Search

Toxoplasma gondii es un parásito intracelular obligado de alta prevalencia a nivel mundial, presenta una gran diversidad genética, característica que le permite poder infectar a una gran variedad de hospederos como aves, reptiles y mamíferos, incluidos los humanos. La principal forma de transmisión es a través de la ingesta de quistes tisulares y ooquistes contenidos en los alimentos poco cocidos. Diversos estudios han indicado que a parte de lo genotipos conocidos de T. gondii, existen cepas más agresivas del parásito conocidas como exóticas o atípicas, las cuales están relacionadas con infecciones más graves en los animales silvestres, lo que provoca la disminución de especies de importancia económica y cultural en muchos países. En esta revisión corta se utilizaron buscadores académicos de acceso abierto mediante el uso de palabras clave y páginas web relacionadas con estudios sobre la diversidad genética de T. gondii en animales silvestres.

The primary objective of this research study is to assess the performance of 25 genotypes of "criolla" or "chaucha" potato (Solanum tuberosum group phureja) under natural infestation conditions of the phytopathogen Rhizoctonia solani. A randomized complete block design with three replications is conducted in the Mapachico district, Pasto-Nariño (Colombia). The results show that during the first evaluation stage, the Criolla-Colombia genotype present the lowest phythopathogen incidence (5.74%). During tuberization, the Mambera and Ratona-Rosada genotypes show an 18.92% incidence each, and at harvest, the Ratona-Rosada shows a 10.27% incidence. The genotypes Ratona-Amarilla, Ratona-Rosada, and Criolla-Galeras achieve the highest commercial yield with 20.49, 21.25, and 23.39 t. ha-1 respectively. It is concluded that the S. tuberosum genotypes Criolla-NN, Mambera, Ratona-Amarilla, Ratona-Rosada, Criolla-Galeras, Criolla-Colombia, Tornilla-Negra, Punte, and Ratona are the best prospects for genetic improvement programs because of their low susceptibility to the phytopathogen R. solani. [ABSTRACT FROM AUTHOR]

Cocoa cultivation plays an important role in Colombian rural development. In addition to being identified as a potential substitute for illicit crops, cocoa provides a livelihood for some 65,000 families in Colombia. However, the low productivity of the crop indicates that its potential is still limited. The objective of this research was to evaluate the cocoa cultivar CNCh12, previously selected by Compañía Nacional de Chocolates’ breeding program, and to compare its traits with a commercial cultivar, the CCN51 clon. For both cacao cultivars the next variables were measured: productivity (Kg/Ha/year), sexual compatibility, resistance to M. roreri, beans characteristics (physical, chemical and functional), morphological traits, and the flavor of cocoa liquor. The results indicate that the cultivar CNCh12 is highly productive, self-compatible, and with moderate resistance to Frosty Pod. This genotype also has fine and flavor attributes and functional traits that satisfy the chocolate industry needs. In this way, Compañía Nacional de Chocolates consolidates its position as the first private company to develop plant materials endorsed by the National Registry of Commercial Crops of the Instituto Colombiano Agropecuario-ICA, thus strengthening the genetic diversity that the country possesses. [ABSTRACT FROM AUTHOR]

Hevea brasiliensis is the greatest source of natural rubber and raw material in several industrial products manufacture. In Colombia, it has been commercially established in five productive units; however, the genetic basis is limited and foliar diseases have influenced the development and the production. In La Libertad Research Center (Villavicencio) and Taluma Experimental Field (Puerto López) of the Corporación Colombiana de Investigación Agropecuaria – AGROSAVIA, clonal trials, at small-scale and large-scale, were established to evaluate the performance assessment, associated with growth, of seven clones from CIRAD-Michelin selection Collection series CDC, FDR, MDF y PMB, and FX 3864 and RRIM 600 as well. In juvenile stage, the trunk circumference (CIRC) was measured every six months, and the annual increase average (IMA-CIRC) was calculated. Variance analysis and means comparison were carried out. At eight years of age, the FDR 5788 clone showed IMA-CIRC of 8.20 cm year-1 and 6.87 cm year-1 in La Libertad and Taluma, respectively; differences in growth between clones were observed. In the Piedemonte llanero (La Libertad), the FDR 5788 and RRIM 600 clones were notable for their growth, whereas in the Altilllanura (Puerto López) PMB 1 and FDR 5788 were remarkable. In La Libertad, the FDR 5788, RRIM 600 and CDC 312 clones exceeded the CIRC of 50 cm at sixth year, in contrast to Taluma, where it occurred at seventh year for PMB1 and DFR 5788. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Gastroenterología del Perú is the property of Sociedad de Gastroenterologia del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background. In Mexico, there are variants of chili peppers (Capsicum spp.) in terms of shape, flavor, size and pungency, where the greatest diversity of native chili peppers is found in rural communities of the Mexican tropics. Objective. To characterize the phenotypic parameters of eight genotypes of native chili peppers from Olinalá, located in the mountain region of the state of Guerrero. Methodology. Eight materials collected from chili peppers were planted under greenhouse conditions, in a completely randomized design, with six replicates, three plants per experimental unit and a distance between plants and rows of 40 cm. The plants were established in a greenhouse, in a black polyethylene bag, with mountain soil as a substrate. Results. The genotypes Cascabel (CAS), Gallo gallina mediano (GGM), Gallo gallina grande (GGG) and Larguillo grande (LG) presented erect growth, Chilaca (CHI) of intermediate type, and Larguillo chico (LCH), Serrano (S) and Mochiteco (M) were compact. All genotypes have a green cylindrical stem and dense branching, lanceolate leaves (except M, which had oval leaves), with one flower per axil in an erect position and white, except CAS, which has light yellow flowers. The shape of the fruit varied between triangular (GGM, GGG and M), elongated (LGH, LG and S), round (CAS) and bell-shaped (CHI), and red when ripe. The genotypes that registered the largest plant and leaf size were LG, S, GGG and LCH. On the other hand, the largest fruit size was recorded in CHI with a fruit length of 8.53 cm; fruit width of 5.96 cm, and LG with fruit length of 8.67 cm; fruit width of 5.92 cm; while the fresh weight was higher in CHI (33.55 g), GGG (23.50 g) and GGM (22.60 g). Implications. The study provides information on the behavior of qualitative and quantitative morphological aspects of chili peppers grown in Teticic, Olinalá, in the state of Guerrero. In the same way, it allows to assess the possibility of selecting outstanding materials. Conclusions. The chili genotypes showed variability in different qualitative and quantitative characteristics of the plant, leaf, flower and fruit, so they are an alternative to select outstanding materials to design a program for the improvement and conservation of these genetic resources.

