A total of 91 individuals had no marker alleles associated with theCMD2 gene. This would imply that either these individuals have resistance different from the CMD2 gene or that they are false resistant genotypes. The former could apply to individuals which are progenies of Dabodabo and TMEII if CMD resistance in the two genotypes is different from
CMD2 resistance. Further study is still required to confirm resistance in these two genotypes. The latter possibility (false resistant genotypes) would be most probable in individuals with no marker allele for CMD2 derived from crosses between CIAT genotypes
and the susceptible landraces (Afeb and Tuaka). The expected source of CMD resistance for such individuals should be the CMD2 gene from the CIAT donor parents. As the individuals did not have any allele of the four markers used for CMD2 selection, thenCMD2 resistance is most probably not present in these individuals and they may therefore be false resistant genotypes.MAS has been used successfully in cassava
for studying CMD resistance (Fregene et al. 2007;Okogbenin et al. 2007).