Brown Mustard Hybrid Variety: AAC Brown 18
by Dr. Bifang Cheng, Research Scientist, Agriculture and Agri-food Canada
Brown and oriental mustards (Brassica juncea) are used as a vegetable, condiment and oilseed. They originated from the interspecific hybridization between field mustard (B. rapa) and black mustard (B. nigra). In Canada, brown and oriental mustards are grown as condiment mustard crops in the western provinces. Pedigree selection has been used as a major breeding method for cultivar development since it is a self-fertilized crop.
Quality traits, such as protein and oil content, have been improved via the pedigree breeding system, but the seed yield of B. juncea has remained stagnated until recent hybrid breeding breakthroughs. Hybrid breeding has successfully led to the increase in seed yields in canola (B. napus) and the same strategy can be used to substantially increase the seed yield of condiment mustards.
The Agriculture and Agri-Food Canada Saskatoon Research and Development Centre (AAFC-SRDC) has developed an improved breeding technique (Ogura cytoplasmic male sterility restorer line) that has drastically reduced the number of undesirable traits linked to the desirable ones. AAC Brown 18 is the first brown mustard hybrid variety developed using the improved Ogura cytoplasmic hybrid system at AAFC-SRDC.
AAC Brown 18 was registered in Canada and assigned registration number 8592 by the CFIA on August 31, 2018. AAC Brown 18 has significantly higher (21%) yield than the check variety Centennial Brown. Like the check variety, Amigo, it is resistant to white rust race 2a of which Centennial Brown is susceptible. In conclusion, AAC Brown 18, like Centennial Brown, is well adapted to all mustard growing areas in western Canada.
Furthermore, Oriental mustard test hybrids were developed and evaluated in the Mustard Adaption Test in 2019 and showed 20% – 29% higher yields than the check variety Cutlass.
In conclusion, hybrid breeding based on the improved Ogura cytoplasmic system has successfully led to breaking the yield plateau that had existed for 40 years in condiment mustard breeding in Canada.