Geminiviridae taxonomy
A paper written by Fauquet & Stanley (2003) provides a recent update on geminivirus taxonomy and classification. Virus taxonomy has become progressively more complex, and this is particularly true for geminiviruses. Traditionally host plant names and symptoms were used to name viruses, but due to the exponentially growing number of newly described geminiviruses on the basis of their complete genomic sequences, possibilities for naming them are rapidly running out. For example, many viruses have been referred to generically as tomato yellow leaf curl and tomato leaf curl although they are known to be quite distinct entities. Therefore a new nomenclature has been proposed. Species names are written in italic (with a capital) and English vernacular names are used. To provide additional names it was agreed to add the location from where the virus was isolated. If needed, descriptors can also be added to the virus name to provide more information concerning the exact origin of a specific isolate or its particular symptom phenotype (e.g. mild or severe). Tentative species are not italicized.
So far, the Geminiviridae family includes the following genera (accepted by ICTV):
|
Genus
|
Number of species
|
Characteristics
|
Type species
|
|
Mastrevirus
|
12 species + 2 tentative species
|
Single genomic component encoding 4 proteins, infect monocotyledonous plants (with 2 exceptions), transmitted by leafhoppers
|
Maize streak virus
|
|
Curtovirus
|
3 species + 1 tentative species
|
Single genomic component encoding 7 proteins, infect dicotyledonous plants, transmitted by leafhoppers
|
Beet curly top virus
|
|
Begomovirus
|
76 species + 8 tentative species
|
Either one genomic component encoding 6 proteins, or two genomic components encoding 5-6 (DNA A) and 2 (DNA B) proteins, infect dicotyledonous plants, transmitted by whiteflies
|
Bean golden mosaic virus from Puerto Rico
|
|
Topocuvirus
|
1 species
|
Single genomic component encoding 6 proteins, infect dicotyledonous, transmitted by treehoppers
|
Tomato pseudo curly-top virus
|
The problems of species demarcation criteria, inter-species recombination, classification and phylogeny of geminiviruses are also discussed in this paper. An updated list of species and tentative species in the family Geminiviridae (agreed by the ICTV Geminiviridae Study Group) is included in this paper. The EPPO Secretariat has extracted from it, the begomoviruses causing leaf curl diseases of tomatoes. Tomato yellow leaf curl virus was added to the EPPO A2 list some years ago. As many new virus species have been described causing similar symptoms, it may be necessary at some point to decide whether the whole group of viruses causing leaf curl diseases of tomatoes should be regulated or whether only some species among this group should be selected for regulations.
|
Tomato leaf curl Bangalore virus
Tomato leaf curl Bangladesh virus
Tomato leaf curl Gujarat virus
Tomato leaf curl Karnataka virus
Tomato leaf curl Laos virus
Tomato leaf curl Malaysia virus
Tomato leaf curl New Delhi virus
Tomato leaf curl Philippines virus
Tomato leaf curl Sri Lanka virus
Tomato leaf curl Sudan virus
Tomato leaf curl Taiwan virus
Tomato leaf curl Vietnam virus
Tomato leaf curl virus
Tomato severe leaf curl virus
Tomato leaf curl India virus
Tomato leaf curl Indonesia virus
Tomato leaf curl Nicaragua virus
Tomato leaf curl Senegal virus
Tomato leaf curl Sinaloa virus
Tomato leaf curl Tanzania virus
|
Tomato yellow leaf curl China virus
Tomato yellow leaf curl Malaga virus
Tomato yellow leaf curl Sardinia virus
Tomato yellow leaf curl Thailand virus
Tomato yellow leaf curl virus
Tomato yellow leaf curl Nigeria virus
Tomato yellow leaf curl Kuwait virus
Tomato yellow leaf curl Saudi Arabia virus
Tomato yellow leaf curl Tanzania virus
Tomato yellow leaf curl Yemen virus
|
Sources
Fauquet, C.M.; Stanley, J. (2003) Geminivirus classification and nomenclature: progress and problems.
Annals of applied Biology, 142(2), 165-189.