendish clones (Musa AAA). Race 2 attacks clones of the Bluggoe subgroup (Musa ABB); and race 4, through its tropical and subtropical variants, attacks all Cavendish clones, and those susceptible to race 1 and race 2. There are no natural clones that can replace the current ones. Tropical race 4 (R4T), has spread in different continents, causing multimillion dollar losses, with extreme limitations for its eradication, and recently is a cause for concern in Latin American and Caribbean (LAC) countries, due to its recent report in the Colombian Guajira. Conclusion. The deficient control, and ignorance of thr traits of the pathogen and the disease, make necessary the development of research for its early diagnosis, management strategies, education measures, and / or promotion of contingency plans. Recently it was detected in Colombia, which implies high risk for the rest of the countries of the LAC region (with emphasis on Ecuador, Panama, and Venezuela), due to the constant flow of people (including tourists) and commercial transactions, being necessary in a way it is imperative to review the risk analysis in this new scenario.
Copyright (c) 2020 Gustavo E. Martínez-Solórzano, Juan C. Rey-Brina, Rafael E. Pargas-Pichardo, Edwuar Enrique-Manzanilla (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Purines discharge capacity of a liquid manure spreading tank
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Liquid manure can improve soil structure and crop productivity, but calibrated equipment is needed to achieve uniform distribution. Objective. The objective of this work was to determine at the field level, the appropriate combinations of operation of a liquid manure distribution tank and a tractor that commands it to achieve a uniform distribution of slurry and diluted manure. Materials and methods. The experiment was carried out during July 2016 at the Experimental Station “Alfredo Volio Mata” of the Universidad de Costa Rica, in Ochomogo of Cartago, Costa Rica. A plowed and harrowed plot of 5000 m2 was used where twenty plastic containers were placed, arranged in two rows separated, 4 m between and within rows. A manure tank coupled to a tractor was used and the treatments were four travel speeds (four low gears of the tractor) and a fixed degree of acceleration (442 rpm). The measured variables were the capacity and volume of discharge per unit area, and the covered area. Results. The discharge and dispersion of liquid manure in the different gears was highly significant (p<0.01), being the discharge per unit of area greater in the low gears. The relative discharge between the different working speeds was quantified, and the highest discharge gear (Gear I) equivalent to 52 m3 ha-1, was set as 100 %, in gear II the relative discharge was 65 % compared to the first. In gears III and IV, the volumes were 24 and 17 m3 ha-1 respectively. Conclusion. The low gears distributed more material per m2 favorable in more demanding crops, while with higher marches more area can be covered with less material.
Copyright (c) 2020 Carlos Boschini-Figueroa, Claudio Fabián Vargas-Rodríguez (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Owner perceptions and management of stereotypic behaviors in four horse breeds in Costa Rica
Introduction. There is little information about stereotypic behaviors in stock-type sport horses and paso horses in Costa Rica. The lack of knowledge regarding stereotypic behaviors, such as cribbing, weaving, and stall walking in horses, affects their welfare. Objective. The objective of this study was to monitor the status of stereotypic behaviors and the management reported by owners of horses registered in ACRICAMDE and ASCACOPA in Costa Rica.Materials and methods. A cross-sectional survey was conducted from June through September 2018 in Costa Rica to gather information on horse behavior and current management practices of 552 horses of the breeds Quarter Mille, Appaloosa, American Paint Horses and Costa Rica Paso. The database collected was analyzed using descriptive statistics. Results. Almost half of the horse owners (48.4 %) reported stereotypic behaviors, being cribbing the most observed (86.2 %), followed by stall walking (24.1 %) and weaving (13.8 %). Most owners and managers (89.7 %) have tried to stop horses from performing stereotypic behaviors with anti-cribbing collars and by increasing social contact with other horses as the most common approaches. Fewer hours of grazing were reported (2 or less, or none) while there were horses without access to pasture (35.7 %). Conclusion. Horse owners of the breeds included in this study lacked knowledge of stereotypic behaviors. In order to improve management of these behaviors, more training is required to avoid further complexities under the current conditions.
Copyright (c) 2020 Ana Margarita Arias-Esquivel, Carissa L. Wickens, Luis A. Villalobos-Villalobos (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Detection of viruses in sweet potato (Ipomoea batatas L.) using qPCR
Introduction. Sweet potato (Ipomoea batatas) is a root crop very susceptible to viral diseases, which have been associated with crop yield reductions of over 50 %. In the Costa Rican sweet potato plantations the presence of feathery mottle virus (SPFMV), chlorotic stunt virus (SPCSV), and leaf curl virus (SPLCV) have been reported, for the development of adequate control programs, early detection and identification is necessary through the use of sensitive and efficient techniques. Objective. The objective of this research was to estimate the incidence of SPFMV, SPCSV, and SPLCV in sweet potato plantations using qPCR. Materials and methods. In 2018 foliar tissue samples were collected from eighty plants showing viral symptoms from twenty-five sweet potato plantations distributed in four provinces in Costa Rica. The detection of the three viruses was performed by qPCR with the use of primers and specific hydrolysis probes. Results. In 92 % of the plantations studied, the presence of virosis was found. The Sweet potato virus disease (SPVD) defined as the combined infection of SPFMV and SPCSV, was the most common viral disease found in all plantations. The plantations located in Sabanilla, El Cacao, and La Guacima were the only ones to present the three viruses studied. The SPLCV virus was only detected in the Limón and Alajuela provinces. Conclusion. It is possible to make an early detection of three of the most frequent sweet potato viruses with the use of qPCR which would contribute to certified seed production programs.
