Formación de embriones somáticos en Persea americana Mill var. Catalina a partir de embriones cigóticos inmaduros

The establishment of embryogenic culture of avocado have been achieved in different genotypes, usually the immature zygotic embryos are the initial explants and the process has been described in several variety. In the present paper the induction of the somatic embryogenesis in avocado (Catalina variety) from zygotic embryos is proposed. Zygotic embryos taken from unripe fruits were used as explants . The fruits were divided into five groups according to their size. The embryos were cultured in a medium containing 4-amino-3,5,6 trichlorpicolinic acid (Picloram) in concentrations of 0.1, 0.4, and 0.6 uM. The culture medium used for the induction of the somatic embryogenesis consisted of: Macro B5, Micro MS, thiamine (0.8 mg.l-1), myo-inositol (100 mg.l-1), sucrose (30g.l-1) and pH 5.7. The number of zygotic embryos with opened cotyledonal leaves was evaluated starting from the third day of culture. It was also evaluated the number of fenolized zygotic embryos at the third week of culture and the presence of somatic embryos five weeks after the culture initiation. The formation of somatic embryos was achieved in all the treatments. The highest number of explants that formed somatic embryos was achieved when a concentration of 0.6 uM of Picloram was used and the second group of size (0.71 x 0.65 mm) observing significant differences between the different groups of fruit size.Keywords: avocado, cotyledonal leafs, somatic embryo,El establecimiento de cultivos embriogénicos de aguacate se ha logrado en diferentes genotipos, los embriones cigóticos inmaduros son los explantes iniciales más empleados y se ha descrito el proceso en varios cultivares de interés económico. El presente trabajo aborda la inducción y formación de embriones somáticos en el aguacatero cv. Catalina, al utilizar como explantes iniciales embriones cigóticos inmaduros. Los frutos inmaduros fueron agrupados en cinco rangos de tamaño para la extracción de los embriones cigóticos. Estos posteriormente se sembraron en medios de cultivo que contenían 4-amino-3,5,6- ácido tricloropicolínico (Picloram) en concentraciones de 0.1, 0.4 y 0.6 µM. El medio de cultivo utilizado para la inducción de la embriogénesis somática, consistió en Macro B5, Micro MS, tiamina (0.8 mg.l-1), mio-inositol (100 mg.l-1), sacarosa (30 g. l-1) y pH 5.7. Se evaluó el número de embriones cigóticos con hojas cotiledonares abiertas a partir del tercer día de cultivo, el número de embriones fenolizados a la tercera semana de cultivo y la presencia de embriones somáticos, a las cinco semanas de cultivo. Se logró la formación de embriones somáticos en todos los tratamientos estudiados. El mayor número de explantes que formaron embriones somáticos se obtuvo cuando se utilizó la concentración de 0.6 øM de Picloram, con un rango de tamaño del fruto inmaduro de 0.71 x 0.65 mm (rango 2). Se apreciaron diferencias significativas entre los grupos de tamaño de fruto.Palabras clave: aguacatero, embrión somático, hojas cotiledonares, piclora

Efectos de la posición de plantación y la aplicación de Azospirillum brasilense en el crecimiento inicial de la yuca (Manihot esculenta crantz).

