The Eco-physiological Studies Of Phosphorus On The Growth Of Prorocentrum Donghaiense

Since the middle 1990's, Prorocentrum donghaiense blooms have frequently been recorded in the adjacent waters of the Changjiang River Estuary. The eco-physiological characters of Prorocentrum donghaiense to phosphorus have been studied at the cellular level in the paper.The absorption chatacter of Prorocentrum donghaiense to phosphate indicated that the K_s of P. donghaiense to DIP is 2.746 μM, a little bit lower than that of Alexandrium catenella (3.771 μM) , but obviously higher than Skeletonema costatum (0.725 μM) . So the competition ability of P. donghaiense to DIP is lower than that of S. costatum. The results also revealed that P. donghaiense could use several DOP— —ATP, G-6-P, G-P, and the nutritional value of ATP and G-6-P was equal to the DIP.The cellular growth kinetics research of P. donghaiense indicated that μ_max of P. donghaiense was 0.625 day^-1, a little bit higher than that of A. catenella (0.501 day^-1), but obviously lower than that of S. costatum (1.855 day^-1) . The μ_max value of P. donghaiense is in the ordinary range of dinoflgellate growth rate. The μ_max and the maximum biomass attained from the long-term starved cells was obviously higher than that of the ordinary cells.The cellular nutrient storage ability research of P. donghaiense showed that the luxury coefficient of nitrogen R_N (41.5 and 42.4) and phosphorus R_P (4.3 and 10.7) of P. donghaiense and A. catenella were higher than those of R_N (2.6 and 6.0) and R_P (2.5 and 1.2 ) of S. costatum and Pseudo-nitzschia pungens. The growth potential of storage nitrogen T_N (5.32 d and 6.81 d) and storage phosphorus T_P (2.08 d and 4.31 d) of P. donghaiense and A. catenella were higher than those of T_N (0.56 d and 1.24 d) and T_P (0.53 d and 0.13 d) of S. costatum and P. pungens, too. The higher nutrient storage ability (R_N和R_P) and growth potential (T_N的T_P) of P. donghaiense result in its A-strategistis, and this is benefit for the formation of long-lasting spring blooms.We can conclud that the higher K s value of P. donghaiense made its weak in absorption of DIP in medium, and the lower μ_max value of P. donghaiense made its...