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Introduction: The list of threatened species is enhancing and needs to be revised by integrating plant tissue culture tools with conventional techniques that support the appropriate management of these species. Objective: To assess the effects of the growth regulators for the induction of somatic embryos from mature seeds, shoots, and compact green callus of Echinocactus parryi Engelm. and the histological analysis of the embryogenic structures. Materials and methods: A completely randomized design was utilized to evaluate three types of explants (apical, medium, and basal) cultured on basal Murashige & Skoog media (MS) with different growth regulators concentrations (2, 4-D [dichlorophenoxy acetic acid], BAP [6-benzylaminopurine] and kinetin, at four levels: 0.5, 1, 1.5, and 2 mg∙L -1 ). Histological analysis of the embryogenic structures was performed. Results and discussion: The 2, 4-D induced both embryogenic and organogenic callus from seeds and shoot explants. The globular stage did not evolve to their maturity, presumably because of 2, 4-D accumulation. The compact callus explants were the more efficient to induce 19.2 somatic embryos per explant when they were cultured in the medium with 0.5 mg∙L -1 kinetin. However, the latest phases did not germinate, probably due to abnormalities generated by genetic and epigenetic changes in the DNA that can cause abnormal somatic embryos. The histology image demonstrated that the globular and torpedo structures were visible under a microscope showing stained nucleus and numerous starch grains. Conclusions: E. parryi is a species that can produce a high number of embryogenic structures, which represents a great potential to grow massive plants.

Es necesario actualizar la tecnología sobre la respuesta agronómica de nuevas variedades de trigo con relación a condiciones agroclimáticas con el fin de dar alternativas de mayores rendimientos y calidad de grano. El objetivo del estudio consistió en probar en tres tipos de suelo en el noroeste del estado de Chihuahua para las siguientes semillas de trigo: Rayón-F89, Roelfs-F2007, Norteña-F2007, Cachanilla-F2000, Delicias-F81, Kronstad-F2004 y Luminaria-F2012. El diseño experimental fue completamente al azar con cinco repeticiones; donde la unidad experimental fue de 1 m2 y las medias fueron separadas con la comparación múltiple con la prueba de Tukey al 0.05. Las practicas agronómicas fueron conforme las del manejo del agricultor. Se registraron los datos de las siguientes variables: contenido de proteína en grano, altura de la planta, humedad de grano, peso hectolítrico, longitud de la espiga, granos por espiga, rendimiento grano y biomasa total. Resultados relevantes en cuanto a rendimiento de grano por tipo de suelo, fueron: la variedad Rayón F-89 con 9.32 Mg ha-1 en sitio El Camello (suelo Calcisol); la variedad Kronstad con 7.9 Mg ha-1 en el sitio El Capulín (suelo Vertisol); y la variedad Roelfs con 11.3 Mg ha-1 en el sitio Placitas (suelo Fluvisol). No se detectó efecto significativo entre variedades para peso hectolítrico. La proteína en grano fluctuó de 10.4 a 16.7% y el mayor contenido fue en la variedad Delicias en suelo Fluvisol; es decir, el efecto genotípico fue más significante que la localidad para la variable proteína de grano. Se recomiendan las variedades Kronstad, Roelfs y Rayón para las zonas productoras del noroeste del estado de Chihuahua.

Antecedentes: El trompillo es asociado por hongos endofíticos septados (HOS) y micorrizas arbusculares (MA) en ecosistemas tropicales, pero no se ha estudiado su colonización en cada etapa fenológica durante las estaciones del año en una zona urbana árida. Preguntas: ¿Cuáles estructuras fúngicas ocurren simultáneamente y están relacionadas con cada etapa de crecimiento del trompillo? Especies de estudio: Solanum elaeagnifolium Cav. Sitio de estudio y fecha: Ciudad Juárez, Chihuahua, México, 2014. Método: Las raíces se trataron con una tinción dual de azul de tripano y sudan IV para distinguir microscópicamente las estructuras de la colonización de ambos hongos en el ciclo de vida del trompillo en las cuatro estaciones del año. Se evaluó el promedio de sus estructuras fúngicas y su colonización total por milímetro de longitud de raíz. Resultados: La colonización simultánea de los hongos fue en todas las estaciones cuya diversidad morfológica estuvo relacionada con la fenología del hospedero. El promedio de la colonización de sus estructuras de ambos hongos (HOS: 64.2 ± 7.2 y HMA: 31.5 ± 3.2 por mm de longitud de raíz) representaron la mayor significancia de asociación de las raíces en primavera. Las hifas hialinas como las estructuras activas de los HOS y los arbúsculos de los HMA fueron consistentes en las estaciones del año. Conclusiones: Este es el primer reporte en mostrar la asociación micorrízica tipo ‘Arum’ y describir la co-ocurrencia de los HMA y los HOS en relación con la fenología del trompillo por estación del año en una zona urbana del Desierto Chihuahuense.

