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1.
本文对不同施肥措施下麦田土壤微生物数量及种类的变化进行了测定和分析。结果表明 :有机肥与N、P、K肥的合理配施 ,肥效持久 ,能促进微生物生长繁殖 ,细菌、放线菌、真菌、固氮菌、纤维素分解菌数量均能相对长期保持较高水平 ;可显著增强纤维素分解强度 ,促进土壤有机质的分解 ,有利于培肥土壤。微生物种类鉴定表明 :细菌的数量以芽孢杆菌为主 ,球菌较少 ;放线菌主要为链霉菌属的灰褐色类群 ;真菌主要为腐霉属、木霉属、葡萄孢属 ;固氮菌为圆褐固氮菌 ;纤维素分解菌以食纤维细菌、链霉菌属的白孢类群和葡萄穗霉属、腐霉属等真菌最常见 相似文献
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不同施肥处理对西藏山南地区麦田土壤微生物变化的影响 总被引：4，自引：0，他引：4
本文对不同施肥措施下麦田土壤微生物数量及种类的变化进行了测定和分析。结果表明：有机肥与N、P、K肥的合理配施，肥效持久，能促进微生物生长繁殖，细菌、放线菌、真菌、固氮菌、纤维素分解菌数量均能相对长期保持较高水平；可显著增强纤维素分解强度，促进土壤有机质的分解，有利于培肥土壤。微生物种类鉴定表明：细菌的数量以芽孢杆菌为主，球菌较少；放线菌主要为链霉菌属的灰褐色类群；真菌主要为腐霉属、木霉属、葡萄孢属；固氮菌为圆褐固氮菌；纤维素分解菌以食纤维细菌、链霉菌属的白孢类群和葡萄穗霉属、腐霉属等真菌最常见。 相似文献
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报道枝孢属一新记录种:马缨丹枝孢C lad osporium lantanae。其形态特点是:分生孢子梗直立,稍弯曲,淡褐色;枝孢顶具2~3个孢痕,淡褐色,无隔膜。分生孢子顶生或侧生,形成短孢子链,椭圆形,0~1个隔膜,大多数无隔膜,基部有孢痕,淡褐色,平滑。另报道6种枝孢的8种国内新寄主植物、2个已知种的地理新分布和4个已知种。研究标本存云南农业大学真菌标本室(MHYAU)。 相似文献
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拟盘多毛孢菌属真菌侵染的寄主种类多、范围广,可引起多种经济作物和观赏植物的多类病害,病征具有多样性。在前期对贵州省油茶叶枯病的研究过程中,分离到一个拟盘多毛孢菌的新致病菌KLXY-7-2。通过病原菌的分离与纯化、形态学鉴定和微管蛋白基因(TUB2)构建系统发育树等多种检测方法,KLXY-7-2菌鉴定结果为木防已拟盘多毛孢菌(Pestalotiopsis cocculi)。病原菌与拟盘多毛孢属EF055226.1、EF055231.1真菌聚为一个独立的进化分支,且置信度为99%。本研究所鉴定的油茶木防已拟盘多毛孢菌(Pestalotiopsis cocculi),在油茶叶枯病的相关研究属于首次报道,可为进一步明确该病原菌的发生规律及预防时期提供科学依据。 相似文献
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《土壤通报》2010,(6)
试验分离鉴定了嫁接茄子的根际真菌,并采用对峙培养法,研究了这些根际真菌对茄子黄萎病菌的作用效果。结果显示,嫁接处理根际真菌的优势种主要是烟曲霉原变种(Aspergillus fumigatus var.fumigatus)、赭曲霉(Aspergillus ochraceus)、腐皮镰孢(Fusarium solani)和土曲霉(Aspergillus terreus);CK则主要是土曲霉(A.terreus)、露湿漆斑菌(Myrothecium roridum)和腐皮镰孢(F.solani)。在所分离的13属17种根际真菌中,烟曲霉原变种(A.fumigatus var.fumigatus)、粘轴霉属(Gliocladium sp.)和瓶霉属(Phialophora sp.)真菌对黄萎菌的拮抗作用最强。此外,黄暗青霉菌(Penicillium citreonigrum)、土曲霉(A.terreus)、枝顶孢属(Acremonium sp.)、链格孢(Alternaria alternata)和弯孢属(Curvulariasp.)真菌对黄萎菌也表现出了较强的抑制作用。各嫁接处理根际真菌的优势种均包括对黄萎病菌有高拮抗作用的烟曲霉原变种,这可能与嫁接茄比自根茄抗病性强有关。 相似文献
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被孢霉对土壤养分有效性和秸秆降解的影响 总被引：1，自引：0，他引：1
腐生真菌被孢霉在富含有机质的土壤中丰度很高,为土壤碳及养分转化的关键微生物成员。然而目前关于土著被孢霉在秸秆分解过程中对土壤养分有效性影响的研究较少。采用常规平板稀释法从长期施用有机肥的红壤和砂姜黑土中分离真菌菌株,将分离得到的菌株序列与基因库（GenBank）中的序列进行比较,鉴定出了两株被孢霉菌株,即高山被孢霉（Mortierella alpina）和长孢被孢霉（Mortierella elongata）。通过设置盆栽试验,每盆土接种10 g菌剂,研究两株被孢霉对秸秆降解过程中土壤养分有效性和细菌群落的影响。结果表明,在红壤中,与未接种对照相比,接种高山被孢霉处理的土壤有效磷含量提高了29.0%,长孢被孢霉处理下土壤有效氮含量和β-葡萄糖苷酶活性分别提高了15.5%和81.3%。在砂姜黑土中,与对照相比,被孢霉菌株显著提高了土壤可溶性有机碳,速效氮和有效磷的含量以及β-葡萄糖苷酶和磷酸酶的活性。两株被孢霉在红壤中抑制了秸秆的降解,并显著改变细菌群落组成。而在砂姜黑土中,被孢霉菌株促进了秸秆降解,且对细菌群落结构影响不大。在红壤中,苍白杆菌属（Ochrobactrum）、无色杆菌属（... 相似文献
