不同品种大白菜苗期吸收积累镉的差异研究

利用实验室水培模拟轻度镉污染土壤研究了13个大白菜品种苗期吸收积累镉的差异。结果表明,不同品种大白菜地上部和根部的镉含量存在显著差异,其中,603大白菜地上部镉含量较低(104.7 mg kg-1),耐性指数较高,在轻度镉污染土壤上种植603大白菜有利于降低镉污染的人类健康风险。不同大白菜品种在受到Cd胁迫时,其叶绿素含量和组成均有显著差异,为耐性机理研究提供了理论依据。     

低浓度镉对大白菜苗期生长及营养元素吸收积累的影响研究

在实验室用水培模拟轻度污染土壤,研究低浓度 Cd(5 1.μmol/L)对不同Cd耐性的4个大白菜品种苗期生长及营养元素吸收积累的影响.结果表明,低浓度Cd对耐性强的品种的生长有促进作用,对耐性差的品种的生长有抑制作用.5umol几Cd显著促进大白菜根系对S、Cu的吸收,分别增加22.0%～58.0%、45.9%～116.0%,但抑制S、Cu向地上部转运;大白菜地上部K、P、Ca、Mg、Mn、Zn含量受到Cd的较强抑制,且抑制程度存在品种差异.     

镉对小麦（Triticum aestivum）干物质积累、转移及籽粒产量的影响

采用大田试验以不同镉耐性的洛麦23（镉耐性弱）和中育10号（镉耐性强）为试验材料,研究了镉（0、10、50、100mg·kg-1）对不同镉耐性小麦品种干物质积累、干物质转移、叶面积指数及产量的影响。结果表明,一定浓度范围的Cd胁迫可以增加小麦的叶面积指数,当超过这一浓度范围则呈现为抑制作用,这一临界值因小麦品种不同而异。结果同时表明,一定浓度范围的Cd处理对小麦各器官的干物质积累及同化物转移同样具有促进作用,这一临界值不仅因小麦品种不同而异,也因器官不同而异。镉胁迫导致小麦籽粒产量下降,3个Cd处理下洛麦23籽粒产量较对照依次下降了8.3%、34.3%、51.6%,中育10号产量下降程度较小,依次下降了3.7%、9.5%、29.3%。整体而言,镉胁迫影响了小麦的正常生长发育,导致小麦减产。同时,这种影响也存在品种差异性,镉耐性较大的中育10号叶面积指数受抑制程度较小,干物质积累量较大,各器官同化物转移途径受Cd损伤较轻,最终在籽粒产量上表现优于镉耐性较弱的洛麦23。     

镉胁迫对不同基因型玉米生长和镉吸收分配的影响

为比较玉米不同类型及其基因型对重金属镉富集特性的差异,筛选出具有镉(Cd)低积累潜力的玉米品种,通过盆栽模拟试验,研究3种玉米类型(普通玉米、甜性玉米和糯性玉米)的6个基因型(掖单13、郑单-958、苏玉糯-2、沪玉糯-2、金珠蜜超甜和申甜-1)在镉中度污染胁迫(3 mg·kg^-1)与轻度污染胁迫(1 mg·kg^-1)下植株生长及镉吸收分配特征。结果表明,轻度镉胁迫(Cd1)能够促进所有玉米基因型的生长,而中度镉胁迫(Cd3)降低了掖单-13、苏玉糯-2和沪玉糯-2基因型的生物量,同一镉水平下植株的生物量表现为普通玉米>甜玉米>糯玉米。随着土壤镉含量的提高,镉在普通玉米基因型根中的分配量大于甜型玉米和糯型玉米,但同一镉水平下普通玉米茎、叶和籽粒中的镉含量显著低于甜性玉米和糯性玉米。参试6个玉米基因型中普通玉米郑单-958基因型对镉的生物富集和转运能力最小。依据我国食品中污染物限量标准(GB2762-2017)和饲料卫生标准(GB13078-2017),郑单-958基因型在土壤轻度镉污染(Cd1)下籽粒中镉含量为0.083 mg·kg^-1,未超过国家食品安全标准(≤0.1 mg·kg^-1),2个普通玉米基因型和2个甜玉米基因型籽粒中的镉含量在土壤中度(Cd3)、轻度(Cd1)镉污染下均未超过国家饲料卫生标准(≤0.5 mg·kg^-1)。本研究结果为中、轻度镉污染耕地进行玉米安全生产提供了理论依据。     

