Cd胁迫水培试验下水稻糙米Cd累积的关键生育时期

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王倩倩^,, 贾润语, 李虹呈, 周航^,, 杨文弢, 辜娇峰, 彭佩钦, 廖柏寒^,中南林业科技大学环境科学与工程学院/稻米品质安全控制湖南省工程实验室,长沙 410004

Key Growth Stage of Cd Accumulation in Brown Rice Through a Hydroponic Experiment with Cd Stress

WANG QianQian^,, JIA RunYu, LI HongCheng, ZHOU Hang^,, YANG WenTao, GU JiaoFeng, PENG PeiQin, LIAO BoHan^,College of Environment Science and Engineering, Central South University of Forestry and Technology/Hunan Engineering Laboratory for Control of Rice Quality and Safety, Changsha 410004

通讯作者: 周航,E-mail： zhouhang4607@163.com。廖柏寒,E-mail： liaobh1020@163.com

第一联系人: 王倩倩,E-mail： 13657319540@163.com。
责任编辑: 杨鑫浩
收稿日期:2018-06-13接受日期:2018-08-14网络出版日期:2018-12-01

基金资助:

国家重点研发计划.2016YFD0800705
国家自然科学基金.41501344
湖南省重点学科建设项目.2006180
研究生科技创新基金项目.20183022

Received:2018-06-13Accepted:2018-08-14Online:2018-12-01

摘要
【目的】探究水稻不同生育时期Cd胁迫对水稻成熟期糙米Cd累积的影响,明确糙米Cd累积关键生育时期,以期适时采取阻控措施降低糙米Cd含量,为水稻安全生产提供理论参考。【方法】以水稻品种湘晚籼13号（晚稻品种）为研究对象,采用水培试验,共设计7个添加外源Cd处理,即CG（全生育时期Cd胁迫,102 d）、TS（分蘖期Cd胁迫,15 d）、JS（拔节期Cd胁迫,15 d）、BS（孕穗期Cd胁迫,21 d）、FS（灌浆期Cd胁迫,18 d）、DS（腊熟期Cd胁迫,15 d）、MS（成熟期Cd胁迫,18 d）,以全生育时期无Cd胁迫作为空白对照（CK）,每个处理重复3次。各处理外源Cd胁迫浓度相同,均为20 μg·L ^-1。水培试验于2017年7月23日开始,在湖南省长沙市中南林业科技大学水稻试验基地进行。2017年11月19日,水稻成熟后,整株采集水稻,测定指标为不同生育时期Cd胁迫下水稻农艺性状（株高、分蘖数和各部位生物量）和水稻各部位（根、茎、叶、穗、谷壳和糙米）Cd含量,计算水稻各部位Cd累积量以及不同生育时期Cd累积对成熟期糙米Cd累积的相对贡献率。【结果】不同生育时期Cd胁迫对水稻株高、分蘖数以及各部位生物量没有显著影响。灌浆期Cd胁迫下,水稻成熟期糙米Cd含量最高,为1.05 mg·kg ^-1,显著高于水稻成熟期（0.57 mg·kg ^-1）、孕穗期（0.52 mg·kg ^-1）、腊熟期（0.38 mg·kg ^-1）、拔节期（0.31 mg·kg ^-1）和分蘖期（0.17 mg·kg ^-1）Cd胁迫下糙米Cd含量。各生育时期Cd胁迫下水稻成熟期糙米Cd累积量范围为0.18—1.56 μg/株,糙米Cd累积量大小顺序为：全生育时期Cd胁迫>灌浆期Cd胁迫>成熟期Cd胁迫>孕穗期Cd胁迫>拔节期Cd胁迫>分蘖期Cd胁迫。孕穗期、灌浆期和成熟期是水稻糙米Cd累积的关键生育时期,对成熟期糙米Cd累积相对贡献率分别为19.7%、39.3%和22.6%,而分蘖期、拔节期和腊熟期的Cd累积对成熟期糙米Cd累积相对贡献较小,贡献率分别为2.4%、4.2%和11.9%。除全生育时期Cd胁迫外,水稻根、茎、穗和谷壳Cd含量均在孕穗期和灌浆期Cd胁迫下较高;各生育时期Cd胁迫下,水稻叶Cd含量无显著性差异。孕穗期和灌浆期Cd胁迫下根Cd累积量较高,分别为86.09 μg/株和79.23 μg/株,显著高于其他生育时期Cd胁迫下根Cd累积量（31.55—40.37 μg/株）。与其他生育时期Cd胁迫相比,水稻植株Cd总累积量在孕穗期和灌浆期Cd胁迫下较高,分别为107.13 μg/株和98.35 μg/株,显著高于其他生育时期Cd胁迫下水稻植株Cd总累积量（42.24—52.47 μg/株）。【结论】水稻的孕穗期、灌浆期和成熟期是控制水稻糙米Cd累积的关键时期。在孕穗期和灌浆期Cd胁迫下,水稻成熟期根和糙米累积Cd最多,因此可以在水稻孕穗期和灌浆期施加改良剂阻隔根系吸收Cd或者阻隔根系吸收的Cd向糙米中转运,从而降低水稻糙米中Cd的累积。
关键词： 水稻;水培试验;Cd胁迫;生育时期;Cd累积

Abstract

【Objective】 The objectives of this study were to explore the effects of Cd stress on Cd accumulation in brown rice at different growth stages (tillering stage, jointing stage, booting stage, filling stage, dough stage, and maturing stage) of rice plants, to clear and definite the key growth stages of rice plants for Cd accumulating in brown rice, so as to provide directions of rice safety production by taking suitable measures timely for reducing Cd contents in brown rice. 【Method】 Taking Xiangwanxian 13 (a late rice variety) as the studied plant, a hydroponic experiment with rice plants was conducted with seven treatments of exogenous Cd application, including CG (whole growth stages with Cd stress, 102 d), TS (tilling stage with Cd stress, 15 d), JS (jointing stage with Cd stress, 15 d), BS (booting stage with Cd stress, 21 d), FS (filling stage with Cd stress, 18 d), DS (dough stage with Cd stress, 15 d), and MS (maturing stage with Cd stress, 18 d). All seven treatments were repeated 3 times and another treatment of the whole growth stages without Cd stress as control (CK). Exogenous Cd in each treatment was the same as 20 μg·L ^-1. The hydroponic experiment started in July 23, 2017, at the rice experiment base of Central South University of Forestry and Technology in Changsha, Hunan province. Agronomic characters (plant height, tiller number, and biomass of rice tissues) and Cd contents in various rice tissues were determined after harvest in November 19, 2017. Cd amounts and the relative contribution rates of Cd accumulation at different growth stages to Cd accumulation in brown rice at maturing stage were calculated. 【Result】 The results showed that exogenous Cd application at different growth stage of rice plants did not affect plant height, tiller number, and biomass of rice tissues. At the filling stage with Cd stress, Cd contents in brown rice was the highest and reached to 1.05 mg·kg ^-1, which was significantly higher than Cd contents in brown rice with Cd stress at the maturing stage (0.57 mg·kg ^-1), booting stage (0.52 mg·kg ^-1), dough stage (0.38 mg·kg ^-1), jointing stage (0.31 mg·kg ^-1), and tilling stage (0.17 mg·kg ^-1). The range of Cd amounts in brown rice with Cd stress at different growth stages were 0.18-1.56 μg/plant, and the sequence of Cd amounts were: whole growth stages with Cd stress>filling stage with Cd stress>maturing stage with Cd stress>booting stage with Cd stress>jointing stage with Cd stress>tilling stage with Cd stress. The booting stage, filling stage and maturing stage of rice plants were the key growth stages for Cd accumulating in brown rice, and the relative contribution rates of Cd accumulating in brown rice at these three growth stages were 19.7%, 39.3%, and 22.6%, respectively. The contributions of Cd stress to Cd accumulating in brown rice were 2.4%, 4.2%, and 11.9% at the tillering, jointing, and dough stage, respectively, which were relatively lower compared with the other three stages. Cd contents in rice roots, stem, ear, and husk at booting stage and filling stage were all higher except the whole growth stages with Cd stress. There was no significant difference in Cd content in rice leaves (P>0.05) at different growth stages with Cd stress. At the tillering stage and filling stage with Cd stress, Cd amounts in rice roots were 86.09 μg/plant and 79.23 μg/plant, respectively, which was significantly higher than those at the other stages of rice plants (31.55-40.37 μg/plant). Compared to the other stages, Cd amounts in rice plants at the booting stage and filling stage with Cd stress were high, reaching 107.13 μg/plant and 98.35 μg/plant, respectively, which was significantly higher than those at the other four stages of rice plants (42.24-52.47 μg/plant). 【Conclusion】 The booting stage, filling stage, and maturing stage of rice plants were the key growth stages for controlling Cd accumulation in brown rice. With Cd stress at the booting stage and filling stage, the Cd accumulation in the root and brown rice at the maturing stage were higher than those other stages. Therefore, the Cd accumulation in brown rice could be reduced by applying soil amendments at the booting stage and filling stage of rice plants to obstruct root absorbing Cd or reducing Cd transportation from rice root to brown rice.

