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71.
72.
香蕉受枯萎病菌侵染后酚类物质含量的变化 总被引:1,自引:0,他引:1
对人工接种香蕉枯萎病菌Fusarium oxysporum f.sp.cubense后香蕉体内总酚及阿魏酸含量的变化进行了研究.结果表明:接种的和对照的香蕉体内的总酚和阿魏酸含量总体上都呈上升趋势,这可能是由于香蕉本身就是一类多酚植物,香蕉体内酚类物质含量随植株生长而增加的缘故.然而,接种的香蕉体内的总酚和阿魏酸含量明显高于对照的香蕉体内的总酚和阿魏酸含量,例如,接种WG5菌株28d后粉蕉的总酚和阿魏酸含量分别为546和74.8μg/mL,而对照的相应品种在同一时间的总酚和阿魏酸含量分别为184和68.6μg/mL,表明罹病香蕉体内高水平的酚类物质含量与香蕉枯萎病菌的侵染有关. 相似文献
73.
[目的]对吸收光谱严重重叠的邻苯二酚、间苯二酚、邻苯三酚和间苯三酚四组分体系同时测定方法进行研究.[方法]按正交设计表L9(34)配制9组不同浓度组成的邻苯二酚、间苯二酚、邻苯三酚和间苯三酚标准混合溶液,弱酸性条件下,波长240~290 nm,每隔1 nm测定四组分体系的吸光度,建立偏最小二乘法测定四组分的校正模型,同时测定模拟混合样和水样中四组分的含量.[结果]邻苯二酚、间苯二酚、邻苯三酚和间苯三酚四组分在模拟混合样中绝大部分分析结果的相对预报误差(RPEs)在允许范围内.[结论]偏最小二乘法测定邻苯二酚、间苯二酚、邻苯三酚和间苯三酚四组分,测量体系稳定,结果可靠,提供了一种新的测量途径. 相似文献
74.
75.
Francesco Giuffrida Giulia Graziani Vincenzo Fogliano Domenica Scuderi Daniela Romano Cherubino Leonardi 《Journal of plant nutrition》2014,37(9):1455-1474
The effects of nutrient or sodium chloride (NaCl) salinity on pepper grown in closed soilless culture systems were studied. A control (2 dS m?1) and two saline nutrient solutions (4 dS m?1) differing in the salt sources (fertilizers or NaCl) were studied. Shoot biomass production as well as total and marketable yield were more affected by NaCl than nutrient salinity. Fruit dry matter and total soluble solids increased in both salinity treatments compared to the control. Total phenol content rose slightly (10%) with NaCl salinity, while the concentration of carotenoids was enhanced by 40% with NaCl compared to the control and nutrient salinity. The results showed that the response of pepper to salinity is both osmotic and ion specific, but a more negative effect was recorded under NaCl stress. Moreover, the highest content of antioxidant compounds in NaCl treated fruits may indicate that NaCl caused more stressful conditions than nutrient salinity. 相似文献
76.
77.
Lee?P?llumaaEmail author Anne?Kahru Levonas?Manusadzianas 《Journal of Soils and Sediments》2004,4(4):267-275
Background and Objectives The current environmental legislation regulating pollution issues is based on total levels of pollutants. This approach is
not taking into account the bioavailability of pollutants (that is especially important for an analysis of soils and sediments
as heavy metals and hydrophobic organic toxicants tend to sorb to solid matrix) and effects of toxicants in mixtures. Thus,
toxicity-based criteria should be added to the currently existing chemical ones for the meaningful evaluation of the environmental
hazard. The aim of the current study was 1) to compare the ecotoxicity and chemistry-based environmental evaluations for 27
solid-phase environmental samples (soils, sediments, solid wastes); 2) to suggest the battery of biotests for the screening
of water-extracted toxicity.
Methods 14 soils, 9 sediments and 4 oil-shale industry solid waste samples from Estonia and Lithuania were analyzed for the concentration
of total PAHs, heavy metals, oil products and water-extracted phenols. The pollution level was evaluated by comparison of
measured concentrations with Estonian permitted limit values in residential (PLVr) and industrial (PLVi) areas for each key pollutant
A battery of 8 aquatic toxicity tests was applied for the analysis of aqueous extracts (L/S=3) of samples: tests with microalgaeSelenastrum capricornutum, macroalgaeNitellopsis obtusa, protozoaTetrahymena thermophila, crustaceansDaphnia magna andThamnocephalus platyurus, rotifersBrachionus calyciflorus and photobacteriaVibrio fiscberi. Particle-bound bioavailable toxicity was evaluated using a kinetic photobacterial assay withVibrio fiscberi (Solid-Phase Flash-Assay). The toxicity data were evaluated by MaxTox index (highest toxic signal of the battery).
