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【目的】以广东大宝山重金属复合污染农田为生长介质,通过研究水稻不同部位生长量、金属含量、对金属的富集系数,及其与根际、非根际土金属含量、形态变化的相关关系,探讨根际效应可能对水稻体内金属积累转运以及生物量的影响。【方法】选取了广东大宝山稻田重金属复合污染(As、Pb、Fe、Cu、Zn)土壤及当地常见的20个水稻品种进行根际袋试验,即将根际袋内的土视为根际土,根际袋外的土视为非根际土,将供试水稻品种种植于根际袋土壤中60天后收获,测定水稻各部位的生长量、不同金属的含量,根际土和非根际土中各金属有效态的含量。【结果】Fe、Cu、Pb、Zn、As在根部的富集系数均大于其在茎叶的富集系数,各金属在茎叶和根部的富集能力排序分别为Zn>Cu>As≈Pb≈Fe和Fe>Zn>As>Cu>Pb。根际土和非根际土中各种金属有效态含量均为Fe>Cu>Pb>Zn>As。研究还发现,有效态Fe、Cu和Zn浓度对整株干重的影响显著,作用强弱顺序为Cu>Zn>Fe,对水稻生长影响作用显著的三种有效态金属Fe、Cu和Zn均为植物生长所必需的元素。供试土壤中有效态Cu浓度对水稻的生长所起的作用最强。根际土有效态Fe浓度对根系Fe的积累作用效果显著,有效态As浓度显著抑制了根系Fe的积累,且有效态As浓度的作用强于有效态Fe。【结论】根际土中有效态Fe对株高、根干重、茎叶干重和整株干重均起着抑制作用,有效态Cu对水稻生长起到了促进作用。根际土有效态As和非根际土有效态Zn对根部Fe的积累起到了抑制作用,根际土有效态Fe和非根际土有效态Cu则起到了促进作用。非根际土有效态Fe和有效态Zn对水稻根长的增加均起到了促进作用。
【Objective】 The objective of this study was to investigate the effects of heavy metal pollution in farmland of Dabashan, Guangdong Province on the growth of rice, growth of different parts of rice, metal content, enrichment coefficient of the metal and its relationship with rhizosphere and non-rhizosphere soil contents and morphological changes The effects of rhizosphere effect on metal accumulation, transport and biomass in rice were also investigated. 【Method】 A total of 20 rice cultivars contaminated by heavy metals (As, Pb, Fe, Cu, Zn) in paddy field of Dabashan, Guangdong Province were selected for rhizosphere test. The rhizosphere soil was considered as rhizosphere soil , The soil outside the rhizosphere pocket was considered as non-rhizosphere soil. The tested rice varieties were harvested in rhizosphere soil for 60 days and harvested. The growth of different parts of rice, the contents of different metals, rhizosphere soil and non-rhizosphere Earthen metal content of the effective state. 【Result】 The results showed that the enrichment coefficients of Fe, Cu, Pb, Zn and As in roots were greater than those in stems and leaves. The order of enrichment ability of each metal in stems, leaves and roots was Zn> Cu> As≈Pb ≈Fe and Fe> Zn> As> Cu> Pb. The available metal contents in rhizosphere soil and non-rhizosphere soil were Fe> Cu> Pb> Zn> As. The results also showed that the effective concentrations of Fe, Cu and Zn had a significant effect on the dry weight of the whole plant, and the order of the effect was Cu> Zn> Fe. The three effective metals Fe, Cu and Zn, all of which had a significant effect on rice growth The necessary elements for plant growth. The available Cu concentration in the soil tested had the strongest effect on rice growth. The effective Fe concentration in rhizosphere soil has a significant effect on the accumulation of Fe in roots, the effective As concentration significantly inhibits the accumulation of Fe in roots, and the effect of As concentration is stronger than that of Fe. 【Conclusion】 Effective Fe in rhizosphere soil can inhibit plant height, dry root weight, dry weight of stem and leaf and dry weight of whole plant, and Cu in active state can promote rice growth. Rhizosphere soil available As and non-rhizosphere soil effective Zn inhibited the root Fe accumulation, and rhizosphere soil active Fe and non-rhizosphere soil active Cu played a promoting role. The effective Fe and available Zn in non-rhizosphere soil all play an active role in increasing the root length of rice.