Keywords：rice (Oryza sativa L.);hydroponic experiment;Cd stress;growth stage;Cd accumulation

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本文引用格式
王倩倩, 贾润语, 李虹呈, 周航, 杨文弢, 辜娇峰, 彭佩钦, 廖柏寒. Cd胁迫水培试验下水稻糙米Cd累积的关键生育时期[J]. 中国农业科学, 2018, 51(23): 4424-4433 doi:10.3864/j.issn.0578-1752.2018.23.003
WANG QianQian, JIA RunYu, LI HongCheng, ZHOU Hang, YANG WenTao, GU JiaoFeng, PENG PeiQin, LIAO BoHan. Key Growth Stage of Cd Accumulation in Brown Rice Through a Hydroponic Experiment with Cd Stress[J]. Scientia Acricultura Sinica, 2018, 51(23): 4424-4433 doi:10.3864/j.issn.0578-1752.2018.23.003

0 引言

【研究意义】我国土壤重金属污染日益严重,土壤Cd点位超标率为7.0%^[1]。水稻（Oryza sativa L.）是我国重要的粮食作物^[2],对Cd富集能力强^[3],土壤中的Cd能够被水稻吸收和累积,通过食物链危害人体健康^[4]。探究水稻Cd吸收与累积的机理,控制土壤Cd向水稻的迁移是目前的研究热点。【前人研究进展】研究发现,糙米中的Cd不仅来源于水稻成熟期吸收的Cd,还包括水稻孕穗期前吸收的Cd^[5,6],这一部分Cd在水稻生长后期进行转移,并在灌浆期随营养物质传输而在糙米中累积^[7,8,9]。近年来,一些研究将水稻不同生育时期作为控制稻田Cd污染的重点,不仅仅注重对水稻成熟期Cd吸收累积状况的研究。张振兴等^[10]研究发现,在水稻插秧前、分蘖期、孕穗期、灌浆期施用生石灰能够有效降低成熟期糙米Cd含量,与对照相比分别下降了55.6%、48.6%、22.2%和22.2%。靳磊等^[11]研究表明,在水稻分蘖期和孕穗期喷施叶面Zn肥,可以显著降低成熟期糙米Cd含量,与未喷施相比分别降低了45.9%和47.5%。【本研究切入点】水稻成熟期糙米中的Cd并不全部来源于灌浆期到成熟期水稻根系对土壤Cd的吸收,还包括了水稻生育前期已经累积在水稻根系以及茎叶中Cd的再转运。因此,我们认为在水稻某个特定生育时期添加外源Cd,成熟期糙米Cd的累积量应该在一定程度上反映这一生育时期Cd胁迫对成熟期糙米Cd累积的影响。为了印证这一推测,在前人研究基础上^[7,12-13],我们开展了不同水稻生育时期Cd胁迫下的水培试验。【拟解决的关键问题】明确不同生育时期Cd胁迫对糙米Cd的影响,及确定水稻体内Cd累积的关键生育时期。

1 材料与方法

1.1 供试材料

供试水稻为湘晚籼13号,常规晚籼品种,由湖南省水稻研究所和金健米业股份有限公司合作选育;水稻培养营养液采用木村营养液^[14]。

1.2 试验设计

水培试验在中南林业科技大学生命科学楼水稻试验基地进行,该基地光、气、热均为自然状态。该地区为亚热带季风性气候,降水丰沛,气候温和,雨热同期。2017年7月10日,水稻种子用30% H₂O₂消毒15 min,用去离子水洗净,再用湿润的纱布包裹,置于人工培养箱（温度30℃,湿度50%）中培养发芽,芽长至1 cm左右,播种于未受Cd污染的土壤中。2017年7月23日,将水稻幼苗（三叶一心）根系用自来水冲洗,去除根系附着的黏土,用海绵包裹、泡沫浮板固定水稻幼苗,放入装有18 L营养液的无盖长方体容器（长50 cm、宽25 cm、高15 cm）中进行前期培养,使水稻幼苗正常生长,满足后期试验要求。2017年8月11日选择长势均匀一致的水稻幼苗,五叶一心,1穴2株,移入装有2.5 L营养液的圆柱形塑料桶中（内径20 cm,高24 cm）进行水培试验。根据试验设计要求在不同生育时期添加外源Cd,使营养液中Cd²⁺浓度达到20 μg·L^-1[6,13,15]（外源Cd由CdCl₂·2.5H₂O配制）,每3 d更换一次营养液,同时控制营养液的pH在5.5左右（以NaOH和HCl调节）。试验共设计7个添加外源Cd处理,即CG（全生育时期Cd胁迫,102 d）、TS（分蘖期Cd胁迫,15 d）、JS（拔节期Cd胁迫,15 d）、BS（孕穗期Cd胁迫,21 d）、FS（灌浆期Cd胁迫,18 d）、DS（腊熟期Cd胁迫,15 d）、MS（成熟期Cd胁迫,18 d）,以全生育时期无Cd胁迫作为空白对照（CK）,每个处理重复3次,具体试验设计见表1。根据实际情况喷洒农药,防止病虫害。

Table 1
表1
表1试验设计
Table 1Experimental design

处理 Treatment	胁迫时间 Stress time (d)	试验处理 Experimental treatment	胁迫时期 Stress stage
CK	0	不添加外源Cd,仅在自来水中添加营养液 Adding nutrient solution to tap water without exogenous Cd	无 No
TS	15	水稻幼苗移栽后在营养液中添加外源Cd使营养液中的Cd浓度保持在20 μg·L^-1,加Cd至分蘖期结束 Adding exogenous Cd to nutrient solution until to the end of tillering stage after transplanting, and keeping Cd concentration in nutrient solution at 20 μg·L^-1	分蘖期 Tillering stage
JS	15	水稻分蘖期结束开始加外源Cd使营养液中的Cd浓度保持在20 μg·L^-1,加Cd至拔节期结束 Adding exogenous Cd to nutrient solution from the end of tillering stage to the end of jointing stage, and keeping Cd concentration in nutrient solution at 20 μg·L^-1	拔节期 Jointing stage
BS	21	水稻拔节期结束开始加外源Cd使营养液中的Cd浓度保持在20 μg·L^-1,加Cd至孕穗期结束 Adding exogenous Cd to nutrient solution from the end of jointing stage to the end of booting stage, and keeping Cd concentration in nutrient solution at 20 μg·L^-1	孕穗期 Booting stage
FS	18	水稻孕穗期结束开始加外源Cd使营养液中的Cd浓度保持在20 μg·L^-1,加Cd至灌浆期结束 Adding exogenous Cd to nutrient solution from the end of booting stage to the end of filling stage, and keeping Cd concentration in nutrient solution at 20 μg·L^-1	灌浆期 Filling stage
DS	15	水稻灌浆期结束开始加外源Cd使营养液中的Cd浓度保持在20 μg·L^-1,加Cd至腊熟期结束 Adding exogenous Cd to nutrient solution from the end of filling stage to the end of dough stage, and keeping Cd concentration in nutrient solution at 20 μg·L^-1	腊熟期 Dough stage
MS	18	水稻腊熟期结束开始加外源Cd使营养液中的Cd浓度保持在20 μg·L^-1,加Cd至成熟期结束 Adding exogenous Cd to nutrient solution from the end of dough stage to the end of maturing stage, and keeping Cd concentration in nutrient solution at 20 μg·L^-1	成熟期 Maturing stage
CG	102	水稻幼苗移栽后在营养液中添加外源Cd使营养液中的Cd浓度保持在20 μg·L^-1,加Cd至成熟期结束 Adding exogenous Cd to nutrient solution until to the end of maturing stage after transplanting, and keeping Cd concentration in nutrient solution at 20 μg·L^-1	全生育时期 Whole growth stages

表中TS代表分蘖期,JS代表拔节期,BS代表孕穗期,FS代表灌浆期,DS代表蜡熟期,MS代表成熟期,CG代表全生育时期。下同
In this table, TS represents tilling stage, JS represents jointing stage, BS represents booting stage, FS represents filling stage, DS represents dough stage, MS represents maturing stage, and CG represents the whole growth stages. The same as below

新窗口打开|下载CSV

2017年11月19日,收获水稻植株,先用自来水冲洗去除水稻表面浮土,再用去离子水清洗3次。将根系剪下,用去离子水冲洗数次,然后放入5 mmol·L^-1的CaCl₂溶液浸泡15 min,以去除根系表面吸附的Cd^{2+ [16]}。然后将根及洗净的其他水稻部位自然风干后放入烘箱,105℃杀青30 min,70℃烘干至恒重,分别记录根、茎、叶、穗、谷壳和糙米的干重,所有样品粉碎并用密封袋保存待测。

1.3 样品分析测定方法

水稻样品采用干灰法进行消解（GB/T 5009—2003）,水稻样品溶液中的Cd含量使用石墨炉原子吸收分光光度计（iCE-3500,Thermo）测定。所有样品分析过程中以湖南大米（GBW 10045（GSB-23））进行质量控制,Cd的回收率为98.2%—101.8%,同时做空白试验。

1.4 数据统计与分析

水稻各部位（根、茎、叶、穗、谷壳、糙米）Cd累积量（μg/株）用BA_i表示^[17]：

BA_i=C_i×B_i

式中,C_i是水稻各部位（根、茎、叶、穗、谷壳、糙米）Cd 含量（mg·kg^-1）,B_i是水稻各部位生物量（干重,g/株）。

水稻植株Cd累积量=∑BA_i

水稻不同生育时期Cd累积对成熟期糙米Cd累积相对贡献率用P表示：

P=(C_j×B_j-C_k×B_k)/∑(C_j×B_j-C_k×B_k)×100%

式中,C_j是不同生育时期Cd胁迫（分蘖期、拔节期、孕穗期、灌浆期、腊熟期、成熟期）下糙米Cd 含量（mg·kg^-1）,B_j是不同生育时期Cd胁迫下糙米生物量（干重,g/株）,C_k是全生育时期无Cd胁迫下糙米Cd 含量（mg·kg^-1）,B_k是全生育时期无Cd胁迫下糙米生物量（干重,g/株）。

本研究数据统计与分析采用SPSS19.0 Duncan多重比较法（P<0.05）,图形采用Origin 9.0进行绘制。

2 结果

2.1 不同生育时期Cd胁迫对水稻生长的影响

对成熟期水稻株高、分蘖数和生物量进行测定（表2）,各处理间水稻生长差异不明显。从水稻生物量来看,各处理糙米生物量与对照（CK）均不存在显著差异（P>0.05）;与全生育时期Cd胁迫（CG）相比,除MS处理的茎生物量之外,其余处理均不存在显著差异（P>0.05）;MS处理与JS和FS处理的谷壳生物量之间存在显著差异（P<0.05）。各处理水稻株高与CK和CG处理均不存在显著差异（P>0.05）。JS处理的分蘖数最多,且与CG处理存在显著差异（P<0.05）。

Table 2
表2
表2不同生育时期Cd胁迫对水稻生长的影响
Table 2Effects of Cd stress at different rice growth stages on growth of rice plants