Copyright (c) 2020 Ingrid Varela-Benavides, Carla Trejos-Araya (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Detection of the 35S promoter by real-time PCR as a transgenicity indicator in food and Gossypium sp.
Introduction. Genetically modified crops (GMC) are of particular interest due to their impact on the global economy. Therefore, as a general concern, many countries have established some regulations in regards to genetically modified organisms (GMOs). In Costa Rica, the cultivation of GMOs has been practiced since 1991; however, there´s a lack of studies that monitor the execution and compliance with the biosafety regulations. Objective. The objective of the present study was to identify the presence or absence of transgenicity in processed foods for human and animal consumption, as well as in cotton seeds. Material and methods. The real-time PCR technique was used to target the 35S promoter sequence, derived from the cauliflower mosaic virus (CaMV), as a marker to detect the presence of transgenes in processed foods for human and animal consumption as well as in wild or cultivated cotton seeds collected nearby a GM cotton farm in May 2017. Results. In the analyzed samples there was a high incidence of an 82 bp fragment, corresponding to the 35S promoter sequence, being absent only in organic corn crops and their derivatives (tortillas, corn powder). Results suggest the presence of GMO traces in the Costa Rican food market, additionally it reveals the urgency of implementing adequate labeling for food traceability. Furthermore, the presence of transgenic cotton in the vicinity of a GM cotton farm was identified, suggesting the relevance of surveillance in aspects of biosafety and genetic manipulation of crops. Conclusion. The presence of traces for GMOs in Costa Rican processed food, demonstrates the importance of continuing this monitoring to provide enough elements for a critic discussion about food traceability and potential transgene flow into wild plant material.
Copyright (c) 2020 Karen Oviedo-Bolaños, Jaime García-González, Stefany Solano-González, Claudio Martínez-Debat, Carolina Sancho-Blanco, Rodolfo Umaña-Castro (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Productive characteristics of forage crops for supplementation in milk production systems, Nariño, Colombia
Introduction. Grass is the main source of feed for ruminants, however, it is not able to provide the nutrients required for its maintenance and productivity, added to this, in the high tropics is very noticeable the seasonality of fodder production, so it is very important to know other feeding alternatives. Objective. Characterize and evaluate ten forage crops as alternative sources of supplementation in milk production systems in the high tropic of Nariño. Materials and methods. The study was carried out in three localities (L1, L2 and L3) representative of the milk basin of the department of Nariño between november 2016 and september 2017. A Random Complete Blocks (BCA) design was used with ten treatments Vicia faba (espadrille), Vicia faba (red), Vicia faba (common), Zea mayz var. ICA V-305, Raphanus sativus L., Beta vulgaris, Avena sativa var. Cayuse, Phalaris sp., Medicago sativa L. var. moapa, Medicago sativa L. var. 10 10, three repetitions and comparison of averages to 0.05. A the time of harvest it was estimated: green forage yield and dry matter, crude protein (PC), neutral detergent fibre (FDN)), acid detergent fibre (FDA), lignin, hemicellulose, dry matter digestibility, and net lactation energy (ENL). Results. The outstanding species were the bean (the three varieties) and fodder beet for its yield and nutritional quality, which presented values between 7.48 and 20.24 % for PC and 1.14 and 1.49 Mcal kg-1 for ENL. Differences between treatments were presented for each locality, both in productive and nutritional variables. Conclusion. The forage species with the highest productive yield and nutritional quality were the three bean varieties (red, common, and espadrille) and beet.
Copyright (c) 2020 David Felipe Nieto-Sierra, Diego Hernán Meneses-Buitrago, Sonia Patricia Morales-Montero, Filadelfo Hernández-Oviedo, Edwin Castro-Rincón (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Production and quality of Tithonia diversifolia and Sambucus nigra high andean colombian tropic
Introduction. Among the limitations of the livestock systems of the Colombian high tropic is fodder seasonality. The use of silvopastoral systems could be a strategy to maximize food production and guarantee a supply of nutrients throughout the year. Objective. To evaluate in Tithonia diversifolia and Sambucus nigra established in a silvopastoral system, the effect of two ages and cutting heights on morphometric, production, and nutritional quality variables. Materials and methods. The study was conducted at the Obonuco Research Center of the Corporacion Colombiana de Investigacion Agropecuaria (AGROSAVIA) (Pasto, Colombia) between January and November 2018. A random block design was established in factorial arrangement with four treatments (two ages and two cutting heights) for each species (T1:60 days*20 cm, T2:60 days*50 cm, T3:80 days*20 cm, T4:80 days*50 cm for T. diversifolia and T1:60 days*30 cm, T2:60 days*50 cm, T3:90 days*30cm, T4:90 days*50 cm for S. nigra). Results. The productive variables showed significance in T. diversifolia with higher dry matter (DM kg/bush) at 80 days (30.6 ton ha-1 year-1) and S. nigra at 90 days (14.4 ton ha-1 year-1); the number of branches and shoots showed higher values in T4 for T. diversifolia (127.10 branches/bush and 819.65 shoots/bush). The nutritional quality of T. diversifolia and S. nigra was significantly higher at 60 days; with 26.73 % and 26.25% crude protein, digestibility of 75.45 %, and 76.28 %, and net lactation energy of 1.58 and 1.60 Mcal kg-1 DM, respectively. Conclusion. Biomass production (DM) and resurgence capacity increased when harvested at 80 days in T. diversifolia and 90 days in S. nigra; however, a better nutritional quality was presented at cutting ages of 60 days in the high tropic of Nariño, which evidenced its productive potential for cattle feeding.
