The Experts below are selected from a list of 171 Experts worldwide ranked by ideXlab platform
Bryce W. Falk - One of the best experts on this subject based on the ideXlab platform.
-
completion of Maize Stripe Virus genome sequence and analysis of diverse isolates
Frontiers in Microbiology, 2021Co-Authors: Stephen Bolus, Bryce W. Falk, Kathryn S Braithwaite, Samuel Grinstead, Irazema Fuentesbueno, Robert Beiriger, Dimitre MollovAbstract:Maize Stripe Virus is a pathogen of corn and sorghum in subtropical and tropical regions worldwide. We used high-throughput sequencing to obtain the complete nucleotide sequence for the reference genome of Maize Stripe Virus and to sequence the genomes of ten additional isolates collected from the United States or Papua New Guinea. Genetically, Maize Stripe Virus is most closely related to rice Stripe Virus. We completed and characterized the RNA1 sequence for Maize Stripe Virus, which revealed a large open reading frame encoding a putative protein with ovarian tumor-like cysteine protease, endonuclease, and RNA-dependent RNA polymerase domains. Phylogenetic and amino acid identity analyses among geographically diverse isolates revealed evidence for reassortment in RNA3 that was correlated with the absence of RNA5. This study yielded a complete and updated genetic description of the tenuiVirus Maize Stripe Virus and provided insight into potential mechanisms underpinning its diversity.
-
In vivo transfer of barley Stripe mosaic hordeiVirus ribonucleotides to the 5′ terminus of Maize Stripe tenuiVirus RNAs
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Elizabeth M. Estabrook, James H. Tsai, Bryce W. FalkAbstract:The TenuiVirus Maize Stripe Virus (MStV) shares many properties with Viruses in the genus PhleboVirus of the family Bunyaviridae. Besides genome organization and gene expression strategies, one property shared by these plant- and vertebrate-infecting Viruses is that transcription gives rise to Virus-specific mRNAs containing nonviral 5′-terminal nucleotide sequences. The 5′-terminal nucleotides are believed to be derived from host mRNA sequences as a result of “cap-snatching.” We investigated whether specific nucleotide sequences could serve as primer donors for cap-snatching in vivo. Barley (Hordeum vulgare) plants were singly and doubly infected with MStV and the HordeiVirus barley Stripe mosaic Virus (BSMV). A reverse transcription–PCR assay was used to identify chimeric BSMV/MStV RNAs. Specific reverse transcription–PCR products were detected from doubly infected plants by using one PCR primer corresponding to the 5′ termini of the BSMV RNAs (α, β, and γ) and a second primer complementary to MStV RNA 4. The resulting cDNAs were cloned, and nucleotide sequence analysis showed them to be chimeric, containing BSMV 5′-terminal sequences as well as MStV RNA 4 sequences. All clones contained the BSMV RNA 5′ primer nucleotide sequence, but they also showed characteristics common to TenuiVirus mRNAs. More than 80% of the clones contained BSMV RNA nucleotides not present on the PCR primer. Several lacked the exact 5′ terminus of MStV RNA 4, a feature also seen for Viruses in the Bunyaviridae. These data show that heterologous Virus RNAs (BSMV) can serve as primer donors for MStV mRNA capped RNA-primed transcription in doubly infected plants.
-
in vivo transfer of barley Stripe mosaic hordeiVirus ribonucleotides to the 5 terminus of Maize Stripe tenuiVirus rnas
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Elizabeth M. Estabrook, James H. Tsai, Bryce W. FalkAbstract:The TenuiVirus Maize Stripe Virus (MStV) shares many properties with Viruses in the genus PhleboVirus of the family Bunyaviridae. Besides genome organization and gene expression strategies, one property shared by these plant- and vertebrate-infecting Viruses is that transcription gives rise to Virus-specific mRNAs containing nonviral 5′-terminal nucleotide sequences. The 5′-terminal nucleotides are believed to be derived from host mRNA sequences as a result of “cap-snatching.” We investigated whether specific nucleotide sequences could serve as primer donors for cap-snatching in vivo. Barley (Hordeum vulgare) plants were singly and doubly infected with MStV and the HordeiVirus barley Stripe mosaic Virus (BSMV). A reverse transcription–PCR assay was used to identify chimeric BSMV/MStV RNAs. Specific reverse transcription–PCR products were detected from doubly infected plants by using one PCR primer corresponding to the 5′ termini of the BSMV RNAs (α, β, and γ) and a second primer complementary to MStV RNA 4. The resulting cDNAs were cloned, and nucleotide sequence analysis showed them to be chimeric, containing BSMV 5′-terminal sequences as well as MStV RNA 4 sequences. All clones contained the BSMV RNA 5′ primer nucleotide sequence, but they also showed characteristics common to TenuiVirus mRNAs. More than 80% of the clones contained BSMV RNA nucleotides not present on the PCR primer. Several lacked the exact 5′ terminus of MStV RNA 4, a feature also seen for Viruses in the Bunyaviridae. These data show that heterologous Virus RNAs (BSMV) can serve as primer donors for MStV mRNA capped RNA-primed transcription in doubly infected plants.
