本试验旨在研究日粮中添加富含缩合单宁（CT）[18.9 g kg^-1 干物质（DM）]的高粱对肉牛氮（N）代谢和尿液氧化亚氮（N₂O）排放的影响。试验1选用6头利木赞×鲁西杂交阉牛（初始体重为245 ± 18.70 kg）作为试验动物，采用有重复的3×3拉丁方试验设计，日粮中高粱含量分别为0、167和338 g kg^-1 DM。试验2采用静态土壤培养技术测定试验1中尿样的N₂O排放量。试验1的结果表明，日粮中添加高粱线性增加了粪N排泄量（P=0.001）、总N排泄量（P=0.010）和粪N/采食N比例（P=0.021），但没有影响尿N排泄量、沉积N和N沉积率（P>0.10）。血浆代谢组学数据显示，日粮中添加高粱上调了酚酸（N1,N5,N10-tris-trans-p-coumaroylspermine and prenyl cis-caffeate）和肉碱（3-hydroxyisovalerylcarnitine and linoelaidyl carnitine）的相对浓度。试验1的结果还显示，随着日粮中高粱比例的提高，肉牛的尿素排泄量线性增加（P=0.001），尿囊素排泄量有线性降低的趋势（P=0.051），尿液嘌呤衍生物排泄量（P=0.041）及根据尿液嘌呤衍生物估测的瘤胃微生物N流量线性降低（P=0.012）。试验2的结果表明，随着日粮中高粱比例的提高，土壤的整个培养期的平均pH没有显著变化（P>0.10），但是土壤NH₄⁺-N（P=0.012）、NO₂^--N（P=0.009）、NO₃^--N（P=0.001）和无机N（P<0.001）的平均浓度线性提高。土壤静态培养的结果还显示，随着日粮中高粱比例的提高，尿液N₂O-N排放量（P=0.001）、N₂O-N排放/尿N施加量比例（P=0.038）和尿液N₂O-N估测排放量（P=0.021）均线性提高。综上所述，日粮中添加富含CT的高粱167 和 338 g kg^-1 DM不影响肉牛的N沉积率，但可增加尿液N₂O-N排放量分别达5.7%和31.4%。为了减少向环境中排放的氧化亚氮数量，不建议在肉牛日粮中添加高水平的高粱。

脱落酸（ABA）在促进植物生长发育以及介导植物对不利环境刺激的反应方面发挥着关键作用。为了探究ABA在缓解番茄低温胁迫中的作用，我们检测了低温（LT）胁迫后野生型番茄RR、ABA缺失突变体sitiens（sit）和ABA预处理的sit幼苗的光合能力。结果发现，低温胁迫下，sit幼苗的净光合速率、胞间二氧化碳浓度、蒸腾速率和气孔导度低于RR幼苗。sit幼苗的叶绿体宽度、面积和嗜锇颗粒数量显著大于RR幼苗，并且sit幼苗的叶绿体长宽比显著低于RR幼苗。低温胁迫后，sit幼苗的光化学活性降低，光合作用相关基因的表达发生改变。ABA预处理显著缓解了上述现象。我们还进行了RNA-seq，并分析了低温胁迫后番茄幼苗中基因的表达模式。我们总共构建了15个cDNA文库，并鉴定了参与光合作用、植物激素信号转导以及初级和次级代谢的差异表达基因。我们分析了参与光合作用相关过程的转录因子和基因，筛选到了转录因子WRKY22和光合基因PsbA。萤光素酶报告基因试验和电泳迁移率偏移试验证实WRKY22调节PsbA的表达。低温胁迫后WRKY22和PsbA沉默植株的PSII受到抑制。我们的研究结果表明，在低温胁迫下，ABA通过WRKY22–PsbA在调节番茄光合作用和保护PSII中发挥作用。