处理 Treatment	株高 Plant height (cm)	分蘖数 Tiller number	水稻各部位生物量 Cd contents in rice tissues (g/plant)
处理 Treatment	株高 Plant height (cm)	分蘖数 Tiller number	糙米 Brown rice	谷壳 Husk	穗 Ear	叶 Leaf	茎 Stem	根 Root	总生物量 Total biomass
CK	105.7±4.7a	17±1ab	1.5±0.5a	7.6±2.2ab	1.9±1.0a	14.6±1.2a	23.2±2.6ab	8.0±0.4a	56.8±3.8a
CG	106.7±4.7a	15±1b	1.6±0.1a	8.4±2.1ab	2.4±0.2a	17.2±2.4a	15.9±2.5b	7.0±0.5a	52.4±2.8a
TS	105.0±4.1a	15±1b	1.1±0.1a	5.5±0.8ab	2.4±0.2a	17.6±4.4a	18.6±4.1ab	7.0±1.3a	52.2±6.7a
JS	101.7±2.4a	22±1a	0.9±0.5a	4.1±1.8b	2.9±0.9a	14.8±5.0a	19.8±4.7ab	8.3±2.0a	50.8±14.0a
BS	103.3±9.4a	17±1ab	1.4±0.4a	6.2±4.2ab	2.3±0.4a	15.6±1.2a	20.4±4.8ab	6.7±0.7a	52.7±10.9a
FS	106.7±2.4a	17±1ab	1.3±0.6a	4.0±1.4b	2.5±0.1a	14.7±1.3a	19.7±2.6ab	6.5±1.3a	48.7±3.0a
DS	105.0±4.1a	19±2ab	1.3±0.2a	9.9±2.0ab	3.0±0.3a	14.5±3.5a	18.8±4.9ab	7.6±1.7a	55.1±6.5a
MS	105.0±4.1a	18±2ab	1.5±0.0a	11.3±5.6a	2.8±0.5a	16.0±1.5a	26.1±2.7a	7.8±0.3a	65.4±8.1a

Different letters in the same column indicate significant differences under different treatment (P<0.05). The same as below
同一列不同小写字母表示不同处理间差异显著（P<0.05）,下同

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2.2 不同生育时期Cd胁迫对水稻成熟期各部位Cd含量的影响

图1是不同生育时期Cd胁迫对水稻成熟期糙米Cd含量的影响。各处理下糙米Cd含量范围在0.17— 1.05 mg·kg^-1。除FS处理外,各处理下糙米Cd含量均显著低于CG处理（P<0.05）。FS处理下糙米Cd含量最高（1.05 mg·kg^-1）,分别为CG、TS、JS、BS、DS和MS处理下糙米Cd含量的1.08、6.34、3.38、2.01、2.75和1.84倍;其次是MS处理（0.57 mg·kg^-1）（除CG外）,显著高于TS、JS和DS处理;除CK外,TS处理下糙米Cd含量最低（0.17 mg·kg^-1）,与BS、FS、DS和MS处理均存在显著差异（P<0.05）。

图1

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图1不同生育时期Cd胁迫对水稻成熟期糙米Cd含量的影响

不同小写字母表示不同处理间差异显著（P<0.05）
Fig. 1Effects of Cd stress at different rice growth stages on Cd contents in brown rice at maturing stage

Different letters indicate significant differences under different treatments at P<0.05

表3为不同生育时期Cd胁迫对水稻成熟期根、茎、叶、穗和谷壳Cd含量的影响。可以看出,各处理下根Cd含量变化范围最大,为4.09—22.32 mg·kg^-1,大小顺序为CG>BS≈FS>TS≈JS≈DS≈MS,均高于CK（1.60 mg·kg^-1）。BS和FS处理下根Cd含量显著高于TS、JS、DS和MS处理（P<0.05）。除CG处理外,各处理茎、叶和穗Cd含量差异不显著（P>0.05）。各处理下谷壳Cd含量变化范围为0.27—1.04 mg·kg^-1,除CG处理外,FS处理下Cd含量最高（0.96 mg·kg^-1）,显著高于TS、JS、DS和MS处理;其次为BS处理（0.71 mg·kg^-1）,除CK外,DS和MS处理下谷壳Cd含量最低（0.27 mg·kg^-1）。

Table 3
表3
表3不同生育时期Cd胁迫对水稻成熟期根、茎、叶、穗和谷壳Cd含量的影响
Table 3Effects of Cd stress at different rice growth stages on Cd contents in root, stem, leaf, ear and husk at maturing stage (mg·kg^-1)

处理 Treatment	谷壳 Husk	穗 Ear	叶 Leaf	茎 Stem	根 Root
CK	0.10±0.03c	0.05±0.01b	0.02±0.01b	0.07±0.03b	1.60±0.09c
CG	1.04±0.34a	0.74±0.29a	0.99±0.07a	3.00±1.78a	22.32±4.99a
TS	0.31±0.05bc	0.27±0.08b	0.12±0.02b	0.23±0.04b	5.72±1.53c
JS	0.45±0.09bc	0.22±0.10b	0.08±0.02b	0.45±0.15b	5.02±0.78c
BS	0.71±0.18ab	0.52±0.18ab	0.11±0.05b	0.72±0.27b	12.89±0.97b
FS	0.96±0.23a	0.37±0.18ab	0.07±0.02b	0.60±0.27b	12.51±1.64b
DS	0.27±0.07c	0.36±0.14ab	0.08±0.02b	0.25±0.07b	4.53±0.94c
MS	0.27±0.06c	0.13±0.10b	0.08±0.03b	0.21±0.17b	4.09±2.05c

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2.3 不同生育时期Cd胁迫对水稻成熟期各部位Cd累积量的影响

不同生育时期Cd胁迫对水稻植株Cd累积量影响显著（表4）。各处理下水稻植株Cd总累积量为42.24—228.21 μg/株,大小顺序为CG>BS≈FS>TS≈JS≈DS≈MS,均高于CK（15.45 μg/株）。各处理下成熟期糙米Cd累积量为0.18—1.56 μg/株,除CG处理外,FS处理糙米Cd累积量最高（1.39 μg/株）,MS处理次之（0.84 μg/株）,TS处理最低（0.18 μg/株）。各处理下根Cd累积量变化范围为31.55—155.87 μg/株,BS和FS处理根Cd累积量较高（86.09和79.23 μg/株）,显著高于其他处理（P<0.05）。除CG处理外,BS处理谷壳Cd累积量最高,但与其他处理不存在显著差异;各处理下茎、叶和穗Cd累积量变化不显著（P>0.05）。

Table 4
表4
表4不同生育时期Cd胁迫对水稻成熟期各部位（根、茎、叶、穗、谷壳和糙米）Cd累积量的影响
Table 4Effects of Cd stress at different rice growth stages on Cd accumulation amounts in root, stem, leaf, ear, husk and brown rice at maturing stage (μg/plant)

处理 Treatment	糙米 Brown rice	谷壳 Husk	穗 Ear	叶 Leaf	茎 Stem	根 Root	植株 Rice plant
CK	0.11±0.02d	0.66±0.11b	0.10±0.05c	0.24±0.01b	1.64±0.60b	12.71±1.44c	15.45±2.12c
CG	1.56±0.24a	8.85±3.48a	1.76±0.33a	17.16±3.81a	43.02±20.56a	155.87±34.41a	228.21±55.88a
TS	0.18±0.03cd	1.72±0.29b	0.63±0.12bc	2.25±0.81b	4.20±0.71b	38.10±4.23c	47.08±3.38c
JS	0.24±0.03cd	1.92±1.20b	0.66±0.33bc	1.02±0.36b	8.25±1.83b	40.37±5.27c	52.47±6.81c
BS	0.75±0.28c	4.06±2.16b	1.14±0.23ab	1.69±0.65b	13.42±2.20b	86.09±2.36b	107.13±3.11b
FS	1.39±0.69ab	3.74±1.08b	0.90±0.43bc	0.98±0.30b	12.11±6.58b	79.23±5.21b	98.35±6.22b
DS	0.49±0.19cd	2.57±0.48b	1.06±0.36ab	1.17±0.53b	4.61±1.76b	32.77±1.23c	42.68±2.10c
MS	0.84±0.04bc	3.33±2.26b	0.32±0.17bc	1.22±0.40b	4.97±3.65b	31.55±15.30c	42.24±18.08c

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2.4 不同生育时期Cd累积对水稻成熟期糙米Cd累积的相对贡献

图2表述了水稻在不同生育时期Cd累积对成熟期糙米Cd累积的相对贡献率,其中灌浆期累积的Cd对糙米Cd累积相对贡献最大,其次是成熟期和孕穗期。不同生育时期累积的Cd对水稻糙米Cd累积的相对贡献大小顺序为灌浆期（39.3%）>成熟期（22.6%）>孕穗期（19.7%）>腊熟期（11.9%）>拔节期（4.2%）>分蘖期（2.4%）,说明水稻孕穗至灌浆阶段以及水稻在成熟期吸收累积的Cd是成熟期糙米中Cd的主要来源。

图2

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图2不同生育时期Cd累积对水稻成熟期糙米Cd累积的相对贡献率

Fig. 2Relative contribution of Cd accumulation in rice at different growth stages to Cd accumulation in brown rice at maturing stage (%)

3 讨论

3.1 不同生育时期Cd胁迫对水稻各部位Cd累积影响差异

水稻在不同生育时期吸收的Cd对成熟期各部位Cd累积量均产生一定影响（表4）,同时水稻各部位累积Cd的关键生育时期存在差异。除全生育时期Cd胁迫外,孕穗期和灌浆期Cd胁迫下,根Cd累积量显著高于其他生育时期Cd胁迫下的Cd累积量,分别为86.09 μg/株、79.23 μg/株。孕穗期是水稻生长发育的重要时期,生理活动旺盛,吸收各种营养元素的能力提高^[18];水稻在孕穗期形成发达的根系^[19],增大了根和营养液的接触面积,而根系作为水稻吸收养分和矿质元素的主要器官,对Cd的吸收自然也较多^[20]。孕穗期和灌浆期Cd胁迫下,水稻茎、谷壳和植株Cd累积量均较高^[21];糙米Cd累积量（0.75 μg/株、1.39 μg/株）也仅略低于全生育时期胁迫下糙米Cd累积量（1.56 μg/株）,说明孕穗期和灌浆期对水稻累积Cd十分关键^[22]。孕穗期是水稻谷壳进一步形成、完善的重要时期,水稻大部分营养物质提供给稻穗,所以该时期谷壳Cd累积较多^[7]。除全生育时期Cd胁迫外,分蘖期Cd胁迫下叶的Cd累积量最高。在水稻分蘖期,叶片对营养元素的需求量大,Cd能够随营养元素,通过主动运输和被动运输等方式被水稻吸收进入叶片并累积下来^[7,23-24]。各生育时期Cd胁迫下的根、茎、穗、谷壳、糙米Cd累积量总和分别为308.11、47.56、4.71、17.34、3.89 μg/株,均高于全生育时期Cd胁迫下根、茎、穗、谷壳、糙米Cd累积量（155.87、43.02、1.76、8.85、1.56 μg/株）（表4）。处于全生育时期Cd胁迫下的水稻,能通过合成应激物质（乙烯或蛋白）增强自身对Cd的耐性,此类物质能阻挡水稻根系吸收以及向茎叶中转运Cd,来降低水稻对Cd的吸收累积^[25,26,27]。这种植物适应Cd胁迫的耐性机制,导致全生育时期Cd胁迫下Cd累积量显著低于各生育时期Cd胁迫下的总和。