-
the Maize Stripe Virus major noncapsid protein messenger rna transcripts contain heterogeneous leader sequences at their 5 termini
Virology, 1993Co-Authors: Layne Huiet, James H. Tsai, Paul A Feldstein, Bryce W. FalkAbstract:Abstract Primer extension analyses and a PCR-based cloning strategy were used to identify and characterize 5′ nucleotide sequences on the Maize Stripe Virus (MStV) RNA4 mRNA transcripts encoding the major noncapsid protein (NCP). Direct RNA sequence analysis by primer extension showed that the NCP mRNA transcripts had 10-15 nucleotides beyond the 5′ terminus of the MStV RNA4 nucleotide sequence. MStV genomic RNAs isolated from ribonucleoprotein particles (RNPs) lacked the additional 5′ nucleotides. cDNA clones representing the 5′ region of the mRNA transcripts were constructed, and the nucleotide sequences of the 5′ regions were determined for 16 clones. Each was found to have a distinct 10-15 nucleotide sequence immediately 5′ of the MStV RNA4 sequence. Eleven of 16 clones had the correct MStV RNA4 5′ nucleotide sequence, while five showed minor variations at or near the 5′ most MStV RNA4 nucleotide. These characteristics show strong similarities to other viral mRNA transcripts which are synthesized by cap snatching.
-
Complete sequence of Maize Stripe Virus RNA4 and mapping of its subgenomic RNAs
Journal of General Virology, 1992Co-Authors: Layne Huiet, James H. Tsai, Bryce W. FalkAbstract:The complete nucleotide sequence of Maize Stripe Virus RNA4 was determined and found to consist of 2227 nucleotides containing two significant open reading frames. One, in the 5' end of the viral RNA, encodes the major non-capsid protein of M(r) 19,815. The other is located in the 5' end of the viral complementary RNA and could encode a protein of M(r) 31,900. This protein has not been identified previously and has been designated NS4, a non-structural protein. RNA-RNA hybridization detected subgenomic RNAs encoding these proteins, a characteristic of RNA possessing an ambisense gene organization.
Jacques Dintinger - One of the best experts on this subject based on the ideXlab platform.
-
QTL mapping of a partial resistance to the corn delphacid-transmitted Viruses in Lepidopteran-resistant Maize line Mp705
Plant Breeding, 2013Co-Authors: Jacques Dintinger, Sylvia Salgon, Bernard ReynaudAbstract:A partial resistance to Maize mosaic Virus (MMV) and Maize Stripe Virus (MStV) was mapped in a RILs population derived from a cross between lines MP705 (resistant) and B73 (susceptible). A genetic map constructed from 131 SSR markers spanned 1399 cM with an average distance of 9.6 cM. A total of 10 QTL were detected for resistance to MMV and MStV, using composite interval mapping. A major QTL explaining 34–41% of the phenotypic variance for early resistance to MMV was detected on chromosome 1. Another major QTL explaining up to 30% of the phenotypic variation for all traits of resistance to MStV was detected in the centromeric region of chromosome 3 (3.05 bin). After adding supplementary SSR markers, this region was found to correspond well to the one where a QTL of resistance to MStV already was located in a previous mapping study using an F2 population derived from a cross between Rev81 and B73. These results suggested that these QTL of resistance to MStV detected on chromosome 3 could be allelic in Maize genome.
-
evaluation of Maize inbreds for Maize Stripe Virus and Maize mosaic Virus resistance disease progress in relation to time and the cumulative number of planthoppers
Phytopathology, 2005Co-Authors: Jacques Dintinger, Frédéric Chiroleu, Nathalie Boissot, Perla Hamon, Bernard ReynaudAbstract:Dintinger, J., Boissot, N., Chiroleu, F., Hamon, P., and Reynaud, B. 2005. Evaluation of Maize inbreds for Maize Stripe Virus and Maize mosaic Virus resistance: Disease progress in relation to time and the cumulative number of planthoppers. Phytopathology 95:600-607. Five tropical Maize lines were tested and compared with the susceptible control line B73 for resistance to Maize Stripe Virus (MStV) and Maize mosaic Virus (MMV), both propagatively transmitted by the planthopper Peregrinus maidis (Homoptera: Delphacidae). Resistance to each Virus was evaluated separately by artificial inoculations with planthoppers viruliferous for either one Virus or the other. Disease incidence and symptom severity progression were quantified in relation to time and the cumulative number of planthoppers. Line Hi40 was found to be susceptible to MStV and highly resistant to MMV. Generally, no MMV symptoms developed on Hi40, even under intense inoculation pressure by a large number of viruliferous planthoppers. Line Rev81 showed a partial but strong resistance to MStV, which mainly reduced disease incidence. Nevertheless, this resistance to MStV was the highest ever reported and held up, even when challenged by large numbers of planthoppers. The percentage of infected plants in line Rev81 never exceeded 30 to 40% in our experiments. Moderate levels of resistance to MStV, and to a lesser extent MMV, were found in lines 37-2, A211, and Mp705. However, resistance in these lines was completely overcome using a large number of insects transmitting either of the two Viruses. These results suggest that different types of resistance to MMV and MStV are available in Maize lines from Caribbean and Mascarene germ plasm. The expression of Virus-specific resistance identified in Hi40 and Rev81 lines was not affected by intense inoculation pressure. In contrast, the moderate resistance in 37-2, A211, and Mp705 was partially effective against both Viruses but not at high inoculation pressure. These different types of resistance, when present in the same genotype, could provide protection against both Viruses.
