镉、铅积累与转运在冬小麦品种间的差异

在府河污灌区选取代表性农田,采用田间小区试验,研究了北方冬麦区适种的10个小麦品种对镉（Cd）、铅（Pb）积累与转运的差异,以期筛选出具有Cd、Pb低积累潜力且产量较高的小麦品种。结果表明,10个小麦品种的产量和籽粒中Cd、Pb含量在品种间存在不同程度的差异。石新633产量最高,为8 400 kg·hm^-2,较其他小麦品种高出7%~23%;石新828和济麦22次之,较其他小麦品种高出1%~15%;籽粒中Cd含量较低的是良星66和济麦22,分别比其他小麦品种低11%~48%和2%~42%。籽粒中Pb含量较低的是鲁元502和济麦22,分别比其他小麦品种低14%~49%和14%~40%。10个小麦品种籽粒中Cd、Pb含量均未超过食品安全国家标准的食品中污染物限量标准（GB 2762-2012）。对10个小麦品种籽粒和秸秆中的Cd、Pb含量进行聚类分析可知,济麦22、中麦175、良星66和鲁元502均属于籽粒、秸秆中Cd、Pb低积累类群。综合评价小麦产量、小麦地上部Cd、Pb含量、富集系数、转运系数等指标发现,济麦22为既高产且籽粒具有低积累Cd、Pb潜力的小麦品种,适宜在黄淮冬麦区北部Cd、Pb轻度污染区推广种植。     

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

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的上壤中,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....     

Cadmium Concentration in Grains of Japanese Wheat Cultivars : Genotypic Difference and Relationship with Agronomic Characteristics

The contamination of cadmium (Cd) into the food chain can be harmful because Cd causes chronic health problems. To evaluate the breeding potential reducing the Cd concentration in wheat grain, we compared Cd concentrations in 237 wheat genotypes including Japanese landraces, Japanese cultivars and introduced alien cultivars for breeding using grain samples collected from upland fields in 2004?5 and 2005?6 growing seasons. The Cd concentration in wheat grain significantly varied with the growing seasons and with the experimental fields. Cultivars bred in northern Japan, including the recent Japanese leading cultivar ‘Hokushin’, tended to have a low Cd concentration in grain compared with that bred in central and southern Japan. Simple correlation analysis between Cd concentration in grain and agronomic characteristics revealed that the Cd concentration in grain showed significant negative correlations with stem number, culm length and spikelet number per spike, and showed significant positive correlation with SPAD value (chlorophyll content) of flag leaf. Stepwise multipleregression analysis showed that the genotypic variation of Cd concentration in grain was associated with the culm length and spiklet number per spike. This study clarified the geographical pattern of genotypes with different Cd concentrations in grain in Japanese wheat cultivars. Cultivars originating from northern Japan may be useful genetic resources to develop cultivars with a low Cd concentration in grain to be grown in the areas where Cd accumulation in wheat grain is a problem.     

大、小麦对镉的吸收、运输及在籽粒中的积累

大、小麦是全球最重要的粮食作物 ,生产镉低积累量的大、小麦对人们的健康至关重要 ,因为镉易被大、小麦吸收并在其体内积累。大、小麦籽粒中镉的含量与众多因素有关。根部特性是决定植株吸收镉的关键所在 ,根部特性主要决定于品种特性。根系细胞壁对镉的固定、液泡对镉的钝化、木质部液中镉的向外运输以及镉在穗部韧皮部中再运输共同决定籽粒中镉的含量。本文阐述了镉在植物体内的吸收、运输以及在籽粒中的积累规律 ,并讨论了降低大、小麦籽粒中镉积累的育种与栽培途径     

