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1.
Braz J Biol ; 83: e270870, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37585927

RESUMEN

The leaf crown borer Eupalamides cyparissias (Cramer, 1775) is an important pest of coconut (Cocos nucifera L.) and other palms (Arecaceae) of economic importance, attacking the base of leaves, inflorescences, and infructescences, increasing fruit abortion. The objective of this study was to evaluate the spatial correlation of the infestation rate of E. cyparissias in coconut plantation blocks in the Brazilian Amazon, from January to December 2019, in the city of Santa Izabel, Pará, Brazil. The study area is a farm subdivided into 157 blocks of a commercial plantation of the green dwarf coconut. The Local Moran's Index was used to evaluate the existence of spatial autocorrelation of the E. cyparissias infestation rate in the 157 blocks with neighboring blocks. The infestation rate was calculated by the ratio between the number of plants attacked by the borer and the total number of plants in a block. There is a significant correlation of the symptomatology of the attack by E. cyparissias in the blocks of the experimental area, which indicates an aggregated pattern of distribution. There is no significant correlation between the attack by the borer and the age of the coconut tree; however there is a significant correlation between the attack by the borer and proximity to forest areas. These results indicate that forest regions are foci of infestation by the borer in coconut plantations.


Asunto(s)
Arecaceae , Lepidópteros , Animales , Cocos , Hojas de la Planta , Brasil
2.
Bull Entomol Res ; : 1-14, 2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-34130764

RESUMEN

Plants not only respond to herbivorous damage but adjust their defense system after egg deposition by pest insects. Thereby, parasitoids use oviposition-induced plant volatiles to locate their hosts. We investigated the olfactory behavioral responses of Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) to volatile blends emitted by maize (Zea mays L.) with singular and stacked events after oviposition by Spodoptera frugiperda Smith, 1797 (Hymenoptera: Trichogrammatidae) moths. Additionally, we examined possible variations in gene expression and on oviposition-induced volatiles. We used a Y-tube olfactometer to test for the wasp responses to volatiles released by maize plants oviposited by S. frugiperda and not-oviposited plants. Using the real-time PCR technique (qRT-PCR), we analyzed the expression of lipoxygenase and three terpene synthases genes, which are enzymes involved in the synthesis of volatile compounds that attract parasitoids of S. frugiperda. Olfactometer tests showed that T. pretiosum is strongly attracted by volatiles from transgenic maize emitted by S. frugiperda oviposition (VTPRO 3, more than 75% individuals were attracted). The relative expression of genes TPS10, LOX e STC was higher in transgenic hybrids than in the conventional (isogenic line) hybrids. The GC-MS analysis revealed that some volatile compounds are released exclusively by transgenic maize. This study provides evidence that transgenic hybrids enhanced chemical cues under oviposition-induction and helped to increase T. pretiosum efficiency in S. frugiperda control. This finding shows that among the evaluated hybrids, genetically modified hybrids can improve the biological control programs, since they potentialize the egg parasitoid foraging, integrating pest management.

3.
Br J Nutr ; 126(11): 1611-1625, 2021 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-33583435

RESUMEN

The intestinal tract is the entry gate for nutrients and symbiotic organisms, being in constant contact with external environment. DNA methylation is one of the keys to how environmental conditions, diet and nutritional status included, shape functionality in the gut and systemically. This review aims to summarise findings on the importance of methylation to gut development, differentiation and function. Evidence to date on how external factors such as diet, dietary supplements, nutritional status and microbiota modifications modulate intestinal function through DNA methylation is also presented.


