AUTHOR=Cantila Aldrin Y. , Thomas William J.W. , Saad Nur Shuhadah Mohd , Severn-Ellis Anita A. , Anderson Robyn , Bayer Philipp E. , Edwards David , Van de Wouw Angela P. , Batley Jacqueline 

TITLE=Identification of candidate genes for LepR1 resistance against Leptosphaeria maculans in Brassica napus

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1051994

DOI=10.3389/fpls.2023.1051994

ISSN=1664-462X

ABSTRACT=<p>Utilising resistance (<italic>R</italic>) genes, such as <italic>LepR1</italic>, against <italic>Leptosphaeria maculans</italic>, the causal agent of blackleg in canola (<italic>Brassica napus</italic>), could help manage the disease in the field and increase crop yield. Here we present a genome wide association study (GWAS) in <italic>B. napus</italic> to identify <italic>LepR1</italic> candidate genes. Disease phenotyping of 104 <italic>B. napus</italic> genotypes revealed 30 resistant and 74 susceptible lines. Whole genome re-sequencing of these cultivars yielded over 3 million high quality single nucleotide polymorphisms (SNPs). GWAS in mixed linear model (MLM) revealed a total of 2,166 significant SNPs associated with <italic>LepR1</italic> resistance. Of these SNPs, 2108 (97%) were found on chromosome A02 of <italic>B. napus</italic> cv. Darmor bzh v9 with a delineated <italic>LepR1</italic>_mlm1 QTL at 15.11-26.08 Mb. In <italic>LepR1</italic>_mlm1, there are 30 resistance gene analogs (RGAs) (13 nucleotide-binding site-leucine rich repeats (NLRs), 12 receptor-like kinases (RLKs), and 5 transmembrane-coiled-coil (TM-CCs)). Sequence analysis of alleles in resistant and susceptible lines was undertaken to identify candidate genes. This research provides insights into blackleg resistance in <italic>B. napus</italic> and assists identification of the functional <italic>LepR1</italic> blackleg resistance gene.</p>