Chili pepper is one of the main crops of economic importance in Mexico, and Fusarium wilting is a disease that limits its production. In addition, the inappropriate use of agrochemicals in farming activities generate environmental and health problems. Therefore, in this study the effectiveness of Streptomyces sp PRIO41 was evaluated as a (1) biocontrol agent of Fusarium spp and (2) plant growth promoter bacteria. Assays of pathogenicity and virulence of Fusarium spp. in jalapeño pepper seeds, and interactions of these pathogens with Streptomyces PRIO41 were evaluated under two nutritional conditions. In the greenhouse, the effectiveness of Streptomyces sp. PRIO41 was determined as a (1) biocontrol of Fusarium, and (2) plant growth promoter of wilt of pepper plants. The results showed that all fungal isolates caused symptoms in pepper seeds and seedlings with different degrees of virulence. Interactions in vitro showed that Streptomyces showed the most effective range of virulence against Fusarium isolates in the poor medium (37.6%-100%), with fungicidal effects in some cases. In the greenhouse, Streptomyces PRIO41 reduced Fusarium wilting up to a 40%, and positively affected all vegetative growth parameters, particularly plant height, leaf area, root length, and leaf and root dry biomasses. This study showed the potential of Streptomyces PRIO41 as a biocontrol agent of Fusarium spp., and as a biofertilizer of pepper plants.

El chile es uno de los principales cultivos de importancia económica en México, y la marchitez causada por Fusarium es una de las enfermedades que limitan su producción. Además, el uso inadecuado de los agroquímicos en el cultivo generan problemas ambientales y de salud. Por ésto, en este estudio se evaluó la efectividad de Streptomyces sp. PRIO41 como agente de biocontrol de Fusarium spp. y como promotor del crecimiento de plantas de chile. Para ello, se determinó in vitro la patogenicidad y virulencia de Fusarium spp. en semillas de chile jalapeño, así como la interacción de los aislados fúngicos con Streptomyces sp. PRIO41 bajo 2 condiciones nutricionales. Finalmente, en invernadero se evaluó la efectividad de Streptomyces PRIO41 como (1) biocontrol de la marchitez causada por Fusarium, y (2) promotor del crecimiento de plantas de chile. Los resultados mostraron que todos los aislados fúngicos causaron sintomatología en semilla y plántulas de chile con diferentes grados de virulencia. En las interacciones in vitro, Streptomyces mostró el rango de mayor efectividad respecto a aislados de Fusarium en el medio pobre en nutrientes (37,6%-100%) con efectos fungicidas en algunos casos. En invernadero, Streptomyces PRIO41 redujo la marchitez causada por Fusarium hasta en un 40% y afectó positivamente todos los parámetros de crecimiento vegetativo, particularmente altura de planta, área foliar, longitud de raíz, y biomasa seca foliar y radical. Este estudio muestra el potencial de Streptomyces PRIO41 como agente de control biológico de Fusarium spp. y como biofertilizante en plantas de chile.

The present study aimed to detect BoHV-1 and BoHV-5 latent infections in Uruguayan beef cattle. Trigeminal ganglia (TG) were collected from 62 cattle heads in a slaughterhouse. Viral genomes were detected by a type-differential nested PCR (nPCR) targeting the UL44 gene of BoHV-1 and BoHV-5. Viral DNA was detected in 64.5% (40/62) of the animals. Thirty cattle heads (48.4%) contained only BoHV-1 DNA, whereas nine (14.5%) contained DNA of both BoHV-1 and BoHV-5. One cattle head (1.6%) contained BoHV-5 DNA only. Detection of neutralising antibodies was performed on sera of the examined cattle heads by a standard serum neutralization test. Neutralising antibodies were detected in 16 of the viral DNA-carrying animals, corresponding to 40% of the samples from which viral genomes were identified. The type-specific genomic prevalence was substantially different from that reported in a similar study carried out in Brazil and may be associated to the predominant European type of breeds farmed in Uruguay, as opposed to Brazilian cattle which is often crossbred (Bos Taurus x Bos indicus). Therefore, despite both BoHV-1 and BoHV-5 do circulate in Uruguay and sometimes both viruses can co-infect cattle, BoHV-5 infections seem less frequent than BoHV-1 infections.

