Reaction of backcross maize populations to Turcicum leaf blight

Abstract

Five maize cultivars, Longe 1, EV8349-SR, EV Jos (moderately resistant), Gusau TZB-SR and EV8429-SR (susceptible)

were crossed to Population 42, a cultivar with high level of resistance to Exserohilum turcicum, causal agent of turcicum leaf blight. Parental, BC₂and BC₂ populations were inoculated at knee-high stage and evaluated for their reaction to turcicum leaf blight and yield performance at two locations of Uganda, Namulonge and Kabanyolo. EV8428-SR and KWCA were included as susceptible and local checks, respectively. Except for yield and apparent infection rates (r), differences among populations were significant (P < 0.05). The BC] and BC₂ generally had less disease than the parental cultivars, but the results were not consistent. Longel BC], EV8349-SR BC₂ and EV8429-SR BC₂ yielded >7,000 kg ha^-1, while KWCA, the recommended commercial cultivar, yielded 6618 kg ha^-1