Discovery and genetic mapping of single nucleotide polymorphisms in candidate genes for pathogen defence response in perennial ryegrass (Lolium perenne L.)

• Published in: Theoretical and applied genetics Vol. 117; no. 2; pp. 203 - 219
• Main Authors: Dracatos, P. M, Cogan, N. O. I, Dobrowolski, M. P, Sawbridge, T. I, Spangenberg, G. C, Smith, K. F, Forster, J. W
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.07.2008; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: Agriculture; Base Sequence; Biochemistry; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Cereals; Chromosome Mapping; Classical genetics, quantitative genetics, hybrids; Crosses, Genetic; Disease; Fundamental and applied biological sciences. Psychology; Gene loci; Genes, Plant; Genetics of eukaryotes. Biological and molecular evolution; Immunity, Innate - genetics; Life Sciences; Lolium - genetics; Lolium - immunology; Lolium - microbiology; Methods, theories and miscellaneous; Molecular Sequence Data; Original Article; Pathogens; Plant Biochemistry; Plant Breeding/Biotechnology; Plant Diseases - genetics; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Genetics and Genomics; Polymorphism, Single Nucleotide - genetics; Pteridophyta, spermatophyta; Quantitative Trait Loci - genetics; Quantitative Trait, Heritable; R&D; Research & development; Signal transduction; Vegetals; Australia; Restriction Fragment Length Polymorphism; Single Nucleotide Polymorphism Locus; Perennial Ryegrass; Crown Rust; Resistance QTLs; Genetic mapping; Monocotyledones; Gramineae; Angiospermae; Genetics; Spermatophyta; Agriculture; Candidate gene; Single nucleotide polymorphism; Lolium perenne
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-008-0766-7

Susceptibility to foliar pathogens commonly causes significant reductions in productivity of the important temperate forage perennial ryegrass. Breeding for durable disease resistance involves not only the deployment of major genes but also the additive effects of minor genes. An approach based on in vitro single nucleotide polymorphism (SNP) discovery in candidate defence response (DR) genes has been used to develop potential diagnostic genetic markers. SNPs were predicted, validated and mapped for representatives of the pathogenesis-related (PR) protein-encoding and reactive oxygen species (ROS)-generating gene classes. The F₁(NA₆ x AU₆) two-way pseudo-test cross population was used for SNP genetic mapping and detection of quantitative trait loci (QTLs) in response to a crown rust field infection. Novel resistance QTLs were coincident with mapped DR gene SNPs. QTLs on LG3 and LG7 also coincided with both herbage quality QTLs and candidate genes for lignin biosynthesis. Multiple DR gene SNP loci additionally co-located with QTLs for grey leaf spot, bacterial wilt and crown rust resistance from other published studies. Further functional validation of DR gene SNP loci using methods such as fine-mapping and association genetics will improve the efficiency of parental selection based on superior allele content.