El presente estudio tuvo como objetivo detectar la presencia de BoHV-1 y BoHV-5 en infecciones latentes de ganado vacuno en el Uruguay. Se analizaron 62 muestras de ganglios trigéminos (TG) de cabezas de bovinos colectados en un frigorífico. Utilizando un tipo diferencial de PCR (nPCR) focalizando en el gen UL44 de BoHV-1 y BoHV-5 se detectaron los diferentes genomas virales. ADN viral fue detectado en 64,5% (40/62) de los animales. Treinta muestras (48,4%) contenían solo el ADN de BoHV-1, mientras que nueve (14,5%) contenían ADN de ambos BoHV-1 y BoHV-5. Una sola muestra (1,6%) contenía apenas ADN de BoHV-5. La detección de anticuerpos neutralizantes se realizó en los sueros mediante la técnica de seroneutralización in vitro. Anticuerpos neutralizantes fueron encontrados en 16 de los animales portadores de ADN viral, lo que corresponde a 40% de las muestras con genoma viral identificado. La prevalencia genómica específica del tipo viral fue sustancialmente diferente de la que se informó en un estudio similar llevado a cabo en Brasil y puede estar asociada con el tipo de razas europeas predominante criadas en Uruguay, en contrapartida a los bovinos brasileños que son cruzados (Bos taurus x Bos indicus). Sin embargo, y a pesar de que tanto BoHV-1 y BoHV-5 pueden ser causas de coinfecciones ocasionales en Uruguay, BoHV-5 mostró una significativa menor prevalencia comparado con BoHV-1.

Adenovírus (AdV), enterovírus (EV), rotavírus (GARV) e Torque teno vírus (TTV) são vírus não envelopados, excretados nas fezes, podendo, assim, contaminar corpos hídricos. No presente estudo, a detecção molecular desses agentes foi realizada em amostras de águas superficiais provenientes do Arroio Dilúvio, o qual cruza a cidade de Porto Alegre-RS, Brasil. As amostras foram coletadas em três meses diferentes (janeiro, abril e setembro) do ano de 2009. A maior taxa de detecção viral foi observada para EV (64,28%), seguida por TTV (28,57%) e AdV (21,43%). Rotavírus não foi detectado. Foi verificada presença simultânea de dois grupos virais em cinco (35,71%) das 14 amostras analisadas. Janeiro foi o mês com a maior taxa de detecção viral, sendo todas as amostras, coletadas nesse mês, positivas para, no mínimo, um grupo viral em estudo. A correlação entre a detecção desses diferentes agentes virais e os fatores ambientais é discutida. Conforme conhecimento dos autores, essa é a primeira descrição de genomas virais em amostras de água provenientes do Arroio Dilúvio, Porto Alegre, Brasil.

Adenovirus (AdV), enterovirus (EV), genogroup A rotaviruses (GARV) and Torque teno virus (TTV) are non-enveloped viral agents excreted in feces and so may contaminate water bodies. In the present study, the molecular detection of these viruses was performed in samples of surface water collected from the Arroio Dilúvio, a waterstream that crosses the city of Porto Alegre, RS, Brazil, receiving great volumes of non-treated sewage from a large urban area. Sampling was performed during 2009, in three different occasions (January, April and September). The highest detection rate was observed for EV (64.28%), followed by TTV (28.57%) and AdV (21.43%). Rotaviruses were not detected. More than on kind of tested virus was detected in five (35. 71%) of 14 samples. January was the month with the highest viral detection rate, being all samples, collected in this month, positive for at least one group of tested virus. The correlation between the detection of these different viral agents and environmental factors is discussed. To the knowledge of the authors, this is the first description of viral genomes in water samples taken from the Arroio Dilúvio, Porto Alegre (Brazil).

This study presents the effect of Liquid Compost Factor (LCF) seed treatments on plant height in greenhouse trials, and plant density, plant height and seed yield of chickpea in field conditions. The greenhouse trials were organized in a randomized block design, while in field experiments were established in a factorial complete randomized block design conducted in Moscow and Genesee, Idaho, USA locations during 2003 and 2004. In the greenhouse, LCF 1:64 had the highest plant growth, and was statistically similar to LCF 1:110, LCF 1:128 and LCF 1:140, but different to the non-treated control. The orthogonal contrasts of LCF treatments vs non-treated control, LCF 1:64 vs LCF 1:110, and LCF 1:140 were significant, and LCF 1:64 vs LCF 1:128 was highly significant. In the first year of field experiments, LCF 1:64+Maxim+Apron had the highest plant density and seed yield followed by LCF 1:64 and LCF 1:128 in both locations. In the second year of field trials, LCF 1:128 and Apron had the greatest plant density; LCF 1:64 and LCF 1:128+Maxim were the best for plant height; and LCF 1:128+Apron showed the best seed yield in Moscow, while in Genesee LCF 1:64+Maxim was the best for plant density followed by LCF 1:128, LCF 1:128 and their combinations; LCF 1:128, LCF 1:64+maxim+Apron and LCF 1:64 had the greatest effect on plant height; and LCF 1:64, Apron+Maxim and Apron had the greatest seed yield. LCF seed treatments significantly increased plant density, plant height and seed yield of chickpea showing the potential of LCF to be used alone or in combination with Apron or Maxim as plant growth regulator.