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从北京市房山区百合资源圃采集红芯百合(Fangio)植株样品,通过组织块分离法分离内生细菌;进一步以百合灰霉病菌—灰葡萄孢菌( Botrytis cinerea)ACCC36423、百合叶尖干枯病菌—葡萄座腔菌( Botryosphaeria dothidea)ACCC37263和百合枯萎病菌—尖孢镰刀菌( Fusarium oxysporum)F01139等几种主要百合病原真菌为指示菌,采用平板对峙法筛选具有拮抗活性的拮抗菌株;并对拮抗菌株进行产 1-氨基环丙烷 -1-羧酸(ACC)脱氨酶活性、产生长素(IAA)、溶磷、产铁载体等多种植物促生特性测定;最后通过形态观察及 16S rRNA基因序列分析,初步鉴定其种属。结果从百合茎部分离获得一株内生细菌菌株 FJb-2;该菌株对灰葡萄孢菌、葡萄座腔菌和尖孢镰刀菌均有较高拮抗活性,对病原真菌生长的抑制率范围为 60%～ 81%;该菌株产 ACC脱氨酶活性为 相似文献
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为了研究刺萼龙葵入侵的微生物学机制,分别在2008年至2009年7月、8月在刺萼龙葵入侵严重的朝阳地区选择3个样区,即入侵区(Ⅰ)、耕作区(Ⅱ)及土著区(Ⅲ)进行选择性取土及抽样调查,对采集的75份土样经分离、纯化、鉴定的真菌分属30个属,通过对刺萼龙葵入侵区(Ⅰ)土壤真菌的培养,共分离鉴定出了约40种真菌,且分属21个属;其中在刺萼龙葵入侵区(Ⅰ)土壤真菌的各种类群中,以青霉属(Penicillium)、曲霉属(Aspergillus)、毛霉属(Mucor)、根霉属(Rhizopus)、木霉属(Trichoderma)、镰孢菌属(Fusarium)、枝顶孢属(Acremonium)种类较多,为优势类群,其分离频率分别为18.13%、15.20%、8.77%、8.77%、7.60%、5.85%、5.26%。而附球菌属(Epicoccum)、接霉属(Zygorhynchus)、节丛孢属(Arthrobotrys)、弯孢属(Cunularia)菌株数仅为1,为该区稀有类群;通过对入侵区(Ⅰ)、耕作区(Ⅱ)及土著区(Ⅲ)土壤真菌数量比较发现,入侵区(Ⅰ)土壤真菌数量是耕作区(Ⅱ)的1.6倍,而入侵区(Ⅰ)与土著区(Ⅲ)的土壤真菌数量相差不大,比例接近1;根据Jaccard相似性指数原理,入侵区(Ⅰ)、耕作区(Ⅱ)和土著区(Ⅲ)的土壤真菌群落相似性处在中等相似的水平,其土壤真菌群落相似性差异性并不显著。结果表明刺萼龙葵入侵并没有使土壤可培养真菌多样性产生明显的变化。 相似文献
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从分子系统学角度分析拟盘多毛孢属及其近缘属的界限 总被引：1，自引：1，他引：1
拟盘多毛孢属和截盘多毛孢属的划分界限长期以来因分类学家的观点不一致而处于模糊状态，以核糖体DNA的内转录间区序列建立分子系统树的结果支持五细胞分生孢子类型应归入拟盘多毛孢属，四细胞分生孢子类型应归入截盘多毛孢属，分子系统树同时可以反映无性阶段和有性阶段之间的联系，显示出分子系统学对形态分类学的客观性的评判作用。 相似文献
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Leila Shekari Maryam Mozafariyan Mirza Hasanuzzaman Farshad Sadeghi 《Journal of plant nutrition》2017,40(6):761-772
Selenium (Se) is an essential element for humans but is not considered as essential for plants. However, its beneficial role in improving plant growth and stress tolerances is well established. In order to study the role of Se in cadmium (Cd) toxicity in pepper (Capsicum frutescens cv. Suryankhi Cluster), this experiment was carried out in greenhouse conditions. Treatments comprised Cd [0, 0.25, and 0.5 mM cadmium chloride (CdCl2)] and Se [0, 3, and 7 µM sodium selenite (Na2SeO3)] with three replications. The result showed that Cd decreased chlorophyll a, chlorophyll b, and carotenoids, whereas Se supplementation diminished Cd toxicity on photosynthetic pigment. Selenium at 7 µM significantly increased the leaf area in the plants grown at 0.25 mM Cd. The application of Se at 3 µM with 0.25 mM Cd and Se at 3 µM and Se at 7 µM with 0.5 mM Cd increased the activity of catalase (CAT). Selenium at 7 µM decreased the proline content of pepper leaves exposed to Cd at 0.5 mM (30%). Selenium significantly enhanced the antioxidant activity of leaves, which was diminished by Cd toxicity. In general, Se has a beneficial effect on plant growth and is an antioxidant enzyme of pepper cv. Suryankhi Cluster under Cd stress and non-stress conditions. 相似文献
