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Effect of Eugenia winzerlingii extracts on Bemisia tabaci and evaluation of its nursery propagation

ANGEL EMMANUEL CRUZ ESTRADA ESAU RUIZ SANCHEZ Irma Leticia Medina Baizabal Eduardo Balam Uc MARIA MARCELA GAMBOA ANGULO (2019)

The development of plant-derived products to control Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) is an urgent need for production of horticultural crops. Plant extracts and essential oils of several species of the genus Eugenia (Myrtaceae) have shown insecticidal activity. In southern Mexico, leaf extracts from Eugenia winzerlingii showed nematicidal effect but its insecticidal properties have not been explored. Therefore, the objective of this study was to evaluate the insecticidal effect of aqueous and organic extracts from E. winzerlingii leaves on B. tabaci egg, nymph and adult stages, and else to explore its nursery propagation. Then, extracts of this species were obtained by maceration with different polarity solvents. Bioassays were carried out on Capsicum chinense leaves. Mortality assays showed that aqueous and total crude ethanol (TCE) extracts necrosed the eggs (LC50 = 0.21% w/v and 4.68 mg/mL, respectively), whereas hexane, ethyl acetate (ETA), residual ethanol and TCE extracts affected the nymphs (LC50 = 0.25 - 4.85 mg/mL). In adults, oviposition inhibition by free choice assay indicated that TCE and ETA extracts had major activity (EC50 = 14.62 and 27.86 µg/cm2 , respectively). On other hand, the sexual and vegetative propagation of E. winzerlingii showed that this species can be easily cultivated by seeds. In conclusion, extracts of E. winzerlingii leaves are highly effective in controlling B. tabaci. TCE extract, in particular, was toxic to three stages of B. tabaci. This plant could be a potential alternative to develop a novel botanical insecticide to manage this destructive pest.

Article

BIOASSAYS EUGENIA WINZERLINGII OVIPOSITION INHIBITION PLANT PROPAGATION BEMISIA TABACI BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA MOLECULAR BIOLOGÍA MOLECULAR DE PLANTAS BIOLOGÍA MOLECULAR DE PLANTAS

Successful community-based seed production strategies

Peter Setimela Emmanuel Monyo Marianne Bänziger (2004)

Designed to address the issues that limit the access of small-scale farmers in sub-Saharan Africa to quality, affordable seed of the crops on which they depend for food security and livelihoods, this collection of articles describes successful principles for and experiences in community-based seed production. Among other things, the anuscripts analyze current seed production systems and models; propose ways to design successful community-based seed production schemes; describe proper seed production practices for selected cereals, vegetatively propagated plants, and other crops; and outline basic business practices for seed producers.

Book

Quality Business management Food security Partnerships Plant propagation Crops Models Seed production Small farms Farmers CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Etiología, histopatología y control de la muerte descendente de injertos de zapote mamey (Pouteria sapota (Jacq.) H. E. Moore

&

Stearn) en Guerrero, México

JUAN MANUEL TOVAR PEDRAZA (2010)

Tesis (Maestría en Ciencias, especialista en Fitopatología).- Colegio de Postgraduados, 2010.

