鼠尾藻幼孢子体培育条件探究

为探究鼠尾藻Sargassum thunbergii幼孢子体早期生长发育适宜的培养条件，设置了光照度、温度、盐度3个影响因素3个水平的正交实验，以及氮磷营养盐水平实验。研究表明，温度对鼠尾藻幼孢子体的生长影响最显著（P〈0．05），25℃时幼孢子体比生长速率（sGR）获得最大值，为10．78％，随着温度的降低sGR逐渐降低；盐度对幼孢子体的SGR影响显著（P〈0．05），盐度30时幼孢子体生长较快，盐度降低SGR也降低；光照度2000～8000lx对幼孢子体的生长影响不显著，SOR极差接近误差水平。氮磷营养盐水平对鼠尾藻幼孢子体的生长影响较大，实验用自然海水中氮素基本可以满足幼孢子体的需求，而磷元素相对缺乏。氮素加富条件下，氮磷比大于15：1时不利于幼孢子体的生长，适宜的氮磷比为10：1～2：1。结果表明，温度25℃、盐度30、光照度20001x是鼠尾藻幼孢子体早期生长发育适宜的条件。培养液氮素含量保持在0．45～1mg/L，磷含量保持在0．3mg/L左右有利于幼孢子体快速生长。

Cultural conditions for Sargassum thunbergii germlings

To determine the suitable cultural conditions for the Sargassum thunbergii germlings, orthogonal experiments on three growth and development of factors （illumination, tern perature, and salinity, each with three levels） and the nutrients level experiments were carried out. The results showed that the effect of temperature on the special growth rate （SGR） of S. thunbergii germlings was highly significant （P〈0.05）. The maximum value of SGR of germ lings was 10.78% when the temperature was 25 ℃. The SGR decreased gradually as the tem perature dropped. Effect of salinity on the SGR of germlings was significant （P%0.05）. The germlings grew faster when salinity was 30, whereas the SGR decreased as salinity reduced. Effect of illumination （2 000-8 000 ix） on the SGR was not significant and the range of SGR wasclose to the error. Nitrogen and phosphorus nutrients levels had a great influence on the SGR of S. thunbergii germlings. The nitrogen concentration of the natural seawater in the experiments basically met the requirements of the germlings growth~ however, the phosphorus was relative ly insufficient. When N/P was over 15 ： 1, it was adverse to germlings growth. The suitable N/P ratio was about 10 ： 1-2 ： 1. In conclusion, temperature 25 ℃, salinity 30 and illumination 2 000 lx were the suitable culture conditions for S. thunbergii germlings. Culture medium with nitrogen concentration of 0.45-1 mg/L and phosphorus concentration of 0.3 mg/L was benefi- cial to the germlings growth.