Generation of expressed sequence tags, development of microsatellite and single nucleotide polymorphism markers in Primula sieboldii E. Morren (Primulaceae) for analysis of genetic diversity in natural and horticultural populations

Primula sieboldii is a self-incompatible ornamental plant that has been cultivated for more than 300 years in Japan. In order to increase the available genomic resources for this species, 5651 expressed sequence tags (ESTs) were generated from seedling and winter bud cDNA libraries. After clustering and assembling ESTs, 2960 unigene elements that contain an homologous sequence to an S locus-linked gene of P. vulgaris were identified. In total, 127 simple sequence repeats (SSRs) were found. The most frequent di- and tri-SSR motifs were GA (78.6%) and ATT (12.9%), respectively. Twenty SSR and 40 single nucleotide polymorphism (SNP) markers were developed. These markers were evaluated for polymorphisms using 24 individuals (Y) from a population in Yatsugatake and 14 individuals (PS) from across the distributional range of P. sieboldii in Japan. The average level of expected heterozygosity within Y and PS was 0.39 and 0.48, respectively for EST-SSR markers and 0.26 and 0.29, respectively for SNP markers. The level of polymorphism for EST-SSR markers was lower than that for genomic SSR markers developed in a previous study. We also surveyed the genetic diversity of 56 cultivars, which had lower allelic richness than the Y and PS populations.