Copyright (c) 2020 Carolina Guatusmal-Gelpud, Laura Dayana Escobar-Pachajoa, Diego Hernán Meneses-Buitrago, Juan Leonardo Cardona-Iglesias, Edwin Castro-Rincón (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Climatic conditions and jersey cattle dairy production on two altitudinal levels
Introduction. Precipitation, temperature, radiation, and relative humidity vary according to height, this causes the presence of microclimates that affect the productivity of the animals. Objective. Associate the climatic conditions present in the productive systems with dairy production of a pure Jersey herd in two altitudinal floors of the province of Cartago, Costa Rica. Materials and methods. In retrospect, during the year 2016, the productive information of two dairy farms, located at 660 and 1800 m.a.s.l. was evaluated. From the first farm, the records of 61 animals in a twelve-year period (12,083 data) were analyzed; while in the second, the lactations of 387 animals in a five-year period (13,820 records) were analyzed. Observations included: identification of the cow, day of generation of the record, month, year, daily milk production, lactation days, calving number, animal age, temperature, precipitation, solar radiation and average relative humidity. Results. The lactation days, the lactation number (3-5), the age of the animal (3.7 to 5.8 years), and the calving number affected the daily milk production on both farms (p<0.001). At 1800 m, when the precipitation was greater than 5 but less than or equal to 10 mm day-1 and the relative humidity greater than 80 but less than 90 % day-1 (p<0.001), milk production decreased. On the other hand, at 660 m the effect came from relative humidity less than or equal to 70 %. The environmental temperature had a significant effect in both altitudes. Conclusion. The conditions of temperature, humidity, precipitation, and radiation in each ecosystem, generated differences in the productivity of the animals, related to the type of forages and the thermal sensation to which the cattle was exposed, which caused heat or cold stress.
Copyright (c) 2020 Juan Federico Conejo-Morales, Rodolfo WingChing-Jones (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Herd management information systems to support cattle population research: the VAMPP® case
Introduction. Livestock information systems, besides being indispensable for the daily management of the herd, can serve as a basis for research at the population level. Objective. The objective of the study was to analyze the role of the VAMPP® system as a source of information for cattle population research over 32 years of evolution in Costa Rica. Materials and methods. A statistical analysis of the system database (VAMPP®) covering the period between 1987 and 2018 was carried out. Trends in the dissemination and adoption of the system were evaluated according to period, area, production system, and herd size. The use of information for the exploration of trends by breed and area was exemplified. The contribution of the system at the academy level and production of scientific literature was quantified. Results. 2285 herds (88.8 % specialized dairy and 11.2 % dual purpose) were counted with an average of 9.4±7.9 years of follow-up in the VAMPP® system. The areas with greater diffusion were the very humid premontane forest (29 %) and very humid tropical forest (25 %). The average size of the herd was 124±255 adult cows. The system contains records on 404 316 cows, mostly of Holstein (36.3 %), Jersey (24.6 %), and Holstein×Jersey (20.9 %) breeds. The database includes information on 1,249,557 calvings, 16,223,260 records of daily milk production, and 443,108 health events, predominantly related to mastitis (35.6 %) and laminitis (14.1 %). The system has been used for the elaboration of at least 74 investigations leading to academic degrees and the production of 71 scientific articles, mainly related to health and genetic issues. Conclusion. The information obtained from the VAMPP® system has allowed a detailed characterization of the productive performance of local dairy cattle.
Copyright (c) 2020 Z. Sánchez-Hernández, C.S. Galina-Hidalgo, B. Vargas-Leitón, J. Rojas-Campos, S. Estrada-König (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Effect of doses of nitrogen in the agronomy and physiology of yellow passion fruit
Introduction. The passion fruit plant is important as fresh fruit and in the agroindustry, since its rich in minerals and vitamins and also has potential for domestic consumption and exportation. It has been shown that nitrogen (N) has an influence on fruit yield but there is no information on the optimal N range for maximum production. Objective. Determine the agronomic, physiological, and phenological response, yield and quality of fruit in the cultivation of parchita passion fruit against different doses of nitrogen. Materials and methods. At the Universidad Central de Venezuela, Maracay, Venezuela from April 2014 to march 2015, passion fruit plants were planted in a completely randomized design, six replicates, and six plants per experimental unit, a control (8 g N plant-1 (T1)) was evaluated and three doses of N (100 (T2), 200 (T3) and 300 (T4) g plant-1), an a dose of 50 and 300 g plant-1 of P2O5 and K2O, respectively were evaluated. The evaluated variables were: plant height, number of leaves, photosynthesis rate (A), transpiration (E), stomach conductance (Gs), chlorophyll index (CI), total leaf N content in doses at flowering and fruiting, yield, and fruit quality. Results. Higher doses of N obtained higher values in height, number of leaves, plant precocity, chlorophyll index, net photosynthesis, and foliar N content and lower values in T1. The variables Gs, A and E, did not show significant differences between the treatments. A 55 % yield reduction was obtained in the control treatment compared to the 200 g N plant-1 treatment which obtained the highest yield. The average fruit weight was significantly higher in T3. Conclusion. The best nitrogen dose in passion fruit plants was 200 g N plant-1.