Windblown dust in desert areas can have serious impact on human health by inhaling f ine dispersed mineral particles as well as microorganisms as fungi. There is a lack of information above the microscopic fungal diversity in north Mexico; the aim of this study was to determine the arid soil micro-fungal genus in the municipalities of Ascension and Ciudad Juarez, MX bordering with United States. A Surface soil samples were collected at eight sites identif ied as the source of the dust storms. A total of 234 soil samples were analyzed for moisture content, texture and fungal genus. Soil moisture content was lower than 4% at 3 cm depth from surface. Predominant soil textural classes were clay loam and sandy clay loam, but high variability in percentages of clay, silt, and sand was observed. Fourteen fungal genera were found, Aspergillus sp. was the most dominant followed by Rhizopus sp., Phytium sp., Alternaria sp., and Bipolaris sp. Dominance of the Aspergillus sp. fungus in this study is important because is toxic and cause serious health problems including bleeding in the lungs, and the others genus have serious effects on human respiratory system, also are pathogenic to many plants and animals.

Echinocactus parryi, es una especie amenazada y endémica del municipio de Juárez, Chihuahua, México que presenta importantes limitantes para su propagación. El objetivo de este trabajo fue estudiar el efecto de los reguladores de crecimiento, concentración de calcio (Ca2+), pH del medio y concentración de gelificante en la respuesta morfogenética de E. parryi. Las semillas se germinaron en medio de Murashige y Skoog (MS) al 25% de la concentración de sus sales (¼ MS). Los epicotilos se cultivaron en posición invertida en medios con diferentes concentraciones de 6-bencilaminopurina (BAP) (0-10 mg L-1), ácido indol-3-acético (AIA) (0-0.5 mg L-1), pH 5.7 y 8, Ca2+ (13.2µM y 26.4 µM) y agar (7 y 10 g L-1). La mayor formación de brotes (2.9 brotes por explante) se obtuvo en medio MS con 2 mg L-1 de BAP combinado con AIA 0.5 mg L-1, 13.2 µM de Ca2+, pH 8 y 7 g L-1 de agar a los 120 días. Los brotes generados se transfirieron a medio MS con ácido 2,3,5 tri-iodobenzoico (TIBA) (0, 0.5, 1 y 2 mg L-1) para inducir la formación de raíz. El mayor enraizamiento (70.5%) se obtuvo en medio con 0.5 mg L-1 de TIBA. La sobrevivencia de las plantas fue del 58% a los 5 meses. Este es el primer reporte que describe la regeneración in vitro de E. parryi y constituye un avance importante para su propagación y conservación.

Climate and soil properties profoundly impact N mineralization (Nmin). Hence, there is a critical need to identify how physical-chemical-biological factors involved in organic matter decomposition influence globally reported predictive models. This paper reflects research focused on those factors considered relevant and used during the construction of Nmin models. The literature data found on factors affecting Nmin or N availability in soils published since 1990 was downloaded to a database in Access. Using different bivariate and multivariate statistical techniques, we compiled results of 785 statistical analyses presented by authors of 90 research articles that related Nmin and environmental factors, management strategies, and soil biological and physicochemical attributes. For organization purposes, we decided to group results according to the similarity of properties related to mineralization into environmental factors (18.6%), ecosystem/vegetation (14.52%), management (7.64%), soil physicochemical properties (34.65%), organic matter (16.05%), and microbiota (6.37%). The measurements of the response variables were 16.2% using N content in soil (as ammonium, nitrates, Organic N and Total N), and 83.88% represent N in the process of mineralization, including potentially mineralized N. As Nmin is the dependent variable, the results included 109 independent variables, of which 47.7% presented seemingly inconsistent results, which means different effects in Nmin. The difference in results was found to be related mostly to a difference in ecosystems or variable interactions. We conclude that acquiring a general prediction model for Nmin or constructing a specific equation for local conditions poses a limitation to optimizing N management for crop production. A more useful strategy is to generate a prediction model for Nmin, including significative soil and weather conditions, within a region and ecosystem; thus, the information can support soil and crop management decisions.