Asunto(s)
Metilación de ADN , Microbioma Gastrointestinal , Dieta , Expresión Génica , Intestinos , Nutrientes
5.
HIV Med ; 22(3): 212-217, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33012065

RESUMEN

OBJECTIVES: We aimed to characterize neurocognitive impairment (NI) in an HIV-2 population using an observational cross-sectional study in four Portuguese hospitals. METHODS: Adult HIV-2-infected patients were included. Montreal Cognitive Assessment Test (MoCA) and International HIV Dementia Scale (IHDS) scales were applied for screening of NI. Patient Health Questionnaire-9 (PHQ-9) and Instrumental Activities of Daily Living (IADL) scales were used for assessment of depression and functionality. A multivariate analysis was performed to assess for risk factors for NI. RESULTS: Eighty-one patients were included, 50.6% of African origin (n = 41) and 49.4% of Portuguese origin (n = 40). The MoCA scale showed alterations in 81.5% of patients (100% of migrants vs. 62.5% of non-migrants, P < 0.001) and the IHDS scale showed alterations in 42%. Both scales were altered simultaneously in 35.8%. Variables independently associated with NI were age [odds ratio (OR) = 0.885] and migrant status (OR = 9.150). CONCLUSIONS: Neurocognitive impairment (both scales altered) was present in 35.8%, which is comparable to what is described for HIV-1. The MoCA performed worse in the migrant population and might not be applicable in this setting.


Asunto(s)
Complejo SIDA Demencia , Disfunción Cognitiva , Infecciones por VIH , Actividades Cotidianas , Adulto , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/etiología , Estudios Transversales , Infecciones por VIH/complicaciones , Infecciones por VIH/psicología , VIH-2 , Humanos , Pruebas de Estado Mental y Demencia , Pruebas Neuropsicológicas
7.
Curr Neurol Neurosci Rep ; 20(11): 49, 2020 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-32880775

RESUMEN

PURPOSE OF REVIEW: In 2016, the World Health Organization declared the Zika virus (ZIKV) outbreak a Public Health Emergency of International Concern following a cluster of associated neurological disorders and neonatal malformations. Our aim is to review the clinical and neuroimaging findings seen in congenital Zika syndrome. RECENT FINDINGS: ZIKV injures neural progenitor cells in the hippocampus, a brain region important for learning, memory, cognition, and emotion/stress response. Positron emission tomography has revealed global neuroinflammation in ZIKV infection in animal models. Congenital Zika syndrome is associated with a spectrum of brain abnormalities, including microcephaly, parenchymal calcifications, malformations of cortical development and defective neuronal migration, corpus callosum abnormalities, ventriculomegaly, and brainstem and cerebellar abnormalities.


Asunto(s)
Microcefalia , Complicaciones Infecciosas del Embarazo , Infección por el Virus Zika , Virus Zika , Encéfalo/diagnóstico por imagen , Femenino , Humanos , Microcefalia/diagnóstico por imagen , Microcefalia/epidemiología , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Infección por el Virus Zika/complicaciones , Infección por el Virus Zika/diagnóstico por imagen , Infección por el Virus Zika/epidemiología
8.
Trop Anim Health Prod ; 52(5): 2461-2468, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32350820

RESUMEN

The use of agricultural by-products might provide an important alternative to improve animal agriculture and to reduce feeding costs. The effects of inclusion in the diet of four levels of delinted cottonseed (0, 80, 160, and 240 g/kg) on intake, digestibility, nitrogen balance, blood parameters, and the ingestive behaviour of confined sheep were studied. Twenty-four mixed-breed rams with an average body weight of 27.6 ± 2.9 kg were used in a completely randomised design with four treatments. The addition of delinted cottonseed (DCS) did not alter (P > 0.05) the intake of dry matter, crude protein, organic matter, neutral detergent fibre, or ether extract in the two forms calculated (g/day and % body weight). The use of different levels of DCS in sheep feed did not influence (P > 0.05) the voluntary water intake. The dietary DCS levels linearly affected (P < 0.05) the digestibility coefficients of the dry matter (DM), organic matter, neutral detergent fibre, ether extract, and non-fibrous carbohydrates. The DCS inclusion levels did not affect the nitrogen balance (P = 0.22), plasma concentrations of urea (P = 0.51), and glucose (P = 0.17).The feeding efficiency and rumination in g DM/h reduced linearly (P < 0.05) with the addition of DCS in the diet. Therefore, the addition of delinted cottonseed affects the intake, digestibility, and ingestive behaviour of confined sheep, and the addition of up to 80 g/kg delinted cottonseed in the diet of confined sheep is recommended.


