Development of hormone based genomic tools to accelerate wheat breeding for enhanced preharvest sprouting tolerance

Posted on 06.02.2017 | Last Modified 10.04.2023
Lead Researcher (PI): Belay Ayele
Institution: University of Manitoba
Total WGRF Funding: $116,000
Co-Funders: MAFRD-Agri-Food Research & Development Initiative
Start Date: 2015
Project Length: 3 Years

Development of wheat cultivars with improved tolerance to preharvest sprouting (PHS), emphasizing the need of developing innovative genomic tools for efficient and directed wheat breeding to improve PHS tolerance.

Project Summary:

Wheat is one of the most important crops of Canada. Nationally, wheat contributes from $4 to $5.5 billion to Canada’s
gross domestic product. Given that wheat accounts for 20% of the global calorie consumption and the world’s population
is growing, the market share for high quality Canadian wheat continues to increase significantly. In order to promote fast
and uniform germination, rapid stand establishment and thereby achieve good yield, wheat, like any other domesticated
crops, has been selected against dormancy (where dormancy refers to the inability of viable grains to germinate under
apparent favourable conditions). Because of this selective pressure, the modern wheat cultivars have limited dormancy
and are thus susceptible to preharvest sprouting (PHS) in the field, especially when wet conditions occur along with
physiological and harvest maturity. PHS is one of the abiotic problems challenging Canadian wheat producers as it
causes substantial grain yield and quality losses that incurs high economic cost. Field sprouting of wheat grains is favored
by warm conditions during seed maturation, therefore, the problem is expected to be more prevalent with a warming
climate. Therefore, resistance to PHS is a highly desirable trait sought by the Canadian wheat industry. Given that the
plant hormone gibberellin (GA) and abscisic acid (ABA) are critical regulators of seed dormancy and thereby resistance to
PHS, the key achievements of this project is identification of key ABA and GA metabolism and signaling genes that control
temperature mediated alterations in the levels of ABA and GA in seeds and seed sensitivity to these two phytohormones,
and therefore seed dormancy and PHS resistance levels. Furthermore, the study detected natural variants in genes that
regulate ABA response and thereby seed dormancy in wheat seeds. The study also identified and characterized other
temperature regulated genes that could play crucial roles in the control of seed dormancy and PHS. Using a diverse
wheat germplasm tested over multiple environmental/temperature conditions, we were able to detect one of the
temperature regulated genes whose expression is closely associated with dormancy levels in a specific genomic region of
wheat that contribute to resistance to PHS. The genes and allelic variants identified in this study have the potential of
providing genomic tools such as DNA markers for facilitating the development of PHS resistance wheat cultivars in the
face of climate change-induced warming temperature. My team is closely working/collaborating with wheat breeders to
identifying efficient approaches of deploying the genes/allelic variants identified in this study in their breeding programs.
The development of PHS resistant wheat cultivars will enable wheat producers to provide high yield and quality wheat
sustainably for the Canadian wheat industry and international export markets, thereby maximizing their competitive
advantage. The project also contributed to the training of 13 highly qualified personnel in wheat genomics and molecular
breeding, who are either continuing further training or currently working in the Canadian agricultural industry.