Development of SSR Markers in Aquatic Plant Nymphoides peltata( Menyanthaceae ) Based on Information from Transcriptome Sequencing

Using the program MISA,a total of 12319EST-SSRs were sought out from 79536ESTs of aquatic plant Nymphoides peltata.Dinucleotide and trinucleotide SSRs were the two main motif types,accounting for 57.31% and 30.87%,respectively.The most abundant di-and tri-motifs were AG/CT(29.76%)and AAG/CTT(8.66%),respectively.We randomly selected 130primer pairs to evaluate their application and polymorphism across two populations of N.peltata.Seventyeight SSR markers were amplified successfully,yielding clear and discernible bands,among which37were found to be polymorphic and the polymorphic rate was 47.44%.Using the polymorphic SSR markers,a total of 114alleles were detected.The number of alleles per locus ranged from 2to 6(mean 3.08).Observed heterozygosity(Ho)and expected value(He)per locus varied from 0.229to 1.000and from 0.351to 0.756,respectively.Polymorphism information content(PIC)ranged from 0.286to 0.698,with an average of 0.495.The results indicated that the development of SSR molecular markers from the EST dataset generated by next generation sequencing in the aquatic plant N.peltata is valuable and effective.These newly generated SSR makers will provide new tools for studying genetic diversity and population genetic structure of N. peltata.