Asunto(s)
Alimentación Animal/análisis , Dieta/veterinaria , Gossypium/química , Semillas/química , Ovinos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Peso Corporal , Fibras de la Dieta/metabolismo , Digestión , Conducta Alimentaria , Masculino , Enfermedades de las Ovejas
9.
Br J Radiol ; 93(1110): 20190692, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32293191

RESUMEN

OBJECTIVE: The internal target volume (ITV) strategy generates larger planning target volumes (PTVs) in locally advanced non-small cell lung cancer (LA-NSCLC) than the Mid-position (Mid-p) strategy. We investigated the benefit of the Mid-p strategy regarding PTV reduction and dose to the organs at risk (OARs). METHODS: 44 patients with LA-NSCLC were included in a randomized clinical study to compare ITV and Mid-p strategies. GTV were delineated by a physician on maximum intensity projection images and on Mid-p images from four-dimensional CTs. CTVs were obtained by adding 6 mm uniform margin for microscopic extension. CTV to PTV margins were calculated using the van Herk's recipe for setup and delineation errors. For the Mid-p strategy, the mean target motion amplitude was added as a random error. For both strategies, three-dimensional conformal plans delivering 60-66 Gy to PTV were performed. PTVs, dose-volume parameters for OARs (lung, esophagus, heart, spinal cord) were reported and compared. RESULTS: With the Mid-p strategy, the median of volume reduction was 23.5 cm3 (p = 0.012) and 8.8 cm3 (p = 0.0083) for PTVT and PTVN respectively; the median mean lung dose reduction was 0.51 Gy (p = 0.0057). For 37.1% of the patients, delineation errors led to smaller PTV with the ITV strategy than with the Mid-p strategy. CONCLUSION: PTV and mean lung dose were significantly reduced using the Mid-p strategy. Delineation uncertainty can unfavorably impact the advantage. ADVANCES IN KNOWLEDGE: To the best of our knowledge, this is the first dosimetric comparison study between ITV and Mid-p strategies for LA-NSCLC.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Neoplasias Pulmonares/radioterapia , Movimientos de los Órganos , Respiración , Anciano , Plexo Braquial/diagnóstico por imagen , Plexo Braquial/efectos de la radiación , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/patología , Esófago/diagnóstico por imagen , Esófago/efectos de la radiación , Tomografía Computarizada Cuatridimensional , Corazón/diagnóstico por imagen , Corazón/efectos de la radiación , Humanos , Pulmón/diagnóstico por imagen , Pulmón/efectos de la radiación , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Órganos en Riesgo/diagnóstico por imagen , Órganos en Riesgo/efectos de la radiación , Estudios Prospectivos , Traumatismos por Radiación/prevención & control , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Radioterapia Conformacional/métodos , Médula Espinal/diagnóstico por imagen , Médula Espinal/efectos de la radiación , Carga Tumoral
10.
J Appl Microbiol ; 129(4): 1071-1078, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32248631

RESUMEN

AIM: To investigate factors influencing Campylobacter spp. colonization of broiler chickens. METHODS AND RESULTS: Campylobacters were isolated from caeca from 319 flocks of two different breeds (199 Cobb and 120 Hubbard), reared as standard (199), Freedom Food/corn fed (57), free-range (47) or organic (16). The standard category exclusively used Cobb birds slaughtered at 38-41 days. The Freedom Food/corn-fed and free-range Hubbard birds were slaughtered at 49-56 days and the organic flocks at 70 days. Campylobacters were picked at random from direct plates. Both breed of chicken (Hubbard) and age at slaughter were independently associated with increased likelihood of colonization by Campylobacter coli rather than Campylobacter jejuni, but breed could not be separated from other aspects of husbandry with the data available. CONCLUSIONS: Chickens are frequently colonized by C. jejuni and C. coli and most human infections originate from poultry. In most developed countries approximately 90% of human infections are caused by C. jejuni, but fewer than 10% by C. coli. This might be due to C. coli being less pathogenic than C. jejuni to humans, and/or to chicken meat carrying fewer C. coli than C. jejuni. More investigations are needed into these aspects before it can be concluded that slaughtering older birds from slower-growing breeds would reduce the risk of human Campylobacter disease. SIGNIFICANCE AND IMPACT OF THE STUDY: Meat from certain breeds of poultry are predominantly colonized by C. coli rather than C. jejuni. More research is needed to understand the impact this may have on the number and severity of human campylobacter infections.


