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1.
选用10个具有代表性辣椒品种(系),于人工气候室内分别在正常和高温高湿条件下,研究了现蕾期辣椒抗氧化系统生理生化性状的变化以及不同品种(系)的抗氧化性差异。结果表明:10个辣椒品种(系)抗坏血酸(AsA)、花青素含量下降,而谷胱甘肽(GSH)、花色苷含量增加;超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、苯丙氨酸解氨酶(PAL)4个酶活性一致增强。根据8个生理生化指标的相对值,通过坐标综合评定法对活性氧的抑制和清除进行分析,抗氧化剂类的贡献大于抗氧化酶类;系统聚类法将10个辣椒品种(系)的抗氧化性强弱分为3类:06591、115-5-5-12-9-1-2、B04-99-5-1-1-2、06597、06590为强抗氧化性品种(系);B04-51-4-2-1-2-1和43-5-1-1-1为中等抗氧化性品种(系);06592、B04-114-1-1-1-1-1、B04-512-4-1(系)为弱抗氧化性品种。  相似文献   

2.
Procyanidin dimers and trimers, needed as reference compounds for biological studies, have been synthesized from various natural sources using a semisynthetic approach and purified by high-speed countercurrent chromatography (HSCCC). In the past, it has been difficult to elucidate the structure of these compounds, especially the determination of the interflavanoid bond. Here, the structure of two B-type procyanidin dimers, with (+)-catechin ((+)-C) in the upper unit, and eight C-type procyanidin trimers, with (-)-epicatechin ((-)-EC) in the upper unit, have been elucidated using low-temperature (1)H NMR spectroscopy, as well as circular dichroism (CD) spectroscopy. This is the first time NOE interactions have been used to characterize the interflavanoid linkage in underivatized procyanidin trimers. Complete analyses of procyanidin C1 (-)-EC-4β→8-(-)-EC-4β→8-(-)-EC, (-)-EC-4β→8-(-)-EC-4β→8-(+)-C, (-)-EC-4β→6-(-)-EC-4β→8-(-)-EC, (-)-EC-4β→6-(-)-EC-4β→8-(+)-C, (-)-EC-4β→8-(-)-EC-4β→6-(-)-EC, (-)-EC-4β→8-(-)-EC-4β→6-(+)-C, (-)-EC-4β→8-(+)-C-4α→8-(-)-EC, procyanidin C4 (-)-EC-4β→8-(+)-C-4α→8-(+)-C, and procyanidin dimers B6 (+)-C-4α→6-(+)-C and B8 (+)-C-4α→6-(-)-EC are presented.  相似文献   

