Cytological Observations And Systematics Of Bangiaceae Based On RbcL, NrSSU Gene Sequences

The Bangiaceae includes Bangia and Porphyra which are the most highly valuedseaweed crop in the world. The present study was initiated to observe cytologicalcharacters and analyse the DNA sequences of rbcL and nrSSU genes, to explorephylogenetic relationships of Bangiaceae from various coastal and inland areas ofChina.Bangia sp. were collected from LD, WH, QH, QS, QJ, LYG, RD, QD, PT, PTC andST, including eleven marine samples and one freshwater sample from YQ. Findingsshowed that all the Bangia sp. had the consistent four chromosomes. The marinesamples could be divided into two groups according to the reproduction modes. Someof them had both asexual and sexual reproduction, and the others only reproducedasexually. The freshwater sample of YQ only had asexual reproduction in the whole lifehistory. The DNA analyses show ed the relationship among marine samples was close,but also diverse in the phylogenetic analysis. The YQ sample had much lowerhomology values than the marine samples, but clustered closely with freshwatersamples from other places in the world. These results indicated freshwater samples weregreatly distinct from marine ones.Natural pop ulations of Porphyra from QD, FJ and GD were investigated in thisstudy. The results showed that there existed P. yezoensis, P. suborbiculata in QD,P.haitanensis and P.crispata in FJ, P. haitanensis, P.dentata, P.crispata and P.ramosissima in GD. P. yezoensis had three chromosomes, belonging to the sectionedentata. All the other five species, which were all warm-temperature species, had fivechromosomes with undulated margin. The chromosome of P. ramosissima was firstlyreported within Porphyra sp. In the phylogentic analyses, except P. cripata, Porphyrasp. were clustered together based on the relationships of species. Therefore, thephylogenetic position had a great influe nce on the relationship between differentspecies. According to the15genera of Bangiaceae in the newly revised internationalclassification, the marine samples of Baniga were clustered in “Bangia”1and “Bangia”2, the freshwater sample was clustered in Bangia. And all Porphyra were clusteredwithin Pyropia.