title: Distribution and molecular diversity of three cucurbit-infecting poleroviruses in China.
abstract: Cucurbit aphid-borne yellows virus (CABYV) and Melon aphid-borne yellows virus (MABYV) have been found to be associated with cucurbit yellowing disease in China. Our report identifies for the first time a third distinct polerovirus, tentatively named Suakwa aphid-borne yellows virus (SABYV), infecting Suakwa vegetable sponge. To better understand the distribution and molecular diversity of these three poleroviruses infecting cucurbits, a total of 214 cucurbitaceous crop samples were collected from 25 provinces in China, and were investigated by RT-PCR and sequencing. Of these, 108 samples tested positive for CABYV, while 40 samples from five provinces were positive for MABYV, and SABYV was detected in only 4 samples which were collected in the southern part of China. Forty-one PCR-amplified fragments containing a portion of the RdRp gene, intergenic NCR and CP gene were cloned and sequenced. Sequence comparisons showed that CABYV isolates shared 78.0-79.2% nucleotide sequence identity with MABYV isolates, and 69.7-70.8% with SABYV. Sequence identity between MABYV and SABYV was 73.3-76.5%. In contrast, the nucleotide identities within each species were 93.2-98.7% (CABYV), 98.1-99.9% (MABYV), and 96.1-98.6% (SABYV). Phylogenetic analyses revealed that the polerovirus isolates fit into three distinct groups, corresponding to the three species. The CABYV group could be further divided into two subgroups: the Asia subgroup and the Mediterranean subgroup, based on CP gene and partial RdRp gene sequences. Recombination analysis suggested that MABYV may be a recombinant virus.
authors: Department of Plant Pathology, State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100193, China.
authors: Qiao-xia
authors: QX
authors: Shang
authors: Hai-ying
authors: HY
authors: Xiang
authors: Cheng-gui
authors: CG
authors: Han
authors: Da-wei
authors: DW
authors: Li
authors: Jia-lin
authors: JL
authors: Yu
mesh_terms: D002681:China; D003001:Cloning, Molecular; D016000:Cluster Analysis; D029776:Luffa / Q000821:virology*; D052679:Luteoviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins