球形棕囊藻生长的营养需求研究

NUTRITIONAL REQUIREMENTS FOR THE GROWTH OF PHAEOCYSTIS GLOBOSA SCHERFFEL

以球形棕囊藻(Phaeocystis globosaScherffel)香港株(Hongkong strain,HK)和汕头株(Shantou strain,ST)为材料,采用正交实验方法研究了氮、磷、铁、微量元素及维生素等营养因子对其生长的影响。磷是球形棕囊藻香港株和汕头株生长的首要限制因子,在添加磷的培养基中,球形棕囊藻生长较快,在无磷培养液中,藻细胞生长较慢,其死亡速率超过生长速率,一般不形成正常生长曲线。汕头株的比生长速率极差值远高于香港株,表明汕头株棕囊藻的生长对营养盐更为敏感。磷酸盐对球形棕囊藻生长的影响极为显著(p<0.01),硝酸盐的影响达到显著水平(p<0.05),而铁、微量元素及维生素对球形棕囊藻生长影响不显著,表明自然海水中铁、微量元素及维生素的含量对球形棕囊藻的生长不构成限制。各因素影响的主次次序为P>N>微量元素>铁>维生素。本研究结果提示,海水富营养化是我国南海海域球形棕囊藻赤潮发生的关键诱因之一。

Effects of N, P, Fe, microelements and vitamins on the growth of two strains （Hong Kong strain and Shantou strain） of Phaeocystis globasa Scherffel were investigated in the present study. N, P, Fe, microelements and vitamins were supplemented to the media at various combinations and concentrations according to orthogonal designed scheme. Results indicated that microelement P was a crucial element for the growth of both HK and ST strains. P. globosa cells grow faster in the medium with supplementary P. In the medium without P,growth curve can＇t be observed. The range of specific growth rate for ST strain was much higher than that of HK strain, which indicated that ST strain was more sensitive than HK strain to nutrients. Statistical analysis indicated that specific growth rate of P. globosa were significant at the level of p 〈 0.01 and p 〈 0.05 when growing at different P and N concentrations respectively. Fe, microelements and vitamins had no remarkable effects on the growth of both strains, which suggested that the natural sea water has plenty of Fe, microelements and vitamins for the growth of P. globosa. The order of nutritional impacting factors was as follow： P 〉 N 〉 microelements 〉 Fe 〉 vitamin. Our results imply that eutrophication of coastal water is one of the critical factors for triggering P. globosa bloom in the South China Sea.