Genus Sequivirus

Type Species	Parsnip yellow fleck virus	(PYFV)

Distinguishing Features

The RNA is about 10  kb. PYFV RNA is not polyadenylated and has no small ORF near the 3’-end. There are about 400  aa upstream of the structural proteins in the large polyprotein. Aphid transmission of PYFV depends on simultaneous or prior access to plants infected by a helper virus, Anthriscus yellows virus (genus Waikavirus).

List of Species Demarcation Criteria in the Genus

The two species are distinguished because:

	They do not cross-react with heterologous antibodies; PYFV can be divided into two serotypes (formerly regarded as separate species) that differ by serological differentiation index of 4 to 5,
	Their principal hosts belong to different families; PYFV infects umbelliferous plants (although the serotypes differ in host range) and DYMV infects plants in the Compositae,
	They are transmitted by different species of vector aphid; PYFV is transmitted by Cavariella spp. and DYMV is transmitted by Aulacorthum solani and some Myzus spp.

List of Species in the Genus

Official virus species names are in italics. Tentative virus species names, alternative names ( ), strains or serotypes are not italicized. Virus names, CMI/AAB description numbers ( ), genome sequence accession numbers [ ], and assigned abbreviations ( ) are:

Species in the Genus

Dandelion yellow mosaic virus	(DaYMV)
Parsnip yellow fleck virus (129)	(PYFV)

Tentative Species In The Genus

None reported.