本试验探讨了7种不同类型缓控释肥一次性施用对水稻产量及群体特征的影响。在研究肥料氮素（N）释放特征的基础上，于2018和2019年进行盆栽试验，以常规分次施肥（CK，基穗比为1:1）为对照，对水稻叶片SPAD值、产量及其构成、茎蘖动态和干物质积累进行研究。结果表明：不同类型缓控释肥的氮素释放特征差异显著。树脂包衣尿素（PCU）表现为控释模式，整个生育期持续释放氮素；硫包衣尿素（SCU）表现为缓释模式，中后期氮素释放不足；脲酶抑制剂尿素（AHA）和脲甲醛（UF）表现为速释模式，前期爆发性释放，中后期无释放，但其供肥能力可持续到抽穗期。PCU延缓了高峰苗期，与CK相比，干物质积累、叶片SPAD值无显著差异，同时由于整个生育阶段氮素的持续释放，每穗粒数、结实率和千粒重增加，从而提高水稻产量；SCU由于后期氮供应不足，总颖花量低，水稻产量降低，但差异不显著；AHA和UF易受环境因素的影响，对产量的影响不一致。本试验结果表明，在盆栽等量施氮条件下，供肥能力强、有效持续时间长的肥料类型更有利于水稻后期干物质积累，提高产量。

为探究机插条件下不同水稻品种倒伏差异的主要因素及其对氮肥的响应，2017年和2018年在江苏丹阳（长江中下游代表性区域）开展了两年重复的田间试验，以22个杂交籼稻、22个常规粳稻以及2个籼粳杂交稻3种类型水稻为材料，设置3个氮肥水平(0、150、300 kg ha^-1)，采用毯苗机插的移栽方式，从倒伏相关的力学指标、形态学指标以及物质转运等方面进行系统研究。不同类型水稻产量的差异表现为常规粳稻<杂交籼稻<籼粳杂交稻。杂交稻（杂交籼稻、籼粳杂交稻）的倒伏指数(LI)高于常规粳稻源于其较高的株高，籼粳杂交稻较低的茎鞘物质表观输出率导致其LI显著低于杂交籼稻。杂交籼稻品种间倒伏指数较大的差异主要来源于茎鞘物质表观输出率，株型紧凑的品种茎鞘物质表观输出率低，因而具有较强的抗倒伏能力；常规粳稻品种间的差异则是由断面模数(Z)即茎粗造成的。籼粳杂交稻或常规粳稻的倒伏指数在氮肥处理间的变异相对较小，高氮水平下均没有发生倒伏，这是由于其叶倾角较小且在高氮条件下变化不大；而杂交籼稻不同品种LI和倒伏率对氮肥的响应存在较大的差异，株型紧凑的品种耐高氮。因而，紧凑株型品种适宜作为机插条件下的抗倒耐氮型品种。

To identity the potential pathogen associated with the yellow vein clearing symptom on lemon trees, the profiles of virus-derived small interfering RNAs from citrus samples were obtained and analyzed by deep sequencing method in this study.  Twenty-seven contigs almost cover the full length genome of Citrus yellow vein clearing virus (CYVCV) isolate YN were obtained using the small RNA deep sequencing technology.  Analysis showed that this isolate CQ shared the highest nucleotide identity with isolate Y1 (JX040635) and YN (KP313242), both of which belong to the genus Mandarivirus in the family Alphaflexiviridae.  Mapping analysis of viral-derived siRNA (vsiRNA) profiles revealed an uneven distribution pattern of their generations along both positive and negative genome strands, and 22- and 21-nt vsiRNAs ranked the majority.  BLAST against viroids and other viral databases confirmed that this sample was single-infected only by CYVCV, which indicated that CYVCV was the exact causal agent for the yellow clearing symptom occurring on lemon.  This is the first CYVCV isolate detected in Chongqing and the second in China.  This result could provide a molecular basis for the investigation of citrus viral diseases to protect citrus health in this region. 

