利用SSR标记分析川育12×人工合成小麦Syn780重组自交系群体中的偏分离现象

利用栽培小麦“川育12”和“硬粒小麦—节节麦人工合成小麦”Syn780杂交得到的F8代重组自交系,对103个SSR分子标记的偏分离现象进行了分析,结果表明,22.3%的位点出现偏分离,发生偏分离的标记主要集中分布在A染色体组。为进一步利用该重组自交系标记双亲重要性状提供了参考信息。     

浅析会计信息失真及治理对策

作者对会计信息失真及治理对策的有关问题,提出了几点建议,可供有关人员参考。     

混合多电平逆变器拓扑及调制方法

针对传统多电平逆变器需要的开关器件数量较多,输出电压谐波较大等问题,该文提出了一种非对称混合多电平逆变器拓扑,包括二极管钳位非对称多电平逆变器和电压源串并联状态切换的H桥多电平逆变器。在输出电压电平数相同的情况下,该逆变器拓扑能减少开关器件的数量。采用与混合多电平逆变器相适应的混合调制控制策略,该策略使大部分开关器件工作在低频状态,减少了开关损耗,避免了电流倒流,降低了输出电压的总谐波失真(THD),可以实现连续PWM调幅。通过仿真,验证了该逆变器拓扑及其调制策略的正确性。     

Mixed Inheritance of Equine Recurrent Airway Obstruction

Background: Mode of inheritance of equine recurrent airway obstruction (RAO) is unknown.
Hypothesis: Major genes are responsible for RAO.
Animals: Direct offspring of 2 RAO-affected Warmblood stallions (n = 197; n = 163) and a representative sample of Swiss Warmbloods (n = 401).
Methods: One environmental and 4 genetic models (general, mixed inheritance, major gene, and polygene) were tested for Horse Owner Assessed Respiratory Signs Index (1–4, unaffected to severely affected) by segregation analyses of the 2 half-sib sire families, both combined and separately, using prevalences estimated in a representative sample.
Results: In all data sets the mixed inheritance model was most likely to explain the pattern of inheritance. In all 3 datasets the mixed inheritance model did not differ significantly from the general model ( P = .62, P = 1.00, and P = .27) but was always better than the major gene model ( P < .01) and the polygene model ( P < .01). The frequency of the deleterious allele differed considerably between the 2 sire families ( P = .23 and P = .06). In both sire families the displacement was large ( t = 17.52 and t = 12.24) and the heritability extremely large ( h ²= 1).
Conclusions and Clinical Relevance: Segregation analyses clearly reveal the presence of a major gene playing a role in RAO. In 1 family, the mode of inheritance was autosomal dominant, whereas in the other family it was autosomal recessive. Although the expression of RAO is influenced by exposure to hay, these findings suggest a strong, complex genetic background for RAO.     

GPS测量技术研究

本文针对ＧＰＳ测量实际工作中，影响ＧＰＳ测量的成果质量和工效的因素进行了分析研究，并提出解决的办法。对完善ＧＰＳ测量的技术和方法，具有一定的指导意义。     

卧式水泥窑窑体安装工法

水泥窑是水泥生产装置的核心设备,其安装难度较大,质量要求较高,特别是窑体安装的直线度和窑体的焊接变形是水泥窑安装控制的关键,本文就黑龙江省桦南县鸿基水泥厂2500t/d水泥窑安装工程进行介绍水泥窑窑体的安装工法,供参考。     

墨辊变形对印刷品质量的影响

墨辊在化学、物理和机械的相互作用下，发生性能和形状的改变，使印刷中的墨层厚度控制更加复杂，进而影响到印刷品的质量．对失效的墨辊提出了新的修复方法，延长了墨辊的使用寿命．     

Safe Monitor and Analysis of Deep Excavation with Total Station

During the process of deep excavation digging,it is an important task to monitor the excavation and affected building to make sure the spot's safety and go on wheels with the schedule.In this article some causation of slip and the calculation methods of freely setting station are first discussed,and then combined with the theory of polar coordinates a forecast method through distortion course curve analysis is put forward.The method with its low cost and speediness,can satisfy the precision requirement and provide the base data for safe evaluating and designing.     

Molecular and agronomic evaluation of wheat doubled haploid lines obtained through maize pollination and anther culture methods

Although maize pollination (MP) and anther culture (AC) are alternative techniques widely used for wheat doubled haploid (DH) production, there is only limited information on the attributes of the plant materials produced through both methods. This study was conducted to evaluate genetic fidelity, transmission of parental gametes, and to compare field performance of DH populations produced by the MP and AC methods from the F1s of two crosses between spring bread wheat cultivars. The DH populations were compared to single seed descent (SSD) lines created from the same crosses. In total, 76 MP and 122 AC lines of the cross between cultivars of divergent origin were subjected to RAPD and AFLP analysis. Only changes in AFLP banding patterns, at similarly low frequencies, 0.18% (MP) and 0.21% (AC), were detected. The frequency of the DH lines affected by the variation, 14.5% (MP) and 14.8% (AC), was similar in both populations. For most of the DH lines, variation in 1‐2 loci only, out of several hundreds scored, was observed. A total of 14.3% (MP) and 22.2% (AC) marker loci showed the significant segregation distortion from the expected 1 : 1 ratio, but in at least one polymorphic locus the within‐cultivar variation was responsible for the skewed segregation. The field performance of the corresponding MP and AC lines derived from two crosses confirmed the equivalency of both DH populations. In most of the traits analyzed, the MP and AC lines performed the same as the SSD populations created from the same crosses. No, or very small differences in means and ranges, were observed when the best 10% of the lines from all three methods were compared. Moreover, the best 10 % of the lines of the cross between Polish wheat cultivars adapted to the local environment performed significantly better for some traits than different groups of checks used in the study.     

Mapping the GA3-insensitive dwarfing gene ct1 on chromosome 7 in rye

A gibberellic acid-insensitive dwarfing gene in rye (ct1) was mapped in an F₂ population on chromosome 7R close to the centromere. Two RFLP markers were found, which flank the gene at distances of 1 and 3 cM, respectively. A total of 11 markers were mapped on 7R of which six cluster around the centromere and show segregation distortion in the case of the codominant markers. The ct1 gene is closely linked to copies of both α-amylase and EmBP, as is the ct2 gene on chromosome 5R. Because of the different chromosomal locations of the GA₃-insensitive dwarfing genes in rye and wheat it is concluded that these genes are not homoeologous. This is supported by further differences in their phenotypic and genotypic expressions.