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1.
Abstract

The characteristics of plant growth of hypernodulation soybean mutant lines NOD1-3, NOD2-4 and NOD3-7 were compared with their parent cv. Williams. The plants were grown using hydroponics in an illuminated growth chamber with or without seed inoculation of bradyrhizobia, and in the absence or presence of nitrate in the culture solution. When the plants were grown without inoculation, the total dry weight of all mutant lines was not different statistically from Williams, both in the absence and presence of nitrate. When they were grown with inoculation of bradyrhizobia, however, the total dry weight of each mutant line was significantly lower than that of Williams, both in the absence and presence of nitrate. These results indicate that the reduced accumulation of total dry matter of hypernodulation mutant lines compared with the wild type may be a secondary effect passively resulting from the large number of nodules, while the hypernodulation trait is a primary effect of the mutated gene. When the plants were grown with inoculation, the nodule number was decreased by the presence of nitrate in Williams, NOD1-3 and NOD2-4, but not in NOD3-7. NOD3-7 may be the most tolerant to nitrate inhibition of nodulation among the NOD mutant lines. In contrast, leaf growth of NOD3-7 and NOD1-3 was different from the wild type; the expanded leaf was smaller, but the leaf emergence rate was faster compared with Williams under all conditions. This indicates that NOD3-7 and NOD1-3 might decrease the ability for leaf expansion or may have a faster leaf emergence rate.  相似文献   

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3.
We report two new syntheses of (2S,3R)-2-(2Z,5Z-octadienyl)-3-nonyloxirane, the main sex pheromone component of the pink moth, Lymantria mathura. The key step in the first route was the construction of (Z,Z)-1-bromo-1,4-heptadiene (6), which was coupled in the final step with 2-iodomethyl-3-nonyloxirane 4 via a Grignard reaction. The second approach employed alkylation of 1,4-heptadiynyllithium with epoxy triflates 7 in ether/hexane and provided the pheromone in >/=37% overall yield from alcohol 2. The 4:1 ratio of pheromone enantiomers, reportedly the most attractive to pink moth males, can be directly crafted from appropriately selected Sharpless asymmetric epoxidation conditions.  相似文献   

4.
采用耗竭法,研究了婆婆纳、离子草与小花糖芥三种麦田常见杂草吸收NO3-、H2PO4-、K+的动力学差异。试验结果表明:在吸收NO3-、H2PO4-、K+时,婆婆纳的Vm ax值要显著高于其它两种杂草;在吸收H2PO4-时,离子草的Km值要显著低于其它两种杂草;而在吸收K+时,却是小花糖芥的Km值最低。从而说明:三种杂草中,婆婆纳最能适应高N、P、K养分条件,离子草最能适应低P养分条件,而小花糖芥则最能适应低K养分条件。  相似文献   

5.
An ultrahigh-performance liquid chromatography (UHPLC) tandem mass spectrometric (MS/MS) method was developed for the simultaneous quantification of 2-acetyl-4-tetrahydroxybutylimidazole (THI), 2- and 4-methylimidazoles (2-MI and 4-MI), and 5-hydroxymethylfurfural (HMF) in beverage samples. A C30 reversed-phase column was used in this method, providing sufficient retention and total resolution for all targeted analytes, with an MS/MS instrument operated in selected reaction monitoring (SRM) mode for sensitive and selective detection using isotope-labeled 4-methyl-d(3)-imidazole (4-MI-d(3)) as the internal standard (IS). This method demonstrates lower limit of quantification (LLOQ) at 1 ng/mL and coefficient of determination (r(2)) >0.999 for each analyte with a calibration range established from 1 to 500 ng/mL. This method also demonstrates excellent quantification accuracy (84.6-105% at 5 ng/mL, n = 7), precision (RSD < 7% at 5 ng/mL, n = 7), and recovery (88.8-99.5% at 10, 100, and 200 ng/mL, n = 3). Seventeen carbonated beverage samples were tested (n = 2) in this study including 13 dark-colored beverage samples with different flavors and varieties and 4 light-colored beverage samples. Three target analytes were quantified in these samples with concentrations in the range from 284 to 644 ng/mL for 4-MI and from 706 to 4940 ng/mL for HMF. THI was detected in only one sample at 6.35 ng/mL.  相似文献   

