TITLE:
Genetic Structure and Diversity Study of Cassava (Manihot esculenta) Germplasm for African Cassava Mosaic Disease and Fresh Storage Root Yield
AUTHORS:
Janatu Veronica Sesay, Aiah Lebbie, Richard Wadsworth, Ephraim Nuwamanya, Souleymane Bado, Prince Emmanuel Norman
KEYWORDS:
Population Structure, Genetic Variability, GWAS, SNP Markers, Cassava
JOURNAL NAME:
Open Journal of Genetics,
Vol.13 No.1,
March
14,
2023
ABSTRACT: 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.