共查询到17条相似文献,搜索用时 94 毫秒
1.
2.
森林生态系统铝毒危害研究进展 总被引:4,自引:2,他引:2
铝毒是酸性条件下抑制林木生长、造成森林大面积衰退的主要原因.近年来, 世界各国针对铝毒害机理及植物的耐铝机制进行了大量研究, 然而目前研究者对植物铝毒报道多限于农作物, 对林业铝毒的综述性报道还不多见.文中从森林土壤铝毒产生的原因、铝毒害机理、林木响应机制、铝毒对森林生态系统的危害以及防治措施等方面综述了森林生态系统铝毒的研究进展, 对我国森林资源保护和林木管理具有重要意义; 并提出林业铝毒研究存在的问题及今后的研究方向, 为进一步开展林业铝毒研究提供参考. 相似文献
3.
不同铝毒害对毛竹笋营养品质影响的研究 总被引:3,自引:0,他引:3
铝毒害是酸性土壤中植物生长发育的一个主要限制因素,为了探讨不同铝毒害对毛竹笋营养品质的影响规律,试验采用二因素正交旋转回归设计,分析不同试验处理对笋品质的影响。 相似文献
4.
铝对植物生长发育及生理活动的影响 总被引:1,自引:0,他引:1
铝是地壳中含量最高的金属元素,以固定态形式存在的铝对植物和环境没有毒害作用,而离子态铝才对其产生影响。通过过量铝对小麦、黑麦、荞麦、甘蔗、杉木、马尾松等植物的生长发育及生理活动影响的诸多研究成果归纳分析认为:(1)铝主要对植物的根、茎、叶、花、果实、种子6个器官的生长发育造成影响,进而导致植物产量的下降;(2)铝对植物的一些生理活动,如有机酸的分泌、细胞活动、酶活性光合作用造成不良影响。据此对植物的耐铝性及其遗传特性进程了分析;并对其相关的研究以讨论的方式作了展望。 相似文献
5.
6.
7.
在酸性土壤中,铝对林木的毒害是限制林木生长、降低林木生产力、进而导致森林退化的主要因素之一。目前,国内外在林木铝毒害及耐铝机制方面已有较多的研究,但关于林木耐铝的生理和分子机制的综述性报道很少。文中综述了近年来林木对铝的富集、铝对林木生理和分子水平上的毒害等方面的研究进展,总结了林木耐铝的生理机制和分子机制,简要介绍了外源添加物对林木耐铝毒的调控机制,提出了今后有关林木铝毒需进一步研究的重点,以期为林木铝毒的深入研究提供参考以及为缓解我国酸性土壤林木铝毒害及森林的健康持续经营提供参考。 相似文献
8.
9.
植物对土壤重金属的解毒机理 总被引:1,自引:1,他引:0
近些年来,重金属如Zn、Cu、Cr、Cd等过量后引起了一些毒害问题,从而造成周围生态环境急剧恶化。因为重金属不会被生物进行分解,只会在生物体内进行富集或者转化,并且超过一定的浓度范围会发生毒害作用,包括蛋白质的变性沉淀以及酶的活性降低;植物生物量的减少、作物产量以及质量降低等。因此,对重金属的毒害问题进行治理十分重要。文章从植物的解毒机理出发,阐述了植物的螯合作用、根系分泌物作用、菌根作用、细胞外排作用以及抗氧化系统作用对土壤重金属的解毒机制。 相似文献
10.
11.
12.
Lignin prepared by a modified Klason method (KSL) was modified with ozone followed by alkaline treatments. The original and
modified KSLs were subjected to a plant growth test with radish (Raphanus sativus L. var. radicula Pers.) in the presence of AlCl3 (37.5 μM) to assess their ability to reduce aluminum toxicity. The formation of an aluminum complex with these KSLs was also
examined by potentiometry. Neither the original nor alkaline-treated KSLs had an effect on aluminum toxicity or the formation
of a complex, except for the alkaline-treated KSL at a maximal dose of 250 mg/l, which reduced aluminum toxicity. However,
all the KSLs modified with ozone and alkali were effective at forming a complex and reducing aluminum toxicity. The dose of
saponified ozone-treated KSLs required to reduce aluminum toxicity became lower and their water solubility increased as the
ozone treatment was prolonged. These findings clearly show that water solubility and the ability to form a complex with and
reduce the toxicity of aluminum were improved by ozone treatment of KSL. 相似文献
13.
