The genetic structure and aggressiveness of Fusarium pseudograminearum populations in Iran

Crown and root rot of wheat caused by Fusarium pseudograminearum is one of the most important wheat diseases in Iran. In this study, the genetic structure and aggressiveness of four populations of F. pseudograminearum were investigated in five provinces of Iran. Sixty-four isolates of F. pseudograminearum, isolated from samples collected from wheat fields, were examined for genetic diversity and structure, using six simple sequence repeat markers. Fifty-eight haplotypes were identified, indicating that there was a high level of genotype diversity among Iranian isolates of F. pseudograminearum. Most of the variation (90 %) was observed within populations and only 10 % among populations. The greatest genetic similarity was detected between the Qazvin–East Azarbaijan and Lorestan populations, and the greatest genetic distance was between the populations of Lorestan and Golestan. Considerable variations in aggressiveness were observed among 40 isolates of F. pseudograminearum, which had been selected for greenhouse studies. No consistency was observed between the molecular variation and aggressiveness of the isolates. In general, the high genetic diversity accompanied with aggressiveness indicated that both of the aspects should be taken into consideration for resistant breeding program and the development of disease management strategies.