MUSA VIRUSES IN NIGERIA
J d'A HUGHES1 and G DAHAL2
1IITA, lbadan, Nigeria; 2University of Minnesota, St Paul, MN, USA
Background and objectives
Materials and methods
Results and conclusions
While the symptoms of CMV are usually distinct, they can be confused with those exhibited by plants infected with BSV. The presence of CMV was confirmed in both banana and plantain, but was less common than BSV. CMV was also found in mixed infection with BSV in plantain. CMV in banana and plantain was found to be distinct from that found to be infecting adjacent cowpeas, causing less severe symptom expression after mechanical inoculation and vector transmission to N. tabacum.
The presence of BDBV was confirmed in banana by ELISA but was not found to be widely distributed. It was found in mixed infection with BSV in some cases. The vector of the virus is unknown but it is putatively a member of the nepovirus group, exhibiting a serological relationship with tobacco ringspot, tomato ringspot and cacao necrosis nepoviruses.
The presence of these viruses in banana and plantain, and the failure to eliminate BSV by meristem culture, emphasises the need for care in selecting planting material as these viruses can all be transmitted vegetatively through suckers used as planting material. With regard to their spread, no natural vector has been identified for BSV although mealybugs are implicated; aphids are known to be vectors of CMV and no vector has been found for BDBV.
The epidemiology of these viruses in Nigeria is not known. Despite the presence of large numbers of mealybugs, there appears to be no natural spread of BSV. Spread of CMV through vector transmission appears to be very localised, as does the occurrence of BDBV. However, care must be taken as these three viruses are transmitted vegetatively through suckers and can often be widely distributed by farmers and national/international germplasm movement.