SUMMARYSunflower chlorotic mottle virus (SuCMoV) was detected in several sunflower (Helianthus an... more SUMMARYSunflower chlorotic mottle virus (SuCMoV) was detected in several sunflower (Helianthus annuus L.) growing areas, causing a disease characterized by systemic chlorotic mottling. Symptom severity depended on several factors, including the ontogenetic stage at which infections occur. The objective of this study was to determine the effects of artificial infections with SuCMoV at different ontogenetic stages on agronomic yield characters (plant height, stem and capitulum diameters, achene yield, seed width and length, weight of 1000 seeds and oil content). Sunflower seeds of commercial hybrids Dekalb 4030, Contiflor 3N, and ACA 884 were sown in a split plot design with four replications, which were mechanically inoculated with SuCMoV at four growth stages. A negative (non-inoculated) control was included in the experiment. Virus infection was detected by symptoms and by double antibody sandwich enzymelinked immunosorbent assay (DAS-ELISA). Virus infections at all stages signific...
41° Congreso Argentino de Horticultura. V Simposio de Aromáticas, Medicinales y Condimenticias. La Plata - Virtual. 5 al 8 de octubre de 2021, Oct 5, 2021
5° Congreso Argentino de Fitopatología. 59° Reunión de la División Caribe de la APS / Asociación Argentina de Fitopatólogos; American Phytopathological Society – Caribbean Division, 22 y 23 de septiembre de 2021, modalidad virtual, Sep 22, 2021
Sunflower chlorotic mottle virus (SuCMoV), the most prevalent virus of sunflower in Argentina, wa... more Sunflower chlorotic mottle virus (SuCMoV), the most prevalent virus of sunflower in Argentina, was reported naturally infecting not only sunflower but also weeds. To understand SuCMoV evolution and improve the knowledge on its variability, the complete genomic sequences of two SuCMoV isolates collected from Dipsacus fullonum (-dip) and Ibicella lutea (-ibi) were determined from three overlapping cDNA clones and subjected to phylogenetic and recombination analyses. SuCMoV-dip and -ibi genomes were 9,953-nucleotides (nt) long; their sequences contained an open reading frame of 9,561 nucleotides, which encoded a polyprotein of 3,187 amino acids flanked by a 5'-noncoding region (NCR) of 135 nt and a 3'-NCR of 257 nt. SuCMoV-dip and -ibi genome nucleotide sequences were 90.9 identical and displayed 90 and 94.6 % identity to that of SuCMoV-C, and 90.8 and 91.4 % identity to that of SuCMoV-CRS, respectively. P1 of SuCMoV-dip and -ibi was 3-nt longer than that of SuCMoV-CRS, but 12-nt shorter than that of SuCMoV-C. Two recombination events were detected in SuCMoV genome and the analysis of d(N)/d(S) ratio among SuCMoV complete sequences showed that the genomic regions are under different evolutionary constraints, suggesting that SuCMoV evolution would be conservative. Our findings provide evidence that mutation and recombination would have played important roles in the evolutionary history of SuCMoV.
An emerging virus isolated from papaya (Carica papaya) crops in northwestern (NW) Argentina was s... more 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 th...
Alfalfa (Medicago sativa L.) growing areas of Argentina were surveyed between 2010 and 2018 to de... more Alfalfa (Medicago sativa L.) growing areas of Argentina were surveyed between 2010 and 2018 to determine the geographical distribution and analyse the genetic diversity among alfalfa enamovirus-1 (AEV-1) isolates. The virus was detected in all 17 surveyed alfalfa-producing provinces, with a prevalence of 64%. The plant virus AEV-1 is widely distributed in the country, and its transmission vector has been unknown until now. Here we show that the black aphid Aphis craccivora can transmit AEV-1. The CP sequence identity among 16 AEV-1 isolates from Argentina was from 98 to 100% and from 98.9 to 100% at nucleotide and amino acid levels, respectively, indicating a low level of sequence variation among these isolates. The phylogenetic analysis based on the complete nucleotide sequence of the CP gene indicated that AEV-1 isolates are closely related and clustered in a monophyletic group. These results suggest that AEV-1 has spread very recently in Argentina. In the present study, we report the geographical distribution of AEV-1 in the main alfalfa-growing areas of Argentina and, for the first time, identify an insect vector and describe the CP gene diversity of an enamovirus worldwide.