不同花生品种对稻田镉富集及转运的研究

为研究湖南湘江流域稻田镉（Cd）污染治理方法,筛选稻田替代种植作物,于长沙县和湘阴市受污染稻田 改种花生,选用5个大果品种,设置2种（露地、覆膜）栽培方式,研究品种与栽培方式组合下对稻田Cd吸收、富集及 转运的影响。结果表明：稻田花生营养器官（根、茎、叶）Cd含量较高,生殖器官（果壳、籽仁）Cd含量较低,且品种间有明显差异。5 个花生品种的组织器官中Cd 含量最高的是茎（5.413~8.859mg·kg-1）,果壳和籽仁最少（0.523~ 1.326mg·kg-1）,但是籽仁Cd含量超出NY/T 1067-2006标准的规定值,食用安全存在风险。覆膜栽培尽管降低了花生茎、叶、果针、果壳及籽仁等的Cd含量,但提高了植株干物质重和Cd总积累,其中,营养器官（根、茎、叶）Cd富集系数高于2.5,生殖器官（果壳、籽仁）Cd富集系数为0.8~1.7。不同部位间Cd转移系数大小顺序为：根→茎秆>茎秆 →叶>果壳→籽仁>果针→果壳>茎秆→果针。不同品种的花生油中Cd含量范围在0.012~0.074mg·kg-1,符合标准, 因此花生油食用是安全的。以地上部单株干物质积累量及其Cd含量作为高镉积累筛选指标,5个品种中09-3106 的单株可高积累镉元素。建议在湘阴、长沙等地的Cd污染稻田进行覆膜栽培花生。     

Root Morphology and Anatomy Affect Cadmium Translocation and Accumulation in Rice

Paddy fields contaminated with cadmium (Cd) present decreased grain yield and produce Cd-contaminated grains. Screening for low-Cd-accumulating cultivars is a useful method to reduce the amount of Cd in the grains. The present study aimed to examine the roles of the root morphology and anatomy in Cd translocation and accumulation in rice plants. Twenty-two rice cultivars were used in the first experiment, after which two cultivars [Zixiangnuo (ZXN) and Jinyou T36 (JYT36)] were selected and used in subsequent experiments under hydroponic conditions. The results showed that there were significant differences in Cd concentrations in the shoots (ranging from 4 to 100 mg/kg) and the Cd translocation rates (shoot/root) (from 7% to 102%) among the 22 cultivars, and the shoot Cd concentration was significantly correlated with the Cd translocation rate of the 22 cultivars under 0.1 mg/L Cd treatment. Compared with cultivar ZXN, JYT36 had greater root Cd uptake and accumulation but lower shoot Cd accumulation and Cd translocation rate. The number of root tips per surface area of cultivar ZXN was greater than that of JYT36, while the average root diameter was lower than that of JYT36. Compared with ZXN, JYT36 had stronger apoplastic barriers, and the Casparian bands and suberin lamellae in the root endodermis and exodermis were closer to the root apex in both the control and Cd treatments, especially for suberin lamellae in the root exodermis with Cd treatments, with a difference of 25 mm. The results also showed that, compared with ZXN, JYT36 had greater percentages of Cd bound in cell walls and intracellular Cd but lower Cd concentrations in the apoplastic fluid under the Cd treatment. The results suggested that Cd translocation, rather than root Cd uptake, is a key process that determines Cd accumulation in the rice shoots. The root morphological and anatomical characteristics evidently affect Cd accumulation in the shoots by inhibiting Cd translocation, especially via the apoplastic pathway. It was possible to pre-screen low-Cd-accumulating rice cultivars on the basis of their root morphology, anatomical characteristics and Cd translocation rate at the seedling stage.     

