Browsing by Autor "Orelvis Portal"

Now showing 1 - 12 of 12

An Efficient Method for the Extraction of High-Quality Fungal Total RNA to Study the Mycosphaerella fijiensis–Musa spp. Interaction
(Springer Science+Business Media, 2008) Aminael Sánchez‐Rodríguez; Orelvis Portal; Luís Rojas; Bárbara Ocaña; Milady Mendoza; Mayra Acosta; Elio Jiménez; Monica Höfte
An unwanted association: the threat to papaya crops by a novel potexvirus in northwest Argentina
(2022) Dariel Cabrera Mederos; Humberto Debat; Carolina Torres; Orelvis Portal; Margarita Jaramillo Zapata; Verónica Trucco; Ceferino Rene Flores; Claudio Ortiz; Alejandra Badaracco; Luis Acuña
Abstract An emerging virus isolated from papaya ( Carica papaya ) crops in northwestern (NW) Argentina was sequenced and characterized using next-generation sequencing. The resulting genome is 6,667-nt long and encodes five open reading frames in an arrangement typical of other potexviruses. This virus appears to be a novel member within the genus Potexvirus . Blast analysis of RNA-dependent RNA polymerase (RdRp) and coat protein (CP) genes showed the highest amino acid sequence identity (67% and 71%, respectively) with pitaya virus X. Based on nucleotide sequence similarity and phylogenetic analysis, the name papaya virus X is proposed for this newly characterized potexvirus that was mechanically transmitted to papaya plants causing chlorotic patches and severe mosaic symptoms. RT-PCR based detection of papaya virus X (PapVX) revealed that it is widely present in papaya crops from NW Argentina. The prevalence of PapVX, which seems to be restricted to the NW region of Argentina, and the fact that it has only been detected in this region could be associated with a recent emergence or adaptation of this virus to papaya in NW Argentina.
Biological control potential of two Beauveria bassiana isolates against the stink bugs Nezara viridula L. and Piezodorus guildinii Westwood (Hemiptera: Pentatomidae) in common bean
(Springer Nature, 2024) Yordanys Ramos; Orelvis Portal; Nicolai V. Meyling; Ingeborg Klingen
Abstract Background The stink bugs, Nezara viridula L. and Piezodorus guildinii Westwood (Hemiptera: Pentatomidae) are the most important and widespread species of polyphagous stink bugs in the tropical and subtropical regions of Latin America, which affect the quality and yield of the common bean ( Phaseolus vulgaris L.). The use of synthetic chemical insecticides is the major control strategy to manage stink bugs in common beans and alternatives are needed. In this study, mortality and median Lethal Time (LT 50 ) of two Cuban isolates of the entomopathogenic fungus Beauveria bassiana (18 S-O-R and 96 P-O-E), as well as one commercial Cuban isolate (Bb-18), at a concentration of 1 × 10 8 conidia/ml were evaluated. These evaluations were conducted against both stink bug species using Petri dish bioassays and a semi-field experiment in common beans. Results In Petri dish bioassays, the isolates 18 S-O-R and 96 P-O-E caused 100% mortality of both N. viridula and P. guildinii . This was significantly higher than for isolate Bb-18, which caused 86.3% N. viridula and 81.3% P. guildinii mortality. In the semi-field experiment, when pooling both stink bug species, total mortality after 14 days was 91.3% for 18 S-O-R, 80.0% for 96 P-O-E and 73.8% for Bb-18 isolates. LT 50 value for isolate 18 S-O-R tested under laboratory conditions was 6.04 ± 0.18 days for N. viridula and 5.32 ± 0.14 days for P. guildinii at the same concentration of 1 × 10 8 conidia/ml . LT 50 value for isolate 18 S-O-R in semi field was 6.79 ± 0.37 days for N. viridula and 7.71 ± 0.32 days for P. guildinii at 1 × 10 8 conidia/ml. Conclusion The study highlights the potential of B. bassiana 18 S-O-R as a promising candidate for control of stink bugs in common bean under tropical conditions as an alternative to conventional chemical insecticides in integrated pest management (IPM) programs. Moving forward, further research should focus on validating the efficacy under diverse field conditions and integrating application methods into practical IPM approaches. Future use of B. bassiana will enhance sustainability and reduce environmental impacts associated with pesticide use.