6.
7.
Synthesis of some new substituted [3-(3-chloro-4-fluorophenyl)-2-oxo-3,4-dihydro-2H-2lambda(5)-benzo[e][1,3,2]oxazaphosphinin-2-yl]-(aryl/alkyl)methanols (7a-k) based on the Pudovick reaction was accomplished in the presence of niobium pentoxide (Nb(2)O(5)) without using an external chiral ligand. Nb(2)O(5) appears to form the metal complex intermediate catalyst system (6) by reacting with 3-(3-chloro-4-fluoro-phenyl)-3,4-dihydrobenzo[e][1,3,2]oxazaphosphinine-2-oxide (4), which not only directs the Pudovick addition reactions of aldehyde but also increases the yields and purity of the products. These compounds exhibited a lethal effect on whip smut of sugarcane and were degraded in the environment in the presence of bacteria and fungi to nontoxic phosphate residues that act as possible plant nutrients. Thus, a new class of benzooxazaphosphininyl methanol derivatives that act in synergy both as antipathogens and as plant nutrients in the environment have been discovered.  相似文献   

8.
本文介绍了采用电导频散装置测量分别含有10-4mol/L HCl、5×10-5mol/LH2SO4和10-4mol/L H3PO4的黄棕壤、棕壤、黑土和砖红壤悬液(20-30g/kg)的电导频散曲线,频散曲线上均呈现频率范围相当宽的坪区.频散曲线的特性分析结果表明,黄棕壤和棕壤在3种酸溶液中的始散频率(0.6-1kHz)低于黑土悬液(16-28kHz),而砖红壤的始散频率最高(25-47kHz);Cl-、SO2-4和H2PO-4离子与4种土壤的相对亲合力(REC1.5/REC2-1)顺序为Cl-<SO2-4<H2PO-4,在不同土壤之间的顺序则随酸溶液而异.  相似文献   

9.
The photodegradation of 1-(2-chlorobenzoyl)-3-(4-chlorophenyl) urea in simulated air, methanol, dioxane, hexane, and water, with a xenon lamp as light source, was studied. The rate constants and half-lives of this compound in various media under nitrogen or oxygen were determined. The photoreaction products were analyzed with HPLC-UV, GC-MS, and direct probe MS and found to have some differences in different cases. With (32)P postlabeling DNA adduct formation experiments, one of the main products, 2-chorobenzamide, was found to be able to form a DNA adduct.  相似文献   

10.
On single oral administration of (14)C-S-53482 [7-fluoro-6-(3,4,5, 6-tetrahydrophthalimido)-4-(2-propynyl)-2H-1,4-benzoxazin-3( 4H)-one, Flumioxazin] labeled at the 1- and 2-positions of tetrahydrophthaloyl group to rats at 1 (low dose) or 100 (high dose) mg/kg, the radiocarbon was almost completely eliminated within 7 days after administration in both groups with generally very low residual (14)C tissue levels. The predominant excretion route was via the feces. The major fecal and urinary metabolites involved reduction or sulfonic acid addition reactions at the 1,2-double bond of the 3,4,5,6-tetrahydrophthalimide moiety and hydroxylation of the cyclohexene or cyclohexane ring. One urinary and four fecal metabolites were identified using chromatographic techniques and spectroanalyses (NMR and MS). Three of five identified metabolites were unique forms, reduced at the 1,2-double bond of the 3,4,5, 6-tetrahydrophthalimide moiety. On the basis of the metabolites identified in this study, the metabolic pathways of S-53482 in rats are proposed. To specify tissues forming reduced metabolites, an in vitro study was conducted. Reduction was found to take place in red blood cells.  相似文献   