La muerte descendente de varetas injertadas de zapote mamey es el principal problema durante la propagación vegetativa de este frutal en viveros comerciales en Guerrero, México. Lasiodiplodia theobromae, identificado cultural, morfológica y molecularmente, se asoció con este problema en 97 % de los aislamientos obtenidos de varetas necrosadas. Se realizaron pruebas de patogenicidad en varetas injertadas de la selección “El Mexicano”. Las varetas mostraron muerte descendente, caracterizada por secamiento gradual con agrietamiento de la corteza del ápice a la base y crecimiento micelial externo y en la unión del injerto. Picnidios abundantes se observaron en peridermis y cicatrices foliares. El estudio de patogenicidad confirmó a L. theobromae como el agente causal de la muerte descendente de varetas injertadas de zapote mamey en viveros de Guerrero, México. Secciones anatómicas transversales de varetas infectadas artificialmente mostraron picnidios en peridermis. Las células parenquimatosas de la corteza y floema colapsaron y necrosaron. El hongo creció intracelularmente en vasos del xilema y en tejido parenquimatoso medular. El control de este patógeno se realizó mediante pruebas en vivero semi-comercial durante dos épocas de injertación para evaluar la efectividad de tratamientos profilácticos físicos (lavado) y químicos (inmersión en fungicida) en varetas de la selección “El Mexicano”. El lavado de varetas disminuyó la incidencia de la enfermedad hasta 25 %, mientras que el tiabendazol fue el tratamiento químico más efectivo al reducirla en 52 %. La combinación de ambos tratamientos abatió la incidencia hasta 82 %, por lo que se recomienda para el manejo profiláctico de este patógeno en viveros de zapote mamey. Adicionalmente, se realizaron pruebas in vitro de doce fungicidas para la inhibición del crecimiento micelial de L. theobromae. Ciprodinil + fludioxinil, pyraclostrobin + boscalid, prochloraz y tebuconazol fueron los más efectivos con valores de EC50 < 0.1 μg mL-1, seguidos de iprodiona y tiabendazol con valores EC50 < 1.0 μg mL-1. _______________ ETIOLOGY, HISTOPATHOLOGY AND CONTROL OF DIEBACK OF MAMEY SAPOTE (Pouteria sapota (Jacq.) H.E. Moore & Stearn) GRAFTS IN GUERRERO, MEXICO. ABSTRACT : Dieback of mamey sapote grafts is the most important disease during vegetative propagation in commercial nurseries in Guerrero, Mexico. Lasiodiplodia theobromae, identified by cultural, morphological and molecular characterization, was associated with this problem in 97 % of evaluated necrotic rootstocks and scions. Pathogenicity tests were realized with grafted scions of “El Mexicano” selection. Scions developed dieback symptoms and gradual drying with cracking of the bark from the apex to the base. Abundant mycelia and pycnidia were found on inoculated scions. Pathogenicity test confirmed that L. theobromae is the causal agent of the dieback of mamey sapote grafts in nurseries of Guerrero, Mexico. Transverse sections of inoculated scions tissues showed pycnidia in periderm. Parenchymal cells of cortex and phloem collapsed and died. Semi-commercial tests were conducted in mamey sapote nursery during two grafting seasons to evaluate the effectiveness of physical prophylaxis (washing) and chemical treatments (fungicide dip) on scions collected from "El Mexicano" selection. The physical prophylaxis reduced the incidence of the disease up to 25 %, whereas thiabendazole was the most effective chemical treatment to reduce it by 52 %. Combination of physical and chemical prophylactic treatments resulted on an incidence decrease of 82 %, so the combination of both treatments is recommended for the management of L. theobromae in mamey sapote nurseries. Additionally, twelve selected fungicides were tested for in vitro control of this fungus by inhibiting mycelial growth. Cyprodinil + fludioxinil, pyraclostrobin + boscalid, prochloraz and tebuconazole were the most effective fungicides with EC50 values < 0.1 µg mL-1, followed by iprodione and thiabendazole with EC50 values < 1.0 µg mL-1.

Master thesis

Propagación Vivero Fungicidas Lasiodiplodia theobromae Pouteria sapota Propagation Nursery Fungicides Maestría Fitopatología CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Propagation of the information in a one-way quantum computer

Manuel Ávila Aoki (2007)

Both linear momentum and Poynting vector associated with the propagation of information in a one-way quantum computer are studied. It is found that, within the so-called Mean Field Theory (MFT) approximation the total energy, the linear momentum and the Poynting vector associated with the propagation of information are invariant under arbitrary rotations of logical qubits. This means that propagation of the quantum information stored in the entangled state does not depend on the choice of the quantum gates. Due that the involved cluster of neighboring particles is large enough, last property satisfies the scalability test. As a consequence, quantum information in the one-way computer is read, written and processed independently of this choice, which suggests a simple hardware for it. When an external magnetic field is switched on, the invariance under arbitrary rotations of the logic qubits of these quantities is lost, that is, the field induces a preferential direction of propagation of the information which at the same time is optimized while more intense be the field.

Article

Física, Astronomía y Matemáticas Information propagation Poynting vector invariance CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

Cambio climático global y comunidades de microorganismos rizosféricos de fresa silvestre (Fragaria mexicana Schltdl).

ADRIANA PATRICIA GAMBOA MENDOZA (2017)

Tesis (Maestría en Ciencias, especialista en Edafología).- Colegio de Postgraduados, 2017.

