【摘要】 由转录组测序信息获得的EST-SSR标记具有通用性好、保守性高、多态性丰富、共显性遗传等优点,广泛应用于植物种质资源的遗传多样性分析。本研究通过对不结球白菜(Brassica rapa ssp. chinensis)转录组高通量测序,挖掘SSR位点和开发EST-SSR标记,并进行引物的初步验证及其多态性分析。在不结球白菜转录组的48 817条Unigene序列中共搜寻到17 009个SSR位点,发生频率为18.44%,SSR分布频率为34.84%。不结球白菜SSR位点共包括212种重复基元。其中,单、二和三核苷酸重复为不结球白菜转录组SSR的主要类型,占SSR总量的98.31%。单核苷酸重复最多,占总量的39.70%,其优势重复单元为T/A (26.83%)。利用Primer Premier 3.0设计EST-SSR引物,在批量设计的引物中随机挑选40对进行合成并初步验证,25对引物在92份不结球白菜种质资源中均能扩增出预期大小的条带。其平均等位基因数3.72个,有效等位基因数(effective number of alleles, Ne)、Shannon’s指数(Shannon’s index, I)、多态性信息指数(polymorphism information content, PIC)和基因多样性(gene diversity, GD)分别为2.710 8、0.999 1、0.488 4和0.545 2。所获得的EST-SSR引物可为不结球白菜及芸薹属其他植物的遗传结构分析、种质资源利用及遗传图谱构建提供有效的分子标记。更多还原

【Abstract】 The EST-SSR markers obtained from transcriptome sequencing information have the advantages of good stability, high polymorphism, co-dominant inheritance, and simple operation, and are widely used in genetic diversity analysis of plant germplasm resources. In this study, high-throughput sequencing of the transcriptome of non-heading Chinese cabbage(Brassica rapa ssp. chinensis) was used to seek SSR loci and develop EST-SSR markers, and preliminary primer verification and polymorphism analysis were performed. A total of 17 009 SSR loci were found in the 48 817 unigene sequences of the transcriptional set of non-heading Chinese cabbage, with an occurrence frequency of 18.44% and a SSR distribution frequency of 34.84%. The SSR sites of non-heading Chinese cabbage contained 212 repeat elements whose SSR types were mainly concentrated on single, binary and trinucleotide repeats. Among them, single nucleotide repeats accounted for the most, accounting for 39.70% of the total, and the dominant repeating unit was T/A(26.83%). The ESTSSR primers designed by Primer Premier 3.0 soft were used to randomly selected for 40 pairs in batch design primers for synthesis and preliminary verification. Twenty-five pairs of primers could amplify the expected size bands in 92 non-heading Chinese cabbage germplasm resources. The average number of alleles was 3.72,and the effective number of alleles(Ne), Shannon’s index(I), polymorphism information content(PIC) and gene diversity(GD) were 2.710 8, 0.999 1, 0.488 4 and 0.545 2, respectively. The obtained EST-SSR primers could provide effective molecular markers for genetic structure analysis, germplasm utilization and genetic map construction of non-heading Chinese cabbage and other Brassica plants.更多还原