中文摘要：

在杂交种中,亲本等位基因的表达将会发生变化,导致杂交种转录组活性不同于亲本.通过比较杂交种与亲本之间的转录组活性差异,鉴定出这些差异的调控因子并建立起其与表型差异的联系,就可能从分子水平上解析杂种优势形成的机理.在水稻杂交种全基因组基因差异表达分析的不同研究中,由于所采用转录组分析平台和实验取材组织器官等的差异,所鉴别出来的差异表达基因及其在杂交种中的表达变化模式各不相同.然而,某些研究也揭示了一些共性的结果,主要体现在水稻杂交种中差异表达基因的生物学功能在光合作用、碳水化合物代谢和能量代谢途径中富集.对于导致水稻杂交种转录组活性变化的原因,可以从基于基因启动子区顺式调控元件和与其相结合的反式作用因子的遗传调控机制,以及从基于DNA甲基化、组蛋白修饰和小RNA的表观遗传调控机制两方面来进行解释.今后在水稻杂交种转录组活性变化的分析中,需要针对特定的生物学性状来进行,并提高基因差异表达分析的精确性和特异性.此外,由于杂种优势是多个数量性状的综合体现,可以将全基因组的基因差异表达分析与杂种优势的QTL（quantitative trait loci,数量性状位点）定位及GWAS（genome-wide association studies,全基因组关联分析）等数量遗传学方法相结合,以对水稻杂种优势分子机理进行深入解析.

英文摘要：

Heterosis, or hybrid vigor, refers to the superior performance of hybrids relative to their parents. Although it has been utilized successfully in agriculture for many years, the genetic basis of heterosis remain largely unclear. The classical explanations of this phenomenon, including dominance, overdominance, and epistasis, ultimately tell us little about the mechanisms driving heterosis at the molecular level. Since heterosis generally manifests in a plurality of observable quantitative traits, it is believed that many genes and/or genetic loci contribute to heterosis. The continued development of genomics and bioinformatics has recently enabled us to conduct whole genome level investigations of gene action in hybrids. The expression of many parental alleles is known to be altered in hybrids, which in turn, changes the transcriptomic activity of hybrids compared to their parents. Consequently, by first comparing the divergences in transcriptomic activity observed between hybrids and their parents, and then determining the connection between this differential gene expression and the altered phenotypes observed in hybrids, it is possible to ascertain the mechanisms driving heterosis at the molecular level. Rice has long been one of the most important crops worldwide. Heterosis in rice has been successfully utilized as a strategy for increasing both the yield and quality of this essential crop for several decades. In recent years, many studies have explored the genomic basis of heterosis in hybrid rice. To date, however, many of these genome-wide analyses of differential gene expression have exhibited a number of inconsistencies in their identification of both differentially expressed genes and patterns of gene expression. These discrepancies may stem from the different hybrid combinations, distinct tissues, and variety of genomic platforms utilized in these studies. Some studies do suggest, however, that the genes differentially expressed in rice hybrids may enhance photosynthesis, carbohydrate metabolism, energ