秸秆还田对水稻镉积累及其亚细胞分布的影响  

Effects of Straw Incorporation on Cadmium Accumulation and Subcellular Distribution in Rice

作　　者：段桂兰[1] 王芳[1,2] 岑况[2] 王伯勋[1,3] 程旺大[4] 刘跃川[5] 张红梅 

机构地区：[1]中国科学院生态环境研究中心,北京100085 [2]中国地质大学地球科学与资源学院,北京100083 [3]首都师范大学资源环境与旅游学院,北京100048 [4]浙江省嘉兴市农业科学研究院,嘉兴314016 [5]湖南省攸县农业局,株洲412300

出　　处：《环境科学》2017年第9期3927-3936,共10页Environmental Science

基　　金：公益性行业(农业)科研专项(201403015);浙江省自然科学基金项目(LY15D010001);浙江省嘉兴市科技计划项目(2014AZ21001)

摘　　要：镉(Cd)是人类一级致癌物,大米食用是以大米为主食人群摄入Cd的主要途径.秸秆还田是秸秆处理中主要方式,在Cd污染稻田被广泛应用,其对水稻Cd吸收及水稻体内Cd的分布产生的影响不可忽视.本研究选用Cd水稻土,通过盆栽和大田试验分析了不同的秸秆还田用量(0.0%、1.0%、2.5%和5.0%)对Cd的亚细胞分布以及在水稻籽粒中积累的影响.结果表明水稻根细胞中的Cd主要分布在细胞壁中,占总Cd的86%~95%,茎叶细胞的细胞壁与可溶部分中的Cd含量相当,分别占总Cd的30%~51%和35%~61%.秸秆按1%和2.5%比例还田能显著提高根中Cd含量,以及细胞壁中Cd含量及其分配比例,并降低水稻体内Cd由根向茎叶转运;但5%的秸秆还田,分蘖期根中Cd含量和细胞壁中Cd含量显著降低,Cd由根向茎叶转运系数提高,灌浆期的根中Cd含量和细胞壁中Cd含量均显著提高,转运系数没有显著变化.大田试验前茬的水稻秸秆和油菜秸秆中Cd含量均较高,分别是0.49 mg·kg^(-1)和0.67 mg·kg^(-1);油菜秸秆单独还田或与石灰一起还田均没有显著影响水稻糙米或秸秆中Cd的积累;水稻秸秆单独还田也没有显著改变水稻糙米或秸秆中Cd的积累,但与石灰一起还田时能显著降低糙米和秸秆中的Cd积累;生物炭添加能显著降低水稻体内的Cd积累,且与石灰一起添加降Cd效果更显著.因此,当用Cd污染稻田前茬所产水稻秸秆还田时,建议与石灰一起添加可达到显著降Cd的效果.该研究将为Cd污染稻田的水稻安全生产与秸秆循环利用提供理论与实践指导.Cadmium（ Cd） is classified as a Group-1 human carcinogen and rice consumption constitutes a major source of dietary intake of Cd for populations whose staple food is rice. Straw incorporation is widely performed in Cd-contaminated paddy fields,which may significantly affect the bioavailability of Cd in soil and the distribution of Cd in rice plants,consequently altering Cd accumulation in rice grains. In this study,both pot and field trials were conducted to investigate the effects of different amounts of straw incorporation（ 0. 0%,1. 0%,2. 5%,and 5. 0%） on Cd sub-cellular distribution in rice plants and Cd accumulation in rice grains. The results showed that Cd was mainly sequestered in cell wall,accounting for 86%-95% and 30%-51% of total cadmium in root and shoot cells,respectively. In shoot cells,about 35%-61% of Cd was distributed in cellular soluble fractions. When rice straw was incorporated at1. 0% and 2. 5% levels,Cd sequestration in the cell wall significantly increased and Cd translocation from roots to shoots significantly decreased. However,when rice straw was incorporated at the 5% level,Cd sequestration in root cell walls significantly decreased and Cd translocation from roots to shoots significantly increased at the tillering stage. At the filling stage,5% rice straw incorporation still significantly increased Cd sequestration in root cell walls and Cd translocation from roots to shoots did not significantly change. The rice straw and rape straw used for the field trail contained high concentrations of Cd（ 0. 49 and 0. 67 mg·kg^-1,respectively）. Rape straw incorporation alone or together with lime did not significantly affect Cd accumulation in brown rice or rice straw. Rice straw incorporation alone did not significantly affect Cd accumulation in brown rice or rice straw,while incorporation with lime significantly decreased Cd accumulation in both brown rice and rice straw. Biochar application can also significantly reduce Cd accumulation in rice and when biochar was added together w

关 键 词：水稻 镉 秸秆还田 亚细胞分布 细胞壁 转运系数 

分 类 号：X171.5[环境科学与工程—环境科学]