夏秋蚕新品种浒花、秋星的育成及其一代杂交种的选配     

何毅  司马杨虎 《蚕业科学》1991,17(4):200-207

根据长江流域夏秋季的气候特点,采用杂交、回交、系统分离、活蛹缫丝和多代高温多湿环境定向培育等育种方法,分别育成了中系蚕品种“浒花”和日系蚕品种“秋星”。两者都具有抗性强、丝量高、茧丝质优以及繁育容易等特点。其一代杂交种经多次实验室鉴定、农村生产鉴定、试养以及全国蚕品种审定结果表明:该新品种体质强健、孵化、眠起、老熟齐一,茧丝量高,茧层率22％;鲜毛茧出丝率15—16％,茧丝品质优良、解舒率74％,净度93分,茧丝纤度2.53/D,茧丝长超1000m。  相似文献   

家蚕EST数据库的应用现状及展望     

蔡明文房丽秀  司马杨虎 《江苏蚕业》2007,29(3):9-12

家蚕是重要的经济昆虫,也是鳞翅目昆虫的主要模式生物。表达序列标签(EST)在家蚕研究中的应用越来越受到关注。本文主要介绍了EST数据库的建立及其在家蚕研究中的应用现状,展望了EST在家蚕中的研究趋势。  相似文献   

盐酸处理蚕卵酯酶A4的活性变化及其与滞育性的关系   总被引：10，自引：6，他引：4  

徐世清  甲斐英则 《蚕业科学》1998,24(2):95-99

从家蚕C108品种蚕卵精制酯酶A4,首次测定了产卵后24～96h浸酸蚕卵酯酶A4的ATPase活性。蚕卵经盐酸处理后在体外5℃1～2d或体外25℃1～3h出现酶活性峰。与低温活化蚕卵比较,产卵后24～96h的浸酸蚕卵,在体外5℃酶活性峰出现时间提早了8．5～22d,在体外25℃提早了3～9h。浸酸后蚕卵迅速解除滞育,滞育发育时间显著缩短。将不同卵龄未浸酸蚕卵与盐酸处理蚕卵酯酶A4的ATPase活性峰出现时间差制成曲线,在体外5℃或25℃的结果几乎都完全与5℃冷藏时蚕卵的滞育发育时间曲线重叠。盐酸处理蚕卵酯酶A4的活性变化与蚕卵活化有高度相关性。  相似文献   

Analysis of HLA-G gene expression in B-lymphocytes from chronic lymphocytic leukemia patients   总被引：1，自引：0，他引：1  

Rezvany MR  Kazemi A  Hajifathali A  Kaviani S  Mellstedt H 《Iranian Biomedical Journal》2007,11(2):125-129

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Effect of Baythroid on nitrogen transformations in soil     

A. Lodhi  F. Azam  N. N. Malik 《Biology and Fertility of Soils》1994,17(3):173-176

Laboratory incubation experiments were conducted in soil to study the influence of the insecticide Baythroid on immobilization-remineralization of added inorganic N, mineralization of organic N, and nitrification of added NH _inf4 ^su+ -N. Baythroid was applied at 0, 0.4, 0.8, 1.6, 3.2, and 6.4 g g^-1 soil (active ingredient basis). The treated soils were incubated at 30°C for different time intervals depending upon the experiment. The immobilization and mineralization of N were significantly increased in the presence of Baythroid, the effect being greater with higher doses of the insecticide. Conversely, nitrification was retarded at lower doses of Baythroid and significantly inhibited at higher doses. The results of these studies suggest that excessive amonts of insecticide residues affect different microbial populations differently, leading to changes in nutrient cycling.  相似文献   

Oceanography. Microbes, molecules, and marine ecosystems     

Azam F  Worden AZ 《Science (New York, N.Y.)》2004,303(5664):1622-1624

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Fate and interaction with native soil N of ammonium N applied to wetland rice (Oryza sativa L.) grown under saline and non-saline conditions     

F. Azam  M. Asharf  A. Lodhi  M. I. Sajjad 《Biology and Fertility of Soils》1992,13(2):102-107

Summary The effect of salts on the balance of fertilizer N applied as ¹⁵N-labelled ammonium sulphate and its interaction with native soil N was studied in a pot experiment using rice (Oryza sativa L.) as a test crop. The rice crop used 26%–40% of the applied N, the level of applied N and salts showing no significant bearing on the uptake of fertilizer N. Losses of fertilizer N ranged between 54% and 68% and only 5%–8% of the N was immobilized in soil organic matter. Neither the salts nor the rate of N application had any significant effect on fertilizer N immobilization. The effective use of fertilizer N (fertilizer N in grain/fertilizer N in whole plant) was, however, better in the non-saline soil. The uptake of unlabelled N (N mineralized from soil organic matter and that originating from biological N₂ fixation in thes rhizosphere) was inhibited in the presence of the salts. However, in fertilized soil, the uptake of unlabelled N was significantly enhanced, leading to increased A values [(1-% Ndff/% Ndff)x N fertilizer applied, where Ndff is N derived from fertilizer], an index of interaction with the added N. This added N interaction increased with increasing levels of added N. Since the extra unlabelled N taken up by fertilized plants was greater than the fertilizer N immobilized, and the root biomass increased with increasing levels of added N, a greater part of the added N interaction was considered to be real, any contribution by an apparent N interaction (pool substitution or isotopic displacement) to the total calculated N interaction being fairly small. Under saline conditions, for the same level of fertilizer N addition, the added N interaction was lower, and this was attributed to a lower level of microbial activity, including mineralization of native soil N, rootdriven immobilization of applied N, and N₂ fixation.  相似文献   

