An efficient and high fidelity method for amplification, cloning and sequencing of complete tospovirus genomic RNA segments

Sequence analysis of the medium and small RNAs of impatiens necrotic spot virus reveals segment reassortment but not recombination

The complete sequence of the medium (M) and small (S) RNA genome segments were determined for twelve isolates of impatiens necrotic spot virus from eight plant species. The M- and S-RNAs of these isolates shared 97-99% and 93-98% nucleotide sequence identity, respectively, with the corresponding full-length sequences available in public databases. Phylogenetic analysis based on the M- or S-RNA sequences showed incongruence in the phylogenetic position of some isolates, suggesting intraspecies segment reassortment. The lack of phylogenetic discordance in individual and concatenated sequences of individual genes encoded by M- or S-RNAs suggests that segment reassortment rather than recombination is driving evolution of these INSV isolates.

Complete Genome Segment Sequences of Tomato Chlorotic Spot Virus from Peanut in Haiti

Tomato chlorotic spot virus (TCSV) is emerging as a significant constraint to vegetable and legume crops in the Americas. The complete genome sequence of a TCSV isolate naturally infecting peanut (Arachis hypogea) in Haiti was determined in the effort to build epidemiological knowledge of the virus.

Tomato chlorotic spot virus (TCSV) is emerging as a significant constraint to vegetable and legume crops in the Americas. The complete genome sequence of a TCSV isolate naturally infecting peanut (Arachis hypogea) in Haiti was determined in the effort to build epidemiological knowledge of the virus.

Integrating Local Lesion Assays with Conventional RT-PCR for Detection of Interspecies Tospovirus Reassortants and Mixed Tospovirus Infections

Tomato spotted wilt virus (TSWV) has historically been the major tospovirus present in North America. Recent emergence of Groundnut ringspot virus (GRSV) and Tomato chlorotic spot virus (TCSV) in Florida and the Caribbean has complicated reliable identification of tospoviruses in this region. Field symptoms of these three tospoviruses are indistinguishable in most host plants, and commercially available TSWV lateral-flow immunoassay reagents cross react with GRSV and TCSV, leading to incorrect diagnoses of GRSV or TCSV as TSWV. Reliable diagnosis of TSWV, GRSV, and TCSV is further confounded by the fact that all currently known isolates of GRSV in the United States are reassortants containing one genomic RNA segment derived from TCSV. To address these practical challenges, we developed and validated genome segment-specific primers for conventional reverse-transcription polymerase chain reaction (RT-PCR) detection of the large, medium, and small RNA segments of TSWV, GRSV, and TCSV. When used in conjunction with local lesion-passaged virus isolates, the genome segment-specific RT-PCR assays developed in this study will facilitate high-throughput screening of plant or thrips samples for interspecies reassortants in epidemiological studies and reliable identification of these three tospoviruses in mixed infections commonly observed in the field.