Widespread incidence of Gloriosa stripe mosaic virus infecting Gloriosa superba in São Paulo state, Brazil

Abstract

In 2016, a virus causing foliar mosaic and color break in flowers was isolated from Gloriosa superba plants (gloriosa lily) purchased at four different flower markets in the city of São Paulo (São Paulo state, Brazil). Gloriosa lily leaf and flower extracts were inoculated on indicator plants from the families Amaranthaceae, Cucurbitaceae, and Solanaceae, and processed for observations under transmission electron microscope. Following serological tests (ELISA) with potyvirus group and cucumber mosaic virus antisera, the extracts were also submitted to RT-PCR, sequencing, and sequence analyses. The virus was not mechanically transmitted and ELISA results were negative. However, several flexuous particles were observed in negatively stained leaf extract, as well as pinwheel and lamellar inclusions typical of potyvirus infections in ultrathin sections of infected parenchymal leaf tissue. Analysis of the sequences corresponding to the coat protein region obtained after RT-PCR and sequencing indicated nucleotide identity ranging from 84 to 99% with Gloriosa stripe mosaic virus (GSMV, genus Potyvirus). A survey of GSMV occurrence in gloriosa lily producing regions in São Paulo state revealed 100% infection in all of the crops assessed.