Dipsacus fullonum L. is a biennial weed that is widely spread in the Pampean region of Argentina.... more Dipsacus fullonum L. is a biennial weed that is widely spread in the Pampean region of Argentina. Plants of this species showing leaf mosaic symptoms were collected near sunflower (Helianthus annuus L.) crops infected with Sunflower chlorotic mottle virus (SuCMoV). ...
A bromovirus isolated from sunflower (Helianthus annuus L.) was characterised and shown to be h... more A bromovirus isolated from sunflower (Helianthus annuus L.) was characterised and shown to be highly related to Pelargonium zonate spot virus (PZSV), a virus reported in Italy, Spain, France, USA and Israel. Sunflower plants showing chlorotic concentric ring and linear pattern symptoms were observed near Paraná city (Entre Ríos Province) in commercial sunflower crops. This was the first observation of this type of symptoms in sunflower in Argentina, but similar ones have been reported in Africa and Mexico. The aim of this study was to characterize this new sunflower disease. The characterization was based on virus transmission, host range, electron microscopy and comparison of its sequence with those of related viruses. Virus transmission efficiency by mechanical inoculation to sunflower plants at the V2 vegetative stage was nearly 100%. Seed transmission was negative as plants derived from seeds of systemically infected plants showed no symptoms. A host range including 27 spe...
In 2014-2015, raspberry (Rubus idaeus) cv. Autum bliss plants with dwarfism and foliar chlorosis ... more In 2014-2015, raspberry (Rubus idaeus) cv. Autum bliss plants with dwarfism and foliar chlorosis were observed in commercial fields in parallel 42° in the Patagonia region of Argentina. Symptoms were similar to those observed in raspberry infected by Raspberry bushy dwarf virus (RBDV) in the USA (Ellis et al., 2005; Martin et al., 2013). A survey was conducted to determine if RBDV was also present in Argentinian raspberry fields. Transmission electron microscope observations of leaf dip preparations revealed the presence of spherical particles of 30 nm, resembling those of virus members of the genus Ideaovirus. RBDV was detected in 88 of the 130 plants (68%) tested using double-antibody sandwich ELISA with a specific polyclonal antiserum (Bioreba AG, Switzerland). RNA was extracted with SpectrumTM Plant Total RNA Kit (Sigma-Aldrich, USA) and tested by RT-PCR using a pair of specific primers to the capsid protein gene (Wang et al., 2008). Expected fragments of 825 bp were obtained an...
Two potyviruses that infect sunflower (Helianthus annuus L.) crops have been reported in Argent... more Two potyviruses that infect sunflower (Helianthus annuus L.) crops have been reported in Argentina. Sunflower chlorotic mottle virus (SuCMoV) is the most widely distributed one, with two strains: common and ring spot, which have been completely characterized. Sunflower mild mosaic virus (SuMMoV) that produces a chlorotic mild mosaic on sunflower commercial crops was detected in the rural area of Paraná (Entre Ríos Province). This virus has been biologically and serologically characterized but not fully characterized at the molecular level. The aim of this work was to determine the complete sequence of SuMMoV and study its genomic organization. A total RNA extraction was made from a preparation enriched with this virus. The quality of preparation was confirmed through electron microscopy and RT-PCR with specific primers for capsid protein gene. Total RNA obtained was pyrosequenced and the sequences obtained were analyzed. Electron microscopy from rapid preparations of samples e...
