微生物菌剂联合叶面硅、铁对水稻Cd积累分布的影响

Effects of microbial fertilizer with foliar application of organosilicone and EDDHA-Fe on Cd accumulation in rice

【目的】探讨微生物菌剂联合叶面阻控剂对水稻Cd转移、积累的影响,为中轻度Cd污染农田安全生产提供重要参考。【方法】采用大田试验,选用有机硅和螯合铁作为叶面阻控剂,联合微生物菌剂,在田间共设置6个处理:水稻常规种植(CK)、叶面喷施有机硅和螯合铁(Y)、单独基施微生物菌剂—解淀粉芽孢杆菌和路德维希肠杆菌单独处理(D1、D2)、解淀粉芽孢杆菌和路德维希肠杆菌分别基施的同时叶面喷施有机硅和螯合铁(D1+Y、D2+Y),水稻成熟后测定各部位Cd含量。【结果】①与对照相比,叶面喷施有机硅和螯合铁处理水稻叶部Cd含量显著降低,TF_(根—秸秆)减小,根部Cd分配比例增加38.3%,叶面肥可有效阻隔Cd向水稻地上部的转移和积累。②解淀粉芽孢杆菌和路德维希肠杆菌菌剂基施对水稻Cd的积累有不同的影响。与对照相比,解淀粉芽孢杆菌基施水稻各部位Cd含量降低,Cd分配比例变幅较小;路德维希肠杆菌基施水稻叶部Cd含量降低,茎部、籽粒Cd含量显著增加,分别是对照的2.06、1.17倍,整株Cd积累量增加9.8%。③基施微生物菌剂联合叶面肥处理,水稻植株Cd积累量减少,且明显改变植株各部位Cd的分布。基施解淀粉芽孢杆菌菌剂联合叶面肥处理水稻TF秸秆—籽粒增大,籽粒Cd分配比例是对照的1.68倍,根部Cd分配比例是对照的63.5%,解淀粉芽孢杆菌联合叶面肥处理可增加Cd向地上部的转移。基施路德维希肠杆菌菌剂联合叶面肥处理水稻TF_(根—秸秆)比对照降低64.5%,根部Cd含量是对照的1.57倍,根部Cd分配比例增加57.7%,路德维希肠杆菌联合叶面肥处理可增加根部Cd的滞留,阻隔Cd向地上部转移。【结论】基施解淀粉芽孢杆菌菌剂,联合叶面喷施有机硅、螯合铁可降低水稻根部Cd积累,增加Cd向地上部转移;路德维希肠杆菌菌剂与叶面肥联合使用可有效降低水稻地上部Cd的积累,是中轻度Cd污染农田安全生产的重要措施之一。

[Objective]The present paper aimed to explore the effects of microbial agents combined with leaf barrier on the translocation and accumulation of Cd in rice,and provided important reference for the safe production of moderate and mild Cd contaminated farmland.[Method]The field experiment was adopted,organosilicon and chelated iron were selected as foliar control agents,combined with microbial agents,and a total of 6 treatments were set up in the field:conventional planting pattern(CK),spraying on the leaf with organosilicone and ED-DHA-Fe(Y),microbial agents derived from Bacillus amyloliquefaciens and Enterobacter ludwigii as base fertilizer applied separately to soil(DI and D2),microbial agents derived from B.amyloliquefaciens and E.ludwigii applied separately to soil,meanwhile spraying on the leaf with organosilicone and EDDHA-Fe(DI+Y and D2+Y).[Result](i)Leaf spraying with organosilicone and EDDHA-Fe significantly reduced the content of Cd in leaves,decreased TFroot_straw,and increased the proportion of Cd in roots by 38.3%,compared with the control.Foliar fertilizer could effectively prevent the translocation and accumulation of Cd to the shoot of rice.(ii)The two formulations of basal application of microbial agents had different effects on Cd accumulation in rice.Compared with the control,the content of Cd in different parts of rice was decreased by basal application of B.amyloliquefaciens,and the variation of Cd proportion was small.Applying with E.ludwigii,Cd content in leaves of rice decreased,and Cd content in stems and grains increased significantly,which were 2.06 and 1.17 times higher than those in control,respectively.Meanwhile,the accumulation of Cd in whole plant was increased by 9.8%.(iii)The accumulation of Cd in rice plants decreased and the distribution of Cd in different parts of rice was significantly changed by basal application of microbial agents combined with foliar fertilizer.When treated with DI+Y,the proportion of Cd in grains was 1.68 times higher than that in the control,and the proportion of Cd in roots was 63.5%equivalent to the control.The combination of microbial agent in B.amyloliquefaciens and foliar fertilizer could accelerate the translocation of Cd to the shoot and grains of rice.When treated with D2+Y,the TF_(root-straw) of Cd decreased by 64.5%compared with CK,the root Cd content was 1.57 times higher than that of the control,and the proportion of Cd in the root increased by 57.7%.Cd was restricted to the root by the combination of the basal application of E.ludwigii and foliar fertilizer,so that limited Cd was transferred to the shoot of rice.[Conclusion]The application of B.amyloliquefaciens agents,combined with leaf spraying of organosili-cone and EDDHA-Fe can reduce the accumulation of Cd in the root and increase the transfer of Cd to the shoot of rice.Combined application of E.ludwigii and foliar fertilizer can effectively reduce the accumulation of Cd in the straw and grain of rice,which is one of the important measures for the safety production of medium and mild Cd contaminated farmland.