3.
Maple syrup is made by boiling the sap collected from certain maple ( Acer ) species. During this process, phytochemicals naturally present in tree sap are concentrated in maple syrup. Twenty-three phytochemicals from a butanol extract of Canadian maple syrup (MS-BuOH) had previously been reported; this paper reports the isolation and identification of 30 additional compounds (1-30) from its ethyl acetate extract (MS-EtOAc) not previously reported from MS-BuOH. Of these, 4 compounds are new (1-3, 18) and 20 compounds (4-7, 10-12, 14-17, 19, 20, 22-24, 26, and 28-30) are being reported from maple syrup for the first time. The new compounds include 3 lignans and 1 phenylpropanoid: 5-(3″,4″-dimethoxyphenyl)-3-hydroxy-3-(4'-hydroxy-3'-methoxybenzyl)-4-(hydroxymethyl)dihydrofuran-2-one (1), (erythro,erythro)-1-[4-[2-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(hydroxymethyl)ethoxy]-3,5-dimethoxyphenyl]-1,2,3-propanetriol (2), (erythro,threo)-1-[4-[2-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(hydroxymethyl)ethoxy]-3,5-dimethoxyphenyl]-1,2,3-propanetriol (3), and 2,3-dihydroxy-1-(3,4- dihydroxyphenyl)-1-propanone (18), respectively. In addition, 25 other phenolic compounds were isolated including (threo,erythro)-1-[4-[(2-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(hydroxymethyl)ethoxy]-3-methoxyphenyl]-1,2,3-propanetriol (4), (threo,threo)-1-[4-[(2-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(hydroxymethyl)ethoxy]-3-methoxyphenyl]-1,2,3-propanetriol (5), threo-guaiacylglycerol-β-O-4'-dihydroconiferyl alcohol (6), erythro-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2,6-dimethoxyphenoxy]-1,3-propanediol (7), 2-[4-[2,3-dihydro-3-(hydroxymethyl)-5-(3-hydroxypropyl)-7-methoxy-2-benzofuranyl]-2,6-dimethoxyphenoxy]-1-(4-hydroxy-3-methoxyphenyl)-1,3-propanediol (8), acernikol (9), leptolepisol D (10), buddlenol E (11), (1S,2R)-2-[2,6-dimethoxy-4-[(1S,3aR,4S,6aR)-tetrahydro-4-(4-hydroxy-3,5-dimethoxyphenyl)-1H,3H-furo[3,4-c]furan-1-yl]phenoxy]-1-(4-hydroxy-3-methoxyphenyl)-1,3-propanediol (12), syringaresinol (13), isolariciresinol (14), icariside E4 (15), sakuraresinol (16), 1,2-diguaiacyl-1,3-propanediol (17), 2,3-dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone (19), 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)propan-1-one (20), dihydroconiferyl alcohol (21), 4-acetylcatechol (22), 3',4',5'-trihydroxyacetophenone (23), 3,4-dihydroxy-2-methylbenzaldehyde (24), protocatechuic acid (25), 4-(dimethoxymethyl)pyrocatechol (26), tyrosol (27), isofraxidin (28), and 4-hydroxycatechol (29). One sesquiterpene, phaseic acid (30), which is a known metabolite of the phytohormone abscisic acid, was also isolated from MS-EtOAc. The antioxidant activities of MS-EtOAc (IC(50) = 75.5 μg/mL) and the pure isolates (IC(50) ca. 68-3000 μM) were comparable to that of vitamin C (IC(50) = 40 μM) and the synthetic commercial antioxidant butylated hydroxytoluene (IC(50) = 3000 μM), in the diphenylpicrylhydrazyl radical scavenging assay. The current study advances scientific knowledge of maple syrup constituents and suggests that these diverse phytochemicals may impart potential health benefits to this natural sweetener.  相似文献   

4.
龙洞沟泥石流滩地剖面结构和土壤物理结构较差 ,砂石化现象严重 ;土壤微团聚体数量较少 ,粒级间比例不合理 ;土壤养分除全钾极丰富外 ,其它大部分养分都处于缺乏或极缺状态。通过开发利用 ,其表土层结构特性和养分状况得到显著改善 :砾石含量由 63 .0 3～ 70 .78%减少到 3 9.66～ 57.62 % ,粉粒和粘粒含量由 2 6.75～ 3 1.89%增加到 3 0 .54～41.93 % ;有机质由 7.1～ 10 .8gkg- 1提高到 15.8～ 2 6.9gkg- 1;全氮由 1.2 0～ 1.40gkg- 1提高到 1.50～ 1.93gkg- 1;全磷由0 .46～ 0 .57gkg- 1提高到 0 .48～ 0 .79gkg- 1;有效氮由 47.2 2～ 56.67mgkg- 1提高到 79.3 9～ 119.46mgkg- 1;有效磷由 2 .2 1～ 4.69mgkg- 1提高到 5.58mgkg- 1;有效钾由 2 9.84～ 40 .3 6mgkg- 1提高到 51.89～ 89.3 6mgkg- 1。不同利用模式的改良作用不同 ,依次为 :菜园地 >苹果 +蔬菜地 >苹果园地 >苹果 +花椒地 >花椒园地 >荒滩地  相似文献   