Copyright (c) 2020 Gustavo Adolfo Rodríguez-Yzquierdo, Carmen Amalia Basso-de-Figuera, Marta Barrios-García, Rommel Igor León-Pacheco, Mercedes Pérez-Macias (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Pea production and commercialization in the department of Nariño-Colombia
Introduction. Traditional agricultural production systems prevail in the southern region of Nariño, however, the area harvested from transitory potato, corn and beans crops has been decreased. To address this problem, pea planting has been strengthened, which is marketed in local and regional markets. The department of Nariño is the first pea producer in Colombia, and in 2018, 9425 ha were reported, with an average yield of 1.19 t ha-1. The farmers in the study area are traditional and show technical limitations of production and commercialization. Objective. The objective of the investigation was to analyze the production and commercialization of peas in the department of Nariño. Materials and methods. The research was descriptive and allowed to establish costs, production volumes, planting times, product characteristics, prices, and marketing during 2012. The target population included producers, municipal intermediaries, wholesalers and retailers, and association leaders located in the pea-producing municipalities. Results. The Andean variety was the most sown, the post-harvest losses were 52 %, the prices vary due to the seasonality of production, and the greater volume of production was channeled through intermediaries. Conclusions. The production and commercialization of peas in Nariño presents difficulties that requiere sowing planning to balance production volumes, access development credit, train and organize farmers, and foster strategic alliances to guarantee conditions in the value chain.
Copyright (c) 2020 Francisco Javier Torres-Martínez, Carlos Nelson Rivadeneira-Miranda, Álvaro José Castillo-Marín (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Increase okra production with the addition of nitrogen
Introduction. The growth, production, and quality of the okra (Abelmoschus esculentus (L.) Moench) are related to the application of fertilizers with nitrogen (N) being the most prominent, due to the direct relationship with photosynthesis and vegetative growth of the plant. Objective. The objective was to evaluate the agronomic and productivity characteristics of the okra based on the dose of N. Materials and methods. The study was carried out in the experimental area Campus Gurupi, of the Universidad Federal de Tocantins (UFT), in two planting periods (autumn/winter and spring/summer). The experimental design used was randomized blocks (DBC) with six treatments (0, 50, 100, 150, 200, and 250 kg N ha-1) and four repetitions. Urea was used as a source of N. The characteristics evaluated were: productivity, average fruit mass, height and chlorophyll index of the plant. Results. The productivity and height of the plant were higher in the autumn/winter crop. The average mass and chlorophyll index were not influenced by the sowing period. For productivity a linear response was obtained, increasing the dose up to the limit of the dose of N used (250 kg ha-1), with an average value higher than 14 t of fruit. The mean mass and plant height responded linearly to the increase in the dose of N. Nitrogen affected the chlorophyll index, with maximum values of 45.96 and 47.19, observed in the two evaluation periods. Conclusion. The sowing season and the N content in the soil interacted with the height of the plant, being favorable in the period when there was no precipitation. N influenced all characteristics, demonstrating the importance of nitrogen fertilization development okra plants.
Copyright (c) 2020 Valdilene Coutinho-Miranda, Irais Dolores Pascual-Reyes, Aline Torquato-Tavares, João Victor Gonçalves-Carline, Kássio Abel Silva-Sousa, Ildon Rodrigues-do-Nascimento (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Fatty acids composition of genotypes of Jatropha curcas L., in Colombia
Introduction. Jatropha curcas L. (JC) is a specie with the potential to use its oil as a biofuel and its quality is recognized by the composition of the fatty acids present. Objective. The objective of this work was the identification and quantification of fatty acids of JC genotypes of the Jatropha Colombia Collection. Materials and methods. During the years 2012-2014 the experiment was conducted in Espinal-Tolima, Colombia, in a randomized complete block design with fifteen genotypes. The lipid profile of the genotypes was determined by chromatography GC-MS and GC-FID. Results. Ten types of fatty acids were detected in the oil: five saturated (myristic, palmitic, margaric, stearic, arachidic); three monounsaturated (palmitoleic, oleic and eicosenoic), and two polyunsaturated (linoleic and linolenic). The proportion was higher in monounsaturated acids (45.44 %) and polyunsaturated acids (34.18 %) and lower in saturated acids (20.37 %). In the monounsaturated, the oleic predominated (44.62 %); in polyunsaturated linoleic (33.95 %) and in saturated palmitic (12.41 %) and stearic (7.43%). The results found allowed the classification of JC oil as monounsaturated-polyunsaturated (oleic-linoleic), which coincided with what was reported worldwide. Conclusion. Based on the lipid profile, it can be inferred that the oil of the fifteen genotypes evaluated in Colombia is suitable for use as biodiesel.
