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991.
新收获小麦在储藏过程中品质变化规律的研究   总被引:15,自引:0,他引:15  
万安平  金丽 《粮食储藏》1999,28(2):31-36
本文以陕优225和CA864小麦为材料,研究了小麦在储藏过程中的品质变化规律。结果表明,在储藏过程中小麦籽粒硬度,蛋白质含量及面筋含量基本保持不变。随着储藏时间的延长,小麦的出粉率明显提高,面团的流变学行性逐步改善,具体表面在面团稳定时间和谰价仪值有所增加,公差指数明显下降,面团的延伸性逐渐减弱,最大抗延伸阻力逐渐增大,抗/延比值和面积都明显增大,作为小麦品质最佳代表指标的SDS-沉降值在储藏过程  相似文献   
992.
南疆维吾尔族教育的发展,既凝聚着本民族的智慧与哲理,又是在汉文化、佛教文化与伊斯兰文化等多种因素综合作用下的演变过程。简言之,南疆维吾尔族教育,以汉文儒学教育、佛教寺院教育、伊斯兰经文教育为源流,在文化融合的广阔背景下持续发展,至新中国成立后进入崭新的历史发展时期。  相似文献   
993.
Canine brucellosis is a contagious disease with venereal and oral modes of transmission that produces late abortion in females, epididymides and prostates in males. Diagnosis is difficult because of unstable serum antibody titers that vary from individual to individual as well as between different methods used for their detection. The objective of this work was to evaluate the clinical utility of the immunochromatographic assay (ICA) for serodiagnosis of dogs suspected of having brucellosis, and results were compared with those obtained for hemoculture (HC) and the rapid screening agglutination with 2-mercaptoethanol (2-ME RSAT). The all experimentally infected dogs were positive in ICA, HC and 2-ME RSAT from 5 weeks, 7 weeks, and 3 weeks after infection, respectively. Also, among dogs selected from 10 different breed kennels occurred brucellosis, 24.8%, 39.5% and 39.1% of dogs tested were detected as positive with HC, 2-ME RSAT and ICA, respectively. The kappa value between 2-ME RSAT and ICA was 0.89. The results of this study showed that sensitivity and specificity of the ICA are comparable with those obtained using conventional serological and bacteriological test for brucellosis. In conclusion, the ICA kit provides a handy and accurate tool for the rapid serodiagnosis of canine brucellosis.  相似文献   
994.
The role of behavioral mechanisms in animal invasions is poorly understood. We show that asymmetric mating interactions between closely related but previously allopatric genetic groups of the whitefly Bemisia tabaci, a haplodiploid species, have been a driving force contributing to widespread invasion and displacement by alien populations. We conducted long-term field surveys, caged population experiments, and detailed behavioral observations in Zhejiang, China, and Queensland, Australia, to investigate the invasion process and its underlying behavioral mechanisms. During invasion and displacement, we found increased frequency of copulation leading to increased production of female progeny among the invader, as well as reduced copulation and female production in the indigenous genetic groups. Such asymmetric mating interactions may be critical to determining the capacity of a haplodiploid invader and the consequences for its closely related indigenous organisms.  相似文献   
995.
在我国渐进式改革和市场转型过程中,"三农"问题已经突破经济层面,成为一个综合性的社会问题.解决三农问题,必须按照社会主义的本质要求,站在市场经济的最高处,站在"最广大人民"利益的最高处,用发展的全局的眼光和思维,制定设计出符合农民长远利益的系统性战略性策略措施和改革方案.标本兼治,循序渐进,逐步实现农民的权益.  相似文献   
996.
  1. Gonadotropin-releasing hormone (GnRH), a neuropeptide, plays a vital role in the hypothalamus–pituitary–gonadal (HPG) axis. In vertebrates, GnRH is crucial for the onset of sexual development and the entire reproductive process. The purpose of this study was to identify genetic factors associated with egg-laying traits of Muscovy ducks.

  2. The full-length cDNA (474 bp) of Muscovy duck GnRH was obtained and characterised. It encodes 92 amino acids containing a 1-amino acid signal peptide cleavage site. Phylogenetic analysis revealed that Muscovy duck GnRH has a close relationship with Anas platyrhynchos GnRH.

  3. GnRH showed significantly different expression profiles between 4 developmental periods in the hypothalamus, pituitary, and ovary. The expression of GnRH in the laying period (36 weeks) was higher than at other periods in the three tissues. GnRH was widely expressed in 12 examined tissues of nesting and laying Muscovy ducks. In the hypothalamus, pituitary and gonads, the expression of GnRH was higher than in other tissues.

