小麦为群体作物，在产量三要素协调下，适度降低旗叶大小，有利于扩大群体和提高光合效率，是单产进一步提高的突破口。可是现有的小旗叶亲本资源相对较少，有关分子调控机制的研究还鲜见报道。冰草属植物经过长期进化，具有小旗叶典型特性。前期观察表明将冰草1P染色体导入小麦中具有显著降低受体小麦旗叶长、宽的典型表型。本研究以济麦22为轮回亲本，分别将冰草1P染色体整臂、长臂和短臂导入小麦中，创制出BC5代以上的近等基因系材料，探讨冰草1P染色体调控小麦旗叶变小的遗传效应与育种价值。通过转录组和染色质免疫共沉淀测序技术阐明冰草1P染色体调控小麦旗叶变小的分子机制。挖掘冰草1P染色体特异表达基因，对候选冰草特异基因筛选BAC文库，并进行互作蛋白质筛选和在小麦中的转基因过量表达研究，最终提出冰草1P染色体调控小麦旗叶变小的分子模型和基因组互作机制。本研究为利用冰草1P染色体创制小旗叶小麦新种质提供理论指导。

Common wheat as a population crop, can be improved its yield potential by moderately reducing the size of flag leaf, which can increase the spike numbers of population and improve photosynthetic efficiency. However, the available wheat genetic resources with small flag leaf phenotype are rare and the molecular mechanism controlling the size of flag leaf in wheat is still unclear. The wild relative, Agropyron cristatum, carries the small flag leaf elite gene for wheat improvement. The previous observations proved that introducing alien chromosome 1P from A. cristatum into common wheat can reduce significantly the length and width of flag leaf. In this study, we produce the near isogenic lines by backcrossing the addition line into recurrent parent Jimai22 with or without chromosome 1P, 1PS and 1PL, respectively. The objective of this study is uncovering the molecular mechanism of A. cristatum chromosome 1P reducing the flag leaf size in wheat. By applying the RNA-seq and ChIP-seq technologies, we will analyze the expression pattern of introducing alien chromosome 1P into wheat and the genome interaction model between A. cristatum chromosome 1P and wheat chromosomes. Alien genes from A. cristatum chromosome 1P will be identified by SNP-calling method based on RNA-seq reads. The yeast two-hybrid assay will isolate the interaction protein of candidate genes from A. cristatum. The overexpression of candidate genes from A. cristatum chromosome 1P in common wheat will validate the gene function of controlling the flag leaf size. As a result, the molecular regulation model will be created for explaining the nature of phenotype establishment and the genome interaction. Taken together, this study has significant theoretical guidance value towards producing the new germplasms with small size of flag leaf by wide crosses.