Este estudio muestra el efecto del tratamiento de semilla con Factor de Composta Líquida (LCF) sobre la densidad de planta, altura de la planta y rendimiento en garbanzo en condiciones de campo. Los experimentos de invernadero fueron organizados en un diseño de bloques al azar, mientras que los de campo fueron establecidos en un arreglo factorial en bloques al azar realizado en las localidades de Moscow y Genesee, Idaho, USA durante 2003 y 2004. En el invernadero, LCF 1:64 presentó una mayor densidad de planta, similar a LCF 1:110, LCF 1:128 y LCF 1:140 pero diferente al control. Los contrastes ortogonales de los tratamientos de LCF vs el control, LCF 1:64 vs LCF 1:110, y LCF 1:140 fueron significativos y LCF 1:64 vs LCF 1:128 fue altamente significativo. En el primer año de estudio en campo, LCF 1:64+Maxim+Apron tuvo la mayor densidad de planta y rendimiento, seguido por LCF 1:64 y LCF 1:128 en ambas localidades. En el segundo año de estudio en campo, LCF 1:128 y Apron fueron superiores en densidad de planta; LCF 1:64 y LCF 1:128+Maxim mostraron una mayor altura de planta; y LCF 1:128+Apron tuvo un mayor rendimiento en la localidad de Moscow. En Genesee, LCF 1:64+Maxim fue mayor en la densidad de planta, seguido por LCF 1:128, LCF 1:128 y sus combinaciones; LCF 1:128, LCF 1:64+maxim+Apron y LCF 1:64 mostraron una mayor altura de la planta; y LCF 1:64, Apron+ Maxim y Apron tuvieron el más alto rendimiento. Los tratamientos a la semilla con LCF incrementaron significativamente la densidad de planta, altura de la planta y el rendimiento de garbanzo, mostrando el potencial del LCF para ser empleado sólo o en combinación con Apron o Maxim como promotor de crecimiento de plantas.

In order to understand the temporal dynamics of actinomycete communities of the rhizosphere of the desert plant Artemisia tridentata (sagebrush), two complementary methods were used. They were: (1) 16S rDNA-based PCR coupled with denaturing gradient gel electrophoresis (DGGE), and (2) an agar plate enumeration methodology in which three different media were used to quantify total bacteria, actinomycetes, and fungi. The objective of this research were: (1) to obtain a comprehensive picture of the structure of actinomycete populations, and (2) their dynamics in the rhizosphere of young and old sagebrush plants during two distinct seasons. PCR-DGGE analysis showed that actinomycete groups were less diverse in rhizosphere soils collected in winter than in bulk soils. On the other hand, rhizosphere soil of A. tridentata young plants (RSYP) collected in spring showed an enrichment of actinomycete diversity and/or selection of unique actinomycete populations. This was not the case with the actinomycete populations detected in the rhizosphere soil of old plants (RSOP) in the same season. In this later case, a shift in the dominant bands on PCR-DGGE gels was observed between seasons. Finally, the enumeration analysis showed that actinomycete counts tended to be higher in spring, while total bacteria counts were higher in winter. Although strong soil type effects were detected, more research in the unexplored environment of sagebrush rhizosphere is necessary.

Para comprender la dinámica estacional de las comunidades de actinomicetos en la rizosfera de la planta desértica Artemisia tridentata (sagebrush), se emplearon dos métodos complementarios: (1) PCR basado en el DNAr 16S acoplado con electroforesis de geles con gradientes desnaturalizantes (DGGE), y (2) la metodología de enumeración en placas de agar en la cual se utilizaron 3 medios diferentes para cuantificar bacterias totales, actinomicetos y hongos. Los objetivos de esta investigación fueron: (1) obtener una mayor comprensión de la estructura de las poblaciones de actinomicetos, y (2) determinar su dinámica en la rizosfera de plantas de sagebrush jóvenes y viejas en dos estaciones del año. El análisis de PCR-DGGE mostró que los grupos de actinomicetos fueron menos diversos en suelos obtenidos en invierno asociados a la rizosfera en comparación a aquellos que no estaban asociados. El efecto de la rizosfera para enriquecer la diversidad de actinomicetos y/o selección de poblaciones únicas de actinomicetos fue observado en suelos de rizosfera de planta joven (RSYP) obtenidos en primavera; dicho efecto fue menor en suelos rizosféricos de plantas viejas (RSOP) de la misma estación. En este último tipo de suelo, se observó un cambio en las bandas dominantes en geles de PCR-DGGE entre estaciones. Finalmente, el análisis de plaqueo mostró que el número de actinomicetos fue mayor en primavera, mientras que el de las bacterias totales fue mayor en invierno. Aún cuando se detectó un fuerte efecto del tipo de suelo, se generó información relevante que urge más investigación en el ambiente inexplorado de la rizosfera de sagebrush.