Results Chemical evaluation and toxicological evaluation pointed to the same direction in half of the cases (13/27): 5 samples (including
2 presumably clean control soils) proved harmless and 8 hazardous to environment in case of both evaluations. However, there
was a disagreement between chemical and toxicological evaluations for the rest of the samples (14/27). In two mismatching
cases (soils from the territory of former gasoline stations) the level of oil products exceeded the PLVr, but no toxicity was detected, most probably due to the low bioavailability of aged pollutants. It must be taken as a warning
that a majority of mismatching cases (12/14) of the samples proved to be toxic or even very toxic despite the fact that the
measured hazardous key pollutant levels were below the PLVr. Within these 12 samples were 2 soils from municipal dumping sites, 2 soils from the territory of military airport, 6 sediments
from Curonian lagoon (Lithuania) and 2 oil-shale industry solid wastes (Estonia).
Conclusions The results of this study show the necessity of biotesting in environmental risk assessment to avoid the falsenegative results
that may result in harmful effects for the ecosystems and also to human health. The following, reduced test battery was proposed
for the ecotoxicological hazard assessment of water-extractable toxicity of solid-phase samples:Tetrahymena thermophila growth inhibition assay,Daphnia magna mortality assay andSelenastrum capricornutum growth inhibition assay. Also, the Microtox test (Vibrio fiscberi luminescence inhibition assay) could be valuable for screening purposes. For the evaluation of particle-bound, bioavailable
toxicity of soil suspensions, Solid-Phase Flash-Assay (test organismVibrio fiscberi) is suggested. Compared to the results obtained with the initial battery of 8 tests, the reduced battery detected the toxicity
in 85% of the cases. 相似文献
78.
不同菌株发酵枸杞汁中生物活性物质与香气组成物质含量变化 总被引:1,自引:0,他引:1
为研究枸杞汁经过不同菌株发酵后品质与挥发性成分的变化,采用酵素食品中分离的4株菌分别发酵枸杞汁,比较不同发酵枸杞汁的黄酮、蛋白质、总酚和挥发性成分等产品特性。结果表明:各菌种发酵液中黄酮含量均有显著增加;蛋白质和总酚含量差异显著,罗伊氏乳杆菌(Lactobacillus reuteri)发酵液蛋白质含量最高,为(599.50±1.53)μg·mL-1,巴达维亚芽孢杆菌(Bacillus bataviensis)发酵液含量最低,为(168.11±1.00)μg·mL-1;总酚含量最高的是巴达维亚芽孢杆菌(Bacillus bataviensis)发酵液,为鼠李糖乳杆菌(Lactobacillus rhamnosus)、地衣芽孢杆菌(Bacillus licheniformis)、罗伊氏乳杆菌(Lactobacillus reuteri)发酵液总酚含量的1.10~3.01倍。各菌种发酵液共检测到挥发性成分52个,其中共有成分24个,但含量在各菌种发酵液中存在显著差异,酸类物质对发酵后的枸杞汁风味影响较大。综合各个指标,4种菌株中的Bacillus... 相似文献
79.
酚类物质对核桃嫁接成活的影响 总被引:14,自引:0,他引:14
以富士苹果为对照,通过对嫁接成活率有显著差别的上宋6号、元丰和薄壳香三个核桃品种接穗中营养物质和酚类物质(包括酚类物质总量、酚酸类物质和核桃醌)的定量分析测定表明,酚类物质总量不是核桃嫁接成活困难的主要原因。其中,某些对愈合起抑制作用的酚类物质的存在,或对愈合起促进作用的酚类物质的缺少,可能是影响核桃嫁接成活的主要原因。 相似文献
80.
[目的]测定核桃青皮80%乙醇提取物及其经大孔树脂HP-20分段后的各纯化部分的总酚含量,评价其各部分的抗氧化能力,并分析总酚含量与抗氧化能力的关系。[方法]采用福林-酚比色法,测定总酚含量,通过DPPH·和ABTS·自由基清除法评价其抗氧化能力。[结果]核桃青皮提取物及其各纯化部分均表现出一定的抗氧化性,其中Fr.2(20%甲醇洗脱部分)、Fr.3(40%甲醇洗脱部分)部分的IC50(半数抑制浓度)均高于VC(抗坏血酸),Fr.4(60%甲醇洗脱部分)和Ext.(80%乙醇提物部分)与VC相当,并且总酚含量和抗氧化能力呈正相关。[结论]经过大孔树脂HP-20处理后的核桃青皮乙醇提取物,其总酚的含量得到了富集,为进一步研究核桃青皮各部分的物质成分提供了依据。同时表明核桃青皮的提取物可以作为天然的抗氧化剂应用于食品、医疗、化妆品、保健品等行业。 相似文献