Early development, life history and ecological habits of Grateloupia constricata Li et Ding

As the largest genus of Halymeniaceae, Grateloupia has been widely reported. Here, we observed the life history and early development of Grateloupia constricata Li et Ding and investigated the effects of temperature, irradiance, and photoperiod on the discoid crust and sporeling development of G. constricata under laboratory conditions. We observed that the type of carpospore development was “mediate discal type”. The life history included homotypic gametophyte (haploid), carposporophyte (diploid), and tetrasporophyte (diploid), with typical isomorphic alternation of generations. The results of double factorial analysis showed that both single factorial effects and interaction among temperature, photoperiod, and irradiance were obviously significant on the discoid crust and sporeling development. Furthermore, we found that the optimum combination of condition for the early growth and development of G. constricata was temperature 20°C, irradiance 80 μmol photons/(m2·s) and photoperiod 16L:8D. This study provides the theoretical basis and technical support for the conservation of the Grateloupia germplasm, artificial breeding, large-scale cultivation and sustainable development.