Validation of Diaporthe toxica resistance markers in European Lupinus angustifolius germplasm and identification of novel resistance donors for marker-assisted selection

• Published in: Journal of applied genetics Vol. 61; no. 1; pp. 1 - 12
• Main Authors: Książkiewicz, M., Wójcik, K., Irzykowski, W., Bielski, W., Rychel, S., Kaczmarek, J., Plewiński, P., Rudy, E., Jędryczka, M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2020; Springer; Springer Nature B.V
• Subjects: Animal Genetics and Genomics; Biomedical and Life Sciences; Blight; Breeding; Collection; Diagnostic systems; Diaporthe toxica; Disease resistance; Endophytes; Field tests; Fungi; Gene pool; Germplasm; Human Genetics; Imperfect state; Inoculation; Life Sciences; Lupins; Lupinus angustifolius; Marker-assisted selection; Markers; Metabolites; Microbial Genetics and Genomics; Phomopsis; Plant diseases; Plant Genetics and Genomics; Plant Genetics • Original Paper; Recombination; Secondary metabolites; Stem blight; Tagging; Poland; Australia; Germany; Molecular breeding; Phomopsis stem blight; Pathogenic fungus; Narrow-leafed lupin; Phr1; PhtjR
• ISSN: 1234-1983; 2190-3883
• DOI: 10.1007/s13353-019-00521-y

The fungus, Diaporthe toxica , anamorph Phomopsis sp., previously classified as P. leptostromiformis , is a plant endophyte and occasional pathogen, causing Phomopsis stem blight. This disease is damaging not only to lupins but also to the animals grazing on infected plants, due to the toxic secondary metabolites called phomopsins. The aim of this work was to validate markers for resistance to Phomopsis stem blight in narrow-leafed lupins and identify novel germplasm with increased levels of resistance to the disease. Plant inoculations were performed using ten isolates of D. toxica , originating from Australia and Poland. The European core collection of L. angustifolius was evaluated both in a controlled environment and with field experiments to classify the accessions based on their resistance to the disease. Simultaneously, the accessions were assayed with disease resistance markers to identify donors of hypothetical resistance alleles. We have found that the European lupin germplasm collection preserves wild and domesticated donors of at least two resistance genes to Phomopsis stem blight, including Phr1 and PhtjR . Molecular markers PhtjM7, InDel2, and InDel10, tagging PhtjR gene, were applicable for marker-assisted selection targeting the European gene pool with an expected accuracy of 95%. None of diagnostic markers for the Phr1 locus was found useful for European breeding programs; two existing markers Ph258M1 and Ph258M2 were unreliable, due to a high percentage of false-positive results (up to 58%) and a high recombination rate between markers (~ 30%).