Quantification of chiltepin hot pepper (Capsicum annuum L. glabriusculum) phytochemicals provides a tool to evaluate the fruit quality and health impact. This study evaluates the phytochemical content and antioxidant activity of chiltepin from different locations of Sonora, Mexico, at two ripening stages (immature and mature). Seeds from Cumpas and Sahuaripa, were grown under greenhouse conditions and phenolic compounds, flavonoids, carotenoids, chlorophylls, and ascorbic acid were determined by spectrophotometric techniques. Capsaicinoids were determined by HPLC-DAD. The antioxidant activity was determined through DPPH and ABTS radical scavenging and by FRAP techniques. The origin of the seed influenced the antioxidant activity and phytochemical content. Samples from Cumpas, were superior in phytochemicals compared with Sahuaripa. Antioxidant activity and phytochemicals were higher in mature stage. Antioxidant activity correlates mainly with phenolic compounds and carotenoids. This study highlights that mature chiltepin pepper from Sonora could grow under controlled conditions develop bioactive compounds with antioxidant potential.

En semillas cosechadas por los agricultores se estudió la influencia en la sincronización de los diámetros de tallos en injertos comunes y recíprocos utilizando los tipos de chiles, jalapeño, chilaca y Cayene como injertos y el criollo de Morelos CM-334 como portainjerto. El grosor del tallo del CM 334 presentó mayor compatibilidad con el chile tipo jalapeño y con el tipo chilaca y fue muy distante con el grosor del tallo del tipo de chile Cayene. La formación de callo abundante entre la unión de los injertos ensayados mostró buena aptitud y af inidad locualpermitiólaconexiónfirmedelcambiumconelpatrón. Los porcentajes de supervivencia de los injertos fueron 90% con los chiles lo cual está dentro del rango aceptable a nivel comercial. El usar el CM 334 como un portainjerto resistente a P .capsici podría formar parte del manejo integrado para controlar la marchitez en estos tipos de chiles comerciales. El injerto reciproco puede ser usado para estudiar genes asociados con procesos de regulación de señales a distancia capaces de moverse de la raíz al brote como ramificaciones, floración, resistencia sistémica y respuestas a estrés abiótico.

Se evaluó el efecto de dos consorcios de hongos micorrícicos arbusculares (HMA) aislados de plantas de huizache (Acacia sp.) (HMA1) y de una asociación entre Larrea tridentata y Opuntia sp. (HMA2), nativas del desierto Chihuahuense, en los componentes del rendimiento y fitoquímicos en plantas de chile Jalapeño var. M crecidas bajo estrés salino en condiciones de invernadero. El diseño experimental constó de dos factores: HMA (HMA-, HMA1 y HMA2), y salinidad (testigo, 4 y 8 dS m-1) de una solución de NaCl y CaCl2, con nueve repeticiones por tratamiento. El número de esporas fue contabilizado y las plantas se inocularon con 40,000 esporas. La solución salina se aplicó 30 d después de la inoculación durante ocho semanas. El fósforo se aplicó con una solución de 44 mg L-1 de KH2PO4 a las plantas sin inocular y de 22 mg L-1 a las plantas inoculadas. La micorrización al final del experimento osciló entre 22 y 32 % en las plantas inoculadas. La salinidad afectó significativamente el desarrollo y el verdor de las plantas. Aunque el factor HMA tuvo un efecto negativo en el número de frutos, no se afectó el rendimiento en el peso fresco de los frutos. La salinidad tuvo un efecto negativo en el peso fresco de los frutos. Los HMA incrementaron significativamente el contenido de fósforo y ácido ascórbico, sin verse afectados el desarrollo y fisiología de la planta a pesar de la reducción en la cantidad de fósforo exógeno aplicado. La concentración de fósforo en los frutos fue mayor en las plantas inoculadas con HMA2. A mayor salinidad, los frutos tuvieron menor concentración de ácido ascórbico pero mayor concentración de fenoles totales en los frutos. El contenido de capsaicinoides no fue afectado por ninguno de los factores estudiados.

Malformation is the most important disease of mango in Mexico. It affects floral and vegetative shoots, and reduces fruit production. Although several species of Fusarium cause the disease worldwide, F. mexicanum is most important in Mexico. To better understand epidemiology of disease in Mexico, we studied mango nurseries as a source of infected planting material. In 2011, 2012 and 2014, 20 mango nurseries in the states of Colima (1 nursery), Jalisco (1 nursery), Guerrero (6 nurseries) and Michoacan (12 nurseries) were examined for floral and vegetative symptoms of the disease. Although malformed plants were not observed in Colima, Guerrero and Jalisco, malformed mango seedlings and grafted plants were observed in 10 commercial nurseries in Michoacan in 2011 and 2012. Thirty-three isolates from a total of 197 symptomatic plants were identified as F. mexicanum, based on morphological and genetic criteria. Analyses of partial sequences of the EF-1α and β-tubulin genes and mating type indicated that isolates of F. mexicanum from mango nurseries are mostly a single clonal population, identical to F. mexicanum isolates previously described from mango orchards in Michoacan. Thus, mango nurseries in Michoacan could be a significant source of inoculum when new mango orchards are established in the state. Efforts should be made to produce and utilize pathogen-free planting material during orchard establishment.

