玉米个体基因组间存在着大量的PAV（presence/absence variation）结构变异，该结构变异如何作用于杂种优势尚未开展系统性研究。本研究以B73、Mo17、F1和6个IBM个体及其组配的3组杂交组合（构成梯度中亲优势）为试验材料，通过泛基因组分析、芯片分析及基因组PacBio测序策略对8个亲本基因组PAV结构变异进行全面挖掘，结合亲本及杂交种（组合）籽粒产量形成关键期（授粉后0、10、22、30、40天）的表达谱RNA-Seq分析以及籽粒容重杂种优势调查，对亲本基因组PAV数量、PAV携带的有利基因、PAV基因表达调控模式、PAV基因在籽粒产量形成过程的动态表达模式及网络调控模式进行分析。该结果将从基因组及转录组层面揭示PAV结构变异作用于籽粒容重杂种优势分子机制。

The tremendous presence/absence variations (PAV), one of the main forms of genomic structural variation, have been found between any two maize variaties. However, the roles of PAV contributed to heterosis have not been systematically investigated. In this proposal, the material of B73, Mo17, F1, six intermated B73 × Mo17 (IBM) individuals, and the corresponding three cross combinations with different heterotic levels in kernel test weight (KTW) will be used for analysis. First, the genomic PAVs between four parent pairs will be identified comprehensively with pan-genome, genomic chip, and PacBio sequencing strategies. Then, the transcriptome of kernel in key developmental stages (0, 10, 22, 30, and 40 days after pollination) will be sequenced used RNA-seq, and heterosis of corresponding KTW will be calculated. Combined these, the roles of the PAV number between the genome, the favorable genes in PAV, the expression regulation of PAV genes, the dynamic expression patterns of PAV genes in the process of kernel development, and the regulation network of PAV genes affecting KTW heterosis will be investigated. Thus, the proposal is expected to elucidate the underlying mechanism of heterosis affecting by genomic PAV structural variation from the genomic and transcriptomic perspective.