Greenhouse gas emissions in response to straw incorporation,water management and their interaction in a paddy field in subtropical central China

A field experiment was conducted to study the effects of combination of straw incorporation and water management on fluxes of CH₄, N₂O and soil heterotrophic respiration (Rh) in a paddy field in subtropical central China by using a static opaque chamber/gas chromatography method. Four treatments were set up: two rice straw incorporation rates at 0 (S1) and 6 (S2) t ha^?1 combined with two water managements of intermittent irrigation (W1, with mid-season drainage) and continuous flooding (W2, without mid-season drainage). The cumulative seasonal CH₄ emissions for the treatments of S1W2, S2W1 and S2W2 increased significantly by 1.84, 5.47 and 6.63 times, respectively, while seasonal N₂O emissions decreased by 0.67, 0.29 and 1.21 times, respectively, as compared to S1W1 treatment. The significant increase in the cumulative Rh for the treatments S1W1, S2W1 and S2W2 were 0.54, 1.35 and 0.52 times, respectively, in comparison with S1W2. On a seasonal basis, both the CO₂-equivalents (CO₂e) and yield-scaled CO₂e (GHGI) of CH₄ and N₂O emissions increased with straw incorporation and continuous flooding, following the order: S2W2>S2W1>S1W2>S1W1. Thus, the practices of in season straw incorporation should be discouraged, while mid-season drainage is recommended in paddy rice production from a point view of reducing greenhouse gas emissions.     

Molecular cloning and functional analysis of duck Toll-like receptor 5

Toll-like receptor 5 (TLR5) is responsible for the recognition of bacterial flagellin in vertebrates. In this study, we cloned the single-exon TLR5 gene of the Maya breed of Common Shelduck (Tadorna tadorna). The TLR5 open reading frame is 2580 bp in length and encodes an 859-amino acid protein. The putative amino acid sequence of duck TLR5 consisted of a signal peptide sequence, 11 leucine-rich repeat domains, a leucine-rich repeat C-terminal domain, a transmembrane domain, and an intracellular Toll-interleukin-1 receptor domain. The duck TLR5 gene was highly expressed in the lung, bone marrow, spleen, and liver; moderately expressed in kidney, small intestine, large intestine, and brain. A plasmid expressing duck TLR5 was constructed and transfected into HEK293T cells, and expression was confirmed by indirect immunofluorescence assay. HEK293T cells transfected with duck TLR5- and NF-κB-luciferase-containing plasmids significantly responded to flagellin from Salmonella typhimurium, indicating that it is a functional TLR5 homolog.     

油菜硫甙的农业生态学意义与研究进展

论述了油菜琉甙(即琉代葡萄糖甙)的组分、主要生理功能及其含量过高对家畜的不利影响以及引种国际油菜导致的生态问题,指出了影响油菜硫甙含量的主要因素、油菜琉甙对维护十字花科植物抗性的自身保护功能、生态学意义及其发展应用潜力。     

基于键合图理论的动力稳定装置轮轨间动态特性分析

考虑动力稳定装置的轮轨非线性接触、轮轨间的间隙传动、夹钳油缸和水平油缸的等效刚度建立了动力稳定装置动态特性键合图模型.使用分段函数表达式实现了轮轨间的间隙传动.针对不同夹持力对于能量的传递效率与作业效果进行了深入分析与探究,确定了所需最小的水平油缸的推力.     

Immune responses in piglets infected with highly pathogenic porcine reproductive and respiratory syndrome virus

Porcine reproductive and respiratory syndrome virus (PRRSV) infection compromises the host's innate and adaptive immunity. The aim of this study was to investigate the immune responses of piglets infected with highly pathogenic (HP) PRRSV (HuN4 strain) with or without the immunization with CH-1R attenuated PRRSV vaccine. The response was evaluated for the clinical signs, pathological changes and virus load in immune organs, antibody responses and levels of serum IFN-γ, IL-4 and IL-10. The result showed that in comparison with the piglets received the immunization, the piglets infected with HP-PRRSV alone had the thymus atrophy, decreased serum levels of IL-4 and increased serum levels of IL-10 and INF-γ. These results suggest that elevated IL-10 levels at the early stage of the infection may enhance virus survival and delay the induction of protective immunity, while increased levels of IL-4 induce the effective immune responses and increase the animals' health status.     

东方百合L_sCCR1基因的克隆及表达分析

百合茎秆的挺度直接关系到百合花采收后的货架寿命等重要商品性状,而这些商品性状与植物茎秆中的木质素的含量高低有关.本文应用RLM-RACE技术,从东方百合索蚌植株中克隆了木质素合成相关基因一肉桂酰辅酶A还原酶,定名为LsCCR1.该基因cDNA全长为1 499 bp,包括完整的阅读框,编码388个氨基酸.多重比对分析发现百合LsCCR1基因与其他植物上已经发现的CCR基因同源性多介于55%～66%之间.利用半定量PCR检测LsCCR1基因在百合不同组织中的表达差异,结果显示LsCCR1基因主要在百合的茎秆中表达,根部次之,叶片、鳞茎及花蕾中表达量较少,其表达模式与拟南芥、桉树及大麦中CCR基因的表达模式类似.     

芦荟饮料褐变的控制研究

研究了芦荟凝胶在制汁过程及芦荟饮料在加工过程中温度和时间等因数对芦荟饮料色泽的影响。结果表明,搅汁时间10min,杀菌温度85℃,杀菌时间25min是有效控制芦荟饮料褐变的最佳工艺参数。