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1.
内蒙古草原羊尿斑块土壤氮素的变化特征 总被引：2，自引：0，他引：2
在内蒙古草原对天然羊尿尿斑土壤氮素的变化进行了系统研究，结果表嘎：随着羊尿的施入，土壤NH4^＋-N浓度显著升高（P〈0．01），并于第3天达到最大值；施后7d前（不包括第7天），与对照区相比，施尿区土壤NO3^--N浓度显著降低（P〈0．05），7d后，施尿区土壤NO3^-N浓度显著高于对照区（P〈0．01）；羊尿施入35d前（不包括第35天），土壤NH4^＋N浓度显著高于N03^--N（p〈0．05），而35d后，NH4^＋-N浓度开始低于N03^-N，而且差异显著（p〈0．05）.施尿后，土壤微生物量氮呈增加趋势，并于第35d达到最大值，而后开始下降，84d后又出现升高现象；施尿区0—5cm和5-10cm土壤微生物量氮显著高于对照区（P〈0．05），但10—20cm土壤差异不显著（P〉0．05）。施尿后，土壤可溶性有机氮浓度显著升高（P〈0．05），并于第7天达到最大值，而后呈下降趋势，3个取样层次呈一致的变化趋势。施尿区和对照区土壤无机氮与可溶性有机氮、无机氮与微生物量氮存在显著的正相关关系（P〈0．05，P〈0．01），但土壤可溶性有机氮与微生物量氮相关不显著（P〉0．05）。 相似文献
2.
皖麦38添加木聚糖酶对鸡表观代谢能值和氨基酸表观消化率的影响 总被引：14，自引：0，他引：14
用32只小公鸡进行代谢试验，研究高戊聚糖含量小麦品种皖麦38添加木聚糖酶对鸡表观代谢能值（AME）和氨基酸表观消化率的影响。结果显示，木聚糖酶使鸡的表观代谢能值（干物质基础）提高4．14％（P＜0．05），干物质消化率提高5．98％（P＜0．05），有机物消化率提高5．36％（P＜0．05），粗脂肪消化率提高3．01％（P＞0．05）。氨基酸表观消化率分析表明，木聚糖酶对赖氨酸和天冬氨酸的消化率分别提高5．19％（P＞0．05）和5．00％（P＞0．05）；组氨酸和脯氨酸的消化率分别提高3．67％（P＜0．05）和2．39％（P＜0．05）；亮氨酸、精氨酸、缬氨酸、丙氨酸、胱氨酸的消化率分别提高2．12％－4．18％不等；对其它氨基酸的消化率没有明显影响。 相似文献
3.
Caffeoyl Glycoside对小鼠免疫细胞功能的影响 总被引：1，自引：0，他引：1
本实验室从胡黄连根茎分离到1,6-di-O-caffeoyl-β-D-glucopyranoside单体Caffeoyl Glycoside（CG）,体外试验测定其对小鼠免疫细胞功能的影响。通过MTT法检测CG对Balb／c小鼠脾淋巴细胞增殖,NK细胞对K562细胞杀伤活性的影响,以及小鼠腹腔巨噬细胞（PMφ）能量代谢水平;CG对PMφ吞噬中性红能力的影响。CG在一定剂量范围内单独或者协同非特异性丝裂原（ConA或LPS）作用均能够显著增强小鼠脾淋巴细胞、PMφ的增殖能力（P〈0．05或P〈0．01）,CG单独作用就能显著提高NK对K562细胞的杀伤活性（P〈0．05或P〈0．01）。CG在体外对小鼠主要免疫细胞的增值和功能方面具有显著的促进作用（P〈0．05或P〈0．01）。研究结果显示CG具有特异性与非特异性的免疫增强作用。 相似文献
4.
