基于大花四照花转录组的SSR分布特征分析及引物开发

Analysis of SSR Distribution Characteristics and Primer Development of Cornus florida Transcriptome

大花四照花是极具开发价值的观赏性植物资源,合理开发和可持续利用其种质资源十分必要。本研究以第二代高通量测序的转录组测序数据为基础,通过MISA软件对大花四照花转录组的SSR位点进行筛选和分析。结果显示,共获得30 401个SSR位点,SSR的分布频率为22.90%,平均每2.88 kb出现一个SSR位点;大花四照花SSR位点的重复类型以单核苷酸重复和二核苷酸重复为主,各占所有位点的45.73%和37.98%;重复基序类型较为丰富,共有196种,其中单核苷酸A/T重复类型的数量最多。SSR的重复次数主要以5~30次为主,长度分布在10~87 bp之间,平均长度为17.39 bp。随机选取48对设计的SSR引物进行PCR检测,共有35对引物能扩增出单一、清晰的条带,有效扩增率为72.92%。大花四照花转录组中SSR位点的数量和种类比较丰富,分布密度较大,初步开发的SSR引物扩增率较好,具有潜在的多态性,可为后期的种质资源开发与保护、遗传连锁图谱的构建及分子标记辅助育种等提供基础。

Cornus florida is a valuable ornamental plant resource, and the rational development and sustainable use of its germplasm resources are necessary. This study used the second generation high-throughput sequencing to sequence the transcriptome, and screened and analyzed the SSR locus of the transcriptome of Cornus florida by MISA software. The results showed that total of 30 401 SSR loci, the occurrence frequency of SSR is 22.90%, the average per SSR loci appear a 2.88 kb;the repeat type of the SSR locus in Cornus florida was dominated by mononucleotide repeats and dinucleotide repeats, each accounting for 45.73% and 37.98% of all loci;the repeat motif type is rich, there are 196 species, of which the number of single nucleotide A/T repeat types is the largest.SSR mainly repetitions of 5~30 times based, length distribution between 10~87 bp, average length 17.39 bp. A total of 48 pairs of designed SSR primers were randomly selected for PCR detection. A total of 35 pairs of primers could amplify a single, clear band, and the effective amplification rate was 72.92%. The number and types of SSR loci in the transcriptome of Cornus florida were abundant and the distribution density was large. The SSR primers developed initially had a good amplification rate and pote ntial polymorphism, which could be used for later genetic diversity analysis. The germplasm resources protection, genetic map construction and molecular markerassisted breeding provide theoretical basis.