Comparison of Normal and High-Lysine Maize Inbreds For Resistance to Kernel Rot Caused by Fusarium moniliforme

Abstract

Quantitative differences in resistance to F. moniliforme occurred in both opaque-2 (o2) maize [Zea mays] inbreds and in their normal counter parts. F. moniliforme/maize-inbred interactions were observed among 8 o2 and normal endosperms. Ear rot caused by F. moniliforme was more severe on susceptible o2 maize inbreds than on their normal counterparts. There was little or no difference in kernel rot between resistant o2 and normal isogenic lines. The correlation coefficient between susceptibility to F. moniliforme in o2 and in normal inbreds was 0.62. Susceptibility or resistance in the o2 endosperm was positively correlated with susceptibility or resistance in the normal endosperm. Five mutants (o2, o2 modified, floury-2 (fl2) and double mutant o2/fl2) of inbred W64A were inoculated at different times after pollination. Floury-2 and o2/fl2 were most susceptible to F. monilifore 1 and 7 days past pollination. The other mutants were most susceptible 7 and 14 days past pollination. A method for inocualtion of maize ears with F. moniliforme for differentiation of reactions to Fusarium kernel rot is described. A high incidence of infection and clear differential effects were observed when ears were inoculated by spraying the silk 6-18 days past pollination. Inoculations made 23 days or more past pollination resulted in only a small amount of kernel rot.