5.
A semisynthetic approach for the strategic formation of various procyanidins has been developed. Procyanidin-rich grape seed extracts were reacted with flavan-3-ols under acid catalysis. The reaction enables the formation of dimeric procyanidins and the elimination of higher oligomeric and polymeric procyanidins through degradation. An easy and fast method for the isolation of large amounts of procyanidins after semisynthetic formation by high-speed countercurrent chromatography is presented. Dimeric procyanidins (B1, B2, B3, B4, B5, and B7) were obtained and isolated. Furthermore, galloylated dimeric procyanidins [(-)-epicatechin-3- O-gallate-4beta-->8-(+)-catechin, (-)-epicatechin-3- O-gallate-4beta-->8-(-)-epicatechin, (-)-epicatechin-3- O-gallate-4beta-->6-(-)-epicatechin, and (-)-epicatechin-4beta-->8-(-)-epicatechin-3- O-gallate], as well as trimeric procyanidins [C1, (-)-epicatechin-4beta-->6-(-)-epicatechin-4beta-->8-(-)-epicatechin, and (-)-epicatechin-4beta-->6-(-)-epicatechin-4beta-->6-(+)-catechin] were obtained and isolated as side products. This approach also afforded gambiriins A1 and A2, which were all isolated and unambiguously identified, and the novel 3-(2,4,6-trihydroxyphenyl)-1-(3,4-dihydroxyphenyl)-propan-2-ol-1beta-->8-(-)-epicatechin (gambiriin A4).  相似文献   

6.
水稻苗期耐低磷基因型差异研究   总被引：5，自引：0，他引：5  
采用难溶性磷酸盐Ca3 (PO4) 2 液相控释方法试验研究不同水稻品种 (系 )苗期耐低P基因型差异结果表明 ,各水稻基因型耐低P胁迫能力存在极显著差异 ,其中“汕优 6 3”、“IR74”、“汕优 16 1”、“IR70 6 17 4B B19 2”、“IR6 4”5个品种 (组合 )耐低P能力最强 ;“IR70 6 5 1 3B 3 2 2 2”、“IR71331 2B 2 1”、“南川”、“IR71379 2B 10 2 3 1”和“IR72 4 13 3R 2 6 2”5个品种 (系 )对低P胁迫较敏感 ;而“IR73384 11 7 8 3 2 3 3 3”、“IR73382 111 9 19 19 2 3 1 2”、“IR72 4 17 3R 6 2”、“IR36”、“IR72 4 17 3R 8 3”和“IR72 4 12 3R 11 3”6个品种 (系 )P效率则属中间型。  相似文献   

7.
LC/MS analysis of cyclohexanedione oxime herbicides in water   总被引：1，自引：0，他引：1  
A multiresidue method for the determination of alloxydim (methyl 2, 2-dimethyl-4, 6-dioxo-5-[1-[2-propenyloxy)amino]butylidene]cyclohexanec arb oxylate), clethodim (E, E)-(+/-)-2-[1-[[3-chloro-2-propenyl)oxy]imino]propyl]-5-[2-(ethylthio )propyl]-3-hydroxy-2-cyclohexen-1-one), sethoxydim ((+/-)-2-[1-(ethoxyimino)butyl]-5-[2-ethylthio)propyl]-3-hydroxy-2 -cy clohexen-1-one), and two metabolites, clethodim sulfoxide ((E, E)-(+/-)-2-[1-[[3-chloro-2-propenyl)oxy]imino]propyl]-5-[2-(ethylsulf inyl)propyl]-3-hydroxy-2-cyclohexen-1-one) and sethoxydim sulfoxide ((+/-)-2-[1-(ethoxyimino)butyl]-5-[2-ethylsulfinyl)propyl]-3 -hydroxy- 2-cyclohexen-1-one), in water by high-performance liquid chromatography/electrospray/mass spectrometry (LC/ES/MS) is reported. River water and distilled water were spiked at 0.08 and 0.8 microgram L(-1) with all three herbicides, which were then extracted from the water by C(18)-SPE (SPE = solid-phase extraction). The herbicides and metabolites were quantified and confirmed using selected ion monitoring. The percent recoveries of the herbicides from water spiked at 0.8 microgram L(-1) were as follows: alloxydim, 117 +/- 11%; clethodim, 96 +/- 14%; sethoxydim, 89 +/- 13%. There was no evidence of oxidation of clethodim and sethoxydim during the extraction to their respective sulfoxides. The limit of quantitation was <0.1 microgram L(-1). We have shown that we can analyze and confirm three cyclohexanedione oxime herbicides and two metabolites in water by LC/ES/MS. This multiresidue method should also be appropriate for other cyclohexanedione oximes.  相似文献   

