菊花心江蓠的光合特性及其应用研究

Photosynthesis characteristics of Gracilaria lichevoides and application to culture and bioremediation

测定不同光强下菊花心江蓠(Gracilaria lichevoides)的产氧率和耗氧率.结果表明,20 000 lx以内菊花心江蓠的产氧率和光强的相关曲线的回归方程为y=0. 000 144 3x-0. 122 1,R2=0. 993 8,实验条件下菊花心江蓠的耗氧率为0. 121±0. 010 mg/(g·h),光补偿点为825 lx,光饱和点在20 000～22 000 lx之间,光饱和时的产氧率为2. 723±0. 329 mg/(g·h).光饱和以后菊花心江蓠的产氧率基本保持不变,45 000 lx以后出现轻微光抑制现象.测量水下光强随水深变化情况,发现水深达到水体透明度深度时,光强约14 000～15 000 lx,与菊花心江蓠的最大生长率的光强接近.测量不同养殖模式的溶解氧浓度昼夜变化,发现养殖密度过大可能在凌晨出现缺氧状态.根据菊花心江蓠的光合特性,提出江蓠养殖、江蓠用于生态修复的水深调控方法以及江蓠用于生态养殖的密度调控方法,以保持不同需求条件下较高的经济或生态效益.

The effects of light intensity on oxygen production and consumption rates of Gracilaria lichevoides were studied by“light-dark bottle”oxygen method in indoor and outdoor experiments.The results indicate that under 20 000 lx the rate of oxygen production by G.lichevoides and the light intensity showed linear relationship by correlated equation of y=0.000 144 3 x-0.122 1(R 2=0.993 8).The oxygen consumption rate of G.lichevoides was 0.121±0.010 mg/(g·h),the light compensation point was 825 lx,the saturation point was between 20 000 and 22 000 lx and the oxygen production rate at light saturation point was 2.723±0.329 mg/(g·h).The oxygen production rate was basically unchanged when light intensity was above light saturation point,but it decreased slightly and showed a slight photo-inhibition above 45 000 lx.The light intensity,measured with the changes of water depth,showed that it was 14 000-15 000 lx when the water depth was less than the Secchi depth,and under this light intensity,the growth rate of G.lichevoides reached the highest.It was found that exorbitant breeding density could occur aquatic hypoxia early in the morning by measuring diurnal variation of dissolved oxygen concentration in different cultivation mode.According to the photosynthesis characteristics of G.lichevoides,methods by adjusting the depth of the water for G.lichevoides cultivation or bioremediation,and controlling breeding density for ecological aquaculture were proposed to maintain high economic and ecological benefits for the request of different conditions.