family and SSR markers) (Akinbo 200

family and SSR markers) (Akinbo 2008) and are in the
same region of QTLs identified by Okogbenin (2004)
in his study. Also, two of the nine markers (SSRY 250
and ESTs[SSRY 47]) are on linkage group 7 while
SSRY 63, SSRY 106 and SSRY 239 are on linkage
groups 8, 12 and 19, respectively. The remaining four
markers are yet to be placed on any existing cassava
genomic map. The different locations of the identified
QTLs (as indicated by the linkage groups on which the
associated markers are located) on the cassava genetic
map is indicative of the polygenic nature of the trait
studied as also observed by Okogbenin (2004).
Higher correlation coefficients were observed
between the genotypic and phenotypic data at bulk
opening stage than what was observed when the
candidate markers were tested among other genotypes
in each population. This indicates that there was more
noise among the remaining genotypes which lied
between the two extremes (contrasting bulks) in the
rank based on fresh root yield and other traits
associated with EB in each population. The fact that