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M. Kaplan 《Journal of plant nutrition》2013,36(2):237-244
Copper (Cu)‐containing fertilizers, fungicides, and bactericides has been used extensively in the greenhouses in the Antalya province in recent decades with the use of such materials tending to increase year by year. The level of DTPA‐extractable Cu was determined in 210 soils (0–20 and 20–40 cm depth) and 105 leaf samples obtained from 105 tomato greenhouses. The DTPA‐extractable Cu contents of the soils taken from the 0–20 depth ranged between 0.76 and 88.03 mg kg‐1 (mean 7.79 mg kg‐1). The percentage of soils containing DTPA‐extractable Cu greater than the critical toxicity level (20 mg kg‐1) was 8.1. The Cu content of tomato leaf samples ranged between 2.4 and 1,490 mg kg‐1 (mean 166.5 mg kg‐1). The Cu concentration in leaf samples was very high due to the intensive use of foliar applied Cu‐containing chemicals. As a consequence, 24.8% of the leaf tomato samples analyzed contained over 200 mg Cu kg‐1, the maximum accepted tolerance level. Therefore, it may be necessary to reduce the use of Cu‐containing pesticides and fertilizers, or at least reduce the amount of Cu‐containing fertilizers being used in those greenhouses where Cu‐containing pesticides have been or are being used. 相似文献
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红壤区不同肥力水稻土根际硝化作用特征 总被引：3，自引：1，他引：2
通过根际培养箱(三室)——速冻切片技术研究了红壤地区高、低两种肥力下水稻苗期根表、根际和土体土壤矿质态氮含量和硝化强度,以及水稻生长、氮素积累的差异。结果表明,肥力水平对水稻根表和根际土壤铵态氮(NH4+-N)含量无显著影响,但高肥力显著提高土体土壤NH4+-N含量,以及根表、根际和土体土壤硝态氮(NO3--N)含量及硝化强度。两种肥力水稻土硝化强度最大值均出现在距根表2 mm处,分别为0.20和0.31μmol kg-1 h-1。土体土壤硝化强度随距根表距离增加而降低,低肥力土壤在距根表10～40mm处时硝化强度接近本底值,而高肥力土壤在距根表20～40 mm处时接近本底值。与不种水稻的CK相比,种植水稻显著提高根际土壤硝化强度。高肥力能显著改善水稻生长,增加植株氮素积累量,尤其显著促进根系生长及通气组织发育。由于红壤稻田肥力水平的差异造成水稻根际硝化强度以及水稻吸收NO3-的差异,导致高肥条件下水稻显示出更强的生长势和氮素吸收利用能力。因此,合理提高红壤稻田肥力水平对改善红壤区水稻根际土壤硝化作用及水稻氮素营养具有重要意义。 相似文献
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Sandro Froehner Karina Scurupa Machado Elisa Stefen Marcelo Nolasco 《Water, air, and soil pollution》2011,219(1-4):591-599
The presence of sexual hormones (female estrogens) was assessed in sediments of a mangrove located in the urban region of southern Brazil. The estrogens are involved in human sexual reproduction. They act as the chemical messengers, and they are classified as natural and synthetic. The estrogens inputs in the environment are from treated and untreated sewage. The presence of estrogens in sewage is excretion from the female due to natural production and use of contraceptives (synthetic estrogens). With the indiscriminate release of sewage into the environment, estrogens can be found in rivers, lakes, and even in oceans. In this work, the presence of estrone (E1), 17-??-estradiol (E2), and 17-??