INCIDENCE MOLECULAIRE ET DISTRIBUTION DES VIRUS ASSOCIES A LA MOSAIQUE AFRICAINE DU MANIOC AU SUD-KIVU EN REPUBLIQUE DEMOCRATIQUE DU CONGO.

Cassava Mosaic Disease (CMD) is a dreadful disease of cassava (Manihot esculenta Crantz) production systems in sub-Saharan Africa. The objective of this study was to establish the viruses associated with CMD and their spatio-temporal distribution in the South Kivu Province of the Democratic Republic of Congo. A total of 590 cassava leaf samples were collected during November in 2020 and March 2022 and analysed for laboratory analysis using molecular methods. Results showed that various virus strains (African Cassava Mosaic Virus (ACMV), East African Cassava Mosaic Virus (EACMV), ACMV+EACMV-UG, EACMCV and unspecified strains) were widely distributed in South Kivu. Strain EACMV-UG was widespread in all territories of South Kivu Province; while the Cameroonian strain (EACMCV) was only found in the Kalehe Territory (2%). There was a mixed infection (ACMV+EACMVUG), though at low levels, rising from 2.3% in 2020 to 3% in 2022. All the territories surveyed had wide diversity of viruses, with the exception of that of Uvira, which only had the EACMV-UG. The ACMV viruses were the most abundant; followed by EACMV-UG, in the study region. A sharp increase in virus diversity occurred during 2020 and 2022, with rates rising from 33.07 to 57.5%. [ABSTRACT FROM AUTHOR]