El cambio climático global es un fenómeno que ha cobrado gran importancia en los últimos años, debido al impacto que causa en los ecosistemas naturales, la agricultura y las condiciones de vida del ser humano. Para los próximos 100 años, se pronostica un incremento en la temperatura de casi 4°C, lo cual pondrá en riesgo especies que no logren adaptarse. En este estudio se sometieron plantas de fresa silvestre (Fragaria mexicana) a un incremento de temperatura con el fin de evaluar su impacto en la fisiología de la planta y en las comunidades microbianas de la rizósfera. La investigación se realizó en dos etapas. En la primera etapa se generó un protocolo de propagación in vitro de fresa silvestre, para obtener plantas homogéneas y con baja variabilidad genética, de gran utilidad para futuros experimentos. La fresa silvestre mostró ser un excelente candidato para estudios de propagación in vitro ya que presentó un rápido desarrollo y crecimiento de nuevos individuos. Asimismo, se logró establecer el mejor medio y tipo de explante vinculado a un protocolo de propagación in vitro el cual puede ser replicado en otros estudios. En la segunda etapa se evaluaron los efectos de un incremento de temperatura en 5.1°C en plantas de fresa silvestre y en las comunidades rizosféricas asociadas a ésta. Al incrementar la temperatura, las plantas de fresa silvestre presentaron mayor crecimiento en la parte aérea y menor desarrollo en la raíz. Las comunidades de microrganismos rizosféricos, las bacterias fijadoras de nitrógeno de vida libre (BFN) y los hongos micorrízicos arbusculares (HMA), se vieron afectadas negativamente con el incremento de temperatura. La diversidad de las comunidades disminuyó, mientras que la dominancia aumentó al incrementar la temperatura, lo que sugiere que el cambio climático puede favorecer grupos metabólicos como el de los ácidos carboxílicos. _______________ GLOBAL CLIMATE CHANGE AND MICROBIAL COMMUNITIES IN THE RHIZOSPHERE OF WILD STRAWBERRY (Fragaria mexicana Schltdl.). ABSTRACT: Global climate change is a phenomenon that has become more important in recent years. It has a negative impact on natural ecosystems, agriculture and human wellness. One of the most important effects is the projected increase in temperature by almost 4°C during the next 100 years, thereby the escalation of extreme weather events. In this study two experiments were performed. First, an in vitro propagation protocol of wild strawberry was generated to obtain homogenous plants with low genetic variability, useful for future experiments. The wild strawberry has proved to be an excellent candidate for in vitro propagation studies becauses presented a rapid development and growth of new individuals. Also, it was found the best medium and type of explant linked to an in vitro propagation protocol which can be replicated in other studies. In the second experiment the effects of increasing temperature in 5.1°C on wild strawberry plants and them associated rhizospheric communities were evaluated. Wild strawberry plants presented a different response in the aerial part and root with increasing temperature, which is related to the changes observed in the soil, such as an increase in respiration and the rate of mineralization of soil organic matter. Rhizospheric microorganisms communities, free-living nitrogen fixing bacteria (NFB) and arbuscular mycorrhizal fungi (AMF) were negatively affected by warming. The microbial diversity decreased, while dominance increased with increasing temperature, suggesting that climate change may be beneficial for metabolics groups as carboxylics acids.

Master thesis

Propagación Temperatura Diversidad Bacterias fijadoras de nitrógeno Hongos micorrízicos arbusculares Respiración del suelo Biomasa microbiana Propagation Temperature Diversity Nitrogen fixing bacteria Arbuscular mycorrhizal fungi Microbial biomass Edafología Maestría CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO CLIMATOLOGÍA CLIMATOLOGÍA REGIONAL

Propagation Techniques and Agronomic Requirements for the Cultivation of Barbados Aloe (Aloe vera (L.) Burm. F. ) — A Review

Giuseppe Cristiano BERNARDO MURILLO AMADOR Barbara De Lucia (2016)

"Barbados aloe (Aloe vera (L.) Burm. F.) has traditionally been used for healing in natural medicine. However, aloe is now attracting great interest in the global market due to its bioactive chemicals which are extracted from the leaves and used in industrial preparations for pharmaceutical, cosmetic, and food products. Aloe originated from tropical and sub-tropical Africa, but it is also now cultivated in warm climatic areas of Asia, Europe, and America. In this review, the most important factors affecting aloe production are described. We focus on propagation techniques, sustainable agronomic practices and efficient post harvesting and processing systems."