-
Evaluation of Maize inbreds for Maize Stripe Virus and Maize mosaic Virus resistance: disease progress in relation to time and the cumulative number of planthoppers
Phytopathology, 2005Co-Authors: Jacques Dintinger, Frédéric Chiroleu, Nathalie Boissot, Perla Hamon, B. ReynaudAbstract:Five tropical Maize lines were tested and compared with the susceptible control line B73 for resistance to Maize Stripe Virus (MStV) and Maize mosaic Virus (MMV), both propagatively transmitted by the planthopper Peregrinus maidis (Homoptera: Delphacidae). Resistance to each Virus was evaluated separately by artificial inoculations with planthoppers viruliferous for either one Virus or the other. Disease incidence and symptom severity progression were quantified in relation to time and the cumulative number of planthoppers. Line Hi40 was found to be susceptible to MStV and highly resistant to MMV. Generally, no MMV symptoms developed on Hi40, even under intense inoculation pressure by a large number of viruliferous planthoppers. Line Rev81 showed a partial but strong resistance to MStV, which mainly reduced disease incidence. Nevertheless, this resistance to MStV was the highest ever reported and held up, even when challenged by large numbers of planthoppers. The percentage of infected plants in line Rev81 never exceeded 30 to 40% in our experiments. Moderate levels of resistance to MStV, and to a lesser extent MMV, were found in lines 37-2, A211, and Mp705. However, resistance in these lines was completely overcome using a large number of insects transmitting either of the two Viruses. These results suggest that different types of resistance to MMV and MStV are available in Maize lines from Caribbean and Mascarene germ plasm. The expression of Virus-specific resistance identified in Hi40 and Rev81 lines was not affected by intense inoculation pressure. In contrast, the moderate resistance in 37-2, A211, and Mp705 was partially effective against both Viruses but not at high inoculation pressure. These different types of resistance, when present in the same genotype, could provide protection against both Viruses.
-
Genetic mapping of Maize Stripe disease resistance from the Mascarene source
TAG Theoretical and Applied Genetics, 2005Co-Authors: Jacques Dintinger, Frédéric Chiroleu, D. Verger, S. Caveau, Ange-marie Risterucci, J. Gilles, Brigitte Courtois, Bernard ReynaudAbstract:Maize Stripe Virus (MStV) is a potentially threatening Virus disease of Maize in the tropics. We mapped quantitative trait loci (QTLs) controlling resistance to MStV in a Maize population of 157 F2:3 families derived from the cross between two Maize lines, Rev81 (tropical resistant) and B73 (temperate susceptible). Resistance was evaluated under arti.cial inoculations in replicated screenhouse trials across di.erent seasons in Re´ union Island, France. Composite interval mapping was employed for QTL detection with a linkage map of 143 microsatellite markers. Heritability estimates across seasons were 0.96 and 0.90 for incidence and severity, respectively, demonstrating a high genotypic variability and a good control of the environment. Three regions on chromosomes 2L, 3 and 5, with major e.ects, and another region on chromosome 2S, with minor e.ects, provided resistance to MStV in Rev81. In individual seasons, the chr2L QTL explained 60–65% of the phenotypic variation for disease incidence and 21–42% for severity. The chr3 QTL, mainly associated with incidence and located near centromere, explained 42–57% of the phenotypic variation, whereas the chr5 QTL, mainly associated with severity, explained 26–53%. Overall, these QTLs explained 68–73% of the phenotypic variance for incidence and 50–59% for severity. The major QTLs on chr2 and 3 showed additive gene action and were found to be stable over time and across seasons. They also were found to be included in genomic regions with important clusters of resistance genes to diseases and pests. The major QTL on chr5 appeared to be partially dominant in favour of resistance. It was stable over time but showed highly signi.cant QTL · season interactions. Possible implications of these QTLs in di.erent mechanisms of resistance against the Virus or the insect vector are discussed. The prospects for transferring these QTLs in susceptible Maize cultivars and combining them with other resistances to Virus diseases by conventional or marker-assisted breeding are promising
-
Application of multivariate analysis to electrical penetration graphs using manual and automate waveform recognization from the planthopper Peregrinus maidis feeding on susceptible and resistant Maize
2004Co-Authors: Jacques Dintinger, Julien Lecoq, Patrick Turpin, Martial Grondin, C. Buduca, Frédéric ChiroleuAbstract:The stylet penetration activities of Peregrinus maidis (Ashmead) (Homoptera: Delphacidae), vector of Maize mosaic Virus (MMV) and Maize Stripe Virus (MStV) were studied by electrical penetration graphs (DC-EPG) on resistant and susceptible Maize inbred lines. Multivariate analyses were applied to two sets of data obtained by manual and automated methods of waveform recognition from digital EPG recordings. For both methods, the variables, which mostly explained the resistance-susceptibility status of the Maize lines, appeared to be related to the passive ingestion in phloem vessel and stylet pathway and to a lesser extent to active ingestion in xylem and to non-penetration. In spite of a great variability within each plant genotype, plants could be divided in three classes, susceptible, slightly resistant and resistant to the Virus transmission. These results are discussed in relation to the possible mechanism of Maize resistance to P. maidis and the usefulness of automated waveform recognition with the software "EPG soft" for plant breeding. (Resume d'auteur)
Bernard Reynaud - One of the best experts on this subject based on the ideXlab platform.
