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1.
《生态学杂志》2015,(5)
研究了某汞矿区附近蔬菜地的汞污染现状及其对周围居民的健康风险。通过汞矿区附近连片菜地所采集的15种蔬菜中总汞含量的分析发现,不同蔬菜的汞含量水平依次为叶菜类茄果类块茎类,其中叶菜类生菜的汞含量最高(57 mg·kg-1),块茎类白萝卜的汞含量最低(1.67 mg·kg-1)。对叶菜类和块茎类蔬菜不同部位的汞含量分析发现,同种蔬菜的不同部位对汞的富集能力不同。无论叶菜类还是块茎类,地上部分的汞含量均高于地下部分。其中,叶菜类蔬菜地上部分的外叶、内叶和混合叶的汞含量水平为外叶混合叶内叶。红萝卜和白萝卜各部位对汞的富集能力相似,即叶片萝卜表皮萝卜根。同时,对研究区中13个点位大气和土壤总汞含量分析表明,大气中总汞的含量在128~1109ng·m-3,土壤中总汞的含量水平为3.88~91.62 mg·kg-1,均严重超标。通过对汞矿区居民摄入蔬菜的汞暴露评估与健康风险评价可知,单独蔬菜摄入不会危及附近居民健康,但若综合其他暴露途径,潜在健康风险较高。 相似文献
2.
本文分析了矿区地表异常地段的土壤汞水平和植物群落,提出了自然条件下划分野生植物含汞水平标准,并研究了它们积累汞的规律。在大气含汞量极高的情况下,强富汞植物,弱富汞植物和中富汞植物都相应增加体内的汞积累。野菊花,大叶胡枝子,牛筋树可以作为大气汞污染物的净化植物。矿区农田土壤含汞量较高,农作物可食部位的含汞量都超标,菜蔬类尤为严重。在植物群落汞积累与环境因子关系的探讨中,认为草本植物和部分灌木的汞积累与下层土壤有机质和坡向关系密切,木本植物老枝含汞量受下层土壤含汞量的控制,也受土壤干湿度的影响。 相似文献
3.
不同汞化合物对水稻、小麦的影响及作物对汞的吸收积累 总被引:4,自引:0,他引:4
本试验研究了5种汞化合物(HgS,HgO,CH_3HgCl,HgCl_2,C_8H_8O_2Hg)对水稻、小麦生长发育的影响及作物对汞的吸收、积累。结果表明,C_8H_8O_2Hg对作物的危害比HgCl_2和CH_3HgCl大,HgS的危害最轻。不同汞化合物对水稻蒸腾作用的抑制程度看出,C_8H_8O_2Hg的毒性大,HgS的毒性最小;抑制小麦光合作用的程度看出,HgCl_2的毒性大、HgS的毒性小。不同汞化合物处理的土壤中,水稻、小麦的含汞量是随着汞化合物的浓度增加而增加,以C_8H_8O_2Hg处理的土壤,作物吸收的汞最多,转移到地上部的汞最多,HgS处理的土壤,汞转移到地上部最少;小麦吸收的汞大部积累在根中,地上部(茎叶)的含汞量显著比水稻少;各处理的土壤总汞含量与水稻的含汞量相关性显著。土壤中的HgS、HgCl_2可以转化为CH_3HgCl,并转运到植物体各器官。 本试验是用盆栽试验的方法,土壤用不同浓度不同汞化台物处理。 用的“称重法”测定了水稻的蒸腾作用。用FQW-CO_2红外气体分析仪测定了小麦的光合强度。用F-732测汞仪测定了水稻、小麦不同器官和土壤中的总汞含量。用巯基棉气相色谱法测定了甲基汞的含量。 相似文献
4.
近年随着持续而又复杂环境的改变,自然界中生物和非生物胁迫频繁爆发,多种逆境胁迫严重影响了植物的正常生长和发育,尤其是农作物产量.逆境胁迫下植物体内代谢物的重塑是其基因与环境因素共同作用的结果,是植物体生理表型与体内生化水平的直接体现,逆境胁迫下代谢组的重塑很大程度上反映了植物体对逆境胁迫的响应和防御.代谢组学的兴起,为... 相似文献
5.
