Development and characterization of EST‐SSR markers for Vitex negundo var. heterophylla (Lamiaceae)

PREMISE OF THE STUDY: Vitex negundo var. heterophylla (Lamiaceae) is a dominant shrub in the warm temperate zone of northern China. Expressed sequence tag–simple sequence repeat (EST‐SSR) markers were developed to investigate its genetic diversity and structure. METHODS AND RESULTS: We detected 12,075 SSRs in V. negundo var. heterophylla using transcriptome sequencing. Primer pairs for 100 SSR loci were designed and amplified in three populations of V. negundo var. heterophylla. Sixty loci were amplified, of which 14 were polymorphic. The number of alleles per locus ranged from two to 15, and levels of observed and expected heterozygosity ranged from 0.241 to 0.828 and from 0.426 to 0.873, respectively. All primer pairs amplified PCR products from V. rotundifolia but only four of them amplified products from Leonurus japonicus. CONCLUSIONS: The identified EST‐SSR markers will be useful for future molecular and reproductive ecology studies of V. negundo var. heterophylla and V. rotundifolia.