草莓属植物倍性水平多样，存在种间和倍性杂交障碍。植物的生殖隔离与基因组表观印记机制密切相关，鉴定草莓的印记基因及其调控sRNA分子，可为草莓种间杂交及倍性杂交障碍机制提供表观遗传学基础。以栽培草莓两个基因型为试材进行正反杂交，对胚乳RNA-seq与sRNA-seq进行高通量测序，按照明显偏离2M:1P的标准，筛选出候选印记基因及其调控sRNAs，利用等位基因特异PCR对印记基因与sRNAs进行验证，鉴定出印记基因及其调控的sRNAs，再利用目标区域捕获甲基化测序对印记基因及其侧翼区域的DNA甲基化状态进行分析，明确sRNAs、DNA甲基化共同调控胚乳印记基因表达的作用机制；利用CRISPR/Cas9构建2x绿色草莓部分印记基因及sRNAs突变体，通过与8x栽培草莓种间倍性杂交，确定部分印记基因和sRNAs在杂交障碍中的功能并构建其调控机制模型。

The ploidy levels of genus Fragaria are diverse, interspecific and interploidy hybridization barriers occur generally in the genus. Genomic imprinting is an inheritance process independent of the classical Mendelian inheritance. Sexual reproductive isolation in flowering plants is closely related to the genomic imprinting mechanism. This research will aim to identify the imprinted genes and their regulatory small RNA (sRNA) molecules in strawberry for providing a basis of epigenetics in interspecific and interploidy hybridization barriers of Fragaria spp. First, RNA-seq and sRNA-seq high-throughput sequencing are used to screen the candidate imprinting genes and regulatory sRNA in endosperm of reciprocal cross of two octoploid Fragaria ×ananassa genotypes, based on differently expressed level as the 2:1 ratio of maternal to paternal genomes, then some imprinting genes and regulatory sRNAs will be validated by allele-specific PCR. Second, the methylation states of imprinting genes and their flanking regions are analyzed by targeted regions methylation sequencing to verify how sRNAs and DNA methylation regulate the expression of imprinting genes in endosperm together. Third, the function of imprinting genes and sRNAs in overcoming the interspecific/interploidy hybridization barrier will be analyzed using the diploid Fragaria viridis knock-out mutants, are created using CRISPR/Cas9 gene-editing technology, reciprocally hybriding with Fragaria ×ananassa, then interaction models of some imprinting genes and sRNAs in cross barrier will be constructed.