低温胁迫后不同回温速度下吉富品系尼罗罗非鱼昏迷率和死亡率研究

Study of Coma Rate and Mortality of GIFT Tilapia Treated with Different Temperature-increased Speeds after Chilling Stress

应用室内人工降温,以0.2℃/3 h匀速降温至半数致死温度(8.6℃),然后以0.4、0.7和1.0℃/4h升温至室温。对持续时间、累计昏迷率和累计死亡率进行线性回归分析。结果表明:累计昏迷率与持续时间呈显著的线性相关,0.4℃/4 h上升段和下降段试验组线性回归方程分别为:y=-0.982+0.012x和y=0.929-0.005x;0.7℃/4 h上升段和下降段试验组线性回归方程分别为:y=-1.008+0.012x和y=0.789-0.004x;1.0℃/4 h上升段和下降段试验组线性回归方程分别为:y=-0.460+0.006x和y=0.914-0.006x。累计死亡率与持续时间呈显著的线性相关,0.4、0.7和1.0℃/4 h试验组线性回归方程分别为:y=-0.737+0.008x、y=-0.256+0.004x和y=-0.490+0.005x。累计昏迷率与累计死亡率呈显著的线性相关。0.7和1.0℃/4 h组的回温速度可以作为较理想的回温模式,为后续的耐寒选育提供耐寒的罗非鱼亲本。

In the condition of indoor artificial cooling,with 0.2 ℃/3 h cooling down to lethal temperature of 50 ％ （8.6℃）,the temperatue rose at the speeds of 0.4,0.7 and 1.0℃/4h to room temperature.The results showed that cumulative coma rate and duration were in significant linear relationship.The linear regression equations between cumulative coma rate and duration in the rising stage and falling stage were：y=-0.982 ＋0.012x and y =0.929-0.005x,y =-1.008 ＋0.012x and y =0.789-0.004x,y =-0.460 ＋0.006x and y =0.914-0.006x,respectively at the temperature-rise speeds of 0.4,0.7 and 1.0℃/4h.The linear regression equations between cumulative mortality and duration were：y =-0.737 ＋ 0.008x,y =-0.256 ＋ 0.004x and y =-0.490 ＋ 0.005x,respectively at the temperature-rise speeds of 0.4 0.7 and 1.0℃/4h.Cumulative coma rate and cumulative mortality were in significant linear relationship.The temperature-rise speeds of 0.7 and 1.0 ℃/4 h can be used as ideal temperature-rise modes,which can provide cold tolerant parents for the subsequent study on cold-resistant breeding of tilapia.