【摘要】 本文对水霉的生态学研究技术进行了探索,改进了水霉定量分离的方法,鉴定和筛择了有利于水霉纯化和分离的选择性培养基,同时对水霉在自然界的存在规律进行了研究,调查了5种不同污染程度水体中水霉数量的季节性分布,结果表明,从清洁水到重污水体中水霉的数量具有季节性分布,除重污水体外,其它水体一般在一年内出现三次高峰。对水霉在水体中的昼夜分布和垂直分布也作了初步调查。更多还原

【Abstract】 A method of estimating the numbers of saprolegniaceous propagules by using PVC "V" type seriological plate and tobacco seed baits was developed. This method commits less errors and saves a lot of labour and time. A selective medium (PRPAM) that permits the growth of several associated organisms was prepared and tested. PRPAM contains the following ingredients per liter CMA: 10 mg pimarycin, 10 mg rifampicin, 100 mg PCNB, 200 mg ampecillin and 50 mg metalaxyl. In the meantime, the quantitative changes in the populations of Saprolegniaceae in different polluted waters (such as fresh water, β-oligo, aoligo-β-moderate, a-moderate and serious polluted) were sampled, observed, analyzed and recorded throughout a period of a whole year. The result showed that there was a seasonal periodicity in number of the propagules with three, rather than two, maxima: early spring, late spring and late autumn (except in the case of serious polluted water). However, the maximum deviation in moderate polluted water occurred in hot polluted waters. The diurnal fluctuation and vertical distribution of the number of saprolegniaceous propagules were also investigated in β-oligo polluted water.更多还原