Copyright (c) 2020 Luis Fernando Campuzano-Duque, Fernando Cardeño-López (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Chemical control of Pogonomyrmex barbatus with corn attractants, in Irapuato, Guanajuato, Mexico
Introduction. Granivorous ants have an economic and ecological impact because they are considered agricultural pests that transport seeds and defoliate cultivated plants. Objective. The objective of this work was to evaluate the effectiveness of the insecticides Imidacloprid and Novaluron in mixture with three cornflour-based attractants for the control of Pogonomyrmex barbatus in field trials in Irapuato, Guanajuato, Mexico. Materials and methods. This research was conducted from August to November 2014, six tratments were considered, the first three consisted of the mixture of Imidacloprid with cornflour (in finely milled pellet, in milled pellet and without pelletizing), the fourth was Novaluron combined with cornflour in milled pellet, and the last two consisted only of cornflour (in finely milled pellet and without pelletizing), in addition to an absolute control. Individuals counts per minute were performed before (reading at 0 h), and after the application of the treatments (readings at 1, 24, 72, 144, and 240 h) on the outside of three anthills previously selected for this purpose. The analysis of variance of the design was completely randomized according to sub-subdivided stripes with three repetitions, and three factors that were the following: six treatments and the absolute control, six readings over time including the count prior to the application of the treatments and the three anthills. Results. There were highly significant statistical differences for the factors: treatments and readings, as well as for the interaction between both. Conclusion. The treatments with insecticide showed their maximum control at 72 h of its application, the best were the Imidacloprid combined with cornflour in two presentations (in milled pellet and without pelletizing), showing greater effectiveness after 24 h of its application.
Copyright (c) 2020 Manuel Darío Salas-Araiza, Luis Gerardo Lara-Álvarez, Oscar Alejandro Martínez-Jaime, José Antonio Díaz-García (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Leaf litter and Mycena citricolor inoculum on the American leaf spot epidemic
Introduction. The American leaf spot caused by Mycena citricolor is among the main coffee diseases in Costa Rica. Cyclic attacks occur approximately every fourteen years, related to increased rainfall and inoculum. Objective. Determine the impact of litterfall and primary inoculum on the epidemiology of this disease. Materials and methods. In coffee plantations located in the coffee region of Tarrazú, Costa Rica, the effect of the manual elimination of diseased leaves attached to the plant and the layer of fallen leaves on the American leaf spot epidemic in 2013 and 2014 was assessed. 1200 branches were evaluated in an experiment of divided plots, where the four treatments were obtained by combining the “with and without” levels for each factor. The disease was described by quantifying the number of diseased leaves, lesions, and geminifers. The disease development curves were constructed and the area under the curve was calculated for each variable. The growth and defoliation of coffee plants was calculated. Results. Based on the disease incidence curve for each treatment in each year, it was determined that the logistic growth of epidemics is the best fit model. The rates of apparent infection (r) were close to 0.04 units per day in 2013 and there was no significant statistical difference in the developed epidemics; but for 2014, where they varied between 0.03 and 0.05. A main effect of the initial inoculum factor was observed on the presence or absence of litterfall. Conclusion. Litterfall had no significant effect on the development of the American leaf spot epidemic. This is the first investigation that determines the impact of possible sources of inoculum other than the lesions present in coffee leaves.
Copyright (c) 2020 Milagro Granados-Montero, Jacques Avelino, Felipe Arauz-Cavallini, Sebastián Castro-Tanzi, Natalia Ureña (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Productive performance of seven soybeans genotypes in acid soils of the Colombian Orinoquía
Introduction. In Colombia, soy is one of the main raw materials for the production of feed for animals, demand that was only satisfied in 7% in 2007. In the country, this legume is only produced in the Orinoquía region, as part of the rice-corn-soybean rotation system, and its current commercial production is associated with the Soyica P-34 (Altillanura) and Corpoica Superior 6 (Piedemonte) varieties, which are susceptible to Cercospora sojina, which compromise yield. Objetive. The objective of this work was to identify soy genotypes with specific adaptation for acid soils oxisoles (Altillanura) and inceptisoles (Piedemonte) with superior grain yield a lower affectation by Cercospora sojina K. Hara. Materials and methods. An agronomic evaluation test (PEA) consisting of seven genotypes and two commercial varieties was carried out as controls in six localities located in two sub-regions of the Orinoquía (Altillanura and Piedemonte) during 2011, in a randomized complete block design (DBCA) and four repetitions. The AMMI model and its biplot graph were used to determine the phenotypic stability with the variable grain yield. Results. The AMMI model explained 81.8% of the genotype x locality interaction with the first two main components, the biplot graph allowed to identify three soy genotypes candidates for variety, two with specific adaptation for the Altillanura (L-062 and L-103), and one for Piedemonte (L-189). These genotypes showed higher grain yields by 8% and a lower affectation by Cercospora sojina in relation to commercial witnesses. Conclusion. The study allowed three soy genotypes to be selected and registered as commercial varieties in the National Cultivation System of the ICA as Corpoica Guayuriba (L-189), Corpoica Achagua (L-062) and Corpoica Iraca (L-103), according to their specific adaptation by sub-region.
Copyright (c) 2020 Samuel Caicedo-Guerrero, Yuli Tibocha-Ardila, Luis F. Campuzano-Duque, Deisy L. Flórez-Gómez, Jorge Arguelles-Cardenas (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Genotype by environment interaction of nine cotton varieties for inter Andean Valleys in Colombia
Introduction. The use of stability estimators for agronomic characteristics of interest allows understanding the behavior of the genotype in relation to those environmental factors that influence its expression. Objective. The objective of this study was to determine genotype by environment (GE) interaction to select cotton varieties with a high seed yield potential and fiber percentage. Materials and Methods. Nine varieties of transgenic cotton were evaluated in ten localities distributed in two geographically different ecoregions: geographical valleys of the Magdalena and Cauca rivers, by means of random complete block design, between the months of March and August in 2013. Results. Cotton seed yield had significant GE interaction, where the three principal components (PC) of the Additive Main Effects and Multiplicative Interaction (AMMI) model were significant (p<0.01), with contributions of 86.9, 6.4, and 3.3 %, respectively. The average yield for the two ecoregions were 3.3 t ha-1 (Magdalena river geographical valley) 4.5 t ha-1 (Cauca river geographical valley), and for all the evaluated localities in the ecoregions was 3.9 t ha-1. Fiber percentage did not present significative GE interaction and had an average value of 43,34%. The V004 variety showed the best performance with an average yield of 4.9 t ha-1. The varieties with greater adaptability were V001 and V002. A high correlation was observed between the most productive varieties and the most productive environments. Conclusion. The differential behavior between varieties and localities for yield allowed to select varieties for specific environments, or with phenotypic plasticity for several environments.
