在中国东北稻区，肥料氮去向与施氮量间的关系以及残留氮的去向目前仍不清晰。为此本研究田间小区和¹⁵N微区试验，分别设置0、75、105、135和165 kg N/hm²五个施氮水平，对应处理为N0、N75、N105、N135和N165。微区试验在2017年施用¹⁵N标记尿素，2018年施用等量的普通尿素。分析了氨挥发、淋洗、地表径流、水稻产量以及植物和土壤中氮含量和¹⁵N丰度变化情况。结果表明，水稻产量与氮肥施用量呈线性平台关系，最佳施氮量为135 kg N/hm²；水稻氮吸收量随着氮量的增加而增加，差减法氮肥吸收利用率（RE_N）在2017年和2018年平均分别为45.23%和56.98%。2017年施氮量为135 kg N hm²时RE_N最高，2018年RE_N受施氮量影响不大，而氮量超过135 kg N hm²时氮肥农学利用率（AE_N）和氮肥生理利用率（PE_N）显著降低。在中国东北稻区肥料氮氨挥发、淋洗和径流的损失较少。2017年和2018年氨挥发量分别占总施氮量的0.81%和2.99%，氮通过淋洗和径流的损失比例分别为4.45%和不到1.05%，东北稻区表观反硝化损率失约为42.63%。2017年0-40cm土层中残留氮量为18.37-31.81 kg/hm²，残留率为19.28-24.50%。土壤中¹⁵N肥料的残留量随施氮量增加而增加，残留氮主要集中在0-10cm土层中，占总残留氮的58.45-83.54%，并随深度增加而减少，但0-10cm土层残留氮占0-40cm土层残留氮的比例却随施氮量增加而减少。平均约有5.4%的残留氮在下一季被水稻吸收利用，50.2%流失，44.4%继续残留在土壤中，因此在计算施氮量时应考虑残留氮的数量。考虑到水稻产量与氮效率的平衡，本试验中东北稻区适宜施氮量为105-135 kg N/hm²。

研究表明氮肥深施能够减少稻田中氮素淋失、提高氮肥利用率；然而，我们对于稻田土壤微生物，特别是微生物中的丰富物种和稀有物种对于氮肥深施的响应知之甚少，而这一过程对于我们理解农业生态系统的生物多样性和功能至关重要。在本研究中，我们利用二代测序技术和生态模型理论，研究了不同氮肥施用条件下水稻根际土壤中丰富和稀有类群在水稻生长4个阶段的多样性模式及其组装机制。结果显示，在水稻根际土壤中丰富物种和稀有物种具有不同的分布模式：丰富物种广泛存在于各样品中，而稀有物种不是普遍存在的。随机过程在丰富菌群和稀有菌群的群落构建过程中均起着主导作用，其中扩散限制在丰富菌群中起着更重要的作用，而漂移等非主导过程在稀有菌群中起着更重要的作用。扩散限制对氮肥深施下丰富物种和稀有物种的影响高于不施氮肥和传统撒施；然而均值扩散对不施氮肥和传统撒施下稀有物种的影响高于氮肥深施处理。网络分析表明，与稀有物种相比，丰富物种相互之间连接紧密且占据网络的中心位置。尽管如此，大部分的关键物种由稀有物种组成，它们可能在维系网络稳定过程中发挥重要作用。总之，我们的研究结果突出了氮肥深施下根际土壤中丰富菌群和稀有菌群生态机制和共发生模式。

土壤干旱和盐胁迫是植物生长和农业生产力的主要限制因素。主胚根是感知干旱和盐分胁迫信号的第一个器官。研究发现，与对照植株相比，遭受干旱、高盐和复合胁迫的玉米植株的主胚根长度明显变短。利用气相色谱-质谱联用技术测定了玉米主胚根在干旱、高盐和复合胁迫下代谢产物的变化。本研究共测定86种代谢产物，包括29种氨基酸和胺，21种有机酸，4种脂肪酸，6种磷酸，10种多糖，10种多元醇和6种其他代谢物。其中，53个代谢物在不同胁迫下均有显著变化，且大部分代谢物含量呈下降趋势。共计4种和18种代谢物分别对三种处理均有显著的上调和下调。糖和多元醇等可溶性物质的含量增加以维持渗透平衡。TCA循环中柠檬酸、酮戊二酸、延胡索酸、苹果酸的水平显著降低，莽草酸途径中奎宁酸、莽草酸等代谢物含量显著降低。本研究揭示了主胚根在干旱和盐胁迫复合作用下的复杂代谢反应，拓展了我们对玉米根系对非生物耐受性反应机制的理解。

