Xiphinema spp., putative vectors for Brome mosaic virus (BMV), are not associated with BMV-infected wheat plants in Alabama

Brome mosaic virus (BMV) was first detected in Alabama on wheat in 2002. Since that time it has been detected in wheat plants in all counties where wheat is grown, indicating it has become established in all wheat growing regions of the state. Wheat is an important winter crop in Alabama and is grown for both seed and animal feed. A vector for BMV has been reported to be the dagger nematode, Xiphinema spp. This study was conducted to determine if this nematode was associated with wheat production and the occurrence of the virus in Alabama. Soil samples were collected from a wheat variety trial and grower wheat fields throughout the state monthly during the growing season. Nematodes were extracted using the sugar flotation method and identified. The virus was detected using a BMV-specific direct double antibody sandwich ELISA. Although plant parasitic nematodes were detected in all samples, no Xiphinema spp. were found in relation to any wheat field in which BMV-infected plants occurred. However, in some locations Xiphinema spp. were isolated from soil samples taken from adjacent fields associated with other crops which are not considered hosts for BMV. In Alabama, Xiphinema spp. were not found to be associated with the occurrence of BMV in wheat fields and, therefore, is not the primary vector of this virus.