不同品种烟草生长和镉及营养元素吸收对镉胁迫响应的差异

通过盆栽试验研究了两个品种烟草Xanthi和贵烟11号生长、镉的吸收和运转及营养元素吸收对镉胁迫的反应.结果表明,Xanthi的生长量在3 mg/kg Cd处理时增加.10 mg/kg Cd处理时降低,贵烟11号根及地上部的生长则随土壤镉浓度的提高而降低,表明Xanthi较贵烟11号对镉有更强的忍耐能力.提高土壤镉水平,烟草根和地上部镉含量增加,镉的转运系数下降,下降幅度为Xanthi＞贵烟11号.两个品种烟草镉的向上转运速率,Xanthi表现为先上升后下降的过程,贵烟11号则持续上升.表明Xanthi根部阻止镉向地上部运输的能力较贵烟11号强.镉对两个品种烟草N,K,Zn,Mn的吸收有促进作用.对Fe,Mg的吸收有抑制作用.对Xanthi的P吸收有促进作用、Ca吸收有抑制作用,对贵烟11号的P含量影响不明显,却提高贵烟11号的Ca含量.     

模拟铅胁迫下玉米不同基因型生长与铅积累及各器官间分配规律

我国遭受重金属污染的土地中有87%左右是中轻度污染土壤类型,深入研究不同植物对重金属的吸收和转运积累规律,是科学利用植物和土壤资源的重要基础工作。通过玻璃网室盆栽模拟污染的手段,研究了玉米6种基因型在铅中度污染胁迫（800mg·kg^-1）与轻度污染胁迫（400mg·kg^-1）下的植株生长、铅吸收积累及其在玉米不同器官间分配的规律。结果表明,不同铅污染胁迫下,玉米不同基因型的生长及铅吸收量达到极显著差异（P〈0.01）,铅在不同器官之间的分布形式也存在显著的基因型差异。轻度铅污染胁迫不同程度地促进玉米所有供试基因型的生长,而中度污染胁迫下糯玉米基因型生物量最大。与正常土壤对照条件下的表现相比,不同程度铅污染胁迫下基因型申甜1号的生物量增幅最大,表现出较强的铅耐受能力。不同基因型的玉米体内铅积累量随着污染水平的提高而增加,各器官内铅积累浓度差异规律为根〉叶〉茎〉穗。掖单13号具有较强的铅转运能力（TF=0.6628）,申甜1号的生物富集能力最强（BCF=0.0264）,掖单13号和申甜1号均具有较强的铅吸收和积累能力,属于潜在的高积累基因型。但掖单13号根部富集量少而穗部积累多,申甜1号根中铅积累较多而果穗中较少。2个甜玉米基因型果穗内铅积累量较少,其含量符合国家规定的食品生产相应的安全标准。     