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Wheat (Triticum aestivum L.) has been found to possess allelopathic potential and studies have been conduced to apply wheat allelopathy for biological weed control. 2,4-Dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one (DIBOA) is a common product found in wheat, corn, and rye exudates and it can be released to the environment by that way. In this report, the stability of DIBOA is studied in two soils from crop lands of wheat cv. Astron and cv. Ritmo. These varieties were selected by their concentrations of DIBOA and 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA) from aerial parts and by the bioactivities of their aqueous extracts in the growth of wheat coleoptile sections. The degradation rate of DIBOA in these soils was measured in laboratory tests during 90 h by high-pressure liquid chromatography methods. These analyses demonstrate that DIBOA was transformed primarily into 2-benzoxazolinone (BOA). This transformation was similar in both soil types with an average half-life of 43 h. The degradation studies for BOA show its biotransformation to 2-aminophenoxazin-3-one (APO) with a half-life of 2.5 days. Therefore, BOA is an intermediate product in the biotransformation from DIBOA to APO in these wheat crop soils and is consistent with previous findings. APO was not degraded after three months in soil, suggesting that its degradation rate in soil is very slow.  相似文献   

13.
14.
Parallel synthesis was applied to prepare a series of 3-(acetylthio)-2-alkyl alkanals by Michael addition of thioacetic acid under alkaline conditions to alpha,beta-unsaturated 2-alkyl-substituted aldehydes, which were obtained by aldol condensation of the corresponding primary aldehydes as starting materials. The target compounds were characterized in terms of GC, MS, and NMR data. The sensory properties of the odorants, such as odor quality and odor detection threshold value, were determined with a trained panel. Structure-activity relationships are discussed, suggesting that the 1,3-oxygen-sulfur functionality, required for the "olfactophore" of tropical/vegetable notes, can further be extended to the acetylthio derivatives.  相似文献   

15.
It has been reported that 1-(2-chlorobenzoyl)-3-(4-chlorophenyl) urea (CCU), an insect growth regulator, has no measurable toxicity to nontarget organisms and is essentially harmless to humans. However, one of its degradation products, 2-chlorobenzamide (CBA), is suspected of being a carcinogen. Therefore, the maximum concentration of CBA formed and the dynamics of its formation need to be given careful attention after CCU is used in the field. This paper describes the degradation of CCU to form CBA in three different water systems (distilled water, spring water, and simulated seawater) and the effects of temperature on the dynamics of CBA formation. The results indicate that the maximum level of CBA concentration is different in the different systems (highest in spring water) and that the temperature has a significant impact on the process (higher temperature leads to higher and earlier peak of CBA concentration). The maximum concentration of CBA after application of CCU was approximately 3.8% of the initial concentration of CCU at 35 degrees C in distilled water, and 2.4% in spring water at 25 degrees C.  相似文献   

16.
Thiamin hydrochloride was thermally degraded in phosphate buffer (pH 6.5) at 110 degrees C for 2 h. A major decomposition product was isolated by column chromatography and structurally identified by spectrometric techniques ((1)H NMR, (13)C NMR, 2D NMR, and MS) as 2-methyl-4-amino-5-(2-methyl-3-furylthiomethyl)pyrimidine (MAMP). The possible formation pathway of MAMP was studied using two model systems. It is proposed that MAMP is formed by nucleophilic attack of 2-methyl-3-furanthiol on the thiamin.  相似文献   

