利用SNP分子标记分析鉴定不同形态的化橘红(Citrus grandis var.tomentosa)单株

Genetic diversity analysis of different Citrus grandis var.tomentosa samples based on Single Nucleotide Polymorphism Markers

【目的】在对比化橘红不同品种形态特征的基础上,利用SNP(Single nucleotide polymorphism)分子标记分析其遗传差异,以期获得能准确鉴定化橘红不同品种的有效方法。【方法】依据叶片及果实茸毛特征,从不同果园采集9个代表性的化橘红单株,分别对果实及叶片进行测定。采用14个SNP位点,结合高分辨率熔解曲线分型(High resolution melting analysis,HRMA)技术对供试材料进行遗传多样性分析。【结果】同一采样地‘光青’单株8和9,仅叶片宽度存在显著差异,果实及叶片的其他特性差异不明显;同一采样地单株样4(‘正毛’)与样7(‘副毛’)的叶形指数及果形指数差异不显著,但叶片及果实的其他特性差异显著;同一果园不同品种的单株叶片及果实部分特性差异不显著。不同果园的同一品种单株,因栽培条件及管理等方面的差异,叶片及果实的部分特征存在显著差异。采用14个SNP位点可将9个化橘红样本有效区分,平均PIC(Polymorphism information content)值为0.29,所有SNP位点的平均自交系数为-0.09。【结论】仅凭形态特征很难区分化橘红不同品种的单株,而采用14个SNP位点能有效鉴定化橘红不同品种的单株。

[Objective] To reveal morphological characteristics and genetic diversity of different varieties of Chinese herb Huajuhong （Citrus grandis var. tomentosa）, an effective method is needed. [Methods] Based on the characteristics about peel and leaf tomenta of Huajuhong, nine representative varieties were collected from different orchards. The morphological characteristics of leaf and fruit were analyzed by statistical methods with SPSS software. In addition, the genetic diversity of these samples were further analyzed by SNP markers with high resolution melting analysis （HRMA）, the data were analyzed by powermarker 3.25, GeneAlEx 6.5 and DARwin 5. [Results] In the same sampling place, there is a significant difference in leaf width between the samples 8 and 9, the same Huajuhong strain ＇Guangqing＇. However, between the different varieties, there is no significant difference in partial features of both leaf and fruit. These nine samples were divided into eight genotypes by 14 SNP loci, the average PIC value and inbreeding coefficient was 0.29 and -0.09, respectively. [Conclusion] It is difficult to make a distinction between the different varieties just by morphological characteristics, and the SNP marker is a better way to discriminate the different Huajuhong varieties.