Isolation, characterisation and cross-species transferability of microsatellite markers for Riella macrocarpa (P.Allorge) Puche et al. (Riellaceae, Sphaerocarpales).

Riella Mont. is unusual among bryophyte genera because its species have an ephemeral habit and grow submerged in fresh or brackish waters. Most species show fragmented distribution areas and have few known populations and are thus of conservation concern. The flagship Mediterranean species R. helicophylla (Bory & Mont.) Mont. has recently been taxonomically reassessed, and most populations have been placed in a new species, R. macrocarpa (P.Allorge) Puche, Segarra-Moragues, Sabovlj., M.Infante & Heras. Here we describe the development of nuclear microsatellite markers for R. macrocarpa with the aim of characterising the population genetic dynamics of this species of conservation concern, and we report their potential use in other species of the genus. Nuclear microsatellite markers were isolated from 454 genomic libraries and amplification parameters optimised for the set of loci finally selected. Nine microsatellite loci were characterised and amplified a total of 53 alleles in a sample of 120 individuals from four populations, having a mean of 5.89 alleles per locus. Unbiased genetic diversity for the polymorphic loci within populations ranged from 0.067 to 0.791. Cross-species transferability assayed in six other species of Riella covering reproductive and taxonomic diversity in the genus showed transferability success rates ranging from 77.8% to 100%, with 33.3% to 57.1% of the successfully transferred loci being polymorphic within species. These markers will be useful for studying population genetic diversity and structure and will contribute towards better conservation management of populations of R. macrocarpa and other species of Riella. [ABSTRACT FROM AUTHOR]