甘草甜素对金黄色葡萄球菌诱发小鼠实验性乳腺炎的影响 总被引：1，自引：0，他引：1
【目的】探讨甘草甜素对金葡菌所致小鼠乳腺炎控制效果；【方法】30只BALB/C雌孕鼠随机分成正常对照组（Con,n=10）、阳性对照组（P,n=10）和试验组（T,n=10）。阳性对照组和试验组母鼠于产后8-10d经乳头管注入50μl 7.0×102CFU细菌悬液，生理盐水组注入50μl 灭菌生理盐水。30只母鼠于接菌-12h、0h、12h、36h腹腔注射甘草甜素88mg/kg或生理盐水0.2ml。接菌后66h处死小鼠，取乳腺组织固定，进行组织学观察；【结果】观察显示P组的小鼠乳腺组织破坏得最为严重。P组小鼠乳腺组织间质宽度与正常对照组相比极显著增加（p＜0.01）,T组小鼠乳腺组织间质宽度极显著高于正常对照组（p＜0.01），与P组相比极显著减少（p＜0.01）；与正常对照组相比，P组小鼠乳腺组织中TNF-α、INF-γ含量极显著升高（p＜0.01），T组小鼠乳腺组织中TNF-α、INF-γ含量与P组相比极显著降低（p＜0.01）。【结论】结果表明，甘草甜素不仅减少乳腺内的细菌数，降低对组织的损伤，而且减轻乳腺炎症变化及全身反应，对乳腺具有一定的保护作用。 相似文献
5.
大气O3浓度升高对玉米光合作用和籽粒品质的影响 总被引：2，自引：0，他引：2
利用开顶式气室研究了大气O3浓度升高对玉米（Zea mays L．）叶片光合作用、籽粒品质以及产量的影响。结果表明,整个生长季内,与对照相比,在高浓度O3（80nmol／mol）条件下,玉米叶片的净光合速率、气孔导度、蒸腾速率显著下降（P〈0．05）,而胞间CO2浓度先降低后升高并达到极显著水平（P〈0．01）,这说明使光合速率降低的主要因素由气孔限制逐渐转变为非气孔限制。与对照相比,高浓度O3处理植株叶绿素a、叶绿素b及叶绿素（a＋b）含量降低,叶绿素a／b值则先降低后升高。但是随着熏蒸时间的延长,高浓度O3处理植株的叶绿素a、叶绿素（a＋b）含量与叶绿素a／b值变化呈先升高后降低的趋势,与叶绿素b含量变化不同;O3浓度升高在一定程度上使玉米籽粒品质下降,其中蛋白质和淀粉含量降低,而粗脂肪和蛋脂总量略有升高;百粒重、穗粒数和穗粒重均显著低于对照（P〈0．05）,说明O3浓度升高降低了玉米的光合能力,籽粒品质受到影响,抑制了作物生长。 相似文献
6.
为研究日粮中不同比例小麦替代玉米对奶牛氮代谢参数的影响,选择8头泌乳天数为84±17 d,体重为569±47 kg的经产中国荷斯坦奶牛作为试验动物,采用重复4×4拉丁方设计,分别饲喂含不同比例粉碎小麦（ GW）和粉碎玉米（GC）的日粮,4个处理组分别为（DM基础）：W0组（0％GW＋27．9％GC）,W9．6组（9．6％GW＋19．2％GC）,W19．2组（19．2％GW＋9．6％GC）和W28．8组（28．8％GW＋0％GC）。结果表明：奶牛的产奶量、乳蛋白率和乳蛋白产量未受影响;随着日粮中小麦比例的增加,奶牛的干物质采食量（DMI）呈二次曲线增加趋势（P＝0．07）,牛奶尿素氮（MUN）浓度线性增加（P＜0．01）,且W28．8组显著高于W0和W19．2组（P＜0．01）;粪氮排出量未受日粮影响,尿氮排出量呈线性增加趋势（P＝0．08）;尿氮（P＝0．02）和总排出氮（粪氮＋尿氮）（P＝0．05）占食入氮的比例呈二次曲线降低;尿素氮产量（P＜0．01）及其占总尿氮的比例（P＝0．03）线性增加,且W19．2和W28．8组的尿素氮产量显著高于（P＝0．01）其他2组;尿中尿囊素（P＝0．05）和总嘌呤（P＝0．09）产量呈线性降低趋势,W9．6组的微生物氮产量显著（P＝0．02）高于W28．8组。结果提示：泌乳盛期奶牛日粮中用9．6％的粉碎小麦替代玉米效果最佳,高比例的小麦替代玉米（ W28．8组）时能够增加尿氮及奶和尿中尿素氮的排出量,降低微生物氮的合成。 相似文献
7.