3.2 不同生育时期Cd胁迫对水稻成熟期糙米Cd累积相对贡献差异

本研究通过在水稻不同生育时期添加外源Cd来探究成熟期糙米Cd累积的关键生育时期。孕穗期、灌浆期、腊熟期和成熟期Cd胁迫下,成熟期糙米Cd含量均高于分蘖期和拔节期Cd胁迫下的糙米Cd含量,说明水稻在孕穗到成熟阶段吸收转运的Cd对糙米Cd累积的贡献比孕穗期前吸收转运的Cd要大（图1）。值得一提的是,灌浆期Cd胁迫下,成熟期糙米Cd含量最高（1.05 mg·kg^-1）,显著高于其他处理（P<0.05）,甚至高于全生育时期Cd胁迫下糙米的Cd含量（0.97 mg·kg^-1）,表明在水稻灌浆期,糙米累积Cd的能力较强^[22]。研究发现,在水稻灌浆期,土壤中的Cd被植物根系吸收进入水稻植株体内,能与木质部中大量有机酸和氨基酸结合形成复合物,随着茎的木质部蒸腾流输送到地上部位,直接转运至糙米中^[15,28]。另外,贮藏在水稻茎鞘中的淀粉和蔗糖等非结构性碳水化合物,以及叶光合作用产物被大量转运到籽粒胚乳中^[29],Cd也随着灌浆物质被转运至糙米。冯雪敏^[30]通过稳定性同位素示踪技术发现,拔节期、抽穗期和灌浆期Cd胁迫对水稻成熟期糙米Cd累积的贡献达到65%—75%,且灌浆期从根部吸收的Cd对成熟期糙米Cd累积贡献最大。本研究同样发现,水稻不同生育时期Cd累积对糙米Cd累积的贡献存在显著差异,与唐皓和李鹏等的研究结果一致^[31,32]。孕穗期、灌浆期和成熟期是糙米Cd累积关键时期,这3个时期Cd累积对糙米中Cd累积贡献较大,相对贡献率分别为19.7%、39.3%和22.6%,这与RODDA等^[15]的研究结果相近,水稻扬花期后根系吸收的Cd是糙米中Cd的主要来源。灌浆期是糙米Cd累积最重要的时期,主要是因为在该时期,水稻籽粒中蛋白质合成加剧^[33],重金属Cd能够被叶和茎节中的OsLCT1和OsNRAMP1等转运蛋白转运到籽粒中^[34],籽粒中的Cd与蛋白质结合而被固定^[35],因此几乎不向其他水稻部位转运而被累积在糙米中,这与彭鸥等^[13]的水培试验结果基本一致。本研究主要属于理论研究,与水稻的实际种植有很大差异。在后期的研究中,我们将应用水培试验的结果来进行水稻的土壤栽培试验,希望能够找到利用土壤调理剂（或钝化剂）控制土壤Cd向糙米转运最佳时机和最佳方法。

4 结论

不同生育时期Cd胁迫对水稻生长没有显著影响。在孕穗期和灌浆期,水稻根系吸收累积转运Cd的能力较强,这是水稻植株累积Cd的重要时期。水稻成熟期糙米中的Cd主要来源于孕穗期、灌浆期和成熟期营养物质运输的吸收、转运和累积。因此,孕穗期、灌浆期和成熟期是糙米Cd累积关键时期,对糙米Cd累积的相对贡献分别为19.7%、39.3%和22.6%。

The authors have declared that no competing interests exist.

作者已声明无竞争性利益关系。

参考文献原文顺序
文献年度倒序
文中引用次数倒序
被引期刊影响因子

[1]

环境保护部, 国土资源部. 全国土壤污染状况调查公报
中国环保产业, 2014,36(5):10-11.

DOI:10.11654/jaes.2017-1220 URL [本文引用: 1]

2014年4月17日,环境保护部和国土资源部发布了全国土壤污染状况调查公报。为全面认识和正确理解公报内容,环境保护部和国土资源部等相关负责人回答了记者提问。本刊将相关内容刊登如下。

Ministry of Environmental Protection, Ministry of Land and Resources. Bulletin of the national soil pollution survey.China's Environmental Protection Industry, 2014, 36(5):10-11. (in Chinese)

DOI:10.11654/jaes.2017-1220 URL [本文引用: 1]

2014年4月17日,环境保护部和国土资源部发布了全国土壤污染状况调查公报。为全面认识和正确理解公报内容,环境保护部和国土资源部等相关负责人回答了记者提问。本刊将相关内容刊登如下。

[2]

杨文弢, 周航, 邓贵友, 朱维, 吴玉俊, 邹紫今, 王艳, 廖柏寒 . 组配改良剂对污染稻田中铅、镉和砷生物有效性的影响
环境科学学报, 2016,36(1):257-263.

DOI:10.13671/j.hjkxxb.2015.0133 URL Magsci [本文引用: 1]

选取湖南某矿区重金属和砷复合污染稻田土,以盆栽实验研究了施用组配改良剂LMF(碳酸钙+偏高岭土+钙镁磷肥)对土壤中Pb、Cd和As的生物有效性和水稻糙米中Pb、Cd和As累积效应的影响.结果表明:施用LMF能显著增加供试土壤pH值、交换性盐基总量(TEB)和阳离子交换量(CEC),对盐基饱和度(BS)和有机质(OM)含量无显著影响.施用LMF能显著降低土壤中Pb、Cd的交换态和酸可提取态含量,以及降低Pb的TCLP提取态含量,对Cd的TCLP提取态含量无明显效果.LMF施用使土壤中As的交换态和TCLP提取态含量呈现先下降后上升的趋势,且均在施用量为2 g·kg-1时含量最低.随着LMF施用量的增加,水稻糙米中Pb、Cd的含量分别降低了8.44%~99.6%、27.5%~74.1%,而水稻糙米中As含量呈现出先下降后上升的趋势.除Cd的TCLP提取态和酸可提取态外,Pb、Cd和As的其它提取态含量与其在水稻糙米中的含量均呈现出显著正相关关系(p<0.05或p<0.01).

YANG W

, ZHOU

, DENG G

, ZHU

, WU Y

, ZOU Z

, WANG

, LIAO B

. Effects of combined amendment on bioavailability of Pb, Cd, and As in polluted paddy soil
Acta Scientiae Circumstantiae, 2016,36(1):257-263. (in Chinese)

DOI:10.13671/j.hjkxxb.2015.0133 URL Magsci [本文引用: 1]

CHANEY R

, REEVES P

, PHILIP P

, SIMMONS R

, WELCH R

, ANGLE J

. An improved understanding of soil Cd risk to humans and low cost methods to phytoextract Cd from contaminated soils to prevent soil Cd risks
Biometals, 2004,17(5):549-553.

DOI:10.1023/B:BIOM.0000045737.85738.cf URLPMID:15688862 [本文引用: 1]

We believe greater consideration should be given the agronomic and nutritional/bioavailability factors that influence risk from Cd-contaminated soils. We have argued that the ability of rice to accumulate soil Cd in grain while excluding Fe, Zn and Ca (even though the soil contains 100-times more Zn than Cd) was important in adverse effects of soil Cd is farm families in Asia. Further, polished rice grain is deficient in Fe, Zn and Ca for humans, which promotes Cd absorption into duodenal cells. New kinetic studies clarified that dietary Cd is absorbed into duodenum enterocytes; 109 Cd from a single meal remained in the duodenum for up to 16 days; part of the turnover pool 109 Cd moved to the liver and kidneys by the end of the 64-day `chase' period. Thus malnutrition induced by subsistence rice diets caused a higher absorption of dietary Cd and much higher potential risk from soil Cd than other crops. Because rice-induced Fe-Zn-Ca-malnutrition is so important in soil Cd risk, it seems evident that providing nutritional supplements to populations of exposed subsistence rice farmers could protect them against soil Cd during a period of soil remediation. In the long term, high Cd rice soils need to be remediated. Remediation by removal and replacement of contaminated soil is very expensive (on the order of $3 million/ha); while phytoextraction using the high Cd accumulating ecotypes of the Zn-Cd hyperaccumulator, Thlaspi caerulescens , should provide low cost soil Cd remediation.

[4]

张小敏, 张秀英, 钟太洋, 江洪 . 中国农田土壤重金属富集状况及其空间分布研究
环境科学, 2014,35(2):692-703.

URL [本文引用: 1]

在统计有关我国农田土壤重金属相关文献数据的基础上,探讨了我国农田土壤重金属Pb、Cd、Cu、Zn和Cr的空间富集现状.收集到有关土壤Pb、Cd、Cu、Zn和Cr含量的研究分别为173、138、156、139、140个.首先剔除异常值,然后利用剩余样本进行克里金插值,并统计各省地区重金属含量平均值.结果表明我国重金属空间分布具有明显的区域特征,西南地区土壤重金属含量较高,其他地区相对较低;与分省的土壤背景值相比较,农田土壤Pb和Cd的含量明显高于背景值.土壤Pb在云南省超出背景值最高,为背景值的1.91倍;Cd在辽宁省超出背景值最高,为23.02倍;Zn在云南省富集最为严重,是背景值的1.55倍,Cu最高的是广东省,达到背景值的2.92倍.

ZHANG X

, ZHANG X

, ZHONG T

, JIANG

. Spatial distribution and accumulation of heavy metal in arable land soil of China
Environmental Science, 2014,35(2):692-703. (in Chinese)

URL [本文引用: 1]

史静, 李正文, 龚伟群, 潘根兴 . 2种常规水稻Cd、Zn吸收与器官分配的生育期变化: 品种、土壤和Cd处理的影响
生态毒理学报, 2007,2(1):32-40.