This work aimed to evaluate the effect of the strick planting position and Azospirillum brasilense application on the initial growth of cassava. The assay was carried out following a completely randomized experimental design, with factorial arrangement (planting positions [horizontal (HP) and vertical (PV)] and the A. brasilense [with (+Azos) and without (-Azos)]). The sprouting percentage (SP) was evaluated from 11 to 35 days after planting (DAP). After 30 DAP, the following variables were evaluated: sprouts number (SN), sprouts height (SH), number of leaflets (NL), length of leaflets (LL), and vegetative vigor (VV). Cassava plants positioning significantly influenced the initial growth. PV promotes a greater sprouting, 63% in 17 DAP, over the PH which was only 3% of the visible shoots during the same period. Here we show for the first time that PV promoted the highest values combined with -Azos in the variables SH (an increase of 17%) and VV (an increase of 61%). The PH, in combination with +Azos, stimulated the NL in 20%. The sub-division into three VV groups allowed identify the existence of differences among the treatments which were not seen in an independent ANOVA being VV an important variable for the initial growth evaluation in cassava.El trabajo tuvo como objetivo evaluar el efecto de la posición del propágulo de yuca y la aplicación de Azospirillum brasilense en el desarrollo inicial de la plántula. El experimento se realizó siguiendo un diseño completamente aleatorizado, con arreglo factorial (posición del propágulo [horizontal (PH) y vertical (PV)] y A. Brasilense [con (+Azos) y sin (-Azos)]. El porcentaje de brotación (PB) se evaluó de 11 a 35 días después de la siembra (DAP). Luego de 30 DAP, se evaluaron las siguientes variables: número de brotes (NB), altura de brotes (AB), número de folíolos (NF), longitud de folíolos (LF) y vigor vegetal (VV). La posición de las plantas de yuca influyó significativamente en el crecimiento inicial. La PV promueve una mayor brotación, 63% en 17 DAP, sobre la PH que fue del orden de 3% de los brotes visibles en el mismo período. En el trabajo se muestra que la PV promovió los valores más altos combinados con -Azos en las variables AB (aumento de 17%) y VV (aumento de 61%). La PH, en combinación con +Azos, estimuló el NF en 20%. La subdivisión en tres grupos de VV permitió identificar de forma visual diferencias entre tratamientos, que no se observaron en un ANOVA independiente. La VV es una variable importante para la evaluación del desarrollo inicial de la yuca

First report of Sinomonas halotolerans from Parkinsonia aculeata rhizosphere

There are only 10 validly characterized species in the genus Sinomonas, all of which are isolated from various soil types in Asia and have been reported as a result of useful biotechnological applications. Here we described the first report of the species Sinomonas halotolerans isolated from rhizospheric soil samples of Parkinsonia aculeata based on materials collected from the Sonoran Desert, Mexico. Parkinsonia aculeata is an indigenous species that has weathered salinity, drought, and extremely high temperatures in the semiarid parts of Mexico and contributes significantly to the functionality of these ecosystems through considerable rates of vegetation. Materials were collected three times, in February, March, and August 2022 in 2 locations: Bahia de Lobos and Tesopaco, affected by two abiotic stress conditions: salinity and drought respectively. During the investigation, the strains BA8A, BA10B, and TA1 were isolated from both locations, they were identified using microbiological and molecular techniques. Based on the 16S rRNA gene sequences, the three strains were identified as Sinomonas halotolerans (99.9% sequence similarity). As the genus Sinomonas is still poorly known in America, our study may help to improve this situation and S. halotolerans might be considered a potential species to develop novel biotechnological applications with the aim to cope with the adverse effects of salinity and drought in soil

Formation of somatic embryos in Persea americana Mill var Catalina from immature zygotic embryos.

The establishment of embryogenic culture of avocado have been achieved in different genotypes, usually the immature zygotic embryos are the initial explants and the process has been described in several variety. In the present paper the induction of the somatic embryogenesis in avocado (Catalina variety) from zygotic embryos is proposed. Zygotic embryos taken from unripe fruits were used as explants . The fruits were divided into five groups according to their size. The embryos were cultured in a medium containing 4-amino-3,5,6 trichlorpicolinic acid (Picloram) in concentrations of 0.1, 0.4, and 0.6 uM. The culture medium used for the induction of the somatic embryogenesis consisted of: Macro B5, Micro MS, thiamine (0.8 mg.l-1), myo-inositol (100 mg.l-1), sucrose (30g.l-1) and pH 5.7. The number of zygotic embryos with opened cotyledonal leaves was evaluated starting from the third day of culture. It was also evaluated the number of fenolized zygotic embryos at the third week of culture and the presence of somatic embryos five weeks after the culture initiation. The formation of somatic embryos was achieved in all the treatments. The highest number of explants that formed somatic embryos was achieved when a concentration of 0.6 uM of Picloram was used and the second group of size (0.71 x 0.65 mm) observing significant differences between the different groups of fruit size. Keywords: avocado, cotyledonal leafs, somatic embryo

