Effectiveness of partial resistance sources in hexaploid wheats against fusarium pseudograminearum isolates

Abstract

[Introduction]: Crown rot occurs in all wheat growing regions of Australia. While it has been demonstrated that infection with Fusarium pseudograminearum is the predominant cause of crown rot in Australian wheat crops, no studies have been conducted to determine whether differences in the pathogenicity of this fungus occur between different isloates when grown on partially resistant genotypes. An understanding of this issue is important for two main reasons. Firstly, the occurrence of pathotypes in the Australian environment against which current sources of resistance are ineffective would severely reduce their long-term usefulness. Secondly, the molecular markers that are being developed for marker assisted selection of crown rot resistance are based upon phenotypic data obtained from host responses to a mixed inoculum, and thus may only prove useful for selecting lines that show effective resistance to a subset of isolates in the environment. In this study we have challenged a selection of partially resistant host genotypes with a range of pathogen isolates from across Australia.