Copyright (c) 2020 Julian Roberto Mejía-Salazar, Carlos Hernando Galeano-Mendoza, Esteban Burbano-Erazo, Franco Alirio Vallejo-Cabrera, Miguel Arango (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Environmental stratification of rice by genotype x environment interaction analysis using five methods
Introduction. Venezuela has more than two million hectares suitable for rice production, of which about the 25% are exploited, under the production system with flood irrigation with various agronomic management technologies and environments that could affect the phenotypic expression of the genetic materials. Objective. The objective of this work was to quantify the magnitude of the environmental genotype interaction (IGA) to stratify the irrigated rice environments through five analytical methods and determine their association. Materials and methods. Eight rice genotypes were evaluated in twelve environments resulting from the combination of localities and planting seasons in the regions of the Central and Western Plains of Venezuela, during the years 2012-2013. The stratification of environments was made based on five methods: traditional Lin (TL), Euclidean distance (ED), simple percentage of IGA (% SP), Pearson correlation (rxy), and factor analysis (AF). The randomized complete block statistical design was used with three repetitions in 20 m2 plots. Results. ANOVA detected significant IGA, explaining 35% of the total variation. Favorable environments for rice represented 33%. The methods used TL, ED, % SP, rxy, and AF grouped the twelve irrigated rice environments into 10, 5, 8, 10, and 3 groups respectively; they were not efficient in identifying different environments when different planting seasons were used in the same locality. Conclusions. The factor analysis method was more efficient in identifying homogeneous environments, complemented with % SP and TL methods that presented moderate association. The Bancos of San Pedro and Asoportuguesa environments were more informative and indicated for the evaluation of rice genotypes. The opposite occurred with the Araure, Algodonal, and Torunos localities.
Copyright (c) 2020 Marco Acevedo-Barona, Rubén Silva-Diaz, Rosa Álvarez-Parra, Orlando Torres-Angarita, Edicta Reyes-Ramones (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
The value chain of tree tomato (Solanum betaceum) network in Ecuador
Introduction. The fruit and vegetable sector in Ecuador has shown promising performance in domestic and international markets. Likewise, this sector has faced problems of a social, economic and productive nature in its structure and articulations, which until now require intervention. Objective. The objective of this study was to analyze in a descriptive way the structure of the tree tomato agro-food network. Materials and methods. This study was carried out in the provinces of Cotopaxi, Tungurahua, and Chimborazo, Ecuador, during the period between the second quarter of 2016 and the end of 2017. The study applied a systemic methodology aimed at the identification and characterization of stages, agents and activities (primary and support), and the analysis of network governance mechanisms. Results. The present study showed the main social and productive characteristics, horizontal and vertical sizing; and the proposal of strategies focused on improving their productive performance. Conclusions. The inclusion of women, the sense of associativity of processors and distributors, and the training of producers in topics related to post-harvest, and good agricultural practices, would significantly improve the economic performance of the network, and also encourage greater participation of the agents involved. The network requires increasing the area allocated to tree tomato cultivation, and the application of greenhouse production systems that increase yields.
Copyright (c) 2020 Carlos Moreno-Miranda, José Isaac Molina, Jacqueline Ortiz, Carla Peñafiel, Raúl Moreno (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Selection criteria in tomato lines with determinate growth habit
Introduction. The selection of genotypes with a determined growth habit in tomato should contemplate adequate selection criteria to increase the efficiency of the plant breeding program. Objective. The objective of this research was to estimate selection criteria for “chonto” tomato lines with determined growth habit. Materials and methods. The research was developed in the Universidad Nacional de Colombia campus Palmira in 2016, using seven determinate habit growth lines (D) and a control with undetermined habit growth. The heritability in a broad sense (h2g), coefficient of environmental variation, coefficient of genetic variation, selection efficiency, and genetic gain was determined, in morphologic, phenological, quality fruit, fruit shape, and productions parameters using the RELM/BLUP process, from the SELEGEN software. Results. Three ranges of h2g were found, the first with values of h2g greater than 0.76, the second between 0.53 and 0.38, and the third with a value less than 0.38. The highest values of h2g were for final height plant with 0.92, height plant to harvest with 0.88, production per plant with 0.83, days to flowering with 0.83, fruit number with 0.82, and days to harvest with 0.82. For genetic gain it was found that the control presented the highest values within the main parameters for final height plant, plant height to harvest, internode length, days to harvest, crop duration, soluble solids content, number of fruits per plant, weight fruit, and plant production; however, in some parameters such as height and phenology for effects of selection by habit of determined growth lower values were better. Conclusion. Genetic parameters were evidenced that could be considered as selection criteria for “chonto” tomato lines with determined growth of habit.