Initial response of phenology and yield components of wheat (Triticum durum L., CIRNO C2008) under experimental warming field conditions in the Yaqui Valley

"This work evaluates the experimental warming effects on phenology and grain yield components of wheat in the Yaqui Valley, Sonora, México, using CIRNO C2008 variety from Triticum durum L., as a model during the cropping cycle of 2016–2017 (December to April). Infrared radiators were deployed to induce experimental warming by 2 °C above ambient crop canopy temperature, in a temperature free-air controlled enhancement system. Temperature was controlled by infrared temperature sensors placed in eight plots which covered a circle of r = 1.5 m starting five days after germination until harvest. The warming treatment caused a reduction of phenophases occurrence starting at the stem extension phenophase. Such phenological responses generated a significant biological cycle reduction of 14 days. Despite this delay, CIRNO C2008 completed its biological cycle adequately. However, plant height under the warming treatment was reduced significantly and differences were particularly observed at the final phenophases of the vegetative cycle. Plant height correlated negatively with spikes length, spikes mass, and number of filled grains. Warming also reduced grain yield in 33%. The warming treatment caused a stress intensity (SI = 1-yield warming/yield control) of 39.4% and 33.2% in biomass and grain yield, respectively. The differences in stress intensities between biomass and grain yield were based on plant height reduction. Grain mass was not affected, demonstrating the crop capability for remobilization and adequate distribution of elaborated substances for the spikes under warming conditions.

Water regime and osmotic adjustment under warming conditions on wheat in the Yaqui Valley, Mexico

An experiment was carried out to evaluate the effect of increased temperature on roots and leaf water and osmotic potential, osmotic adjustment (OA) and transpiration on Triticum durum L. (CIRNO C2008 variety) during growth (seedling growth), tillering and heading phenophases. Wheat was sown under field conditions at the Experimental Technology Transfer Center (CETT-910), as a representative wheat crop area from the Yaqui Valley, Sonora México. Thermal radiators were placed at 1.20 m from the crop canopy. Treatments included warmed plots (2 °C) and ambient canopy temperature with five replicates. Temperature treatment was controlled using a (proportional, integrative, derivative) feedback control system on plots covering a circular area of r = 1.5 m. Results indicated a significant decrease in the osmotic potential of roots and leaves for the warmed plots. Water potential, under warming treatment, also experienced a significant reduction and a potential gradient was observed in both, roots and leaves, while the phenophases were delayed. Such results demonstrate that, under warmer conditions, plants increase water absorption for cooling. Hence, transpiration experienced a significant increase under warming in all phenophases that was related to the low root and leaf water potential. CIRNO C2008 also experienced OA in all phenophases with glycine betaine as the osmolyte with major contribution

Efecto de la salinidad en callos de variedades de trigo durante el cultivo in vitro

