CONSTRUCTION AND CHARACTERIZATION OF A TENTATIVE AMPLIFIED FRAGMENT LENGTH POLYMORPHISM-SIMPLE SEQUENCE REPEAT LINKAGE MAP OF LAMINARIA (LAMINARIALES, PHAEOPHYTA)

A tentative amplified fragment length polymorphism-simple sequence repeat (AFLP-SSR) linkage map of Laminaria was constructed using a haploid population of 40 gametophyte clones isolated from an individual of Dongfang No. 2, the first commercially cultured hybrid of a female gametophyte clone of L. japonica Aresch. [=Saccharina japonica (Aresch.) C. E. Lane, C. Mayes et G. W. Saunders] and a male one of L. longissima Miyabe [=Saccharina longissima (Miyabe) C. E. Lane, C. Mayes et G. W. Saunders]. To the map, 263 markers (255 AFLP, seven SSR, and the gametophyte sex) were assigned. The map consisted of 25 linkage groups (LGs) with >= four markers, five triplets, and 15 doublets, which is 1,629.0 centiMorgans (cM) in length, covering 66% of Laminaria genome. The maximum space between loci is 24.63 cM. A putative sex-determining region was identified in LG(2), which was characterized by a dense marker distribution around the gametophyte sex locus. The linkage map itself and the methodology associated with its construction will facilitate the genetic study and further trials of the linkage map construction of Laminaria.