Study of inheritance of resistance to fusarium head blight in some Iranian wheat landraces by dialell analysis

The inheritance of resistance to Fusarium Head Blight (FHB) in local wheat accessions of National Plant Gene-Bank of Iran was studied in a 7×7 one-way diallel cross design. Seedlings of F1 and parents were grown in a Randomized Complete Block Design (RCBD) with two replications at Gharakhil research station of Mazandaran in Autumn of 2002. Response to the disease was evaluated as the percentage of infected spikelets and of infected seeds. Diallel analysis was performed by two methods of Griffing، and Jinks and Hayman. General and specific combining ability were significant for both traits. Results of analysis of variance، regression analysis and estimates of genetic parameters indicated the importance of additive، dominance and epistatic gene effects in controlling the resistance to FHB. Narrow-sense heritability of infected spikelets was higher than that of infected seeds، so the trait was suggested as a useful criterion for resistance to FHB. Line No. 5 was of the largest general combining ability for both traits، Therefore it is suggested to be involved in wheat breeding programs for improving resistance to FHB.