This paper primarily analyzes the evolution path of China’s pork price by employing the threshold autoregression model (TAR). Considering the unit root test with a threshold effect and heteroskedasticity of the TAR model, we show that the pork price series is a unit root process in each regime, and the heteroskedasticity in the TAR model greatly affects the results of linearity test. We find that the changing process of pork price has two regimes: mild regime and expansion regime. In particular, a change belongs to an expansion regime if it is larger than 0.5881; otherwise, it falls in the mild regime.

Understanding the relationship between the timing of N fertilizer applications and crop primary production is crucial for achieving high yield and N use efficiency in agriculture. This study investigated the effects of starting-N plus topdressing N applications (as compared to the common practice of all basal application) on soybean photosynthetic capacity under different planting densities. A field experiment was conducted in two growing seasons (2011 and 2012), and the soybean (Glycine max L. Merrill) cultivar was Dongnong 52, three planting densities (20, 25 and 30 plants m-2), and four N fertilizer application patterns (all N fertilizer of 6 g N m-2 as basal fertilizer, all N fertilizer as topdressing at beginning pod stage (R3), 1.8 g N m-2 as basal fertilizer and 4.2 g N m-2 as topdressing at stage R3 and full pod stage (R4), respectively). The results indicated that under the same planting density, compared to applying all N as basal fertilizer, the application of starter-N plus topdressing N substantially reduced the rate of pod abscission, and enhanced leaf area index (LAI) significantly at beginning seed stage (R5) (P<0.05), net assimilation rate (NAR) during stages R4-full seed stage (R6) (P<0.05), contribution rate of post-seed filling assimilate to seed (CPA) (P<0.05), and yield (P<0.05). Applying topdressing N at stage R4 resulted in higher net primary production and yield than applying topdressing N at stage R3. When applying starter-N plus topdressing N at planting density of 25 plants m-2, LAI after stage R5 and NAR after stage R4 were increased by 5.92-16.3% (P<0.05) and 13.7-26.6% (P<0.05) with the planting density of 20 plants m-2, respectively, and yield was 8.46-14.0% (P<0.05) higher than that under 20 plants m-2. When planting density increased to 30 plants m-2, only LAI during stages R4-R5 and NAR during stages R4-R5 increased by applying starter-N plus topdressing N, while the other indexes declined. Overall, results of this study demonstrated that applying starter-N plus topdressing N could significantly enhance soybean photosynthetic capacity after stage R5 at planting density of 25 plants m-2.

Soybean is a major cash crop in the world, and its oil content was one of the very important traits. Therefore, the study of gene mapping for oil content in soybean is very important for breeding application. At present, at least 130 QTL loci for soybean oil content have been published; however, the mapping results of oil content were dispersed and a coalescent public map should be established to integrate the published QTLs, and to more efficiently mine genes based on the metaanalysis method of the bioinformatics tools. This study was to construct an integrated map of QTLs for soybean oil content and accelerate the application of bioinformation resource related to oil content improvement in the practice of soybean breeding. We collected information of 130 QTLs reported over the past 20 yr for soybean oil content and used the Software BioMercator 2.1 to project QTLs from their own maps onto a reference map, which was an early-integrated map constructed by Song (2004) for oil-content quantitative trait loci (QTLs) in soybean. Gene mining was performed based on the meta-analysis by running the local ver. GENSCAN and InterProScan. The confidence interval of QTLs was efficaciously narrowed using the meta-analysis method, and 25 consensus QTLs were mapped on the reference map. Using a local version of GENSCAN, 12 805 sequences in the consensus QTL intervals were predicted. With BLAST, these predicted sequences were aligned to gene sequences from the International Protein Index database using InterProScan locally. Thirteen predicted genes were in the class of the geme ontology (GO) accession (0006631), which were involved in the fatty acid metabolic process. These genes were analyzed using BLAST at the NCBI website to examine whether they were related to oil content. Six genes were found in the oil-synthesis pathway. Twenty-five consensus QTLs and six genes were found in the oil-synthesis pathway. These results would lay the foundation for marker-assisted selection and mapping QTL precisely, and these genes will facilitate the researches on the gene mining of oil synthesis and molecular breeding in soybean.