Development of retrotransposon-based SSAP molecular marker system for study of genetic diversity in sea holly (Eryngium maritimum L.)

摘要

Eryngium maritimum L. is a wild plant species threatened or endangered in most of Northern Europe, where species is on the northern margin of its distribution range. Recent studies have found reduction of size and even extinction of many populations. Assessment of genetic diversity in natural populations of endangered wild plant species can reflect condition and fitness of particular population and inform decisions on appropriate conservation measures. Application of inter simple sequence repeat markers and chloroplast DNA sequencing could not resolve genetic relationship between E. maritimum populations in Northern Europe. Therefore, the more sensitive retrotransposon-sequence-specific amplification polymorphism (SSAP) molecular marker system was developed. Six Ty1-copia long terminal repeat retrotransposons were isolated from E. maritimum genome (Tem1-Tem6) and assessed for their utility as molecular markers in this species. Two retrotransposons - Tem2 and Tem5 - were recognized as most informative based on the level of polymorphism and SSAP banding pattern quality. On average, 20.4% of SSAP bands were polymorphic for the five most informative primer combinations in a set of 150 Northern European E. maritimum plants from 13 locations, providing a useful tool for assessment of genetic diversity in this endangered species.