SUMMARYSunflower chlorotic mottle virus (SuCMoV) was detected in several sunflower (Helianthus an... more SUMMARYSunflower chlorotic mottle virus (SuCMoV) was detected in several sunflower (Helianthus annuus L.) growing areas, causing a disease characterized by systemic chlorotic mottling. Symptom severity depended on several factors, including the ontogenetic stage at which infections occur. The objective of this study was to determine the effects of artificial infections with SuCMoV at different ontogenetic stages on agronomic yield characters (plant height, stem and capitulum diameters, achene yield, seed width and length, weight of 1000 seeds and oil content). Sunflower seeds of commercial hybrids Dekalb 4030, Contiflor 3N, and ACA 884 were sown in a split plot design with four replications, which were mechanically inoculated with SuCMoV at four growth stages. A negative (non-inoculated) control was included in the experiment. Virus infection was detected by symptoms and by double antibody sandwich enzymelinked immunosorbent assay (DAS-ELISA). Virus infections at all stages signific...
41° Congreso Argentino de Horticultura. V Simposio de Aromáticas, Medicinales y Condimenticias. La Plata - Virtual. 5 al 8 de octubre de 2021, Oct 5, 2021
5° Congreso Argentino de Fitopatología. 59° Reunión de la División Caribe de la APS / Asociación Argentina de Fitopatólogos; American Phytopathological Society – Caribbean Division, 22 y 23 de septiembre de 2021, modalidad virtual, Sep 22, 2021
Sunflower chlorotic mottle virus (SuCMoV), the most prevalent virus of sunflower in Argentina, wa... more Sunflower chlorotic mottle virus (SuCMoV), the most prevalent virus of sunflower in Argentina, was reported naturally infecting not only sunflower but also weeds. To understand SuCMoV evolution and improve the knowledge on its variability, the complete genomic sequences of two SuCMoV isolates collected from Dipsacus fullonum (-dip) and Ibicella lutea (-ibi) were determined from three overlapping cDNA clones and subjected to phylogenetic and recombination analyses. SuCMoV-dip and -ibi genomes were 9,953-nucleotides (nt) long; their sequences contained an open reading frame of 9,561 nucleotides, which encoded a polyprotein of 3,187 amino acids flanked by a 5'-noncoding region (NCR) of 135 nt and a 3'-NCR of 257 nt. SuCMoV-dip and -ibi genome nucleotide sequences were 90.9 identical and displayed 90 and 94.6 % identity to that of SuCMoV-C, and 90.8 and 91.4 % identity to that of SuCMoV-CRS, respectively. P1 of SuCMoV-dip and -ibi was 3-nt longer than that of SuCMoV-CRS, but 12-nt shorter than that of SuCMoV-C. Two recombination events were detected in SuCMoV genome and the analysis of d(N)/d(S) ratio among SuCMoV complete sequences showed that the genomic regions are under different evolutionary constraints, suggesting that SuCMoV evolution would be conservative. Our findings provide evidence that mutation and recombination would have played important roles in the evolutionary history of SuCMoV.
An emerging virus isolated from papaya (Carica papaya) crops in northwestern (NW) Argentina was s... more 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 th...
Alfalfa (Medicago sativa L.) growing areas of Argentina were surveyed between 2010 and 2018 to de... more Alfalfa (Medicago sativa L.) growing areas of Argentina were surveyed between 2010 and 2018 to determine the geographical distribution and analyse the genetic diversity among alfalfa enamovirus-1 (AEV-1) isolates. The virus was detected in all 17 surveyed alfalfa-producing provinces, with a prevalence of 64%. The plant virus AEV-1 is widely distributed in the country, and its transmission vector has been unknown until now. Here we show that the black aphid Aphis craccivora can transmit AEV-1. The CP sequence identity among 16 AEV-1 isolates from Argentina was from 98 to 100% and from 98.9 to 100% at nucleotide and amino acid levels, respectively, indicating a low level of sequence variation among these isolates. The phylogenetic analysis based on the complete nucleotide sequence of the CP gene indicated that AEV-1 isolates are closely related and clustered in a monophyletic group. These results suggest that AEV-1 has spread very recently in Argentina. In the present study, we report the geographical distribution of AEV-1 in the main alfalfa-growing areas of Argentina and, for the first time, identify an insect vector and describe the CP gene diversity of an enamovirus worldwide.