  4. In laying Muscovy ducks, the expression of GnRH in the hypothalamus, pituitary, ovary, muscular stomach, pancreas, heart, duodenum and spleen was significantly higher than in nesting dusks. Differences were detected in the liver and glandular stomach between laying ducks and nesting ducks. Differences between the kidney and lung were not significant.

  5. In the pituitary, the GnRH and GnRH receptor (GnRHR) genes shared the same expression profiles during 4 time points. Both genes had the highest expression at 36 weeks of age.

  6. A mutation (g.206G > A) in the 5?-flanking region was associated with egg-laying performance. Individuals with genotype GG had better egg-laying performance than the individuals with genotype AA. GnRH may be used as a marker gene for laying performance in the Muscovy duck.

  相似文献   
997.
以2种花色、花型良好,长势优异的雄性不育百合'5-4,与'5-35,为试材,采用组织培养法,研究不同消毒时间、激素浓度及不同基质配比对2种雄性不育百合组织培养过程中的影响,以期建立快速繁殖体系,为无花粉百合的大量生产提供参考依据.结果表明:最佳外植体灭菌方式为75%乙醇消毒20 s,10%NaClO处理8 min,和75%乙醇消毒30 s,10%NaClO处理6 min;最佳诱导培养基为 MS+NAA 1.0 mg·L-1+6-BA 0.5 mg·L-1和 MS+NAA 1.5 mg·L-1+6-BA 0.5 mg·L-1;最佳增殖培养基均为 MS+6-BA 1.5 mg·L-1+NAA 0.5 mg·L-1;最佳生根培养基为 1/2MS+IBA 0.1 mg·L-1+NAA 0.1 mg·L-1+蔗糖40 g·L-1 和 1/2MS+IBA 0.2 mg·L-1+NAA 0.1 mg·L-1+蔗糖40 g·L-1;最佳移栽基质比例为蛭石:珍珠岩:草炭=1 ∶1∶1.  相似文献   
998.
介绍了软籽石榴类型的界定,概述了中国软籽石榴的品种、类型及其来源,总结了中国软籽石榴产业发展现状和存在问题,提出了发展建议。  相似文献   
999.
丘陵双季稻机械化生产高产栽培技术研究   总被引:1,自引:0,他引:1  
研究旨在探索机械化生产条件下的丘陵双季稻区水稻高产栽培技术。以10个早、晚稻品种为材料,设置高(H)、中(M)、低(L)3个施肥水平,比较分析不同处理条件下的秧苗素质、茎蘖动态、干物质量、产量和产量结构。研究结果表明:产量较高的水稻品种其秧苗素质较高,各处理茎蘖数的动态变化均呈单峰曲线,茎蘖数、叶和茎的干物质量随施肥量的增加而增大,穗的干物质量、收获指数和产量均以M施肥水平的最大,其产量比H和L施肥水平分别平均增产446.74 kg/hm2和872.16 kg/hm2,增幅分别为6.79%和14.18%。  相似文献   
1000.
The diatom Phaeodactylum tricornutum can accumulate eicosapentaenoic acid (EPA) up to 30% of the total fatty acids. This species has been targeted for isolating gene encoding desaturases and elongases for long-chain polyunsaturated fatty acid (LC-PUFA) metabolic engineering. Here we first report the cloning and characterization of Δ5-elongase gene in P. tricornutum. A full-length cDNA sequence, designated PhtELO5, was shown to contain a 1110 bp open reading frame encoding a 369 amino acid polypeptide. The putative protein contains seven transmembrane regions and two elongase characteristic motifs of FLHXYHH and MYSYY, the latter being typical for microalgal Δ5-elongases. Phylogenetic analysis indicated that PhtELO5 belongs to the ELO5 group, tightly clustered with the counterpart of Thalassiosira pseudonana. Heterologous expression of PhtELO5 in Pichia pastoris confirmed that it encodes a specific Δ5-elongase capable of elongating arachidonic acid and eicosapentaenoic acid. Co-expression of PhtELO5 and IsFAD4 (a ∆4-desaturase from Isochrysis sphaerica) demonstrated that the high-efficiency biosynthetic pathway of docosahexaenoic acid was assembled in the transgenic yeast. Substrate competition revealed that PhtELO5 exhibited higher activity towards n-3 PUFA than n-6 PUFA. It is hypothesized that Phaeodactylum ELO5 may preferentially participate in biosynthesis of transgenic LC-PUFA via a n-3 pathway in the yeast host.  相似文献   
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