【摘要】 分析云南松转录组中的SSR位点信息的分布及其序列特征,为SSR引物的开发做前期工作.从80 000条转录组Unigene序列中,搜索到2 455个SSR,出现频率为3.07%,分布的平均距离29 kb.SSR以三、二核苷酸占优势,分别占总数42.73%和27.25%,而以四核苷酸的较少,仅占总数的0.98%.重复片段长度12~25 bp,其中近90%的集中在12~20 bp,平均16.09 bp.AT/AT与AGC/CTG和AAG/CTT为二、三核苷酸优势重复基元,分别占基元总数的16.66%、9.65%和8.39%.从2 899对引物中随机挑选32对引物用于检测,24对成功扩增.云南松转录组SSR位点出现的频率较高,分布距离较近,基元类型丰富,重复次数较高,具有较高的多态性潜力.云南松转录组产生的Unigene是开发SSR的有效来源,获得的SSR引物可为云南松种质资源的遗传变异研究提供更多的标记.更多还原

【Abstract】 In total 80 000 Unigenes from needle transcriptome of Pinus yunnanensis Franch. 2455 SSRs identified were screened using MISA software and identified. The frequency of SSR was 3. 07% and mean distribution density was 29 kb. Tri-nucleotide and di-nucleotide were major repeated types,accounting for 42. 73%and 27. 25%,respectively. Tetranucleotide was minimum(0. 98%). AT/AT,AGC/CTG and AAG/CTT were respectively most frequent repeated motifs in di-nucleotide and tri-nucleotide repeated types,and accounting for16. 66%,9. 65% and 8. 39%. SSR primers were designed based on these Unigenes. 24 primers were successfully amplified out of 32 primers which were selected randomly from 2 899 primers. The SSR loci in the P. yunnaensis transcriptome showed moderate frequency of distribution,close distribution distance,rich repeated types,high repeated times and significant potention of polymorphism. The results indicated that the Unigenes obtained from transcriptome sequence in P. yunnanensis can be used as an effective way for the development of SSR loci. The SSR primers will provide more markers for the research of genetic variation of P. yunnanensis.更多还原