为了研究家兔ATG16 L1基因对非特异性消化道紊乱的易感性,试验采用PCR-HRM 技术,首次对家兔ATG16L1基因进行单核苷酸多态性（ SNP）检测,同时结合低纤维群体结肠ATG16L1基因 mRNA表达量进行关联分析。结果表明：ATG16L1基因存在1个SNP位点（ c．1482 G＞A）与NSDD的易感性相关联;c．1482 G＞A位点A等位基因能增加NSDD的易感性（OR ＝1．43,95％置信区间：1．08～1．91,P ＜0．05）;在隐性遗传模型中,AA基因型能增加NSDD的易感性（OR ＝1．69,95％置信区间：1．05～2．78,P ＜0．05）;ATG16L1基因在结肠中的mRNA表达量随着炎症的加剧显著升高（P ＜0．05）;AA基因型在整个低纤维诱导NSDD组中的表达水平最低（P ＜0．05）。这些结果均表明,ATG16L1基因与家兔NSDD的遗传易感性相关。 相似文献
8.
生长调节剂2,4-D灌施对烤烟上部叶常规化学成分的影响 总被引：1，自引：3，他引：1
以代表性烤烟品种云烟87为材料，用不同浓度的2，4-D水溶液对打顶后的烟株进行了灌施处理，采用连续流动分析法及火焰光度法测定上部叶初烤烟的常规化学成分含量。结论是：（1）0—100mL／L2，4-D灌施，浓度与烤烟上部叶烟碱含量呈极显著的负相关（P〈0．01），与上部叶的糖碱比值呈极显著的正相关（P〈0．01），与其钾含量呈显著的正相关（P〈0．05）；（2）2，4-D灌施可以显著降低烤烟上部叶的烟碱含量、提高上部叶糖碱比值及钾含量；（3）2，4-D灌施对烤烟上部叶的还原糖及氯含量均无明显影响；（4）2，4-D灌施可提高烤烟上部叶常规化学成分的协调性，从而提高上部叶的可用性。 相似文献
9.
外源硒对镉胁迫下芥菜种子萌发生理效应的影响 总被引：2，自引：0，他引：2
采用水培的方法,以芥菜为材料,研究了施加不同质量浓度外源硒（Se）（1,2,6,8 mg/L）对单一质量浓度镉（Cd）（10 mg/L）胁迫下芥菜种子萌发生理效应的影响。结果表明,单一质量浓度Cd胁迫显著抑制了芥菜种子的发芽（P＜0．01）,种子萌发过程中幼苗中的可溶性糖含量和淀粉含量显著低于对照（P＜0．01）,丙二醛（MDA）含量则明显高于对照（ P＜0．01）,表明单一Cd对芥菜种子的萌发产生了一定程度的伤害;单一Cd胁迫下加入不同质量浓度外源Se后,能够有效地提高种子的发芽率,使可溶性糖和淀粉含量增加,MDA含量明显降低,表明外源Se可以有效地缓解Cd对芥菜种子萌发造成的伤害;当外源Se质量浓度为2 mg/L时,芥菜的发芽率、可溶性糖含量和淀粉含量为最大值,且与对照相比变化不大（P＞0．05）,但均显著高于单一Cd胁迫下的相应值（P＜0．01）,MDA含量最低,且显著低于对照和单一Cd胁迫下的相应值（P＜0．01）,表明当外源Se的质量浓度为2 mg/L时,对单一质量浓度Cd胁迫下芥菜种子萌发的缓解作用最佳。 相似文献
10.