Melastoma malabathricum L. (melastoma) is an Al-accumulating woody plant that grows in tropical Southeast Asia in acid soils with high aluminum (Al) concentrations and low nutrient concentrations. Because oxalate serves as a ligand for Al accumulation in melastoma leaves and citrate is the ligand associated with Al translocation from roots to shoots, we investigated the role of organic acids in the adaptation of melastoma to growth on these soils. Phosphorus starvation increased oxalate concentration in the rhizosphere, enabling melastoma to solubilize insoluble aluminum phosphate in the rhizosphere. Increased availability of P and Al in the rhizosphere enhanced growth. In the xylem sap, the concentration of citrate increased with increasing Al concentration. In contrast, the concentrations of malate, succinate and alpha-ketoglutarate in the xylem sap decreased with increasing Al concentration, suggesting that tricarboxylic acid cycle enzymes were affected by Al treatment. 相似文献
14.
以接种褐环乳牛肝菌和未接种的马尾松幼苗为试验材料,采用水培法研究不同浓度铝(Al^3+)处理(0、0.2、0.4、0.8和1.2 mmol·L^-1)对菌根化和非菌根化马尾松幼苗生长、营养元素吸收的影响,揭示菌根化马尾松苗木对Al^3+的适应机制,为减轻马尾松苗木铝毒害现象提供理论和技术依据。结果表明,在相同浓度Al^3+胁迫下,接种褐环乳牛肝菌的马尾松幼苗苗高、生物量、根系形态以及对氮(N)、磷(P)、钾(K)的吸收能力均优于不接种的马尾松苗。马尾松幼苗苗高、干物质量积累以及根系生长随着Al^3+浓度的增大均呈现先升后降再升的趋势,随着Al^3+浓度的逐渐增大,马尾松幼苗根、茎、叶中的N、P、K含量呈现出低促高抑的趋势,根、茎、叶中Al^3+含量的分配为根>茎>叶。Al^3+胁迫下,接种褐环乳牛肝菌的马尾松幼苗,通过改变马尾松幼苗根系结构,促进了幼苗的生长,特别是根系的生长,以及对N、P、K等营养元素的吸收,抑制了根系吸收Al^3+,提高了马尾松幼苗的耐铝能力。 相似文献
15.
We characterized the lignin fragments in the alkaline oxygen delignification-stage waste liquor from a pulp and paper mill as a soil-conditioning agent. Chemical reactions of this lignin fragment should be very similar to those of alkaline-oxygen treatment of kraft lignin. Alkaline oxygen delignification-stage waste liquor was subjected to gel filtration chromatography and four different molecular weight fractions (F1, F2, F3, and F4) were obtained. These four fractions were used in plant growth experiments. A very clear positive effect in removing the aluminum (Al) toxicity to root growth of radish was found for all four fractions. When aluminum concentration in the nutrient solution was as low as 0.5 ppm, root elongation was practically inhibited, but if 12.5 ppm of lignin fragment was added, the toxic effect was practically removed and root elongation better than that in the control was observed. However, each fraction showed different performance in removing aluminum toxicity, and the highest molecular weight fraction, which contained some aromatic structures, showed better performance in removing Al toxicity. The reason for their different behaviors on Al toxicity was also examined.Parts of this report were presented at the 12th International Symposium on Wood and Pulping Chemistry, Madison, USA, June 2003 and the 48th Lignin Symposium, Fukui, Japan, November 2003 相似文献
16.
酸雨对陆生植物的影响机理 总被引:9,自引:0,他引:9
综述酸雨对陆生植物的影响行为、对植物组织和细胞结构及其代谢功能等直接影响机理,以及通过改变土壤理化性质等对植物造成的间接影响机理,并讨论酸雨与其它污染对植物的复合作用及提出研究展望。 相似文献