Author(s)

Janatu Veronica Sesay^1,2, Aiah Lebbie², Richard Wadsworth², Ephraim Nuwamanya³, Souleymane Bado⁴, Prince Emmanuel Norman^1*

¹Sierra Leone Agricultural Research Institute, PMB 1313, Tower Hill, Freetown, Sierra Leone.
²Department of Biological Sciences, School of Environmental Sciences, Njala University, Njala, Sierra Leone.
³Makerere University Kampala, Kampala, Uganda.
⁴Department of Plant Science, Phytoprise GmbH, DI Rudolf Schober-StraBe 4 7400 Oberwart, Oberwart, Austria.

A better understanding of population structure and genetic diversity among cassava germplasm for African cassava mosaic disease and fresh root yield traits is useful for cassava improvement programme. Phenotype-based selection for these traits is cumbersome due to phenotypic plasticity and difficulty in screening of phenotypic-induced variations. This study assessed quantitative trait loci (QTL) regions associated with African cassava mosaic disease (ACMD) and fresh storage root yield (FSRY) in 131 cassava (Manihot esculenta) genotypes using a genome-wide association study (GWAS). The single nucleotide polymorphism (SNP) loci and associated candidate genes, when validated, would be a valuable resource for marker-assisted selection in the breeding process for development of new cassava genotypes with improved resistance to ACMD and desirable high root yield. Population structure analysis using 12,500 SNPs differentiated the 131 genotypes into five distinct sub-groups (K = 5). Marker-trait association (MTA) analysis using the generalized linear model identified two QTL regions significant for ACMD and three for FSRY. This study demonstrated that DArTseq markers are useful genomic resources for genome-wide association studies of ACMD and FSRY traits in cassava for the acceleration of varietal development and release.

Population Structure, Genetic Variability, GWAS, SNP Markers, Cassava

Sesay, J. , Lebbie, A. , Wadsworth, R. , Nuwamanya, E. , Bado, S. and Norman, P. (2023) Genetic Structure and Diversity Study of Cassava (Manihot esculenta) Germplasm for African Cassava Mosaic Disease and Fresh Storage Root Yield. Open Journal of Genetics, 13, 23-47. doi: 10.4236/ojgen.2023.131002.