-ethynilestradiol (EE2) in eight sedimentary stations in Itacorubi mangrove located on Santa Catarina Island, south Brazil, was investigated. Historically, the Itacorubi mangrove has been impacted by anthropogenic activities because the mangrove is inserted in the urban area of the Florianopolis. The estrogen EE2, used as contraceptive, had the highest concentration in mangrove sediment, 129.75?±?3.89 ng/g. E2 was also found, with its concentration ranging from 0.90?±?0.03 to 39.77?±?1.19 ng/g. Following the mechanism, under aerobic or anaerobic conditions, E2 will first be oxidized to E1, which is further oxidized to unknown metabolites and finally to CO2 and water (mineralized). EE2 is oxidized to unknown metabolites and also finally mineralized. Theoretically, under anaerobic conditions, EE2 can be reduced to E1 even in environments such as mangrove which is essentially anaerobic. 相似文献
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自由基在鸡肾病发生中的作用研究 总被引：2，自引：2，他引：0
肾病即急性肾小管坏死.鸡肾病在养鸡生产中极为常见,尤其近年来,鸡肾病的发生日益增多,由于其发生机制不清楚,临床治疗鸡肾病的依据不足,致使治疗效果不佳,为此,提出本研究以探讨鸡肾病的发生机制,为本病防治提供理论依据. 相似文献
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Ohnishi H Iwanaga S Kawazoe K Ishizawa K Orino S Tomita S Tsuchiya K Kanematsu Y Harada N Mori K Tsuchihashi T Ishikawa Y Tamaki T 《Journal of agricultural and food chemistry》2008,56(21):10092-10098
This study investigated whether reducing agents such as quercetin and iron(II) facilitate formation of nitric oxide (NO) gas from orally ingested nitrite in an vivo study. When 3 mg/kg Na (15)NO2 was orally administered to rats with or without iron(II) or quercetin, Hb (15)NO, which is indicative of systemic (15)NO, was detected in the blood, with the maximum blood concentration of Hb (15)NO at 15 min after nitrite or nitrite plus quercetin treatment, whereas after administration of nitrite plus iron(II) or nitrite plus iron(II) and quercetin, the time was shortened to 10 min. Interestingly, iron(II), quercetin, or iron(II) plus quercetin did not affect the total amount of Hb (15)NO generated from orally administered Na (15)NO2. However, the systemic nitrite concentration was significantly decreased in the presence of iron(II) or iron(II) plus quercetin. These results may indicate that iron(II) is critical to the generation of NO gas from nitrite, whereas quercetin contributed little under the in vivo experimental conditions. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(15):1948-1959
