| dc.description.abstract | Exotic germplasm is known to improve productivity and variability of the locally adapted
populations, however little has been done to assess gains that could be attained after genetic
integrations in the CIMMYT-Zimbabwe maize breeding program. The objectives of the
experiment were to: (i) identify high yielding and stable single cross hybrids of the local (i.e.,
CIMMYT-Zimbabwe lines) and the exotic lines; and, (ii) to estimate the combining abilities
of the local and the exotic inbred lines. In this study, exotic inbred lines sourced from the
CIMMYT’s temperate (T), tropical (E) and sub-tropical (S) breeding programs were crossed
with the CIMMYT-Zimbabwe (L) elite lines, using the partial diallel mating design. The 91
singe-cross hybrids (F1s) generated were evaluated together with nine (9) commercial check
hybrids in multi-environmental trials (METs) at eight locations, representing the diverse
maize growing conditions in Zimbabwe. MET data showed differences in grain yield (GY)
performance of the singe-cross hybrids in some of the sites. Significant effects of the
environment in hybrid performance was also detected (GEI; p < 0.05). Crosses between the
local and temperate inbred lines (LXT) showed the highest GY potential (e.g., G55; GY =
10.2924 t/ha) compared to the other crosses. Apart from showing high GY potential, hybrids
from this combination also demonstrated to; be stable in diverse environments, to mature
earlier than the best commercial check hybrids. In conclusion, incorporation of exotic genes,
especially those with a temperate background, may improve the yielding ability and stability,
and can introduce earliness in maturity in the local maize populations (i.e., sub-tropical maize
populations). | en_ZW |
