A New Isolate of Iris Severe Mosaic Virus Causing Yellow Mosaic in Iris ensata Thunb

摘要

Severe mosaic disease was observed on Iris ensata Thunb. in Spring 2008, in Hangzhou, China and it was found to be widely distributed in that region. Detection of viruses by electron microscopy resulted in the occurrence of a potyvirus in most symptomatic seedlings. Sequencing 1745 nucleotides of the 3'-terminal region of the genome of the typical viral isolate revealed that it was a new isolate of Iris severe mosaic potyvirus (ISMV), tentatively named ISMV-PHz. This strain shared high nucleotide identity with ISMV. Phylogenetic analysis also showed that this isolate clustered with iris severe mosaic potyvirus (ISMV) and onion yellow dwarf virus (OYDV) into a monophyletic group, and was closest in similarity to ISMV. The divergence of potyvirus-infecting iris species had a higher degree of relevance with natural host but not with the region from which it was isolated. This is the first report of ISMV isolated from I. ensata in China.