Garlic (
Allium sativum L.) is a host to several
viruses, most commonly those
belonging to theAllexivirus,
Carlavirus, orPotyvirusgenera. Nine species distributed among these three genera have been reported in
Brazil two species within
carlaviruses, two within
potyviruses, and five within
allexiviruses. To quantify the
prevalence of these
viruses, young leaves from 520
plants (
plants either symptomatic or asymptomatic) were collected from commercial fields grown in four Brazilian states and analyzed using universal and species-specific primers via the
reverse transcription polymerase chain reaction (RT-PCR).
Potyvirus presence was positive in 306 samples (81 %), 151 of them (38 %) in
mixed infections with other
viruses. The most frequent
potyviruses wereOnion yellow dwarf
virus(OYDV, 56 %) andLeek yellow stripe
virus(LYSV, 55 %). 187 samples (49 %) were positive for
allexivirus, with 33 (9 %) showing single
infections and 154 (41 %) showing
mixed infections withGarlic
virus A (GarV-A),
Garlic virus B(GarV-B),
Garlic virus C(GarV-C),
Garlic virus D(GarV-D), and species
belonging to theCarlavirus andPotyvirusgenera. The predominant species in which
allexiviruses were found were GarV-A and GarV-D. Only 15 samples (4 %) were infected solely by a
carlavirus, and 63 (17 %) showed
mixed infections with
viruses from different genera. The dominant species of
carlavirus wasGarlic commom latent
virus(GarCLV).
Carlaviruses and
allexiviruses are frequently associated with
mixed infections with
potyviruses, whereas
mixed infections with
carlaviruses and
allexiviruses are rare. About 70 % of the
plants collected were positive for at least one species of
virus.