Reaction of Waxy and Opaque-2 Inbreds and their Derived Progenies to Multiple Foliar Diseases of Maize in Uganda

Specialty maize lines possessing important endosperm genes waxy and/or opaque-2 enhance processing and nutritional qualities of the grain. However, production and utilization of specialty maize varieties for food, feeds and various industrial end-uses are constrained by endemic foliar diseases of maize including turcicum leaf blight, gray leaf spot and maize streak virus disease. The purpose of this study was to investigate the reaction of two specialty maize genotypes (waxy and opaque-2) and their derived F1, F2 and backcross progenies to multiple foliar diseases of maize. A randomized complete block design was used to evaluate these materials under field conditions in Uganda. Significant differences among populations were observed for susceptibility to turcicum leaf blight and maize streak virus disease. The opaque-2 inbred CML182 did not manifest any maize streak virus disease symptoms during the assessment period. Significant differences were observed for susceptibility to maize streak virus disease between reciprocal crosses but not for turcicum leaf blight suggesting possible maternal effects associated with maize streak virus disease resistance. Susceptibility to turcicum leaf blight and maize streak virus disease was associated with the recessive endosperm genes (waxy and opaque-2). These results show that developing waxy and opaque-2 specialty maize varieties with good agronomic and grain quality attributes is dependent on the choice of parents carrying important resistance as well as endosperm modifying genes.