轮牧被自然科学家认为是保护草地的自然解决方案之一。然而，当牧民采用轮牧时，其对改善草地质量的效果尚不明确。基于中国两个主要牧区的牧户面板数据，本文利用固定效应模型、工具变量法实证分析轮牧对草地质量的影响。结果显示，轮牧在短期内对草地质量的影响不显著，但在长期内具有显著的正向效果。当村庄投资能提高生产效率的公共基础设施或牧民采取轮牧相关的支持措施时，轮牧可以更好地改善草地质量。进一步分析表明，采用轮牧措施的牧民具有更高的放牧强度、更高的补饲强度和更多的圈养牲畜天数，这表明牧民可以在不增加对天然草地压力的情况下更有效地管理牲畜。此外我们还发现，牧业收入和轮牧采用相辅相成，这也是牧户采取轮牧的经济原因。这些研究结果为在发展中国家推广协调生态系统保护和资源利用的基层政策提供了参考。

赤霉病(Fusarium head blight, FHB)是严重影响小麦产量和品质的主要病害之一，在我国长江中下游地区尤为严重。Fhb1和Fhb2是两个主要抗赤霉病位点。扬麦15 (YM 15) 弱筋品质好，是长江中下游地区最受欢迎的品种之一，但对赤霉病抗性较差。本研究采用分子标记辅助选择(MAS)回交策略，利用Fhb1和Fhb2提高扬麦15的赤霉病抗性。每世代进行农艺性状的筛选。我们成功地选择了7个同时携带Fhb1和Fhb2纯合基因型的渐渗系，它们的赤霉病抗性显著高于背景亲本扬麦15。其中3个渐渗系的农艺性状和品质性状与扬麦15相似。本研究表明，利用分子标记聚合Fhb1和Fhb2可显著提高小麦对赤霉病的抗性。

深播是包括玉米在内的作物躲避干旱的一种重要策略，候选基因的克隆是进行玉米耐深播分子机理研究的基础工作。本研究中，我们利用包含386份玉米自交系的关联分析群体对10厘米和20厘米播种深度条件下的四个性状进行鉴定。利用50万SNP标记进行关联分析发现了273个耐深播性状显著关联的SNP。对两组不同的处理进行RNA测序分析分别发现1944和2098个差异基因，其中包含281个共同的差异基因。通过比较273个SNP和281个差异基因的位置发现了7个可能与耐深播相关的候选基因，其中GRMZM2G119769编码一个SNF1激酶互作的蛋白。由于GRMZM2G119769在其他植物中的同源基因跟器官伸长、生长素和光响应有关。同时，候选基因关联分析表明GRMZM2G119769基因的自然变异与玉米的中胚轴长度有关。另外，基因表达分析表明GRMZM2G119769在耐深播材料中表达量高。这些研究结果都支持GRMZM2G119769是玉米耐深播性状的候选基因。本研究不但评价了玉米资源的耐深播特性，还鉴定出一些可能对未来玉米耐深播研究有参考价值的候选基因。

 

该研究系统阐述了长期不同施肥对土壤剖面SOC和N库的影响，通过冗余分析了SOC团聚体组分及影响因素，三维表面分析深入理解剖面SOC和N库对作物产量的影响。与化肥处理相比，长期施用有机肥通过增加表土层 (0–20 cm）SOC输入、SOC储量、TN储量和土壤pH值来提高作物产量。不同施肥处理的SOC团聚体组分存在差异，所有处理SOC团聚体组分高低依次为矿物结合有机碳（mSOC）>粗自由颗粒有机碳（cfPOC）>物理保护有机碳（iPOC）>细自由颗粒有机碳（ffPOC）。施用有机肥处理的所有SOC组分含量均显著高于化肥处理。在不同SOC团聚体组分中，ffPOC对不同施肥处理的敏感性最高。单施有机肥（M）和有机无机肥配施（NPKM）显著提高了表层（0-20 cm）SOC和TN含量，与化肥处理相比，M和NPKM处理降低了深层土壤（80-100 cm）中的SOC和N含量，有利于减少养分垂直流动，从而减少养分的淋溶损失。