La fermentación del cacao es un proceso clave y relevante en la síntesis de moléculas precursoras de aroma y sabor. El objetivo de este estudio fue la caracterización microbiológica, sensorial y bromatológica de la fermentación de los granos de cacao en los genotipos CCN 51 e ICS 95. Se realizó la extracción del grano llevándose a fermentadores semi-escalera durante siete días, tomándose muestras cada 24h para identificación. En laboratorio, se efectuó el aislamiento de los microorganismos e identificación, para levaduras, con la amplificación de la región ITS (Internal Transcribed Spacer) y las bacterias mediante la secuenciación del gen 16S ARN ribosomal. Para el análisis sensorial y bromatológico, se llevó, ha secado el grano hasta obtener 7% de humedad, identificando el perfil sensorial a partir de licor de cacao, a través de evaluadores entrenados. Se identificaron microorganismos como: Candida orthopsilosis, Hanseniaspora opuntiae, Issatchenkia orientalis, Saccharomyces cerevisiae, Kodamaea ohmeri, Tatumella sp., Tatunella ptyseos, Lysinibacillus, Lactiplantibacillus plantarum, Acetobacter pasteurianus, Acetobacter sp., Gluconobacter sp., Gluconacetobacter sp., Bacillus sp., Bacillus cereus y Serratia marcescens. Como resultado sensorial se determinó que el ICS 95 presentó mayores descriptores sensoriales positivos como nuez, frutal y floral en comparación al CCN 51, que refleja sabores básicos más intensos. Por el contrario, CCN 51 se resaltó en mayor proporción los polifenoles, la teobromina y carbohidratos. Estos resultados serán el punto de partida sobre la potencialidad que brindan los microorganismos en la calidad sensorial, para así mejorar de manera significativa los procesos de fermentación a nivel industrial.

El guayabo (Psidium guajava) es una especie de importancia económica en diferentes países del mundo, especialmente por la producción de frutos comestibles, su alto contenido de vitamina C y su maleabilidad para la transformación agroindustrial. La Colección Colombiana de Guayaba conservada en Agrosavia resguarda la variabilidad de esta especie y algunas relacionadas, no obstante, se tienen estudios parciales que limitan el potencial de su uso. El objetivo fue evaluar y caracterizar las variables fisicoquímicas del fruto en busca de identificar accesiones con atributos de interés agroindustrial. Para ello se evaluaron 29 descriptores (17 cuantitativos y 12 cualitativos) en frutos de las 41 accesiones que componen la colección. La información obtenida fue sometida a un análisis de componentes principales y a otro de correspondencia múltiple. En los análisis cualitativos se encontró que el germoplasma evaluado se caracteriza por tener frutos de forma convexa con cuello, pulpa de color rosado con textura granulosa, color verde predominante en el epicarpio, inserción de pedúnculo oblicua, semillas de forma oblonga y forma de ápice y fruta con ombligo en el eje polar. En los análisis cuantitativos, 20 accesiones presentaron porcentajes de pulpa entre el 97 % y el 99 %, donde el contenido de sólidos solubles totales de la población evaluada fluctuó entre 4,3 y 10,5 °Brix; la relación de vitamina C osciló entre 28,3 y 208,26 mg/100 g de muestra y el peso del fruto estuvo entre 18,84 y 363,53 g, siendo las accesiones 25, 33 y 36 seleccionadas como promisorias.

Livestock farming is an activity of greater importance from an economic, social, cultural and environmental point of view, it contributes to the gross domestic product and generates employment. Production is affected in the dry season due to food shortages. For this reason, at the Portoviejo Experimental Station of the National Agricultural Research Institute, corn genotypes are evaluated for the production and conservation processes of forage in the form of silage. The test was installed at the Porvenir of Toachi facility, canton Santo Domingo, province of Santo Domingo de los Tsáchilas. A divided plot design was used, with a 3x4 factorial arrangement, each treatment consisted of six ten-meter-long beds. The information was tabulated in the R program under the analysis of variance with separation of means for the multiple test of DGC probability at 5%. The hybrid INIAP 554 at a density of 125,000 plants per hectare obtained the best yield of green forage (29,028.59 kgha-1) and the highest average dry matter (30.5%) of the silage, the hybrid INIAP 551 at a density of 125,000 plants per hectare presented the lowest lodging values (3%). There were no significant differences for germination percentage, days to male flowering, plant height and fermentative characteristics of the silage. It is concluded that the hybrid INIAP 554 at a density of 125,000 plants per hectare, produces a greater amount of green forage, under the climatic conditions of Porvenir of Toachi. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

nuevos cultivares en la Empresa Azucarera “5 de septiembre”, el objetivo general consistió en realizar el estudio de B80250, C86-156 y C97-445, para mejorar la estructura de dichos cultivares. El experimento se estableció en marzo de 2021 en la localidad La Julia (N 22º 25' 2,2064” W -80º 30’ 1,152”), suelo Pardo con carbonatos y las evaluaciones correspondieron a la cosecha de planta con 12 meses, en las que se tuvo en cuenta el rendimiento agrícola, contenido azucarero y otros indicadores de la eficiencia industrial. Quedó corroborado que C97-445 y C86-156 por sus potenciales agroindustriales y seguridad fitosanitaria, pueden ser la solución de la riesgosa explotación actual de C86-12 y C90-469. Se recomienda dar continuidad al trabajo en otras cosechas y a partir de la experiencia implementar estudios similares con otros cultivares y ambientes. El enfoque teórico asumido es de carácter cuantitativo, con el empleo de una metodología experimental y se dan a conocer los resultados de la investigación.