8.
山东石灰性潮土、褐土无机磷的形态、转化和有效性   总被引：2，自引：0，他引：2  
应用蒋柏藩、顾益初提出的“石灰性土壤无机磷分级方法”研究了山东省石灰性潮土、褐土、砂姜黑土的无机磷组成、转化和对作物的有效性。结果表明,石灰性土壤无机磷中以Ca10-P占绝对优势,约占无机磷总量的54.52％,其次为O-P,占21.55％,Al-P、Fe-P,Ca8-P分别占5～10％,Ca2-P只有1.08％;在土壤剖面中各级无机磷皆随剖面深度增加而减少;水溶性磷肥施入土壤后,在作物一个生长季节内主要转化成Ca8-P,占全部转化量的50～70％,其次是Ca2-P,占10～30％,Al-P占11～13％,Fe-P很少,占5％左右;在各级无机磷中对作物有效性顺序是Ca2-P>Al-P、Fe-P>Ca8-P>O-P、Ca10-P。  相似文献   

9.
Antioxidative compounds were isolated from the methanol extract of fresh rhizome of smaller galanga (Alpinia officinarum Hance). Seven phenylpropanoids (1-7) were finally obtained by reversed-phase HPLC, and their structures were elucidated by MS and NMR analyses. They comprised the two known compounds, (E)-p-coumaryl alcohol gamma-O-methyl ether (1) and (E)-p-coumaryl alcohol (6), and the five novel compounds, stereoisomers of (4E)-1,5-bis(4-hydroxyphenyl)-1-methoxy-2-(methoxymethyl)-4-pentene (2a and 2b), stereoisomers of (4E)-1,5-bis(4-hydroxyphenyl)-1-ethoxy-2-(methoxymethyl)-4-pentene (3a and 3b), (4E)-1,5-bis(4-hydroxyphenyl)-1-[(2E)-3-(4-acetoxyphenyl)-2-propenoxy]-2-(methoxymethyl)-4-pentene (4), (4E)-1,5-bis(4-hydroxyphenyl)-2-(methoxymethyl)-4-penten-1-ol (5), and (4E)-1,5-bis(4-hydroxyphenyl)-2-(hydroxymethyl)-4-penten-1-ol (7). Compounds 1-7 were detected for the first time as constituents of galanga rhizomes and exhibited antioxidative activities against the autoxidation of methyl linoleate in bulk phase.  相似文献   

10.
The sorption efficiency of indigenous rice (Oryza sativa) bran for the removal of organics, that is, benzene, toluene, ethylbenzene, and cumene (BTEC), from aqueous solutions has been studied. The sorption of BTEC by rice bran is observed over a wide pH range of 1-10, indicating its high applicability to remove these organics from various industrial effluents. Rice bran effectively adsorbs BTEC of 10 microg mL(-1) sorbate concentration from water at temperatures of 283-323 +/- 2 K. The effect of pH, agitation time between solid and liquid phases, sorbent dose, its particle size, and temperature on the sorption of BTEC onto rice bran has been studied. The pore area and average pore diameter of rice bran by BET method are found to be 19 +/- 0.7 m(2) g(-1) and 52.8 +/- 1.3 nm. The rice bran exhibits appreciable sorption of the order of 85 +/- 3.5, 91 +/- 1.8, 94 +/- 1.4, and 96 +/- 1.2% for 10 microg mL(-1) concentration of benzene, toluene, ethylbenzene, and cumene, respectively, in 60 min of agitation time using 0.1 g of rice bran at pH 6 and 303 K. The sorption data follow Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) models. Sorption capacities have been computed for BTEC by Freundlich (32 +/- 3, 61 +/- 14, 123 +/- 28, and 142 +/- 37 m mol g(-1)), Langmuir (6.6 +/- 0.1, 7.5 +/- 0.13, 9.5 +/- 0.22, and 9.4 +/- 0.18 m mol g(-1)), and D-R isotherms (11 +/- 0.5, 16 +/- 1.3, 30 +/- 2.2, and 33 +/- 2.5 m mol g(-1)), respectively. The Lagergren equation is employed for the kinetics of the sorption of BTEC onto rice bran and first-order rate constants (0.03 +/- 0.002, 0.04 +/- 0.003, 0.04 +/- 0.003, and 0.05 +/- 0.004 min(-1)) have been computed for BTEC at their concentration of 100 mug mL(-1) at 303 K. Studies on the variation of sorption with temperatures (283-323 K) at 100 mug mL(-1) sorbate concentration gave thermodynamic constants DeltaH (kJ mol(-1)), DeltaG (kJ mol(-1)), and DeltaS (J mol(-1) K(-1)). The results indicate that the sorption of organics onto rice bran is exothermic and spontaneous in nature under the optimized experimental conditions selected. This sorbent has been used successfully to accumulate and then to determine benzene, toluene, and ethylbenzene in wastewater sample.  相似文献   

