Dipika Roy

Position: Research Assistant (PhD student from 2017)
Place of Birth: Bangladesh
Language: English, Bengali (Bangla)
Scholarships: Australian Government Research Training Program (RTP) Scholarship, Grains Research and Development Corporation (GRDC) Top up scholarship
Advisors: Dr Lee Hickey, Hon. Prof. Gregory Platz, Dr Reginald Lance, Dr Kai Voss-Fels



Spot blotch caused by Bipolaris sorokiniana, is a major foliar disease of barley worldwide. It degrades crop quality (particularly malting quality) and contributes to crop losses in Australia. The infection in seedlings can be identified by dark brown to black spots on leaf sheaths, which progresses from lower to upper leaves during crop development. Oblong and chlorotic margin type lesions are found generally on susceptible adult plants. The deployment of cultivars incorporating genetic resistance to spot blotch would prevent epidemics and create significant value economically and environmentally for the barley industry. However, more knowledge of the genetics of spot blotch resistance and DNA tools are required to effectively assemble useful gene combinations in new cultivars.

·     Identify quantitative trait loci (QTL) underpinning spot blotch resistance in elite breeding populations via Genome Wide Association Studies (GWAS).
·     Identify spot blotch resistance loci in three genetic backgrounds (Compass, Commander and La Trobe) preferred by the barley industry by performing multi parent nested association mapping (NAM)
·     Investigate QTL x background effects and precisely examine QTL combination effects.
·     Investigate diverse barley accessions that could provide spot blotch novel resistance genes that are not present in elite barley germplasm.

Research Outlook:
A total of 338 elite barley lines from the Northern Region Barley (NRB) breeding program, representing Stage 2 entries from 2012 and 2013, were genotyped with 16,824 polymorphic DArTseq markers. GWAS will be performed using phenotype data collected from field screening nurseries and seedling assays evaluating resistance to spot blotch. The number, effect and chromosomal position of key loci conferring resistance to spot blotch will be determined.
Dipika Roy presenting barley spot blotch association mapping work at the Australian Barley Technical Symposium (ABTS) in 2017: