Field and Molecular Evaluation of Resistance of Iranian Bread Wheats to Fusarium Head Blight

Fusarium Head Blight is a critical wheat disease in Iran, particularly in the provinces of;Mazandaran, Golestan, Ardabil (Moghan) and Fars. The main casual agent of this disease is the fungus Fusarium graminearum. Primary evaluation of 3350 bread wheat accessions of National Plant Gene Bank of Iran to FHB, revealed that some of them were resistant. Twenty two resistant samples along with 1 resistant check and 1 susceptible check derived from primary selection were evaluated using RCBD with 3 replications surrounded by the spreader in Gharakhil Research Station, Sari in autumn 2002. Five severe casual isolates of Fusarium were used for the resistance evaluation. Five times of spray inoculation were applied on the samples just before sunset, in which the concentration of inocula was 3×104 macro conidia/ml. The main agronomic traits were evaluated. The plant pathogen interaction characters, disease index, disease incidence and Fusarium damaged kernels were evaluated three times 10, 14 and 18 days after inoculation.Disease intensity area under the disease progress curve (AUDPC) was also calculated. Theresults revealed that several samples were resistant to disease compared to resistant check. Cluster analysis showed that the resistant accessions were grouped in the same cluster with the resistant check, Sumai#3. For achievement of markers linked to resistance, ten SSR primer pairs were applied. The samples produced different band patterns; however the primers GWM234, GWM251 and GWM340 were informative. They may be able to discriminate resistant samples through optimizing lab conditions and further trials.