Besides stem canker severity, oilseed rape host genotype matters for the production of Leptosphaeria maculans fruit bodies. (August 2021)

• Record Type: Journal Article
• Authors: Bousset, Lydia; Vallée, Patrick; Delourme, Régine; Parisey, Nicolas; Palerme, Marcellino; Leclerc, Melen
• Is Part Of: Fungal ecology. Volume 52(2021)
• Publication Date: 2021-08
• Subjects: Blackleg -- Disease phenotyping -- Epidemiology -- Image analysis -- Inoculum potential -- Transmission; Fungi -- Ecology -- Periodicals; Mycology -- Periodicals; 579.517
• DOI: 10.1016/j.funeco.2021.101076
• Languages: English
• ISSNs: 1754-5048

Abstract

Abstract: For fungal cyclic epidemics on annual crops, the pathogen carry-over is an important but poorly documented step. Plant resistance affects the pathogen development within the epidemics but we lack data on the inter-annual transmission of inoculum. For Leptosphaeria maculans on 15 oilseed rape genotypes in field during 4 growing seasons, stem canker severity was visually scored at harvest. The number of fruit bodies produced on incubated stubble was quantified using an automated image analysis framework. Our results confirm that fruit body production increases with disease severity and is significantly affected by host genotype and nitrogen supply. Tracking individual stems through incubation, we confirm for the first time that the oilseed rape genotype has a direct effect on inoculum production, not only disease severity. This major effect of genotype on inoculum carry-over should be taken into account in models of varietal deployment strategies. Highlights: We produced data on the effect of plant resistance on pathogen carry-over. Oilseed rape stems were assessed for L. maculans stem canker severity. Fruiting bodies were quantified using an automated image analysis framework. We confirmed that fruiting body production increases with severity at harvest. The oilseed rape genotype has a direct effect on inoculum production, not only through disease severity.