Enhancing traits of agronomic and economic importance in wheat

小麦是加拿大最重要的经济作物之一。然而，它的生产不断受到各种因素的挑战，包括收获前种子在母株上萌发的收获前发芽(PHS)，以及由于大风和大雨而倒伏的作物，通常在出穗后倒下。这些因素综合在一起，导致粮食产量和品质显著下降，给小麦生产者造成了巨大的经济损失。商业小麦生产中倒伏的发生与氮肥使用量的增加有关，氮肥的使用对于获得更高的产量是必不可少的。尽管化学生长调节剂可以控制作物高度并缓解倒伏问题，但由于其对生产者的巨大额外成本以及相关的环境和食品安全问题，它们的使用是不可持续的。大多数商业小麦品种都是通过抗种子休眠来获得快速、均匀的萌发和快速立地的，因此在收获前潮湿的条件下，它们容易受到PHS的影响。随着气候变化，有利于小灵通的环境条件的严重性和频率预计会增加。因此，加拿大小麦生产者一直在寻找耐倒伏和PHS的小麦品种。种子休眠和茎高/茎强主要由植物激素调节；然而，小麦中潜在的分子机制却知之甚少。小麦品种间PHS和耐倒性的差异也可归因于分别对种子休眠和茎高/强度起关键调节作用的遗传因素。然而，控制小麦这些性状的遗传机制还很少被研究。这项拟议的研究旨在确定可作为基因组工具的新基因/等位基因，以促进小麦育种提高对PHS和倒伏的耐受性，从而提高产量和品质，并最大限度地提高加拿大小麦生产者的经济效益。

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.