Genetic characterization of Spermophagus niger (Coleoptera: Chrysomelidae: Bruchinae: Amblycerini) pest associated to seeds of Sorrel (Hibiscus sabdariffa L.) in Burkina Faso

2016 ◽  
Vol 6 (1) ◽  
pp. 07-14
Author(s):  
Jean Christophe Koussoubé ◽  
Fatimata Mbaye ◽  
Cheikh Abdou Khadre Mbacké Dia ◽  
Mbacké Sembène ◽  
Antoine Sanon

In Burkina Faso, the seeds of sorrel, Hibiscus sabdariffa L. are attacked by a pest identified morphologically as Spermophagus niger which is maintained all year on seeds and causing considerable damages. In the current study, for the first time, genetic characterization for S. niger was performed to determine its genetic identity and place it in its phyletic group. Mitochondrial gene, the Cytochrome oxidase I (COI) of the pest was partially sequenced after extraction and amplification by Polymerase Chain Reaction (PCR). Then the variability of genetic parameters namely the number of polymorphic and monomorphic sites, the frequencies of the different nucleotides and amino acid composition were determined. The nucleotide sequence of S. niger ob-tained was submitted in Genbank and the accession number is KU710716. Nucleotide sequences of S. niger obtained and those of different species of Spermophagus and Z. subfasciatus available in the GenBank database, we determined the percentage of similarity on the one hand and kinship through Phylogenetics reconstructions on the other hand. The results showed the absence of polymorphic sites for 406 sites obtained with 36.5% of thymine, 17.5% of cytosine, adenine 31% and 15% of guanine. Leucine was the majority amino acid (14.50%); the lysine was minority amino acid (0.76%) and cysteine was absent. The percentage of similarity obtained and phylogenetics reconstructions showed that S. niger is very close to the different species of Spermophagus particularly S. drak and different from Z. sub-fasciatus.

Plant Disease ◽  
2018 ◽  
Vol 102 (7) ◽  
pp. 1246-1253 ◽  
Author(s):  
Maher Al Rwahnih ◽  
Olufemi J. Alabi ◽  
Nathaniel M. Westrick ◽  
Deborah Golino

Increased use of metagenomics for routine virus diagnosis has led to the characterization of several genus level geminiviruses from tree fruit long thought to exclusively host RNA viruses. In this study, the identification and molecular characterization of a novel geminivirus is reported for the first time in Prunus spp. The virus, provisionally named Prunus geminivirus A (PrGVA), was identified by Illumina sequencing from an asymptomatic plum tree. PrGVA was subsequently confirmed by rolling cycle amplification, cloning, and Sanger sequencing of its complete genome (3,174 to 3,176 nucleotides) from an additional 18 (9 apricot and 9 plum) field isolates. Apart from the nonanucleotide motif TAATATT↓AC present in its virion strand origin of replication, other conserved motifs of PrGVA support its geminiviral origin. PrGVA shared highest complete genome (73 to 74%), coat protein amino acid (83 to 85%) and rep-associated amino acid (74%) identities with Grapevine red blotch virus (GRBV). PrGVA was graft but not mechanically transmissible. Quantitative polymerase chain reaction screening of Prunus spp. in the National Clonal Germplasm Repository collection using newly designed primers and probes revealed 69.4% (apricot), 55.8% (plum), and 8.3% (cherry) incidences of PrGVA. PrGVA is proposed as a novel member of the genus Grablovirus based on its close genome and phylogenetic relationship with GRBV.


Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.


2015 ◽  
Vol 45 (12) ◽  
pp. 2197-2200 ◽  
Author(s):  
Thor Vinícius Martins Fajardo ◽  
Monique Bezerra Nascimento ◽  
Marcelo Eiras ◽  
Osmar Nickel ◽  
Gilvan Pio-Ribeiro

ABSTRACT: There is no molecular characterization of Brazilian isolates of Prunus necrotic ringspot virus (PNRSV), except for those infecting peach. In this research, the causal agent of rose mosaic was determined and the movement (MP) and coat (CP) protein genes of a PNRSV isolate from rose were molecularly characterized for the first time in Brazil. The nucleotide and deduced amino acid sequences of MP and CP complete genes were aligned and compared with other isolates. Molecular analysis of the MP and CP nucleotide sequences of a Brazilian PNRSV isolate from rose and others from this same host showed highest identities of 96.7% and 98.6%, respectively, and Rose-Br isolate was classified in PV32 group.


Author(s):  
Fengnian Zhao ◽  
Yun Zhou ◽  
Yanchen Wu ◽  
Kexin Zhou ◽  
Aiqin Liu ◽  
...  