Article

abiotic stress tolerance, burn plant, in vitro propagation protocols, crop husbandry, leaf processing, leaf yield CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS AGRONOMÍA PROPAGACIÓN DE VEGETALES

Reproducción de Oncidium poikilostalix (Kraenzl.) M. W. Chase and N. H. Williams (Orchidaceae), en cafetales en El Soconusco, Chiapas, México

Alfredo García González (2010)

Resumen en español: "Se estudió la reproducción y estructura poblacional de Oncidium poikilostalix (Kraenzl.) M.W. Chase & N.H. Williams (Orchidaceae), durante los años 2008 y 2009. Esta orquídea es nuevo reporte para México en 2008, encontrándose en el Soconusco, Chiapas, creciendo asociada a cafetales de sombra en áreas de los Ejidos Fracción Montecristo (FM) y Benito Juárez El Plan (BJ), municipio de Cacahoatán. Se trazaron tres parcelas de 625 m² (25 x 25 m) en cada uno de los dos cafetales donde se encontró O. poikilostalix. Empleando estas parcelas, fueron caracterizados los cafetales, en cuanto a densidad de cafetos y árboles de sombra, especies de árboles, altura y DBH, además del número y composición de los forofitos ocupados. Los forofitos cafetos y árboles de sombra, fueron zonificados y las orquídeas se dividieron en plántulas (P), juveniles (J) y adultas (A). Se contabilizaron las flores y frutos producidos en ambos años y utilizando tres cápsulas, se obtuvo un promedio de producción de semillas para determinar la lluvia de semillas promedio en los dos años. Tomando muestras de raíces de plántulas y juveniles de O. poikilostalix se determinaron los hongos asociados con esta orquídea, en estas áreas, por micrositio. En FM se contabilizaron 1123 ejemplares (82.63%) de O. poikilostalix y en BJ, 236 (17.37%). De ellos, adheridos a cafetos se hallaron 1060 ejemplares (94.4%) en FM y 214 (91.06%) en BJ, el resto crecía encima de árboles de sombra. A pesar de tener caracteristicas propias de una orquidea de ramilla, el micrositio con mayor presencia de O. poikilostalix en los forofitos cafeto fue las ramas con 703 individuos (55.18%) y en los forofitos árboles, el tronco con 78 individuos (91.76%). En ambos sitios, en el caso de los cafetos, hubo un incremento en el porcentaje reproductor de las poblaciones de 2008 a 2009. El número de flores también aumentó en ambos sitios y forofitos. En FM hubo en 2008, 7047 flores en cafetos y 580 en árboles, para 2009 fueron 10078 y 1563 respectivamente. En BJ hubo 970 y 283 en 2008 y 1431 en cafetos para 2009. En 2008, el porcentaje de polinización para ambas poblaciones en conjunto fue del 1.85%, y en 2009 aumentó a 3.37%. En 2008, fueron producidas 3 387 472 semillas de O. poikilostalix en las 0.375 ha que abarcan las seis parcelas, en 2009, fueron 10 001 096. Lograron identificarse, hasta nivel genero, 13 taxones de hongos asociados a O. poikilostalix. Los géneros presentes fueron: Alternaria, Aspergillus, Epicocum, Fusarium, Rhizoctonia, Rhizopus y Trichoderma. Probablemente Rhizoctonia sp. sea micorrícico en O. poikilostalix. Esta orquídea, a pesar de ser una especie de reciente entrada a México y de tener solo dos poblaciones reportadas hasta el momento, es una especie ampliamente adaptable, pudiéndosele considerar una orquídea maleza. "

Master thesis

Orquídeas;Oncidium poikilostalix;Malezas;Fertilización de las plantas;Dispersión de semillas;Propagación vegetativa;Población vegetal;Café;Inga vera subsp. vera;Hongos micorrízicos;Taxonomía;Morfología vegetal Orchids;Oncidium poikilostalix;Weeds;Fertilization of plants;Seed screenings;Vegetative propagation;Plant populations;Coffee;Inga vera subsp. vera;Mycorrhizal fungal;Taxonomy;Plant morphology BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA CIENCIAS DE LA VIDA

Unraveling the photoactive annihilation mechanism of nanostructures as effective green tools for inhibiting the proliferation of the phytopathogenic bacterium Pseudomonas syringae

J Sergio Casas Flores RUTH BELINDA DOMINGUEZ ESPINDOLA ROBERTO CAMPOSECO SOLIS OLGA ARACELI PATRON SOBERANO VICENTE RODRIGUEZ GONZALEZ (2019)