Contexto: En el Cuba aún no se ha informado la respuesta de los principales genotipos de Coffea arabica L. injertados sobre Coffea canephora en presencia de cepa de rizobio promotora del crecimiento vegetal. Objetivo: Evaluar el efecto de Rhizobium alamii Rpr2, en el desarrollo de C. arabica L., injertadas de forma individual sobre el patrón C. canephora (Robusta). Métodos: El ensayo se condujo bajo un diseño de bloques al azar en arreglo factorial 4x2, con cuatro réplicas. Los factores fueron cuatro genotipos de C. arabica L. (Isla 6-14, Isla 5-15, Isla 6-11 y San Ramón) y dos niveles de aplicación de rizobio (con y sin aplicación). Se evaluó los días al prendimiento, porcentaje de prendimiento del injerto, altura del injerto, diámetro del tallo del injerto, número de pares hojas del injerto, área foliar, masa seca foliar, crecimiento de la raíz, volumen de la raíz y masa seca de la raíz. Resultados: Los resultados mostraron la interacción que existe entre el tipo de la especie C. arabica injertada y la cepa R. alamii Rpr2. El injerto Isla 6-14/Robusta inoculado se mostró superior con respecto a los demás tratamientos y controles, lo cual lo convierte en una variante a emplear en la caficultura. Conclusiones: El uso de bacterias promotoras do crecimiento vegetal es una alternativa eficaz en la estimulación y desarrollo de injertos que puede redundar en una mayor disponibilidad de posturas aptas para ampliar el volumen de café a ser establecido en condiciones de campo.

Phosphate fertilization of cassava cultivars leads to increased production costs that may be economically viable depending on the quantity used and the corresponding productivity. In this sense, the objective of the work was to analyse the economic viability of the irrigated cultivation of table cassava cultivars in response to the application of phosphorus doses in the Brazilian semiarid region. Two agricultural crops were conducted at the Experimental Farm Rafael Fernandes, Mossoró, RN, from June 2018 to April 2019 and from June 2019 to April 2020. The experimental design was in randomized blocks arranged in subdivided plots, with four replications. The doses of phosphorus (0, 60, 120, 180, and 240 kg ha-1 of P2O5) were applied to the plots and the table cassava cultivars (Água Morna, BRS Gema de Ovo, Recife and Venâncio) arranged in the subplots. The total costs for one hectare of cultivation were estimated and the gross income, net income, rate of return, and profitability index were calculated. The use of phosphate fertilizer was economically viable for the cassava cultivars studied in the two crops. The cultivars Água Morna, BRS Gema de Ovo, and Recife are the best cultivation options for the semiarid region of Rio Grande do Norteas they give high yields with the highest profitability. The Recife cultivar was the region's most profitable cultivation, with a profit ranging from R$ 40,331.07 ha-1 to R$ 57,603.46 ha-1 in both seasons, with an average recommendation of 120 kg ha-1 of P2O5. [ABSTRACT FROM AUTHOR]

Introduction: food addiction is associated with genetic polymorphisms and decreased antioxidant intake. Objectives: this study determined the associations among food addiction, dopamine receptor 2 (DRD2) and toll-interleukin 1 receptor (TIR) domain-containing adaptor protein (TIRAP rs625413) gene polymorphisms, antioxidant capacities, and zinc levels among recreationally active Turkish women. Methods: the Yale Food Addiction Scale was used to evaluate the food addiction status. Serum antioxidant capacities and zinc levels were evaluated by blood analyses. Deoxyribonucleic acid (DNA) extraction was performed using peripheral blood leukocytes, and the polymorphism status of the DRD2 Taq 1A and TIRAP genes was investigated using a commercial kit. Results: the frequencies of the heterozygous genotypes of DRD2 Taq 1A and TIRAP were 23.1 % and 31.4 %, respectively, and the frequency of risk allele homozygous genotypes was 3.2 %. Most participants (94.4 %) had a nonpolymorphic/wild (CC) genotype in both genes; however, 11.5 % of the participants had a food addiction. The differences between serum antioxidant capacities, zinc levels, and body mass indices of those with and without food addiction were statistically significant. However, there were no differences in the serum zinc and antioxidant levels among the different genotypes. Conclusion: food addiction in young Turkish women was not associated with DRD2 Taq 1A or TIRAP polymorphisms but was associated with serum antioxidant capacities and zinc levels. Further studies on different loci of the same genes or genotypes of different genes with larger sample sizes are warranted. [ABSTRACT FROM AUTHOR]

Introduction. Blastocystis sp is a parasitic protozoan found in the intestinal tract of man and some animals, and it is estimated that it infects more than 1,000 million people in the world. In the national parasitism survey, it was reported with a prevalence of 52% in the northern Andean region. The aim of this study was to determine the genotypes of Blastocystis sp associated with different sources of transmission in rural areas of the department of Quindío. Materials and Methods. Forty-two coprological samples were obtained from children between 0 and 14 years of age, 17 from animal feces, 17 from food, 28 from inert surfaces, 15 from soil, 18 from household water and 3 from water sources. DNA extraction and PCR amplification were performed for Blastocystis sp using the SSADNr gene as target. The sequences were aligned with ClustalW and phylogenetic trees were performed with the program (MEGA11). Results. Of the 140 samples collected between coprological samples of children and environmental matrices, we found a prevalence of Blastocystis sp of 23.5% in food, 22.2% in the home network and 4.75% in the child population, there was no statistical evidence implying an association between the presence of this protozoan and sociodemographic variables. Subtype 2 was found associated with infant population and subtype 3 associated with environmental matrices (water and food) and infant population. Conclusions: We report the presence of Blastocystis sp in tomato and carrot, in the home network and infant population in a rural area of the department of Quindío where the associated subtypes were subtype 2 and 3. [ABSTRACT FROM AUTHOR]

