A preliminary survey of viruses in pasture grasses in South Africa

Abstract

Little work has been done in South Africa on the incidence of viruses in pasture grasses. The aim of this work was to carry out a survey of virus infections of some of the economically‐important pasture grasses in South Africa. Twelve winter and summer pasture grass species and one cereal forage crop species were collected from six different regions in early, mid‐ and late winter and summer. Plants were tested for virus(es) by means of symptomatology, transmission, dot‐blot immunoassays, Ouchterlony tests and electron microscopy. Serological tests indicate that Avena sativa from Roodeplaat and Bromus unioloides from Potchefstroom, Cedara and Nooitgedacht are positive for maize dwarf mosaic virus (MDMV). Lolium multiflorum from Cedara appears to be infected with two viruses, brome mosaic virus (BMV) and a potyvirus‐like agent, possibly ryegrass mosaic virus (RMV).

Min werk is in Suid‐Afrika gedoen op die voorkoms van virusse in weidingsgrasse. Die doel van hierdie studie was om ‘n opname van moontlike infeksies van ekonomiese belangrike weidingsgrasse in Suid‐Afrika te maak. Twaalf winter sowel as somer weidingsgrasspesies en een graanspesies is versamel op ses verskillende lokaliteite gedurende vroee, middel‐ en laat winter, sowel as somer. Die plante is getoets vir moontlike virusinfeksie deur middel van simptome, transmissiestudies, kol‐klad‐immunotoetse, Ouchterlony‐toetse en elektronmikroskopie. Voorlopige resul‐tate toon dat Avena sativa van Roodeplaat en Bromus unioloides van Potchefstroom, Cedara en Nooitgedacht waar‐skynlik met mieliedwergmosaiekvirus (MDMV) geïnfekteer is en dat Lolium multiflorum van Cedara waarskynlik met twee virusse geïnfekteer is, naamlik, bromemosaiekvirus (BMV) en moontlik ook rogegrasmosaiekvirus (RMV).

Additional index words:

• Brome mosaic virus
• Lolium multiflorum
• pasture grasses
• ryegrass mosaic virus
• viruses