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131.
为了解特定生态环境中晚稻稻种的非致病细菌多样性以更有效地治理水稻主要病害,于1996-2001年间对采自浙江平原、丘陵及山区的606份稻种样本进行了非致病细菌种类、频率及对水稻纹枯病和恶苗病的抑菌作用研究。从中分离出9605个菌株,经致病性测定、菌落形态及部分细菌学特征(革兰氏染色、KMB培养基上的荧光色素和扩散性非荧光色素、YDC培养基上黄色菌落的产生、好气性、鞭毛及芽孢的染色镜检等)测定后,选出代表菌株622个,连同80个对照菌株用Biolog及脂肪酸分析法(FAME)进行测试。鉴定出Pseudomonas属11个种或型及其他14属的23种非致病细菌,并发现Pseudomonas属中55%的种及其他属中49%的种存在对水稻纹枯病或恶苗病的拮抗菌株,但不同种间的抑菌率存在较大差异。3类稻区均以Bacillus spp.、Acinetobacter spp.和P.putida等3个种群为主导并同时存在许多其他相似种,其中7个常见种的分离频率在不同稻区有显著差异。  相似文献   
132.
石油降解细菌的表型特性和系统发育分析   总被引:7,自引:0,他引:7  
从3种不同土壤中分离和纯化得到10个石油降解细菌菌株,分离菌株均为好氧菌、革兰氏阴性菌、不形成芽孢的杆菌,10个菌株均能利用中等链长的烷烃、柴油和原油作为碳源,而不能以单环芳烃和多环芳烃为碳源。根据其生理生化性状和16SrDNA序列分析结果表明,分离菌株EVA5,EVA6,EVA7,EVA8和EVA9为假单胞菌(Pseudomonas spp.),EVA10、EVA11、EVA12、EVA13和EVA14为不动杆菌(Acinetobacter spp.),均属于Proteobac-teria的γ亚群。  相似文献   
133.
The nitrogen (N) cycle is essentially 'leaky'. The losses of small amounts of nitrate to waters and of ammonia and nitrous oxide to the atmosphere are a part of the global biogeo-chemical N cycle. However, intensive agricultural production, industry and vehicle use have more than doubled the amount of 'reactive' N in the environment, resulting in eutrophication, ecosystem change and health concerns. Research has identified agricultural practices that cause large losses of N and, in some cases, developed solutions. This paper discusses the problems of maintaining productivity while reducing N losses, compares conventional with low input (integrated) and organic farming systems, and discusses wider options. It also looks at the need to integrate studies on N with other environmental impacts, set in the context of the whole farm system, to provide truly sustainable agricultural systems.  相似文献   
134.
135.
The ‘Monte Bosco clays and quartz sandstones’, cropping out at Baglio Beatrice near Castellammare del Golfo (Sicily, southern Italy) and belonging to the Pre-Panormide domain, contain planktic and nannofossil assemblages indicating the lower Oligocene, whereas reworked larger foraminifers occurring in turbidites are upper Eocene, and limestone clasts scattered throughout the section and occurring in channelized conglomerates are lower Eocene (Cuisian) in age. The autochthonous benthic foraminiferal assemblages in the hemipelagic marly clay background sediment indicate a well-oxygenated sea floor and show a deepening-upward trend through the succession from a middle to lower bathyal zone. Turbidites are graded and the coarser fraction, at the base of the beds, is composed by scattered tests of shallow-water late Eocene foraminifers reworked into the Oligocene matrix dominated by planktic foraminifers. The latter dominate the finer fraction characterized by the occurrence of quartz grains. The analysis of six limestone clasts revealed the occurrence of four microfacies characterizing a shallow-marine moderate-energy environment, a high-energy vegetated shoal, a high-energy middle-ramp, and the outer-ramp. The investigated clasts are all of a similar age, middle Cuisian, according to the microfossils, which include alveolinids, ornatorotaliids, and Cuvillierina vallensis. The interpreted microfacies suggest a distally steepened ramp source area, although there is no outcrop of such a platform in NW Sicily. The ‘Monte Bosco clays and quartz sandstones’ were deposited along a slope periodically affected by turbidity currents and debris flows, which cannibalized cemented and unlithified Eocene shallow-water carbonate facies.  相似文献   
136.
中国甘蓝型油菜遗传多样性的RAPD分子标记   总被引:24,自引:0,他引:24  
本文利用RAPD方法和统计学分析,对我国7省市和国外引进的总计40份甘蓝型油菜品种的遗传多样性进行了研究。结果表明,40个品种的甘蓝型油菜存在着广泛的遗传变异,根据RAPD指纹图谱,通过在DNA分子水平上的聚类分析可以将它们分为3大类群,反映出这些品种之间的亲缘关系,并对如何引进甘蓝型油菜资源进行了初浅的讨论。  相似文献   
137.
本文报导了金蛇王营养液(GKS)对老龄鼠细胞因子产生的影响。实验表明,细胞因子分泌功能下降的老龄鼠饲喂金蛇王营养液后,IL-2和IFN-r水平明显增加。进而证明金蛇王营养液是一种良好的免疫增强剂,能增强老龄机体抗肿瘤、抗感染等作用  相似文献   
138.
选用三种医用硅橡胶材料进行长期肉内植入试验。从方法学角对植入体形状,植入途径,包埋与切片方向,实验观察期,纤维包膜成分,评价指标等方面作了实验性探讨。  相似文献   
139.
Epipodophyllotoxin VP 16213 (4-demethyl-epipodophyllotoxin-β-D-ethylidene glucoside), given to 250 patients with various types of malignant disease, induced apparently complete remissions in four out of eight cases of acute monocytoid and acute myelomonocytoid leukaemia but only one complete regression and six incomplete remissions in 21 cases of reticulosarcoma. Incomplete regressions occurred in patients with Hodgkin''s disease, lymphosarcoma, melanoma, and carcinoma of the breast, ovary, testis, bladder, kidney, and thyroid. Seemingly complete regressions of malignant pleural effusion occurred when the drug was given systemically. Toxic side effects interfered with treatment in 40 patients but stopped it in only nine. No signs of toxicity were seen in 114 patients and in 85 the side effects were negligible. VP 16213 represents an advance in the treatment of acute monocytoid leukaemia, which has been up till now insensitive to any drug.  相似文献   
140.
Bleomycin alone was used in the treatment of 54 patients with Hodgkin''s disease in its later stages, 17 with generalized lymphosarcoma, 22 with reticulum cell sarcoma, and 7 with mycosis fungoides. The patients had had radiotherapy and full courses of conventional chemotherapy. Bleomycin was given in doses of 30 mg weekly to an average total dosage of 200 mg, though up to 800 mg could be given because of its marrow-sparing properties. Sixteen (29%) of the patients with Hodgkin''s disease remitted, most of them achieving only a partial remission, and similar results were obtained in the other three reticuloses. Bleomycin would seem to have some beneficial action in the late stages of Hodgkin''s disease, though it is less effective than some drug regimens recently introduced. Nevertheless it may be useful when there is diminished bone marrow reserve. It would be a suitable drug to use in combination therapy of these four reticuloses.  相似文献   
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