Ca²⁺离子在维持细胞壁以及细胞膜的完整性中具有重要作用，是植物生长和发育中必不可少的矿质营养元素之一。解析Ca²⁺离子在糖代谢和脂代谢中的作用能够为理解棉花纤维快速伸长阶段细胞膜和细胞壁的动态变化提供有意义的参考。本研究利用胚珠培养系统发现缺Ca²⁺会促进纤维和胚珠细胞的膨大，但同时也会诱导组织的褐化。RNA-seq差异表达基因分析发现缺Ca²⁺使细胞处于一个较高的氧化态，并且激活与糖代谢和脂代谢相关的基因的表达。尤其以糖酵解途径变化最为显著，其代谢途径中的9个酶相关的基因上调表达，缺Ca²⁺处理细胞中的葡萄糖含量显著下降，改变了糖酵解途径的流动。低K⁺能够恢复缺Ca²⁺诱导糖酵解途径相关基因的表达以及葡萄糖的含量。采用电喷雾电离串联质谱技术检测了不同Ca²⁺、K⁺离子处理条件下细胞中脂质组成分的动态变化。缺Ca²⁺处理细胞中自由脂肪酸（FA）、二酰甘油（DAG）和糖脂含量降低，三酰甘油（DAG）磷脂酰乙醇胺（PE）、磷脂酰甘油（PG）、磷脂酰胆碱（PC）含量增加。低K⁺与缺Ca²⁺的互作信号能够恢复FA、磷脂、糖脂含量至正常水平，有效缓解缺Ca²⁺效应。本研究通过在转录和代谢水平的比较分析，揭示了Ca²⁺和K⁺信号互作在维持纤维快速伸长过程中糖酵解和脂代谢中发挥着重要作用。

施肥是提升土壤肥力促进作物增产的有效措施，长期不同施肥对土壤培肥的效果差别很大，依托中国农科院红壤实验站双季稻田连续38年不同施肥定位试验，研究了7种不同施肥处理CK（不施肥）；NPK（化学氮、磷、钾肥料）；M（腐熟牛粪）；NPKM（化学氮、磷、钾和牛粪）；NPM（化学氮、磷和牛粪）；NKM（化学氮、钾和牛粪）；PKM（化学磷、钾和牛粪）对水稻产量、稻田土壤肥力与养分表观平衡的影响。结果表明，各处理水稻年均产量由高到低为NPKM、NPM、NKM、PKM、M、NPK、CK，范围在6214-11562 kg hm²。长期有机无机配施处理（NPKM、NPM、NKM、PKM）较NPK的增产率分别为：22.58%、15.35%、10.53%、4.41%。长期有机无机配施处理（NPKM、NPM、NKM、PKM）的土壤有机碳、全氮、有效氮、速效钾含量均显著高于CK和NPK，其中有机肥配施氮磷肥处理的NPKM、NPM、PKM土壤全磷和有效磷含量显著高于CK、NPK；NPKM处理的水稻年均产量（11562 kg hm²）、有机碳（20.88 g kg^-1）、土壤全氮（2.30 g kg^-1）、全磷（0.95 g kg^-1）、全钾（22.5 g kg^-1）、有效磷含量（38.94 mg kg^-1）均为各处理中最高，NKM处理土壤碱解氮含量（152.4mg kg^-1）和速效钾含量（151.00 mg kg^-1）为各处理最高。氮、磷施用量的增加导致土壤中氮、磷养分出现盈余，但NPKM处理相比其他处理能够有效降低盈余量；各处理土壤中钾素均表现为亏缺。相关性分析表明土壤SOC、TN、AN、TP、AP含量均与水稻产量显著相关（P<0.05），相关系数分别为0.428、0.496、0.518、0.501和0.438。本研究表明，相比单施化肥，长期有机肥配施化肥通过提升土壤肥力，促进土壤养分平衡，显著增加水稻产量，其中有机肥配施氮磷钾肥(NPKM)对于土壤肥力和水稻产量的提升效果最好。

