Effects of Initial Cell Density on Interspecific Growth Interaction Between Isochrysis galbana and Phaeodactylum tricornutum

Effects of initial cell density on interspecific growth interaction between Isochrysis galbana and Phaeodactylum tricornutum is studied through experiment by co-culture method.The results show that the different initial cell densities have apparent effects on the relation of interspecific growth competition between I.galbana and P.tricornutum.At three different inoculative proportions,P.tricornutum always dominates in the competition with I.galbana and exhibits inhibition to the growth of I.galbana.Moreover,with increased amount of inoculums,the interspecific dominance of P.tricornutum and the inhibition on the growth of I.galbana are found to be more significant.Only at the inoculation proportion for I:Q = 4:1,the growth of P.tricornutum is also inhibited by I.galbana even though Heterosigma akashiwo is still in dominance in the competition.