磷肥种类对李氏禾富集铜、铬的影响及其生理响应

植物修复是现下环境和生态领域研究的热门话题。环境中的铜、铬等重金属复合污染问题越发严重,在水环境修复和治理的方法中,植物修复技术的优越性越发显著。该文旨在加深磷对李氏禾累积重金属铜和铬复合污染的认识。施磷是一种重要的农艺措施,其在提高植物修复复合污染水体效率方面的效果不容忽视。该实验研究李氏禾(Leersia Hexandra Swartz)分别在磷酸氢二铵(DAP)、磷酸二氢铵(MAP)、磷酸氢钙(DCP)、过磷酸钙(SSP)4种磷肥的不同质量浓度(无磷0 mg·L^?1、低磷11.38 mg·L^?1、中磷22.76 mg·L^?1和高磷45.52 mg·L^?1),Cu(II)、铬(VI)质量浓度均为10 mg·L^?1的复合污染水体下的重金属累积影响和生理响应。结果表明:在中磷浓度下,施加SSP后李氏禾对铜、铬的富集能力最大,为0P处理组的1.8—3.4倍,均高于其他处理组且存在显著性差异(P<0.05)。在高磷浓度处理下,施加(NH4)2HPO4处理组李氏禾生物量为9.260 g·10 plants?1,株高为59.07 cm,叶绿素含量为4.889 mg·g^?1,可溶性蛋白含量为10.77 g·L?1,均高于其他处理组且达到显著性差异(P<0.05)。在中磷浓度处理下,SSP处理组李氏禾叶片中丙二醛(MDA)含量为1.251μmol·g?1,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的含量分别为4.765、3.077、10.16 U·mg^?1(以prot.计),均高于其他处理组且达到显著性差异(P<0.05)。适量施加磷肥可以有效地提高李氏禾的生物量,以及各组织对铜、铬的累积作用,这一结果提高了我们对磷在植物修复技术中的作用的认识。

Effect of Phosphate Forms on Enrichment of Cu and Cr by Leersia Hexandra Swartz and Physiological Response

Phytoremediation is a hot topic in the field of environment and ecology.The pollution of heavy metals such as copper and chromium in the ecological environment is becoming more and more serious.Phosphorus application is an important agronomic measure,but its effect on improving the efficiency of phytoremediation has rarely been reported in environmental remediation studies.The primary objective of this work is to improve understanding of the impacts of heavy metals such as Cu and Cr in Leersia Hexandra Swartz and to provide theoretical data for phytoremediation of contaminated water.This study analyzed the Cu and Cr-accumulation in L.hexandra,the plant growth and its physiological responses under different concentrations(low:11.38 mg·L^?1;Medium:22.76 mg·L^?1;high:45.52 mg·L^?1)of four phosphate fertilizers((NH4)2HPO4,NH4H2PO4,CaHPO4,Ca(H2PO4)2)for fifteen days.The heavy metal concentrations of copper and chromium were set at 10 mg·L^?1.The result indicated that when the P concentration was 22.76 mg·L^?1,the highest mean levels of Cu and Cr-accumulation(roots:674.125 mg·kg?1,stem:89.250 mg·kg?1,leaf:57.750 mg·kg?1 and roots:828.083 mg·kg?1,stem:202.000 mg·kg?1,leaf:64.000 mg·kg?1)were detected in Ca(H2PO4)2 treatment,which had significant difference from other treatment group(P<0.05).However,under high P concentrations level,DAPtreatment had the tallest plant height and largest biomass(9.260 g·10 plant?1 and 59.067 cm,respectively).The content of chlorophyll and soluble prote were 4.889 mg·g^?1and 10.773 gprot·L?1,respectively,which had significant difference from other treatment group(P<0.05).Under high P concentrations level,the content of MDA,SOD,POD,CAT in the leaves of the SSP treatment group was higher than that of the other treatment groups.The content of MDA,SOD,POD,CAT were 1.251 mol·g^?1,4.765 U·mgprot?1,3.077 U·mgprot?1 and 10.16 U·mgprot?1,respectively,which had significant difference from other treatment group(P<0.05).Proper application of phosphorus fertilizer could effectively improve the biomass and the accumulation of copper and chromium in various tissues,which enhanced our understanding of the role of phosphorus in phytoremediation technology.