川党参转录组 EST-SSR 位点分析.

【Objective】 The study aimed to explore the SSR locus and distribution characteristics of Codonopsis tangshen Oliv transcriptome. 【Method】 Transcriptome sequencing was performed on C.tangshen leaves. The SSR locus of the transcriptome sequence was identified by MISA software, and functional annotation was performed on the Unigenes containing the SSR locus. Primer 3.0 was used to design EST-SSR primers, and the amplification stability of EST-SSR primers was verified based on C.tangshen germplasm from different regions. 【Result】 A total of 124 179 Unigenes were identified from the transcriptome sequences of C.tangshen, of which 26 084 Unigenes contained 35 827 SSR locus, with a SSR occurrence frequency of 21.01%.There were 165 types of SSR repeat elements in these SSR locus. From the distribution ratio of repeat elements in all the SSRs, the single nucleotide repeat elements A/T accounted for the highest percentage of 37.59%. In respect of the average distance of nucleotide repeat units, pentanucleotide showed the largest distance of 1288.54 kb. Concerning the proportion of primitive repetition times, the SSRs with that of ten accounted for the largest percentage of 21.55% (7722). The base count of SSR sequences was concentrated between 12 and 19 bp, with a total of 19 628 sequences (54.79%). There were 6933 potential polymorphic SSRs above 20 bp, accounting for 19.35% of all.27 SSR primers with stable amplification were selected to amplify the genomic DNA of C.tangshen, with the amplified fragment size ranging from 124 to 393 bp. Based on germplasm resources from different regions of C.tangshen, partial polymorphic markers with clear bands were selected. In addition, 26 084 Unigenes containing SSR locus were annotated by Go and KEGG analysis. These genes were highly enriched in biological processes such as transcriptional regulation, DNA binding, catalysis, and signal transduction. 【Conclusion】 SSR locus of C.tangshen transcriptome have high potential polymorphism, and developed potential polymorphic SSR markers will be used in research on genetic diversity analysis, germplasm identification, molecular assisted breeding, etc. of C.tangshen. [ABSTRACT FROM AUTHOR]