11.
Bioactivity-guided fractionation of black bean (Phaseolus vulgaris) seed coats was used to determine the chemical identity of bioactive constituents, which showed potent antiproliferative and antioxidative activities. Twenty-four compounds including 12 triterpenoids, 7 flavonoids, and 5 other phytochemicals were isolated using gradient solvent fractionation, silica gel and ODS columns, and semipreparative and preparative HPLC. Their chemical structures were identified using MS, NMR, and X-ray diffraction analysis. Antiproliferative activities of isolated compounds against Caco-2 human colon cancer cells, HepG2 human liver cancer cells, and MCF-7 human breast cancer cells were evaluated. Among the compounds isolated, compounds 1, 2, 6, 7, 8, 13, 14, 15, 16, 19, and 20 showed potent inhibitory activities against the proliferation of HepG2 cells, with EC50 values of 238.8 +/- 19.2, 120.6 +/- 7.3, 94.4 +/- 3.4, 98.9 +/- 3.3, 32.1 +/- 6.3, 306.4 +/- 131.3, 156.9 +/- 11.8, 410.3 +/- 17.4, 435.9 +/- 47.7, 202.3 +/- 42.9, and 779.3 +/- 37.4 microM, respectively. Compounds 1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 14, 15, 19, and 20 showed potent antiproliferative activities against Caco-2 cell growth, with EC50 values of 179.9 +/- 16.9, 128.8 +/- 11.6, 197.8 +/- 4.2, 105.9 +/- 4.7, 13.9 +/- 2.8, 35.1 +/- 2.9, 31.2 +/- 0.5, 71.1 +/- 11.9, 40.8 +/- 4.1, 55.7 +/- 8.1, 299.8 +/- 17.3, 533.3 +/- 126.0, 291.2 +/- 1.0, and 717.2 +/- 104.8 microM, respectively. Compounds 5, 7, 8, 9, 11, 19, 20 showed potent antiproliferative activities against MCF-7 cell growth in a dose-dependent manner, with EC50 values of 129.4 +/- 9.0, 79.5 +/- 1.0, 140.1 +/- 31.8, 119.0 +/- 7.2, 84.6 +/- 1.7, 186.6 +/- 21.1, and 1308 +/- 69.9 microM, respectively. Six flavonoids (compounds 14-19) showed potent antioxidant activity. These results showed the phytochemical extracts of black bean seed coats have potent antioxidant and antiproliferative activities.  相似文献   

