DisplayTitle

Genetic Structure of Fusarium pseudograminearum Populations from the Australian Grain Belt

First, third, and fourth authors: Faculty of Agriculture, Food and Natural Resources, The University of Sydney, NSW 2006 Australia; second author: Department of Plant Pathology, 4002 Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS 66506-5502; and third and fifth authors: Botanic Gardens Trust, Mrs. Macquaries Road, Sydney, NSW 2000, Australia.

Crown rot, caused by the fungus Fusarium pseudograminearum (teleomorph Gibberella coronicola) is a major disease of wheat in the Australian grain belt. However, there is little information available on the population structure of this pathogen. We measured genetic diversity as assessed with amplified fragment length polymorphism (AFLP) analysis within and between populations of F. pseudograminearum from northeastern, south central, and southwestern regions of the Australian grain belt. Amongst the 217 isolates, 176 haplotypes were identified and grouped into two main clusters. One cluster contained isolates from populations in northeastern Australia, and the other cluster contained isolates from populations in south central and southwestern Australia. The southern populations were distinguished from the northeastern populations by higher levels of population differentiation (G_st) between them and genetic identity amongst the regional populations. We hypothesize that the F. pseudograminearum populations from northeastern and southern Australia are independent, which could result from different founding events or from geographic isolation and the accumulation of genetic differences due to genetic drift and/or selection.

Additional keywords:soilborne diseases, Triticum aestivum.