Polymorphisms in different EST-SSR types derived from the Chinese bayberry Myrica rubra, Myricaceae) transcriptome.

Most plant expressed sequence tag-simple sequence repeats (EST-SSRs) are not polymorphic, and it is important to learn the characteristics of highly polymorphic EST-SSRs. In this study, 357 compound and 5557 non-compound EST-SSRs, identified from the transcriptome of the Chinese bayberry (Myrica rubra 'Biqi'), were divided into 11 types based on their characteristics. Polymorphisms in all 11 EST-SSR types were investigated in 10 cultivars. The percentages of polymorphic loci ranged from 12.9 to 87.5%, with 2-ntL having the highest, followed by 3-ntL, Compound B, and Compound A. The number of alleles and the polymorphic information content of 2-ntL and Compound B were the highest, followed by 2-ntM and Compound A. Therefore, we recommend that 2-ntL, Compound B, and Compound A EST-SSRs should be preferentially selected for the screening of polymorphic EST-SSRs in the Chinese bayberry. Our results should facilitate genetic and breeding studies of this species, and provide a reference for similar study in other plant species.