无瓣蔊菜对镉的积累特性研究

为从农田杂草中筛选出镉超富集植物用于镉污染农田的修复,本研究以无瓣蔊菜为试验材料,通过模拟不同浓度镉胁迫条件,探究不同镉浓度处理对无瓣蔊菜生长量、光合色素含量以及镉富集特性的影响,揭示无瓣蔊菜对镉污染土壤的修复能力。结果表明,随着土壤镉浓度的增加,无瓣蔊菜的生长受到抑制但无毒害症状,当土壤镉浓度≤75 mg·kg-1时,无瓣蔊菜的叶绿素含量有所降低,但与对照间无显著性差异;当土壤镉浓度达到75 mg·kg-1时,无瓣蔊菜地上部分镉含量为112.77 mg·kg-1,根系镉含量为69.87 mg·kg-1,且植株根系和地上部分对镉的富集系数(BCF)和转运系数(TF)均大于1,说明无瓣蔊菜是一种镉富集植物。转运量系数(TAF)以及镉积累量与土壤镉浓度的回归分析表明,镉在无瓣蔊菜中的分布规律为地上部分根系。当土壤镉浓度≤50mg·kg-1时,镉元素从根系到地上部分的转运能力增强,有利于无瓣蔊菜富集镉。综上所述,无瓣蔊菜对镉有很强的耐性,可吸收土壤中的镉,并转运积累到地上部分,收获后将其迁移出土壤,以达到修复镉污染的目的。无瓣蔊菜适用于镉污染浓度在75 mg·kg-1以内的农田修复。本研究为筛选优良超镉富集植物材料提供了相关的科学依据。     

Cd/Cr复合胁迫下不同品种蔬菜对Cd和Cr积累与转运的差异研究

为筛选土壤重金属复合污染环境下低积累重金属蔬菜的预防品种,提高叶菜类蔬菜质量与安全,本研究采用盆栽试验,比较了Cd/Cr复合胁迫下17个蔬菜品种对重金属Cd和Cr的积累与转运的差异。结果表明,Cd/Cr复合胁迫下,17个蔬菜品种地上部茎叶中Cd和Cr含量差异显著,其含量均值分别为0.645±0.212 mg·kg FW-1和0.222±0.092 mg·kg FW-1,变异系数(CV)分别为32.87%和41.44%;Cd和Cr的转运系数(TF)均值分别为1.031±0.157和0.102±0.028,与对照相比分别增加41.43%和下降37.80%;地上部Cd积累是造成不同蔬菜品种植株生物量下降和耐性差异的主要因子;Cd/Cr复合胁迫下,不同蔬菜品种茎叶中Cd、Cr含量和转运系数的变化与对照相应品种间的变化均呈显著或极显著正相关,表明不同蔬菜品种重金属积累与转运具有遗传稳定性;聚类分析表明,17个蔬菜品种地上部Cd、Cr含量和转运系数由低到高分为4个类群,其中华绿二号(HL2)品种同时具有最低的Cd、Cr积累和转运能力,可推荐其作为Cd/Cr中轻度复合污染土壤环境下的重金属污染预防品种(Cd+Cr-PSC)。本研究为叶菜类蔬菜低积累品种选育及解决中、轻度复合污染土壤的可持续利用和食品安全提供了有效途径。     

圆叶决明（Chamaecrista rotundifolia）对重金属镉胁迫的响应及镉吸收效果研究

以圆叶决明2228（Chamaecrista rotundifolia）为材料,采用土培法,研究重金属镉对圆叶决明2228保护酶（SOD和POD）、生长（生物量、株高、SPAD值和含水量等）的影响,同时分析圆叶决明对镉的吸收效果。结果表明,重金属镉胁迫下圆叶决明2228保护酶活性均随着镉处理浓度的升高呈先升后降的趋势,其中20mg·kg^-1镉胁迫下SOD酶活性最强,50mg·kg^-1镉胁迫下POD酶活性最强;镉对圆叶决明的生长抑制表现为抑制植物的生长,降低株高和生物量,但与叶绿素相关的SPAD值无显著变化。通过镉含量分析可知,圆叶决明2228吸收的镉量均未超过镉临界指标含量,因此该植物不是镉超富集植物,但生物富集系数大于1,为镉耐性植物。由于圆叶决明生长过程中生物量大,在生长过程中可通过生物量带走部分重金属镉,圆叶决明2228具有修复轻度镉污染土壤的潜能。     