-
QTL mapping of a partial resistance to the corn delphacid-transmitted Viruses in Lepidopteran-resistant Maize line Mp705
Plant Breeding, 2013Co-Authors: Jacques Dintinger, Sylvia Salgon, Bernard ReynaudAbstract:A partial resistance to Maize mosaic Virus (MMV) and Maize Stripe Virus (MStV) was mapped in a RILs population derived from a cross between lines MP705 (resistant) and B73 (susceptible). A genetic map constructed from 131 SSR markers spanned 1399 cM with an average distance of 9.6 cM. A total of 10 QTL were detected for resistance to MMV and MStV, using composite interval mapping. A major QTL explaining 34–41% of the phenotypic variance for early resistance to MMV was detected on chromosome 1. Another major QTL explaining up to 30% of the phenotypic variation for all traits of resistance to MStV was detected in the centromeric region of chromosome 3 (3.05 bin). After adding supplementary SSR markers, this region was found to correspond well to the one where a QTL of resistance to MStV already was located in a previous mapping study using an F2 population derived from a cross between Rev81 and B73. These results suggested that these QTL of resistance to MStV detected on chromosome 3 could be allelic in Maize genome.
-
Effects of temperature increase on the epidemiology of three major vector-borne Viruses
European Journal of Plant Pathology, 2008Co-Authors: Bernard Reynaud, Helene Delatte, Michel Peterschmitt, Denis FargetteAbstract:The epidemiologies of Maize streak Virus (MSV), Maize Stripe Virus (MSpV), and Maize mosaic Virus (MMV) were compared in La Reunion over a three year-period. Disease incidence caused by each Virus was assessed, and the leaf and planthopper vector populations (Cicadulina mbila and Peregrinus maidis) were estimated in weekly sowings of the temperate, Virus-susceptible Maize hybrid INRA 508 and of the composite resistant cv. IRAT 297. MSV caused the most prevalent disease and MMV the least, with lower incidences in cv. IRAT 297 than in INRA 508. For each plant–Virus–vector combination, (a) disease incidence was positively correlated to vector abundance, often with 1 month of time lag; (b) annual periodicity of disease incidence and of vector numbers was consistent with highest autocorrelations and a time lag of 12 months, (c) vector numbers and disease incidence were closely associated with temperature fluctuations, both remaining relatively constant below 24°C and increasing rapidly above this threshold temperature. By contrast, relationships with rainfall and relative humidity (RH) were less consistent. Overall, 63 to 80% of the variance of disease incidence was explained through stepwise regression with vector number, temperature, and sometimes also rainfall or RH. The simple epidemiological model proposed underlines the close link between increased temperature and possible (re-) emergence of these three diseases in a Maize cropping area.
-
evaluation of Maize inbreds for Maize Stripe Virus and Maize mosaic Virus resistance disease progress in relation to time and the cumulative number of planthoppers
Phytopathology, 2005Co-Authors: Jacques Dintinger, Frédéric Chiroleu, Nathalie Boissot, Perla Hamon, Bernard ReynaudAbstract:Dintinger, J., Boissot, N., Chiroleu, F., Hamon, P., and Reynaud, B. 2005. Evaluation of Maize inbreds for Maize Stripe Virus and Maize mosaic Virus resistance: Disease progress in relation to time and the cumulative number of planthoppers. Phytopathology 95:600-607. Five tropical Maize lines were tested and compared with the susceptible control line B73 for resistance to Maize Stripe Virus (MStV) and Maize mosaic Virus (MMV), both propagatively transmitted by the planthopper Peregrinus maidis (Homoptera: Delphacidae). Resistance to each Virus was evaluated separately by artificial inoculations with planthoppers viruliferous for either one Virus or the other. Disease incidence and symptom severity progression were quantified in relation to time and the cumulative number of planthoppers. Line Hi40 was found to be susceptible to MStV and highly resistant to MMV. Generally, no MMV symptoms developed on Hi40, even under intense inoculation pressure by a large number of viruliferous planthoppers. Line Rev81 showed a partial but strong resistance to MStV, which mainly reduced disease incidence. Nevertheless, this resistance to MStV was the highest ever reported and held up, even when challenged by large numbers of planthoppers. The percentage of infected plants in line Rev81 never exceeded 30 to 40% in our experiments. Moderate levels of resistance to MStV, and to a lesser extent MMV, were found in lines 37-2, A211, and Mp705. However, resistance in these lines was completely overcome using a large number of insects transmitting either of the two Viruses. These results suggest that different types of resistance to MMV and MStV are available in Maize lines from Caribbean and Mascarene germ plasm. The expression of Virus-specific resistance identified in Hi40 and Rev81 lines was not affected by intense inoculation pressure. In contrast, the moderate resistance in 37-2, A211, and Mp705 was partially effective against both Viruses but not at high inoculation pressure. These different types of resistance, when present in the same genotype, could provide protection against both Viruses.
