Understanding the genetics of solid-stemmed wheat

Growing solid-stemmed wheat varieties is the most common way to prevent wheat stem sawfly damage, which causes approximately $350 million in losses in North America each year. A recent study by the Crop Development Centre, the National Research Council, the Global Institute for Food Security, the Swift Current Research and Development Centre, the National Institute of Agricultural Botany, and the Canadian Grain Commission’s Grain Research Laboratory examined genes linked to stem solidness in wheat. By identifying the genes that cause stem solidness, researchers hope to support the development of new varieties of wheat with the resistance and resilience to thrive in changing climate conditions.

As its name suggests, the wheat stem sawfly is a pest that feeds on the stems of durum and bread wheat. The wheat stem stores and transfers water, minerals, starch and water-based carbohydrates that are linked to higher yields and can preserve quality in hot and dry conditions. Stem solidness reduces the risk of wheat stem sawfly damage by preventing larvae from growing inside the wheat stem.

The researchers studied the differences in the same group of genes in hollow-stemmed and solid-stemmed varieties of durum. They narrowed these genes down to one gene that showed consistent variation between the varieties. Further testing supported the correlation between this gene and the stem solidness trait.

These findings could contribute to the development of genetic markers, which breeders could use to select genes to improve stem solidness in bread wheat and durum. Increased defense against wheat stem sawfly would help protect producers from yield losses, enable crops to better withstand climate challenges and promote sustainability in global food production.