非洲猪瘟（ASF）的持续流行严重威胁全球养猪业的健康发展。该病目前缺乏可应用于临床的疫苗和药物，因此，早期的精准检测对于ASF的有效防控至关重要。p30蛋白在病毒感染早期表达，免疫原性较好且诱导产生抗体水平较高，这些特性使其成为较为理想的非洲猪瘟病毒（ASFV）检测靶点之一。本研究以原核表达的p30蛋白为免疫原，制备了两株可稳定分泌针对ASFV p30蛋白的单克隆抗体（mAb）细胞株，分别命名为4F2和7F3。利用Western blotting和间接免疫荧光实验鉴定两株单克隆抗体均能识别病毒感染。亚型鉴定结果显示，4F2和7F3的重链分别为IgG1和IgG2b，轻链均为κ链。随后，通过原核表达一系列截短p30蛋白鉴定4F2和7F3识别的抗原表位。经5轮截短和Western blotting实验鉴定，最终确定4F2和7F3识别的最短抗原表位分别为¹¹⁸SFETL¹²²和⁷⁶EHQAQEEWNMILHV⁸⁹。在此基础上，进一步分析两个抗原表位在不同毒株p30蛋白序列中的保守性。序列比对结果表明，GenBank数据库中所有p30蛋白序列均包含¹¹⁸SFETL¹²² ，而另一抗原表位⁷⁶EHQAQEEWNMILHV⁸⁹则在非洲以外地区分离的毒株中保守。本研究制备的两株单克隆抗体及鉴定的抗原表位可为检测方法的开发提供材料和基础，同时也可为病毒致病机理和免疫机制等基础研究提供工具。

研究播期和生态点对半冬小麦产量的影响对小麦产量提高具有重要意义。本研究旨在探讨稻-麦轮作条件下播期和生态点对小麦产量以及相关气候资源的影响。试验以两个半冬性小麦品种为材料，分别在东海县和建湖县开展，共设置6个播期。第一播期(S1)基本苗300×10⁴ ha^-1，每推迟一个播期(S2-S6)基本苗分别增加10%。结果表明，播种期的推迟，导致整个生育期天数缩短、有效积温和累计太阳辐射降低。S2~S6产量较S1分别降低了0.22～0.31t ha^-1、0.5～0.78t ha^-1、0.86～0.98t ha^-1、1.14～1.38t ha^-1和1.36～1.59t ha^-1。同一播期，随着生态点北移，生育天数增加，日均温和有效积温降低，累积辐射增加。结果表明，相同播期，东海县的产量比建湖县低0.01 ~ 0.39 t hm ^{- 2}。有效积温、累积辐射与产量呈显著正相关。日均温与产量呈显著负相关。籽粒产量下降的主要原因由于日均温的升高和有效积温的降低导致穗粒数和千粒重下降引起的。

谷类/豆类间作已在世界范围内被广泛采用，以提高可持续农业系统中的作物生产力。在不同的间作组合中，谷子/花生间作可以适应大部分缺水地区。然而，关于谷子/花生间作与单作在不同施氮水平下的产量性状和氮素利用效率差异的研究较少。本研究旨在确定谷子/花生间作的产量优势、经济效益以及适宜的氮肥用量。采用三种种植模式（单作谷子、单作花生和谷子/花生间作）和四种施氮量（0、75、150和225 kg ha^-1）进行了为期两年的大田试验。结果表明，间作系统的土地当量比（LER）和净效应（NE）在施氮量为150 kg ha^-1时达到两年来的最高值（LER两年平均为1.04，NE分别为0.347 Mg ha^-1）。谷子是间作系统中的优势作物（谷子与花生的种间相对竞争能力（Amp）>0，竞争比率（CRmp）>1），单作在施氮量为225 kg ha^-1，间作为150 kg ha^-1时谷子产量最高。不同种植模式的氮利用效率（NUE）两年均在施氮量为150 kg ha^-1时达到最高。间作结合施氮150 kg ha^-1时净收益最高，两年平均为2791 $ ha^-1，效益成本比为1.56。因此，从经济和农业可持续发展的角度来看，150 kg N ha^-1施氮量的谷子/花生间作似乎是替代谷子或花生单作的一个有推广价值的选择。