12.
Covalently cross-linked proteins are among the major modifications caused by the advanced Maillard reaction. So far, the chemical nature of these aggregates is largely unknown. Investigations are reported on the isolation of 6-[2-[[(4S)-4-amino-4-carboxybutyl]amino]-6,7-dihydroxy-6,7-dihydroimidazo[4,5-b]azepin-4(5H)-yl]-L-norleucine (10) and N-acetyl-6-[(6R,7R)-2-[[4-(acetylamino)-4-carboxybutyl]amino]-6,7,8a-trihydroxy-6,7,8,8a-tetrahydroimidazo[4,5-b]azepin-4(5H)-yl]-L-norleucine (12) formed by oxidation of the major Maillard cross-link glucosepane 1. Independent synthesis and unequivocal structural characterization are given for 10 and 12. Spiro cross-links, representing a new class of glycoxidation products, were obtained by dehydrogenation of the amino imidazolinimine compounds N6-[2-[[(4S)-4-ammonio-5-oxido-5-oxopentyl]amino]-5-[(2S,3R)-2,3,4-trihydroxybutyl]-3,5-dihydro-4H-imidazol-4-ylidene]-L-lysinate (DOGDIC 2) and N6-[2-[[(4S)-4-ammonio-5-oxido-5-oxopentyl]amino]-5-[(2S)-2,3-dihydroxypropyl]-3,5-dihydro-4H-imidazol-4-ylidene]-L-lysinate (DOPDIC 3). These new oxidation products were synthesized, and their unambiguous structural elucidation proved the formation of the spiro imidazolimine structures N6-[(7R,8S)-2-[[(4S)-4-ammonio-5-oxido-5-oxopentyl]amino]-8-hydroxy-7-(hydroxymethyl)-6-oxa-1,3-diazaspiro[4.4]non-1-en-4-ylidene]-L-lysinate (16), N6-(8R,9S)-2-[(4S)-4-ammonio-5-oxido-5-oxopentyl]amino]-8,9-dihydroxy-6-oxa-1,3-diazaspiro[4.5]dec-1-en-4-ylidene)-L-lysinate (19), and N6-[(8S)-2-[(4-amino-4-carboxybutyl)amino]-8-hydroxy-6-oxa-1,3-diazaspiro[4.4]non-1-en-4-ylidene]-L-lysinate (18), respectively. It was shown that reaction of the imidazolinone 15 led to the formation of spiro imidazolones, structurally analogous to 16 and 19.  相似文献   

13.
秸秆还田下氮肥运筹对白土田水稻产量和氮吸收利用的影响   总被引：16，自引：2，他引：14  
【目的】研究小麦秸秆直接还田条件下不同氮肥基追比例运筹方式对白土稻田水稻产量和氮素吸收利用的影响, 为华中低产白土稻田水稻合理施肥提供科学依据。【方法】设置2种小麦秸秆还田量(0和3000 kg/hm2)及3种氮肥基肥-分蘖肥-穗肥施用比例(80-0-20、 60-20-20 和40-30-30)和不施氮的对照, 共7个处理, 分别为N80-0-20、 N60-20-20、 N40-30-30、 N80-0-20+S、 N60-20-20+S、 N40-30-30+S和CK。水稻收获期采集代表性样品考察水稻产量结构性状, 同时测定水稻籽粒和秸秆产量, 分析籽粒和秸秆氮素含量, 计算水稻氮素吸收量和氮肥利用效率。【结果】基肥-分蘖肥-穗肥施用比例60-20-20的处理水稻籽粒产量最高, 两年试验较不施分蘖肥的对照分别增产9.4%~12.9%和7.4%~8.9%。实施小麦秸秆直接还田后, 水稻籽粒产量较不施秸秆的对照分别提高10.2%~23.4%和0.8%~5.5%。不施秸秆条件下, 基-蘖-穗肥施用比例60-20-20的处理水稻籽粒含氮量最高, 较不施氮的对照提高11.3%, 而秸秆含N量随中后期追肥比例的加大而提高。秸秆还田条件下, 氮肥后移能明显提高水稻籽粒和秸秆含氮量。水稻籽粒氮素吸收量, 基-蘖-穗肥比例60-20-20处理最多, 2011年较对照N80-0-20分别增加13.7%和24.8%, 2012年提高14.5%和9.2%; 秸秆氮素积累量则随中后期追肥用量的增加而增多, 基-蘖-穗肥比例40-30-30处理最多。不施秸秆条件下, 基-蘖-穗肥比例60-20-20的处理氮素干物质生产效率、 氮素稻谷生产效率、 氮收获指数均最高, 百公斤籽粒吸氮量最低。秸秆还田条件下, 氮素干物质生产效率和氮素稻谷生产效率均随中后期追肥量的增加而下降, 而百公斤籽粒吸氮量则最高。氮素农学效率、 氮肥回收利用率和偏生产力也是60-20-20比例的处理最高, 较对照N80-0-20农学效率分别提高4.90和2.44 kg籽粒/kg N, 氮肥利用率提高7.82和21.29个百分点, 偏生产力提高4.90和2.44个百分点。【结论】综合水稻产量、 氮素吸收量以及氮肥利用效率, 安徽省江淮丘陵低产白土地区, 小麦秸秆直接还田条件下, 单季中稻氮肥的基肥-分蘖肥-穗肥施用比例, 以60-20-20运筹方式较为适宜。  相似文献   

