RESEARCH ON THE REVISION OF GRATELOUPIA FASTIGIATA LI ET DING (RHODOPHYTA, HALYMENIACEAE) BASED ON MORPHOLOGICAL OBSERVATIONS AND RBCL SEQUENCE ANALYSES

By combining morphological observation with molecular analysis, Grateloupia fastigiata Li et Ding was re-examined. The results showed that:① thallus was dark purplish red, 9-26 cm high, percurrent axes terete basally, dichotomously branched once or twice, cortex sections were 85-160 m thick consisting of 8-11 layers of cells; the auxi-liary cell ampullae exhibited typical Grateloupia-type, carpogonial branch ampullae consisted of six cells, auxiliary cell ampullae consisted of five cells (6cpb-5auxb type), identical with G. asiatica Kawaguchi et Wang. ② According to the phylogenetic tree constructed by gene (rbcL) sequences, there was no sequence divergence between the ten samples of G. fastigiata examined in this research and G. asiatica from Qingdao, which formed a single monophyletic subclade within the large Grateloupia clade of Halymeniaceae, the rbcL sequences differences between it and G. asiatica from Dalian was 1 bp (0.08%), the rbcL sequences differences between it and G. asiatica from Japan and South Korea was 2 bp (0.16%) and 3 bp (0.24%), belonging to intraspecific difference, the rbcL sequences differences between it and other species within the Grateloupia clade I was 18 (1.47%)-76 bp (6.19%), belonging to interspecific difference. Through morphological observations and molecular analysis, G. fastigiata and G. asiatica proved to be the same species, with G. fastigiata as the synonym of G. asiatica.