β-谷甾醇对脂多糖诱导的小鼠急性肺损伤的保护作用研究 总被引：1，自引：0，他引：1
为了探究β-谷甾醇对LPS诱导的急性肺损伤小鼠的保护作用及其可能的机制,利用酶联免疫吸附法(ELISA)测定β-谷甾醇对RAW 264.7细胞产生肿瘤坏死因子(TNF-α)和白细胞介素-6(IL-6)的影响。给BALB/c小鼠鼻腔滴注LPS(0.5mg/kg)构建小鼠急性肺损伤模型,滴鼻24 h后检测各指标。ELISA检测小鼠肺泡灌洗液中(BALF)的炎性细胞因子含量;称重法检测肺组织湿/干重比和肺含水量;HE染色法观察肺组织病理形态学变化;应用蛋白印迹法(western blot)检测小鼠肺脏中核转录因子-κB (NF-κB)信号转导通路中相关蛋白的含量变化。结果表明,β-谷甾醇能剂量依赖性降低RAW 264.7细胞上清及ALI小鼠BALF中TNF-α和IL-6的表达水平。肺脏称重结果和病理形态学结果显示β-谷甾醇可明显减轻LPS诱导的肺水肿和炎症反应。另外,western blot结果表明β-谷甾醇不仅能够下调NF-κB p65 的活化,还抑制了NF-κB阻断剂IκBα的磷酸化。β-谷甾醇对LPS所致的小鼠急性肺损伤有较好的保护作用,其保护机制可能与阻止炎症因子(TNF-α、IL-6)的释放和下调NF-κB信号转导通路的活化有关。 相似文献
11.
Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献
12.
C. J. Spurr D. A. Fulton P. H. Brown R. J. Clark 《Journal of Agronomy and Crop Science》2002,188(4):275-280
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality. 相似文献
13.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
14.
G. H. Kroon 《Euphytica》1994,76(1-2):125-125
Summary
K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes. 相似文献
15.
Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
16.
Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed. 相似文献
17.
Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes. 相似文献
18.
W. Erskine M. Tufail A. Russell M. C. Tyagi M. M. Rahman M. C. Saxena 《Euphytica》1993,73(1-2):127-135
Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed. 相似文献
19.
Herbage yield trials are necessary to test if candidate varieties are well suited for organic conditions. In order to elucidate
a particular suitability for organic conditions, we run such trials in parallel under both organic and conventional conditions.
Here, we report on second and third year results of the sowings 2004 and 2005. These trials are part of a targeted breeding
programme for organic conditions. Irregular colonisation of pure grass plots with adventitious plants, in particular white
clover, was recognized as a major constraint to the quality of the results obtained under organic conditions. The coefficients
of variance in dry matter yield almost doubled when compared to conventional trials, and significant differences in annual
yield among varieties were rare. However, when herbage yield was corrected for the estimated fraction of adventitious plant
colonization at each cut, the number of instances with statistically significant differences for annual yield among varieties
increased more than fourfold. Dry matter yields under organic and conventional conditions were significantly and positively
correlated. However, analysis of variance showed a significant culture type by variety interaction for annual dry matter yield
in 12 out of 24 trials. When diploid and tetraploid varieties of the same Lolium species were tested in one common trial, only tetraploid varieties were identified as being particularly well suited for organic
conditions, while in these trials, the great majority of apparently poorly suited varieties were diploid. This suggests that
breeding tetraploid Lolium varieties is promising when aiming at a favourable response to organic agriculture. 相似文献
20.
Summary Six pear and five apple trials were carried out to ascertain the outcome of combinations of compatible pollen (C) with self (S) or incongruous pollen (I) as to the pollination index (PI=seeds/pollinated flower). The PI of the mixture C+I (1:5) was consistently depressed as compared to that of the control C. The results of the double pollinations S/C and I/C were affected by the temperature at pollination; their PI's at <15°C were twice as high as those at >15°C, being well above and below the PI of C in the former and latter case respectively. The opposite was true for the C/S combination, the PI of which increased with the pollination temperature; the PI of C/I did not differ much from the PI of C, irrespective of temperature. The conclusion was reached that the interaction previously and presently found between compatible and self-incompatible pollen also exists to a fair extent between compatible and incongruous pollen. However, in pear neither the mentor nor the pioneer pollen technique proved to aid its hybridization with apple, the formation of self seed was not observed either. In apple the production of apple × pear hybrids was likewise doubtful, but the double pollinations S/C and C/S formed 4–10% self seed. 相似文献