"The infectious proliferation of phytopathogenic microorganisms depends on a complex sequence of biological events involving host defense, environmental conditions, and chemical and physical interactions between the surface of a plant and microorganisms, which in numerous cases display resistance to conventional microbicides. Among these microorganisms, Pseudomonas syringae (P. syringae) is a Gram-negative bacterium that attacks wounded parts of plants before invading healthy tissues. In order to control P. syringae, considering it to be a phytopathogenic model, an effective method featuring silver nanoparticles (AgNPs) functionalized on titanate nanotubes (Nts) used as photoactive antibacterial agents was investigated to understand the effective photoactive annihilation mechanism. The high dispersion of AgNPs over the Nts boosted charge carrier separation by generating reactive oxygen species (ROS) under visible-light, which stressed the bacteria and enhanced the biocidal effect by quickly preventing the rod-shaped P. syringae bacteria from proliferating. Biological transmission and scanning electron microscopy revealed damaged P. syringae cells that underwent the formation of outer membrane vesicles, caused by photo-assisted annihilation, which is considered to be an indication of a critical defense mechanism. The unusual synergistic properties of the Nts, and their low cost and practical synthesis, made these nanocomposites promising green tools that can positively and swiftly photokill P. syringae within 30 min."

Article

Escherichia-coli Photocatalytic degradation Titanate nanotubes Pathogen Plant Inactivation Diseases BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA

Heterologous expression of a novel psychrophilic Cu/Zn superoxide dismutase from Deschampsia antarctica

SERGIO ANGEL GARCIA ECHAURI LEANDRO GABRIEL ORDONEZ ACEVEDO JUAN ANTONIO ROJAS CONTRERAS ANA PAULINA BARBA DE LA ROSA ANTONIO DE LEON RODRIGUEZ (2009)

"Superoxide dismutase (SOD) catalyzes the conversion of the superoxide radical (O2−) into oxygen and hydrogen peroxide. Deschampsia antarctica is a plant that grows in Antarctica and survives to extreme low temperature and high UV radiation, thus it is an ideal model to study novel antioxidants. A cDNA Cu/Zn-SOD gene from D. antarctica was cloned into a pET vector and expressed in Escherichia coli BL21-SI. 112 mg/L of recombinant Cu/Zn-SOD was attained in batch cultures in bioreactor. Using Ni-affinity gel chromatography, the recombinant Cu/Zn-SOD was recovered with a purity of 90% and a specific enzyme activity of 749 at 25 °C. However, zymogram test showed that the enzyme has more activity at 4 °C. This D. antarctica SOD could be used to reduce the oxidation of refrigerated and frozen foods."

Article

Antioxidant Plant Extremophil Psychrophilic enzyme Photo-oxidation Oxidative stress CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Genetic loci conditioning adult plant resistance to the Ug99 Race group and seedling resistance to races TRTTF and TTTTF of the stem rust pathogen in wheat landrace CItr 15026

Ebrahiem Babiker John Bonman Matthew Rouse Maria Newcomb sridhar bhavani (2017)

Wheat landrace citr 15026 previously showed adult plant resistance (apr) to the ug99 stem rust race group in kenya and seedling resistance to puccinia graminis f. sp. tritici races qfcsc, ttttf, and trttf. Citr 15026 was crossed to susceptible accessions lmpg-6 and red bobs, and 180 double haploid (dh) lines and 140 recombinant inbred lines (ril), respectively, were developed. The 90k wheat iselect single-nucleotide polymorphism platform was used to genotype the parents and populations. Parents and 180 dh lines were evaluated in the field in kenya for three seasons. A major quantitative trait locus (qtl) for apr was consistently detected on chromosome arm 6as. This qtl was further detected in the ril population screened in kenya for one season. Parents, f1, and the two populations were tested as seedlings against races trttf and ttttf. In addition, the dh population was tested against race qfcsc. Goodness-of-fit tests indicated that the trttf resistance in citr 15026 was controlled by two complementary genes whereas the ttttf and qfcsc resistance was conditioned by one dominant gene. The trttf resistance loci mapped to chromosome arms 6as and 6ds, whereas the ttttf and qfcsc resistance locus mapped to the same region on 6ds as the trttf resistance. The apr identified in citr 15026 should be useful in developing cultivars with durable stem rust resistance.

Article

PUCCINIA GRAMINIS WHEAT QUANTITATIVE TRAIT LOCI Mapping Plant Resistance CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA