西瓜DUS测试标准品种SSR指纹图谱构建及应用

Construction and Application of SSR Fingerprint Database of the Example Varieties in Watermelon DUS Testing

采用代表最大限度西瓜遗传多样性的SSR核心引物组合,分析了西瓜DUS测试指南中24份西瓜标准品种的遗传多样性与核酸指纹。以基于重测序获得的SNP标记构建的17份西瓜材料的系统发育树为参照,对24份标准品种进行了遗传多样性分析,在遗传相似系数0.80处将24份标准品种分为3大类群,结果表明核酸指纹分类比传统形态学分类更为准确。采用二维(QR)编码构建了西瓜24份标准品种的SSR指纹图谱,并利用本技术以保护品种京欣2号与对照品种京欣1号为例,进行了DUS分子鉴定测试,共扩增32个SSR位点,京欣1号和京欣2号之间有4个位点存在差异,品种间遗传相似系数为0.89,比形态学鉴定的差异位点更多。本研究建立的西瓜DUS标准品种SSR指纹图谱与分子检测技术,可以应用到西瓜品种DUS分子检测实践,同时也为西瓜品种纯度与真实性鉴定及遗传背景分析提供了技术依据。

A core set of SSR markers which represent the maximize watermelon genetic diversity was used to analyze the genetic diversity of 24 example varieties in watermelon DUS testing, then the SSR fingerprint database of these varieties was constructed. Based on the SNP-based dendrogram for the 17 resequencing lines, we evaluated the genetic relationship among these varieties, and they were classified into 3 groups at the similarity coefficient of 0. 80, this marker-based clustering showed more accurate than the traditional morphological clustering. Using two- dimensional （QR） code, the SSR fingerprint database of 24 example varieties was constructed. The utility of this detection system in DUS molecular test was analyzed using a PVP varieties Jingxin No. 2 and its control Jingxin No. 1, there were 4 polymorphic alleles among 32 alleles and their similarity coefficient was 0.89. It showed more polymorphic alleles and more accurate than morphological identification. The SSR fingerprint database of example varieties and molecular detection system used in this study could be applied in DUS molecular test of watermelon. Moreover, they would provide a basis for genetic purity, genetic background screening, and authenticity fast evalua- tion of watermelon.