Phytophthora capsici causes significant damage to vegetable production in Mexico, but very little is known about the population structure or how populations survive and spread. The objective of the present study was to evaluate the genetic diversity of P. capsici isolates recovered from 1998–2014 in central and northern Mexico. Isolates (n = 81) were genotyped for 33 polymorphic single nucleotide polymorphism (SNP) loci using a targeted sequencing approach. There were a total of 72 unique genotypes and both the A1 and A2 mating types were common in both regions. Genetic analyses suggest clonal reproduction may play a more prominent role in the north, but the large proportion of unique genotypes and the finding of both mating types throughout both regions suggests outcrossing and sexual recombination likely play an important role in the overall epidemiology. Further studies with finer scale sampling at single locations over multiple years will be valuable.

Black grama (Bouteloua eriopoda) and fourwing saltbush (Atriplex canescens) are important grass and shrub species in arid rangelands of the northern Chihuahuan Desert. They are naturally colonized by dark septate endophytic fungi that cannot be eliminated by seed disinfestation. Plants were regenerated from both species and appeared to be fungus-free in axenic cultures. Analysis of callus and regenerated plants of both species using dual staining with light and scanning electron microscopy revealed fungal endophytes intrinsically associated with cells, roots and leaves of regenerated plants that are also associated with native plants. Fungal layers and biofilms prevent direct exposure of callus, root or leaf tissues to the external environment. Micropropagation is a valuable tool for identifying key fungal endophytes that enhance drought tolerance in native desert plants.

Alginates are naturally occurring components of organic matter in natural soil whose effects on nanoparticle (NP) toxicity to plants is not well understood. In the present study, corn plants were grown for one month in soil spiked with 400 mg/kg CeO2 NPs with various alginate concentrations. After one month of growth in the NPs impacted soil, plants were harvested and analyzed for Ce and mineral element concentrations. Chlorophyll concentration and heat shock protein 70, used as biomarkers for oxidative stress, were also evaluated. Results showed that, compared to CeO2 NPs treatment, alginate at 10, 50, and 100 mg/kg increased Ce concentration in roots by approximately 46%, 38%, and 29% and by 115%, 45%, and 56% in shoots, respectively. CeO2 NPs without alginate increased Mn accumulation in roots by 34% compared to control. CeO2 NPs with low and medium alginate increased Mn by ca. 92% respect to NPs without alginate and by ca. 155% respect to control. CeO2 NPs without/with alginate significantly increased accumulation of Fe and Al in roots. In addition, alginate at 50 mg/kg increased Zn accumulation in roots by 52% compared to control. In shoots, K increased at all NP treatments but the accumulation of other elements was not affected. Alginate enlarged the impact of CeO2 NPs to corn plants by reducing chlorophyll a content and triggering overexpression of heat shock protein 70.

The effects of nCeO2 on food quality are not well known yet. This research was performed to determine the impact of nCeO2 on radish (Raphanus sativus L.). Plants were cultivated to full maturity in potting soil treated with nCeO2 at concentrations of 0, 62.5, 125, 250, and 500 mg/kg. Germination, growth, photosynthesis, ionome, and antioxidants were evaluated at different growth stages. Results showed that at 500 mg/kg, nCeO2 significantly retarded seed germination but did not reduce the number of germinated seeds. None of the treatments affected gas exchange, photosynthesis, growth, phenols, flavonoids, and nutrients' accumulation in tubers and leaves of adult plants. However, tubers' antioxidant capacity, expressed as FRAP, ABTS•− and DPPH, increased by 30%, 32%, and 85%, respectively, in plants treated with 250 mg nCeO2 kg−1 soil. In addition, cerium accumulation in tubers of plants treated with 250 and 500 mg/kg reached 72 and 142 mg/kg d wt, respectively. This suggests that nCeO2 could improve the radical scavenging potency of radish but it might introduce nCeO2 into the food chain with unknown consequences.

Green and etiolated shoot apices of foxtail millet (Setaria italica L.) cv. Nese 2A were cultured on Murashige and Skoog medium with four concentrations of 2,4-dichlorophenoxyacetic acid or 2,4,5-trichlorophenoxyacetic acid. In all treatments, embryogenic calli capable of plant regeneration were induced after ten weeks in culture. Calli induced on 2 mg l-1 of 2,4-d from green apices gave a higher rate of plant regeneration in comparison with etiolated apices on the other treatments. Plant regeneration was obtained from one year-old cultures. Regenerated plants were successfully established in soil, reached maturity and produced seeds.