Asunto(s)
Infecciones por Campylobacter/veterinaria , Campylobacter/aislamiento & purificación , Aves de Corral/microbiología , Crianza de Animales Domésticos/métodos , Animales , Cruzamiento , Campylobacter/clasificación , Infecciones por Campylobacter/microbiología , Ciego/microbiología , Pollos , Humanos , Factores de Tiempo
11.
Scand J Gastroenterol ; 55(3): 371-375, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32150486

RESUMEN

Background: A new computer algorithm called Express-View has recently been introduced by Mirocam, but data concerning its application and efficacy are scarce.Objective: To evaluate the lesion detection rate, per-patient sensitivity and the diagnostic accuracy using Express-View.Methods: All patients who performed CE between January 2018 and June 2019, whose indication was obscure gastrointestinal bleeding (OGIB) and with findings on CE, were included. Lesions identified in conventional reading were selected and considered as reference.Results: Eighty-nine patients were included, 50.6% male, with a mean age of 68.4 years-old (±12.3). The Express-View mode detected 85.5% of lesions previously detected by conventional reading (524 out of 613). There were 89 missed lesions, mainly erosions or ulcers (44.9%) and angioectasias (38.2%). The lesion detection rate was found to be lower in the jejunum and ileum compared to extra-small bowel locations and duodenum (p = .04). Although Express-View had a per-patient sensitivity for all lesions of 56.2% and a per-patient sensitivity for all clinically significant lesions of 83.1%, it achieved a diagnostic accuracy of 91%.Conclusions: The per-patient sensitivity for all lesions was shown to be below expectations, although the lesion detection rate, the per-patient sensitivity for all clinically significant lesions, and the diagnostic accuracy were shown to be higher.


Asunto(s)
Endoscopía Capsular/métodos , Hemorragia Gastrointestinal/diagnóstico por imagen , Intestino Delgado/patología , Programas Informáticos , Anciano , Anciano de 80 o más Años , Femenino , Hemorragia Gastrointestinal/etiología , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos
12.
Neotrop Entomol ; 49(2): 302-310, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31970681

RESUMEN

Little is known about the effects of genetically modified corn plants on the foraging of Spodoptera frugiperda (J.E. Smith). Therefore, this study examines whether singular herbicide-tolerant and insect-resistant plants and their stacked events interfere with food preference and oviposition of S. frugiperda. Two non-Bt corn hybrids and three Bt-hybrids, some of them with glyphosate tolerance (GT), were evaluated. Food preference of larvae and biological parameters were assessed. Oviposition preference bioassays involved choice and no choice condition in plants uninfested and previously infested by larvae in a greenhouse and in the field. The results indicate that there is no relationship between preference of larvae and adult moths. Adult females selected preferentially transgenic hybrids, while larvae selected non-Bt hybrid. Fall armyworm larvae avoid Bt-toxin-expressing leaf tissues, survived only on the non-Bt leaf tissues, and showed minor differences in other life-history traits reared on GT and non-transgenic corn leaf tissues. Female moths showed preference for transgenic plants to lay eggs, but with variable output between previously infested and uninfested plants with larvae. The fact that moths preferred Ag 3700RR2 and non-Bt hybrids for oviposition supports the refuge's strategy aiming at producing susceptible individuals. The use of this hybrid must be integrated with a program of control. The results showed also the importance of correct hybrid selection as part of insect resistance management to Bt-plants. The implications of these findings for understanding the impacts of plant-mediated cues on pest behavior in transgenic crop systems are discussed.


