Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Más filtros










Intervalo de año de publicación
1.
Plant Dis ; 2022 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-36194732

RESUMEN

Chard (Beta vulgaris var. cicla; Chenopodiaceae) is a vegetable native to the Mediterranean, widely cultivated for its nutritional properties. In June 2020, an outbreak of powdery mildew was detected in a commercial crop of chard in San Martín Texmelucan, Puebla (19°14'37.1"N; 98°27'12.5"W), Mexico. The disease was present in 86% of the plants (n=400) and the pathogen was found to cover up to 95% of the surface of the leaves. Initially, small whitish patches were observed on both sides of the leaves. Subsequently, the patches grew rapidly to cover most of the leaf surface and premature senescence of infected leaves was observed. The signs of the pathogen were observed as abundant whitish masses of conidia. Microscopic analysis of the fungus showed amphigenous mycelia with lobed hyphal appressoria. Conidiophores (n=30) were simple and erect, 93133 × 7.58.5 µm. Foot cells (n=30) were cylindrical, predominately straight, and rarely somewhat curved at the base, 30.036.5 µm, followed by a longer cell and two shorter cells, and the conidium. Conidia (n=100) were hyaline, ellipsoid-ovoid, 3745 × 1416 µm. Germ tubes (n =30) were terminal, short (0.52.0 times the conidial width) and stout. Conidial appressoria (n=30) were mostly lobed, showing from 2-6 lobes. Chasmothecia were not found. The morphological characteristics observed correspond to previous descriptions of Erysiphe betae by Braun and Cook et al. (2012). A voucher specimen (accession no. UACH450) was deposited in the Department of Agricultural Parasitology Herbarium at the Chapingo Autonomous University. To confirm identification, DNA was extracted from the fungus, and the internal transcribed spacer (ITS) and the 28S gene region of rDNA from one sample were amplified by PCR, using the primers ITS1/ITS4 (White et al. 1990) and PM3 (Takamatsu and Kano 2001)/TW14 (Mori et al. 2000). The sequences obtained from our specimen were registered to the GenBank under the accession numbers ON157053 and ON157047 for ITS and LSU, respectively. Our sequences shared 100% identity for ITS (KX574674) and 99.8% for LSU (OM033348 and OM368494) with sequences of E. betae in BLAST'n search. Based on phylogenetic analysis using the Maximum Likelihood method including a published ITS + 28S dataset for Erysiphe species, the isolate UACH450 was grouped into a clade with E. betae. Takamatsu et al. (2015) found that E. betae, E. malvae and E. heraclei are phylogenetically indistinguishable (they form the E. heraclei species complex), nevertheless, E. malavae infects Lavatera and Malva (Malvaceae), E. heraclei predominately forms on hosts of Apiaceae and E. betae is commonly found on Beta and Chenopodium (Chenopodiaceae) (Braun and Cook 2012). Pathogenicity was verified by spraying a suspension of conidia (1107 conidia/ml) onto the leaves of six healthy chard plants and six plants were sprayed with sterile distilled water to serve as controls. All plants were maintained at temperatures from 28 2 °C and relative humidity of 802 %. All inoculated leaves developed powdery mildew symptoms after 14 days, whereas the control plants remained symptomless. The pathogenicity test was performed twice, observing the same results. The recovered pathogen showed the same morphological characteristics as the inoculated pathogen, thus fulfilling Koch's postulates. To our knowledge, this is the first report of Erysiphe betae causing powdery mildew on Beta vulgaris var. cicla in Mexico. This pathogen has been previously reported in Iraq (Amano, 1986) and Greece (Vakalounakis and Kavroulakis, 2017) on Beta vulgaris var. cicla. Also, Erysiphe betae has been reported in Mexico on Chenopodium and throughout the world on sugar beet (Farr and Rossman, 2022). This pathogen is a major issue as it can completely cover the leaves of the diseased plants, making them difficult to market.

