Improvement of grain yield and quality in climate change resilient crops

上个世纪的高人为活动使大气中二氧化碳含量升高，气温升高，并改变了全球降水模式；这些气候变化对作物生产力构成严重挑战。为了维持粮食和营养安全，需要在世界范围内提高作物产量和改善营养质量。对加拿大来说，需要改进的包括小麦（Triticum aestivum L.），这是人类饮食中的主食，也是加拿大生产商的重要出口商品。***加拿大是一个主要的小麦生产国和出口国，在过去的五年里，平均每年的小麦产量约为3000万吨，出口收入为50亿美元。在加拿大，三个大草原省占有84%的可耕地，是小麦的主要生产地。春小麦（约83%）是加拿大的优势品种。在低冬杀年份，秋种冬小麦的产量比春小麦高20 - 40%。冬小麦也是一种非常环保的作物，因为它有效地利用了春水，成熟早，产量比春小麦高。在过去十年的研究中，利用基因组选择，我们已经确定了与最耐寒的冬小麦品种Norstar相比，耐寒性增强和冬季存活率提高的小麦基因型。我们下一步的研究计划是将高耐寒性性状与提高产量和改善籽粒品质相结合，使新的冬小麦品种对小麦种植者更具吸引力。籽粒大小是籽粒产量的一个重要组成部分，籽粒大小主要受植物源库关系、决定籽粒发育早期阶段的遗传因素和环境的影响。近年来的研究表明，小麦种子周围的母体组织决定了种子的生长和大小。为了制定增加种子大小的策略，我们将分析不同种子大小的冬小麦群体（bbb800重组自交系，RIL）的早期种子发育，并将其与通过测序进行基因分型获得的基因型数据相结合，以开发遗传图谱。遗传图谱将用于鉴定基因组区域，表征候选基因，分析与早期种子发育相关的遗传因素和调控网络。这些基础知识将用于开发遗传标记，以供小麦育种者在基因组学辅助选择中使用，将决定种子大小和籽粒品质的最佳等位基因组合到耐寒冬小麦品系中，以提高产量和改善籽粒品质。***该项目的成功完成将鉴定出种子大小和品质均有所改善的耐寒小麦品系，以供品种开发使用。具有高耐寒性、大种子尺寸/产量和高种子质量的冬小麦是粮食安全的需要，也是加拿大生产者在国际小麦市场上保持竞争力的需要。**

The high anthropogenic activities during the last century has elevated the atmospheric carbon dioxide levels, increased air temperatures and altered the precipitation patterns around the globe; these climate changes present serious challenges to crop productivity. To maintain food and nutritional security, worldwide increase in crop yield and improved nutritional quality is needed. For Canada, the required improvements include wheat (Triticum aestivum L.), which is a staple in the human diet and an important export commodity for Canadian producers. ***Canada is a major wheat producer and exporter with average annual production of ~30 million metric tons over the last five years and accounts for $5 billion dollar in export revenue. In Canada, the three Prairie Provinces account for 84% of the arable land and primary producers of wheat. Spring wheat (~83%) is the dominant type grown in Canada. However, in years with low winter kill, fall seeded winter wheat produces 20 40% higher yield than spring wheat. Winter wheat is also a very environmentally friendly crop as it efficiently uses spring moisture, matures early and yields more than spring wheat. During the last decade of research, using genomic selection, we have characterized wheat genotypes with increased cold tolerance and improved winter survival compared to the most hardy winter wheat cultivar Norstar. The next step in our research program is to combine the high winter hardiness trait with increased yields and improved grain quality to make new winter wheat cultivars more attractive for wheat growers. An important component of grain yield is seed size that is mainly affected by the plant's source-sink relationship, genetic factors determining the early stages of seed development and environment. Recent studies show that the maternal tissues surrounding the growing seed set the limit to seed growth and size in wheat. To develop strategies to increase seed size, we will analyze early seed development in a winter wheat population (>800 recombinant inbred lines, RIL) varying in seed size and combine it with genotypic data obtained by genotyping by sequencing to develop genetic maps. The genetic maps will be used to identify the genomic regions, characterize the candidate genes to analyze the genetic factors and regulatory networks associated with early seed development. The basic knowledge will be used to develop genetic markers for use by wheat breeders in genomics assisted selection to combine optimal alleles for seed size and grain quality into cold hardy winter wheat lines to increase yield and improve their grain quality. ***Successful completion of the project will result in identification of winter-hardy wheat lines with improved seed size and quality for cultivar development. Winter wheat with high winter hardiness, large seed size/yield and improved seed quality are needed for food security and for the Canadian producers to stay competitive on the international wheat market. **