小麦品种与生物有机肥联合修复农田镉污染研究

为筛选Cd积累低且产量较高的小麦品种,以6个北方小麦品种和6个南方小麦品种为试材,在安徽铜陵选取Cd重度污染与未污染农田进行小麦品种与生物有机肥联合修复田间对比试验。结果表明,Cd未污染农田中各小麦品种除了泰山24外籽粒Cd含量均未达到国家粮食安全标准;Cd重度污染农田中小麦籽粒Cd含量为1.21~2.41mg·kg-1,Cd均超标,南方小麦品种较北方品种籽粒中Cd含量更高且差异性更大;施用生物有机肥可降低Cd重度污染农田中各小麦品种的Cd含量,降低百分率为1.7%~57.8%,平均降低29.9%。施用生物有机肥的Cd重度污染农田中各小麦品种籽粒Cd含量与小麦茎、叶的Cd含量极显著正相关。Cd重度污染农田较Cd未污染农田各小麦品种产量均显著降低,平均减产率46.2%;使用生物有机肥使Cd重度污染农田小麦平均增产15.7%。各小麦品种籽粒Cd含量与产量极显著负相关。扬麦20、宁麦8号为籽粒Cd积累量较低、产量较高的品种;施用生物有机肥可有效降低小麦籽粒Cd含量、增加小麦产量。     

不同品种小麦种子萌发和幼苗生长对镉胁迫的响应

为了明确不同品种小麦种子萌发和幼苗生长对Cd胁迫响应的差异,以对Cd耐性不同的2个小麦品种(丰优2号和丰优9870)为材料,研究了Cd胁迫对小麦种子萌发、幼苗生长、α-淀粉酶和抗氧化酶活性的影响.结果表明,Cd胁迫显著影响了发芽指数、活力指数和根生长,幼苗根和芽要比种子萌发对Cd敏感,根较芽更敏感.随着Cd~(2+)浓度的增加,幼苗根、叶中的MDA含量、G-POD活性明显增加,SOD活性呈现先增加后降低的趋势,而CAT、APX和α-淀粉酶活性呈下降趋势,且Cd~(2+)浓度越高下降幅度越大.两个小麦品种在种子萌发过程中受Cd的毒害程度不同,其中对丰优2号的影响更明显,在较高浓度Cd~(2+)胁迫下,丰优2号的α-淀粉酶、CAT、APX活性明显低于耐Cd品种丰优9870,说明Cd胁迫对前者的毒害更严重.     

水稻植株镉积累分配的差异

采用盆栽土培法，研究了高镉型与低镉型水稻品种植株镉积累、分布的差异。研究表明，两类型水稻品种根系与茎鞘镉含量差异不显著，糙米镉含量差异最大，达极显著水平。低积累型品种根系、叶片镉积累小于高镉型品种，但差异不显著，而其茎鞘镉积累量、茎鞘镉与植株镉总量比值都大于高镉型水稻品种。这可能是低镉型水稻品种糙米锅吉量极显著小于高镉型品种的主要原因。     

铅-镉复合胁迫下玉米品种间积累铅、镉的差异

选用25个玉米品种为试验材料,盆栽条件下研究铅-镉复合胁迫下,玉米不同品种积累铅、镉的差异。结果表明,铅-镉复合胁迫下供试玉米品种各器官含铅、镉量总体表现为根>叶>茎>子粒;与对照相比,根、茎、叶的铅、镉含量均大幅度提高;供试玉米品种各营养器官间铅、镉均呈显著相关,但营养器官与子粒间无显著相关;复合胁迫条件下,9个供试玉米品种子粒中铅含量超过了国家规定的粮食卫生标准,所有供试玉米品种子粒中镉含量也超过了国家规定的卫生标准,而且镉的生物富集系数比铅的生物富集系数高,子粒重金属超标程度大的玉米品种,其生物富集系数和转运系数相对较高。     

小麦茎部镉积累性状全基因组关联分析及优异位点挖掘

小麦镉（Cd）污染日益加重,严重威胁食品安全和人类健康,培育和应用低镉积累品种是降低镉污染小麦风险的最有效途径之一,通过分子标记辅助手段可加快低镉积累特性小麦的筛选和培育。本研究选用175份小麦种质材料,种植于陕西省镉中度污染农田,对灌浆初期小麦茎部镉含量、镉富集系数和转运系数进行聚类分析,筛选出10个低镉积累特性种质。同时利用小麦660K单核苷酸多态性（SNP）芯片,通过3种模型对茎部镉含量、生物富集系数和转运系数进行全基因组关联分析,共鉴定到33个相关遗传位点,其中28个是新的SNP位点。针对茎部镉含量和转运系数3A上的2个主效QTL,开发了KASP标记,并在验证群体中明确了其准确性和实用性。基于基因注释和同源基因比对,预测了10个基因可能直接参与小麦镉积累转运相关生物过程;其中TraesCS3A02G289200基因是一个热休克转录因子,它在水稻中的同源基因（OsHsfA4a）被验证能够提高水稻对镉的耐受性。10个低镉积累特性种质及相关基因可用于小麦耐镉污染育种及有效分子标记开发。     