铅胁迫对19个品种草坪草种子萌发和幼苗生长的影响

用浓度分别为0(对照)、200、400、600mg/L的Pb2+分别处理19个品种草坪草的种子,测定了供试种子发芽势、发芽率、幼苗根长、苗长、鲜重、叶绿素含量、丙二醛含量等7项指标,比较19个品种草坪草生长初期耐铅性的强弱。结果表明：在不同浓度Pb2+胁迫下,有的品种种子发芽势、发芽率、幼苗根长、苗长、鲜重、叶绿素含量呈先上升后下降的变化趋势,有的品种这些指标呈下降变化趋势;有的品种丙二醛含量呈先下降后上升的变化趋势,有的品种丙二醛含量呈上升的变化趋势。通过聚类分析,Pb2+400 mg/L胁迫下将19个草坪草品种的耐铅性分为3 类;耐铅性强的品种有热浪;耐铅性较强的有星火、回报、绿城、爱瑞3号、家园、美洲豹3号、3A、麦哲伦、自豪、里园2号等; 耐铅性弱的有晚霞、本特、橄榄球2号、高地、优异、优美、午夜、抢手股;并通过主成分分析进一步确定19个品种在Pb2+400 mg/L胁迫下耐铅性由强到弱的顺序为热浪＞星火＞爱瑞3号＞3A＞回报＞美洲豹3号＞绿城＞家园＞自豪＞里园2号＞麦哲伦＞晚霞＞本特＞橄榄球2号＞高地＞优美＞抢手股＞午夜＞优异。     

不同芹菜品种镉吸收和运转差异研究

【目的】 研究镉胁迫下芹菜生长、镉吸收和向上运转品种间差异,为筛选镉低积累型芹菜品种减少镉对人体的危害提供依据。 【方法】 以10个芹菜品种为试材进行基质无土栽培试验,基质为蛭石,营养液采用1/2华南农业大学叶菜类营养液配方,以只浇灌营养液的处理作为对照,浇灌含15 mg/L氯化镉（CdCl₂）的营养液为Cd胁迫处理;每3 d浇灌一次,每次浇灌0.2 L,累计浇灌15次,每盆Cd施用量为45 mg。移栽45 d后,测定生长指标与根、叶柄和叶片Cd含量。计算相对生长量（relative growth yield,RGY）和转运系数（translocation factor,TF）,并筛选出高、低Cd积累品种。分别对高、低Cd积累品种进行穴盘基育苗,14 d后采用华南农业大学叶菜类营养液配方进行营养液栽培,21 d后利用非损伤微测技术（non-invasive micro-test technology,NMT）测定根系分生区、伸长区和根毛区Cd2+离子流速。 【结果】 与非Cd胁迫相比,Cd胁迫使‘速生四季西芹王’、文图拉西芹’、‘四季小香芹’、‘实心香芹’、 ‘雪白芹菜’ 地下部受到显著抑制,对地上部无显著影响;Cd胁迫促进了 ‘四季小香芹’ 地上部生长;而 ‘种都金黄芹菜’、‘红芹’、‘鲍芹’ 地上部受到显著抑制,对地下部则无显著影响;‘马家沟芹菜’ 和 ‘速生香芹’ 地上部和地下部均生长均受到抑制。食用器官叶柄中Cd含量以 ‘种都金黄芹菜’ 和 ‘雪白芹菜’ 最高;‘速生香芹’ 和 ‘实心香芹’ 最低。地上部Cd含量高的 ‘种都金黄芹菜’ 和 ‘雪白芹菜’ 对Cd转运能力也最高;Cd含量低的 ‘速生香芹’ 对Cd转运能力也最低。在根系成熟区（根毛区）,‘种都金黄芹菜’ 较 ‘速生香芹’ 有更高Cd2+ 离子流速。 【结论】 Cd胁迫下,芹菜不同品种生长、Cd吸收、转运和积累存在显著差异。‘四季小香芹’、‘速生四季西芹王’、‘文图拉芹菜’、‘实心香芹’ 和 ‘雪白芹菜’ 较为耐镉;而 ‘种都金黄芹菜’、‘红芹’、‘鲍芹’、‘马家沟芹菜’ 和 ‘速生香芹’ 对镉敏感。‘雪白芹菜’ 和 ‘种都金黄芹菜’ 为高Cd积累型,‘实心香芹’ 和 ‘速生香芹’ 为低Cd积累型,其中 ‘实心香芹’ 表现为低Cd含量和高生长量。高Cd积累型芹菜较低Cd积累型芹菜有更强Cd2+ 吸收能力和Cd转运能力,根部Cd2+ 流速可用于低积累品种的快速筛选。      

