Isolation and characterization of microsatellite markers in the nuclear genome of the brown alga Laminaria digitata (Phaeophyceae)

Kelps (order Laminariales, Phaeophyta) are the most abundant algae in the subtidal euphotic zone of rocky coasts, from temperate to polar seas. Laminariales present a haplodiplophasic, heteromorphic cycle, in which macroscopic sporophytes alternate with microscopic gametophytes. Not only are they important ecologically, but they are also a main marine crop, cultivated in Eastern Asia and harvested from natural populations in Europe and North and South America. Yet only a few genetic studies have been carried out on Laminariales, mainly because of technical problems. In particular, no information is available on either their reproductive system or on the gene flow between populations. Development of single-locus, codominant, genetic markers in Laminaria digitata therefore represents a particularly useful challenge. We describe here the first set of such markers in brown algae.