title: Magnetic resonance imaging of sugar beet taproots in soil reveals growth reduction and morphological changes during foliar Cercospora beticola infestation.
abstract: Cercospora leaf spot (CLS) infection can cause severe yield loss in sugar beet. Introduction of Cercospora-resistant varieties in breeding programmes is important for plant protection to reduce both fungicide applications and the risk of the development of fungal resistance. However, in vivo monitoring of the sugar-containing taproots at early stages of foliar symptoms and the characterization of the temporal development of disease progression has proven difficult. Non-invasive magnetic resonance imaging (MRI) measurements were conducted to quantify taproot development of genotypes with high (HS) and low (LS) levels of susceptibility after foliar Cercospora inoculation. Fourteen days post-inoculation (dpi) the ratio of infected leaf area was still low (~7%) in both the HS and LS genotypes. However, during this period, the volumetric growth of the taproot had already started to decrease. Additionally, inoculated plants showed a reduction of the increase in width of inner cambial rings while the width of outer rings increased slightly compared with non-inoculated plants. This response partly compensated for the reduced development of inner rings that had a vascular connection with Cercospora-inoculated leaves. Hence, alterations in taproot anatomical features such as volume and cambial ring development can be non-invasively detected already at 14 dpi, providing information on the early impact of the infection on whole-plant performance. All these findings show that MRI is a suitable tool to identify promising candidate parent lines with improved resistance to Cercospora, for example with comparatively lower taproot growth reduction at early stages of canopy infection, for future introduction into breeing programmes.
authors: Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften, IBG-2: Plant Sciences, Wilhelm-Johnen-Straße, D-52425 Jülich, Germany simone.schmittgen@julumni.fz-juelich.de s.jahnke@fz-juelich.de.
authors: Simone
authors: S
authors: Schmittgen
authors: Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften, IBG-2: Plant Sciences, Wilhelm-Johnen-Straße, D-52425 Jülich, Germany.
authors: Ralf
authors: R
authors: Metzner
authors: Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften, IBG-2: Plant Sciences, Wilhelm-Johnen-Straße, D-52425 Jülich, Germany.
authors: Dagmar
authors: D
authors: Van Dusschoten
authors: Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften, IBG-2: Plant Sciences, Wilhelm-Johnen-Straße, D-52425 Jülich, Germany.
authors: Marcus
authors: M
authors: Jansen
authors: Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften, IBG-2: Plant Sciences, Wilhelm-Johnen-Straße, D-52425 Jülich, Germany.
authors: Fabio
authors: F
authors: Fiorani
authors: Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften, IBG-2: Plant Sciences, Wilhelm-Johnen-Straße, D-52425 Jülich, Germany simone.schmittgen@julumni.fz-juelich.de s.jahnke@fz-juelich.de.
authors: Siegfried
authors: S
authors: Jahnke
authors: Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften, IBG-2: Plant Sciences, Wilhelm-Johnen-Straße, D-52425 Jülich, Germany.
authors: Uwe
authors: U
authors: Rascher
authors: Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften, IBG-2: Plant Sciences, Wilhelm-Johnen-Straße, D-52425 Jülich, Germany.
authors: Ulrich
authors: U
authors: Schurr
mesh_terms: D001203:Ascomycota / Q000502:physiology*; D027461:Beta vulgaris / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000382:microbiology; D058506:Cambium / Q000033:anatomy & histology / Q000254:growth & development / Q000382:microbiology; D008279:Magnetic Resonance Imaging; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development / Q000382:microbiology
keywords: Beta vulgaris; Cercospora beticola; Cercospora leaf spot; magnetic resonance imaging (MRI); morphological taproot changes; non-invasive phenotyping.