紫茉莉品系观赏性状与遗传多样性的AFLP分析

Ornamental characters and genetic diversity analysis of four o'clock flower strains with AFLP markers

【目的】紫茉莉(Mirabilis jalapaLinn)是中国传统乡土花卉,研究不同种质的观赏性状,对利用这些资源进行杂交育种筛选后代、提高育种的针对性和加快育种进程具有重要的意义。【方法】本研究对具代表性的9个紫茉莉品系进行了株高、花型、花色、童期等观赏性状的比较,并利用扩增片段长度多态性(amplified fragment length polymorphism,AFLP)分子标记技术进行分析。【结果】紫茉莉的观赏性状主要包括株高、花型、花色、童期等,传统分类法可分为高株系统和矮株系统,花型为重瓣和单瓣,其花色有白色、粉色共9种颜色,多样性丰富。通过AFLP技术,采用8对引物组合共扩增出2 569条谱带,其中多态性条带2 488条,多态性条带比率为96.85%,平均每对引物扩增出321个位点,311个多态性位点。9个品系的相似性系数在0.2357~0.6493之问,平均值为0.4425,每个位点的有效等位基因数为1.2044,平均多样性指数为0.2127,遗传相似性系数最高的是5号和8号,达到0.6493,最低的是3和7,为0.2357。【结论】根据遗传相似性系数进行聚类分析,可将紫茉莉品系分为矮株型Ⅰ类和高株型II类,分子聚类结果与表型性状特征分类结果较为一致,而在每一类中具体的观赏性状聚类存在一定差异。通过形态性状与分子标记为紫茉莉品系的研究,为进一步育种利用提供参考。

【Objective】Four o'clock flower(Mirabilis jalapaLinn)is a traditional domestically grown product.Research on various ornamental characters is very important for F1 hybrid selection,and narrowing on breeding target,expediting the breeding process【Method】The ornamental characters of 9strains of four o'clock flower were compared and biodiversity of 9strains were analyzed in this experiment.【Result】The results showed tha the main ornamental characters of four o'clock included plant height,doubleness of flower,color of flower and the iuvenile period etc.The four o'colock flower can be categorized as tall and dwarf type.Single or mutli-flower petal,and colors of flower,such as white,pink,yellow and purple.The 2569 bands were detected by 8elective primer pairs by AFLP,2488bands(96.85%)were polymorphic.On average,each primer combination amplified 321 loci and 311 polymorphic loci.Genetic similarity of 9strains of four o'clock flowers ranged from 0.2357 to 0.6493 with an average of 0.4425.The number of effective alleles for each locus was 1.2044,and the average index of genetic diversity was 0.2127.The highest genetic similarity(0.6493)was found between sample#5and#8,and the lowest(0.2357)was found between sample#3and #7.Cluster analysis showed that 9strains of four o'clock flower can be categorized as tall type II and dwarf type I,which is similar to the two groups of the seedling height characters.The results of morphological characters and AFLP markers demonstrated some important information for further breeding program.