Se estudió el efecto de la salinidad en el grado de tolerancia al estrés y la efectividad de la radioinducción de mutaciones en callos de tres variedades de trigo harinero durante el cultivo in vitro. El estudio se desarrolló en el centro de Ingeniería Genética Biotecnología (CIGB) de la Habana, Cuba en el período comprendido entre noviembre de 2015 a febrero de 2016 en un programa de mejora genética para tolerancia a estrés salino en fase de cultivo in vitro. Se evaluaron las variables permeabilidad de las membranas celulares, actividad peroxidasa, concentración de proteínas solubles y síntesis de ácido abscísico a las 24 h, 30 días y 70 días de exposición de los callos a los tratamientos, los cuales consistieron en conductividades eléctricas (CE) de 0.02, 5 , 7, 9 dS m-1 en el medio de cultivo. Se observó a las 24 h, un incremento de la PMC como efecto estimulante inicial de la salinidad, valores que disminuyeron conforme se incrementó la CE y el tiempo de exposición al estrés. La actividad peroxidasa se incrementó hasta los 7 dS m-1 en las tres variedades pero la tendencia fue a mantenerse o disminuir cuando se incrementó CE. Respuesta similar mostraron las proteínas solubles totales. La concentración de ABA aumentó en más de 25 unidades en las variedades quedando descartada la hipótesis de su síntesis a partir de pigmentos fotosintéticos y protectores. La evaluación realizada demostró el efecto positivo de la radioinducción en la tolerancia del trigo al estrés salinoThe effect of salinity on the stress tolerance degree and the radioinduction effectiveness of callus mutations of three common wheat varieties during in vitro culture was studied. The researcg was developed at the Center for Genetic Engineering Biotechnology (CIGB) of Havana, Cuba in the period from November 2015 to February 2016 in a genetic improvement program for tolerance to salt stress in in vitro culture phase. The variables cell permeability, peroxidase activity, soluble protein concentration and abscisic acid synthesis were evaluated at 24 h, 30 days and 70 days of callus exposure to treatments, which consisted of electrical conductivities (EC) of 0.02, 5, 7, 9 dS m-1 in the culture medium. An increase in PMC was observed at 24 h as the initial salinity stimulating effect, values that decreased as the EC and the time of exposure to stress increased. Peroxidase activity increased to 7 dS m-1 in all three varieties but the trend was to be maintained or decreased when CE increased. Similar response showed total soluble proteins. The concentration of ABA increased by more than 25 units in the varieties and the hypothesis of its synthesis was ruled out from photosynthetic and protective pigments.The evaluation showed the positive effect of radioinduction on wheat tolerance to saline stress

