{"title":"Anatomical changes caused by Ralstonia solanacearum Smith and Pectobacterium carotovorum (Jones) in Solanum tuberosum L. stems","authors":"Y. Hernández, Marina García, Rafael Mejías","doi":"10.47280/revfacagron(luz).v39.n4.02","DOIUrl":"https://doi.org/10.47280/revfacagron(luz).v39.n4.02","url":null,"abstract":"Potato (Solanum tuberosum 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 Ralstonia solanacearum and Pectobacterium carotovorum. 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-1 of R. solanacearum and P. carotovorum, 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 R. solancaearum, invasion of the xylem vessels by the bacterium and formation of tyloses in some of them was observed. In the case of P. carotovorum, 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.","PeriodicalId":54470,"journal":{"name":"Revista De La Facultad De Agronomia De La Universidad Del Zulia","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2022-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84808342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gonzalo Bolívar, Ernesto Cañarte, Luis Duicela, J. Navarrete
{"title":"Interaction between the incidence of Prodiplosis longifila Gagné (Diptera: Cecidomyiidae) and management practices in tomato crops in Manabí, Ecuador","authors":"Gonzalo Bolívar, Ernesto Cañarte, Luis Duicela, J. Navarrete","doi":"10.47280/revfacagron(luz).v39.n4.05","DOIUrl":"https://doi.org/10.47280/revfacagron(luz).v39.n4.05","url":null,"abstract":"The insect pest Prodiplosis longifila Gagné (Diptera: Cecidomyiidae), causes severe losses to the tomato crop in Ecuador, in the provinces of Manabí, Pichincha, Carchi, Cotopaxi, Azuay, and Chimborazo, where the main producing areas of this solanaceous crop in the country are located. The objective of this research was to study the interaction of the incidence of this pest with tomato crop management practices. The evaluations were carried out in twenty-five production units in different cantons of Manabí: in Bolívar (two), Portoviejo (eight), Rocafuerte (five), Santa Ana (one), Sucre (three) and Tosagua (six). Each unit had an area of 2500 m2, where 25 plants were randomly marked and the number of healthy, infested and damaged shoots was recorded, as well as the number of healthy and damaged fruits. In addition, a survey was applied to growers to determine the management practices carried out during the crop cycle. Descriptive analysis, significance tests, hierarchical clustering and chi-square tests were carried out. It was determined that in the cantons of Portoviejo, Tosagua and Rocafuerte, infestations did not exceed 13 % and a severity of up to 15 %, reaching 25 % of damaged fruit in Tosagua. The agronomic practices applied were trellising, drip and gravity irrigation, collection of infested fruit and chemical insecticides. There was an interaction with P. longifila between infested fruit collection and trellising, which influenced its infestation and severity, respectively. These incidences were significantly high at harvest, where highly toxic insecticide applications were substantially increased indiscriminately.","PeriodicalId":54470,"journal":{"name":"Revista De La Facultad De Agronomia De La Universidad Del Zulia","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80210245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carlos Varapizuela-Sánchez, M. Sánchez-Medina, María Pina-Canseco, N. Rosas-Murrieta, A. Pérez-Santiago, I. García-Montalvo
{"title":"Glyoxalase I (GLX-I) analysis in native maize from Oaxaca, Mexico, infected with Aspergillus\u0000flavus in vitro","authors":"Carlos Varapizuela-Sánchez, M. Sánchez-Medina, María Pina-Canseco, N. Rosas-Murrieta, A. Pérez-Santiago, I. García-Montalvo","doi":"10.47280/revfacagron(luz).v39.n4.01","DOIUrl":"https://doi.org/10.47280/revfacagron(luz).v39.n4.01","url":null,"abstract":"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. Aspergillus flavus 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 Aspergillus flavus. Nine maize samples from four different races were analyzed. The samples were inoculated with a suspension of Aspergillus flavus 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 Aspergillus flavus infection.","PeriodicalId":54470,"journal":{"name":"Revista De La Facultad De Agronomia De La Universidad Del Zulia","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80895418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}