果实重量是决定番茄产量的重要因素。因此，克隆果实重量关键基因、并分析其单元型的遗传及互作效应，对于番茄丰产育种具有重要指导意义。番茄果实重量受多个遗传位点控制。目前，已经被图位克隆的主效基因比较少，它们之间的互作效应也知之不多。本课题组最近发现了一个显性主效QTL fw9.1。它可使果实重量增加24.2%，d/a值可达1.76。它已被定位在9号染色体236-Kb的区段内。本项目拟在此基础上，对FW9.1基因进行图位克隆及转基因功能互补验证；利用番茄变异组360份番茄材料分析FW9.1基因的单元型及其遗传效应；利用同一大果番茄材料为轮回亲本的高代回交系，分析FW9.1和已知番茄果实重量主效基因单元型的遗传及互作效应；分析普通番茄中FW9.1和已知番茄果实重量主效基因的优异单元型的分布及组合情况；开发功能型分子标记、找出优异单元型组合。研究结果将为番茄丰产育种提供重要基因资源和有力理论指导。

Fruit weight is an important component of tomato yield. Map-based cloning of the key genes for fruit weight, analysis of their genetic and interaction effects, have important practical significance for tomato high yield breeding. Tomato fruit weight is controlled by many loci. Till now, just a few gene for fruit weight has been cloned and little is known about their interaction effects. Recently, the applicant identified the fruit weight 9.1 (fw9.1), a major dominant quantitative trait locus (QTL) controlling fruit weight in tomato, through QTL-seq. fw9.1 could increase fruit weight by up to 24.2%. fw9.1 also could account for 1.76 of d/a valule. fw9.1 has been narrowed down to a 236-Kb region on chromosome 9. This project will ⑴ determine FW9.1 gene through map-based cloning and transgenic complementation test; ⑵ Analyze the haplotypes of FW9.1 and their genetic effects on fruit weight in 360 tomato lines. ⑶ Analyze the genetic and interaction effects of the haplotypes of FW9.1 and the known genes on fruit weight under same genetic background. ⑷ Analyze the combinations of haplotypes of FW9.1 and the known genes for fruit weigh in tomato breeding lines. ⑸ Develop molecular markers and identify the excellent combinations of haplotypes for fruit weight improvement in tomato. The findings of this project will provide an important genetic resource and strong theoretical guidance for tomato breeding.