14.
为能更好地培育出适合会宁旱地农业区种植的抗逆性强、丰产性好的春小麦新品种,加快当地春小麦新品种利用和更新换代,在会宁半干旱春麦种植区对近年来选育出的9个旱地春小麦新品系进行了品比试验。结果表明,轮选07068-3-16生育期为100 d,较对照品种西旱2号早熟4 d;出苗率高,抗倒性强;丰产性优,较对照品种西旱2号增产9.06%,且产量差异达极显著水平。06083-7-6、06024-10-9抗逆性较强,成熟落黄好,籽粒饱满,色泽好,产量较高,均较对照品种西旱2号增产7.25%。综合考虑,轮选07068-3-16、06083-7-6,06024-10-9综合农艺性状表现优良,建议进入甘肃省旱地春小麦区域试验。  相似文献   

15.
Little is known about the metabolism of acetylenic (C&tbd1;C) compounds commonly used in the formulation of pesticides. To better understand the in vivo reactivity of this bond, we examined the metabolism of propargyl alcohol (PA), 2-propyn-1-ol, used extensively in the chemical industry. [1,2,3-(13)C, 2,3-(14)C]PA was administered orally to male Sprague-Dawley rats. Approximately 56% of the dose was excreted in urine by 96 h. Major metabolites were characterized, directly, in the whole urine by one- and two-dimensional (13)C NMR. To determine the complete structures of metabolites of PA, rat urine was also subjected to TLC followed by purification of separated TLC bands on HPLC. The purified metabolites were identified by (13)C NMR and mass spectrometry and by comparison with available synthetic standards. The proposed metabolic pathway involves oxidation of propargyl alcohol to 2-propynoic acid and further detoxification via glutathione conjugation to yield as final products: 3, 3-bis[(2-(acetylamino)-2-carboxyethyl)thio]-1-propanol, 3-(carboxymethylthio)-2-propenoic acid, 3-(methylsulfinyl)-2-(methylthio)-2-propenoic acid, 3-[[2-(acetylamino)-2-carboxyethyl]thio]-3-[(2-amino-2-carboxyethyl)t hio]-1-propanol and 3-[[2-(acetylamino)-2-carboxyethyl]sulfinyl]-3-[2-(acetylamino)-2-car boxyethyl]thio]-1-propanol. These unique metabolites have not been reported previously and represent the first example of multiple glutathione additions to the carbon-carbon triple bond.  相似文献   

16.
试验采用营养液培养、同位素示踪方法,研究了HCO3-同化物在缺Zn敏感（IR26）和耐性水稻品种（IR8192-31-2）体内运输和分配的差异。研究结果表明,HCO3-同化物从敏感品种根部向地上部运输较少,在根部积累较多,而耐性品种HCO3-同化物向地上部运输较多,速率较快,而在根部积累较少;施Zn促进敏感品种HCO3-同化物从根部向地上部的运输。敏感品种离体根吸收的HCO3-高于耐性品种,并且HCO3-同化物从根尖向伸长区迁移的速率高于耐性品种。以上结果表明HCO3-同化物运输和分配差异是不同水稻品种对缺锌敏感差异的重要机制之一。  相似文献   

17.
The dimethyl derivatives of imazaquin, imazapyr, imazmethapyr, imazethapyr, 2-[4,5 dihydro-1, 4-dimethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methoxymethyl- 3-pyridine carboxylic acid, 2-[4,5-dihydro-1,4 -dimethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-4-methyl benzoic acid, and 2-[4,5-dihydro-1,4-dimethyl-4-(1-methyl ethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl benzoic acid were prepared and fully characterized. The availability of these derivatives has led to the development of efficient and multiresidue gas chromatographic methods for trace level analysis of imidazolinone herbicides in matrixes such as water, soybean, and soil.  相似文献   