DOI:10.3969/j.issn.1673-5897.2007.01.005 URL [本文引用: 1]

Soil-food crop-diet transfer has been considered as the dominant pathway of human exposure to Cd and the potential health risk. Rice（Oryza sativa L.），in particular, has been concerned as a food crop that significantly accumulates Cd in grains. A pot experiment of Cd and Zn uptake and portioning in plant organs during the whole growing period was conducted using consistently submerged condition. Two cultivars of non-hybrid rice, Suxiangjing 1（high Cd affinity cultivars）and 99-22（low Cd affinity cultivars），were grown in two paddy soils with contrasting chemical properties and soil total Cd and Zn contents. Cd was spiked at 0mg·kg-1 of soil（as the control）and 2mg·kg-1, respectively. Rice plants were harvested in different growth stages and the biomass and Cd and Zn contents, of different organs were determined. The results obtained were as follows：1）Uptake of Cd and Zn by the rice were affected by soil type, cultivars, and Cd spike, of which under a positive mutual interaction（high Cd affinity cultivars on the soil of high Cd availability）very high grain Cd and Cd/Zn ratio was observed due to strong uptake and high grain partitioning of Cd; 2）Cd uptake and organ partitioning by rice plant varied with the different growing stages. Significant uptake of Cd was observed in the tillering and ripening stages while that of Zn was in tillering, spiking and filling stages; Zn depletion with enhanced Cd uptake was aparent in the whole life period, especially under spiked Cd treatments；3）There existed significant differences in Cd and Zn partitioning in plant organs both between the growth stages of a single cultivars and between the cultivars in a single stage. Total Cd amount was in the order: roots > grains > shoots, and the total Zn was in an order: shoots > roots and grains. An intense translocation of plant Cd to grains happened even the ripening stage of both cultivars. Stronger Cd but weaker Zn transfer to grains by the high Cd affinity cultivars than the low one could be considered as a major plant factor controlling high Cd uptake and accumulation, and the high Cd/Zn ratio in rice grains.

SHI

, LI Z

, GONG W

, PAN G

. Uptake and partitioning of Cd and Zn by two non-hybrid rice cultivars in different growth stages: Effect of cultivars, soil type and Cd spike
Asian Journal of Ecotoxicology, 2007,2(1):32-40. (in Chinese)

DOI:10.3969/j.issn.1673-5897.2007.01.005 URL [本文引用: 1]

YONG F

, DOUG H

, DO S

, YUN W

. Absorption, translocation, and remobilization of cadmium supplied at different growth stages of rice
Journal of Crop Science & Biotechnology, 2010,13(2):113-119.

DOI:10.1007/s12892-010-0045-4 URL [本文引用: 2]

Cadmium (Cd) is absorbed by rice root and transferred into the other rice organs including grain. A solution-culture experiment was conducted to investigate the absorption and distribution of Cd supplied at different growth stages of rice. Two rice cultivars, a japonica ‘Chucheong’ and a tongil-type ‘Milyang23’ that exhibit high and low ability of Cd absorption by root and accumulation in grain were grown in culture solution and subjected to 2 ppm CdCl2 treatment for 2 weeks at four different growth stages: before panicle initiation stage (BPI), after panicle initiation stage (API), early ripening stage (ER), and mid-ripening stage (MR). Cd concentration and accumulation in rice organs were measured at harvest. The two rice cultivars accumulated two to three times greater amounts of Cd in grain in the two Cd treatments before heading (BPI and API treatments) than in the Cd treatment after heading (ER and MR treatment). The higher grain Cd accumulation in BPI and API treatments was not attributed to the higher Cd uptake but to the higher translocation from root to shoot and the higher redistribution from shoot to grain than ER and MR treatments These results imply that the remobilization of Cd through phloem during leaf senescence is the major process for Cd accumulation in rice grain rather than direct transport of absorbed Cd through the xylem-phloem transfer to grain. ‘Milyang23’ absorbed significantly smaller amount of Cd than ‘Chucheong’. However, ‘Milyang23’ accumulated more than a three times larger amount of Cd in grain compared to ‘Chucheong’ as the former exhibited the higher root-shoot translocation and shoot-grain remobilization as well. It indicates that the greater Cd translocation from root to shoot and subsequent higher Cd remobilization from shoot to grain, not the higher absorption ability, have led to the higher Cd accumulation and concentration in grain of ‘Milyang23’.

[7]

叶长城, 陈喆, 彭鸥, 周细红, 铁柏清, 刘孝利, 雷鸣, 魏祥东, 孙健 . 不同生育期Cd胁迫对水稻生长及镉累积的影响
环境科学学报, 2017,37(8):3201-3206.

DOI:10.13671/j.hjkxxb.2017.0077 URL [本文引用: 4]

采用水培试验方法,从水稻移栽至某特定生育期之间添加外源镉(Cd),通过递推减法,研究了湘晚籼13号水稻不同生育期Cd胁迫对其生长和不同部位中Cd含量的影响.结果表明,50 μg·L-1外源Cd胁迫不会影响水稻的正常生长发育,糙米中的Cd主要来源于水稻分蘖期吸收的Cd在后期的迁移、灌浆期吸收的Cd和成熟期吸收的Cd,这3个关键生育期对糙米中最终Cd含量的贡献率分别为36.4％、18.2％和16.4％.因此,与灌浆期和成熟期相比,在水稻分蘖期采用一些植物阻隔技术可能对水稻籽粒中Cd含量的削减更为重要.

YE C

, CHEN

, PENG

, ZHOU X

, TIE B

, LIU X

, LEI

, WEI X

, SUN

. Effects of cadmium stress on growth and cadmium accumulation in rice at different growth stages
Acta Scientiae Circumstantiae, 2017,37(8):3201-3206. (in Chinese)

DOI:10.13671/j.hjkxxb.2017.0077 URL [本文引用: 4]

GREGER

, LOFSTEDT

. Comparison of uptake and distribution of cadmium in different cultivars of bread and durum wheat
Crop Science, 2004,44(2):111-113.

DOI:10.2135/cropsci2004.5010 URL [本文引用: 1]

The intent of this study was to investigate whether high levels of cadmium (Cd) in the grains of high Cd-accumulating cultivars is caused by a nigh Cd uptake in the roots, a nigh translocation of Cd from roots to shoot, or a redistribution of Cd between the shoot and the grains. High and low accumulators, with respect to the grain accumulation of Cd, of spring and winter bread wheat (Triticum aestivum L.) and of durum wheat (T. durum Desf.) were selected from field studies. The selected cultivars were grown in nutrient solution containing 0.5 mM Cd in a climate chamber for (i) 19 d and (ii) until maturity. The concentration of Cd in roots, shoot, flag leaves, grains, and grain coats was measured by atomic absorption. The results indicated that there are differences among the cultivars in the ability to accumulate Cd in grains. The biggest differences were found among the durum wheat cultivars. Different Cd accumulation in grains was related to variations in the translocation from root to shoot and to the Cd concentration in shoot, flag leaf, and grain coats, but not to the uptake of Cd by roots.

[9]

KASHIWAGI

, SHINDOH

, HIROTSU

, ISHIMARU

. Evidence for separate translocation pathways in determining cadmium accumulation in grain and aerial plant parts in rice
BMC Plant Biology, 2009,9(1):8.

DOI:10.1186/1471-2229-9-8 URL [本文引用: 1]

[10]

张振兴, 纪雄辉, 谢运河, 官迪, 彭华, 朱坚, 田发祥 . 水稻不同生育期施用生石灰对稻米镉含量的影响
农业环境科学学报, 2016,35(10):1867-1872.

DOI:10.11654/jaes.2016-0432 URL [本文引用: 1]

为了深入探究镉污染稻田土壤施用生石灰降低稻米镉含量的过程机理,采用盆栽试验,分别在水稻插秧前、分蘖期、孕穗期、灌浆期进行生石灰施加处理,水稻成熟后采集植株样品和土壤样品进行相关指标测定。试验结果显示,在水稻不同生育期施加生石灰均可显著提高土壤pH值,降低土壤有效态镉及根系镉含量,同时显著降低糙米镉含量(P0.05)。分蘖期施加生石灰对糙米镉含量的降低程度最大,其含量比空白对照下降55.2%,显著低于其他处理。在分蘖期施加生石灰后发现,水稻茎秆中的钙含量最高,显著高于其他处理(P0.05),而其茎秆中的镉含量反而最低,显著低于其他处理(P0.05)。多变量主成分分析显示,茎秆钙含量与镉含量显著负相关(P0.05)。综上认为,在水稻分蘖期施用生石灰不仅可以降低土壤有效态镉含量,减少根系对镉的吸收积累,还可以提高水稻茎秆中的钙含量,进而抑制镉由根系向茎秆的转移,表明这两个过程的叠加效应可能是水稻分蘖期施用生石灰降低糙米镉含量的关键因素。

ZHANG Z

, JI X

, XIE Y

, GUAN

, PENG

, ZHU

, TIAN F

. Effects of quicklime application at different rice growing stage on the cadmium contents in rice grain
Journal of Agro-Environmental Science, 2016,35(10):1867-1872. (in Chinese)

DOI:10.11654/jaes.2016-0432 URL [本文引用: 1]

靳磊, 胡召华, 纪雄辉, 魏维, 谢运河 . 不同时期喷施Zn肥抑制水稻Cd吸收转运的效果
湖南农业科学, 2017,8(1):37-40.

DOI:10.16498/j.cnki.hnnykx.2017.008.010 URL [本文引用: 1]

选择湖南典型镉（Cd）污染稻田，分别在苗期、分蘖初期、分蘖盛期和孕穗期喷施锌（Zn）肥，研究Zn对水稻Cd吸收转运的影响。结果表明：喷施Zn肥可显著提高水稻地上部的Zn含量，并显著抑制水稻对Cd的吸收，分蘖盛期和孕穗期喷施Zn肥，稻米中Cd含量分别降低了45.85%（P<0.05）和47.52%（P<0.05）。试验结果还表明，水稻米、茎、叶间Zn-Cd交互作用显著，施Zn可显著抑制水稻对Cd的吸收转运，米Cd含量主要由茎Cd含量决定，但受Zn-Cd拮抗作用的调控。

JIN

, HU S

, JI X

, WEI

, XIE Y

. Effects of Zinc foliar application at different growth stages on cadmium absorption and transport in rice
Hunan Agricultural Sciences, 2017,8(1):37-40. (in Chinese)

DOI:10.16498/j.cnki.hnnykx.2017.008.010 URL [本文引用: 1]

ZHOU

, ZHU

, YANG W

, GU J

, GAO Z

, CHEN L

, DU W

, ZHANG

, PENG P

, LIAO B

. Cadmium uptake, accumulation, and remobilization in iron plaque and rice tissues at different growth stages
Ecotoxicology & Environmental Safety, 2018,152:91-97

DOI:10.1016/j.ecoenv.2018.01.031 URLPMID:29407786 [本文引用: 1]

Rice consumption is considered the main source of human dietary Cd intake in Southeast Asia. This study aimed to investigate Cd uptake, accumulation, and remobilization in iron plaque and rice ( Oryza sativa L. cv. ‘Xiangwanxian 12′) tissues at different growth stages. A pot experiment was performed in two Cd-contaminated paddy soils. Cd concentrations in iron plaque and rice tissues at five different growth stages (tillering, booting, milky, dough, and maturing) were measured. Cd concentrations in iron plaque and rice tissues (roots, stems, leaves, spikelet, husks, and brown rice) varied with growth stage. Cd accumulation in rice plants increased with extending growth in both soils, reaching 15.3 and 35.402μg/pot, respectively, at the maturing stage. The amounts of Cd in brown rice increased from the milky to maturing stages, with the greatest percentage uptake during the maturing stage. Cd amount in iron plaque significantly affected the uptake and accumulation of Cd in roots and aerial parts of rice plants. Accumulated Cd in leaves was remobilized and transported during the booting to maturing stages, and the contributions of Cd transportation from leaves to brown rice were 30.0% and 22.5% in the two soils, respectively. A large amount of Cd accumulated in brown rice during the maturing stage. The transportation of remobilized Cd from leaves was also important for the accumulation of Cd in brown rice.