The fermentation of cocoa is a process carried out by microorganisms whose composition and activity is relevant in the synthesis of precursor molecules for flavor and aroma. The objective of this study was to carry out a microbiological, sensory, and bromatological characterization of cocoa beans during the fermentation process in genotypes ICS 95 and CCN 51. For this, cocoa beans were extracted during the fermentation process, taking samples every 24 hours for seven days. In the laboratory, the isolation and identification of the present microorganisms were carried out. Yeasts were identified using amplification of the ITS region (Internal Transcribed Spacer), while bacteria were identified by sequencing the 16S ribosomal RNA gene. Subsequently, cocoa beans were dried to 7% moisture, identifying the sensory profile from prepared cocoa liquor, through trained evaluators. The analyses allowed the identification of microorganisms such as Candida orthopsilosis, Hanseniaspora opuntiae, Issatchenkia orientalis, Saccharomyces cerevisiae, Kodamaea ohmeri, Tatumella sp., Tatunella ptyseos, Lysinibacillus, Lactiplantibacillus plantarum, Acetobacter pasteurianus, Acetobacter sp., Gluconobacter sp., Gluconacetobacter sp., Bacillus sp., Bacillus cereus and Serratia marcescens. Sensory analyses indicated that the ICS 95 genotype presented better descriptors than CCN 51, such as walnut, fruit and floral, reflecting more intense basic flavors. On the contrary, in the CCN 51 genotype, a higher proportion of polyphenols, theobromine, and carbohydrates were detected. These results will allow determining the potential effects of these microorganisms on the sensory quality of cocoa beans, to significantly improve fermentation processes at an industrial level. [ABSTRACT FROM AUTHOR]

This study evaluated the chemical composition of pearl millet seeds belonging to different genotypes by biplot analysis. Seeds of 26 different pearl millet populations obtained from ICRISAT (International Crops Research Institute for the Semi-Arid Tropics) within the scope of TÜBİTAK 219O103 run by Şırnak University were used. The seeds were ground and analyzed for their chemical composition, i.e., acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP), digestible dry matter (DDM) and dry matter intake (DMI) rate. The results revealed that crude protein ratio varied between 11.74-19.24%, whereas ADF ratio differed between 3.44-11.43%. Similarly, NDF ratio varied between 10.23-23.47%, while DDM ratio ranged between 79.98-86.21%. Likewise, DMI ratio differed between 5.11-11.72%. Scatter plot obtained after biplot analysis indicated three different groups based on the analyzed traits. The first group contained DDM and DMI, whereas the second group consisted of ADF and NDF. The protein ratio was in the third group. It was determined that ADF-NDF and DMI-DDM properties were negatively correlated with each other. According to biplot, genotypes 'A5-13', 'A13-6' and 'B1-7' were prominent for ADF -NDF, DMI-DDM, and protein ratio, respectively. Therefore, these genotypes can be used in future studies to induce the desired traits. [ABSTRACT FROM AUTHOR]

Studies that evaluate the quality of the strawberry fruit, depending on the different genetic materials and places of cultivation, are still scarce in Brazil. The objective of this work was to evaluate the quality of fruits of advanced genotypes of strawberry with Italian genetics, in the municipality of Farroupilha, belonging to the Serrana region of Rio Grande do Sul. The experimental design was in randomized blocks, with four replications and 10 plants per plot, in two production cycles, containing 21 treatments in the 2018/2019 cycle and 23 treatments in the 2019/2020 cycle. The variables were quantified: fresh mass of commercial fruits (g fruit-1); luminosity and chroma of the epidermis; hue angle; pulp firmness (g); titratable acidity content (g 100g-1 of citric acid); soluble solids content (°Brix) and soluble solids/titratable acidity ratio (SS/AT). Among the genotypes evaluated, the genotypes FRF PIR 075.08, ITA 10.128.09, and FRF FC 104.01, have superior fruit quality, showing greater potential to become recommended cultivars for cultivation in the Serrana region of Rio Grande do Sul, together with the cultivar Pircinque. [ABSTRACT FROM AUTHOR]

Introduction and aims: Colombia has high incidence levels of gastric cancer that can be explained by the genetic variability of Helicobacter pylori (H. pylori). Our aim was to establish the relation of the H. pylori CagA and VacA genotypes to dysplasia and gastric cancer, in a high-risk population. Material and methods: A case-control study was conducted on 202 patients from a high-risk cancer zone. Patients with dysplasia and gastric cancer (cases) and patients with nonatrophic gastritis (controls) were included. Endoscopic sampling and histologic classification were carried out according to the Sydney system and the Lauren classification. Genetic information was obtained through polymerase chain reaction on paraffin blocks. The measures of association of the variables of interest were evaluated in bivariate and multivariate models. A P

Objetivo: evaluar la tolerancia de 14 híbridos de arroz a P. oryzae bajo las condiciones de producción de la región Pacífico Central de Costa Rica. Materiales y métodos: se obtuvo la semilla realizando un bloque de cruzamientos en el que se utilizaron cinco parentales con tolerancia a P. oryzae. Además de la tolerancia al hongo, cuantificada en escala de severidad, se midieron variables de interés agronómico como altura de planta (cm), panículas por planta, granos por panícula, granos llenos por panícula, granos vanos por panícula y peso de 1 000 granos (g), todas ellas siguiendo el protocolo de medición estándar IRRI para arroz. Resultados: el cruce 3x1 mostró alta tolerancia a P. oryzae (p

En Costa Rica la semilla importada de chile dulce tiene un alto costo para los productores, lo cual hace necesario la obtención de nuevas variedades locales. En cualquier programa de mejora, es necesario conocer la diversidad genética del material que se utiliza. Debido a ello, se planteó evaluar la variabilidad morfoagronómica de individuos F2 provenientes del cruce entre parentales de chile de forma lamuyo y blocky para así seleccionar los mejores genotipos en el desarrollo de nuevas variedades. Producto de la polinización manual entre un parental hembra de forma lamuyo y tres parentales machos de forma blocky se obtuvieron tres líneas F1. Se seleccionaron las mejores plantas por cruce para ser llevadas a F2 por autopolinización y evaluar la progenie. En la F2 se evaluaron variables cuantitativas: peso del fruto (g), grosor del fruto (mm), longitud del fruto (cm), cantidad de frutos y altura de planta (cm). Como primer resultado se obtuvo la segregación de caracteres para color y forma. El cruce RxR fue el que mejor se comportó para la mayoría de variables, excepto para la longitud de fruto y altura de planta. Según el análisis de componentes principales, todos los caracteres mostraron contribución en al menos uno de los cruces. Con los resultados obtenidos se seleccionaron los mejores fenotipos, priorizando los de forma blocky. La evaluación de la variabilidad morfoagronómica en el presente estudio determinó que todos los caracteres analizados tienen variabilidad suficiente para ser seleccionados y obtener fenotipos novedosos y de interés agronómico.

