Parastagonospora nodorum Assembly. Parastagonospora nodorum

Narrow host-range necrotrophic fungal pathogens in the Pleosporales cause severe diseases in a wide range of agronomically important crops by secreting multiple necrotrophic effectors (NEs).Parastagonospora (syn. Stagonospora; Phaeosphaeria, Septoria) nodorum (Berk.) Quaedvlieg, Verkley & Crous is one such Pleosporalean fungal pathogen, causing septoria nodorum blotch (SNB) of wheat (Triticum spp.) (Quaedvlieg et al., 2013; Solomon et al., 2006). The fungus causes significant damage to the leaves and glumes lowering yield and grain quality. Losses in Australia due to SNB were reported to be an average of 9% or AUD$108 million per annum (Eyal et al., 1987; Murray & Brennan, 2009; Oliver et al., 2009). P. nodorum is widely considered the model Pleosporalean, an order of agronomically significant pathogens that exhibit the inverse gene for gene model (Oliver et al., 2012). The model helps to dissect and elucidate how different disease components contribute to the complexity of disease expression at the molecular level in the Pleosporales (Faris and Friesen 2020; Friesen and Faris 2021; Kariyawasam et al 2023). Expanding from the study by Phan et al 2020, in this study, we identified the population structure of a Western Australian P. nodorum population of 360 isolates consisting of an old collection of 250 isolates collected over a 50-year period (1968-2018) and a current population of 100 isolates isolated in 2019-2021. We confirmed what was previously reported and revealed the same pattern of low-amplitude boom-and-bust cycles in the temporal population.