Asunto(s)
Conducta de Elección , Conducta Alimentaria , Oviposición , Spodoptera/fisiología , Zea mays/genética , Animales , Toxinas de Bacillus thuringiensis/genética , Conducta Animal , Femenino , Plantas Modificadas Genéticamente/genética
14.
Nutr Hosp ; 35(1): 104-109, 2018 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-29565157

RESUMEN

OBJECTIVE: The aim of this study was to analyze the influence of liver transplantation in food intake and nutritional status of severe cirrhotic patients. METHODS: The sample consisted of 23 patients who underwent liver transplantation. Three 24-hour dietary recall were applied and anthropometric measurements were collected before and three months after transplantation. The consumption of macronutrients and fat soluble vitamins were also evaluated. The anthropometric data evaluated were body mass index, abdominal circumference, percentage of adequacy of arm circumference, triceps skinfold thickness and arm muscle circumference. Related mean comparison tests, comparison of changes in the proportions of categorical variables and correlation of quantitative variables were used in the statistical analysis. Data were considered to be significant when p < 0.05. RESULTS: Most patients were female and aged between 40 and 65 years. The average consumption of calories, proteins, lipids, cholesterol and monounsaturated fatty acids was significantly higher after liver transplantation (p < 0.05). The average of anthropometric parameters did not differ significantly between the evaluated times. There was no significant change in nutrient intake or anthropometric classification after transplantation. Most patients were classified as malnourished or overweight after transplantation, according to some anthropometric parameters. CONCLUSION: Food consumption changed after transplantation. There was no change in the nutritional status from pre- to post-transplant but, in general, most patients had altered nutritional status in both evaluation moments.


Asunto(s)
Ingestión de Alimentos , Cirrosis Hepática/metabolismo , Cirrosis Hepática/cirugía , Trasplante de Hígado , Evaluación Nutricional , Adulto , Anciano , Femenino , Humanos , Cirrosis Hepática/psicología , Trasplante de Hígado/psicología , Masculino , Persona de Mediana Edad , Estado Nutricional
15.
Nutr. hosp ; 35(1): 104-109, ene.-feb. 2018. tab, graf
Artículo en Inglés | IBECS | ID: ibc-172096

RESUMEN

Objective: The aim of this study was to analyze the influence of liver transplantation in food intake and nutritional status of severe cirrhotic patients. Methods: The sample consisted of 23 patients who underwent liver transplantation. Three 24-hour dietary recall were applied and anthropometric measurements were collected before and three months after transplantation. The consumption of macronutrients and fat soluble vitamins were also evaluated. The anthropometric data evaluated were body mass index, abdominal circumference, percentage of adequacy of arm circumference, triceps skinfold thickness and arm muscle circumference. Related mean comparison tests, comparison of changes in the proportions of categorical variables and correlation of quantitative variables were used in the statistical analysis. Data were considered to be significant when p < 0.05. Results: Most patients were female and aged between 40 and 65 years. The average consumption of calories, proteins, lipids, cholesterol and monounsaturated fatty acids was significantly higher after liver transplantation (p < 0.05). The average of anthropometric parameters did not differ significantly between the evaluated times. There was no significant change in nutrient intake or anthropometric classification after transplantation. Most patients were classified as malnourished or overweight after transplantation, according to some anthropometric parameters. Conclusion: Food consumption changed after transplantation. There was no change in the nutritional status from pre- to post-transplant but, in general, most patients had altered nutritional status in both evaluation moments (AU)