Brazil is the largest producer of oranges (Citrus sinensis) in the world. The nutrient management of tree orchards is designed from experiments with a limited number of varieties. This knowledge is transferred to other varieties by diagnosing tissue nutrient composition and tree demand. Compositional data analysis has been first applied to tissue analysis of agricultural crops using centered log ratios with compositional nutrient diagnosis (CND-clr). The isometric log ratio (ilr) transformation is a new approach based on binary nutrient ratios and the principle of orthogonality (CND-ilr). We analyzed eleven nutrients: nitrogen (N), sulfur (S), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) in leaf tissue samples across 108 commercial plots (thirty-one grow Valencia, twenty-two Hamlim, twenty Pera, and thirty-five Natal). Nutrients were partitioned between macro- and micronutrients as well as anionic and cationic species. The effect size of varieties over Valencia was quantified by the mean and standard deviation of ilr values across ilr coordinates. Specific varietal nutrient profiles and ilr norms were defined. The nutrient profile of orange varieties could be classified into homogeneous groups to take advantage of fertilizer trials conducted on varieties of the same group. The Aitchison distance and a perturbation vector could be instrumental for diagnostic purposes and nutrient management. 相似文献
19.
Role of aldehyde oxidase in the hepatic in vitro metabolism of 3-methylindole in pigs 总被引：2，自引：0，他引：2
The metabolism of 3-hydroxy-3-methylindolenine (HMI), a recently discovered metabolite of 3-methylindole (3MI, skatole) produced by porcine liver microsomes, was investigated in vitro using porcine liver cytosol. HMI was rapidly metabolized to a single product, 3-hydroxy-3-methyloxindole (HMOI), by porcine cytosol. By the use of the selective inhibitors menadione and quinacrine, it was shown that the enzyme responsible for the oxidation of HMI into HMOI was aldehyde oxidase (AO; aldehyde:oxygen oxidoreductase, EC 1.2.3.1). The activity of AO in the conversion of HMI to HMOI was measured in a population of pigs (n = 30) with a wide range of 3MI levels in back fat (0.07-0.30 mg/kg). AO activity was found to be negatively correlated (r = -0.70; P < 0.001) with the level of 3MI in fat. The results of the present study suggest that AO plays an important role in the metabolism of 3MI in the pig and that its catalytic activity is related to an adequate 3MI clearance. 相似文献
20.
响应面设计法在温室番茄栽培中的应用 总被引：3，自引：2，他引：1
为优化温室番茄的栽培条件,试验研究了不同栽培密度、施氮量和施钾量对日光温室番茄产量的影响。通过中心复合试验设计,构建三因素（栽培密度,氮肥,钾肥）五水平的响应面设计方法并建立番茄产量与三因子的二次回归数学模型。结果表明:三因素对温室番茄产量均有显著的影响（p0.01）,影响的大小顺序为栽培密度施钾量施氮量;栽培密度与施氮量、施钾量之间存在显著的交互作用（p0.01）,施氮量与施钾量之间的相互作用对番茄产量影响不显著（p0.05）;多元二次回归分析结果显示,栽培密度、施氮量、施钾量与番茄产量之间的回归模型高度显著（p0.01）。统计分析确定温室番茄的最佳栽培条件为:栽培密度4.83万株/hm2,施氮量262 kg/hm2,施钾量513kg/hm2;在此条件下,温室番茄产量的预测值为119381kg/hm2,验证试验所得产量为121005kg/hm2。本研究为日光温室番茄高产、稳产和优质提供了理论依据。 相似文献