-
Genetic mapping of Maize Stripe disease resistance from the Mascarene source
TAG Theoretical and Applied Genetics, 2005Co-Authors: Jacques Dintinger, Frédéric Chiroleu, D. Verger, S. Caveau, Ange-marie Risterucci, J. Gilles, Brigitte Courtois, Bernard ReynaudAbstract:Maize Stripe Virus (MStV) is a potentially threatening Virus disease of Maize in the tropics. We mapped quantitative trait loci (QTLs) controlling resistance to MStV in a Maize population of 157 F2:3 families derived from the cross between two Maize lines, Rev81 (tropical resistant) and B73 (temperate susceptible). Resistance was evaluated under arti.cial inoculations in replicated screenhouse trials across di.erent seasons in Re´ union Island, France. Composite interval mapping was employed for QTL detection with a linkage map of 143 microsatellite markers. Heritability estimates across seasons were 0.96 and 0.90 for incidence and severity, respectively, demonstrating a high genotypic variability and a good control of the environment. Three regions on chromosomes 2L, 3 and 5, with major e.ects, and another region on chromosome 2S, with minor e.ects, provided resistance to MStV in Rev81. In individual seasons, the chr2L QTL explained 60–65% of the phenotypic variation for disease incidence and 21–42% for severity. The chr3 QTL, mainly associated with incidence and located near centromere, explained 42–57% of the phenotypic variation, whereas the chr5 QTL, mainly associated with severity, explained 26–53%. Overall, these QTLs explained 68–73% of the phenotypic variance for incidence and 50–59% for severity. The major QTLs on chr2 and 3 showed additive gene action and were found to be stable over time and across seasons. They also were found to be included in genomic regions with important clusters of resistance genes to diseases and pests. The major QTL on chr5 appeared to be partially dominant in favour of resistance. It was stable over time but showed highly signi.cant QTL · season interactions. Possible implications of these QTLs in di.erent mechanisms of resistance against the Virus or the insect vector are discussed. The prospects for transferring these QTLs in susceptible Maize cultivars and combining them with other resistances to Virus diseases by conventional or marker-assisted breeding are promising
-
etude du comportement alimentaire de peregrinus maidis hemiptera delphacidae sur mais par electropenetrographie et microscopie electrique a transmission
9ème Rencontres de virologie végétale 2 au 6 février 2006 Aussois, 2003Co-Authors: Daniel Gargani, Jacques Dintinger, Michel Peterschmitt, Julien Lecoq, Patrick Turpin, Martial Grondin, Jeanmichel Lett, Bernard ReynaudAbstract:L'efficacite avec laquelle un Virus est transmis aux plantes par son insecte vecteur depend de plusieurs parametres dont le comportement alimentaire de l'insecte. P. maidis est un delphacide vecteur en zone tropicale du Maize mosaic Virus (MMV, NucleorhabdoVirus) et du Maize Stripe Virus (MStV, TenuiVirus) selon le mode circulant multipliant. Pour caracteriser et differencier les etapes du comportement alimentaire de P. maidis sur mais (Zea mays), nous avons utilise un systeme d'electrophysiologie nomme electropenetrographie (EPG-DC). L'EPG nous a permis de caracteriser 5 types de signaux electriques. Dans le but de correler ces signaux a des activites biologiques de l'insecte, le trajet tissulaire et cellulaire des stylets de l'insecte a ete analyse en microscopie electronique a transmission (MET) pour trois de ces signaux. La correlation entre les signaux EPG et les observations en microscopie photonique et electronique a permis d'associer certains signaux a des activites alimentaires caracteristiques: la penetration des stylets dans le limbe foliaire, l'ingestion active dans le xyleme et l'ingestion et /ou la salivation dans le phloeme. L'identification des signaux par rapport au comportement alimentaire de P. maidis permet d'utiliser les analyses EPG pour distinguer chez le mais une resistance au Virus d'une resistance a la plante. Des hypotheses d'un mecanisme de resistance a la transmission des Virus concernes dans des mais de genotypes differents sont envisagees. (Texte integral)
Michel Peterschmitt - One of the best experts on this subject based on the ideXlab platform.
-
Effects of temperature increase on the epidemiology of three major vector-borne Viruses
European Journal of Plant Pathology, 2008Co-Authors: Bernard Reynaud, Helene Delatte, Michel Peterschmitt, Denis FargetteAbstract:The epidemiologies of Maize streak Virus (MSV), Maize Stripe Virus (MSpV), and Maize mosaic Virus (MMV) were compared in La Reunion over a three year-period. Disease incidence caused by each Virus was assessed, and the leaf and planthopper vector populations (Cicadulina mbila and Peregrinus maidis) were estimated in weekly sowings of the temperate, Virus-susceptible Maize hybrid INRA 508 and of the composite resistant cv. IRAT 297. MSV caused the most prevalent disease and MMV the least, with lower incidences in cv. IRAT 297 than in INRA 508. For each plant–Virus–vector combination, (a) disease incidence was positively correlated to vector abundance, often with 1 month of time lag; (b) annual periodicity of disease incidence and of vector numbers was consistent with highest autocorrelations and a time lag of 12 months, (c) vector numbers and disease incidence were closely associated with temperature fluctuations, both remaining relatively constant below 24°C and increasing rapidly above this threshold temperature. By contrast, relationships with rainfall and relative humidity (RH) were less consistent. Overall, 63 to 80% of the variance of disease incidence was explained through stepwise regression with vector number, temperature, and sometimes also rainfall or RH. The simple epidemiological model proposed underlines the close link between increased temperature and possible (re-) emergence of these three diseases in a Maize cropping area.