México es considerado centro de origen del chile (Capsicum annuum L.) y tiene dos grupos de chiles: los comunes (disponibles en todo el país) y los locales. La presente investigación se realizó con el propósito de conocer el comportamiento de los genotipos de chile Huacle negro, rojo y amarillo (chiles locales de Cuicatlán, Oaxaca, utiliza dos para elaborar el mole negro), así como evaluar su rendimiento y calidad bajo condiciones de invernadero con dos sistemas de producción: orgánico e inorgánico, con aplicación y no aplicación de rizo-bacterias Azospirillum sp. La siembra se realizó en charolas de 200 cavidades, utilizando peat moss como sustrato. Los sustratos utilizados fueron: arena + compost con la dosis de a) 20% y b) 35% y para el testigo c) arena al 100%. Las macetas se colocaron a doble hilera en tresbolillo espaciadas a 30 cm entre planta y planta y 80 cm entre pasillos. El diseño experimental utilizado fue en bloques completamente al azar con dos repeticiones y una unidad experimental de ocho macetas por genotipo. Las siguientes variables: altura de planta, número de hojas por planta, peso verde y seco de la parte aérea de la planta, peso verde y seco de la raíz, y número de frutos por planta mostraron valores más altos en el sistema de producción convencional a base de sustrato con arena al 100% y solución nutritiva inorgánica. El rendimiento en seco y la calidad del fruto (diámetro polar, ancho de la cavidad y grosor de pulpa) fueron mayores en el sistema de producción orgánico a base de compost y aplicaciones de Azospirillum. Se puede concluir que los genotipos de chile Huacle, el genotipo negro, se adaptaron de manera favorable al sistema de producción orgánico con dosis de 20% de compost y aplicaciones de Azospirillum.

El girasol (Helianthus annuus L.) es una planta herbácea de la familia asterácea de gran importancia agrícola a nivel comercial por su atractiva inflorescencia y por su grande variedad de colores que van de amarillo clásico al anaranjado intenso y rojo, así mismo con su belleza al seguir al sol durante su desarrollo floral, convirtiendo el cultivo de girasol en una planta de gran valor ornamenta. El objetivo del estudio fue evaluar el comportamiento fenotípico y agronómico de 8 variedades de “Helianthus annus” en el cantón Machala. El trabajo se realizó en el cantón Machala, El Oro, realizando dos siembras del cultivo, la primera en el periodo de agosto a noviembre de 2020 y la segunda en diciembre del mismo año a marzo de 2021, se cultivaron las variedades de girasol: Sunbright o Sunbeam, Moulin Rouge, Sunspot o Big Smile, Russian Giant, Velvet Queen, Common Sunflorwer, Music Box o Pastiche y Moonwalker, se evaluaron 19 variables morfoagronómicas en el transcurso de su desarrollo, las que se caracterizaron mediante técnicas de análisis de crecimiento y las variables de rendimiento, se estimaron por medio de cantidad y peso de capítulos y semillas. Los principales resultados indican que las 8 variedades de girasol presentaron un comportamiento agromorfológico heterogéneo en la primera siembra, mientras que en la segunda hubo un cambio significativo en su comportamiento agromorfológico, evidenciando el efecto del ambiente en la expresión del fenotipo, en ambas siembras.

Quinoa (Chenopodium quinoa Willd.) is a crop with high nutritional and agronomic potential, adapted to environmental stress conditions. It is grown on a small scale in Mexico, and currently improved varieties are not available. In order to establish the basis to guide genetic improvement in Mexico, the objective was to determine the genetic variability, heritability and interrelationships of yield and its components in 16 quinoa genotypes, in a randomized complete block design, in six environments in the central high valleys of Mexico. The proportion of participation of the sources of variation genetic, environmental, and genotype × environment interaction was determined; as well as heritability, response to selection, and phenotypic correlations among morphological characters, yield and its components. Out of 15 variables evaluated, the genetic effects on thousand-grains weight and grain filling period were the most important; whereas for plant height at flowering, harvest index, and stem diameter, environmental effects were the most relevant. The genotype × environment interaction is not greater than 20 % for the 15 variables evaluated. The highest values for additive variance, heritability, and response to selection were for grains per square meter, yield, thousand-grains weight, grain filling period, and panicle emergence. The variables stem diameter, plant height at maturity, grains per square meter, yield per day, grain filling period, and panicle emergence were the most correlated with yield. Therefore, they can be used as indirect yield selection criteria in breeding programs to obtain materials with better agronomic characteristics. Based on the genetic parameters obtained and the association of the variables with yield, grains per square meter, yield per day and plant height at maturity are the most appropriate traits for indirect selection for yield. [ABSTRACT FROM AUTHOR]

In the "Scientific and Technological Base Unit" (UCTB), belonging to the National Institute of Agricultural Sciences (INCA), a new rice cultivar was obtained through hybridizations. Its characteristics include its earliness, compact panicles, high number of grains per panicle and good agricultural yields, combined with tolerance to the main pests. Its behavior has been validated in areas of small producers of Cooperative Sector and in cultivar gardens for participatory varietal selection. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas is the property of Universidad de Santiago de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: C. albicans is recognized as the most virulent species of the genus and represents the major cause of candidiasis in humans. At the taxonomic level, C. albicans is classified as a complex of closely related species that includes C. albicans sensu stricto (s.s), C. dubliniensis, and C. africana. Objective: to identify the species of the C. albicans complex isolated from different samples of patients from the fifth region of Valparaíso. Materials and method: 103 strains of the C. albicans complex were identified, isolated from superficial and deep samples during the year 2020. The identification was carried out based on morphophysiology and the amplification of the HWP1 gene. Results: 100 strains were identified as C. albicans s.s, 2 as C. dubliniensis and 1 as C. africana. Within the strains identified as C. albicans s.s, 4 patterns of fragment sizes were observed. Conclusions: C. albicans s.s was the most frequent species and based on the HPW1 genotype, four patterns are described (H1 to H4). [ABSTRACT FROM AUTHOR]

