Ms Denise Barbulescu1, Dr Joshua C. O. Koh1, Assoc. Prof. Phil A. Salisbury1, Dr Surya Kant1,2
1DJPR- Agriculture Victoria, HORSHAM, Australia,
2School of Applied Systems Biology, La Trobe University, Bundoora, Australia
Blackleg disease caused by the fungus Leptosphaeria maculans can result in significant yield losses in canola (Brassica napus) in Australia and worldwide. Genetic resistance to blackleg in canola cultivars can be easily eroded leading to crop failure. As a result, there is a constant need to discover novel sources of blackleg resistance, particularly in Brassica species closely related to canola. Seedling resistance to blackleg has been discovered in the A- and B-genomes of Brassica, with recent discoveries reported in the C-genome. This study aimed to identify novel sources of blackleg resistance in the C-genome of B. oleracea and examine their effectiveness in the Australian field environment.
Resistant accessions were identified from 37 diverse B. oleracea accessions following an initial screening with two single spore L. maculans isolates. These were further characterized using a differential set of 16 single spore isolates and evaluated in field trials across two locations over two years. Two B. oleracea accessions showed phenotypic resistance patterns in seedlings identical to known major Rlm genes in canola, and had effective blackleg field resistance in one or both sites.
The identification of these putative novel blackleg resistance genes allows their introduction into canola in pre-breeding and breeding programmes.
Denise Barbulescu is a research scientist at Agriculture Victoria, Australia, where she has been working on canola trait improvement since 2003. Denise has Bachelor and Honours degrees in Biomedical Sciences from the University of South Australia. She has been instrumental in optimising and scaling up the doubled haploid program for Brassica napus and Brassica juncea in early 2000s. Since 2010, Denise’s research has been in the discovery of novel major genes for resistance to blackleg and, in evaluating the quantitative resistance to blackleg in Australian cultivars, working across national, state, and private research projects. Denise has also been involved in projects evaluating agronomical traits in canola and wheat.