[13]

彭鸥, 铁柏清, 叶长城, 张淼, 刘孝利, 魏祥东, 孙健 . 稻米镉关键积累时期研究
农业资源与环境学报, 2017,34(3):272-279.

DOI:10.13254/j.jare.2017.0035 URL [本文引用: 3]

探明水稻不同生育期镉积累特征对于稻米安全生产具有重要的科学价值与现实意义,本研究采用水培试验方法,于水稻不同生育期分阶段添加外源镉,分析水稻不同生育期低浓度镉（50μg·L~（-1））胁迫下水稻每个生育期、主要部位镉含量及其内在关联。抽穗期阶段镉胁迫对水稻籽粒镉积累速率影响最为明显,最高达到3.41μg·蔸~（-1）·d~（-1）。孕穗期和抽穗期阶段镉胁迫对稻米镉积累量贡献率较高,中嘉早17号分别为40.51%、31.66%,湘晚籼13号分别为37.97%、35.46%。研究表明,孕穗期、抽穗期是控制镉米形成的关键时期,本结果可为镉超标稻田的安全生产及阻控米镉积累提供支持和科学指导。

PENG

, TIE B

, YE C

, ZHANG

, LIU X

, WEI X

, SUN

. The key period of cadmium accumulation in rice
Journal of Agricultural Resources and Environment, 2017,34(3):272-279. (in Chinese)

DOI:10.13254/j.jare.2017.0035 URL [本文引用: 3]

薛应龙 . 植物生理学实验手册. 上海: 上海科学技术出版社, 1985.

[本文引用: 1]

XUE Y

. Experimental Manual of Plant Physiology. Shanghai: Shanghai Scientific & Technical Publishers, 1985. ( in Chinese)

[本文引用: 1]

[15]

RODDA M

, LI

, REID R

. The timing of grain Cd accumulation in rice plants: The relative importance of remobilisation within the plant and root Cd uptake post-flowering
Plant & Soil, 2011,347(1/2):105-114.

DOI:10.1007/s11104-011-0829-4 URL [本文引用: 3]

The pathways by which Cd is accumulated in rice grain are not well understood, in particular the components attributable to direct transfer from the root, and to remobilisation of Cd previously accumulated in other plant parts. In order to observe the timing of Cd accumulation in rice plants and determine the major period for accumulation of Cd which can be translocated to the grain, Cd was supplied to the roots of rice plants grown under static hydroponic conditions at a non-toxic, environmentally relevant concentration (50 nM), according to three different timing regimes: (1) Pre-flowering Cd, (2) Post-flowering Cd, or (3) Continuous Cd. The rate of accumulation of Cd in the developing grain was monitored by harvesting immature rice panicles at four time points prior to a final harvest. Nearly all grain Cd was accumulated within 16 days of anthesis and the contribution of post-flowering Cd uptake was evident from 7 days after flowering. It was estimated that 60% of the final grain Cd content was remobilised from that accumulated by the plant prior to flowering and the other 40% came from uptake during grain maturation. This study shows that Cd uptake from the root to the grain in rice is indeed possible post-flowering and it is an important source of grain Cd.

[16]

胡莹, 黄益宗, 段桂兰, 刘云霞 . 镉对不同生态型水稻的毒性及其在水稻体内迁移转运
生态毒理学报, 2012,7(6):664-670.

[本文引用: 1]

, HUANG Y

, DUAN G

, LIU Y

. Cadmium toxicity and its translocation in two ecotype rice cultivars
Asian Journal of Ecotoxicology, 2012,7(6):664-670. (in Chinese)

[本文引用: 1]

[17]

胡莹, 黄益宗, 黄艳超, 刘云霞 . 不同生育期水稻根表铁膜的形成及其对水稻吸收和转运Cd的影响
农业环境科学学报, 2013,32(3):432-437.

DOI:10.11654/jaes.2013.03.004 URL [本文引用: 1]

采用盆栽试验,研究不同生育期水稻根表铁膜的形成及其对水稻吸收和转运Cd的影响。结果表明,水稻根表铁膜的形成受到不同品种和不同生育期影响。随着生育期的延长,两种水稻（YD6和NK57）根表铁膜形成量均呈下降趋势。与分蘖期相比,YD6和NK57根表铁膜量孕穗期分别减少82.9%和44.4%,成熟期分别减少85.2%和82.52%。两种水稻根系和茎叶Cd含量随着水稻生育期的延长而增加。YD6籽粒Cd含量显著高于NK57。Cd在水稻植株的富集系数和分配比率随着不同品种和生育期产生较大变化。YD6品种从根表铁膜和根系向籽粒转运Cd的能力显著大于NK57。水稻成熟期,根表铁膜量与茎叶和籽粒Cd含量呈极显著的负相关（P〈0.01）,说明根表铁膜形成可抑制Cd 向水稻地上部转运。研究结果暗示可通过不同生育期的管理调节水稻根表铁膜的形成,减少Cd向稻谷中转运,从而降低Cd对人体健康的危害。

, HUANG Y

, LIU Y

. Formation of iron plaque on root surface and its effect on Cd uptake and translocation by rice (Oryza sativa L.) at different growth stages
Journal of Agro-Environmental Science, 2013,32(3):432-437. (in Chinese)

DOI:10.11654/jaes.2013.03.004 URL [本文引用: 1]

LIU H

, ZHANG J

, CHRISTIE

, ZHANG F

. Influence of external zinc and phosphorus supply on Cd uptake by rice (Oryza sativa L.) seedlings with root surface iron plaque
Plant & Soil, 2007,300(1/2):105-115.

[本文引用: 1]

[19]

史锟, 张福锁, 刘学军, 张旭东 . 不同时期施铁对水稻根表铁胶膜中铁镉含量及根系含镉量的影响
农业环境科学学报, 2004,23(1):6-12.

DOI:10.3321/j.issn:1672-2043.2004.01.002 URL [本文引用: 1]

采用镉污染土壤-河砂-营养液联合培养的方法,研究了不同时期施铁对水稻根表铁胶膜中铁、镉含量的影响。选择水稻的分蘖、拔节、孕穗和灌浆4个时期,进行分期和各生育时期都施加铁的处理,在每个处理时期,设4个亚铁(Fe2+)水平分别为0、30、50和70mg·L-1,研究根表施铁浓度与水稻根表铁胶膜数量和吸附镉量之间的关系。结果表明,生长过程中取样测定的水稻根表铁胶膜铁含量,除个别处理外,都表现为施加铁的根表铁胶膜铁含量高于未施加铁的根表铁胶膜铁含量,尤其是孕穗期, 随着施铁量的增加根表铁胶膜铁含量增加。成熟时测定,灌浆期处理的水稻根表铁胶膜铁的含量变化比较大,分蘖期和拔节期变化比较小。各生育时期都处理的

SHI

, ZHANG F

, LIU X

, ZHANG X

. Effects of different periods applied Fe ²+ and concentrations on Fe and Cd contents in iron plaque on rice root
Journal of Agro-Environmental Science, 2004,23(1):6-12. (in Chinese)

DOI:10.3321/j.issn:1672-2043.2004.01.002 URL [本文引用: 1]

辜娇峰 . 组配改良剂对稻田镉砷复合污染的调控效果及机制研究[D]. 长沙: 中南林业科技大学, 2017.

[本文引用: 1]

GU J

. Mechanisms and effects of combined amendment regulating paddy soil complexly contaminated with cadmium and arsenic[D]. Changsha: Central South University of Forestry and Technology, 2017. (in Chinese)

[本文引用: 1]

[21]

陈宝玉, 王洪君, 曹铁华, 梁烜赫, 杨建, 任军 . 不同磷肥浓度下土壤-水稻系统重金属的时空累积特征
农业环境科学学报, 2010,29(12):2274-2280.

URL [本文引用: 1]

针对磷肥是水稻田重金属污染的主要来源,采用田间试验与室内分析相结合的研究方法,在吉林省九台市饮马河老稻田区,开展5种磷肥浓度处理对土壤-水稻系统重金属Cd和Pb的时空累积、分布特征研究。结果显示,磷肥中Cd和Pb含量高于土壤背景值,但没有超出国家土壤环境质量(二级)限定范围。磷肥施入土壤后,部分滞留在土壤里,少量向地上部分迁移,水稻根部累积重金属含量较高。随水稻生育期的变化,成熟期重金属在根、叶和籽实累积量最大,茎的重金属累积量在孕穗期达到最大。重金属Cd 在水稻各器官的迁移能力为根籽粒叶茎,Pb的迁移能力为根叶籽粒茎,Cd在水稻地上部分的迁移能力要明显强于Pb。磷肥施用量和重金属含量的关系可用线性回归方程来模拟,相关性检验显示重金属累积量与磷肥施用浓度均达到显著相关(P0.01)(除根中Cd含量与磷肥浓度达到0.05显著水平),说明水稻栽培生产中过量使用磷肥,能产生重金属对土壤和稻米的污染,进而导致重金属对人畜健康的潜在威胁。

CHEN B

, WANG H

, CAO T

, LIANG X

, YANG

, REN

. Spatio-temporal characteristics of heavy metal accumulation in soil-rice cropping system under different phosphate fertilizer concentrations
Journal of Agro-Environmental Science, 2010,29(12):2274-2280. (in Chinese)

URL [本文引用: 1]

李冰, 王昌全, 李枝, 李仕贵 . Cd胁迫下杂交水稻对Cd的吸收及其动态变化
生态环境学报, 2014,23(2):312-316.