本研究从中国鸭中分离出一株高致病性且多重耐药的多杀性巴氏杆菌（Pasteurella multocida，PM）HN141014。基于HN141014的全基因组生物信息学分析及共轭转移试验，鉴定出一种新型的多重耐药整合接合元件（ICEPmu3）。该元件属于ICEHin1056亚家族，具有种内种间转移特性，包含除tfc1和tfc20外几乎完整的Ⅳ型分泌系统，携带tetR(B)-tet(B)-tetC、aph(3ʹ)-Ia和sul2-strA-strB等多种耐药基因。进一步分析发现，ICEPmu3还存在于亚洲和美洲源的其他3株PM和8株禽类芽孢杆菌中。这些结果表明ICEPmu3的出现和流行可能会加剧养禽业中PM的防控难度。

探究影响牛肉品质的遗传因素和代谢物分子对提高牛肉品质和满足消费者需求至关重要。肉牛不同部位的肉质特点差异很大，价格也有所不同。因此，本研究旨在评价秦川牛四个不同部位（里脊、外脊、上脑和眼肌）的10个肉质性状，包括总蛋白含量（TPC）、肌内脂肪含量（IMF）、游离脂肪酸 (NEFA)、肉色（L*、a* 和 b*）、剪切力 (SF)、蒸煮损失 (CL)、屠宰后0小时pH（pH0）和屠宰后24小时pH（pH24）。进一步进行转录组和代谢组测序分析，采用加权共表达网络分析（WGCNA）方法探索与性状相关的基因和代谢物模块，构建蛋白-蛋白互作网络（PPI），筛选关键基因和代谢物，以及共同富集的KEGG通路。我们筛选到了3个与肌内脂肪含量（IMF）相关的关键基因（NDUFAB1、NDUFA12和NDUFB7），3个与游离脂肪酸（NEFA）相关的关键基因（CSRP3、ACAA3和ACADVL），1个与肉色相关的关键基因（CREBBP）。本研究为揭示牛不同肌肉部位的差异提供了新的视角，下一步基于本研究筛选到的基因和通路开展深入研究，将有助于改善牛肉品质。

休闲期耕作有利于旱地小麦蓄水增产。然而，目前生长季土壤有机碳（SOC）、全氮（TN）和速效养分对耕作方式的响应尚不清楚。本研究通过5年试验评价了三种耕作方式（NT，免耕；SS，深松；DT，深翻）对土壤物理化学性质的影响，并分析了第5年试验收获期土壤团聚体结构及团聚体碳氮组分。结果表明，与NT相比，SS和DT同时提高了小麦的产量、秸秆生物量和秸秆碳投入。与DT和NT相比，SS通过提高0-40 cm土层SOC_SR和TN_SR来促进有机碳和全氮含量和储量。SS和NT处理下较高的SOC水平与较高的团聚体碳组分正相关，而TN与SON呈正相关。与DT相比，NT和SS处理显著增加0-20 cm土层速效养分

寄生性天敌是生态群落中的关键调节因子，已被广泛应用于害虫生物防治中。草地贪夜蛾，俗称秋粘虫，近年来入侵我国，对农业生产造成巨大的经济损失。中华甲虫蒲螨是近年来新发现的一种外寄生螨，在防控多种重大农业害虫中具有很大潜力。因此，本论文研究中华甲虫蒲螨对寄主草地贪夜蛾的寄生潜能，评价中华甲虫蒲螨亚致死密度对草地贪夜蛾亲代和子代适合度，及其对寄主细胞免疫和体液免疫的影响。结果表明，40头中华甲虫蒲螨能致死5龄草地贪夜蛾幼虫。因多数草地贪夜蛾幼虫能存活至成虫期并交配产出后代，5头和10头中华甲虫蒲螨寄生被认为能对寄主造成亚致死效应。中华甲虫蒲螨亚致死密度寄生能降低草地贪夜蛾蛹重、羽化率和产卵量，并延长其发育历期和寿命。10头和40头中华甲虫蒲螨寄生能破坏草地贪夜蛾的细胞免疫和体液免疫。本研究首次证实寄生螨寄生能对寄主免疫反应产生负面影响。此外，该研究还揭示了寄生螨的生防潜能及其与寄主的相互作用关系。

