Revista de la Facultad de Agronomía de la Universidad del Zulia <p>The Journal of the Faculty of Agronomy, Universidad del Zulia is a publication of the Agronomic Research Institute of the Faculty of Agronomy, Universidad del Zulia, published since 1968 and is supported by the Universidad del Zulia, in order to disseminate the results of researchers Venezuelans and other parts of the world, related to the agricultural field. The Rev. Fac. Agron. (LUZ) publishes four issues per year, i. e., every three months, under continuous publication format (rolling pass). , with original and unpublished scientific articles, technical notes, review articles, quick communications, extensive summaries of congresses and scientific meetings related to the agricultural area for the consideration of the Editorial Committee. The journal publishes research products of high scientific quality and promotes the exchange of publications and scientific activity at the agricultural level, in the areas of Plant Production, Animal Production, Food Technology and Socioeconomics. The topics included in these areas are: agrosystem management, environment, agricultural biotechnology, meat science, milk science, rural development, agricultural economics, agricultural entomology, fertilizers, post-harvest physiology, plant physiology, physiology and animal reproduction, pastures and forages, animal and plant genetics and improvement, weeds, animal nutrition, plant pathology, agri-food safety, agri-food systems and soils.</p> Universidad del Zulia en-US Revista de la Facultad de Agronomía de la Universidad del Zulia 0378-7818 Glyoxalase I (GLX-I) analysis in native maize from Oaxaca, Mexico, infected with Aspergillus flavus in vitro <p>The glyoxalase system plays an important role in various physiological processes in plants when they are subjected to different types of stress, whether physical, chemical or biological. <em>Aspergillus flavus</em> is an aflatoxin-producing fungus that contaminates dry grains, leading to a gradual deterioration of the grains and a significant reduction in their nutritional value. The objective of the present study was to evaluate the activity of the enzyme glyoxalase I (GLX-I) in maize coleoptiles from Oaxaca in response to infection caused by <em>Aspergillus flavus</em>. Nine maize samples from four different races were analyzed. The samples were inoculated with a suspension of <em>Aspergillus flavus</em> spores of known concentration and total protein extraction and quantification were performed on the coleoptiles, and GLX-I activity was determined by quantifying the amount of S-lactoylglutathione produced per minute. In addition, analysis of gene expression by reverse transcriptase polymerase chain reaction (RT-PCR) was performed. The inoculated maize coleoptiles showed symptoms of infection, color changes and wilting. The concentration of total proteins decreased significantly in the extracts of four samples in the presence of the fungus. In the GLX-I analysis, two samples had the highest enzymatic activity in the infected coleoptile extract with respect to the healthy one, in addition to presenting greater expression of the gene in the RT-PCR assay, this due to the response to <em>Aspergillus flavus</em> infection.</p> Carlos Francisco Varapizuela-Sánchez Marco Antonio Sánchez-Medina María del Socorro Pina-Canseco Nora Hilda Rosas-Murrieta Alma Dolores Pérez-Santiago Iván Antonio García-Montalvo Copyright (c) 2022 Carlos Francisco Varapizuela-Sánchez, Marco Antonio Sánchez-Medina, María del Socorro Pina-Canseco, Nora Hilda Rosas-Murrieta, Alma Dolores Pérez-Santiago, Iván Antonio García-Montalvo 2022-09-21 2022-09-21 39 4 e223946 e223946 Anatomical changes caused by Ralstonia solanacearum Smith and Pectobacterium carotovorum (Jones) in Solanum tuberosum L. stems <p>Potato (<em>Solanum tuberosum</em> L.) is a crop notably affected by various pathogens, including bacterial, and it is important to study the histological changes that they produce to understand the symptoms associated with each disease. The objective of this research was to determine the anatomical changes that occur in potato stems due to the infection caused by <em>Ralstonia solanacearum</em> and <em>Pectobacterium carotovorum</em>. An assay was carried out with 45-day-old plants of the Kennebec variety, which were infiltrated in the basal part of the main stem with a suspension of 108 CFU.mL<sup>-1</sup> of <em>R. solanacearum</em> and <em>P. carotovorum,</em> including a control treatment in which the plants were treated with sterile distilled water. Twelve days after inoculation, segments were taken from the second internode of the main stem and they were fixed in FAA (formaldehyde-acetic acid-ethanol 70 %) until processing to obtain cross sections of the stem. In the plants inoculated with <em>R. solancaearum</em>, invasion of the xylem vessels by the bacterium and formation of tyloses in some of them was observed. In the case of <em>P. carotovorum</em>, necrosis in the form of discontinuous bands in the epidermal cells, cortex, vascular cylinder, and pith was observed, as well as obstruction in xylem vessels by the bacteria and tylosis in some of them. The anatomical changes in the stem, induced by the two bacteria studied, are directly linked to the symptomatology of the disease that each of them causes in the potato crop.</p> Yonis Hernández Marina García Rafael Mejías Copyright (c) 2022 Yonis Hernández, Marina García, Rafael Mejías 2022-10-05 2022-10-05 39 4 e223947 e223947