Molecular characterization of Cucumber mosaic virus infecting Gladiolus, revealing its phylogeny distinct from the Indian isolate and alike the Fny strain of CMV

Abstract

The majority of Gladiolus plants growing in the botanical garden at NBRI, Lucknow, India and adjoining areas exhibited symptoms of mosaic, color breaking, stunting of spikes and reduction in flower size. The occurrence of Cucumber mosaic virus (CMV) was suspected in symptomatic Gladiolus plants. Cucumber mosaic virus, the type species of the genus Cucumovirus of the family Bromoviridae, is an important plant virus worldwide, which infects many plants and causes quantity and quality losses. For virus characterization, total RNA was isolated from leaves of infected plants and used in reverse transcriptase polymerase chain reaction with a primer set designed in the Cucumber mosaic virus coat protein region. Viral amplicons of the expected 657 bp size were obtained from infected plants. No viral amplicon was obtained from healthy control plants. Viral amplicons were cloned and sequenced (DQ295914). Molecular characterization was performed and phylogenetic relationship determined by the comparison of coat protein gene nucleotide and amino acid sequences with other Cucumber mosaic virus isolates reported from India and worldwide. The nucleotide and amino acid percentage comparison and phylogenetic tree results revealed that Cucumber mosaic virus infecting Gladiolus show resemblance with the Fny strain, which is not common in the Asian continent.