Examinando por Materia "Virus"

Mostrando 1 - 5 de 5

Control interno de calidad en el cultivo de papa
(Instituto Nacional de Innovación Agraria - INIA, 1999-05) Cabrera Hoyos, Héctor Antonio; Pando Gomez, Rosmeri Verónica
El cultivo de papa esta siempre expuesta a plagas y enfermedades, muchas de ellas pueden ser controladas durante la misma campaña, otras permanecen en la semilla y son llevadas así de un campo a otro, de una campaña a otra; de estas enfermedades los virus son las más importantes, para las cuales no hay en la actualidad un método para eliminarlas del campo y estos conducen a una declinación del potencial productivo de la papa a través de la campaña como DEGENERACIÓN DE LA SEMILLA. Para lo cual contamos con un Laboratorio de Control Interno de Calidad, para realizar los análisis respectivos.
First report of cassava common mosaic disease and Cassava Common Mosaic Virus infecting cassava (Manihot esculenta) in Peru
(American Phytopathological Society, 2017-04-03) Fernandez Huaytalla, Elizabeth; Espinoza, Ivonne; Lozano, Ivan; Bolaños, Carmen; Carvajal Yepes, Monica; Cuellar, Wilmer
Cassava common mosaic disease (CCMD) can cause root yield losses of approximately 30% (Venturini et al. 2016) in cassava (Manihot esculenta Crantz) and it has already been reported in Brazil, Colombia, Paraguay, and Argentina (Calvert et al. 2012; Di Feo et al. 2015). Most of Peru’s cassava production is in the eastern side of the country (the rainforest region) and is mainly used for direct human consumption. Cultivated area in these regions is approximately 48.1 thousand hectares (MINAGRI 2015). CCMD is caused by Cassava common mosaic virus (CsCMV; Calvert et al. 1996), a mechanically transmitted potexvirus that can be disseminated via infected stem cuttings used for cassava propagation. Given the presence of the disease in neighboring countries, a field survey for virus diseases in cassava was organized during June 2016 in the province of Huaral, in the central coast of Peru, where typical leaf mosaic and leaf deformation symptoms associated to CCMD were observed in local cassava varieties. To verify the presence of CsCMV and CCMD in Peru, the youngest leaves of four plants showing virus-like symptoms and four plants not showing symptoms were collected from one of the affected fields and dried in silica gel for analysis. Double antibody sandwich (DAS)-ELISA tests using a polyclonal antiserum readily detected CsCMV in all symptomatic samples (Nolt et al. 1991). In addition, mechanical transmissions to the experimental host Nicotiana benthamiana induced typical systemic leaf mosaic. RT-PCR tests targeting the replicase region of CsCMV were carried out using primers CsCMV-3269-F: 5′-GAGGCTCTTCTCTGGGAAAC-3′ and CsCMV-3896-R: 5′-CTTGAGTCCAGTTTGATGTC-3′, designed using an alignment of CsCMV-related sequences available in GenBank. An expected PCR fragment of 627 bp was obtained only in samples showing symptoms of CCMD. RT-PCR tests for other cassava-infecting viruses reported in the Americas (Carvajal-Yepes et al. 2014) were negative in these samples. PCR products from two independent CsCMV-positive samples were sent for direct Sanger-sequencing (Macrogen, Korea). CsCMV sequence isolates from Peru (GenBank accession nos. KX964625 and KX964626) show a nucleotide identity of 88 to 93%, and an amino acid sequence identity of 99% with other CsCMV sequences available in GenBank, and phylogenetic analysis clustered Peruvian isolates with CsCMV sequences reported in cassava. These results stress the need to implement surveillance activities and quick diagnostic protocols, as the inadvertent propagation and accumulation of virus infections could cause an increasingly negative effect on cassava and other vegetatively propagated crops.
La importancia de los virus en el cultivo de la vid
(Instituto Nacional de Innovación Agraria - INIA, 2014-06) Barrera Rojas, Ciro
Describe la importancia de los virus en el cultivo de vid: los daños que causan, detección y diagnosis, recomendaciones para superar los daños causados y ventajas del uso de plantones libres de virus.
Micropropagación de plantas de camote (Ipomoea batatas L.) libres de virus
(Instituto Nacional de Innovación Agraria - INIA, 2010-09) Olivera Soto, Julio A.; Marcelo C., Filomena
Esta publicación describe el protocolo para la micropropagación de plantas camote (Ipomoea batatas L.) libres de virus desarrollado a partir de los trabajos de investigación realizadas en el Laboratorio de Cultivo de Tejidos Vegetales del Instituto Nacional de Innovación Agraria en la Estación Experimental Agraria Donoso.
The honeybee (Apis mellifera) developmental state shapes the genetic composition of the deformed wing virus-A quasispecies during serial transmission
(Springer Nature, 2020-04-06) Yañez, Orlando; Chávez Galarza, Julio César; Tellgren Roth, Christian; Pinto, María Alice; Neumann, Peter; R. de Miranda, Joachim
The main biological threat to the western honeybee (Apis mellifera) is the parasitic mite Varroa destructor, largely because it vectors lethal epidemics of honeybee viruses that, in the absence of this mite, are relatively innocuous. The severe pathology is a direct consequence of excessive virus titres caused by this novel transmission route. However, little is known about how the virus adapts genetically during transmission and whether this influences the pathology. Here, we show that upon injection into honeybee pupae, the deformed wing virus type-A (DWV-A) quasispecies undergoes a rapid, extensive expansion of its sequence space, followed by strong negative selection towards a uniform, common shape by the time the pupae have completed their development, with no difference between symptomatic and asymptomatic adults in either DWV titre or genetic composition. This suggests that the physiological and molecular environment during pupal development has a strong, conservative influence on shaping the DWV-A quasispecies in emerging adults. There was furthermore no evidence of any progressive adaptation of the DWV-A quasispecies to serial intra-abdominal injection, simulating mite transmission, despite the generation of ample variation immediately following each transmission, suggesting that the virus either had already adapted to transmission by injection, or was unaffected by it.