千粒重是小麦产量的重要组分之一。育种中，粒重位点的叠加可以有效提升小麦的产量潜力。本研究利用W7268×川育12重组自交系群体对千粒重、粒长、粒宽和长宽比进行了QTL分析，共检测到7个主效QTL (QGl.cib-2D, QGw.cib-2D, QGw.cib-3B, QGw.cib-4B.1, QGlw.cib-2D.1, QTgw.cib-2D.1 和 QTgw.cib-3B.1)，解释了2.61-34.85%的表型变异率。其中，两个主效粒重QTL和3个主效粒宽QTL分别存在显著的互作。QTgw.cib-3B.1和QGw.cib-3B共定位于3B染色体，且该位点的千粒重变异主要由粒宽贡献。与其它主效QTL不同，QTgw.cib-3B.1和 QGw.cib-3B对穗粒数没有显著影响。利用所开发的竞争性等位基因特异性PCR (KASP) 标记在高代系中对上述位点进行了验证。通过与前人的结果相比较，发现QTgw.cib-3B.1和 QGw.cib-3B是一个新的控制粒重的QTL位点。在候选区间内，共检测到6种单倍型且其在地方品种与栽培品种分布频率不同。此外，通过基因注释、表达谱分析、同源分析和序列分析，预测了QTgw.cib-3B.1/QGw.cib-3B的候选基因。本研究所报道的主效QTL和开发的KASP标记可为解析粒重的遗传基础和分子标记辅助育种提高小麦产量奠定了基础。

减少氨排放是提高大气环境质量的重要途径之一，农田是全球重要的氨排放来源，合理的农田管理是减少氨排放并获得较高目标产量的基础。本研究基于不同施肥措施的冬小麦-夏玉米轮作长期定位试验，定量氨排放、作物产量和土壤肥力变化，研究全面实施4R养分管理能否显著降低土壤氨排放至较低水平，并研究4R养分管理与有机肥投入的交互作用。结果表明，与传统的高施氮量化肥处理相比，4R养分管理显着降低氨排放量至6 kg N ha^-1 yr^-1（排放因子1.72%），同时维持较高的籽粒产量（12.37 Mg ha^-1 yr^-1）和土壤肥力（土壤有机碳7.58 g kg^-1)。将4R养分管理与有机肥结合，其NH₃排放量（7 kg N ha^-1 yr^-1）和排放因子（1.74%）与4R养分管理相当，同时粮食产量和土壤有机碳分别增加到14.79 Mg ha^-1 yr^-1 和10.09 g kg^-1。与传统的高施氮量化肥处理相比，部分有机肥替代不仅显著减少NH₃排放，而且还提高作物产量和土壤肥力，而秸秆还田对NH₃排放无显著影响。本研究结果强调了通过将4R养分管理与有机肥投入相结合实现碳氮耦合，能够同时实现较高的作物产量和低的环境代价。

Gayal is a rare semi-wild bovine species found in the Indo-China. They can graze grasses, including bamboo leaves, as well as reeds and other plant species, and grow to higher mature live weights than Yunnan Yellow cattle maintained in similar harsh environments. The aim of this study was to identify specific cellulase in the gayal rumen. A metagenomic fosmid library was constructed using genomic DNA isolated from the ruminal contents of four adult gayals. This library contained 38 400 clones with an average insert size of 35.5 kb. The Umcel-1 gene was isolated from this library. Investigation of the cellulase activity of 24 random clones led to the identification of the Umcel-1 gene, which exhibited the most potent cellulase activity. Sequencing the Umcel-1 gene revealed that it contained an open reading frame of 942 base pairs that encoded a product of 313 amino acids. The putative gene Umcel-1 product belonged to the glycosyl hydrolase family 5 and showed the highest homology to the cellulase (GenBank accession no. YP_004310852.1) from Clostridium lentocellum DSM 5427, with 44% identity and 62% similarity. The Umcel-1 gene was heterologously expressed in Escherichia coli BL21, and recombinant Umcel-1 was purified. The activity of purified recombinant Umcel-1 was assessed, and the results revealed that it hydrolyzed carboxymethyl cellulose with optimal activity at pH 5.5 and 45°C. To our knowledge, this study provides the first evidence for a cellulase produced by bacteria in gayal rumen.

