水溶性有机物对黑麦草吸收铜的影响

Effects of dissolved organic matter on copper absorption by ryegrass

采用水培试验,研究蚓粪及蚯蚓培养载体牛粪中水溶性有机物(DOM)对不同Cu2+浓度下(0、5、10mg.L-1)黑麦草吸收Cu2+的影响.结果表明:随着Cu2+浓度的增加,黑麦草地上部、根干质量,以及根系的长度、表面积、体积和根尖数均逐渐下降;DOM显著增加了Cu2+处理下黑麦草地上部及根系生物量,促进了其根系的长度、表面积、体积和根尖数的增长.DOM降低了黑麦草地下部Cu2+浓度,促进了Cu2+从地下部向地上部的运输,显著增加了地上部Cu2+积累量.蚓粪DOM对黑麦草的影响优于牛粪DOM,并且供试高浓度DOM效果优于低浓度.

In this study,dissolved organic matter（DOM） was extracted from earthworm casts and from the cattle manure with which the earthworms were fed,and a water culture experiment was conducted to study the effects of the DOM on the copper（Cu2＋） absorption by ryegrass in the presence of different concentration Cu2＋（0,5 and 10 mg ·L-1）.With the increasing concentration of Cu2＋ in the medium,there was a gradual decrease in the dry mass of ryegrass shoots and roots and in the root length,surface area,volume,and tip number.In the presence of medium Cu2＋,DOM increased the biomass of shoots and roots and the root length,surface area,volume,and tip number significantly.DOM reduced the Cu2＋ concentration in roots,promoted the Cu2＋ translocation from roots to shoots,and significantly increased the Cu2＋ accumulation in shoots.The DOM from earthworm casts had better effects than that from cattle manure,and high concentration DOM had better effects than low concentration DOM.