光照和营养盐胁迫对龙须菜生长及生化组成的影响

以龙须菜(Gracilaria lemaneiformis)为实验材料,分别研究了光照强度、营养盐胁迫对其生长及生化组成的影响。结果表明,在800～3000lx的范围内随光强的升高,龙须菜生长率增加,但藻红素(PE)、叶绿素a、蛋白质和可溶性总糖含量却降低,即低光强更利于龙须菜生化组分的积累。饥饿处理组、饱和处理组及正常对照组的生长率分别为0.9%,5.01%,3.06%。饥饿处理组的总C含量最高,总N及C/N比值高(>15),饱和处理组则相反,C/N比值<10,即存在C高N低、N高C低的现象。表明水体营养状况对龙须菜生长、体内生化组分有显著影响。总C、总N及C/N比都能很好地反映藻体的营养状态。饱和处理组藻体呈现深红色,饥饿处理组藻体色泽为浅黄色,因此也可根据藻体色泽的变化来估计藻体的营养状态。

Effects of light and the stress of nutrients deficiency on the growth and levels of chemical constituents of Gracilaria lemaneiformis

The main effects of light and the stress of nutrients deficiency on the growth and levels of chemical constituents of Gracilaria lemaneiformis were studied indoors. It was found that light intensity was an important factor regulating the levels of chlorophyll-a phycoerythrin(PE), and growth rates. Higher levels of light intensity make higher growth rates but lower levels of chlorophyll-a and phycoerythrin(PE). The special growth rates (RSG) in the group of the starved, the control and the fed were 0.9%, 3.06% 5.01%,respectively. Chemical analysis shows that there were higher levels of total nitrogen (TN) but lower total carbon (TC) of the fed. The relationship of total nitrogen and total carbon was inverse.