Release, movement and recovery of 3,4-dimethylpyrazole phosphate (DMPP), ammonium, and nitrate from stabilized nitrogen fertilizer granules in a silty clay soil under laboratory conditions   总被引：8，自引：0，他引：8  

F. Azam  G. Benckiser  C. Müller  J. Ottow 《Biology and Fertility of Soils》2001,33(2):118-125

 The composition of soil microbiota in four heated (350  °C, 1 h) soils (one Ortic Podsol over sandstone and three Humic Cambisol over granite, schist or limestone) inoculated (1.5 μg chlorophyll a g^–1 soil or 3.0 μg chlorophyll a g^–1 soil) with cyanobacteria (Oscillatoria PCC9014, Nostoc PCC9025, Nostoc PCC9104, Scytonema CCC9801, and a mixture of the four) was studied by cultural methods. The aims of the work were to investigate the potential value of cyanobacteria as biofertilizers for accelerating soil recolonization after fire as well as promoting microbiotic crust formation and to determine the microbial composition of such a crust. The inoculated cyanobacteria proliferated by 5 logarithmic units in the heated soils which were colonized very quickly and, after 2 months of incubation, the cyanobacterial filaments and associated fungal hyphae made up a matrix in which surface soil particles were gathered into crusts of up to 1.0 cm in thickness. These crusts were composed, on average, of 2.5×10¹⁰ cyanobacteria, 2.8×10⁶ algae, 6.1×10¹⁰ heterotrophic bacteria (of which 1.2×10⁸ were acidophilic, 1.3×10⁶ were Bacillus spp. and 1.5×10⁸ were actinomycetes) and 77.8 m fungal mycelium (1.4×10⁶ were fungal propagules) g^–1 crust. Counts of most microbial groups were positively correlated to cyanobacterial numbers. The efficacy of treatment depended on both the class of inoculum and the type of soil. The best inoculum was the mixture of the four strains and, whatever the inoculum used, the soil over lime showed the most developed crust followed by the soils over schist, granite and sandstone; however, the latter was comparatively the most favoured by the amendment. In the medium term there were no significant differences between the two inocula rates used. Biofertilization increased counts of cyanobacteria by 8 logarithmic units while heterotrophic bacteria, actinomycetes, algae and fungal propagules rose by >4 logarithmic units, acidophilic bacteria and Bacillus spp. by around 3 logarithmic units and fungal mycelia showed an 80-fold increase. The results showed that inoculation of burned soils with particle-binding diazotrophic cyanobacteria may be a means of both improving crust formation and restoring microbial populations. Received: 8 March 2000  相似文献   

Comparative effects of applying leguminous and non-leguminous green manures and inorganic N on biomass yield and nitrogen uptake in flooded rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)     

M.?AshrafEmail author  T.?Mahmood  F.?Azam  R.?M.?Qureshi 《Biology and Fertility of Soils》2004,40(2):147-152

The beneficial role of green manures in rice production is generally ascribed to their potential of supplying plant nutrients, particularly nitrogen (N). However, the mechanisms through which green manures enhance the crop productivity are poorly understood. Pot experiments were conducted using a ¹⁵N-tracer technique: (1) to compare the biomass production potential of sesbania (Sesbania aculeata Pers.) and maize (Zea mays L.) as green manuring crops for lowland rice and (2) to compare the effect of the two types of green manure and inorganic N on the dry matter accumulation and N uptake by two rice (Oryza sativa L.) cultivars, viz. IR-6 and Bas-370. Although maize produced three times higher shoot biomass compared with sesbania, the latter showed higher N concentration; and thus the total N yield was similar in the two types of plants. Applying the shoot material of the two plants to flooded rice significantly enhanced the dry matter yield and N uptake by the two rice cultivars, the positive effects generally being more pronounced with sesbania than with maize amendment. The difference in the growth-promoting potential of the two plant residues was related more to an increased uptake of the native soil N rather than to their direct role as a source of plant-available N. A positive added nitrogen interaction (ANI) was observed due to both plant residues, the effect was much more pronounced with the application of sesbania than with maize residues. In both rice cultivars, inorganic N also caused a substantial ANI, particularly at higher application rate. Losses from the applied N were 2–3 times lower from sesbania, compared with maize treatment. Green manuring with sesbania also caused much lower N losses than the inorganic N applied at equivalent or higher rates. The overall benefit of green manuring to rice plants was higher than inorganic N applied at comparable rates. The two rice cultivars differed in their response to green manuring, IR-6 generally being more responsive than Bas-370.  相似文献   

    

F. Azam 《Biology and Fertility of Soils》2006,42(6):577

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