Abstract:

Gene action and heritability of blast between
GULU E as female parent mated to susceptible crossing
design to determine nature of resisto valiationn was done
most virulentlocal pathogen isolate NGR1 ideuULL d from Ngora in Odw.i.
hotspots of eastern agro-rcology Ui.jand, U was identiikd of the pathogen screening trial for
virulence in Makercre University during 2012 B. The
crosses were evaluated
under controlled conditions ana disease reaction indicated that re;.is.ace is parliaily dominant
and additive based on mid parent values from crosses. Segregating ruiios aad chi-square tests of
F, populations fitted 13R:3S genetic niodeL indicating presenceH' duplicate dominunt epistasis
at probability level of 0.05. Broad-sense hcritability estimated by variance components method
was high at about 88.8% on entry mean basis. Selection for resistant progeny derived from
crosses between GULU-E and DR21 would be most effective in early generations followed by
modified backcrossing at F, to the adapted recurrent resistant parent leading to diversification of
a population and derivation of materials for selection for disease resistance. From the study it is
possible to accumulate genes for race specific resistance in host cultivars that might reduce
development of disease epidemics in some areas. The genetic control of components of resistance
and mechanisms of resistance in the host which affect the rate of development of a disease
epidemic need to be determined, since they are important variables for durable resistance