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1.
研究棕榈酸、儿茶酚和香草酸对土壤中Cd行为的影响表明,土壤中儿茶酚对水稻的毒害浓度为100mg·kg-1,而香草酸则为500mg·kg-1.当土壤中儿茶酚为5000mg·kg-1时,水稻籽实中Cd浓度降到0.008mg·kg-1,土壤淋溶液中Cd浓度降为0.005mg·L-1,3种有机物均能增加土壤中有机结合态Cd的比例,5000mg·kg-1的儿茶酚处理,土壤中有机质结合态Cd占总Cd的48.71%.  相似文献   

2.
对冀北高原闪电河水库上游20km长的河段的多介质体中总P含量及其动态变化分析表明,同源水体的总P含量各段不一,其中最高量(0.0824mg·L(-1))为最低量(0.0228mg·L(-1))的3.6倍;不同介质体总P含量以土壤(3402mg·kg(-1))>淤泥(1992mg·kg(-1))>岩石(542mg·kg(-1))>水体(0.0553mg·L(-1))的排序递减,并随温度升高而增高.  相似文献   

3.
本文在研究磷素几种形态的动态变化基础上,运用生态系统理论,利用系统分析的方法,分析了磷在植物-土壤系统中的流通、积累和归还的特点,得出如下结果:1.磷素在系统内99%以上分布在土壤中。2.群落内磷的再利用量为3.6755kg·ha ̄(-1)·yr ̄(-1)。3.群落每年吸收的磷为3.4063kg·ha ̄(-1)·yr ̄(-1),地上部归还土壤为0.1447kg·ha ̄(-1)·yr ̄(-1),地下部归还土壤为1.8111kg·ha ̄(-1)·yr ̄(-1),输出仅占吸收量的42.24%,磷素在群落中每年净积累为0.35ks·ha ̄(-1)·yr ̄(-1)。4.磷在各库内的周转时间是:地上植物活体为1.3364年,立枯体为6.4350年,活根为1.0887年,死根为2.4378年,有机磷为833.3年。  相似文献   

4.
Cd对桑叶品质,生理生化特性的影响及其机理研究   总被引:25,自引:2,他引:25  
土壤中不同浓度的Cd对桑叶产量、品质、生理生化特性的影响以及Cd在桑叶亚细胞各组分中分布量的研究表明,当土壤Cd浓度小于22.3mg·kg-1时,桑叶产量、可溶性糖和含氯化合物含量高于或接近对照;桑叶叶绿素含量、细胞膜透性和超氧化物歧化酶、过氧化物酶及蛋白酶的活性无明显影响或有促进.当土壤Cd浓度大于22.3mg·kg-1时,Cd对桑叶产量、营养物质含量、生理生化作用的影响随之明显,并表现其毒害作用.根据Cd在桑叶亚细胞组分中的分布规律.对其影响机理进行了探讨,说明桑树是一种具有一定耐Cd性的经济作物.因此,可利用其耐Cd性,在被Cd污染土地上种植桑树.  相似文献   

5.
用0.01mg·L~(-1)三十烷醇磷酸酯钾或0.1mg·L~(-1)三十烷醇溶液培养的水稻幼苗,生长加速,苗高、苗鲜重、苗干重、苗粗壮度、根鲜重和根干重均增高。在幼苗生长后期,两者还可提高幼苗存活率。  相似文献   

6.
深圳福田白骨壤群落Cr,Ni,Mn的累积及分布   总被引:17,自引:2,他引:15  
探讨了深圳福田自然保护区白骨壤红树林对Cr、Ni、Mn的吸收、累积及分布.结果表明,该林地土壤Cr、Ni、Mn含量从底层至表层逐步提高;表层(0~30cm深)3种元素含量分别为7.97、25.0和537μg·g-1,贮量分别为1099.86、3450.00和74106.00mg·m-2.白骨壤植物各部位Cr、Ni、Mn含量范围分别为0.28~0.75、0.43~7.65和25~1552μg·g-1;植物对表层土壤加权平均富集系数为Mn>Ni≈Cr.该群落Cr、Ni、Mn的现存累积量分别为6.06、20.76和1631.17mg·m-2,年净存留累积量分别为0.43、1.43和107.98mg·m-2;林地残留物相应元素储量分别为Cr78.00μg·m-2、Ni1536.33μg·m-2和Mn405.54mg·m-2.该林区3种不同类型群落叶层Cr、Ni现存累积量为白骨壤林>桐花树林>秋茄林,Mn为秋茄林>白骨壤林>桐花树林.  相似文献   

