Reaction of Some Sorghum Varieties Against Grain Mold and Fumonisin Accumulation

Grain mold caused by Fusarium verticillioides is one of the most dangerous food and feed safety challenges in sorghum production. The most efficient solution for reducing the hazards of the disease is breeding resistant varieties. In order to find the resistant sorghum varieties, nine sorghum varieties were evaluated for their reaction to F. verticillioides and fumonisin accumulation in their kernels under field conditions in Ardabil Agricultural Research Station, Moghan region, Iran (39° 41' N 47° 32' E, with 40-50 m above sea level), using a randomized complete block design with three replications. For artificial inoculation, sorghum panicles were sprayed with the mixture of spore suspension at 50% flowering stage. Two months after inoculation, disease severity was evaluated based on disease progress in each panicle. In addition, total fumonisin produced on sorghum kernels was measured using ELISA kits. The results showed that among studied varieties, KGS12 and KGS15 were moderately resistant and the other eight varieties were highly susceptible or susceptible to grain mold. The mean grain yield under artificial infection showed a reduction of 46.2% in comparison to the natural infection condition (control). The fumonisin accumulation in grains varied from 0.35 ppm (in KGS11 variety) to 1.83 ppm (in Sepideh variety) at the artificial infection condition, while the range was from 0 ppm (in the Kimia variety) to 0.16 (in the KGS15 variety) at the natural infection condition. The mean fumonisin accumulation under natural and artificial infection conditions was 0.07 and 1.00 ppm, respectively, which showed an increase of 1328% in comparison to the control treatment. In general, KGS12 and KGS15 were identified as superior varieties due to their lower disease severity and fumonisin accumulation and acceptable grain yield as compared with other varieties.