小麦苗期吸收和积累镉能力的品种间差异

采用水培方法,研究了25个小麦品种苗期对镉的吸收和积累的差异,以期筛选具有Cd低积累潜力的小麦品种。结果表明,Cd对地上部干物重有显著抑制作用,对地下部干物重影响因品种而异,对春性品种有抑制作用,对半冬性小麦品种有促进作用。小麦对镉的吸收、积累、耐性指数以及镉运转效率有极显著的品种间差异。在1μmol·L-1的Cd处理下,根系镉含量为33.1～139.7mg·kg-1,积累量为2.12～9.78μg·plant-1,地上部镉含量为3.6～15.3mg·kg-1,积累量为0.45～1.44μg·plant-1,表明小麦体内的Cd主要积累在地下部而非地上部。因此,以地上部Cd积累量为筛选指标,将25个小麦品种划分为Cd高积累型、Cd中积累型、Cd低积累型。     

Genotypic Difference in Arsenic and Cadmium Accumulation by Rice Seedlings Grown in Hydroponics

Genotypic differences in arsenic (As) and cadmium (Cd) uptake and their translocation within rice seedlings grown in solution culture were investigated. Arsenic uptake and its translocation differed significantly between eight cultivars. The largest shoot and root As concentrations were found in cultivar ‘TN1’ and ‘ZYQ8’, while cultivar ‘JX-17’ had the lowest As concentration. Arsenic concentration in shoot or root of ‘JX-17’ was about 50% of that in cultivar ‘ZYQ8’. Specific Arsenic uptake (SAU) was found significantly different between rice cultivars, which was about 2-fold higher of ‘ZYQ8’ than that of ‘JX-17’. The Cd accumulation also differed significantly between cultivars. Rice cultivar ‘JX-17’ had the highest ability in Cd uptake, but the lowest ability in Cd translocation from root to shoot. The transfer factor (TF) of Cd had an important effect on Cd accumulation by rice seedlings. Arsenic can competitively inhibit P uptake by rice seedlings, P concentrations in shoots, or roots treated with As were significantly lower than those without As addition. However, the concentrations of P and As were positively correlated within these genotypes. The Cd immobilization by cell wall was an important mechanism for Cd detoxification. The cell wall bound 21–44% of total Cd in shoots and 25–59% of total Cd in roots of these tested genotypes. The genotypic differences in As and Cd uptake and translocation within rice seedlings provide the possibility of selecting and breeding genotypes and /or cultivars with reduced levels of As and Cd in rice grains.     

Genetic Variation in Cadmium Accumulation and Tolerance among Wheat Cultivars at the Seedling Stage

Exploitation of genetic differences to select wheat cultivars’ pollution-safe from cadmium (Cd) contamination requires better understanding of Cd uptake and translocation patterns. For this purpose, 15 wheat cultivars were grown in nutrient solution and exposed to four levels of Cd, i.e., 0, 15, 30, and 45 µM. The plants were harvested after 2 weeks of Cd exposure. Root and shoot relative dry matter (DM) was decreased in most of the cultivars, but some cultivars did not exhibit any toxic symptoms. The lowest Cd concentration in shoots was recorded for Lasani-2008 and Iqbal-2000 while the highest for Sehar-2006 and Inqlab-91. Both root absorption and translocation accounted for regulating Cd concentration in shoots. There was no relationship between relative DM and Cd concentrations in roots and shoots. The results suggest that wheat cultivars with low shoot Cd concentration but higher tolerance, i.e. Lasani-2008 and Iqbal-2000, could be used in breading programs for low Cd wheat.     