7.
粉绿铁线莲挥发油成分分析   总被引:6,自引:1,他引:5  
利用气相色谱-质谱联用技术对青海粉绿铁线莲的挥发油成分进行了研究,共鉴定出59种组分,其中主要成分为十六酸乙酯,9,12,15-十八三烯酸乙酯,亚油酸乙酯,十九烷,正二十五烷,正二十六烷,6,10,14-三甲基-2-十五烷酮,双(2-乙基己基)邻苯二甲酸酯,十八烷酸乙酯,N-苯基-萘胺等,其中十六酸乙酯的含量最高,占挥发油成分总量的24.06%,检出成分占挥发油总量的87.8%。  相似文献   

8.
对稻萍结合系统细绿萍共生固N量研究表明,萍的固N力在整个生长季不同时期有所变化.最高固N率出现在6月初,萍固N量随其接种量和水稻行距增加而增加.50~10cm宽窄行交替的水稻行距和1500kg·hm-2的萍接种量的稻萍结合系统的总固N量为107.1kg·hm-2,而30cm等行距的325kg·hm-2的萍接种量的稻-萍结合系统的总固N量仅为36.0kg·hm-2  相似文献   

9.
杧果采后生理研究   总被引:2,自引:0,他引:2  
适期采收的果.采收时呼吸速率为23.2mgCO2·kg(-1)h(-1)果皮深绿色.果肉硬度>30P/cm2.置室温下(30℃)8d出现呼吸高峰,速率132.9mgCO2·kg(-1)h(-1),果皮的颜色黄绿各半.果肉硬度8—9P/cm2。采后12—14d果实达到完熟,果皮金黄色,硬度<3P/cm2,呼吸速率下降到39—45mgCO2·kg(-1)h(-1)。试验结果还表明.可溶性糖、还原糖、非还原糖、固形物等含量.均在采后第5天明显增高,果皮从深绿转为淡绿色。可溶性糖在采后第14天增至最高.达9.92%,此时可滴定酸度下降至0.14%.PH值升至6.15,此时为果实的最佳供食状态.生产上可据此为制定果贮藏措施提供依据.  相似文献   

10.
农田生态系统N、P营养平衡及其肥料效应   总被引:5,自引:1,他引:4  
9年的农田生态系统N、P营养平衡定位试验研究表明,N、P肥配合施用,实行秸秆还田,可提高土壤有机质和全N含量,使土壤速效和迟效P库容量得到补充.最后几年的P肥利用率达21.1—65.1%,N肥为49—75%.储备性施P第1年的利用率只有6.5-7.3%,而前3年之和达到24—28.5%,9年3个时段平均利用率27.9—42.8%,补偿性施P的19.5—42.9%.施P65.5kg·ha-1·yr-1时,既能满足作物对P的需求又能补充土壤速效P库容量.  相似文献   

11.
通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.  相似文献   

12.
The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.  相似文献   

13.
14.
龙胆科药用植物化学成分的研究现状   总被引:16,自引:0,他引:16  
龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。  相似文献   

15.
16.
真菌类遗传学分析的知识结构教学   总被引:5,自引:2,他引:3  
罗桂花 《遗传》2002,24(3):349-350
本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.  相似文献   

17.
Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l−1 glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l−1) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.  相似文献   

18.
The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.  相似文献   

19.
Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m−2 s−1. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to Pfr.  相似文献   

20.
目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。  相似文献   

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