18.
MAP65-3是植物胞质分裂的重要调节因子。为探究水稻OsMAP65-3基因的功能,本研究采用CRISPR/Cas9技术对水稻中OsMAP65-3基因(OsMAP65-3.1和OsMAP65-3.2)进行编辑。针对每个基因各设计了2个不同的靶位点,并将OsMAP65-3.1与OsMAP65-3.2的靶位点放在同一个载体上,构建了CSMAP65-3A和CSMAP65-3B 2个双基因编辑载体。通过农杆菌介导的遗传转化分别获得17和21个植株,PCR鉴定阳性植株分别为16和20株。对T0代植株靶位点附近序列进行测序分析,结果表明OsMAP65-3s基因均被成功编辑,OsMAP65-3.1 2个位点编辑效率为17.50%和9.38%,OsMAP65-3.2 编辑效率为15.62%和45.00%;T0代已获得osmap65-3.2、osmap65-3.2/OsMAP65-3.1(+/-)和OsMAP65-3.2(+/-)/OsMAP65-3.1(+/-)材料。本研究为进一步创制OsMAP65-3s突变体,开展基因功能研究和水稻胞质分裂分子机制解析奠定了理论基础。  相似文献   

19.
The organochlorine pesticides are lipophilic and persistent and tend to accumulate in soils and growing plants. The contamination of growing plants occurs by adhesion of volatile substances from the air to the plant surface and by the migration of contaminants through xylem in inner ascendant transport. Persistent organochlorine pesticides (HCB, alpha,gamma-HCH, pp'DDE, op'DDT, pp'DDT) levels were determined in soils and rye plants. The aims of the study were the monitoring of organochlorine pesticide concentrations and the comparison of these levels among soil, rye straw, and rye grains. Fifty soil samples and 50 rye plant (50 straw and 50 grains) samples were taken. The GLC-ECD chromatographic results indicated the following contamination levels distributed among soil, straw, and grains: HCB (0.7-1.2-0.7 microg.kg(-1)), alpha-HCH (0.6-3.4-1.2 microg.kg(-1)), gamma-HCH (1.8-27.3-4.4 microg.kg(-1)), Sigma-HCH (2.5-30.7-5.6 microg.kg(-1)), pp'DDE (1.0-7.8-5.5 microg.kg(-1)), op'DDT (16.1-20.4-17.0 microg.kg(-1)), pp'DDT (38.0-41.7-49.6 microg.kg(-1)), and Sigma-DDT (54.2-63.2-72.1 microg.kg(-1)). The study verified the presence of organochlorine pesticides in the Mexican agricultural environment and their migration from soil to the growing rye plants. However, DDT has been banned since 1999 for sanitary reasons, and Lindane is applied only in some cases as a seed dresser. The determined organochlorine pesticide levels in rye plants are low, at residual levels that are below Codex Alimentarius Commission maximum residue limits.  相似文献   

20.
福建三明烟区土壤肥力状况的研究   总被引：19，自引：0，他引：19  
通过对三明烟区具有代表性的316个土壤样品的分析测定,结果表明:该烟区土壤pH平均为5.0;土壤养分的平均含量为:有机质27.0gkg-1、全氮1.4gkg-1、碱解氮142mgkg-1、全磷0.5gkg-1、速效磷24mgkg-1、全钾19.2gkg-1、缓效钾250mgkg-1、速效钾109mgkg-1、交换性钙726mgkg-1、交换性镁30mgkg-1、有效硫22mgkg-1、有效铁23.8mgkg-1、有效锰9.9mgkg-1、有效铜2.7mgkg-1、有效锌2.0mgkg-1、有效硼0.2mgkg-1、水溶性氯15.0mgkg-1。三明烟区土壤有机质含量普遍较高,pH偏低,全氮、碱解氮水平中等,适宜烤烟生长;部分土壤有效磷含量较高,应合理适量施用磷肥;速效钾普遍缺乏,应重视钾肥施用;土壤镁、硼营养明显不足,应增加镁,硼营养,在施用石灰调节土壤酸度的同时应避免影响烤烟对镁,硼的吸收;慎重施用氯肥。  相似文献   

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