Dipsacus fullonum L. is a biennial weed that is widely spread in the Pampean region of Argentina.... more Dipsacus fullonum L. is a biennial weed that is widely spread in the Pampean region of Argentina. Plants of this species showing leaf mosaic symptoms were collected near sunflower (Helianthus annuus L.) crops infected with Sunflower chlorotic mottle virus (SuCMoV). ...
A bromovirus isolated from sunflower (Helianthus annuus L.) was characterised and shown to be h... more A bromovirus isolated from sunflower (Helianthus annuus L.) was characterised and shown to be highly related to Pelargonium zonate spot virus (PZSV), a virus reported in Italy, Spain, France, USA and Israel. Sunflower plants showing chlorotic concentric ring and linear pattern symptoms were observed near Paraná city (Entre Ríos Province) in commercial sunflower crops. This was the first observation of this type of symptoms in sunflower in Argentina, but similar ones have been reported in Africa and Mexico. The aim of this study was to characterize this new sunflower disease. The characterization was based on virus transmission, host range, electron microscopy and comparison of its sequence with those of related viruses. Virus transmission efficiency by mechanical inoculation to sunflower plants at the V2 vegetative stage was nearly 100%. Seed transmission was negative as plants derived from seeds of systemically infected plants showed no symptoms. A host range including 27 spe...
In 2014-2015, raspberry (Rubus idaeus) cv. Autum bliss plants with dwarfism and foliar chlorosis ... more In 2014-2015, raspberry (Rubus idaeus) cv. Autum bliss plants with dwarfism and foliar chlorosis were observed in commercial fields in parallel 42° in the Patagonia region of Argentina. Symptoms were similar to those observed in raspberry infected by Raspberry bushy dwarf virus (RBDV) in the USA (Ellis et al., 2005; Martin et al., 2013). A survey was conducted to determine if RBDV was also present in Argentinian raspberry fields. Transmission electron microscope observations of leaf dip preparations revealed the presence of spherical particles of 30 nm, resembling those of virus members of the genus Ideaovirus. RBDV was detected in 88 of the 130 plants (68%) tested using double-antibody sandwich ELISA with a specific polyclonal antiserum (Bioreba AG, Switzerland). RNA was extracted with SpectrumTM Plant Total RNA Kit (Sigma-Aldrich, USA) and tested by RT-PCR using a pair of specific primers to the capsid protein gene (Wang et al., 2008). Expected fragments of 825 bp were obtained an...
Two potyviruses that infect sunflower (Helianthus annuus L.) crops have been reported in Argent... more Two potyviruses that infect sunflower (Helianthus annuus L.) crops have been reported in Argentina. Sunflower chlorotic mottle virus (SuCMoV) is the most widely distributed one, with two strains: common and ring spot, which have been completely characterized. Sunflower mild mosaic virus (SuMMoV) that produces a chlorotic mild mosaic on sunflower commercial crops was detected in the rural area of Paraná (Entre Ríos Province). This virus has been biologically and serologically characterized but not fully characterized at the molecular level. The aim of this work was to determine the complete sequence of SuMMoV and study its genomic organization. A total RNA extraction was made from a preparation enriched with this virus. The quality of preparation was confirmed through electron microscopy and RT-PCR with specific primers for capsid protein gene. Total RNA obtained was pyrosequenced and the sequences obtained were analyzed. Electron microscopy from rapid preparations of samples e...
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