about half of the genotypes selecte

about half of the genotypes selected as EB genotypes
using conventional method were true to type when
subjected to genotypic analysis indicates that use of
SSR markers can help breeders select with moderate
precision for desired traits in cassava.
Different favourable alleles are involved in the
control of most important agronomic traits as shown in
this study by the presence of different QTLs associated
with EB in different populations and on different
linkage groups. Therefore, phenotypic selection for
such traits may be less efficient compared to MAS.
MAS therefore makes it possible to perform QTLs
pyramiding i.e. combining QTLs having different
gene actions for a specific trait into one variety. This
will allow a more accurate and efficient selection of
superior genotypes and reduction of time and space at
the early stage of a breeding programme. Identifying
and pyramiding different genes associated with EB in
cassava would lead to development of extra EM
cassava varieties which will fit better into areas with
short growing season and also reduce the period over
which farmers wait before they can get some food/
income from their crops. The molecular markers
identified in this study would therefore allow implementation
of MAS to aid pyramiding of different
genes linked to EB in cassava.
Acknowledgments This study was conducted with funding
support from Kirkhouse Trust Foundation, UK and with support
from University of Ibadan, Nigeria; International Center for
Tropical Agriculture (CIAT), Cali, Colombia; National Root
Crops Research Institute (NRCRI), Umudike; and Generation