不同年度收存的褶皱臂尾轮虫休眠卵的孵化及滞育胚胎“激活”效果的研究

比较了 1 985— 1 998年间由同一褶皱臂尾轮虫 (Brachionusplicatilis)种群在实验室内历年产生并收存的休眠卵的孵化效果 ,并初步探讨了胚胎“激活”处理对孵化的影响。结果表明 ,休眠卵的收存年度或时间对其在一定孵育期内的总孵化率 (THR)和日孵化率 (DHR)有极显著影响 (x2 检验 ,p<0 .0 0 1 ) ,但THR和DHR与储存时间间均无显著的相关性 ,而是呈极大波动。同时发现“激活”作用具有促使孵化高峰提前到来、增强孵化同步性的双重功效 ,从而可明显缩短孵育时间 ,提高孵化速率。但“激活”前后多数卵样的总孵化率无显著变化 (p >0 .0 5 )。详细讨论了可能导致孵化率波动的多种因素 ,例如遗传变异、培养历史、储存及孵化的环境条件等。

STUDY ON HATCHING OF ROTIFER RESTING EGGS ( BRACHIONUS PLICATILIS) COLLECTED AND PRESERVED IN DIFFERENT YEARS AND EFFECT OF ADVANCE ACTIVATION ON DIAPAUSE EMBRYOS

This paper investigated the hatching performances of resting eggs that were produced by a single stock of rotifer Brachionus plicatilis (Qiandao strain) in laboratory and collected/preserved annually during 1985-1998; the effect of advance activation treatment to diapause egg embryos on hatching was preliminarily studied as well. The results obtained from 4 days of incubation period showed that, the collection and preservation time had extremely significant effect ( x 2 -test, p <0.001) on both the total hatching rate ( THR ) and the daily hatching rate ( DHR ) among the 14 batches (years) of egg samples. Significant fluctuations, rather than a linear relationship, were found among their hatching rates as the preservation period extended. At the same time, marked effects of the "activation" on hatching performances of tested egg samples was observed: it not only significantly advanced the appearing time of the maximum DHR (i.e. hatching peak) ( p <0.001) but also further enhanced the simultaneity of hatching, resulting in incubation period shortened by half. However, the activation did not significantly change the THR of most of the tested egg samples ( p >0.05). Various internal and external factors (such as genetic changes, culture history, preservation and incubation conditions) possibly causing the above "fluctuation" were thoroughly discussed.