DOI:10.3969/j.issn.1674-5906.2014.02.021 URL [本文引用: 2]

镉(Cd)是非必需的有毒元素,是农业环境和农产品的重要污染物,易被水稻吸收并在籽粒中积累。不同水稻品种拥有不同的独特基因,导致水稻籽粒吸收积累Cd的能力存在一定的差异。因此,开展不同水稻品种耐Cd特性及其不同生育期的吸收转运效率研究具有重要意义。本文采用水培试验,研究了两个水稻(Oryza sativa L.)品种:D83A/R527(低吸收累积Cd)和辐优838(高吸收累积Cd)在不同质量浓度Cd胁迫下籽粒Cd质量分数及不同生育时期水稻根、茎、叶内Cd的吸收积累量及其动态变化特点。结果表明,两种水稻品种在Cd胁迫下籽粒Cd积累量差异显著,辐优838在1.0 mg·L-1 Cd质量浓度胁迫下籽粒Cd质量分数就已超过国家食品卫生标准;在1.0~3.0 mg·L-1 Cd质量浓度胁迫下,D83A/R527籽粒内Cd质量分数仅为辐优838的50~60%。随着Cd处理浓度增加和生育时期推进,两种水稻各部位Cd吸收量均表现为逐渐增加,其增加幅度总体表现为:辐优838D83A/R527;不同部位中,根的积累效应最强,叶片吸收积累能力最低,辐优838茎、叶吸收积累效率分别是D83A/R527的1.5~2.0倍左右。在1.0~3.0mg·L-1 Cd胁迫下,水稻Cd积累差异较为显著的时期为灌浆期,辐优838的根系向茎、叶的转移效率大于D83A/R527,且D83A/R527主要表现为由根系向茎Cd转移效率较高,叶片Cd积累相对较少。灌浆期是水稻籽粒干物质积累的重要时期,也是吸收累积Cd的重要时期,这为筛选低吸收积累水稻品种和调控Cd在水稻籽粒中的吸收累积奠定了重要理论基础。

, WANG C

, LI

, LI S

. Absorption of Cd by hybrid rice under the Cd stress and its dynamic change
Ecology and Environmental Sciences, 2014,23(2):312-316. (in Chinese)

DOI:10.3969/j.issn.1674-5906.2014.02.021 URL [本文引用: 2]

莫争, 王春霞, 陈琴, 王海, 薛传金, 王子健 . 重金属Cu, Pb, Zn, Cr, Cd在水稻植株中的富集和分布
环境化学, 2002,21(2):110-116.

DOI:10.3321/j.issn:0254-6108.2002.02.002 URL [本文引用: 1]

研究了外源可溶性重金属进入水稻土环境后,在水稻植株中的迁移、在水稻植株不同部位的分布及其分布随时间的变化.在水稻生长季节,重金属在水稻植株中迁移能力的大小依次为:Cd,Cr＞Zn,Cu＞Pb.重金属在水稻植株不同部位的积累分布是: 根部＞根基茎＞主茎＞穗＞籽实＞叶部.水稻分蘖期重金属在根部、茎干部和叶片的积累量达到最大,随着时间的延长,在根部积累的重金属愈来愈少;在茎干部积累的重金属在拔节期降至最小,随后含量又稍微上升;叶片上的重金属含量在拔节期迅速下降,随后趋于稳定.

, WANG C

, CHEN

, WANG

, XUE C

, WANG Z

. Distribution and enrichment of heavy metals of Cu, Pb, Zn, Cr and Cd in paddy plant
Environmental Chemistry, 2002,21(2):110-116. (in Chinese)

DOI:10.3321/j.issn:0254-6108.2002.02.002 URL [本文引用: 1]

张路, 张锡洲, 李廷轩, 余海英, 戢林 . Cd胁迫对水稻亲本材料Cd吸收分配的影响
农业环境科学学报, 2014,33(12):2288-2295.

DOI:10.11654/jaes.2014.12.002 URL [本文引用: 1]

采用土培试验,以前期筛选出的水稻Cd安全亲本材料D62B为试验材料,以普通材料Luhui17为对照,研究不同生育期水稻Cd安全亲本材料在1、4、16 mg·kg-1Cd处理浓度下对Cd的吸收、分配及转运特征。结果表明:(1)在不同Cd处理浓度下,水稻Cd安全亲本材料D62B生长受到了一定程度的抑制,且随Cd处理浓度的提高生物量均显著降低。当Cd处理浓度为16 mg·kg-1时,D62B在分蘖期、抽穗期和成熟期的生物量分别较1 mg·kg-1Cd处理降低了52.05%、43.06%和32.34%。(2)D62B地上部Cd含量和转移系数在不同生育期均显著低于Luhui17,成熟期谷壳、糙米Cd含量也较低。当Cd处理浓度为1 mg·kg-1和4 mg·kg-1时,D62B的糙米Cd含量均低于食品安全国家标准0.2 mg·kg-1,表现出Cd安全亲本材料的"安全性"。(3)随Cd处理浓度的提高,D62B对Cd的吸收速率显著增加,且在分蘖期其吸收速率达到最大。在各处理下,D62B对Cd的吸收速率与Luhui17差异不显著。但D62B对Cd的转运速率在4 mg·kg-1和16 mg·kg-1Cd处理下则显著低于Luhui17,成熟期差异达到最大,分别为Luhui17的46.52%和66.68%。(4)D62B地上部Cd的亚细胞分布表现为细胞壁>可溶部分>细胞器,Luhui17为可溶部分>细胞壁>细胞器,地下部则均表现为可溶部分>细胞壁>细胞器。随Cd处理浓度的增加,Luhui17地下部细胞壁的分配比例显著降低,在16 mg·kg-1Cd处理浓度下,Luhui17细胞壁的分配比例显著低于D62B。综上所述,最终表现出D62B具有籽粒Cd低积累的特点,可为培育Cd安全水稻品种提供优良的种质资源。

ZHANG

, ZHANG X

, LI T

, YU H

, JI

. Effects of cadmium stress on uptake and distribution of cadmium in different rice varieties
Journal of Agro-Environmental Science, 2014,33(12):2288-2295. (in Chinese)

DOI:10.11654/jaes.2014.12.002 URL [本文引用: 1]

荆红梅, 郑海雷, 赵中秋, 张春光 . 植物对镉胁迫响应的研究进展
生态学报, 2001,21(12):2125-2130.

DOI:10.3321/j.issn:1000-0933.2001.12.022 URL Magsci [本文引用: 1]

总结了近年来植物对一重要环境污染物镉的反应研究报道。探讨了镉对植物的各种毒性效应 ,并论述植物对镉胁迫采取的相应防御机制 ,如络合 ( PC、MT)、应激 (应激乙烯、应激蛋白 ) ,及额外防御机制 ,如细胞壁固定化、原生质膜排除、区域化、过氧化物酶等。

JIN H

, ZHENG H

, ZHAO Z

, ZHANG C

. Progresses of plants response to cadmium
Acta Ecologica Sinica, 2001,21(12):2125-2130. (in Chinese)

DOI:10.3321/j.issn:1000-0933.2001.12.022 URL Magsci [本文引用: 1]

总结了近年来植物对一重要环境污染物镉的反应研究报道。探讨了镉对植物的各种毒性效应 ,并论述植物对镉胁迫采取的相应防御机制 ,如络合 ( PC、MT)、应激 (应激乙烯、应激蛋白 ) ,及额外防御机制 ,如细胞壁固定化、原生质膜排除、区域化、过氧化物酶等。

[26]

张军, 束文圣 . 植物对重金属镉的耐受机制
植物生理与分子生物学学报, 2006,32(1):1-8.

DOI:10.3321/j.issn:1671-3877.2006.01.001 URL [本文引用: 1]

镉离子(Cd2+)具有强植物毒性,抑制植物生长,甚至使植物死亡。由于长期的环境选择和适应进化,植物发展出耐受机制,可减轻或避免Cd2+的毒害。硫转运蛋白、硫还原相关酶类以及半胱氨酸、谷胱甘肽和植物螯合肽合成基因的表达受Cd2+调控。同时这些基因的过表达也能提高植物对Cd2+的耐性。植物抗氧化系统对Cd2+胁迫诱发的活性氧的清除作用,具转运Cd2+活性的质膜转运蛋白促进Cd2+经共质体途径向木质部运输、装载,而后随蒸腾流向地上部迁移,具转运Cd2+活性的液泡膜转运蛋白促进Cd2+进入液泡的隔离作用,都在植物对Cd2+的耐性中起作用。

ZHANG

, SHU W

. Mechanisms of heavy metal cadmium tolerance in plants
Journal of Plant Physiology and Molecular Biology, 2006,32(1):1-8. (in Chinese)

DOI:10.3321/j.issn:1671-3877.2006.01.001 URL [本文引用: 1]

陈爱葵, 王茂意, 刘晓海, 曾小龙 . 水稻对重金属镉的吸收及耐性机理研究进展
生态科学, 2013,32(4):514-522.

URL Magsci [本文引用: 1]

Cd是一种不能降解、广泛存在于环境中的金属污染物,是植物体非必需元素、环境中生物毒性最强的重金属元素之一,主要来源于矿山开采、火力发电、机械加工,汽车尾气排放以及磷肥生产等。Cd可通过水稻根部进入机体,向地上部分迁移并蓄积,严重影响水稻正常生长, 并引起稻米Cd污染,通过食物链危害人类健康。从水稻Cd吸收影响因素及Cd在水稻中的吸收、运输和积累机理理等方面对水稻Cd污染研究现状进行综述,系统阐述了土壤pH、Eh、离子浓度等条件对水稻Cd吸收的影响,同时讨论了水稻对Cd胁迫的耐性机理及其分子机制。并指出存在的问题和研究方向。

CHEN A

, WANG M

, LIU X

, ZENG X

. Research progress on the effect of cadmium on rice and its absorption and tolerance mechanisms
Ecological Science, 2013,32(4):514-522. (in Chinese)

URL Magsci [本文引用: 1]

叶瑶瑶, 王飞娟, 石晓柳, 王高阳, 俞姣, 朱诚 . Cd在水稻籽粒中的积累及运输机制
园艺与种苗, 2012,11(1):58-61.