对福建漳江口红树林沉积物中重金属汞(Hg)含量的时空分布进行了研究。结果表明漳江口红树林湿地汞含量为0.0815 mg•kg–1—0.3431 mg•kg–1。在潮间带水平分布上, 从光滩到高潮位汞含量显著上升(P<0.05), 相对光滩, 红树林沉积物更易富集汞, 其中高潮位红树林底泥中汞含量最高。在垂直方向上, 大多数的汞富集在表层及亚表层, 随着深度的加深, 汞含量呈现下降趋势。汞在红树林湿地沉积物中的积累主要与有机碳(TOC), 含水率, 盐度相关。从计算的单一污染指数(Pi)来看, 漳江口地区汞污染等级为Ⅲ级以下, 大多数采样点属于自由污染或轻度污染。就该地区汞污染的时空变化趋势以及和其他红树林区汞污染状况的对比来看, 漳江口地区存在一定程度的汞污染威胁加剧的现象, 值得引起注意。 相似文献
6.
本文研究了受汞污染的农田土壤—植物系统中汞的分布,迁移和积累的规律。土壤中的汞在离污染源3公里的范围内含量最高;主要集中在0一20厘米的土壤上层,几乎不往下迁移。植物可以从土壤和大气中吸收、积累汞。在汉沽区没有发现由于汞污染所造成的植物受害症状。植物中的汞含量与土壤中的汞含量成正相关。土壤汞含量与水稻茎叶汞含量的相关系数为0.836(N=7),与糙米汞含量的相关系数为0.898(N=7)。植物不同部位的汞含量根>叶>茎>种子。不同作物种子比较,糙米>高粱>小麦。在大气中汞含量高的地段,植物地上部分汞含量高于根。土壤、植物中的汞不断地向大气扩散,而大气中的汞随着降雨、降尘等又不断地沉降到土壤和植物的气生表面,并可被植物吸收。汞向其邻近地区扩散的能力较小。 相似文献
7.
五里河沉积物汞的时空变化规律 总被引:1,自引:0,他引:1
研究了历史上受纳氯碱污染的辽宁省葫芦岛市五里河沉积物中总汞、甲基汞25年中的时空变化规律.结果表明,经过25年的变化,在人工治理和自然净化作用下,五里河不同地点沉积物总汞和甲基汞含量总体上呈现明显下降的趋势,甲基汞下降尤为显著;但沉积物中汞含量依然处于较高水平,总汞含量为0.491~26.395 mg·kg-1,平均13.766 mg·kg-1,超过辽宁省土壤汞背景值(0.037 mg·kg-1)371倍,甲基汞含量为0.253~12.079 μg·kg-1,污染严重的断面是污染源附近的化工桥以及下游河口附近的茨山北桥. 相似文献
8.
汞与硒在不同汞暴露水平地区猪肝脏和肾脏蛋白质中的分布 总被引:5,自引:0,他引:5
通过对贵州万山汞污染地区及北京地区猪肝脏和肾脏组织上清液进行凝胶过滤色谱分离(SephadexG 10 0 ) ,随后用原子荧光法测定它们蛋白质组分中汞和硒的含量 ,研究在汞暴露水平不同状态下微量元素汞和硒在动物体蛋白质分子水平上的分布 .发现这两个地区猪肝脏和肾脏组织上清液蛋白质组分中汞和硒的分布模式有明显差异 .贵州万山汞污染地区猪肝脏上清液中汞浓度比北京地区高 ,硒浓度也相应高 ,且前者与高分子量和低分子量蛋白结合的硒均明显高于后者 ;而北京地区猪肝脏上清液中的硒主要以与高分子量蛋白结合的形式存在 .贵州汞污染地区猪肝脏上清液中汞主要与高分子量蛋白结合 ,而北京地区猪肝脏上清液中汞则分布较为均匀 .贵州万山地区猪肾脏上清液中 ,含硒峰在高分子量蛋白区和低分子量区都有分布 ;而北京地区猪肾脏上清液中 ,硒则主要集中分布于高分子量蛋白范围 .这两个地区猪肾脏上清液中都有分子量约为 11kD的金属硫蛋白 (MT)存在 ,北京地区猪肾脏上清液中汞主要以与金属硫蛋白结合的形式出现 ,而贵州万山地区猪肾脏上清液中的汞除与金属硫蛋白结合外 ,尚有相当大部分是以与高分子量蛋白结合的形式存在 .研究结果表明 ,由于这两个地区汞暴露水平的差异 ,不仅使这两地区猪肝、肾上清液中的汞与硒含量 相似文献
9.