17.
The suitability of [2,2,4,4-(2)H(4)]sarsasapogenone (1b), [2,2,4,4-(2)H(4)]sarsasapogenin (2b), and [2,2,4,4-(2)H(4)]episarsasapogenin (3b) as isotopically labeled dosing substrates to determine the levels of free and conjugated sapogenins present in feces from sheep grazing saponin-containing plants implicated in the development of ovine heptagenous photosentization diseases was investigated. A 1:4 mixture of [2,2,4,4-(2)H(4)]sarsasapogenin (2b) and [2,2,4,4-(2)H(4)]episarsasapogenin (3b), obtained by reduction of [2,2,4,4-(2)H(4)]sarsasapogenone (1b), was found to retain 94% of incorporated deuterium, when dosed to one sheep. The recovery of the dosed mixture of genins 2b and 3b was calculated to be 85%. Considerable loss of deuterium and a lower recovery of genin material were observed when [2,2,4,4-(2)H(4)]sarsasapogenone (1b) was dosed.  相似文献   

18.
The degradation of 2, 4-D, 2, 4, 5-T, and picloram in two Philippine soils was investigated under upland and flooded (submerged) conditions. These herbicides degraded in both upland and flooded Maahas clay and Luisiana clay soils. The rate of degradation of the herbicides was more rapid in the Maahas clay soil than in the Luisiana clay soil. Among the three herbicides, 2, 4-D was the least persistent and picloram was the most persistent in both soils under both submerged and upland conditions. 2, 4, 5-T degraded more actively in the two Philippine soils in this study than studies previously reported in the available literature. The fact that both the 2, 4-D and 2, 4, 5-T did not degrade in sterilized soils during the incubation period suggests that the degradation is due to the microbial activity in the soils.  相似文献   

19.
酸雨中的SO4^2-和NO3^-等阴离子在土壤中迁移时会引起大量的盐基离子淋溶,导致土壤退化。用室内土柱模拟SO4^2-和NO3^-在红壤旱地各土层中的垂直穿透状况,并用Hydrus-1D模型对试验结果进行了拟合和预测。结果表明,N05在红壤各层中的穿透速度较快,其中在耕作层的穿透曲线峰值最高,C/C0达到0.39,峰值高低顺序依次为:耕作层〉母质层〉淋溶层〉犁底层。SO4^2-在土柱中的穿透速度远低于NO3^-,穿透曲线有明显的拖尾现象。其在各土层的穿透时间依次为:母质层〉犁底层〉淋溶层〉耕作层;而其峰值高低顺序依次为:耕作层〉淋溶层〉母质层〉犁底层,最高点耕作层的顶点C/C0仅为0.22。用Hydrus-1D模型对试验结果进行模拟,所得的SO4^2-和NO3^-穿透土壤的浓度模拟值与其实测值均呈极显著的正相关关系。利用数学模拟获得了饱和导水率和垂直扩散率等溶质运移参数,并预测了研究区酸雨后SO4^2-和NO3^-在红壤耕层的迁移状况,表明SO4^2-会在酸雨结束后持续淋溶,从而影响土壤中Ca、Mg等盐基离子的淋失。  相似文献   

20.
1-(2-chlorobenzoyl)-3-(4-chlorophenyl)urea (CCU), a new analogue of diflubenuron and PH-6038, has been widely used in agriculture and forestry as a molt-inhibiting hormone insecticide which was developed in China. 2-Chlorobenzamide, a main degradation product of CCU in the environment, has been identified as a potential carcinogen, so the content of 2-chlorobenzamide from the breakup of CCU will directly affect the environmental safety of CCU. In this paper we describe a simple, rapid, and convenient prediction model for predicting the level and time of occurrence of the peak concentration of 2-chlorobenzamide in the hydrolysis of CCU verified by experimental data. The time for reaching the peak concentration of 2-chlorobenzamide (tm) at 25 degrees C and pH 6 is 13.5 d, and the maximum concentration of 2-chlorobenzamide (ym) is 3.2% of the initial concentration of CCU according to the results from the prediction model. These results are similar to the real values from the experiments, which are 22 d and 1.6% of the initial concentration of CCU, respectively. The difference between the values of the prediction and experiment is discussed, and it is demonstrated that the predicting model is highly credible.  相似文献   

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