-
Evidence for a segmented genome and partial nucleotide sequences of Maize yellow Stripe Virus, a proposed new tenuiVirus
Archives of Virology, 2007Co-Authors: A. Mahmoud, Jean-claude Thouvenel, M. Royer, M. Granier, E.-d. Ammar, Michel PeterschmittAbstract:Attempts at molecular characterization of a Maize yellow Stripe Virus (MYSV) isolate from Egypt revealed that it has a tenuiVirus-like segmented genome consisting of five RNA segments (>9.5, 2.4, 2.1, 1.6 and 1.6 kb). Whereas the complete sequence of RNA-5 consists of 1562 nts, only 1152, 1085, 1213, and 808 nts of RNA-1, -2, -3, and -4, respectively, were determined from the MYSV genome, estimated to be 18 kb. Four of the MYSV segments had complementary and conserved 5′ and 3′ termini similar to those of tenuiViruses and phleboViruses. No cross hybridization was observed between MYSV and Maize Stripe Virus (MSpV), a definite member of the genus TenuiVirus . Also, no nucleotide or peptide sequence similarities were detected between the five sequenced stretches of the MYSV genome and any Virus sequences, including those of tenuiViruses, available in the databases.
-
etude du comportement alimentaire de peregrinus maidis hemiptera delphacidae sur mais par electropenetrographie et microscopie electrique a transmission
9ème Rencontres de virologie végétale 2 au 6 février 2006 Aussois, 2003Co-Authors: Daniel Gargani, Jacques Dintinger, Michel Peterschmitt, Julien Lecoq, Patrick Turpin, Martial Grondin, Jeanmichel Lett, Bernard ReynaudAbstract:L'efficacite avec laquelle un Virus est transmis aux plantes par son insecte vecteur depend de plusieurs parametres dont le comportement alimentaire de l'insecte. P. maidis est un delphacide vecteur en zone tropicale du Maize mosaic Virus (MMV, NucleorhabdoVirus) et du Maize Stripe Virus (MStV, TenuiVirus) selon le mode circulant multipliant. Pour caracteriser et differencier les etapes du comportement alimentaire de P. maidis sur mais (Zea mays), nous avons utilise un systeme d'electrophysiologie nomme electropenetrographie (EPG-DC). L'EPG nous a permis de caracteriser 5 types de signaux electriques. Dans le but de correler ces signaux a des activites biologiques de l'insecte, le trajet tissulaire et cellulaire des stylets de l'insecte a ete analyse en microscopie electronique a transmission (MET) pour trois de ces signaux. La correlation entre les signaux EPG et les observations en microscopie photonique et electronique a permis d'associer certains signaux a des activites alimentaires caracteristiques: la penetration des stylets dans le limbe foliaire, l'ingestion active dans le xyleme et l'ingestion et /ou la salivation dans le phloeme. L'identification des signaux par rapport au comportement alimentaire de P. maidis permet d'utiliser les analyses EPG pour distinguer chez le mais une resistance au Virus d'une resistance a la plante. Des hypotheses d'un mecanisme de resistance a la transmission des Virus concernes dans des mais de genotypes differents sont envisagees. (Texte integral)
-
comparative epidemiology of three Maize Viruses in reunion island in relation to the population dynamic of their vectors cicadulina mbila and peregrinus maidis
20th International Congress of Entomology Firenze Italy August 25-31 1996, 1996Co-Authors: Bernard Reynaud, Denis Fargette, Michel PeterschmittAbstract:The simultaneous presence of Maize streak Virus (MSV), Maize Stripe Virus (MStpV) and Maize mosaic Virus (MMV) in Reunion bas enabled us to study their comparative epidemiology. . Symptomatological ratings were taken through three years of culture on week1y sowings of the temperate hybrid INRA 508 and the composite variety IRAT 297. Fluctuations of emigrant populations of #C. mbila# and #P. mbila# and climatic faclors (temperature, rainfall and relative humidity) were measured and analysed by time series and stepwise regression analyses. Streak is the dominant disease, particularly during the warm rainy season and MMV was less frequent. Highest autocorrelations were observed with a time-lag of 12 months, confirming the annual periodicity of the fluctuation. Pattern of change of insect numbers was positively correlated with the change in disease incidence (correlations ranging from 0.65 to 0.87). Disease incidence and vector numbers always remained constant or increased slowly with temperature up 10 24°C and increased rapidly above 24°C. The relationship between rainfall, relative humidity, disease incidence and vector numbers is less clear. Depending on the series, from 63% to SO% of the variance of disease incidence was explained by the stepwise regression with vector numbers, and (sometimes) temperature, rainfall or relative humidity. Therefore. the close adjustement found between observed and data calculated with the resulting regression allowed us to propose a simple epidemiological model. Epidemiological data especially from Africa are compared in order to better understand the epidemiology of these Viruses. Further work is needed to confirm the validity of the mode. The rate of plants infected by the three Viruses and the number of# P. maidis# per plant were significantly lower (P = 0.0001) on IRAT 297 than on INRA 508. The resistance behavior of IRAT 297 under natural conditions points to its utilization as resistance donor in breeding program geared toward obtaining multi-resistance Maize genotypes. (Texte integral)
-