Phenotypic variations of wheat cultivars from the North China Plain in response to cadmium stress and associated single nucleotide polymorphisms identified by a genome-wide association study

Understanding the genetic mechanisms for cadmium (Cd) uptake and translocation in common wheat (Triticum aestivum) is of significance in food Cd contamination control. In this study, a diverse panel of 132 wheat cultivars was collected from the North China Plain. The cultivars were evaluated in terms of their phenotypic variations in response to Cd stress and subjected to a genome-wide association study (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with the phenotypic variations at the seedling stage. Significant phenotypic variations with high heritability were observed among the wheat cultivars exposed to 40 μmol L^-1 Cd for the studied traits, including root length (RL), shoot length (SL), root and shoot dry biomasses (RDW and SDW, respectively), root and shoot Cd concentrations (RCD and SCD, respectively), and Cd translocation factor (TF). Mean RCD, SCD, and TF ranged from 1.0 to 33.8, 0.125 to 2.022, and 0.009 to 0.321 mg g^-1, respectively. Cluster analysis showed that wheat cultivars with higher RL, SL, RDW, and SDW under Cd stress were able to accumulate more Cd in root, leading to a lower Cd TF. Mixed linear model-based association analysis detected 17 novel significant marker-trait associations (MTAs), four of which were significant at a genome-wide scale. Most of the significant MTAs controlled Cd TF and explained 17.17%-26.47% of the phenotypic variations. Some of the SNP loci were physically close to a reported Cd-related quantitative trait locus or gene on wheat chromosomes. Results of this study provided a list of wheat cultivars with the potential of low Cd accumulation and enriched our knowledge on the genetic basis of Cd uptake and translocation in wheat. Pyramiding breeding of superior alleles detected in this study may additionally reduce Cd accumulation of improved wheat cultivars with excellent agronomic traits.     

镉铜胁迫下紫苏的生长响应和富集特征研究

通过盆栽试验,分析了紫苏（Perilla frutescens（L.）Britt.）在Cd、Cu胁迫下生长响应及其对Cd、Cu的耐性、吸收和累积特征。结果表明,在Cd处理浓度≤60 mg.kg^-1和Cu处理浓度为≤600 mg.kg^-1时,紫苏株高和根长均随处理浓度提高而增加,此后则随处理浓度增加胁迫作用渐趋明显。植株地上部和根部Cd的最高含量分别是331.51和991.14 mg.kg^-1,Cu的最高含量分别为228.65和2 030.63 mg.kg^-1。植株地上部Cd和Cu的最大富集量分别为66.70和36.52μg.plant^-1。植株Cd、Cu富集系数分别为2.59-15.42和0.14-1.24,迁移系数分别为0.35-1.44和0.07-0.56。因此,该植物可用于Cd、Cu污染土壤的修复。     

不同镉积累类型小麦根际土壤低分子量有机酸与镉的生物积累

采用土壤培养方法研究低镉积累小麦烟 86103和高镉积累小麦莱州 953不同生育期土壤低分子量有机酸含量与组成 ,及其与镉生物积累的关系。结果表明 ,不同镉积累类型小麦在高镉土壤中其根系镉含量差异不显著 ,但地上部镉浓度烟 86103显著低于莱州 953,而在低镉土壤中根系和地上部镉浓度烟 86 10 3均显著低于莱州 95 3。根际土壤有机酸 (柠檬酸、酒石酸、乙酸和丙酸 )含量及有机酸总量均为低镉品种烟 86103显著低于高镉品种莱州953。两个品种不同生育期有机酸含量均表现为柠檬酸 酒石酸 丙酸 乙酸 ,且各有机酸含量占有机酸总量的百分数表现稳定。小麦镉的生物积累与有机酸种类没有特异性关系 ,但与有机酸的总量有关。根际不同有机酸的水平对于土壤镉的复合或螯合溶解 ,在引起两品种地上部镉生物积累的差异方面起重要作用。     

