Alternanthera mosaic virus
Alternanthera mosaic virus is a plant pathogenic virus. AltMV belongs to the virus genus Potexvirus and the virus family Alphaflexiviridae.
AltMV was first identified in 1999 in Queensland, Australia. The virus was found in Alternanthera pugens '''', a weed found in both the southern USA and Australia. Since then, AltMV has been identified in various ornamental plants in Italy, the United States, and Brazil.
This virus has a close serological relationship with another well known Potexvirus called Papaya mosaic virus. This relationship has led to several examples of misdiagnosis in the past. Sequencing has shown that the core region of the capsid protein is only 79.8% identical to PapMV at the nucleotide level. Isolates of AltMV have shown a 93-99% nucleotide identity to the original Australian isolate.
Host range and symptoms
This virus had been diagnosed in several ornamental plants since its discovery in 1999. These include moss rose, phlox, skullcap, firecracker plant, angelonia, Torenia sp, Helichrysum sp., and Salvia splendens. Three of these showed no obvious symptoms.Host range studies showed this virus can also systemically infect tomatoes, faba beans, sunflowers, and Zinnias. Some cultivars of watermelon, cucumbers, and black-eyed peas also became systemically infected. Many of these plants showed mild symptoms or were asymptomatic. The virus does not seem to infect papaya.