The wild hawthorn species, Crataegus songorica K. Koch., is an important wild germplasm resource in Xinjiang, China that has been endangered in recent years.  The genetic diversity of C. songorica K. Koch. germplasm in five populations from Daxigou, Xinjiang, China were evaluated based on phenotypic traits and ISSR molecular markers to provide basic information on resource protection, rational utilization and genetic improvement.  The F-value for the phenotypic differentiation coefficient of the 33 traits measured ranged from 0.266 to 15.128, and mean value was 13.85%.  The variation among populations was found to be lower than that within population.  A total of 303 loci were detected within the five populations by 12 primers.  Within 298 polymorphic loci, the polymorphism was 98.35%, showing a high genetic diversity in C. songorica K. Koch.  The gene diversity within population, total population genetic diversity, genetic differentiation coefficient and gene flow were 0.2779, 0.3235, 0.1408, and 3.0511, respectively.  Our results showed that C. songorica K. Koch. from Xinjiang has a high level of genetic diversity at both the phenotypic and molecular levels.  Significant genetic differentiation existed within population and the differentiation trend showed a regional association.  And in this study, in situ and ex situ conservation approaches were raised for wild hawthorn protection utilization.

  The safety of feeding transgenic cry1Ab/cry1Ac rice (a genetically modified (GM) rice variety) to broilers was examined from an immunological perspective. Hatchling Arbor Acres chickens (240) were assigned to two dietary treatments (diets containing GM or non-GM rice) with 12 replicates per group and 10 birds per replicate. Traits were measured on one randomly selected bird from each replicate at d 21 and 42. The 42-d feeding trial revealed that cry1Ab/cry1Ac rice had no significant effect relative to non-GM rice on body weight and the immune organ indices. No significant pathological lesion in the spleen and bursa of Fabricius was found in the GM rice group. There were no significant differences in serum concentrations of immunoglobulin Y (IgY), IgM, interleukin 4 (IL-4) and IL-6 between the two groups at d 21 or 42, except for IL-6 being higher (P<0.05) in the GM-fed chickens at d 42. There were no differences in the T and B lymphocyte transformation rate and CD4+/CD8+ ratio between the two groups at d 42. Additionally, there was no significant difference between the two diets in expression of relevant genes viz. the major histocompatibility complex class II beta chain (BLB2), interferon beta 1 (IFNβ), tumour necrosis factor alpha-like (TNFα) and toll-like receptor 4 (TLR4) in the spleen and bursa of Fabricius. All the data demonstrated that transgenic cry1Ab/cry1Ac rice had no adverse effect on these aspects of immune function of broilers during 42-d feeding trial. Transgenic rice was therefore indistinguishable from non-GM rice in terms of short-term feeding in chickens.  

The study was conducted in Zhifanggou Watershed, Shaanxi Province, China, to evaluate the effect of different vegetation types on hot-water extractable C, N and P fractions, with the aim to determine whether hot-water extractable fractions could be used as indicators of soil quality change in Loess Plateau. The six vegetation types established in 1975 were (i) Robinia pseudoacacia L., (ii) Caragana korshinkii Kom., (iii) Pinus tabulaeformis Carr., (iv) P. tabulaeformis-Amorpha fruticosa L., (v) R. pseudoacacia-A. fruticosa, and (vi) grassland. A cropped hillslope plot and a Platycladus orientalis L. native forest plot were used as references. The results indicated that the conversion of native forest to cropland resulted in a significant decline in the hot-water extractable C, N and P fractions. Hot-water extractable C, N, and P increased when cultivated land was revegetated, but after 30 years the amount of hot-water extractable C, N, and P in revegetated fields was still much lower compared to native forest. Hot-water extractable fractions increased more under mixed-forest than under pure-forest stands. Furthermore, there was a significant correlation between the hot-water extractable fractions and soil chemical and microbiological properties. The results showed that hot-water extractable fractions could be used as indicators of soil quality change on the Loess Plateau.