不同氮反应冬小麦品种幼苗素质及氮代谢关键酶活性的耐低氮差异研究

为了明确不同氮敏感型冬小麦品种的幼苗对低氮胁迫的反应,基于小麦籽粒产量和籽粒氮含量的耐低氮指数,对24个冬小麦品种进行了耐低氮丰产型和氮敏感型分类,并以典型品种为材料,比较了其幼苗(5叶龄)在不施氮(0mmol·L~(-1))和施氮(16 mmol·L~(-1))条件下,地上部和根部的干物质积累量、氮含量、氮积累量及其叶片和根部的硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性。结果显示,与施氮处理相比较,不施氮处理小麦品种的幼苗根部干物质积累量、根冠比均增加,地上部干物质积累量、氮含量和氮积累量、根部氮含量和氮积累量以及NR和GS活性均降低。在不施氮处理下,耐低氮丰产型小麦品种的幼苗地上部干物质积累量的降幅小于氮敏感型品种,根部干物质积累量和根冠比的增幅均大于氮敏感型品种;耐低氮丰产型小麦品种幼苗总根长和总根表面积显著增加,根直径显著下降;氮敏感型小麦品种幼苗根直径和总根体积显著降低。与氮敏感型品种相比,耐低氮丰产型小麦品种幼苗地上部、根部的氮吸收能力较高,NR和GS两种酶活性降幅较小。     

硝态氮供应对小麦根系形态发育和氮吸收动力学的影响

为给小麦氮素利用效率的提高及氮高效品种的选育提供依据,以秦麦11号和宁麦9号作为供试材料,采用溶液培养方法,研究了不同浓度硝酸盐对小麦根系形态发育特征和硝酸盐吸收动力学的影响。结果表明,在较低的浓度范围内,NO3-可增加小麦总根长和根尖数,促进根系生长;当NO3-浓度超过2 mmol/L时,总根长和根尖数受到强烈抑制,但由于根系平均直径的增加,根系总体积并未明显减少。两个供试小麦品种之间根系NO3-含量并无明显差异,而两个品种的叶片NO3-含量在介质NO3-浓度超过10 mmol/L时表现出了明显差异。叶片、根系NO3-含量与根冠比之间的关系可用一次函数来进行描述,与根长、根尖数之间的关系可用二次函数来进行描述。与宁麦9号相比,秦麦11号的NO3-吸收具有更高Vmax值和Km值,这可能与两个供试小麦品种根系形态特征的差异有关。     

Effects of Ammonium Chloride Fertilizer and its Application Stage on Cadmium Concentrations in Wheat (Triticum aestivum L.) Grain

Abstract

Chloride (Cl) in saline soil increases the cadmium (Cd) concentration in crops. Here, we conducted a field experiment to investigate changes in Cd concentrations in wheat grain after the application of the Cl-containing fertilizer ammonium chloride (NH₄Cl), with the aim of reducing its potential health risk. Effects of the application stage of NH₄Cl fertilizer and leaching treatment (i.e., heavy rainfall) were also investigated in field and pot experiments. Both field and pot experiments showed that the Cd concentration of wheat grain was higher with NH₄Cl fertilizer than with ammonium sulfate or urea fertilizers. Grain Cd concentration in wheat fertilized with NH₄Cl at the tillering–jointing and flowering stages in the field experiment was 0.223 mg kg^–1, which was about 1.5 times higher than that fertilized with urea. This finding is important because, in Japan, compound fertilizers containing NH₄Cl are commonly used in fields for wheat cultivation. NH₄Cl fertilizer application at the tillering–jointing and flowering stages had nearly equal effects on the Cd concentration in wheat grain. Basal dressing with NH₄Cl fertilizer increased Cd concentrations in wheat grain to a greater extent than topdressing (at thetillering–jointing and flowering stage applications) in a pot experiment that was protected from rain. Leaching treatment (assuming two lots of 100 mm rainfall) negated the effect of NH₄Cl fertilizer application on Cd concentration in wheat grain. We recommend the use of ammonium sulfate or urea preferentially as the nitrogen fertilizer because heavy rainfall rarely occurs during this period in Japan.     