Occurrence of an isolate of Maize Stripe Virus on sorghum in India
Annals of Applied Biology, 1991Co-Authors: Michel Peterschmitt, A. S. Ratna, W.r. Sacks, D. V. R. Reddy, L. K. MughoghoAbstract:A disease characterised by chlorotic Stripes and bands, named sorghum Stripe disease (SStD), was observed on sorghum in India with an incidence of less than 0.5% to nearly 10%. The affected plants were dwarfed and had poor or no panicle formation. This disease could be transmitted by the delphacid planthopper #Peregrinus maidis# to sorghum but not to #Brachiaria eruciformis#; #Cenchrus ciliaris#; #Chloris barbata#; #Dichantium annulatum#; #Dichantium aristatum#; #Digitaria ciliaris#; #Dinebra retroflexa#; #Echinocloa colona#; #Eleusine coracana#; #Pennisetum glaucum#; #Pennisetum violaceum#; #Setaria pallida Fusca#; #Triticum aestivum# and #Zea mays#. Sorghum Stripe disease was shown to be caused by a tenuiVirus serologically related to Maize Stripe Virus (MStV). Virus particles were filamentous, less than 10 nm in width. The purified Virus preparation contained only one polypeptide of 34 500 D. Eight species of nucleic acids, four ssRNA of 1.21, 0.87, 0.73, 0.47 x 10 (6)D and four dsRNA of 2.43, 1.69, 1.40, 0.71 x 10 (6)D, were extracted from purified Virus preparations. When the four dsRNA were denatured, they migrated along with the four ssRNA species indicating that dsRNA contained duplex RNA of same molecular weight as the four ssRNA. In enzyme-linked immunosorbent assay and in electro-blot immunoassay it was evident that MStV-Sorg was serologically more closely related to the MStV isolates from Florida, Reunion and Venezuela than to a RStV isolate from Japan. The Virus was named MStV-Sorg to distinguish it from MStV which readily infects Maize. This is the first report of occurrence of a tenuiVirus in the Indian subcontinent. (Resume d'auteur)
Reynaud Bernard - One of the best experts on this subject based on the ideXlab platform.
-
Evaluation of Maize inbreds for Maize Stripe Virus and Maize mosaic Virus resistance: disease progress in relation to time and the cumulative number of planthoppers
'Scientific Societies', 2005Co-Authors: Dintinger Jacques, Boissot Nathalie, Chiroleu Frédéric, Hamon P., Reynaud BernardAbstract:International audienceFive tropical Maize lines were tested and compared with the susceptible control line B73 for resistance to Maize Stripe Virus (MStV) and Maize mosaic Virus (MMV), both propagatively transmitted by the planthopper Peregrinus maidis (Homoptera: Delphacidae). Resistance to each Virus was evaluated separately by artificial inoculations with planthoppers viruliferous for either one Virus or the other. Disease incidence and symptom severity progression were quantified in relation to time and the cumulative number of planthoppers. Line Hi40 was found to be susceptible to MStV and highly resistant to MMV. Generally, no MMV symptoms developed on Hi40, even under intense inoculation pressure by a large number of viruliferous planthoppers. Line Rev81 showed a partial but strong resistance to MStV, which mainly reduced disease incidence. Nevertheless, this resistance to MStV was the highest ever reported and held up, even when challenged by large numbers of planthoppers. The percentage of infected plants in line Rev81 never exceeded 30 to 40% in our experiments. Moderate levels of resistance to MStV, and to a lesser extent MMV, were found in lines 37-2, A211, and Mp705. However, resistance in these lines was completely overcome using a large number of insects transmitting either of the two Viruses. These results suggest that different types of resistance to MMV and MStV are available in Maize lines from Caribbean and Mascarene germ plasm. The expression of Virus-specific resistance identified in Hi40 and Rev81 lines was not affected by intense inoculation pressure. In contrast, the moderate resistance in 37-2, A211, and Mp705 was partially effective against both Viruses but not at high inoculation pressure. These different types of resistance, when present in the same genotype, could provide protection against both Viruses
-
Etude du comportement alimentaire de Peregrinus maidis (Hemiptera, Delphacidae) sur maïs, par électropénétrographie et microscopie électrique à transmission
'INIST-CNRS', 2003Co-Authors: Gargani Daniel, Turpin Patrick, Lecoq Julien, Grondin Martial, Lett Jean-michel, Dintinger Jacques, Peterschmitt Michel, Reynaud BernardAbstract:L'efficacité avec laquelle un Virus est transmis aux plantes par son insecte vecteur dépend de plusieurs paramètres dont le comportement alimentaire de l'insecte. P. maidis est un delphacide vecteur en zone tropicale du Maize mosaic Virus (MMV, NucleorhabdoVirus) et du Maize Stripe Virus (MStV, TenuiVirus) selon le mode circulant multipliant. Pour caractériser et différencier les étapes du comportement alimentaire de P. maidis sur maïs (Zea mays), nous avons utilisé un système d'électrophysiologie nommé électropénétrographie (EPG-DC). L'EPG nous a permis de caractériser 5 types de signaux électriques. Dans le but de corréler ces signaux à des activités biologiques de l'insecte, le trajet tissulaire et cellulaire des stylets de l'insecte a été analysé en microscopie électronique à transmission (MET) pour trois de ces signaux. La corrélation entre les signaux EPG et les observations en microscopie photonique et électronique a permis d'associer certains signaux à des activités alimentaires caractéristiques: la pénétration des stylets dans le limbe foliaire, l'ingestion active dans le xylème et l'ingestion et /ou la salivation dans le phloème. L'identification des signaux par rapport au comportement alimentaire de P. maidis permet d'utiliser les analyses EPG pour distinguer chez le maïs une résistance au Virus d'une résistance à la plante. Des hypothèses d'un mécanisme de résistance à la transmission des Virus concernés dans des maïs de génotypes différents sont envisagées. (Texte intégral
