水溶性有机物对黑麦草吸收铜的影响

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、10 mg·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.

Effects of dissolved organic matter on copper absorption by ryegrass

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.