<正>平原地区河流的富营养化已日益受到重视，当外源营养物质的输入得到控制时，河流内源污染物的释放规律研究是防治、修复和治理河流富营养化的重要决策工具。笔者分析了内源磷的赋存形态，总结了影响内源磷释放的环境因子，如pH、温度、溶解氧、微生物的活动、氧化还原电位、周期性的水淹、水生植物、硝酸盐以及河流水动力条件等，指出了当前研究的不足，并提出了相应的解决方法。针对浅水河滨带有水生植物分布的特点，认为不同水动力条件和水生植物对内源磷释放及吸收的影响更具有意义。

The effects of different types and concentrations of plant growth regulators on callus tissue induction of cotyledons and hypocotyls of Chaenomeles speciosa Nakai were studied. The results showed that 2,4-D had a better effect on inducing and subculture callus tissue than that of NAA in the experiment of cotyledons. A satisfactory result of callus tissue induction and callus growth was achieved on MS medium supplemented with 1.0mg/L 2,4-D and 0.1mg/L KT. Callus tissue induction rate of hypocotyls was 87%, which was higher than that of cotyledons, i.e., 69%. The proportion and the degree of callus tissue vitrifaction would scale up when the concentration of auxin and BA increased. Best callus tissue of hypocotyls were obtained on MS medium contained 0.1=mg/L 2,4-D and 0.3mg/L BA.