SEQUENCE-TAGGED-SITES (STSS) OF CDNA CLONES IN CRYPTOMERIA-JAPONICA AND THEIR EVALUATION AS MOLECULAR MARKERS IN CONIFERS

We have generated 66 sequence-tagged-site (STS) markers from cDNA clon es of Cryptomeria japonica, and 60% of them have already been mapped i nto C. japonica linkage groups. All of the STS markers showed a single fragment following polymerase chain reaction (PCR) amplification. We investigated by polymorphism of these STS markers in a mapped F-2 popu lation and 15 plus trees by means of a restriction endonuclease analys is. Polymorphism levels were 10.6% and 22.7% in the F-2 population and the 15 plus trees, respectively. PCR amplification levels of the 66 S TS markers in 14 conifer species varied depending on their genetic rel ationship with C. japonica. Taxodium, which is closely related to C. j aponica, had the most amplifications (31.82%), followed by Sequoiadend ron giganteum, which is of the same family. The average proportion of PCR amplifications in each family gradually declined in the following order: from Taxodiaceae to Cuppresaceae, Sciadopityaceae, Pinaceae, an d Taxaceae. These results are in general agreement with a molecular ph ylogenetic relationship based on chloroplast DNA. The 66 STS markers w ill be useful as on anchor point for genome mapping and population gen etics, and some of them will also be useful when studying other conife rs.