Copyright (c) 2020 Esteban Burbano-Erazo, Iván Javier Pastrana-Vargas, Julián Roberto Mejía-Salazar, Franco Alirio Vallejo-Cabrera (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Ecosystem-based adaptation: effect of shade trees on ecosystem services in coffee plantations
Introduction. The management of shade trees in a production system is considered an ecosystem-based adaptation practice capable of providing multiple ecosystem services. Objective. Contribute to the understanding of the effects of trees in coffee plantations on ecosystem services for provisioning and regulation and how the analysis of relationships between services can contribute to improve the design and management of these systems. Development. The study was carried out between July and October 2017. Shade trees have an effect on coffee yield, attributed to their influence on the regulation of fruit load. This effect can have positive results with an adequate agroforestry management, as it would reduce extreme biennial fluctuations in coffee production. The trees also regulate the climate within the coffee plantation (microclimate), in addition, they have positive effects on soil fertility, the amount of organic matter, the recycling of nutrients, decrease soil evaporation, reduce erosion and sequester carbon. However, there are some aspects that are still complex and sometimes contradictory. Overall, the documentation of the positive aspects of the trees on provisioning and regulation services is greater than the negative ones. Conclusion. This review shows an effect of shade trees on ecosystem services. Knowledge of these effects, considering the interest and expectations of the social systems, must be complemented with analysis of relationships between services with the aim to identifying best agroforestry practices or model systems that can provide multiple services simultaneously.
Copyright (c) 2020 Rogelio Villarreyna, Jacques Avelino (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Effect of temperature and scarification over the germination of Ischaemum rugosum Salisb.
Introduction. The rupture of the Ischaemum rugosum Salisb. latency is a critical aspect of its physiology, so its knowledge is indispensable to establish accurate measurements regarding its management. Objective. Determine if storage temperature and scarification influence the germination of I. rugosum under controlled conditions. Materials and methods. The work was carried out in October 2015 at the Fabio Baudrit Moreno Experimental Station and the Official Seed Quality Analysis Laboratory, both at the Universidad de Costa Rica. The effect of scarification (seeds with glumes and seeds without glumes), the seed storage temperature (refrigerated at 5 ¡C and environment temperature 23.9 °C), and the germination chamber temperature (27 °C and 30 °C) were evaluated. Germinated seeds were counted for each treatment. Results. Double interactions were significant. Seed stored at room temperature had the advantage of higher germination than non-scarified seed (2.35 to 1), and in this type of seed occurs equally in the two temperatures of the germination chamber. In relation to the seed stored in refrigeration, scarified seed had an advantage of germinating at 11.9 to 1 over the non-scarified seed. In the case of germination temperature, 27 °C had an advantage of 11.3 to 1 over 30 °C. Conclusion. The storage and germination temperature had an influence on the scarified and non-scarified seed’s germination.
Copyright (c) 2020 Mary Pamela Portuguez-García, Ana María Rodríguez-Ruiz, Carolina Porras-Martínez, María Isabel González-Lutz (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
White spot syndrome virus and Enterocytozoon hepatopenaei in shrimp farms in Costa Rica
Introduction. The white spot syndrome virus (WSSV) causes systemic destruction of ectodermal and mesodermal tissues in shrimp and can cause 100 % mortality. Enterocytozoon hepatopenaei (EHP) is an intracellular microsporidian that causes lysis of epithelial cells in hepatopancreatic tubules in shrimp. Objective. Detect the presence of WSSV and EHP in fifteen shrimp farms in the Gulf of Nicoya and the Central Pacific from Costa Rica. Materials and methods. Between January 2017 and July 2018 water during the filling process of the pond, postlarvae, and juvenile shrimp of Penaeus vannamei was collected, during a production cycle in each one of the fifteen farms. Samples were analyzed through polymerase chain reaction (PCR) using primers and protocols to detect the VP41B gene in WSSV, and the small subunit ribosomal RNA gene of EHP. Results. The presence of WSSV was detected in one farm, while EHP was not detected in any of the fifteen farms. The sequencing of the amplified segments of the VP41B gene showed 100 % identity with isolated shrimp sequences in Taiwan and Mexico. Conclusion. WSSV was detected at a very low frequency and EHP was not detected in this study. It is necessary to continue monitoring these agents in the country’s shrimp farms.
Copyright (c) 2020 Nelson Peña-Navarro, Ruth Castro-Vásquez, Gaby Dolz (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Soybean protease inhibitors increase Bacillus thuringiensis subs. israelensis toxicity against Hypothenemus hampei
Introduction. The coffee berry borer (Hypothenemus hampei Ferrari, CBB) is one of the most devastating pests on coffee plantations around the world. Although CBB is susceptible to the effect of δÐendotoxins of Bacillus thuringiensis subs. israelensis (Bti) at laboratory level, the efficacy of this control method is poor in the field, presumably due to the inactivation by digestive proteases different to those required for protoxin activation. Objective. To study whether the addition of a soybean flour extract enriched with protease inhibitors (PI), mixed with Bti crystals and spores (Bti-sc) in an artificial diet, could improve the toxicity of Bti against CBB. Materials and methods. This study was performed in San José, Costa Rica, between 2012 and 2013. A set of adult female CBB insects was exposed to a mixture containing different concentrations of a partially purified soybean meal extract with active PI and lyophilized Bti-sc, and were tested through a bioassay in artificial diet to estimate the sub-lethal concentration (LC50). The mortality results were validated by observing the dissected midgut, whose ultrastructure was analyzed by transmission electron microscopy. Results. The soybean extracts partially degraded the Bti-sc complex, it reduced its LC50 by almost four times (from 1.135 to 0.315 µg µl-1) and enhanced CBB mortality in a concentration-dependent manner. Histological analyses of the midgut confirmed this synergistic effect, since severe epithelial damage to the intestinal epithelium of CBB exposed to Bti-sc + PI was visualized compared to Bti-sc alone. Conclusions. The combination of a soybean extract enriched in PI and Bti-sc enhanced the mortality effect over CBB, which was confirmed by the midgut collapse. Soybean flour is a cost-effective supplement that could increase Bti effectiveness against CBB and delay the appearance of biological resistance.