Parkinsonia aculeata L.: Fitotoxicidade em tomate

Parkinsonia aculeata L. (palo verde) it is native to semidesert region and seasonally dry tropical forests. A more detailed study of the biochemical composition of its organs could offer information for its use for pest and disease biocontrol in species of agricultural and economic interest. This research aimed to determine the content of polyphenols and flavonoids in hydroalcoholic extracts obtained from the stems and leaves of P. aculeata and its phytotoxicity in tomato seedlings applied at the early stages of growth. The extracts were applied at 15, 25 and 35 days after emergence (DAE). The highest content of polyphenols and flavonoids was obtained in the leaves, and the polyphenol concentration exceeded that of flavonoids. The hydroalcoholic extracts, of both stems and leaves, presented level 5 phytotoxicity in tomato plants at 15 DAE. However, from 25 DAE, there was no phytotoxicity. At 35 DAE, there was only phytotoxicity when the volume of both organs was 5 mL Plant-1. There was a significant interaction between organ and volumes factors. The study shows that leaf and stem extracts can be used for fusarium wilt biocontrol without causing phytotoxicity in tomato plants from 25 days, using volumes between 1 and 3 mL plant-1.Parkinsonia aculeata L. (palo verde) es originaria de regiones semidesérticas y bosques tropicales estacionalmente secos, aunque se distribuye en varias regiones del mundo. Entre las principales características de esta especie se encuentran el tallo verde, plantas reducidas, vegetales moniliformes, número mínimo de plagas y enfermedades que la afectan. Un estudio más detallado de la composición bioquímica de sus órganos podría ofrecer información para su uso en el biocontrol de plagas y enfermedades en especies agrícolas de interés económico. El presente estudio tuvo como objetivo determinar los contenidos de polifenoles y flavonoides en extractos hidroalcohólicos de tallos y plantas de P. aculeata y la fitotoxicidad en plántulas de tomate, aplicado en etapas tempranas de desarrollo. Los extractos se aplicaron a los 15, 25 y 35 días después de la emergencia (DPE). El mayor contenido de polifenoles y flavonoides se obtiene hoy en día y la concentración de polifenoles supera a la de flavonoides. Los extractos hidroalcohólicos, tanto de tallo como de hoy, presentan un nivel 5 de fitotoxicidad en plantas de tomate, sin embargo, a partir del 25 DPE no existe fitotoxicidad. A los 35 DPE solo existió fitotoxicidad cuando se aplicó el volumen de 5 mL de Plant-1 de ambos órganos. Hubo una interacción significativa entre el órgano y las fuentes de variación de volumen. El estudio demuestra que los extractos de plantas y tallos pueden ser utilizados para el biocontrol de fusariosis sin causar fitotoxicidad en plantas de tomate a partir de los 25 días, utilizando dosis entre 1 y 3 mL planta-1.Parkinsonia aculeata L. (palo verde) es originaria de región semidesértica y bosques tropicales estacionalmente secos, aunque se distribuye en varias regiones del mundo. Entre las principales características de esta especie es el tallo verde, hojas reducidas, legumes moniliformes, mínima cantidad de plagas y enfermedades que la afectan. Un estudio más detallado de la composición bioquímica de sus órganos pudiera ofrecer información para su uso en el biocontrol de plagas y enfermedades en especies agrícolas de interés económico. El presente estudio tuvo como objetivo determinar los contenidos de polifenoles y flavonoides en extractos hidroalcohólicos de tallos y hojas de P. aculeata y la fitotoxicidad en plántulas de tomate, aplicados en estadios iniciales del desarrollo. Los extractos fueron aplicados a los 15, 25 y 35 días posteriores a la emergencia (DPE). El mayor contenido de polifenoles y de flavonoides se obtuvo en las hojas y la concentración de polifenoles superó a la de los flavonoides. Los extractos hidroalcohólicos, tanto de tallos como de hojas presentaron fitotoxicidad de nivel 5 en las plantas de tomate, sin embargo, a partir de los 25 DPE no existió fitotoxicidad. A los 35 DPE solo existió fitotoxicidad cuando se aplicó el volumen de 5 mL Planta-1 de ambos órganos. Existió interacción significativa entre las fuentes de variación órganos y volumen. El estudio demuestra que se pueden emplear extractos de hojas y tallos para el biocontrol de fusariosis sin causar fitotoxicidad en plantas de tomate a partir de los 25 días, empleando dosis entre 1 y 3 mL planta-1

Contribution of QuitoMax® to the hormonal and enzymatic metabolism in tomato under saline stress

ABSTRACT Salinity stress severely restricts plant nutrition and hinders biochemical and physiological processes crucial for growth. In several crop systems bioactive products which confer growth promotion, are applied as a sustainable alternative for contributing to food security. The aim of this work was to evaluate the biochemical contribution of QuitoMax® to hormonal and enzymatic metabolism in tomato under saline stress. Three treatments were applied: saline without QuitoMax®, nonsaline + QuitoMax® and saline + QuitoMax®. A tolerant (Amalia) and a susceptible (Claudia) tomato variety were used as experimental models. The normalized difference vegetation index (NDVI) was measured as a morphological variable, and peroxidase (POD), glutamine synthetase (GS) and nitrate reductase (NR) enzyme activities were determined. Gibberellic (GA) and abscisic acid (ABA) concentrations were also determined. Due to the effects of QuitoMax®, the plants maintained high NDVI values even under saline conditions. A decrease in POD and GS activity and an increase in NR activity were also found. The GA concentration in the leaves was higher in the tolerant variety when QuitoMax® was applied than in the saline treatment but lower in the susceptible variety. The opposite behavior was found when the ABA concentration was quantified. This study demonstrates the protective action of QuitoMax® under salinity stress on tomato crops in both tolerant and susceptible varieties. In crux, QuitoMax® can be opted as a shotgun approach to tackle salinity in tomato