Objetivo. Determinar el efecto del grupo genético sobre algunas características físico químicas asociadas a la calidad de carne en lomos (Longissimus thoracis) de ovinos de pelo del sureste mexicano. Materiales y métodos. Se evaluaron corderos machos del genotipo Dorper (Dp,n=6), Katahdin (Kt,n=6) y la cruza F1 semental Dorper x madres Katahdin (DpxKt,n=6), sacrificados con un peso promedio de 29.5±4.2 kg, a una edad de 6.2±0.2 meses. Las muestras L. thoracis fueron analizadas para determinar su composición proximal y sus características físicas. Resultados. El grupo genético no tuvo efecto (p>0.05) sobre % de humedad, % proteína cruda (%PC) y el contenido de mioglobina, por el contrario, afectó (p

Objective. To quantify some meat quality physicochemical traits in Longissimus thoracis from hair sheep in southeast Mexico, and test if any of these traits effectively distinguish between genotypes. Materials and methods. Animals were 18 male lambs from the Dorper (Dp, n=6) and Katahdin (Kt, n=6) breeds, and F1 Dorper sire x Katahdin dam (DpxKt, n=6) crosses. They were slaughtered at 29.5 ± 4.2 kg average weight, at 6.2 ± 0.2 months. Proximate composition and physicochemical analyses were run of Longissimus thoracis samples, and a canonical discriminant analysis run to identify traits that distinguished between breeds. Results. Genetic group had no effect (p>0.05) on moisture (%), crude protein (% CP) and myoglobin content. It did affect (p<0.05) intramuscular crude fat (% IMF), ash (%) and cholesterol content. IMF (4.05%) and cholesterol (92.63 mg/100 g) were highest in Kt. Ash content (1.01%) was lowest in DpxKt. Values for pH did not differ between genetic groups and were within normal limits. Cooking and drip losses were highest in DpxKt. Chroma, L* and a* values were highest in Kt, providing fresh meat from this genotype a desirable bright red color. The distinction analysis identified drip loss, IMF, Chroma and a* as effectively separating the genotypes. Conclusions. Genetic group influenced intramuscular fat, cholesterol and ash contents, and four traits served to distinguish between genotypes. These are important data for producers and marketers as they aim to create fresh meat products with specific meat quality physicochemical traits that meet demand in a diversifying market that includes grilling and gourmet cuts. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to evaluate agronomic indicators and estimate genetic parameters, six tomato cultivars were established in two locations, using a randomized complete block design with four replications. Eight morphoagronomic variables were evaluated, including agricultural yield. The data were processed with the Statistica statistical package, which was used to perform two-factor analysis of variance, double classification and random effects, the latter to decompose the total phenotypic variance. Multiple comparison of means was performed through Tukey's test p≤0.05. Simple correlation analysis was also performed among the variables evaluated. The results showed significant effects of genotype-environment interaction in 75 % of the variables under study. Coefficients of environmental variation were high for all traits and heritability estimates, in a broad sense, were very low. Simple correlations were high and positively significant between the characters fruit mass per plant and fruit number per plant, fruit diameter and fruit mass per plant, yield and fruit number per plant, yield and fruit mass per plant, and yield and fruit diameter. [ABSTRACT FROM AUTHOR]

Copyright of Revue d'élevage et de Médecine Vétérinaire des pays Tropicaux is the property of CIRAD and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Drought stress consists of a significant productivity constraint in tomatoes. Two contrasting crosses were performed to estimate physiological and morphological traits in response to drought stress during the vegetative stage, aiming to identify superior genotypes for drought tolerance. Two genotypes (GBT_2037 - sensitive drought-sensitive and GBT_2016 - intermediate drought-tolerant) were used as female parentals, and a commercial hybrid (drought tolerant) was used as a pollen source in both crosses: C1 (GBT_2037 x Commercial hybrid) and C2 (GBT_2016 x Commercial hybrid). The populations of parentals (P), the first generation of descendants (F1), backcrosses (BC), and the second generation of self-pollination (F2) were exposed to drought stress for 20 days when they were analyzed: physiological traits (relative water content of leaves, proline, and relative chlorophyll content) and morphological (plant height, stem diameter, number of leaves, fresh and dry matter of roots and shoot and classification by wilt scale). The means of chlorophyll, root/shoot ratio, and water content in leaves for the F2 generation of C2 were higher than C1, indicating that C2 resulted in plants with greater capacity to maintain turgor under conditions of water stress and presented minor damage to the photosynthetic structures, consequently showing greater tolerance to drought stress. [ABSTRACT FROM AUTHOR]

En el valle de Apatzingán, Michoacán, México, se cultiva la papaya (Carica papayaL.) Maradol Roja, sin embargo, al tener una producción monovarietal, los productores se enfrentan a un riesgo latente en relación con la sanidad del cultivo y la comercialización en un mercado complejo. Ante ello, el objetivo de esta investigación fue evaluar agronómicamente el desarrollo y la fructificación de tres genotipos de papaya en el ejido El Platanal, municipio de Tumbiscatio, Michoacán, México, para determinar su adaptabilidad como alternativa de producción. Las variables evaluadas fueron: altura de planta, diámetro de tallo, frutos por planta, frutos hermafroditos elongados, frutos pentandrios, altura del primer fruto y hojas por planta. El diseño experimental utilizado consistió en bloques aleatorizados, tres repeticiones por bloque (uno por genotipo) y 20 plantas por bloque con tres hileras. Las comparaciones entre medias se hicieron con la prueba Tukey (p < 0,05). Los resultados indicaron que el híbrido Siluet presentó plantas con más de 3 m de altura, la variedad Maradol Roja 2,45 m y el híbrido Amarela 2,32 m. El número total de frutos por planta difirió estadísticamente entre los genotipos: Siluet tuvo 56,93, Maradol Roja 40,82 y Amarela 34,86. La altura del primer fruto para Maradol Roja y Amarela fue de 0,86 y 0,84 m, respectivamente, los cuales resultaron estadísticamente similares. Se concluye que MaradolRoja, Amarela y Siluet comprobaron tener buen potencial de adaptabilidad a esta región, de manera que los híbridos se constituyen en materiales alternativos a la tradicional variedad Maradol Roja.