贵州盘县煤矸石中汞的环境效应 总被引:1,自引:0,他引:1
通过冷原子荧光方法测定了贵州盘县新鲜煤矸石、不同风化程度煤矸石及煤矸石风化土壤中植物的Hg含量,对该地煤矸石中汞的分布规律及其环境效应进行了研究。结果表明,新鲜煤矸石中汞含量平均为(0.137±0.076) μg·g-1,未表现异常富集。不同风化程度的煤矸石土壤Hg含量未有明显的变化规律,平均含量为(0.154±0.056) μg·g-1,略高于土壤背景值。但在自燃后的煤矸石风化土壤和受其淋滤影响的下部土壤中汞却表现为异常富集,平均含量高达(1.627±0.294) μg·g-1。煤矸石风化土壤尤其是自燃后的煤矸石风化土壤中Hg的植物可利用性都比较高,部分农作物中Hg含量超过了国家标准中食品Hg含量限值,要选择合适的作物进行栽培。 相似文献
10.
三江平原土地利用方式改变对湿地汞含量的影响 总被引:2,自引:0,他引:2
通过测定三江平原小叶章湿地、水稻田、玉米地土壤以及小叶章、乌拉苔草、毛果苔草、杨树叶及苔藓中的汞含量,探讨了湿地土壤和植物汞来源及分布特征,研究了土地利用方式变化对土壤汞含量的影响.结果表明,三江平原土壤汞含量0.006~0.208mg·kg-1,平均为0.053 mg·kg-1,高于黑龙江省土壤汞背景值含量.由表层至底层,小叶章湿地土壤中汞含量变化不大,水稻田及玉米地中汞含量变化较大.植物中汞含量表现为苔藓>乌拉苔草>小叶章>毛果苔草>杨>树叶,其中苔藓中汞含量高达0.132 mg·kg-1.相关分析表明,土壤中汞含量与可溶性有机碳含量呈显著正相关(r=0.269,P<0.05).干湿沉降及植物对大气中汞的吸收可能是本地区土壤中汞的主要来源.湿地开垦为农田后,土壤中汞含量降低了45.6%,而旱田改为水田后,土壤中汞含量则增加了18.3%. 相似文献
11.
VESICULAR-ARBUSCULAR MYCORRHIZA IN FIELD-GROWN CROPS 总被引:5,自引:2,他引:3
I. JAKOBSEN 《The New phytologist》1986,104(4):573-581
12.
VESICULAR-ARBUSCULAR MYCORRHIZA IN FIELD-GROWN CROPS 总被引:10,自引:6,他引:4
13.
Removing virus-infected plants from plots of Majestic potatoes at Rothamsted on 2 July 1947 did not reduce the spread of leaf roll but reduced rugose mosaic (potato virus Y) to about one-fifth of that in plots rogued on 21 July or left unrogued. Roguing Arran Pilot potatoes on 16 June or 2 July reduced leaf roll to five-sixths of that in unrogued plots; roguing on 16 June reduced rugose mosaic to about half that in plots rogued on 2 July, and about a quarter of that in unrogued plots. Lifting Arran Pilot potatoes in mid-August reduced virus diseases to about two-thirds.
Roguing flattened the gradient (decrease in percentage plants diseased with increasing distance from the source of infection) with rugose mosaic, but had little effect with leaf roll. Evidently any plants prevented by roguing from contracting virus Y were near the initially infected plants.
