International Symposium on Cereal Leaf Blights 2019 | University College Dublin, Ireland | 22-24 May 2019

Interactions between Ramularia collo-cygni and barley leaf physiology

Clarinda Burrell*
Scotland's Rural College and University of Edinburgh

Ian Bingham
Scotland's Rural College

Neil Havis
Scotland's Rural College

Steven Spoel
University of Edinburgh

Oral Presentation
Host-Pathogen Interactions

Moore Auditorium, UCD O'Brien centre for Science
23 May 2019, 12:40

View this abstract online by visting

Barley yield can be reduced by Ramularia Leaf Spot (RLS) disease which is caused by the fungus Ramularia collo-cygni (Rcc). Rcc can be present in barley throughout the life of the plant, but disease symptoms don’t usually occur in the field until after flowering. Although there have been significant advances in our understanding of the barley – Rcc relationship in recent years, the nature of the interactions between plant and fungus during the long period before disease symptoms appear is still not well understood. More specifically it is not known to what extent photosynthesis and plant growth is restricted during the asymptomatic phase of pathogen growth. My project aims to answer whether infection with Rcc affects barley leaf physiology during the period before visible disease symptoms appear, and if so whether there is any indication that effects from this stage of infection with Rcc could contribute to yield loss. I have used techniques such as qPCR, infra-red gas analysis, and chlorophyll fluorescence imaging to determine the relationship between the amount of pathogen infection, the severity of visible symptoms, and the rates of leaf photosynthesis and net carbon assimilation in both the symptomless phase and symptom expressing phases of pathogen growth. My results so far show that there is no indication of significant damage to the photosynthetic apparatus before symptom appearance, making it unlikely that the asymptomatic stage of infection is a major contributor to yield loss, however, once symptoms appear effects on photosynthetic performance extend beyond the lesion area.