Daño a la membrana y respiración celular de Passalora fulva por extractos de hojas de Citrus aurantiifolia
(2019) Katia Ojito-Ramos; Daykenis Gonzáles-Hernández; Dianella Iglesias; Orelvis Portal
The foliar mold of tomato ( Solanum lycopersicum L.), produced by Passalora fulva , constitutes an important phytosanitary problem that affects the production of tomato in greenhouse. The use of plant extracts could contribute to the disease management. In this sense, ethanolic extracts of Citrus aurantiifolia leaves have shown antifungal activity against P. fulva . The aim of this study was to determine the effect of C. aurantiifolia extract on the cell membrane and respiration of P. fulva . The extract was obtained by ultrasound-assisted extraction and the content of total phenols was quantified. The effect of the extracts on the cell membrane was evaluated by determining the phosphorus and potassium concentrations in the extracellular medium and the effect in respiration for succinate dehydrogenase activity. The high concentrations of phosphorus and potassium in the extracellular medium suggested damage in the permeability of the cellular membrane of P. fulva . Similarly, the inactivity of the enzyme succinate dehydrogenase indicated an inhibition of cellular respiration of P. fulva by the extract evaluated. The results of this study confirmed the antifungal properties of the leaf extract of C. aurantiifolia . Keywords : action mode, leaf mould, lemon
Diversity and abundance of stink bugs egg parasitoids from organic and conventional fields in Cuba
(Springer Nature, 2024) Yordanys Ramos; Daniel Ricardo Sosa‐Gómez; Orelvis Portal
Endophytic establishment of Beauveria bassiana and Metarhizium anisopliae in maize plants and its effect against Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) larvae
(Springer Nature, 2020) Yordanys Ramos; Alberto Daniel Taibo; Jorge Ariel Jiménez; Orelvis Portal
Abstract The aim of the present study was to evaluate the artificial establishment of Beauveria bassiana and Metarhizium anisopliae as endophytes in maize plants, and its effect in controlling the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) larvae. The commercial strains B. bassiana Bb-18 and M. anisopliae Ma-30 were concentrated at 1 × 10 8 conidia ml −1 , and the soil drench method was used to establish them as endophytes in maize plant parts. The biological control assays were conducted under laboratory conditions on second and fourth larval instars of S. frugiperda . B. bassiana colonized roots, stems, and leaves of maize tissues. However, a high occurrence of B. bassiana was obtained in roots than leaves and stems with 25, 10, and 5 isolations, respectively, whereas M. anisopliae was only acquired on roots. Both entomopathogenic fungi caused (100%) mortality on the second instar larvae. In addition, B. bassiana and M. anisopliae killed (87 and 75%) of the fourth larval instars, respectively. The fungus M. anisopliae caused the highest sporulation rates during the study. These results suggest that the entomopathogenic fungi might contribute to a sustainable S. frugiperda management in maize production in Cuba.
First report of Nezara viridula transmitting Eremothecium sp. to common bean grains in Cuba
(Springer Science+Business Media, 2025) Yordanys Ramos; Orelvis Portal
Host weed plant preference of Piezodorus guildinii Westwood (Hemiptera: Pentatomidae) and its susceptibility to Beauveria bassiana in common beans management
(Springer Nature, 2024) Yordanys Ramos; Daniel Ricardo Sosa‐Gómez; Orelvis Portal
Papaya ringspot virus W infecting Luffa aegyptiaca in Cuba
(Springer Science+Business Media, 2017) Dariel Cabrera Mederos; Fabián Giolitti; Claudia Nome; Nicolás Bejerman; Orelvis Portal
Papaya ringspot virus–Carica papaya pathosystem
(Elsevier BV, 2020) Dariel Cabrera Mederos; Fabián Giolitti; Michel Leiva Mora; Orelvis Portal
Papaya—I
(Elsevier BV, 2023) Dariel Cabrera Mederos; Fabián Giolitti; Maylín Cruz; Michel Leiva Mora; Verónica Trucco; Orelvis Portal
The first report on the occurrence race 9 of the tomato leaf mold pathogen Cladosporium fulvum (syn. Passalora fulva) in Cuba
(Springer Science+Business Media, 2021) Alexander Bernal-Cabrera; Benedicto Martínez-Coca; Lidcay Herrera-Isla; Danay Ynfante Martínez; Belkis Peteira-Delgado; Orelvis Portal; Michel Leiva-Mora; P.J.G.M. de Wit