In 1948, Majestic and King Edward potatoes at three places were rogued during 22–24 June and tubers were dug during 28–30 July and again at the end of the season. Leaf roll spread more in Majestic than in King Edward, and rugose mosaic spread more in King Edward. Roguing reduced the spread of both by about one-fifth at Rothamsted, but had no effect at Sutton Bonington. At Bretton, in the Derbyshire hills, roguing had no effect on leaf roll, but prevented the spread of rugose mosaic.
The small benefit occasionally achieved by roguing in the ware-growing districts of England does not make the practice economically worth while. 相似文献
Roguing flattened the gradient (decrease in percentage plants diseased with increasing distance from the source of infection) with rugose mosaic, but had little effect with leaf roll. Evidently any plants prevented by roguing from contracting virus Y were near the initially infected plants.
In 1948, Majestic and King Edward potatoes at three places were rogued during 22–24 June and tubers were dug during 28–30 July and again at the end of the season. Leaf roll spread more in Majestic than in King Edward, and rugose mosaic spread more in King Edward. Roguing reduced the spread of both by about one-fifth at Rothamsted, but had no effect at Sutton Bonington. At Bretton, in the Derbyshire hills, roguing had no effect on leaf roll, but prevented the spread of rugose mosaic.
The small benefit occasionally achieved by roguing in the ware-growing districts of England does not make the practice economically worth while. 相似文献
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15.
THE EFFECT OF WEEDS UPON CEREAL CROPS 总被引:1,自引:1,他引:0
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J. T. WALKER 《Biological reviews of the Cambridge Philosophical Society》1969,44(2):207-243
1. It is vital that there should be no decrease in the rate of improvement of crop plants. In drafting the background to the inheritance of quantitative characters it is suggested that greater understanding of genetic mechanisms is needed rather than further increase in biometrical complexity. Selection is a very powerful force; it could be used to conserve genetic variation whilst effecting useful change. 2. Various breeding techniques, examined in a framework of directional, stabilizing and disruptive selection, are found to be tied to certain crops. Breeders of self-fertilizing plants handle quantitative variation differently from those working with outbreeders. 3. Physiological analysis and partitioning of characters have not in themselves made large contributions to solving problems caused by complex traits, but both have been informative in conjunction with biometrical studies. In some circumstances more use could profitably be made of selection indices. 4. Heterozygote advantage and genetic balance play major parts in stabilizing selection. Modal selection can sometimes lead to increased fitness, conforming with the concept of genetic homeostasis. 5. Disruptive selection has apparently operated during the evolution of crop plants. To be beneficial to breeders it should be multidirectional; intercrossing of peripheral lines might then form ‘springboard’ populations allowing further advance from selection plateaux. 6. As the boundaries of cultivation are extended so the need will increase for plant populations with inherent stability of performance. Few crops are yet amenable to the production of F1 hybrid seed, so polygenes should be manipulated to form balanced, heterozygous adaptive complexes. Systems of selection must be refined to deal effectively with the heterogeneous populations from which such complexes are likely to arise. 7. Studies on composite crosses and related projects tie in well with other work on selective forces in adaptation. New allopolyploids offer hope in some plant groups, but induced mutation is of restricted value. 8. Cryptic variation and selection can be important in many breeding methods, and should be considered when dealing with quantitative aspects. 9. Changes in locality can reveal startling amounts of unsuspected variability: such ‘environmental segregation’ could be harnessed, for example, by alternation of selection centres when breeding for general adaptability. 10. Persistence of variation, which may occur through selection favouring hetero-zygotes despite strict inbreeding, is also considered in terms of heterozygous gene complexes. Tightness of linkage is the key to the durability and behaviour of super-genes, and analysis of the simpler ones could lead to better understanding of the vastly complicated systems controlling fitness and productivity. 相似文献
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CARBON DIOXIDE IN RELATION TO GLASSHOUSE CROPS 总被引:1,自引:0,他引:1
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WIREWORM POPULATIONS AND THEIR EFFECT ON CROPS 总被引:1,自引:0,他引:1
D. J. Finney M.A. 《The Annals of applied biology》1941,28(3):282-295
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