Author(s)

Marcel Muengula-Manyi, Lyna Mukwa, Kabwe K. Nkongolo, Patrick Tshilenge-Djim, Stephan Winter, Claude Bragard, Adrien Kalonji-Mbuyi

1Unit of Phytopathology, Faculty of Agronomy, University of Kinshasa, Kinshasa, Democratic Republic of Congo.
Department of Biology, Laurentian University, Sudbury, Canada.
Earth and Life Institute, Applied Microbiology-Phytopathology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
Plant Clinic of Kinshasa, Kinshasa, Democratic Republic of Congo.
Plant Virus Collection, DSMZ Deutsche Sammlung von Mikroorganismen und Zellkuturen GmbH, Braunschweig, Germany.
Regional Nuclear Energy Center, Kinshasa, Kinshasa, Democratic Republic of Congo.
Unit of Phytopathology, Faculty of Agronomy, University of Kinshasa, Kinshasa, Democratic Republic of Congo.

The responses of eight genetically improved and eight local cassava varieties to cassava mosaic disease (CMD) were evaluated under field conditions at two sites, in Eastern Kasa?, region of the DR-Congo). The varieties were planted using randomized complete block design with three replications. The rate of cuttings sprouted varied significantly from variety to variety and from location to location. Local varieties were severely infected than improved varieties throughout the trial period. In general, the level of CMD incidence for genetically improved varieties was below 15% while it reached 100% for the local cassava varieties six months after planting (MAP). This trend was also observed for the CMD severity and gravity. The mean scores for CMD severity were 2 and 3.6 for genetically improved and local varieties, respectively at 6 MAP. CMD gravity for improved varieties was below 21% for genetically improved varieties and exceeded 85% for local varieties at the end of trials. Area Under the Severity index Progress Curve (AUSiPC) and Area Under Disease Progress Curve (AUDPC) estimates confirmed that improved varieties were moderately infested comparatively to local varieties. Molecular analysis is being conducted to determine the genetic variability and complexity of the cassava mosaic virus strains involved.

Cassava Mosaic Disease; Local Cassava Varieties; Genetically Improved Cassava Varieties; AUSiPC; AUDPC; Disease Index; DR-Congo

Muengula-Manyi, M. , Mukwa, L. , Nkongolo, K. , Tshilenge-Djim, P. , Winter, S. , Bragard, C. and Kalonji-Mbuyi, A. (2013) Assessing Reactions of Genetically Improved and Local Cassava Varieties to Cassava Mosaic Disease (CMD) Infection in a Savannah Region of the DR-Congo. American Journal of Plant Sciences, 4, 824-837. doi: 10.4236/ajps.2013.44101.