Drought tolerant maize (Zea mays L.) hybrids are crucial for the sustainability of maize production in the drought-prone areas of Sub-saharan Africa. Understanding the genetics of inheritance under drought is important in designing breeding strategies for improving grain yield and other agronomic traits under drought. Two studies were conducted to determine the the genetic variability and mode of gene action for grain yield and other traits of different maturity groups of maize inbreds for tolerance to drought and identify the promising drought-tolerant maize hybrid(s) for drought-prone regions. Eleven inbred lines of different maturity groups and endosperm-modification were crossed using diallel mating scheme to generate 55 F1 hybrids. The 55 hybrids along with one check and 11 inbreds were separately evaluated under induced drought and optimum growing conditions at Samaru and Kadawa. The experiments were laid in a 7 x 8 alpha lattice design and replicated two times using single-row plot of 4-m long. Row and hill spacing were 0.75 m and 0.4 m respectively. General combining ability (GCA) and Specific combining ability (SCA) mean squares were significant (p < 0.01) for grain yield and most other traits under drought and optimum growing conditions. SCA accounted for 79.3% and 64.2% of the total genetic variation for grain yield under drought and optimum growing conditions, indicating that non-additive gene action largely controlled the inheritance of grain yield of the hybrids. Hybrid TZEE-W-Pop STR C5 x TZEI 87 should be further tested in multiple environments for adoption by farmers in drought prone areas of Sub-saharan Africa.

Drought tolerance, Diallel design, Combining ability, Gene action

agronomy

Presentation: poster