Introducción. Rhynchophorus palmarum es la plaga de mayor importancia económica del cocotero en México. Objetivos. i) Determinar la captura de R. palmarum en cinco tipos de trampas. ii) Estimar el costo anual y el costo-beneficio de la captura en los cinco tipos de trampas. iii) Comparar la captura entre dos huertas con diferente genotipo [variedad “Alto Pacífico Ecotipo 2” (AP) e híbrido “Enano Verde de Brasil” (HEVB)]. iv) Correlacionar la captura con los factores ambientales. Métodos. Se monitoreó durante un año en dos genotipos y se contabilizó semanalmente la captura hembras, machos y total. Se determinó el costo de trampeo y costo beneficio en los cinco tipos de trampas. Con datos climáticos y de captura se realizaron correlaciones. Resultados y discusión. En AP se capturaron 3 414 insectos, donde la TBB (Trampa bote de basura) y CSAT (Colegio Superior de Agricultura Tropical) fueron las más efectivas (F=4.084, P

Drought stress consists of a major productivity constraint in tomato. Two contrastant crosses were performed to estimate physiological and morphological traits involved in the response to drought stress during vegetative stage, aiming to identify superior genotypes for drought tolerance. Two varieties (GBT_2037 – drought sensitive and GBT_2016 – intermediate drought tolerant) were used as female parentals and a commercial hybrid (drought tolerant) was used as a pollen source in both crosses: C1 (GBT_2037 × Commercial hybrid) and C2 (GBT_2016 × Commercial hybrid). The populations of parentals (P), first generation of descendants (F1) and second generation of self-polination (F2) were exposed to drought stress during 20 days, when they were analysed: physiological traits (relative water content of leaves, proline and relative chlorophyll content) and morphological (plant height, stem diameter, number of leaves, fresh and dry matter of roots and shoot and a classification by wilt scale). The means of chlorophyll, root/shoot ratio and water content in leaves for the F2 generation of C2 were higher than C1, indicating that C2 resulted in plants with greater capacity to maintain turgor under conditions of water stress and presented less damage on the photosynthetic structures, consequently showing greater tolerance to drought stress.

Resumo O alto valor nutricional e o baixo custo de comercialização têm impulsionado o consumo de raízes de batata-doce. Adicionalmente, a grande variabilidade genética levanta questionamentos sobre a qualidade pós-colheita dos acessos cultivados. Assim, o presente estudo objetiva caracterizar e avaliar as características físico-químicas e os compostos bioativos de raízes de batata-doce. Os tratamentos consistiram na avaliação de 11 acessos (UGA 34, UGA 37, UGA 49, UGA 73, UGA 76, UGA 81, UGA 110, UGA 125, UGA 126, UGA 127 e Parcela 49). Os atributos físico-químicos de firmeza (FI) e massa seca (MS) foram avaliados em delineamento experimental em blocos casualizados. Avaliaram-se ainda pH, teor de sólidos solúveis (SS), acidez titulável (AT), relação entre sólidos solúveis e acidez titulável (SS/AT), e parâmetros colorimétricos L*, saturação de cor croma e tonalidade da cor pelo ângulo Hue obtidos da casca (externa) e da polpa (interna) das raízes. Avaliou-se também a concentração de compostos bioativos: carotenoides totais (CAR), compostos fenólicos (FEN) e teor de ácido ascórbico (AA), além da capacidade antioxidante hidrofílica e lipofílica (CAH e CAL) de amostras de batata-doce congelada. As análises foram realizadas em triplicata sob delineamento inteiramente casualizado. Os resultados indicaram grande variabilidade entre os acessos estudados, com maior rendimento de raízes de UGA 125 e UGA 127. Os acessos UGA 126 e UGA 34 sobressaíram-se quanto aos teores de sólidos solúveis, à capacidade antioxidante hidrofílica e lipofílica, à firmeza e à matéria seca; seus parâmetros colorimétricos também se destacaram dos demais acessos. Os acessos UGA 73 e UGA 81 apresentaram maiores teores de compostos fenólicos. Dessa forma, identificou-se o potencial produtivo dos acessos estudados que nos permite indicar os acessos mais promissores ao cultivo e ao consumo.

Introducción. El papayo es la tercera fruta tropical de mayor importancia a nivel mundial. Sin embargo, en la variedad silvestre, endémica de Cuba, no existen evidencias de estudios para su conservación, cultivo o programas de mejoramiento. Objetivo. Evaluar especímenes de papayo silvestre de la cuenca Almendares-Vento, con el empleo de descriptores morfoagronómicos, para contribuir a la conservación y valorar su potencial productivo y de caracteres de interés para el mejoramiento genético de C. papaya. Materiales y métodos. La investigación se desarrolló entre 2008 y 2018, in situ, en la Cuenca Almendares-Vento, Mayambeque, y condiciones tradicionales de cultivo, en el Instituto Nacional de Ciencias Agrícolas, San José de Las Lajas, Cuba. Las evaluaciones se realizaron mediante dieciséis descriptores morfoagronómicos recomendados para la especie. En el 2016 se colectaron semillas de once plantas para su evaluación individual ex situ. Los descriptores cualitativos se describieron mediante imágenes fotográficas y para los cuantitativos in situ se calcularon los estadígrafos descriptivos de cada una de las variables evaluadas. Para las evaluaciones ex situ se realizó un análisis de componentes principales y un biplot. A cada descriptor se le realizó intervalos de confianza al 95 %. Resultados. In situ la población de papayo silvestre estaba constituida por especímenes que habitaban aislados y distantes unos de otros. En condiciones de cultivo tradicional mostraron variabilidad morfoagronómica en el número de frutos y sus dimensiones, los °Brix y la acidez. Además de su valor ecológico, los caracteres antes mencionados revelaron cualidades potenciales en la identificación de genotipos promisorios, relacionados con el mercado y empleo en el mejoramiento del cultivo. Conclusión. Los frutos presentaron propiedades físicas y bromatológicas que convierten al papayo silvestre en un recurso fitogenético promisorio, para su empleo en el mejoramiento del cultivo y como una alternativa de producción en condiciones tradicionales.

