单 位：
中国水产科学研究院东海水产研究所农业部东海与远洋渔业资源开发利用重点实验室;华东师范大学河口海岸国家重点实验室
摘 要：
为了阐明营养盐水平下对东海原甲藻(Prorocentrum donghaiense)和米氏凯伦藻(Karenia mikimotoi)的生长特性,研究了不同营养盐总体浓度和磷限制对两种藻类生长的影响。结果表明,不同营养盐水平对东海原甲藻和米氏凯伦藻的生长影响显著,培养中期添加营养盐(二次添加)可以显著提高两种藻类的细胞浓度,同步测定氮磷营养盐水平发现,一次性添加营养盐培养时东海原甲藻对硝酸盐和磷酸盐吸收利用率分别为31.6%和76.9%,米氏凯伦藻对硝酸盐和磷酸盐的吸收利用率分别为92.5%和99.9%,二次添加营养盐培养时则稍低,同时两种藻类在实验后期较低磷酸盐水平的情况下仍然能维持较高细胞浓度,说明藻细胞内存在明显的营养盐库。在磷限制情况下,东海原甲藻和米氏凯伦藻的生长均受到明显的抑制,东海原甲藻细胞体积在磷限制培养下变化不大,而且米氏凯伦藻细胞体积在磷限制培养一段时间后明显增大,当磷酸盐恢复正常水平,细胞体积又快速恢复。该结果对于阐释不同营养盐水平下东海原甲藻和米氏凯伦藻的生长竞争机制具有一定的启示作用。
译 名：
Effects of different nutrients levels on the growth of Prorocentrum donghaiense and Karenia mikimotoi
作 者：
SHEN Ang-lv;LI Dao-ji;Key Laboratory of East China Sea & Oceanic Fishery Resources Exploitation and Utilization,Ministry of Agriculture,East China Sea Fisheries Research Institute;State Key Laboratory of Estuarine and Coastal Research,East China Normal University;
关键词：
Prorocentrum donghaiense;;Karenia mikimotoi;;nutrient;;growth
摘 要：
Harmful algal blooms( HABs) is an increasingly serious marine environmental problem for aquaculture,fisheries and public health in many coastal areas throughout the world. HABs has become common in the Yangtze Estuary and East China Sea( ECS) since 1980 s. Prorocentrum donghaiense and Karenia mikimotoi have been major harmful bloom species in HAB areas of the East China Sea( ECS) in recent years. Nutrients are important environmental factors related to microalgae growth,and can affect the population dynamics of individual species and species succession in the field. To understand the growth characteristics of P. donghaiense and K. mikimotoi,the effects of different nutrients levels and phosphorus limitation on the growth were examined. In the present study,P. donghaiense and K. mikimotoi were cultured under two nutrient concentrations( f /2 medium added once and f /2 medium added twice) and two phosphate concentrations( f /2 medium and f /2 medium without NaH_2PO_4·H_2O). In addition,the length and width of P. donghaiense and K. mikimotoi were measured by the microscope on 0,9,18 d and 24 d in phosphorus limitation groups,and after recovery culture for 6 d( added NaH_2PO_4·H_2O with f /2 medium level). In the two nutrient concentrations culture experiment,the results showed that the growth of two species were significantly different by different nutrient levels( P < 0. 05),and cell densities in high nutrient level group were higher than that in low nutrient level group,the specific growth( μ) of P. donghaiense in two nutrient level groups were 0. 068 d~(-1)and 0. 034 d~(-1)( from 12 d to 33 d),and the specific growth( μ) of K.mikimotoi were 0. 108 d~(-1)and 0. 069 d~(-1),respectively. In addition,Prorocentrum donghaiense has high absorption efficiency of phosphate( 76. 9%) and K. mikimotoi has high absorption efficiency of both phosphate( 99. 9%) and nitrate( 92. 5%) when determination of the nutrients is done synchronously.Furthermore,two species could survive with a high cell concentration for a long time in the low phosphorus condition,indicating that there are nutrient database in the two species. In the two phosphate concentrations culture experiments,results showed that the growth of P. donghaiense was surpressed remarkably( P <0. 05) in phosphorus limiting conditions on 6 d,and the cell density was always at a very low level( < 10000 cell· m L~(-1)) in the last 10 d; there was no significant difference in the volume of P. donghaiense between two phosphate concentration cultures. The growth of K. mikimotoi was surpressed remarkably( P <0. 05) in phosphorus limiting conditions on 9 d,but the cell density was always at 20 000 cell·m L~(-1)from 9d to 18 d; the cell volume of K. mikimotoi was larger than the control from 9 d to 24 d( P < 0. 05),and the cell volume restored to the normal level when the phosphorus concentration returned to f /2 medium levels.The results in the present study could be used to understand the growth competition mechanism of P.donghaiense and K. mikimotoi in different nutrient levels.