不同供氮水平下加硅对香蕉生长与氮营养的影响

采用砂培方法,探讨在正常供氮(200mg/L)和高供氮条件下(400mg/L)加硅对3个香蕉品种生长与氮营养的影响。结果表明:正常供氮和高供氮条件下加硅显著影响3个香蕉品种的生物量、根系活力、硝态氮含量、全氮与硅含量,显著影响氮、硅在根系与地上部分的分配比例,不同品种香蕉响应特征不同,香蕉硅氮代谢相互影响。加硅对宝岛蕉和威廉斯蕉地上部分生物量或根系生物量在2个供氮水平间的变化规律影响不显著,加硅降低或提高这种变化程度。巴西蕉在正常供氮条件下、宝岛蕉和威廉斯蕉在高供氮条件下,加硅提高根系活力,分别较对照提高46.0%、38.4%和1.86倍;加硅降低巴西蕉根系氮与叶片氮含量比例,宝岛蕉、威廉斯蕉在正常供氮条件下加硅提高根系中氮/假茎氮含量比例;加硅显著提高香蕉叶片硅含量,较对照提高17.6%～102.3%;加硅对根系和假茎硅含量影响分别与供氮水平与香蕉品种有关;高氮不加硅条件下,根系中硅含量与氮含量呈显著正相关。     

锰-镉互作对水稻生长和植株镉、锰含量的影响

在水培条件下,设置不同水平锰、镉处理,研究了锰对镉胁迫下水稻生长及植株镉、锰、铁、锌含量的影响。在镉胁迫下,正常锰处理(约0.50mg/L)可显著缓解镉对水稻生长的抑制,表现为株高、根长、叶绿素(a、b)含量等参数均高于低锰处理。随着镉处理水平的提高,水稻根系与地上部的镉含量随之上升;在同一镉处理水平下,植株地上部和根系镉含量因培养液中锰水平不同而异:随着锰处理水平的增加,水稻根系中的镉含量下降,而地上部镉含量则显著增加。随着锰、镉处理水平的提高,水稻植株地上部和根系中的铁、锌含量显著下降。此外,还对锰控制水稻镉积累的机理及其利用价值进行了讨论。     

土壤剖面硝态氮非均匀分布条件下小麦根系生长和氮素吸收特征

为探讨土壤硝态氮非均匀分布条件下小麦根系生长及氮素吸收特征,选用石麦15、衡观35、H10和L14等4个小麦品种为材料,进行土壤分层培养试验,模拟土壤剖面中上下层硝态氮空间分布差异,测定和分析了小麦根系长度、直径、分布等形态学特征及植株氮素含量和累积量。结果表明,当土壤中硝态氮施用量上层较低、下层较高时,小麦植株根系总长和表面积在上下土层中分布比值降低,根系趋向下层土壤生长。上下层土壤中硝态氮施用量均较高时,上下层土壤中的根系总长和表面积比值较大,根系趋向上层土壤生长。土壤剖面不同层次中硝态氮供应非均匀条件下,小麦根系发育呈现明显的可塑性反应。小麦根系总长和表面积以及直径≤0.15mm的细根长(占整个根系的比重很大)与植株地上部氮含量和氮素积累量极显著正相关,与土壤中硝态氮含量极显著负相关。     