La papa (Solanum tuberosum) es uno de los cultivos más importantes en la alimentación de la población mundial, después del arroz, el maíz y el trigo. La principal limitante del cultivo a nivel mundial es el tizón tardío (Phytophthora infestans) que puede ocasionar la pérdida total si no se realiza un manejo adecuado y oportuno. P. infestans muta permanentemente, apareciendo razas nuevas y más agresivas, por el uso indiscriminado de fungicidas y la dispersión mundial del cultivo, donde hay diferentes condiciones ambientales, de suelo y de manejo agronómico. Una estrategia para su control es el manejo integrado de la enfermedad, donde el mejoramiento genético es pilar fundamental. El presente estudio evaluó la resistencia genética de variedades mejoradas, nativas y clones del programa de mejoramiento de INIAP Ecuador a través de los componentes de resistencia: 1) área de la lesión (AL), 2) tasa de crecimiento de la lesión (TCL), 3) periodo de latencia (PL), 4) intensidad de esporulación (IE) y 5) período de incubación (PI). Los genotipos estudiados presentaron una gran variabilidad en la resistencia expresada en sus componentes, así: AL estuvo comprendido entre 0 y 111,50 mm2; TCL presentó un rango entre 0 y 4,69 mm/día; PL obtuvo valores desde 5 hasta 10 días; IE, desde 0 hasta 3, y PI, entre 2 y 8 días. En este estudio, la TCL fue el componente que más discriminó los materiales con resistencia, lo que está acorde con estudios similares. Este componente puede utilizarse para seleccionar genotipos resistentes en fases iniciales y los genotipos con características de resistencia podrían ser utilizados como progenitores en un programa de mejoramiento genético.

Prolonged storage of seeds may lead to decreases in seed quality, negatively affecting germination and vigor and preventing the obtaining of a promising stand. Seed quality is a critical factor, and the performance of the lot can be altered by vigor, dormancy and, mainly, by the time and conditions in which the seeds were stored. In the experiment, the physiological quality of seeds 14 genotypes of buffel grass (Cenchrus ciliaris L.) genotypes stored for a period of thirteen years in cold conditions was evaluated. The seeds were subjected to germination induction treatment with potassium nitrate (KNO3) and evaluated to identify seeds with presence and absence of embryos. The seed storage period affected their germination capacity and the use of KNO3 did not increase seed germination. A low number of full seeds was found for genotype 613 (12%). The relative germination percentages did not underestimate the buffel grass seed germination potential, as it is usually calculated, providing an improved distinction between the evaluated genotypes. The use of KNO3 increased the seedling root and shoot weights of some genotypes, as well as the dry matter weight of seedlings, an important characteristic for forage production. The prolonged storage affects the physiological quality of buffel grass seeds. The production of seeds without embryo is a problem found for this species, which affects the final quality of the seed lots produced. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Terra Latinoamericana is the property of Sociedad Mexicana de la Ciencia del Suelo A.C. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ginecología y Obstetricia de México is the property of Federacion Mexicana de Ginecologia y Obstetricia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

O presente trabalho objetivou avaliar o efeito de diferentes substratos e tamanhos de vasos na produção de mudas por estaquia de dois genótipos da espécie Melochia pyramidata. Para a avaliação em diferentes substratos utilizou-se o DIC (Delineamento inteiramente casualizado) em esquema fatorial 3 x 2, com 3 tipos de substratos (areia, substrato comercial Plantmax® e areia + esterco) e 2 genótipos (MP1 e MP2.) com 5 repetições. Para a avaliação feita em diferentes tamanhos de vasos, utilizou-se o esquema fatorial 2 x 2, com 2 tamanhos de vasos (V1: 1,8 Litros e V2: 0,9 Litros), 2 genótipos (MP1 e MP2) e 4 repetições. As avaliações iniciaram-se após sete dias do plantio das estacas nos tubetes, e continuaram, semanalmente, por dois meses, avaliando o número de brotações e o número de folhas. Após os dois meses estas mudas foram transplantadas para vasos, onde se avaliou número de brotações, número de folhas, número de frutos, número de botões florais, largura da folha e comprimento da folha. Os dados foram submetidos à análise de variância, com posterior agrupamento das médias pelo teste de Tukey, a 5% de probabilidade. As estacas de M. pyramidata apresentaram um bom desenvolvimento em areia lavada e substrato comercial Plantmax®, no entanto se recomenda a utilização da areia por apresentar menor custo para a produção de mudas. Ambos os genótipos se desenvolveram melhor em vasos de 1,8 Litros, com maiores quantidades de folhas, botões florais e frutos.

With the introduction of rotavirus vaccines Rotarix (RV1) or RotaTeq (RV5) in the immunization programs of an increasing number of countries, there is concern that the immune selec­tion pressure induced will cause an increase in the prevalence of virus genotypes not included in the vaccine formulation, or to the appearance of novel rotavirus strains that could evade the protective immune response. The natural fluctuation of rotaviruses makes it difficult to distinguish if the change in the circulating strains is due to the vaccine selective pressure or to the natural diversity fluctuation of viruses. If there has been a selective pressure, it has been low so far. However, it is important to keep an epidemiological surveillance and pay attention to the emergence of strains that are resistant to the vaccine, in particular in those countries where the viral diversity has been shown to be higher.

Introducción. La caracterización de cultivares de Rubus spp. tolerantes al estrés hídrico en campos experimentales es complicado por la dificultad de controlar los factores externos del medio ambiente donde son instalados. La inducción de estrés in vitro es una herramienta eficiente para estudiar los mecanismos de respuesta de las plantas y se emplea en los programas de mejoramiento para la selección de genotipos tolerantes al estrés hídrico. Objetivo. Evaluar la respuesta morfológica y fisiológica in vitro de los explantes en tres cultivares y la accesión silvestre de Rubus spp. bajo condiciones de estrés hídrico simulado con manitol. Materiales y métodos. El estudio se realizó en el Laboratorio de Biología de la Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas, Perú, durante el año 2020. Se empleó un diseño completamente al azar con arreglo factorial (Factor A: cuatro genotipos y Factor B: potenciales hídricos simulados con manitol: 0, -0,2, -0,3 y -0,4 MPa) y cuatro explantes por unidad experimental. Resultados. Los cultivares respondieron de manera distinta bajo estrés hídrico simulado con manitol. Los cultivares Navaho y Tupy registraron mayor tolerancia. Conclusión. Los rasgos morfológicos y fisiológicos relacionados con la longitud de raíz, el contenido hídrico de brote, raíz y hoja permitieron identificar cultivares de Rubus spp. tolerantes al estrés hídrico simulado con manitol en la fase vegetativa.