N2O-Freisetzung auf gemähtem Dauergrünland in Abhängigkeit von Standort und N-Düngung

N₂O Emissions from True Meadows Dependent on Location and N Fertilization Agricultural production is thought to be a main anthropogenic emitter of nitrous oxide (N₂O), which contributes to global warming and the destruction of the ozone layer. There is still considerable uncertainty about the amount of N₂O emission, and the site‐specific parameters that affect N₂O emission. From October 1995 until March 1998 experiments were conducted at established field plots (true meadows) at three different sites, i.e. low mountain range (Eifel), lowland (Niederrhein), and moist meadows (Münsterland). Plots were fertilized with calcium ammonium nitrate (CAN) at nitrogen equivalents ranging from 0 to 360 kg N ha^–1. N₂O fluxes were measured throughout the whole year using the closed‐chamber method. In addition, data on temperature, water‐filled pore space and precipitation were collected. N₂O emission rates (mg N₂O‐N ha^–1 h^–1) were highest either after fertilizer application or in winter during frost, depending on the experimental site and N dosage. The annual amount of N losses due to N₂O emission was dependent on the experimental site and the type and dosage of fertilizer. Disregarding the 360 kg N ha^–1 level of the CAN treatments, the N losses in this experiment were less than 1.5 kg N₂O‐N ha^–1 yr^–1. At low fertilizer dosage there was no reliable correlation between the amount of N that was applied and the amount of N₂O that was emitted. However, with high fertilizer levels the N₂O emissions increased gradually. Finally, N₂O emissions were more influenced by the amount of CAN than by the site.     

平湖剑子麦、洪湖大太宝、崇阳红麦、延岗坊主、万年2号抗赤霉病性基因分析

本试验将抗性组分分析法与单体分析法相结合,进行了小麦抗性基因染色体定位和抗性评价。结果表明,平湖剑子麦是抗性较稳定的中抗至抗病品种,其抗性基因涉及6D、7A、3B、5B和6B 等染色体。洪湖大太宝抗性基因和感病基因并存,是一个中抗偏感或中感品种。崇阳红麦属感病品种。延岗坊主的抗性基因位于染色体3A 上,感病基因位于5D 上,是一个中抗品种.万年2号麦穗前期抗病基因位于4D 和5A 上,是中抗品种。两种方法结合研究多基因控制的赤霉病抗性,能获得比较准确的结果和较多的遗传信息。     

农用车辆前轮定位失准的原因浅析及预防

针对农用车辆前轮定位失准的原因作出分析，并提出预防前轮定位失准的有效措施。     

Investigations on resistance of oats to Heterodera avenae: Location of resistance genes

Summary By using 15 available mono/nullisomic lines of Sun II back ground, the Heterodera avenae resistance gene in Nelson (from Avena sativa CI 3444) and Panema (from A. sterilis I. 376) were located on monosome XV. Genes with smaller effects were located on monosomes VIII and X. The absence of these genes derived from Sun II would increase cyst production on plants lacking major resistance genes.     

Chromosome locations of leaf rust resistance genes in selected tetraploid wheats through substitution lines

Langdon durum D-genome disomic substitution lines were used to study the chromosome locations of adult-plant leaf rust resistance genes identified from tetraploid wheat accessions. The accessions are 104 (Triticum turgidum subsp. dicoccum var. arras) and 127 (T. turgidum subsp. durum var. aestivum). The complete sets of the substitution lines were crossed as female parents with the accessions and F₁ double monosomic individuals selected at metaphase I. Segregating F₂ individuals were inoculated during the flag leaf stage with pathotype UVPrt2 of Puccinia triticina. The substitution analysis involving accession 104 showed that the gene for leaf rust resistance is located on chromosome 6B. The analysis with accession 127 indicated that chromosome 4A carries a gene for leaf rust resistance. The two novel genes are temporarily designated as Lrac104 and Lrac127, respectively from accessions 104 and 127.     

Production of a Trisomic Series in Hordeum vulgare cv. 'Golden Promise' and its Use in Locating a Recessive Chlorina Gene

A trisomic series was produced from a triploid plant of barley (Hordeum vulgare L. cv. ‘Golden Promise’) derived from tissue culture. Its characteristics are briefly described and compared with two trisomic series reported previously. Trisomic number 1 performed poorly under glasshouse conditions. Number 2 failed to set any seed after selfing and must be maintained by pollinating with ‘Golden Promise’. The series was subsequently used to locate a recessive chlorina gene on barley chromosome 3.     

Chromosomal location of genes controlling grain size in a large grained selection of wheat (Triticum aestivum L.)

Summary Grain size in wheat is the most stable yield component and has a favorable effect on flour yield. To identify the chromosomes associated with the large grains of line G603-86, (grain weight over 60 mg and grain length of about 9 mm), F₃ lines, extracted from F₂ populations obtained from F₁ monosomics of crosses between G603-86 (P₁) and the monosomic set of Favorit (P₂) were tested in the field. ANOVA showed significant differences among parents for grain weight and grain length, but not for grain width or the factor expressing the difference in grain form and density. Homoeologous groups had significant effects on grain weight and on all components of grain weight, while genomes were not significantly different for any of these characters. Grain weight was significantly increased by chromosomes 6D and 4A of G603-86. Grain length was significantly increased by chromosomes 4A, 4B, 2B, 3A and 1B, grain width by chromosomes 1A and 1B, and the factor form-density by chromosomes 6D and 6A. The high grain size in G603-86 results from the effects of genes located on many chromosomes which affect grain dimensions, form and density.     

Decision Model for Location Selection of the Resident Project

Started with studying the evaluation standard, which are influencing the decision for location selection of the resident project, this paper set up a decision model for the location selection. It confirmeds evaluation rule of the location selection according to the characteristic of the resident project and selects all the location by fuzzy mathematic and AHP. After this selection, AHP is used again to taxis all the suitable location to build in the most suitable place. This model is provided with a scientific and rational decision result in the location selection for companies of the real estate.     

Location of genes for chlorophyll synthesis on specific arms of chromosomes in Triticum aestivum

Summary An Indian hexaploid wheat var. Pb C591 has been shown to carry gene(s) for chlorophyll synthesis on chromosome 3A (Singh & Joshi, 1979). In the present study cv. Pb.C591, its monosomic 3A and diteocentrics for 3A, 3BL and 3DL of var. Chinese Spring have been used. The F₂ segregation involving crosses between Pb.C591 as male, monosomic line 3A of Pb.C591 (female) and ditelocentrics 3A, 3BL and 3DL of cv. Chinese Spring as male and female respectively has been observed. It has been found that there are two dominant genes regulating chlorophyll synthesis in cv. Chinese Spring. These genes are located on chromosomes arms 3A and 3DS respectively.These chlorophyll synthetic genes must be the same which were postulated by Sears (1956, 1957) as the normal alleles of virescent gene v ₂ (which was located on 3BS) on chromosomes 3A(v ₁) and 3D(V ₃).     

稻麦“双套”轻型简化栽培技术的研究及应用(Ⅰ) ——淮北地区稻棵套播麦的生育特点及栽培对策

系统论述了淮北地区稻棵套播麦播期提前，利于早发壮苗；群体大，高峰苗提前，利于足穗形成；幼苗发育进程提前，利于大穗形成的生育特点，及限制穗、粒、重三因素协调发展相关影响机理，提出了选用抗病品种、适期适量播种、“少食多餐”的平衡施肥方式、冬前保持地表土壤良好环境等配套轻型简化栽培技术，在生产实践中应用，取得了较好的经济效益和社会效益。