二花脸猪、梅山猪和米猪是我国太湖流域优良的地方猪品种，为商品猪的遗传改良做出了巨大贡献。分析这3个猪种的遗传结构和近交水平，对地方猪遗传多样性的保护以及商品猪的持续改良具有重要意义。长纯合片段（Runs of homozygosity，ROH）的长度、数量以及在基因组中的分布模式可以作为评价群体近交水平和物种起源的指标。本研究利用SLAF-seq数据对4个不同品种（二花脸猪、梅山猪、米猪和长白猪）的猪群体进行全基因组ROH 检测，并根据ROH信息计算了各个猪群体的近交系数（F_ROH）。此外，研究还在高频ROH区域筛选与母猪繁殖性状相关的候选基因。在4个猪种的116个个体中共检测到10,568个ROH。PCA分析表明，太湖流域3个猪种的遗传结构与长白猪存在显著差异，而二花脸猪和米猪的遗传结构较为相似。在4个猪群体中，长白猪短ROH（<5 Mb）的频率最高，而梅山猪长ROH（>5 Mb）的频率最高，明显高于二花脸猪和米猪。梅山猪个体ROH覆盖总基因组的长度和ROH总数接近于长白猪，也明显高于二花脸猪和米猪。同时，梅山猪的平均F_ROH最高与长白猪相近，二花脸猪的平均F_ROH最低与米猪相近。以上结果表明梅山猪和长白猪一样表现出较高的近交水平，梅山猪较高的近交水平主要来源于近代的近亲繁殖，而二花脸猪和米猪的近交水平相对较低。此外，大量与母猪繁殖性状相关的候选基因在高频ROH区被鉴定到，这些基因有望作为标记辅助选择(MAS)育种的候选基因。本研究的结果为太湖流域3个猪种的遗传多样性保护、防止近交衰退和遗传改良提供了理论依据。

草地贪夜蛾自2018年12月11日入侵云南后已在我国定殖并形成了周年繁殖区，春夏季将以周年繁殖区为起点向北迁飞。明确其周年发生区域，对指导我国草地贪夜蛾的监测预警及科学防控工作具有重要意义。对冬季草地贪夜蛾在我国热带和亚热带地区的种群动态研究表明，幼虫虫口密度与冬季温度显著正相关，热带地区草地贪夜蛾幼虫种群密度最高，其次为南亚热带地区，而中亚热带北部地区和北亚热带地区未见草地贪夜蛾幼虫发生。研究结果指出草地贪夜蛾在我国1月份等温线10℃以南的热带和南亚热带地区可周年繁殖，该区域包括海南省和台湾省，以及福建、广东、广西、贵州和云南五省的南部区域。该研究明确了草地贪夜蛾的在中国的周年繁殖区域，为该虫区域性监测预警及防控提供了重要依据。

In biological research, chicken embryos are a classic experimental model for the exploration of the embryonic development and cell differentiation.  Transferring exogenous substances into chicken embryos for producing medical antibodies has been widely used in the production practice.  However, there are few studies about the effect of the different injection site and dosage on chicken embryos.  The aim of this study was to explore the effects of different injection sites and dosages on chicken embryo hatching rate and development, so as to provide a basis for further studies using the chicken embryo model.  Freshly laid eggs (Rugao yellow chicken) were injected with different doses of saline at the tip, equatorial plane and the blunt end of the egg shell, respectively.  Egg hatching rate was recorded and compared among injection sites and different doses.  A trypan blue stain was also injected at the aforementioned sites and the growth of chicken embryos was observed.  The SPSS (statistical package for the social science) software was used to analyze the relationship between the chicken eggs hatching rate and the different injection sites or the different dosages.  The experimental results showed that there were significant differences on egg hatching rates among the different injection sites and doses (P<0.05).  The hatchability of the blunt end injection group was significantly higher than that of the other two sites.  The egg hatching rate decreased with increased saline doses.  The egg hatching rate of the 100 µL saline injection group was higher than the 200 and 300 µL dosage groups.  Ultimately, we suggest that the optimal chicken embryo injection process is during early development, at the blunt end site with a dose less than 100 µL to minimize damage to the egg.

    The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage thrips. To assess the incidence of spinosad resistance in F. occidentalis field populations in eastern China, survival rates for 24 different populations were compared with those of a susceptible laboratory strain. All populations showed significantly higher resistance to spinosad compared with the control as determined by comparing median lethal concentrations. Two populations from Shouguang and Liaocheng in Shandong Province were classified as having moderate and high levels of resistance to spinosad with a mean resistance ratio of 17.0 and 89.2, respectively. Our research indicates a widespread reduction in spinosad efficacy for controlling F. occidentalis field populations, and that resistance management strategies should be implemented as soon as practicable, to reduce the potential of progressive resistance development and loss of efficacy.

Spermatogonial stem cells (SSCs) form the foundation for spermatogenesis and sustain male fertility. To explore the regulatory mechanisms of chicken SSCs generation, we obtained highly purified chicken embryonic stem cells (ESCs), primordial germ cells (PGCs) and SSCs by fluorescence-activated cell sorting (FACS). High-throughput analysis methods (RNA-Seq) were used to sequence the transcriptome level of these cells. Gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment were used to analyze RNA-Seq results. BMP4 was used to induce chicken ESCs differentiation to SSCs-like cells in vitro. The quantitative real-time (qRT)-PCR was used to detect the expression changes of the key genes. The results showed that 22 relevant critical pathways were found by RNA-Seq, one of them was the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway. Total of 103 related genes were detected in this pathway. Protein-protein interactions analysis found that 87 proteins were significantly related to 19 key proteins in this pathway. These 87 proteins were enriched in 21 biological processes and 18 signaling pathways. Moreover, during the differentiation of chicken ESCs to SSCs-like cells induced by BMP4 in vitro, JAK2 and STAT3 were activated. The qRT-PCR results showed that the expression trends of JAK2 and STAT3 were basically the same as in vivo. We concluded that JAK/STAT signaling pathway plays an important role in the process of chicken SSCs generation both in vivo and in vitro; it may achieve its function through multiple biological processes and other related pathways.

