Isolated culture and physiological characteristics of four symbiotic Symbiodiniaceae strains from South China Sea
In recent years,coral bleaching events induced by marine heat waves have occurred frequently,and Symbiodiniaceae,as algal symbionts of coral hosts,has been proved to play an important role in controlling coral environmental tolerance.In order to explore the differences among different species of Symbiodiniaceae and their physiological characteristics,four monoclonal strains of Symbiodiniaceae were isolated and obtained from different cnidaria organisms in the South China Sea,and a series of investigations were conducted on their phylogenetic,morphological and various physiological characteristics.The results exhibited that the four strains of Symbiodiniaceae were Symbiodinium(type A3,HNUA3-1),Breviolum(type B1,HNUB1-1),Cladocopium(type C1,HNUC1-1)and Durusdinium(type D1,HNUD1-1),respectively.Observations by light microscopy and transmission electron microscopy revealed that the four strains had higher similarity in morphological characteristics but there were significant differences in specific growth rates,reflecting the species-specific growth characteristics.The specific growth rate of Breviolum sp.HNUB1-1 was the highest,and the cell density of Breviolum sp.HNUB1-1 was significantly higher than that of the other three strains on the 3rd,5th and 7th day(p<0.05),the specific growth rate of Symbiodinium sp.HNUA3-1 was second highest,the specific growth rate of Cladocopium sp.HNUC1-1 and Durusdinium sp.HNUD1-1 was the lowest,and there was no significant difference in cell density within 7 days of culture.Furthermore,different strains waere also specie-specific in maximum quantum efficiency of Photosystem Ⅱ(Fv/Fm).Under the same conditions,the Fv/Fm of the Durusdinium sp.HNUD1-1 was significantly lower than that of the other three strains,reflecting the photosynthetic and physiological characteristics of its potential heat resistance.This study provided theoretical basis for enriching the resources of Symbiodiniaceae in the South China Sea,and clarifying the differences and characteristics of the Symbiodiniaceae,which can be used to provide basic data support for the conservation and restoration of the coral reef ecosystem in the South China Sea.
NETL
NSTL
万方数据