水稻是中国主要粮食作物之一，世界性三大稻田恶性杂草之一的杂草稻对中国水稻生产的危害时有报道。然而，由于缺乏系统的调查研究，中国杂草稻的总体发生情况和形态类型的分布模式仍不清晰。为了揭示中国杂草稻的发生与危害情况，自2009年至2016年采用七级目测法对中国六个稻作区的999个稻田样点进行了田间调查。结果表明在387个样点中有杂草稻发生，杂草稻整体发生率约为39%。杂草稻综合草害指数在50%以上的样点主要从江苏、黑龙江、宁夏和广东辐射到华东、东北、西北和华南稻作区。通过2017年和2019年的同质园试验对调查过程中采集的287个杂草稻种群的45个形态特征进行了多元分析。结果表明，中国杂草稻存在丰富的形态学变异度和多样性，其形态学特征与原生境的经度、纬度、海拔、气温日较差、气温年较差、生育期的最低温、最高温、降雨量等地理气候因子具有显著的相关性。基于45个形态学性状的聚类分析将287个中国杂草稻种群分为三组：第一组为多分蘖强生长势型杂草稻，籼型，主要分布于江苏；第二组为大叶片型杂草稻，以籼型为主，生长势强，粒型优势弱于第三类杂草稻但强于第一组杂草稻，主要分布在我国的华东、华南、西南地区以及华中南部地区；第三组为大籽粒弱生长势型杂草稻，以粳型为主，主要分布在我国东北、华北、西北等北方地区。三组杂草稻多数无芒且具有黄色颖壳和红色果皮，多个叶型、株型等相关的营养性状以及产量、籽粒形态、穗型相关的生殖性状均存在着显著差异。综上，部分中国稻田已被杂草稻严重侵染，中国杂草稻具有地理、气候和栽培稻类型依赖的形态生物型分化。这暗示了我们需要重视杂草稻对水稻生产的危害，需采取综合防治策略来防控杂草稻。

一步法基因组预测方法广泛应用于畜禽育种中，它可以在一个模型中同时考虑有基因分型和无基因分型的个体信息。目前，基于群体水平的全基因组序列数据快速增长，如何在一步法基因组预测中更好地利用序列数据提高基因组预测准确性备受关注。研究表明，通过整合来自公共数据库的生物学先验信息可提高基因组预测的准确性。因此，本研究中对一步法基因组预测模型进行扩展，以探究如何在模型中有效地整合基因组注释信息提高基因组预测的性能。本研究以黄羽肉鸡群体为实验对象，群体共有1338个个体及23个性状，其中895个个体具有填充的全基因组序列数据，包含5127612个单核苷酸多态性（SNP）标记。研究考虑了不同注释信息与模型的组合，提出四种扩展的一步法模型，并与原始的一步法及基于单倍型的一步法模型进行比较。对于整合基因组注释信息的扩展一步法模型，我们根据鸡的基因组注释信息对SNP标记进行映射，在基因区域和外显子区域分别共映射到3155524和94837个SNP标记。随后采用这些映射到的SNP标记依据不同模型的规则构建基因组亲缘关系矩阵并用于基因组预测。研究结果发现，扩展的一步法模型在其中15个性状中优于其它基准模型。相比于原始的一步法模型，扩展的一步法模型预测能力可提升约2.5%~6.1%。此外，为了进一步提升一步法模型利用序列数据时的基因组预测准确性，我们在该群体中研究了参考群基因分型策略。结果显示在大部分情况下按家系均匀选择的策略来对个体进行基因分型优于随机选择的方式。综上，本研究在一步法框架下，扩展了基因组预测模型，使其整合序列数据以及基因组注释信息。验证了合理利用基因组注释信息和填充的序列数据可提高一步法基因组预测模型的预测能力。而且，在利用序列数据的同时，通过最大化参考群体和候选群体之间的期望亲缘关系来进行基因分型可进一步提高一步法模型的预测能力。本研究的创新在于通过序列数据将基因组注释信息整合至一步法模型中，为在一步法基因组预测方法中有效利用序列数据提供了有益参考。

