Genome-wide association studies identify genetic loci for apple blotch symptom development

Authored by

Sophie Richter, Monika Höfer, Henryk Flachowsky, Anne Bohr, Sascha Buchleither, Thomas Debener, Andreas Peil, Thomas Wöhner

Abstract

Apple blotch disease caused by Diplocarpon coronariae poses a significant threat to apple production, particularly in low-input production systems. The fungus spreads on leaves, resulting in symptoms such as chlorosis, necrosis, premature defoliation and fruit spots, which severely reduce the yield when infestation occurs in early summer. Apple cultivars are susceptible to apple blotch; however, differences in susceptibility have been identified, as symptom development differs in a temporal manner. Apple blotch symptom progression data from laboratory experiments of 555 apple cultivars was used to conduct a genome-wide association study for the identification of regions in the apple genome associated to symptom delay. This study identified SNP markers associated with a delay in symptom development, with strong significant associations on chromosome 12, as well as on chromosomes 3, 13, and 16. The high heritability of the analyzed traits and the association of the genetic markers with several phenotypic traits highlight the potential for marker-assisted selection for this disease. These results support the development of sustainable breeding strategies for disease-resistant apple cultivars.

Details

Organisation(s)
Section Molecular Plant Breeding
Institute of Plant Genetics
External Organisation(s)
Julius Kühn Institute (JKI) Federal Research Centre for Cultivated Plants
Lake Constance Research Station for Fruit Cultivation (KOB)
Type
Article
Journal
Physiological and Molecular Plant Pathology
Volume
139
ISSN
0885-5765
Publication date
09.2025
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Genetics, Plant Science
Electronic version(s)
https://doi.org/10.1016/j.pmpp.2025.102785 (Access: Closed )