-
Comparative epidemiology of three Maize Viruses in Reunion Island in relation to the population dynamic of their vectors Cicadulina mbila and Peregrinus maidis
s.n., 1996Co-Authors: Reynaud Bernard, Fargette Denis, Peterschmitt MichelAbstract:The simultaneous presence of Maize streak Virus (MSV), Maize Stripe Virus (MStpV) and Maize mosaic Virus (MMV) in Réunion bas enabled us to study their comparative epidemiology. . Symptomatological ratings were taken through three years of culture on week1y sowings of the temperate hybrid INRA 508 and the composite variety IRAT 297. Fluctuations of emigrant populations of #C. mbila# and #P. mbila# and climatic faclors (temperature, rainfall and relative humidity) were measured and analysed by time series and stepwise regression analyses. Streak is the dominant disease, particularly during the warm rainy season and MMV was less frequent. Highest autocorrelations were observed with a time-lag of 12 months, confirming the annual periodicity of the fluctuation. Pattern of change of insect numbers was positively correlated with the change in disease incidence (correlations ranging from 0.65 to 0.87). Disease incidence and vector numbers always remained constant or increased slowly with temperature up 10 24°C and increased rapidly above 24°C. The relationship between rainfall, relative humidity, disease incidence and vector numbers is less clear. Depending on the series, from 63% to SO% of the variance of disease incidence was explained by the stepwise regression with vector numbers, and (sometimes) temperature, rainfall or relative humidity. Therefore. the close adjustement found between observed and data calculated with the resulting regression allowed us to propose a simple epidemiological model. Epidemiological data especially from Africa are compared in order to better understand the epidemiology of these Viruses. Further work is needed to confirm the validity of the mode. The rate of plants infected by the three Viruses and the number of# P. maidis# per plant were significantly lower (P = 0.0001) on IRAT 297 than on INRA 508. The resistance behavior of IRAT 297 under natural conditions points to its utilization as resistance donor in breeding program geared toward obtaining multi-resistance Maize genotypes. (Texte intégral
-
Maize streak Virus, Maize Stripe Virus and Maize mosaic Virus in the tropics (Africa and islands in the Indian Ocean)
1995Co-Authors: Marchand Jean-leu, Reynaud Bernard, Peterschmitt Michel, Dintinger JacquesAbstract:Ces trois viroses, connues depuis le début du siècle et répandues dans toutes les régions tropicales ont été plus précisément étudiées en Afrique et à la Réunion. La striure est causée par le Maize streak Virus (MSV), le Stripe est provoqué par le Maize Stripe Virus (MStpV) et la mosaïque par le Maize mosaic Virus (MMV). Ces Virus sont obligatoirement transmis par des insectes. Ces insectes ont été identifiés sur le continent africain. Les épidémies de striure peuvent provoquer des dégâts importants; l'impact des viroses causées par le MStpV et le MMV est encore mal connu. Les symptômes des trois Virus sont décrits, et l'épidémiologie est étudiée au Burkina et à la Réunion. Les Virus sont identifés à l'aide des tests immunoenzymatique s ELISA. Les sélections variétales ont eu pour objectif de transférer des résistances dans des variétés d'un bon intérêt agronomique, à la Réunion et au Togo. A partir de variétés locales, un "Composite viroses résistant" a été constitué, puis amélioré. Des transferts sont réalisés sur des variétés africaines ou introduites à la Réunion et au Togo. (Résumé d'auteur
-
Les viroses de la striure, du Stripe et de la mosaïque sur le maïs en région tropicale (Afrique et îles de l'océan Indien)
1994Co-Authors: Marchand Jean-leu, Peterschmitt Michel, Reynaud BernardAbstract:Ces trois viroses, connues depuis le début du siècle et répandues dans toutes les régions tropicales ont été plus précisément étudiées en Afrique et à la Réunion. La striure est causée par le Maize streak Virus (MSV), le Stripe est provoqué par le Maize Stripe Virus (MStpV) et la mosaïque par le Maize mosaic Virus (MMV). Ces Virus sont obligatoirement transmis par des insectes. Ces insectes ont été identifiés sur le continent africain. Les épidémies de striure peuvent provoquer des dégâts importants; l'impact des viroses causées par le MStpV et le MMV est encore mal connu. Les symptômes des trois Virus sont décrits, et l'épidémiologie est étudiée au Burkina et à la Réunion. Les Virus sont identifés à l'aide des tests immunoenzymatique s ELISA. Les sélections variétales ont eu pour objectif de transférer des résistances dans des variétés d'un bon intérêt agronomique, à la Réunion et au Togo. A partir de variétés locales, un "Composite viroses résistant" a été constitué, puis amélioré. Des transferts sont réalisés sur des variétés africaines ou introduites à la Réunion et au Tog
