Search

Plants rhizosphere and bacterial communities' association offer great advantages for its adaptation to adverse conditions in desert ecosystems. In the Sonoran Desert, Mexico, there is low diversity of species due to the significant incidence of high salinity, drought and extreme temperatures. However, Parkinsonia aculeata L. is an endemic species adapted to these adverse environmental conditions. Here, we aimed to isolate and molecularly characterize bacterial isolates associated with P. aculeata rhizosphere grown in saline soils (BL site) and drought (RT site). A total of thirty-three bacteria isolates from the P. aculeata rhizosphere were identified by 16S rDNA sequencing finding members of the genera: Bacillus, Enterobacter, Priestia, Sinomonas, Micrococcus, Kocuria, Staphylococcus, Streptomyces, Arthrobacter and Peribacillus. Priestia followed by Bacillus and Staphylococcus genus showed the major abundance percentages in both sites. The isolated strains were previously reported to exhibit plant beneficial traits, promote plant growth preserve the soil, provide an opportunity for the development of environmentally friendly alternatives for agriculture and to be used as experimental models to study drought/salt mitigation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Maize breeding has evolved increasingly with the emergence of new scientific technologies, mainly hybridization. This technique allows new genetic combinations to be obtained in specific areas where some genotypes have desirable characteristics. By crossing them, hybrids with better morphological, physiological and agronomic performance are obtained. Based on the above, the objective of this research was to evaluate the morphological and reproductive variables, final plant height (FPH), ear height (EH), number of leaves above (NLAE) and below (NLBE) the ear, grain depth (GD), number of rows per ear (NRE), number of grains per row (NGE), volumetric weight (VW), and grain yield (Y), in four simple maize hybrids, two white-grain hybrids (WG1 and WG2), and two yellow-grain hybrids (YG1 and YG2). The crop was established in the period December-May 2023. These hybrids come from a dialelic of homozygous lines, carried out at the Tecnológico Nacional de México, campus Valle del Yaqui. Significant differences were found in all the variables evaluated. The GBI hybrid showed the highest FPH (264 cm), EF (159 cm) and NLAE (9.8). Similarly, this hybrid had the highest GD (2.1 mm) and NRE (16). The YG1 hybrid showed a higher number of grains per row (32) and volumetric weight (389 g), without differences from WG1. These two hybrids (WG1 and YG1) had the highest grain yield (11.8 t ha-1). There was a positive and significant correlation between several variables, with the highest correlation between FPH and NLAE and between the variables NGE and Y. [ABSTRACT FROM AUTHOR]

Se estableció un experimento en condiciones de campo en el Valle del Yaqui, Sonora, México, que consistió en elevar la temperatura del trigo en 2 °C por encima de la temperatura ambiente del dosel durante la fenología del cultivo y determinar su efecto en los contenidos de proteínas (PST) y carbohidratos solubles totales (CTS) en tallos y en grano, la tasa de movilización de los carbohidratos (TMC) del tallo, y el índice de vegetación de diferencia normalizada (NDVI). Se utilizó como modelo experimental la variedad de trigo cristalino CIRNO C2008. El contenido de PST, por efecto del calor disminuyó significativamente en la fenofase de espigamiento respecto al tratamiento de Control, lo que denota una senescencia temprana. El contenido CST en el tallo fue mayor en el tratamiento de Calor cuando se determinó 10 días después de la floración. En la maduración no existieron diferencias significativas. El calor impuesto no afectó la TMC. En el grano, el calor no afectó el contenido de PST, pero sí se incrementó el contenido de CST. El NDVI, debido al calor, disminuyó a partir de la fenofase de elongación del tallo hasta la maduración. El máximo valor de NDVI ocurrió, en los tratamientos en la floración, demostrando tolerancia de la variedad al calor para la ocurrencia de esta fenofase. Tales resultados sugieren la factibilidad del uso de CIRNO C2008, como posible progenitor para programas de mejora genética ante el estrés térmico. [ABSTRACT FROM AUTHOR]