DOI:10.3969/j.issn.2095-0896.2012.11.019 URL [本文引用: 1]

Cd是毒性最大的重金属之一，在环境中的活性与在土壤一植物系统中的迁移能力都很强植物能积累较高浓度的Cd，并通过食物链进入人体引起人体的疾病.综述了Cd在水稻中的积累及运输机制的研究进展，包括根的吸收、木质部调节向上运输及韧皮部调节向籽粒中转运等方面

YE Y

, WANG F

, SHI X

, WANG G

, YU

, ZHU

. Mechanisms of Cd accumulation and transportation in rice grain
Horticulture & Seed, 2012,11(1):58-61. (in Chinese)

DOI:10.3969/j.issn.2095-0896.2012.11.019 URL [本文引用: 1]

Cd是毒性最大的重金属之一，在环境中的活性与在土壤一植物系统中的迁移能力都很强植物能积累较高浓度的Cd，并通过食物链进入人体引起人体的疾病.综述了Cd在水稻中的积累及运输机制的研究进展，包括根的吸收、木质部调节向上运输及韧皮部调节向籽粒中转运等方面

[29]

潘俊峰, 王博, 崔克辉, 黄见良, 聂立孝 . 氮肥对水稻节间和叶鞘非结构性碳水化合物积累转运特征的影响
中国水稻科学, 2016,30(3):273-282.

DOI:10.16819/j.1001-7216.2016.5128 URL Magsci [本文引用: 1]

以两优培九和扬稻6号为材料进行盆栽试验，研究低氮（N1）和高氮（N2）处理下水稻主茎上部3个节间和叶鞘非结构性碳水化合物（NSC）的积累转运特征及对氮肥用量的响应。结果表明：1)与N2处理相比，N1处理总体上显著促进灌浆早期两优培九倒2、倒3节间和叶鞘NSC的转运，对扬稻6号的影响差异不明显；N1处理显著增加了扬稻6号上部3个节收稿日期: 20150819；  修改稿收到日期: 20151229。基金项目: 国家自然科学基金资助项目（31371548）; 国家科技支撑计划资助项目（2013BAD07B10）。间及叶鞘和两优培九倒3节间及叶鞘NSC表观转运量，也增加了两品种上部3个节间及叶鞘的NSC（总）表观贡献率。2) 两个氮肥处理下，供试品种的叶鞘（两优培九倒3叶鞘除外）NSC转运量和表观贡献率大于节间。3)两优培九倒2、倒3节间及叶鞘NSC表观转运量和贡献率、上部3节间及叶鞘的NSC总转运量与总表观贡献率在两个氮肥处理下均高于扬稻6号。4)N1处理下，两优培九和扬稻6号倒2、倒3节间及叶鞘的转运量分别占总转运量的92%和75%，贡献率分别占91%和76%；而N2处理下两优培九倒2、倒3节间及叶鞘的转运量占90%，扬稻6号倒2、倒3节间则无输出。本研究表明水稻上部3个节间和叶鞘的NSC (总)转运量品种间存在差异，并受施氮量和节/叶位的影响。在水稻高产和减氮栽培中，通过选用适宜品种和优化氮肥管理，增加花前茎鞘NSC积累和花后NSC再分配，对提高水稻产量潜力和氮效率，特别是对花后逆境和减氮条件下产量稳定具有重要意义。

PAN J

, WANG

, CUI K

, HUANG J

, NIE L

. Effects of nitrogen application on accumulation and translocation of non- structural carbohydrates in internodes and sheaths of rice
Chinese Journal of Rice Science, 2016,30(3):273-282. (in Chinese)

DOI:10.16819/j.1001-7216.2016.5128 URL Magsci [本文引用: 1]

冯雪敏 . 水稻富集镉砷的关键部位、生育时期及相关元素的研究[D]. 北京: 中国农业科学院, 2017.

[本文引用: 1]

FENG X

. The key parts, important growth stages and related elements in Cd/As accumulation of rice[D]. Beijing: Chinese Academy of Agricultural Sciences, 2017. ( in Chinese)

[本文引用: 1]

[31]

唐皓, 李廷轩, 张锡洲, 余海英, 陈光登 . 水稻镉高积累材料不同生育期镉积累变化特征研究
农业环境科学学报, 2015,34(3):471-477.

[本文引用: 1]

TANG

, LI T

, ZHANG X

, YU H

, CHEN G

. Cadmium accumulation in high cadmium-accumulating rice cultivars at different growth stages
Journal of Agro-Environmental Science, 2015,34(3):471-477. (in Chinese)

[本文引用: 1]

[32]

李鹏, 葛滢, 吴龙华, 沈丽波, 谭维娜, 骆永明 . 两种籽粒镉含量不同水稻的镉吸收转运及其生理效应差异初探
中国水稻科学, 2011,25(3):291-296.

DOI:10.3969/j.issn.1001-7216.2011.03.010 URL Magsci [本文引用: 1]

以籽粒镉(Cd)含量不同的两个水稻品种为材料，采用水培和盆栽试验，研究了水稻不同生育期Cd吸收转运、生理效应对籽粒Cd浓度的影响。盆栽试验结果表明，在Cd含量为1.57 mg/kg的土壤中，中香1号（A16，低Cd品种）和IR656103824263（A54，高Cd品种）糙米中Cd含量分别为0.88和0.31 mg/kg。水培和土培试验均显示品种A16对Cd的吸收转运在苗期强于A54，但在苗期之后，A54吸收转运Cd的强度高于A16。比较不同生育期两个品种单株Cd累积量，发现苗期至拔节期的增幅最大。水稻非蛋白巯基（NPT）含量不仅与Cd胁迫程度密切相关，也在一定程度上制约着Cd从根部向地上部的转运，从而对水稻籽粒Cd含量产生影响。从各生育期A16和A54地上部和根中的Cd和NPT含量可以推断，水稻籽粒Cd含量的差异很大程度上受到根部吸收和向地上部转运的制约。水稻苗期和其他生育期Cd吸收转运特点不同的原因可能包括根系Cd滞留能力及根际土壤性状的差异。

, GE

, WU L

, SHEN L

, TAN W

, LUO Y

. Uptake and translocation of cadmium and its physiological effects in two rice cultivars differed in grain cadmium concentration
Chinese Journal of Rice Science, 2011,25(3):291-296. (in Chinese)

DOI:10.3969/j.issn.1001-7216.2011.03.010 URL Magsci [本文引用: 1]

梁成刚, 陈利平, 汪燕, 刘佳, 许光利, 李天 . 高温对水稻灌浆期籽粒氮代谢关键酶活性及蛋白质含量的影响
中国水稻科学, 2010,24(4):398-402.

DOI:10.3969/j.issn.1001-7216.2010.04.011 URL Magsci [本文引用: 1]

选用粳稻品种越光与籼稻品种IR72为材料，研究了高温对水稻灌浆期籽粒谷氨酰胺合成酶（GS）、谷氨酸合酶（GOGAT）、谷氨酸草酰乙酸转氨酶（GOT）、谷氨酸丙酮酸转氨酶（GPT）的活性及蛋白质与氨基酸含量的影响。结果表明，灌浆期高温下水稻籽粒GOGAT、GOT与GPT活性显著或极显著升高，但籽粒GS活性显著或极显著降低；籽粒蛋白质及氨基酸各组分含量极显著增加。高温下籽粒GS活性显著降低并未影响籽粒蛋白质的合成，认为籽粒GS不是限制水稻蛋白质合成的关键酶。

LIANG C

, CHEN L

, WANG

, LIU

, XU G

, LI

. Effects of high temperature on key enzyme activities of nitrogen metabolism and protein content during rice grain filling
Chinese Journal of Rice Science, 2010,24(4):398-402. (in Chinese)

DOI:10.3969/j.issn.1001-7216.2010.04.011 URL Magsci [本文引用: 1]

URAGUCHI

, KAMIYA

, SAKAMOTO

, KASAI

, SATO

, NAGAMURA

, YOSHIDA

, KYOZUKA

, ISHIKAWA

, FUJIWARA

. Low-affinity cation transporter (OsLCT1) regulates cadmium transport into rice grains
Proceedings of the National Academy of Science of the USA, 2011,108(52):20959-20964.

DOI:10.1073/pnas.1116531109 URLPMID:22160725 [本文引用: 1]

Accumulation of cadmium (Cd) in rice (Oryza sativa L.) grains poses a potential health problem, especially in Asia. Most Cd in rice grains accumulates through phloem transport, but the molecular mechanism of this transport has not been revealed. In this study, we identified a rice Cd transporter, OsLCT1, involved in Cd transport to the grains. OsLCT1-GFP was localized at the plasma membrane in plant cells, and OsLCT1 showed Cd efflux activity in yeast. In rice plants, strong OsLCT1 expression was observed in leaf blades and nodes during the reproductive stage. In the uppermost node, OsLCT1 transcripts were detected around large vascular bundles and in diffuse vascular bundles. RNAi-mediated knockdown of OsLCT1 did not affect xylem-mediated Cd transport but reduced phloem-mediated Cd transport. The knockdown plants of OsLCT1 accumulated approximately half as much Cd in the grains as did the control plants. The content of other metals in rice grains and plant growth were not negatively affected by OsLCT1 suppression. These results suggest that OsLCT1 functions at the nodes in Cd transport into grains and that in a standard japonica cultivar, the regulation of OsLCT1 enables the generation of "low-Cd rice" without negative effects on agronomical traits. These findings identify a transporter gene for phloem Cd transport in plants.

[35]

杨居荣, 何孟常, 查燕, 刘虹, 张平 . 稻、麦籽实中Cd的结合形态
中国环境科学, 2000,20(5):404-408.

DOI:10.3321/j.issn:1000-6923.2000.05.006 URL [本文引用: 1]

对污染区稻、麦籽实中Cd的存在形态进行了分析,结果表明,在籽实主要营养成分以蛋白质中结合Cd的比例最高;根据籽实中蛋白质在各种溶剂中溶解度不同,区分清蛋白、醇溶谷蛋白、球蛋白及谷蛋白,对其中Cd的分析表明,以球蛋白和谷蛋白结合Cd的比例为高;通过SephadexG75柱层析对Tris-HCl可溶性组分的分离分析表明,Cd-蛋白质结合体的表观分子量为54.5×103和5.5×103,并对其氨基酸组成进行了分析.

YANG J

, HE M

, CHA

, LIU

, ZHANG

. Binding forms of Cd in the rice and wheat seeds
China Environmental Science, 2000,20(5):404-408. (in Chinese)

DOI:10.3321/j.issn:1000-6923.2000.05.006 URL [本文引用: 1]