Abstract Introduction. Seedlings formation under controlled conditions is crucial for cultivating species like strawberry. With LED artificial lighting technology allowing greater control over light, variations in components such as wavelength and intensity can be manipulated to generate seedlings with different characteristics. However, there is a need to generate information for the development of precise and efficient light control practices. Objective. The evaluate strawberry seedling formation under different intensities of violet, blue, and red LED light. Material and methods. The study was conducted in 2020 at the Plant Genetics Laboratory of the Department of Agronomy at the Universidad de Guanajuato, Guanajuato, Mexico. Seeds from San Andreas variety fruits were collected, and seedlings were grown under violet, blue, and red LED light at high, medium, and low intensities. Color determinations of cotyledon area, Chroma saturation index, and Hue angle were performed. Additionally, physio-technical, chemical, and antioxidant activity variables were measured. Results. The most suitable treatments were high and medium intensity violet light, as well as high intensity blue light, with germination range exceeding 60 %. Seedlings did not elongate or thin out and exhibited the largest cotyledons areas and chlorophyll concentrations. Furthermore, these light treatments consumed, on average, 31.2 % less electrical energy. Conclusions. In addition to white light, the most suitable treatments for strawberry seedlings formation were high and medium intensity violet light, as well as high intensity blue light. It is suggested to evaluate violet and blue light treatments in other cultivars to confirm their positive effect on strawberry seedlings. Red light limited germination and showing higher antioxidant activity.

Resumen Introducción. La formación de plántulas en condiciones controladas es fundamental para cultivar especies como la fresa. Dado que la tecnología de iluminación artificial LED ha permitido un mayor control de la luz, la variación de componentes como la longitud de onda y la intensidad pueden ser manipulados para generar plántulas con diferentes características. Sin embargo, es necesario generar información para el desarrollo de prácticas precisas y eficientes en el control de la luz. Objetivo. Evaluar la formación de plántulas de fresa en diferentes intensidades de luz LED violeta, azul y roja. Materiales y métodos. El estudio se realizó durante 2020 en el Laboratorio de Genética Vegetal del Departamento de Agronomía de la Universidad de Guanajuato, Guanajuato, México. Se recuperaron semillas de frutos de la variedad San Andreas y se sembraron plántulas en luz LED violeta, azul y roja a intensidades alta, media y baja. Se realizaron determinaciones de color del área del cotiledón, índice de saturación de color y ángulo Hue. Además, se midieron variables fisiotécnicas, químicas y actividad antioxidante. Resultados. Los tratamientos más adecuados fueron luz violeta de intensidades altas y medias; así como luz azul de alta intensidad, debido a que el porcentaje de germinación superó el 60 %. Las plántulas no se alargaron ni adelgazaron, presentaron las mayores áreas de cotiledones y concentraciones de clorofila. Además, estos tratamientos de luz consumieron en promedio 31,2 % menos energía eléctrica. Conclusiones. Además de la luz blanca, los tratamientos más adecuados para la formación de plántulas de fresa fueron la luz violeta a alta y media intensidad, así como la luz azul a alta intensidad. Se sugiere evaluar los tratamientos de luz violeta y azul en otros cultivares para confirmar el efecto positivo en las plántulas de fresa. La luz roja limitó la germinación y mostró mayor actividad antioxidante.

Resumen Introducción. El virus de la fruta rugosa marrón del tomate (ToBRFV) se reportó por primera vez en Israel y Jordania en 2014, causa daños en cultivos de jitomate en agricultura protegida. Objetivo. Recopilar información de la distribución conocida, situación actual y métodos de detección del ToBRFV. Desarrollo. Entre 2018 y 2019 se confirmó la presencia del virus en México, Estados Unidos, China, Alemania, Turquía, Reino Unido e Italia. Para la detección del virus se ha empleado microscopía electrónica y pruebas serológicas, pero estas no pueden diferenciar el ToBRFV de otros tobamovirus, la técnica de diagnóstico más eficaz para la detección son oligonucleótidos específicos desarrollados a partir de los aislados de Israel y Jordania. Los protocolos de higiene son el paso más importante en la prevención de las infecciones. Conclusión. Los esfuerzos para controlar el ToBRFV se centran actualmente en el uso de estrictas prácticas de sanidad y detección en semilla y planta, mediante técnicas moleculares de reacción en cadena de polimerasa con transcriptasa inversa (RT-PCR) con oligonucleótidos específicos, para evitar falsos positivos.

Abstract Introduction. The tomato brown rugose fruit virus (ToBRFV) was first reported in Israel and Jordan in 2014, causing damage to tomato crops in protected agriculture. Objective. To collect information on the known distribution, current situation, and detection methods of ToBRFV. Development. Between 2018 and 2019, the presence of the virus was confirmed in Mexico, the United States, China, Germany, Turkey, the United Kingdom, and Italy. Electron microscopy and serological tests have been used to detect the virus, but these cannot differentiate ToBRFV among other tobamoviruses. The most effective diagnostic technique for detection is specific oligonucleotides developed from the isolates from Israel and Jordan. Hygiene protocols are the most important step in preventing infections. Conclusion. Efforts to control ToBRFV are currently focused on the use of strict sanitation and detection practices in seed and plant, using molecular reverse transcriptase polymerase chain reaction (RT-PCR) techniques with specific oligonucleotides, which avoid false positives.