Due to the importance of the correct selection of progenitors for an effective genetic improvement in highly productive wheat regions such as the state of Sonora, which contributes 50 % of the wheat in Mexico, we conducted a study of morphoagronomic variables of the crystalline wheat CIRNO C2008 variety. The objective was to determine the genetic stability index of the grain yield components in the Valle del Yaqui and Valle del Mayo, during the sowing seasons of 2007-2015. In addition, physiological and agronomic traits were evaluated in the 2015-16 cycle in an area established in CETT-910, as a representative site of the Valle del Yaqui, which were compared with the varietal descriptor and correlated with grain yield to contribute to its physioagronomic characterization. The experimental design was completely randomized and data were taken from different sites of the valleys mentioned in the state of Sonora. The highest grain yield was obtained in the Valle del Yaqui. The variables of plant height and spike length were the components of the yield with the highest index of genetic stability. The variety phenophases occurred properly without affecting the biological cycle. The grain yield in the CETT-910, in the 2015-2016 cycle, was higher than that obtained by the varietal descriptor as a result of good nutritional status and high photosynthesis. The results show that CIRNO C2008 maintains genetic stability of the yield components after eight years of being released for agricultural production in the Valle del Yaqui and Valle del Mayo. [ABSTRACT FROM AUTHOR]

Heat stress in plants trigger responses that affect phenology, physiology, metabolism, and in some cases modify genetic expression, causing variations on agronomic and industrial yield in crops such as wheat. Although not all species and varieties show similar responses to heat stress, monitoring the response of the available germplasm through physiological, biochemical and molecular indicators will allow to identify possible progenitors for genetic improvement, and to recommend tolerant genotypes to regionalize varieties. Given the imminence of climate change that includes significant increases of temperature in several regions where wheat is grown, it is necessary to assess its effects. An important step in this direction is to know the actual state of current research related to the heat stress response. In the present article some heat stress effects on wheat are described due to its importance for human and animal food, and its contributions to the international economy. [ABSTRACT FROM AUTHOR]

With the aim to evaluate the salt stress tolerance of 12 cowpea (Vigna unguiculata L. Walp.) varieties by using some variables relative to nodule formation, aerial dry mass and its nitrogen content, two simultaneous experiences in saline and not saline soils were carried out. A completely randomize block design with three repetitions was used in both experiences. The aerial and roots dry mass, number of nodules per plants, number of effective nodules, nodules dry mass and nitrogen content in aerial mass were evaluated at 40 days after sowing. Using the measured results the tolerance index to salinity in all varieties was calculated, which were classified using a Cluster analysis of Complete Linkage, based on Euclidian distance. The results evidenced the affectation of all varieties sowed on saline soil when the nodules number, its dry mass, as well as the aerial dry mass and its nitrogen content were evaluated, but the main differences among genotypes, and the tendency to saline tolerance were found by using the cluster analysis, through which varieties were classified in two different groups. Into the first group, eight genotypes with marked tolerance characteristic to saline stress were located, while the others four varieties were categorized as susceptible, being situated into the second group. [ABSTRACT FROM AUTHOR]

Biocontrol, an alternative to chemical control against plant pathogens, may also improve plant health and enhance fruit yield. Tomato production in open fields or greenhouses is constrained by the pathogens Fusarium oxysporum f. sp. lycopersici race 3 (Fol R3) and F. oxysporum f. sp. radicis-lycopersici (Forl). In this work, we studied the biocontrol effect of the antagonistic bacteria Acinetobacter calcoaceticus AcDB3, Bacillus thuringiensis BtMB9, B. subtilis BsTA16, and B. amyloliquefaciens BaMA26 in field trials with four tomato hybrids over two consecutive growing seasons (2019–2020 and 2020–2021). The effect of these bacteria on plant growth was also evaluated. The presence of F. oxysporum in field soil and/or infected plants was confirmed microbiologically. All four bacterial strains significantly suppressed the severity of Fusarium crown and root rot of tomato (FCRRT) and Fusarium wilt symptoms, as well as increased tomato yield under field conditions. Among the four strains, B. subtilis BsTA16 showed the highest reduction in symptoms of Fusarium wilt (68%) and FCRRT (74%). To the best of our knowledge, this is the first report of biological control agents (BCAs) exerting antagonistic activity against both FCRRT caused by Forl and Fusarium wilt caused by Fol in tomato under field conditions. [ABSTRACT FROM AUTHOR]