A Survey of Wild Indigenous Orchid Populations in Western Australia Reveals Spillover of Exotic Viruses.

is a terrestrial orchid endemic to southwestern Australia. The virus status of has not been studied. Eighty-three samples from 16 populations were collected, and sequencing was used to identify RNA viruses from them. In one population, all tested plants were co-infected with isolates of the exotic-to-Australia viruses Ornithogalum mosaic virus (OrMV) and bean yellow mosaic virus (BYMV). In another population, one plant was infected with BYMV. No viruses were detected in the remaining populations. The OrMV isolate shared 98-99% nucleotide identity with isolates identified from wild indigenous (Iridaceae) plants in South Africa. This suggests that the source of OrMV in may be one or more bulbous iridaceous flowering plants of southern African origin that were introduced to Western Australia as ornamentals and that have since become invasive weeds. One BYMV isolate from also exhibited 99% nucleotide identity with strains isolated from the exotic leguminous crop in Western Australia, suggesting possible spillover to indigenous species from this source. This study with highlights the probable role of invasive weeds and exotic crops as sources of exotic virus spillovers to indigenous plants.