Assessment of the Susceptibility to Fusarium Ear Rot of Corn Plants Grown from Seeds of Variety EV 8728 Irradiated with Gamma Rays

This study aimed at determining the effects of various doses of gamma rays on the susceptibility to Fusarium ear rot and the yield parameters of corn seeds of variety EV 8728. The experiment was carried out at the experimental station of the University Jean Lorougnon Guédé on a randomized complete block plot with 3 repetitions. An isolate of local Fusarium sp. local served as the source of contamination. The inoculation technique used was the injection of spore suspensions into the silk channel. Corn kernels were irradiated with 200 and 300 Grays gamma rays, while the unirradiated variety EV 8728 was used as a control. The results showed that the control corn ears were more susceptible to Fusarium ear rot. Their severity (1.59%), intensity (1.51%) and incidence (91.67%) were higher than those of the ears resulting from irradiated seeds, which were respectively 0.52%, 0.49% and 83.33% for 200 Grays doses, and 0.25%, 0.22% and 80.56% for 300 Grays doses. Statistical analysis of these values showed a significant difference (p < 0.01) for susceptibility parameters. As for yield and yield parameters, they were strongly influenced by irradiation. Control plants had higher yields than irradiated plants (p < 0.01), meaning that the 200 and 300 Grays doses inhibited productivity. However, some corn plants were identified whose ears showed resistance to Fusarium ear rot at the 200 Grays dose, and whose yield was statically similar to that of the control. The corn kernels grown from these plants could be the subject of in-depth studies so as to provide starting genitors for a breeding program for corn varieties resistant to Fusarium ear rot.