Molecular Identification of Cassava Mosaic Begomoviruses Associated with Cassava Mosaic Disease in the DR-Congo Using Primer Pairs.

Molecular analysis of cassava leaf samples from different regions of the Democratic Republic of Congo (DR-Congo) was conducted to identify cassava mosaic begomoviruses (CMBs) associated with cassava infections in farmers' fields in Gandajika (Eastern Kasai), Bas-Congo and Kinshasa. Four specific primer pairs M1F/M1R, M2F/M2R, Begomo 146/Begomo 672, and EAC4F/EAC4R were used to detect East African cassava mosaic virus (EACMV) AC2, African Cassava Mosaic Virus (ACMV) AC2, ACMV DNA-A, and EACMV-UG DNA-A AC4, respectively. Based on PCR analysis, only African cassava mosaic virus (ACMV) and East African cassava mosaic virus (EACMV-UG) were identified in the cassava growing regions. Overall, 67% of cassava samples were infected with ACMV, 10% with EACMV-UG, and 10% with both, ACMV and EACMV-UG. No virus was detected in 13% of symptomatic samples. Thus, although EACMV-UGG is present in targeted areas, ACMV remained the most common CMB in the DR-Congo.