Development and Application of SSR Markers in Idesia polycarpa Based on SLAF-seq Technology
To develop SSR(simple sequence repeat)markers in Idesia polycarpa Maxim.,we constructed a SLAF-seq(specific locus amplified fragment sequencing)database of I.polycarpa.Based on the polymorphic SLAF-tags,we identified 30 121 SSR loci using MISA software,the occurrence frequency of SSR was 6.16%.And there were 3 451 repeat motif types within the SSR sequences,among which mononucleotide,dinucleotide and trinucleotide were the dominant repeat motifs,the SSR number was 22 191(73.67%),3 184(10.57%)and 1 338(4.44%),respectively.The proportion of A/T motif repeat in mononucleotide type was the highest,a total of 22 117(73.42%)SSR loci were identified.TA/AT(1 743;5.79%)and AA~(A,G,C,T)(233;0.77%)were the highest in dinucleotides and trinucleotides types,and 78.52%SSR had a length from 10 bp to 15 bp.To verify the feasibil-ity of these SSR markers,100 pairs of primers were designed and synthesized randomly,the SSR-PCR results showed that 96 pairs of primers could amplify expected bands,and 35 pairs of primers could amplify polymorphic bands.Furthermore,6 pairs of primers were used to analyze the genetic relationship of 30I.polycarpa samples,the clustering results well reflected the source,geographical distribution and resource characteristics of these samples.Above results confirmed that the SSR markers developed in this study had low cost and high polymorphism,which could be used for germplasm resources analysis,genetic map construction and molecular assisted breeding of I.polycarpa in the future.
Idesia polycarpa Maxim.Simple sequence repeat(SSR)Specific locus amplified fragment sequen-cing(SLAF-seq)