Upland red soils have been identified as major CO2 and N2O sources induced by human activities such as fertilization. To monitor characteristics of soil surface CO2 and N2O fluxes in cropland ecosystems after continuous fertilizer applications over decades and to separate the respective contributions of root and heterotrophic respiration to the total soil CO2 and N2O fluxes, the measurements of soil surface CO2 and N2O fluxes throughout the maize growing season in 2009 were carried out based on a fertilization experiment (from 1990) through of the maize (Zea mays L.) growing season in red soil in southern China. Five fertilization treatments were chosen from the experiment for study: zero-fertilizer application (CK), nitrogen-phosphorus- potassium (NPK) fertilizer application only, pig manure (M), NPK plus pig manure (NPKM) and NPK with straw (NPKS). Six chambers were installed in each plot. Three of them are in the inter-row soil (NR) and the others are in the soil within the row (R). Each fertilizer treatment received the same amount of N (300 kg ha-1 yr-1). Results showed that cumulative soil CO2 fluxes in NR or R were both following the order: NPKS>M, NPKM>NPK>CK. The contributions of root respiration to soil CO2 fluxes was 40, 44, 50, 47 and 35% in CK, NPK, NPKM, M and NPKS treatments, respectively, with the mean value of 43%. Cumulative soil N2O fluxes in NR or R were both following the order: NPKS, NPKM>M>NPK>CK, and soil N2O fluxes in R were 18, 20 and 30% higher than that in NR in NPKM, M and NPKS treatments, respectively, but with no difference between NR and R in NPK treatment. Furthermore, combine with soil temperature at -5 cm depth and soil moisture (0-20 cm) together could explain 55-70% and 42-59% of soil CO2 and N2O emissions with root interference and 62- 78% and 44-63% of that without root interference, respectively. In addition, soil CO2 and N2O fluxes per unit yield in NPKM (0.55 and 0.10 kg C t-1) and M (0.65 and 0.13 g N t-1) treatments were lower than those in other treatments. Therefore, manure application could be a preferred fertilization strategy in red soils in South China.

High temperature stress (HT) is efficient in breaking endo-dormancy of perennial trees. The effects of HT (50°C) on the respiration of dormant nectarine (Prunus persica var. nectariana cv. Shuguang) vegetative buds were evaluated in the research. We found that bud respiration was transiently inhibited by HT and the pentose phosphate pathway (PPP) and the cytochrome C pathway (CYT) were significantly affected. On the substrate level, PPP was activated in the HT-treated buds compared with the control group. However, the activation did mot occur until hours after HT treatment. The tricarboxylic acid cycle (TCA) in both the HT-treated buds and in the control group proceeded at a low level most of the time compared with total respiration. On the electron transfer level, CYT was transiently inhibited by HT but became significantly active in the later stage. CYT operation in the control group exhibited an attenuation process. The alternative pathway (ALT) fluctuated both in the HT-treated samples and in the control. The results suggest that the temporary CYT inhibition and the following PPP activation may be involved in HT-induced bud dormancy release and budburst mechanisms.

Shuguang (Prunus persica var. nectariana cv. Shuguang) nectarine was used to study effects of photoperiod on keyenzymeactivities of respiration during dormancy induction. The dormancy status was determined with sprouting ability.Spectrophotometry was used to investigate activities of phosphohexose isomerase (PGI), malic dehydrogenase (MDH),and glucose-6-phosphate dehydrogenase (G6PDH). The results revealed that short day (SD) treatment promoted dormancyinduction while long day (LD) treatment postponed the process. During dormancy induction, PGI activities declined,MDH activities changed little, and G6PDH activities increased both in flower buds and leaf buds. PGI activities and MDHactivities in SD treatment were lower than control, and G6PDH activities were higher, which was opposite with LDtreatment. The changes of respiratory key-enzyme activities were adjusted by photoperiod and correlated with thedevelopment of dormancy induction.

Characteristics of dormancy induction and alternative respiration pathway (also known as cyanide-resistant respiration) of nectarine flower buds in different photoperiods were studied to determine the function of photoperiod and alternative respiration pathway in dormancy induction. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of alternative respiration pathway. The results showed that total respiration rate (Vt) in flower buds showed to be double hump-shaped curves. Short day raised, brought the first-hump of Vt forward and delayed the second-hump, while long day delayed the whole curve. The capacity (Valt) and activity (ρValt) of SD and LD changed synchronously and both showed to be double hump-shaped curves. Short day made the first climax of Valt and ρValt existed much earlier, while long day increased their rates significantly. The length of day had little effects on the later period climax. Long day also increased the contributions of alternative respiration pathway in total respiration rate (ρValt/Vt). The changes in alternative respiration pathway were correlated with the induction of dormancy and adjusted by photoperiod. Short day promoted dormancy induction of nectarine trees, while long day delayed it.