杨梅童期和果实品质性状的遗传与基因组学分析

杨梅是我国南方特色果树，目前栽培地方品种来源于自然实生选种，产业发展需要多方面性状更为优良的新品种。现代杂交育种工作刚刚起步，因此，首先需要解决果树童期和果实品质遗传问题。在杨梅基因组测序工作完成以及雌雄性别遗传控制模式基本明确的基础上，本项目用‘荸荠’x‘东魁’杨梅杂交后代，研究童期，分枝成花特性、花期，花颜色以及果实经济性状（果实成熟期、大小、形状、单果重、硬度、色泽、可溶性固形物、滴定酸含量）的分离规律。通过对‘荸荠’和‘东魁’双亲和杂交后代进行重测序基因型分析，构建高密度分子标记连锁图谱和单倍型区块。应用遗传图谱分析软件，进行简单质量性状的连锁图谱和数量性状的QTL定位分析。根据性状图谱定位结果，在基因组序列区域进行基因扫描，发现候选功能基因成员。找到一些与开花结果性状密切相关的功能基因和优良位点组合。获得童期短、综合经济性状优良的新品系。为现代杨梅遗传育种奠定理论和选择技术基础。

Chinese red bayberry (Myrica rubra, or Myrica rubra) is a special subtropical fruit tree widely distributed in southern China. The existing cultivars are all from natural seedling selections, which could not meet the industry requirement of multiple super elite traits. Currently the artificial controlled crossing project has just begun. After the release of red bayberry genome sequences and sex determining mode and markers development, understanding the genetic and genomic control of juvenile period and fruit quality traits of red bayberry are on the priority list. This research will use a crossing progeny ‘Biqi’ x ‘Dongkui’ to study the segregation of juvenile period, branching habit, flowering and fruit ripening dates, and basic fruit quality traits, such as fruit weight, color, texture, TSC, acidity. Genotyping by sequencing of two parents and off-springs will be used in updating high density marker and haploblock map, and then used in qualitative linkage mapping and QTL mapping. Scanning the genomic region linked to a trait in the reference red bayberry genome will find the key candidate functional genes and elite alleles. We will obtain some good selections with short juvenile period and good horticultural traits for further application in cultivar development and breeding material. This research will provide fundamental basis for modern bayberry cross breeding and selection in Chinese red bayberry.