Proteomic Study for Responses to Cadmium Stress in Rice Seedlings

A proteomic approach including two-dimensional electrophoresis and mass spectrometric (MALDI-TOF MS) analyses was used to investigate the responses to cadmium (Cd) stress in seedlings of rice (Oryza sativa L.) varieties Shanyou 63 and Aizaizhan. Cd stress significantly inhibited root and shoot growth, and affected the global proteome in rice roots and leaves, which induced or upregulated the expression of corresponding proteins in rice roots and leaves when rice seedlings were exposed to 0.1 or 1.0 mmol/L Cd. The Cd-induced proteins are involved in chelation and compartmentation of Cd, elimination of active oxygen free radicals, detoxification of toxic substances, degradation of denatured proteins or inactivated enzymes, regulation of physiologic metabolism and induction of pathogenesis-related proteins. Comparing the Cd-induced proteins between the two varieties, the β-glucosidase and pathogenesis-related protein family 10 proteins were more drastically induced by Cd stress in roots and leaves of Aizaizhan, and the UDP-glucose protein transglucosylase and translational elongation factor Tu were induced by 0.1 mmol/L Cd stress in roots of Shanyou 63. This may be one of the important mechanisms for higher tolerance to Cd stress in Shanyou 63 than in Aizaizhan.     

不同钝化剂对镉污染小麦镉富集及产量的影响

为实现河套灌区轻中度Cd污染农田的修复与安全利用,在河套灌区轻中度Cd污染农田开展了为期两年不同钝化剂处理的大田试验,7种钝化剂分别为生物炭(BC)、海泡石(SEP)、膨润土(BE)、坡缕石(PA)、腐植酸(HA)、硅酸钠(SS)、硫酸锰(MN),以不施用钝化剂为对照(CK),分析了不同处理下小麦产量、生物量、各器官Cd富集系数和转运系数,比较了不同钝化剂的钝化效果。结果表明,2020-2021年,SEP和SS处理较CK增产显著,增幅为11.09%～81.49%,各器官生物量均有不同程度的增加,其中籽粒及根增加显著;SS处理显著降低叶部Cd含量,降幅为26.75%,SEP处理显著降低籽粒Cd含量,降幅达47.62%。钝化剂处理下,各部位Cd富集系数均<1,根部到叶部Cd最高。小麦籽粒Cd含量与茎中Cd富集系数呈极显著的正相关,与茎向叶部、根向穗部的Cd转运系数呈显著的正相关;2年茎的Cd富集系数对籽粒Cd富集系数均有显著正效应,穗到籽粒、茎到叶的Cd转运系数对籽粒Cd富集系数影响最大。海泡石和硅酸钠处理增加了小麦产量,降低了植株Cd含量,抑制了Cd在植株体内的转运富集;内蒙古河套...     

籽粒镉低积累小麦材料的筛选及稳定性分析

为筛选出在不同试验条件下籽粒镉（Cd）低积累且稳定的小麦材料,以2年大田试验获得的籽粒Cd积累存在差异的30份小麦材料为研究对象,采用不同Cd浓度的盆栽试验和不同Cd污染程度的大田试验对小麦材料籽粒Cd积累差异进行研究。结果表明,盆栽试验中,小麦籽粒Cd含量随土壤Cd浓度的增加而增加,且在材料间差异明显;聚类分析发现,有7份小麦材料（30389、MY1848、XK066-1、77782、HW2-2、中梁22、绵麦37）在不同Cd浓度下均表现出Cd低积累特性。在成都平原区和川南丘陵区大田试验中,30份小麦材料籽粒Cd含量变化范围分别为0.07~0.94 mg·kg^-1和0.23~0.69 mg·kg^-1,且在材料间与不同试验地点间差异均明显;聚类分析发现,有8份材料（30389、77782、良麦2号、12N551、济麦22、蜀麦375、中梁22、绵麦37）在不同试验地点均呈现籽粒Cd低积累特性。综合盆栽试验和大田试验结果,筛选到4份稳定的籽粒Cd低积累型小麦材料（30389、77782、中梁22和绵麦37）,可用于中轻度Cd污染农田的安全生产。