Objetivo: el objetivo de este estudio fue hacer un análisis de las influencias del trasplante de hígado en el consumo alimentario y estado nutricional de pacientes cirróticos graves. Métodos: la muestra fue de 23 pacientes a los que se hizo trasplante de hígado. Se recopilan los datos antropométricos, además de tres recordatorios alimentarios de 24 horas antes y tres meses tras el trasplante. El consumo de macronutrientes y vitaminas liposolubles también fue evaluado. Los datos antropométricos evaluados fueron: índice de masa corporal, circunferencia abdominal, porcentual de adecuación del contorno de cintura, los pliegues cutáneos tricipital y de la circunferencia muscular del brazo. En el análisis estadístico se utilizaron tests de comparación de medias relacionadas, comparación de los cambios en las proporciones de las variables categóricas y la correlación de las variables cuantitativas. Los datos fueron considerados significativos cuando p < 0,05. Resultados: la mayoría de los pacientes estudiados eran del sexo femenino y con edad entre 40 y 65 años. El consumo medio de calorías proteínas, lípidos, colesterol y ácido graso monoinsaturado fue significativamente mayor después del trasplante hepático (p < 0,05). La media de los parámetros antropométricos no difirió significativamente entre los momentos evaluados. No hubo cambio significativo en la ingestión de nutrientes y en la clasificación antropométrica después del trasplante. La mayoría de los pacientes fueron clasificados como desnutridos o con exceso de peso tras el trasplante, de acuerdo con algunos parámetros antropométricos. Conclusión: el consumo alimentario fue modificado después del trasplante. No hubo alteración del estado nutricional del preoperatorio comparado con el postoperatorio, pero de una forma general, la mayoría de los pacientes presentaron alteraciones de su estado nutricional en los dos momentos de la evaluación (AU)


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Cirrosis Hepática/cirugía , Trasplante de Hígado , Evaluación Nutricional , Estado Nutricional , Periodo Posoperatorio , 24457 , Conducta Alimentaria , Pesos y Medidas Corporales/estadística & datos numéricos , Factores de Riesgo
16.
Reprod Domest Anim ; 53(2): 393-400, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29194804

RESUMEN

The objective was to study the use of ultrasound as a complementary test in the breeding soundness evaluation in male pigs and study the pattern of echogenicity of the testicular parenchyma in boars of different racial groups. Twenty-six adult boars from four different racial groups were used, 10 from the Piau breed (group 1), four from the commercial and finishing group (group 2), six Pietrain breed (group 3) and six from the Duroc breed (group 4). All animals were evaluated for breeding soundness evaluation and the ultrasound examination of the testicles. The groups of animals that were evaluated showed no difference in the main semen parameters that were evaluated, except for the sperm volume, concentration of the ejaculated sperm and the supravital staining; the lowest figures were for the animals from the Piau breed (group 1). In relation to the testicular biometrics, Duroc animals (group 4) had a greater scrotal width compared to the other groups. But when we assessed the intensity of pixels of the testicles, there was a difference between groups. The groups 2 (finishing animals), 3 (Pietrain) and 4 had no difference between themselves. Group 3 had greater pixel intensity in relation to group 1. Of the 26 animals studied, five showed an abnormality during ultrasound evaluation, like hydrocele, hyperechoic mass in the testicular parenchyma, cyst in the head of the epididymis and the presence of fluid in the head and tail of the epididymis. The various animal groups studied did not differ in the principal reproductive parameters evaluated, showing that despite the great variability of reproductive traits between breeds and within the same breed, the breeding soundness evaluation, the more complete it is, is essential for the selection of breeders and the ultrasonography of the reproductive system becomes an important addition in this examination.


Asunto(s)
Análisis de Semen/veterinaria , Sus scrofa/fisiología , Testículo/diagnóstico por imagen , Ultrasonografía/veterinaria , Animales , Cruzamiento , Procesamiento de Imagen Asistido por Computador , Masculino , Semen/fisiología , Motilidad Espermática , Espermatozoides , Testículo/patología , Ultrasonografía/métodos
17.
Genet Mol Res ; 16(3)2017 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-28692118

RESUMEN

In recent years, there has been a large incidence of fungi causing "ear rot" in maize in Brazil, the main fungus being Fusarium verticillioides. The most efficient and competitive alternative for control of this disease consists of using maize hybrids resistant to this pathogen. Thus, the aims of this study were to analyze the genetic variability of maize inbred lines in regard to resistance to ear rot to observe if there is a maternal effect to resistance to ear rot, to study genetic control of the traits evaluated in hybrids originating from inbred lines of the maize breeding program at the Agriculture Department of Universidade Federal de Lavras (Lavras, MG, Brazil), and characterize the gene expression pattern related to the plant defense mechanism against F. verticillioides. High genetic availability was observed for resistance to this disease among the inbred lines evaluated. Considering combined diallel analysis, it was observed that the mean square of general combining ability (GCA) was not significant for the characteristic under study. However, specific combining ability (SCA) was significant, which indicates the predominance of non-additive effects involved in control of the characteristic for the population evaluated. A maternal effect was not observed for the characteristic of ear rot resistance in this study. Inbred lines 22, 58, and 91 showed potential for use in breeding programs aiming at resistance to F. verticillioides. Only two genes, LOX8 and Hsp82, had a satisfactory result that was able to be related to a plant defense mechanism when there is ear rot infection, though expression of these genes was observed in only one susceptible genotype. Thus, the genes LOX8 and Hsp82 are potential molecular markers for selection of maize inbred lines resistant to F. verticillioides.