Effect of cadmium on growth and the uptake of cadmium and other elements by durum wheat

A solution culture study was conducted to determine the effects of cadmium (Cd) application on the uptake of Cd, potassium (K), zinc (Zn), manganese (Mn), copper (Cu), iron (Fe) and on the growth of seedlings of three wheat (Triticum turgidum L. var Durum) cultivars, Kyle, Nile, and SC84–994. Cadmium application decreased shoot and root biomass, root length, and leaf area. Cadmium application did not produce any differences among cultivars in these growth parameters. There were differential cultivar responses in the uptake of Cd and K but not for Zn, Mn, Cu, and Fe uptake. A solution Cd concentration of 0.1 μM did not affect the concentration of Cd and K compared to zero Cd but at and above 0.5 μM Cd, Nile had a higher concentration and contents of Cd and K in root and shoot than SC84–994 and Kyle. Kyle and SC84–994 were not different in any of the elements tested except K concentration in shoot where the order was SC84–994<Kyle<Nile. Cadmium application increased the Cd concentration but decreased the concentration of K, Zn, and Mn in root and shoot, while the Fe and Cu concentrations in shoot and root were not affected. Cultivar differences were observed in the translocation of Cd from root to shoot. In SC84–994 and Kyle, 0.5 μmole Cd/L decreased the total Cd translocated to shoot, Further addition of Cd did not affect Cd translocation, whereas in Nile, increased Cd concentration in solution did not affect Cd translocation to the shoot. A modified version of Weibull frequency distribution [y = a exp.(b.Cd^c)] was applied to explain the effect of Cd on plant growth parameters and on the uptake of K, Mn, Zn, and Cu in plants.     

镉积累差异水稻品种生长发育对清除NO的响应

  【目的】   研究一氧化氮 (NO) 对镉 (Cd) 胁迫下水稻苗期生理生化及氮代谢响应的调节作用,探讨通过清除NO提高水稻耐Cd能力的措施。   【方法】   以Cd高积累 (TN1) 和Cd低积累 (春江06) 品种为材料,进行了Cd胁迫 (40 μmol/L) 水培试验。以Cd胁迫营养液为对照,在对照基础上设置添加硝普钠 (Cd+SNP)、添加NO清除剂CPTIO (Cd+CPTIO)、添加硝酸还原酶抑制剂钨酸钠 (Cd+TU) 处理,共4个处理。处理后12天,测定不同处理对水稻幼苗生长、NO₃–-N分配、根系特性及光合特性的影响。   【结果】   NO对高Cd和低Cd积累水稻品种的影响不同。与对照相比,Cd+SNP处理降低高Cd积累水稻品种幼苗地上部和地下部NO₃?-N含量,但对幼苗生物量和氮素吸收没有显著抑制效果;Cd+CPTIO处理会提高幼苗生长、氮素积累量及氮效率 (P < 0.05);增加或清除NO处理均显著降低了地上部和地下部的Cd含量。对于低Cd积累水稻品种,Cd+SNP、Cd+CPTIO、Cd+TU处理间幼苗生物量、氮素吸收量均无显著差异。   【结论】   品种基因型对NO信号的调节敏感度不同,高Cd 积累品种清除NO处理可以显著抑制Cd的吸收和向地上部的运转,促进幼苗的生长和对氮素的吸收利用,抑制硝酸还原酶活性处理缓解Cd胁迫促进幼苗生长的效果不稳定。而对于低Cd积累水稻品种,清除NO处理也有一定的缓解Cd吸收和向地上运转的效果,但其重要性不如基因本身的拒Cd能力。因此,Cd胁迫下,高Cd积累水稻品种采用清除NO的措施可有效缓解Cd胁迫,促进水稻的生长,但对于低Cd积累水稻品种,清除NO也可以进一步降低Cd的向上运输,但是对水稻幼苗生长和氮素利用的影响不显著。