Improved quantification of Fusarium pseudograminearum (Fusarium crown rot) using qPCR measurement of infection in multi-species winter cereal experiments

Andrew Milgate; Brad Baxter; Steven Simpfendorfer; Herdina; Daniele Giblot-Ducray; Nannan Yang; Beverly Orchard; Ben Ovenden

doi:10.3389/fpls.2023.1225283

Improved quantification of Fusarium pseudograminearum (Fusarium crown rot) using qPCR measurement of infection in multi-species winter cereal experiments

Front Plant Sci. 2023 Aug 2:14:1225283. doi: 10.3389/fpls.2023.1225283. eCollection 2023.

Authors

Andrew Milgate¹, Brad Baxter¹, Steven Simpfendorfer², Herdina³, Daniele Giblot-Ducray³, Nannan Yang¹, Beverly Orchard¹, Ben Ovenden¹

Affiliations

¹ NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, Australia.
² NSW Department of Primary Industries, Tamworth Agricultural Institute, Tamworth, NSW, Australia.
³ South Australian Research and Development Institute, Plant Research Centre, Urrbrae, SA, Australia.

Abstract

Fusarium crown rot (FCR) causes significant grain yield loss in winter cereals around the world. Breeding for resistance and/or tolerance to FCR has been slow with relatively limited success. In this study, multi-species experiments were used to demonstrate an improved method to quantify FCR infection levels at plant maturity using quantitative PCR (qPCR), as well as the genotype yield retention using residual regression deviation. Using qPCR to measure FCR infection allowed a higher degree of resolution between genotypes than traditional visual stem basal browning assessments. The results were consistent across three environments with different levels of disease expression. The improved measure of FCR infection along with genotype yield retention allows for partitioning of both tolerance and partial resistance. Together these methods offer new insights into FCR partial resistance and its relative importance to tolerance in bread wheat and barley. This new approach offers a more robust, unbiased way to select for both FCR traits within breeding programs. Key message: Genetic gain for tolerance and partial resistance against Fusarium crown rot (FCR) in winter cereals has been impeded by laborious and variable visual measures of infection severity. This paper presents results of an improved method to quantify FCR infection that are strongly correlated to yield loss and reveal previously unrecognised partial resistance in barley and wheat varieties.

Keywords: Fusarium crown rot (FCR); barley; partial resistance; qPCR; tolerance; wheat.

Grants and funding

This study was conducted as a co-investment between the NSW Department of Primary Industries and the Grain Research and Development Corporation, under project DAN00175.