Glyphosate has been used worldwide for nearly 40 years, and 30 types of resistant weeds have been reported. Glyphosate is mass-produced and widely used in China, but few studies and reports on glyphosate-resistant weeds and resistance mechanisms exist. Previous studies found a goosegrass species with high glyphosate resistance from orchards in South China and its glyphosate resistant mechanism was described in this study. The cDNA of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS, EC 2.5.1.19), the target enzyme of glyphosate, was cloned from the glyphosate-resistant and -susceptible goosegrass, respectively, and referred as EPSPS-R and EPSPS-S. The Pro106 residue was known to be involved in the glyphosate resistance in most goosegrass populations. However, sequence analysis did not find the mutation at the Pro106 residue in the R biotype EPSPS amino acid sequence. The residue 133 and 382 was mutated in the R biotype EPSPS amino acid sequence instead, but it did not affect the EPSPS-S and EPSPS-R genes sensitivities to glyphosate. RT-PCR and Western blot analyses suggested that EPSPS mRNA and protein are mainly present in the shoot tissues both in the R and S goosegrass biotypes. The EPSPS-R rapidly responds to the glyphosate in R-biotype goosegrass and the induced expression was detected at 12 h post glyphosate treatment. The mRNA and protein expression of EPSPS-R increased constantly as the increasing concentration of glyphosate. However, the expression of the EPSPS-S was not induced significantly by glyphosate in the S goosegrass biotype. Quantification of real-time PCR results showed that the copy number of the EPSPS in R-biotype goosegrass was 4.7 times higher than that in the S goosegrass biotype. All the results implied that EPSPS gene amplification might mainly caused the glyphosate resistance of a goosegrass population collected from orchards in South China.

The rapid detection of glyphosate resistance in goosegrass (Eleusine indica) will enhance our ability to respond to new resistant populations of this major weed. Chlorophyll fluorescence (Fluo) and P700 (reaction center chlorophyll of photosystem I) absorbance were analyzed in one biotype of goosegrass that is resistant to glyphosate and in another that remains sensitive to the herbicide. Both biotypes were treated with a foliar spray of glyphosate. Differences in photosystem II maximum quantum yield (Fv/Fm), effective photochemical quantum yield (Y(II)), and non-photochemical quenching (NPQ) between the biotypes increased over time. Values for Fv/Fm and Y(II) differed between the two biotypes 24 h after treatment (HAT). Differentiated activities and energy dissipation processes of photosystem II (PSII) and energy dissipation processes of photosystem I (PSI) were manifested in the two biotypes 24 HAT with 20 mmol L–1 glyphosate. Differentiated energy dissipation processes of PSI were still apparent 24 HAT with 200 mmol L–1 glyphosate. These results indicate that the Fluo parameters related to PSII activity and energy dissipation and the P700 parameters related to energy dissipation are suitable indicators that enable rapid detection of glyphosate resistance in goosegrass.

Previous studies demonstrated climate change had reduced rice yield in China, but the magnitude of the reduction and the spatial variations of the impact have remained in controversy to date. Based on a gridded daily weather dataset, we found there were obvious changes in temperatures, diurnal temperature range, and radiation during the rice-growing season from 1961 to 2010 in China. These changes resulted in a significant decline of simulated national rice yield (simulated with CERES-Rice), with a magnitude of 11.5%. However, changes in growing-season radiation and diurnal temperature range, not growing-season temperatures, contributed most to the simulated yield reduction, which confirmed previous estimates by empirical studies. Yield responses to changes of the climatic variables varied across different rice production areas. In rice production areas with the mean growing-season temperature at 12-14°C and above 20°C, a 1°C growing-season warming decreased rice yield by roughly 4%. This decrease was partly attributed to increased heat stresses and shorter growth period under the warmer climate. In some rice areas of the southern China and the Yangtze River Basin where the rice growing-season temperature was greater than 20°C, decrease in the growing-season radiation partly interpreted the widespread yield decline of the simulation, suggesting the significant negative contribution of recent global dimming on rice production in China’s main rice areas. Whereas in the northern rice production areas with relatively low growing-season temperature, decrease of the diurnal temperature range was identified as the main climatic contributor for the decline of simulated rice yield, with larger decreasing magnitude under cooler areas.