RESEARCH ON THE REVISION OF GRATELOUPIA CONSTRICATA LI ET DING BASED ON MORPHOLOGICAL OBSERVATIONS AND EARLY DEVELOPMENT OF SPORES AND MOLECULAR ANALYSES

Through morphological and early development observation followed by molecular analysis, we re-examined Grateloupia constricata Li et Ding collected from Qingdao, Shandong Province. The results showed that: (1) The thalli were upright, brown-red or purple-red, single or clustered, up to 10—30 cm high fleshy and gelatinous in texture. The first branch was flat with pinnately branched 1—3 orders. The branches were reversed, alternate or partial and usually constricted or tapered at the base. Thallus were composed of cortex and medulla. The cortex had 7—10 cell layers and the medulla was consisted of many rhizoidal filaments, 80—120 microns thick, The medulla is consisted of an irregular arrangement of medullary filament. Carpogonial branch ampullae had six cells, auxiliary cell ampullae had five cells (6cpb-5auxb type). Gametophytes dioecious, mature tetrasporangia originated from inner cortex cells and splited into cross. The above characteristics were similar to those of G. asiatica Kawaguchi et Wang. (2) The early developmental type of G. constricata Li et Ding was ‘mediate discal type’, which is consistent with G. asiatica. (3) Based on the phylogenetic tree constructed by rbcL sequences, there was no sequence divergence between the eight samples of G. constricata and G. asiatica from Qingdao and Dalian, which formed a single monophyletic subclade within the large Grateloupia clade of Halymeniaceae. The rbcL sequences differences between G. constricata and G. asiatica from South Korea and Japan were 2 bp (0.17%) and 3 bp (0.25%), which were intraspecific difference. Based on the phylogenetic tree constructed by gene (COⅠ), there was no sequence divergence between the eight samples of G. constricata and G. asiatica from South Korea, which formed a single monophyletic subclade. Consideringmorphological observations and molecular analysis, G. constricata Li et Ding and G. asiatica Kawaguchi et Wang were proved to be the same species. Accroding to the priority rule, G. constricata Li et Ding was the synonym of G. asiatica.