EVALUATION OF HYBRIDS FROM SIMPLE CROSSES USING MAIZE ELITE LANDRACES WITH FORAGE OUTSTANDING CHARACTERISTICS FOR A MEXICAN ARID LAND

The Comarca Lagunera region is the most important area of maize forage in México. In this region; which is shared by the Mexican States of Coahuila and Durango, are used a great amount of hybrids and varieties of maize imported from other countries. Generally, these genotypes are not completely adapted to the soil and/or climatic conditions of the region. These antecedents lead scientists to pursuit for genotypes with the best adaptation to such conditions. The present investigation was carried out with the aim to find the best hybrids from the crosses of ten self-pollinating landraces following a diallel mating design. The landraces were obtained from different institutions: a) the International Maize and Wheat Improvement Center (CIMMYT), b) the “Antonio Narro†Agrarian Autonomist University (UAAAN), and c) the National Institute of Agriculture, Forestry and Livestock Research (INIFAP). The following variables were evaluated from the hybrids: whole plant fresh matter yield (FMY), whole plant dry matter (DMY), fresh fruit yield (FFY) fresh stem yield (FSY), and fresh foliar yield (FLY). All variables reported as t ha-1. The Griffing statistical analysis was used to determine the general combining ability (GCA), and the specific combining ability (SCA). The highest values of GCA were obtained for the landraces M7, M8, and M9. The hybrids with highest SCA were: M5xM7, M2xM7, M6x10, M4xM8, M5xM8, M8xM10, M2xM5, M1xM10 and M6xM9. Two of these hybrids (M5xM7 and M2xM7) also showed the highest values for FMY and DMY. In conclusion, there is enough variability on FMY and DMY to believe on the possibility to find the most appropriate hybrid for the targeted region, and also to extend the breeding program to other arid lands in Méxic

Fourier transform mid infrared spectroscopy applications for monitoring the structural plasticity of plant cell walls

Fourier Transform Mid-Infrared (FT-MIR) spectroscopy has been extensively used as a potent, fast and non-destructive procedure for analyzing cell wall architectures, with the capacity to provide abundant information about their polymers, functional groups, and in muro entanglement. In conjunction with multivariate analyses, this method has proved to be a valuable tool for tracking alterations in cell walls. The present review examines recent progress in the use of FT-MIR spectroscopy to monitor cell wall changes occurring in muro as a result of various factors, such as growth and development processes, genetic modifications, exposition or habituation to cellulose biosynthesis inhibitors and responses to other abiotic or biotic stresses, as well as its biotechnological applications

MANEJO DE PLAGAS EN LA PRODUCCIÓN DE HORTALIZAS ORGANICAS

Los alimentos orgánicos son producidos mediante prácticas que promueven la fertilidad del suelo y la diversidad biológica, y excluyen todos aquellos productos químicos que se usan en la agricultura convencional. En regiones aisladas este tipo de producción no presenta serios inconvenientes, ya que el mismo sistema protege los cultivos de altos niveles de plagas y enfermedades. La demanda de alimentos orgánicos se ha incrementado desde hace dos décadas, por lo que producir en baja escala y en forma aislada no puede satisfacer los requerimientos del mercado. Esta demanda se ha convertido en una oportunidad de desarrollo importante en varios países. En superficies mayores tienden a aumentar las poblaciones de plagas y enfermedades, por lo que es necesario implementar actividades que ayuden al sistema a reducir dichas poblaciones. Este tipo de agricultura permite el control biológico, cultural, mecánico y físico, aunque su utilización la limitan los estándares y reglamentos señalados por las agencias certificadoras. Los productores deben determinar el manejo óptimo de plagas mediante estrategias que estén consideradas dentro del ambiente regulatorio del movimiento orgánico. Se presentan algunas alternativas adecuadas para implementar un programa de manejo, con un enfoque que considera la regulación actual para lograr y no poner en riesgo de pérdida, la certificación como productor orgánico

Search for resonant pair production of Higgs bosons decaying to bottom quark-antiquark pairs in proton-proton collisions at 13 TeV

A search for a narrow-width resonance decaying into two Higgs bosons, each decaying into a bottom quark-antiquark pair, is presented. The search is performed using proton-proton collision data corresponding to an integrated luminosity of 35.9 fb$^{-1}$ at $\sqrt{s}=$ 13 TeV recorded by the CMS detector at the LHC. No evidence for such a signal is observed. Upper limits are set on the product of the production cross section for the resonance and the branching fraction for the selected decay mode in the resonance mass range from 260 to 1200 GeV

Search for supersymmetric partners of electrons and muons in proton–proton collisions at s=13TeV

A search for direct production of the supersymmetric (SUSY) partners of electrons or muons is presented in final states with two opposite-charge, same-flavour leptons (electrons and muons), no jets, and large missing transverse momentum. The data sample corresponds to an integrated luminosity of 35.9 fb−1 of proton–proton collisions at s=13TeV, collected with the CMS detector at the LHC in 2016. The search uses the MT2 variable, which generalises the transverse mass for systems with two invisible objects and provides a discrimination against standard model backgrounds containing W bosons. The observed yields are consistent with the expectations from the standard model. The search is interpreted in the context of simplified SUSY models and probes slepton masses up to approximately 290, 400, and 450 GeV, assuming right-handed only, left-handed only, and both right- and left-handed sleptons (mass degenerate selectrons and smuons), and a massless lightest supersymmetric particle. Limits are also set on selectrons and smuons separately. These limits show an improvement on the existing limits of approximately 150 GeV.0info:eu-repo/semantics/publishe