2.
Perspect. nutr. hum ; 20(1): 15-22, ene.-jun. 2018. tab
Artículo en Español | LILACS | ID: biblio-976330

RESUMEN

Resumen Antecedentes: el piñón de pino es un fruto seco de excelentes propiedades nutricionales. Objetivo: evaluar el efecto del consumo de piñón en la ganancia de peso corporal y de órganos de ratas con dieta alta en grasas. Materiales y métodos: se alimentó a 24 ratas macho Sprague Dawley con dieta control, dieta alta en grasa, o dieta alta en grasa con 2 % de piñones, (n=8 por grupo). Luego de 28 días, los animales se pesaron, se sacrificaron y se obtuvo grasa mesentérica, retroperitoneal, inguinal y epididimal. Se extrajeron y se pesaron el hígado, los riñones y el corazón. Resultados: la ingestión alta en grasa y alta en grasa con 2 % de piñones fue semejante, menor que la de dieta control (p<0,05). Las ratas con dieta alta en grasa con 2 % de piñones mostraron mayor incremento ponderal y peso corporal final (p<0,05), y la eficiencia de las dietas alta en grasa y alta en grasa con 2 % de piñones fue mayor que la de dieta control (p<0,05). El peso relativo de hígado, corazón, riñones y panículos adiposos fue semejante en los tres grupos. Conclusiones: el consumo de dietas altas en grasa ocasiona un mayor aumento de peso en comparación con una normograsa. La dieta alta en grasa con 2 % de piñones no afecta la ganancia ponderal, el peso relativo de órganos ni los depósitos de grasa observados con dieta alta en grasa.


Abstract Background: Pine nus have an outstanding nutritional value. Objective: To evaluate the effect of the intake of pine nuts on body and organ weight gain in rats fed a high fat diet. Materials and Methods: 24 male Sprague Dawley rats were fed control diet, high fat diet, or high fat with 2 % pine nuts, (n=8 per group). After 28 days the animals were weighed and killed, and mesenteric, retroperitoneal, inguinal, and epididimal fat pads were weighed as well as liver, kidneys, and heart. Results: The intake of high fat and high fat with 2 % pine nuts diets was similar and lower than fed control diet (p<0.05). Rats fed high fat with 2 % pine nuts exhibited higher weight gain and final body weight (p<0.05). The dietary efficiency of high fat and high fat with 2 % pine nuts diets were higher than fed control (p<0.05). The relative weights of liver, heart, kidneys and fat pads were similar in all groups. Conclusion: High fat intake generates higher body fat gain compared with an isocaloric control diet. High fat with 2% pine nuts diet did not affect body weight gain, relative organ weight, or fat pads weight compared with high fat diet.

3.
Rev. chil. obstet. ginecol ; 52(6): 337-44, 1987. ilus, tab
Artículo en Español | LILACS | ID: lil-58719

RESUMEN

El espermatozoide humano sufre una serie de cambios antes de ser capaz de fecundar un ovocito. Estos cambios pueden dividirse en capacitación, hiperactivación, reacción del acrosoma y fusión de las membranas gaméticas. El análisis del semen de rutina da poca información acerca de la capacidad del espermatozoide de experimentar estos cambios. El bioensayo de penetración del ovocito de criceto es una prueba optativa que puede ser usada con el objeto de analizar la capacidad fértil del espermatozoide humano. Se ha demostrado que existe correlación entre este bioensayo de fusión de membranas gaméticas heterólogas y la fecundación in vivo e in vitro. La presente revisión analiza los materiales y métodos utilizados para llevar a cabo esta prueba, y brinda información respecto a su aplicación en el tratamiento de la pareje infértil


Asunto(s)
Cricetinae , Técnicas In Vitro , Interacciones Espermatozoide-Óvulo , Espermatozoides/fisiología , Bioensayo , Oocitos/fisiología , Semen/análisis , Capacitación Espermática , Motilidad Espermática
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...