Rodents constitute the largest and most successful group of mammals worldwide. Brown rats (Rattus norvegicus) are one of the most common rodent species, and they serve as intermediate hosts of Hydatigera taeniaeformis. Although there have been a few studies reporting on the presence of the larval form of H. taeniaeformis (strobilocercus fasciolaris) in brown rats worldwide, little information is available on the genetic characterization of this parasite, with no molecular data from China. Therefore, from April 2014 to March 2016, this study was carried out to understand the prevalence and genetic characters of strobilocercus fasciolaris in brown rats captured in Heilongjiang Province in northeastern China. The livers of brown rats were collected and examined for the presence of cysts. Each cyst was identified based on morphological observation: the larvae with the naked eye and the scolexes under a microscope. The results were confirmed by polymerase chain reaction (PCR) and sequencing of the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 4 (nad4) genes. At the investigated sites, 11.8% (13/110) of the brown rats were infected with strobilocercus fasciolaris. Based on sequence analysis, there were 10 and six haplotypes regarding the cox1 and the nad4 loci, with 24 and 42 polymorphic sites, respectively (degree of intraspecific variation: 0.3%–4.4% and 0.6%–4.7%, respectively). Twelve nucleotide sequences (six of the 10 at the cox1 locus and all six at the nad4 locus) have not previously been described. Base differences in three of the six novel cox1 gene sequences and five of the six novel nad4 gene sequences caused amino acid changes. Phylogenetic analyses of the cox1 and nad4 gene sequences based on neighbor-joining and Bayesian inference trees indicated that all the strobilocercus fasciolaris isolates belonged to Hydatigera taeniaeformis sensu stricto (s.s.). This is the first report on the genetic characterization of strobilocercus fasciolaris in brown rats in China. The findings of novel cox1 and nad4 nucleotide and amino acid sequences may reflect the region-specific genetic characterization of the parasite. The data will be useful to explore the biological and epidemiological significance of the intraspecific variation within H. taeniaeformis s.s.


Plant Disease ◽  
2020 ◽  
Vol 104 (10) ◽  
pp. 2598-2605
Author(s):  
Dario Di Genova ◽  
Kippy J. Lewis ◽  
Jonathan E. Oliver

Xylella fastidiosa (Xf) is an emerging insect-vectored, xylem-limited bacterium that can cause disease on several economically important fruit and tree crops including almond, blueberry, citrus, grapevine, peach, and pecan. On blueberry, Xf causes bacterial leaf scorch (BLS), which is prevalent in the southeastern United States. This disease, previously reported to be caused by Xf subsp. multiplex (Xfm), can result in rapid plant decline and death of southern highbush (SHB) blueberry cultivars. In 2017, a survey of blueberry plantings in southern Georgia (U.S.A.) confirmed the presence of Xf-infected plants in eight of nine sites examined, and seven isolates were cultured from infected plants. Genetic characterization of these isolates through single-locus and multilocus sequence analysis revealed that three isolates from two sites belonged to Xf subsp. fastidiosa (Xff), with significant similarity to isolates from grapevine. After these three isolates were artificially inoculated onto greenhouse-grown SHB blueberries (cv. ‘Rebel’), symptoms typical of BLS developed, and Xff infection was confirmed through genetic characterization and reisolation of the bacterium to fulfill Koch’s postulates. Because all previously reported Xf isolates from blueberry have been characterized as Xfm, this is the first time that isolation of Xff has been reported from naturally infected blueberry plantings. The potential impact of Xff isolates on disease management in blueberry requires further exploration. Furthermore, given that isolates from both Xfm and Xff were obtained within a single naturally infected blueberry planting, blueberry in southern Georgia may provide opportunities for intersubspecific recombination between Xff and Xfm isolates.


2007 ◽  
Vol 13 (4) ◽  
pp. 611-613 ◽  
Author(s):  
Mariette F. Ducatez ◽  
Zekiba Tarnagda ◽  
Marc C. Tahita ◽  
Adama Sow ◽  
Sebastien de Landtsheer ◽  
...  

Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 269-275 ◽  
Author(s):  
Mohamad Chikh-Ali ◽  
Nilsa A. Bosque-Pérez ◽  
Dalton Vander Pol ◽  
Dantje Sembel ◽  
Alexander V. Karasev

The importance of potato has increased dramatically in Indonesia over the last three decades. During this period, ‘Granola’, a potato cultivar originally from Germany, has become the most common cultivar for fresh consumption in Indonesia. In August 2014, a survey was conducted in Sulawesi, where potato fields cultivated with Granola and its selection, ‘Super John’, were sampled for Potato virus Y (PVY) presence. PVY was found in Sulawesi for the first time. Samples determined to be positive for PVY were subsequently typed to strain using reverse-transcription polymerase chain reaction assays. All PVY isolates sampled were identified as PVYNTN recombinants, with three recombination junctions in P3, VPg, and CP regions of the genome. Three local PVY isolates were subjected to whole-genome sequencing and subsequent sequence analysis. The whole genomes of the Indonesian PVYNTN isolates I-6, I-16, and I-17 were found to be closely related to the European PVYNTN-A. This recombinant type was shown previously to cause potato tuber necrotic ringspot disease (PTNRD) in susceptible potato cultivars. The dependence of potato farmers on mostly a single cultivar, Granola, may have given a competitive advantage to PVYNTN over other PVY strains, resulting in the predominance of the PVYNTN recombinant. The dominance of PVYNTN in Sulawesi, and possibly in Indonesia as a whole, represents a potential risk to any newly introduced potato cultivar to the country, especially cultivars susceptible to PTNRD.


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