Resumen En los últimos cinco años en México se registró un incremento de 189,50 a 13 219,84 hectáreas, en la superficie de cultivo de girasol en temporal, particularmente en el estado de Guanajuato se sembró aproximadamente 450 hectáreas en 2016. Esta forma de cultivo requiere de planeación que contemple variables bioclimáticas para el óptimo desarrollo y rendimiento. El objetivo del presente trabajo fue determinar las áreas con potencial bioclimático para el establecimiento del cultivo de girasol en temporal en el estado de Guanajuato. Durante el ciclo otoño-invierno del 2016 se monitorearon y se estratificaron 45 parcelas de girasol, distribuidas en once municipios, en las que se registró el rendimiento asociado a temperatura máxima y mínima, humedad relativa, radiación solar, precipitación y evapotranspiración. Los datos de parcelas con un rendimiento mayor a 1,89 t/ha se utilizaron para generar polígonos con una saturación de 56 puntos de abundancia, para calcular la distribución potencial mediante el programa Maxent, con 23 variables bioclimáticas como predictores. Las variables con mayor contribución porcentual a la distribución potencial fueron: temperatura promedio del cuatrimestre más seco, altitud, régimen de humedad y perfil edáfico. Las áreas potenciales para el establecimiento del cultivo suman una superficie total de 317 028 hectáreas, donde el clima predominante es semicálido subhúmedo, temperatura media anual de 20 °C, precipitación media anual de 600 a 800 mm y una altitud de 500 a 1500 msnm.

Abstract In Mexico, in the last five years, there was a 189.50 to 13 219.84 hectares increase in sunflower crop surface under rainfed conditions. Particularly, in 2016, in the state of Guanajuato, approximately 450 hectares were planted. Cultivation under rainfed conditions requires planning including bioclimatic variables to reach the optimal crop yield and development. This work aims to identify bioclimatic potential areas for sunflower cultivation under rainfed conditions in Guanajuato. In autumn-winter 2016, 45 sunflower fields (distributed in eleven towns) were monitored and stratified. Crop yield associated to maximum and minimum temperature, relative humidity, solar radiation, precipitation and evapotranspiration were recorded. The data from fields with higher yield than 1.89 t/ha were used to generate polygons with a saturation of 56 abundance points, to calculate the potential distribution using the Maxent software, with 23 bioclimatic variables as predictors. The variables with the highest contribution percentage to the potential distribution were: average temperature of the driest quarter, altitude, moisture regime, and edaphic profile. The potential areas for sunflower cultivation had a surface of 317 028 hectares where the predominant climate is sub-humid warm, the annual mean temperature is 20 °C, the annual mean rainfall is 600 to 800 mm, and the altitude ranges from 500 to 1500 masl.

RESUMO. A eficiência do uso da água (UEA) foi proposta como uma alternativa para mitigar os efeitos das mudanças climáticas na agricultura e reduzir a pressão sobre os recursos hídricos, principalmente em espécies com altos requerimentos de água que são cultivadas sob condições de sequeiro. O objetivo deste estudo foi caracterizar o UEA instantâneo, integral e molecular de quatro cultivares de feijão, contrastando sua resposta em condições de água limitadas para comparar os mecanismos componentes desta característica entre cultivares tolerantes à seca. Os resultados indicaram que os cultivares tolerantes aumentaram seu UEA instantâneo em comparação aos suscetíveis; entretanto, houve diferença entre as cultivares, uma vez que Pinto Villa apresentou maior condutância estomática e taxa de transpiração, levando a um custo maior de água para produção de sementes do que Pinto Saltillo. Além disso, os genes EUA de ycf2, rrn16, rpoC2, hardy, ndhK, erecta e ycf1 foram apenas sobreexpressos em Pinto Saltillo sob condições de água limitadas, o que se revelou ser a cultivar mais eficiente do UEA. Portanto, os mecanismos componentes da UEA são diferentes mesmo entre as cultivares tolerantes à seca e os mecanismos pelos quais as cultivares tolerantes aumentaram sua UEA instantânea e integral foram diferentes.

ABSTRACT. The water-use efficiency (WUE) has been proposed as an alternative to mitigate the effects of climate change in agriculture and to reduce pressure on water resources, mainly in species with high water requirements which are grown under rainfed conditions. The aim of this study was to characterize the instantaneous, integral and molecular WUE of four bean cultivars contrasting in their response under limiting water conditions to compare the component mechanisms of this trait between drought tolerant and susceptible cultivars. Results indicated that tolerant cultivars increased their instantaneous WUE in comparison to susceptible ones; however, there was a difference between cultivars since Pinto Villa had a higher stomatal conductance and transpiration rate, leading to a higher water cost to produce seed than Pinto Saltillo. Furthermore, ycf2, rrn16, rpoC2, hardy, ndhK, erecta and ycf1 WUE genes were only overexpressed in Pinto Saltillo under limited water conditions, which turned out to be the most WUE efficient cultivar. Therefore, the component mechanisms of WUE are different even between drought tolerant cultivars and the mechanisms by which the tolerant cultivars increased their instantaneous and integral WUE were different.