Copyright (c) 2020 Esteve Mesén-Porras, Sergio Dahdouh-Cabia, Catherine Jimenez-Quiros, Rebeca Mora-Castro, César Rodríguez, Adrián Pinto-Tomás (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Spodoptera spp. monitoring in sugarcane: use of sex pheromone traps
Introduction. The fall armyworm, Spodoptera frugiperda, is one of the world’s most devastating pests. Although originally from the Americas, this insect has become a global food security threat. The reason is that its polyphagia and adaptability combine with the effects of climate change. In Costa Rica, the species of the Spodoptera order, are considered minor pests in sugarcane production. Nevertheless, there is a knowledge gap in population dynamics of the moths of this genus. Objective. Monitor the populations of S. frugiperda, S. sunia, and S. exigua species in a sugarcane field. Materials and methods. The study was conducted in a sugarcane plantation of the variety CC 01-1940, located in Guanacaste, Costa Rica between February 2018 and May 2019. Sexual pheromone-baited traps formulated for S. frugiperda, S. sunia, and S. exigua were used, each pheromone corresponded to a treatment and ten replicates of each one were established. The abundance of each species was compared and correlated with several climatological variables. Results. The highest percentage of catches corresponded to S. frugiperda, followed by S. sunia, while the captures of S. exigua were marginal. For both S. frugiperda and S. sunia, the dry season months favored larger populations, so factors such as higher average temperature, thermal amplitude, and lower relative humidity were associated with higher captures in the traps. Conclusions. Increases in the average temperature and decrease in rainfall periods could increase the incidence of Spodoptera genus as pests in sugarcane production.
Copyright (c) 2020 https://creativecommons.org/licenses/by-nc-nd/4.0
Mapping of a gene involved in distorted segregation in interspecific tomato populations
Introduction. Distorted segregation (SD) occurs when the expected genotypes do not correspond to those observed, which favors single parent alleles. This phenomenon was observed in intermediate populations from the cross between Solanum pimpinellifolium and the Moneymaker cultivar of Solanum lycopersicum, developed during the construction process of a library of introgression lines. Objective. Obtain informative recombinants that allow physically mapping a region with SD associated with the wild Solanum pimpinellifolium species. Materials and methods. The research was carried out at the Institute of Molecular and Cellular Biology of Plants (IBMCP) attached to the Higher Council for Scientific Research (CSIC) based at the Universidad Politecnica de Valencia, Spain. A population of 2000 plants was screened to identify recombinants in that region, with a modification of the high-resolution melting technique (HRM-Multiplex). These recombinants were self-fertilized, and through the Chi-square statistic it was determined whether SNP markers identified within the target region had a normal (1:2:1) or distorted segregation for each informative recombinant selected. Results. Fifty-four informative recombinants were generated and identified, grouped into 10 bins according to the physical recombination site. It was possible to delimit the region with distorted segregation until obtaining a final size of 84 Kb, which was located at the distal end of the long arm of chromosome 4. This region contains a large number of genes, some of which are related to fertilization processes, sterility and cell division among others, which could be related to the studied phenomenon. Conclusion. A gene was found, that causes a segregation distortion in an interval of 84 Kb and possibly is the gene Ge described by Rick in 1966.
Copyright (c) 2020 Walter Barrantes-Santamaría, Antonio Granell, Antonio J. Monforte (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Molecular study of six strains of Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) and Cochliomyia macellaria
Introduction. The cattle borer worm, Cochliomyia hominivorax (Coquerel), is an economically important pest for warm-blooded animals, mainly cattle. Objective. Molecularly characterize six strains of Cochliomyia hominivorax (Coquerel) and the Cochliomyia macellaria species using the mtDNA sequences. Materials and methods. The study was conducted during 2006 and 2007, using six strains from colonies of Mexico, Panama, and Costa Rica, located in the Molecular Biology Laboratory of the Smithsonian Tropical Research Institute, Panama. Three out of six primers were optimized and evaluated, using the cyclic sequencing method. Parsimonia, NJ (Neighbor-Joining), Maximum Likelihood, and Bayesian analyzes were performed to establish the phylogenetic relationships between the strains. Three primers used for C. hominivorax were evaluated for C. macellaria. Results. The regions of the mitochondrial genome NADH4-tRNA-NADH5 were obtained. All the analyzes showed the same topology forming four defined clades. The first formed by the strains from Oaxaca and Quintana Roo, the second by the strains from Chiapas, the third by the strains from Costa Rica and Panama, and the fourth by the population from Brazil, obtained from GenBank. In C. macellaria two primers were able to amplify the NADH4 region and one NADH5 region. Conclusion. The amplifications obtained in this research provide information to continue the molecular studies between the species of C. macellaria and C. hominivorax; also to identify the geographical origin of the strains.
Copyright (c) 2020 Claudia Elizabeth Toledo-Perdomo, Steven R. Skoda (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0