猪的呼吸道是多种病原微生物的定殖场所，包括常见的四种猪源支原体，分别是猪肺炎支原体（Mhp），猪鼻支原体（Mhr），猪絮状支原体（MF）和猪滑液支原体（MHS）。猪源支原体主要寄居于猪气管黏膜表面，最具代表性的Mhp是引起猪气喘病的主要病原，并易与其他猪呼吸道病原混合或继发感染，引发猪呼吸道疾病综合征，使得感染猪产生慢性持续性呼吸系统疾病，给养猪业带来巨大的经济损失。沿着猪呼吸道上皮细胞的纤毛的黏附是猪源支原体成功感染的前提。猪原代气管上皮细胞（PTEC）是研究包括猪源支原体的各种猪呼吸道病原发病机制的合适模型，但原代PTEC细胞短暂的寿命极大地限制了其应用前景。因此，构建永生化的猪气管上皮细胞，对包括Mhp在内的所有猪源支原体等猪呼吸道病原，具有较高的应用价值。

我们首先提供了详细的分离和培养原代PTEC的方法步骤。随后通过用含有人端粒酶逆转录酶（hTERT）的重组构建的质粒pEGFP-hTERT转染原代PTECs，通过两轮G418的抗性筛选，建立永生化的猪气管上皮细胞系（hTERT-PTECs），并可传代至60代以上。通过比较原代与永生化细胞的上皮细胞表面标志物角蛋白18的表达，细胞周期，细胞生长曲线，端粒酶活性，染色体核型分析，端粒酶基因的蛋白质印记检测，软琼脂和裸鼠成瘤试验，增殖能力等相关基因的定量PCR检测，不仅证实了永生化细胞具备了原代细胞的形态及功能特性，与原代PTECs相比，hTERT-PTEC也具有更长的寿命，更高的端粒酶活性和增殖活性。裸鼠体内未表现出恶性表型，表明该细胞系不具有致瘤性。将不同的猪源支原体菌株感染hTERT-PTECs，通过颜色变化单位CCU₅₀黏附率的定量计算，hTERT-PTECs对所有猪源支原体易感，且原代和永生化细胞之间的黏附能力无显著差异。而对于代表性的Mhp，DNA拷贝定量实时PCR测定，间接免疫荧光测定和蛋白质印迹分析表明hTERT-PTECs能够粘附不同毒力的Mhp菌株。总之，与原代PTECs类似，hTERT-PTECs可以广泛用作猪源支原体的粘附细胞模型，并可用于多种猪呼吸道病原体的感染研究。

地下水资源紧缺是华北平原冬小麦生产面临的一个严峻的挑战，急需先进的节水技术在冬小麦生产上的应用。为了探讨微喷灌技术在冬小麦生产上的节水潜力，我们设置了五个处理，传统畦灌TF1（拔节期和开花期分别灌溉75 mm灌水量）；微喷灌MSI1（拔节期、开花期和灌浆中期分别微喷30 mm灌水量）; 微喷灌MSI2（起身期、拔节期、开花期和灌浆中期分别微喷30 mm灌水量）；微喷灌MSI3（起身期、拔节期、孕穗期、开花期和灌浆中期分别微喷30 mm灌水量）；微喷灌MSI4（返青期、起身期、拔节期、孕穗期、开花期和灌浆中期分别微喷30 mm灌水量），于2012-2015三个生长季通过大田试验进行了研究。研究结果表明，与TFI相比，MSI1和MSI2的水分利用效率分别增加了22.5和16.2%，同时分别降低耗水量17.6和10.8%。在不考虑降雨年型的情况下，与常规畦灌TFI相比，MSI1或MSI能够在降低20-40%灌溉水的前提下保证冬小麦稳产或显著增产。与TFI相比，MSI3的产量和水分利用效率也分别提高了4.6%和11.7%。微喷灌可以实现少量多次的灌溉，降低了土壤的紧实度并有利于小麦根系的下扎，进而有利于关键生育期光合同化物的生产。总之，与TF1相比，MSI1和MSI2能够在降低灌溉用水20-40%的前提下实现稳产或增产，这将为华北平原冬小麦节水高效生产提供一定的技术支撑。