Asunto(s)
Fitomejoramiento , Inmunidad de la Planta/genética , Selección Genética , Zea mays/genética , Fusarium/patogenicidad , Regulación de la Expresión Génica de las Plantas , Marcadores Genéticos , Variación Genética , Proteínas de Choque Térmico/genética , Endogamia , Lipooxigenasa/genética , Herencia Materna , Proteínas de Plantas/genética , Zea mays/inmunología , Zea mays/microbiología
18.
Genet Mol Res ; 16(2)2017 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-28671255

RESUMEN

In several crops, the water deficit is perhaps the main limiting factor in the search for high yields. The objective of this study was to evaluate the phenotypic stability of maize hybrids in environments with and without water restriction using the analytical factor (AF) approach. We evaluated 171 maize hybrids in 14 environments, divided into environments with (A1, A2, A3, A4, A5, A6, and A7) and without (A8, A9, A10, A11, A12, A13, and A14) water restriction, over a period of 7 years. Each year, 36 hybrids were evaluated. A square lattice design (6 x 6) was used, with common treatments between years. The characteristics of grain yield (GY), male flowering (MF) and female flowering (FF), plant height (PH), and ear height (EH) were evaluated. Phenotypic adaptability and stability of the hybrids were also verified. Hybrids G66, G99, G86, and G26 were the most stable and showed potential for use in environments with and without water restriction. The AF models showed to be useful for evaluating hybrids over many years, allowing selection of better hybrids with adaptability, specific and general stability, and correlation of hybrids with their production components, in addition to allowing identification of mega-environments that permit stability in the response of the adapted hybrids.


Asunto(s)
Inestabilidad Genómica , Hibridación Genética , Fitomejoramiento/métodos , Estrés Fisiológico , Zea mays/genética , Sequías , Ambiente , Modelos Genéticos , Carácter Cuantitativo Heredable , Zea mays/crecimiento & desarrollo
19.
Reprod Domest Anim ; 52(2): 335-343, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28111814

RESUMEN

This study was conducted to characterize the daily profile of testosterone secretion and its mean concentrations in the four seasons as well as to evaluate the semen characteristics and testicular biometry of Mangalarga Marchador stallions throughout the year in a tropical region. Three stallions were submitted to semen collections and evaluation of testicular biometry every 14 days along a year. Blood samples were collected once at the middle of each season, in a 20-min interval during 24 hr in order to evaluate the testosterone secretion profiles among seasons. Testosterone concentrations along the day were higher at the beginning of the afternoon (from 12:00 to 15:00 hr), but a circadian secretion was not clearly observed. Mean testosterone concentrations did not differ among seasons (p > .05), but a pattern of secretion along the day showed variations with higher concentrations in the afternoon during the winter. Ejaculate volume was higher during summer; however, sperm motility decreased in summer and spring. Total sperm in ejaculate, sperm morphology and testicular biometry kept constant along the year showing no differences among the seasons. The results demonstrated that in a tropical region, reproductive aspects of stallions did not show a clearly defined seasonal variation, and months of autumn and winter were not unsuitable for reproduction of the males.


Asunto(s)
Caballos/fisiología , Análisis de Semen/veterinaria , Semen/fisiología , Testículo/anatomía & histología , Testosterona/sangre , Animales , Brasil , Masculino , Oportunidad Relativa , Periodicidad , Estaciones del Año , Temperatura
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