Molecular Identification Of Geminiviruses Infecting Ageratum Conyzoides And Stachytarpheta Jamaicensis

Geminiviruses infecting Ageratum conyzoides and Stachytarpheta jamaicensis were identified with molecular data in this paper.5 virus samples collected from Ageratum conyzoides and Stachytarpheta jamaicensis in Hainan were detected with triple antibody sandwich ELISA (TAS-ELISA) and PCR, results showed all the virus samples were infected by whitefly-transmitted geminiviruses. Sequence analyses showed two types of viruses existed among those samples, and sample Hn2 was mix-infected by two types of viruses. On the basis of these data, complete genomic structure of the two types of viruses was studied.Two full-length DNA-A molecules (Hn2-1; Hn2-19) from Ageratum conyzoides sample Hn2 were cloned and sequenced. Sequence analyses and comparisons showed DNA-A of Hn2-l and Hn2-19 was most closely related with Ageratum yellow vein virus (AYVV, X74516) (85% sequence identity). In general, overall nucleotide sequence identity between two distinct geminiviruses is less than 90%. According to this criterion, these virus isolates were named as Ageratum yellow vein China virus (AYVCNV). Hn2-l and Hn2-19 were different molecules cloned from sample Hn2 and shared 97.7% nucleotide sequence identity, so they were different isolates of AYVCNV mix-infecting sample Hn2.Three full-length DNA-A molecules (Hn5-1, Hn5-4 and Hn6-1) from Stachytarpheta jamaicensis sample Hn5 and Hn6 were cloned and sequenced. Sequence analyses and comparison showed all the 3 full-length nucleotide sequences were most closely related with Tomato leaf curl virus from Indonesia (ToLCV, AB100305). According to geminivirus taxonomic criteria, we named these viruse isolates as Stachytarpheta leaf curl virus (StaLCV). Hn5-1, Hn5-4 and Hn6-l shared more than 95% identity to each other, indicating they are different isolates of StaLCV. Hn5-1 and Hn5-4 were cloned from same sample Hn5, indicating Hn5 were mix-infected by StaLCV isolates.