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

Physiological response of chickpea (Cicer arietinum L.) in symbiosis with arbuscular mycorrhizal fungi under salinity conditions

Objective: The effect of salinity by NaCl based on physiological variables of chickpea plants was evaluated with the use of native strains of arbuscular mycorrhizal fungi Glomus cubensis and Rizoglomus irregulare during the pre-flowering phenophase. Design/methodology/approach: The research was carried out under controlled environmental conditions, using as an experimental model the chickpea variety N-29, obtained at INIFAT, Cuba. The treatments consist of the combination of three salinity levels: 25, 50 and 75 mM of NaCl and the respective control (Source of variation A) and two strains of AMFs (source of variation B) for a total of 12 treatments with six repetitions. Treatments were distributed under a completely randomized experimental design. The variables evaluated were: number of green and dry leaves, biomass by organs (leaves, stem, root), net assimilation rate (TAN), relative growth rate (TCR) and leaf area ratio (RAF). Results: Green leaves, TAN and leaf and root biomass were the variables with the highest response in the 50 mM NaCl + R. irregulare treatment, with an average increase of 15% compared to the rest of the treatments. Limitations on study/implications: There is a decrease in the variables evaluated due to the salinity effect, however, chickpea plants subjected to 50 mM NaCl inoculated with R. irregulare were less affected by saline stress. Findings/conclusions: It was also found that the R. irregulare strain contributed more than G. cubense to mitigating the adverse effects of the salinity factor.Objective. Evaluate the effect of salinity due to NaCl on physiological variables of chickpea plants using native strains of arbuscular mycorrhizal fungi (AMF) Glomus cubensis and Rhizoglomus irregulare during the pre-flowering stage. Design/methodology/approach. The research was carried out under controlled weather conditions using the chickpea variety N-29 as an experimental model. The treatments consisted on the combination of four salinity levels: 0, 25, 50 and 75 mM NaCl (variation source A) and AMF (variation source B) in three levels. In total there were 12 treatments with six repetitions, which were distributed in a completely randomized experimental design. The evaluated variables were number of green and dry leaves, dry biomass per organ (leaves, root and stem), net assimilation rate (NAR), relative growth rate (RGR) and leaf area ratio (LAR). Results. The green leaves, the NAR and the dry biomass from roots and leaves, were the variables with the greatest response in the 50 mM NaCl + R. irregulare treatment, with an average increase of 15% with respect to the rest of the treatments. Limitations/implications. A decrease on the evaluated variables was observed due to the salinity effect; however, chickpea plants subjected to NaCl 50 mM inoculated with R. irregulare were less affected by salt stress. Findings/conclusions. The R. irregulare strain was found to contribute more than the G. cubensis to the mitigation of the adverse effects from the salinity factor

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

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

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

Salinity effects on water potential and the normalized difference vegetation index in four species of a saline semi-arid ecosystem

This study was carried out during January 2020–December 2020 in a semi-desert ecosystem in southern Sonora, Mexico, to determine the annual and daily variations in water potential and the normalized difference vegetation index (NDVI) of Bursera fagaroides Engl., Monogr. Phan., Parkinsonia aculeata L., Sp. Pl.; Prosopis laevigata (Humb. & Bonpl. ex Willd.), and Atriplex canescens (Pursh) Nutt. Soil electrical conductivity, cation content, and physical characteristics were determined at two depths, and water potential (ψ) was measured in roots, stems, and leaves. The daily leaf ψ was measured every 15 days each month to determine the duration of stress (hours) and the stress intensity (SI). The electrical conductivity determinations classified the soil in the experimental area as strongly saline. A significant difference was noted in electrical conductivity between soil depths. The four studied species showed significant gradients of ψ in their organs. In this soil, all four species remained in a stressed condition for approximately 11 h per day. The mean SI was 27%, and B. fagaroides Engl., Monogr. Phan. showed the lowest value. The four species showed increased NDVI values during the rainy months, with P. laevigata (Humb. & Bonpl. ex Willd.) and Parkinsonia aculeata L., Sp. Pl. showing the highest values. The capacity for ψ decrease under saline conditions identified A. canescens (Pursh) Nutt., B. fagaroides Engl., Monogr. Phan. and P. aculeata L., Sp. Pl. as practical and feasible alternatives for establishment in saline soils in southern Sonora for purposes of soil recovery and reforestation