Corchorus yellow vein Vietnam virus (CoYVV) is a geminivirus that affects yield and quality in jute. Its genome is consisted of two circular single-stranded DNAs, named DNA-A and DNA-B, respectively. Detection of CoYVV and screening of resistant germplasm will not only increase our understanding of geminivirus distribution and evolution but also lay the foundation for resistance gene cloning. Funong 5 (C. olitorius.) was suspected to be infected with leaf mosaic symptoms in jute germplasm resource nursery of Yangzhong Science and Education Base of Fujian Agriculture and Forestry University (Sanming, Fujian, China) in 2018. The diseased samples were collected and subjected to total DNA extraction by CTAB. The virus in the sample was identified by PCR, RCA, and sequencing. Then the mixture of Agrobacterium tumefaciens containing two plasmids (infectious clone vector plasmids of CoYVV DNA-A and DNA-B) in 1:1 ratio was injected to 7 representative C. capsularis varieties and 7 representative C. olitorius ones. After inoculation, we investigated symptom development (disease incidence) and PCR was used to detect the rate of infection. The results showed that the symptomatic samples in the field were infected by an isolate of CoYVV (CoYVV-FS). The size of the DNA-A and DNA-B of CoYVV-FS were 2724 bp and 2691 bp, respectively. Phylogenetic analysis revealed that CoYVV-FS was more related to New World begomoviruses than to Old World begomoviruses. Moreover, the inoculation of 14 representative jute varieties showed that CoYVV was infectious to jute. The disease incidence was 0 in the 7 C. capsularis varieties and 0-60% in the 7 C. olitorius varieties. The infection rates for the 14 jute varieties was from 0 to 100%. Both disease incidence and infection rates of 807 yuanyinmali (C. olitorius) were 0, indicating that it was the resistant germplasm; while Bachang4 (C. olitorius) and Yindumolvzi (C. olitorius) produced yellow vein and curly-leaf phenotypes after 30 days of inoculation, showing that it was the sensitive germplasm. The CoYVV-FS in jute germplasm resource nursery belonged to the same isolate as the CoYVV previously reported, which could infect most jute varieties (lines) and cause serious symptoms in C. olitorius.
