Enhancing traits of agronomic and economic importance in wheat

点击翻译按钮获取中文摘要

Wheat is one of the most economically important crops of Canada. However, its production is constantly challenged by a variety of factors including preharvest sprouting (PHS), which refers to germination of seeds on the parent plant prior to harvest, and lodging, which refers to falling over of the crop, often after ear emergence, due to high wind and rain. These factors in combination cause significant reduction in grain yield and quality, incurring high financial loss to wheat producers. The incidence of lodging in commercial wheat production is associated with increased usage of nitrogen fertilizers that is essential for attaining higher yields. Although chemical growth regulators can control crop height and mitigate the problem of lodging, their use is not sustainable due to its considerable additional cost to the producers and the associated environmental and food safety concerns. Most of the commercial wheat cultivars have been selected against seed dormancy to attain fast and uniform germination and rapid stand establishment, and as the result they are susceptible to PHS when wet conditions occur prior to harvest. The severity and frequency of environmental conditions that favor PHS are expected to increase with climate change. As a result, wheat cultivars with tolerance to lodging and PHS are sought by Canadian wheat producers. Seed dormancy and stem height/strength are regulated primarily by plant hormones; however, the underlying molecular mechanisms are poorly understood in wheat. Variation in PHS and lodging tolerance between wheat genotypes can also be attributed to genetic factors that act as key regulators of seed dormancy and stem height/strength, respectively. Nonetheless, the genetic mechanisms controlling these traits in wheat are scarcely studied. The proposed research is aimed at identifying novel genes/alleles that can be deployed as genomic tools to facilitate wheat breeding for enhanced tolerance to PHS and lodging, and thereby improve yield and quality and maximize economic returns to Canadian wheat producers.