USDA-ARS, National Germplasm Resources Laboratory, Beltsville, MD, 20705, USA; College of Horticulture and State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Jiangsu, 210095, China.
USDA-ARS, National Germplasm Resources Laboratory, Beltsville, MD, 20705, USA; Key Laboratory of Poyang Lake Environment and Resource, School of Life Science, Nanchang University, Jiangxi, 33031, China.
Virus Res. 2019 Oct 15;272:197668. doi: 10.1016/j.virusres.2019.197668. Epub 2019 Aug 22.
Foliar chlorotic and necrotic ringspots of different sizes were observed in many ornamental camellia (Camellia spp.) species and cultivars with or without variegation symptoms. In this study, flexuous, filamentous virions of approximately 680-780 nm long were observed by electron microscopy in sap of camellia trees with chlorotic ringspots. Five large viral contigs were identified by high-throughput sequencing technology, and complete genome sequences of them were determined. Sequence analyses show that these five isolates represent three novel viruses, two in the genus Prunevirus, one in the genus Capillovirus. The genome organization of the two camellia pruneviruses resembles that of pruneviruses but does not contain the nucleic acid-binding protein (NABP) at the 3'-terminal region. They share 66.5-66.8% with each other and 51.9-58.6% with the known pruneviruses at the genome sequence level. The genome of the camellia capillovirus contains an additional NABP at the 3'-terminus when compared to those of Capillovirus. The genomes of the two capillovirus variants are 72.7% identical to each other and 42.1-48.4% to the known capilloviruses. Phylogenetic analyses support these viruses are new members of either Prunevirus or Capillovirus. The two pruneviruses are tentatively named as camellia ringspot associated virus 1 (CRSaV-1) and CRSaV-2, and the capillovirus is named as CRSaV-3. Infections of these viruses were common in camellia species, cultivars and hybrids. The viruses were also detected in seedlings from seeds collected from two camellia trees, indicating that they are seed transmissible.
在许多具有或不具有花叶症状的观赏茶花（Camellia spp.）品种和品种中，观察到大小不一的叶状褪绿和坏死环斑。在这项研究中，在具有褪绿环斑的茶花树汁液中通过电子显微镜观察到弯曲的、丝状的约 680-780nm 长的病毒粒子。通过高通量测序技术鉴定了 5 个大的病毒基因片段，并确定了它们的完整基因组序列。序列分析表明，这 5 个分离物代表了 3 种新病毒，2 种属于李痘病毒属，1 种属于细环病毒属。这两种茶花李痘病毒的基因组组织与李痘病毒相似，但在 3'末端区域不含有核酸结合蛋白（NABP）。它们在基因组序列水平上彼此之间共享 66.5-66.8%，与已知的李痘病毒共享 51.9-58.6%。与 Capillovirus 相比，茶花细环病毒的基因组在 3'末端含有额外的 NABP。两种细环病毒变体的基因组彼此之间有 72.7%的同一性，与已知的细环病毒有 42.1-48.4%的同一性。系统发育分析支持这些病毒是李痘病毒属或细环病毒属的新成员。这两种李痘病毒暂时命名为茶花环斑相关病毒 1（CRSaV-1）和 CRSaV-2，细环病毒命名为 CRSaV-3。这些病毒在茶花物种、品种和杂种中普遍感染。在从两棵茶花树上采集的种子中也检测到了这些病毒，表明它们是种子传播的。
