Guangdong nongye kexue (Oct 2022)
Molecular Identification and Genetic and Evolutionary Analysis of Sweet Potato Leaf Curl Virus Infecting Ipomoea purpurea (L.) in Hubei
Abstract
【Objective】The study is conducted to identify the viral pathogen of Ipomoea purpurea (L.) with yellow vein in Jingzhou, Hubei Province, and the results will provide theoretical basis for the effective prevention and control of this disease.【Method】One I. purpurea (L.) sample with yellow vein and curly leaves was collected from Jingzhou, Hubei Province. The sample was detected by PCR with a pair of begomovirus degenerate primers PA and PB. Gene cloning, nucleotide sequence comparison and phylogentic tree construction were applied for the comparison and genetic and evolutionary analysis of the obtained full-length genome sequence.【Result】PCR results showed that a PCR amplicon with an expect size of 363 bp were amplified from the samples, which confirmed that the collected I. purpurea (L.) were infected by begomoviruses. A full-length viral genome sequence of 2 827 bp was obtained from the positive samples by segmenting cloning. Nucleotide similarity comparison showed that the sequence in this study had more than 91% nucleotide identities with other isolates of sweet potato leaf curl virus (SPLCV) available in GenBank, and it had 97.52% and 96.81% nucleotide identities with Hunan isolate (GenBank accession number: KY783941) and Jiangsu isolate (GenBank accession number: FJ176701), respectively. According to the standards of the International Committee on Taxonomy of Viruses for the classification of begomoviruses, begomoviruses with nucleotide identities of over 91% were classified as the same virus, and the begomovirus infecting I. purpurea (L.) was identified as SPLCV. Phylogenetic tree analysis showed that the SPLCV Hubei isolate (GenBank Accession number: OM287440) were clustered in a big branch with the SPLCV isolates from China and other Asian areas, and clustered with Hunan isolate in a small branch, indicating their close evolutionary relationship.【Conclusion】SPLCV is the pathogen that infects I. purpurea (L.) in Hubei, and the disease is probably transmitted from Hunan through seedlings or Bemisia tabaci. This is the first report of SPLCV infecting I. purpurea (L.) in Hubei.
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