特异四季草莓夏季开花新基因FaPF的精细定位与功能分析

延长熟期是水果育种共同目标。四季草莓夏季开花，周年生产，能填补夏秋草莓鲜果空白，其发展瓶颈是高温导致开花受限。鉴于目前四季草莓夏季开花基因FaPFRU来源于冷凉区野生种弗州草莓且关键基因未知，本项目深入挖掘我国高温区四季草莓夏季开花基因（FaPF）资源。申请人前期研究显示国家草莓种质资源圃有3份非FaPFRU基因来源的特异四季草莓种质，连续9年在南京炎热夏季开花，夏季开花性状为杂合状态下单显性核基因遗传，初定位于第四号染色体一个新区间。本项目拟在初定位区间内开发分子标记，利用南京夏季大棚高温筛选的大群体精细定位；结合生物信息学和表达分析，确定候选基因；构建超表达和CRISPR/Cas9载体，转化草莓，通过高温下表型、表达分析验证基因功能；开发分子标记，应用于草莓高效分子育种。项目前期基础扎实，试材特异，筛选方法独特，结果将为选育适栽区更广的四季草莓提供可能的基因资源和理论依据。

Extending the fruiting season for new strawberry cultivars is a common breeding goal. Perpetual flowering strawberry can flower in summer and produce fresh strawberries in year-round. Control of flowering under hot temperature is one of the key processes that determine growing areas of strawberry. Several independent research groups have all identified a major locus FaPFRU associated with perpetual flowering in multiple bi-parental populations, which is originated from the wild parental species F. virginiana ssp. glauca Wasatch Mountains, but the causal gene is not known. In our previous study, three specific strawberries, which can flower in summer for 9 consecutive years without the FaPFRU allele have been obtained. Genetic analysis indicated that perpetual flowering is controlled by a single dominant nuclear gene in the heterozygous state. A new genomic region, Fvb4-4 6 Mbp, was preliminarily located based on the use of the BSA (Bulked Segregant Analysis)-Seq technique. In this study, a lot of new markers with CAPS, SSR, SNP will be developed in 6 Mbp region to delimit the region from a larger similar to BC1 population from the cross between a specific perpetual flowering strawberry with a seasonal flowering strawberry under extremely high temperature. Based on the bioinformation analysis, together with qRT-PCR expression analysis, Potential candidate gene(s) will be identified. CRISPR/Cas9 and overexpression of FaPF in strawberry will be investigated under high temperature for gene function analysis, related genes will be checked. The marker linked to the FaPF will be developed for improving breeding efficiency. Different from other research, such as specific strawberry germplasm, extremely high temperature and new reference F. x ananassa genome, this study will provide the new gene resource for perpetual flowering strawberry breeding.