Resistance to kernel infection and seedling blight of sweet corn caused by Fusarium moniliforme and Penicillium oxalicum

Poor emergence and vigor of seedlings reduce stands of sweet corn (Zea mays L.), especially among shrunken-2 (sh2) hybrids. Fungal pathogens, environmental factors, and physiological weaknesses of seed affect the performance of sh2 seed and seedlings. Fusarium moniliforme Sheldon (teleomorph: Gibberella fujikuroi (Sawada) WollenW.) and Penicillium oxalicum Currie and Thom are isolated frequently from maize kernels. The objectives of this research were to evaluate two inoculation techniques used to screen seedling reactions of sweet corn inbreds and single cross hybrids to F. moniliforme and P. oxalicum, to determine the inheritance of resistance in the resistant inbred IL125b to kernel infection, to evaluate the effectiveness of resistance against other ear rot fungi, and to determine if resistance to F. moniliforme kernel infection can be transferred by backcrossing. Seed inoculation with spore suspensions of F. moniliforme and P. oxalicum could be used in selection for resistance to the seedling phases of these fungal diseases. A sorghum grain inoculation method appeared to be ineffective in screening for resistance to F. moniliforme and P. oxalicum seedling blight. Four inbreds Ia453, IL352, IL451b, and IL781a were classified resistant to P. oxalicum seedling blight. The resistance to F. moniliforme kernel infection in IL125b was influenced by the genotype of the silks and endosperm, and was controlled by many genes. Additive and dominant gene actions were of primary importance in the inheritance of resistance. The backcross breeding method did not increase resistance of a susceptible inbred to symptomatic and asymptomatic kernel infection when lines were selected for severity to ear rot. Breeding procedure maximizing the accumulation of resistance alleles, such as mass selection or recurrent selection, would be the most effective method of breeding for resistance to F. moniliforme kernel infection.U of I OnlyETDs are only available to UIUC Users without author permissio