本研究首先使用多性状动物模型对4539头杜洛克猪的达100 kg体重日龄（D100）、达100 kg体重背膘厚（B100）和达100 kg体重眼肌面积（L100）性状进行遗传参数估计。进而，利用高密度SNP芯片对其中的1067头杜洛克猪进行基因分型，并使用基于单标记回归的线性模型对其D100、B100和L100性状进行全基因组关联分析。研究发现该群体的D100、B100和L100性状的遗传力分别为0.300、0.215和0.380。与D100性状相关的SNP位点12个，B100性状相关的SNP位点13个和L100性状相关的SNP位点3个，共注释到13个候选功能基因。这些基因是VPS4B、PHLPP1、ENSSSCG00000034988、CDH20、ENSSSCG00000004911、ENSSSCG00000033637、ADAMTS2、NUDT3、RPS10、TSHZ1、TXN2、GRM4和SNRPC。本研究所定位的D100、B100和L100性状相关的SNP与公共数据库（Animal QTLdb，https://www.animalgenome.org/cgi-bin/QTLdb/index）上相关基因组区域重叠。另外，通过对D100、B100和L100性状相关SNP定位的候选功能基因进行富集分析发现，候选功能基因显著富集在酶的调节或抑制活性和代谢相关的生物学进程（校正P值<0.05）。研究结果进一步揭示了杜洛克猪生长和脂肪性状的遗传结构，将为后续优良品种选育提供依据。

遗传特性的探索，可以了解群体内遗传结构，对探索群体形成提供有效信息。而选择信号检测不仅能反映选择对品种的培育作用，还有助于更好地理解选择机制。海南猪、五指山猪、两广小花猪是我国华南地区优秀的地方品种，具有耐粗饲、性成熟早、肉质鲜美等优点。杜洛克猪经历了长时间的正向选择，具有生长速度快、饲料转换率高、瘦肉率高等特点。本研究基于SNP（single-nucleotide polymorphism）芯片数据，对华南地区地方猪种及杜洛克猪6个群体，共计259个个体进行了主成分分析、系统发生树构建、群体结构分析、连锁不平衡分析、有效群体大小估计以及全基因组选择信号检测，旨在探究华南地区地方猪种的遗传特性与选择信号，为后续保种及利用提供一定参考信息。结果显示，6个猪群体被分为华南地区地方猪种和杜洛克猪两簇，而华南地区地方猪种簇中，海南地区地方猪种与两广小花猪分为两簇，此结果与主成分分析结果相似；5个华南地区地方猪种的有效群体大小在近年呈现迅速衰减趋势；当标记间距为100kb时，5个地方猪群体的连锁不平衡程度变化范围为：0.16-0.20，而杜洛克猪群体的连锁不平衡程度为0.32；此外，在华南地区地方猪种群体基因组中共检测到15个潜在受选择区域，在杜洛克猪基因组中检测到8个潜在受选择区域。综上所述，华南地区地方猪保种工作刻不容缓。群体结果分析和选择信号检测揭示了华南地区地方猪种不同群体间受选择方向的差异。本研究不仅为研究华南地区地方猪种的起源、有效群体大小和选择提供了新见解，并且还为日后该猪种的利用提供了参考信息。

Available irrigation resources are becoming increasingly scarce in the North China Plain (NCP), and nitrogen-use efficiency of crop production is also relatively low. Thus, it is imperative to improve the water-use efficiency (WUE) and nitrogen fertilizer productivity on the NCP. Here, we conducted a two-year field experiment to explore the effects of different irrigation amounts (S60, 60 mm; S90, 90 mm; S120, 120 mm; S150, 150 mm) and nitrogen application rates (150, 195 and 240 kg ha^–1; denoted as N1, N2 and N3, respectively) under micro-sprinkling with water and nitrogen combined on the grain yield (GY), yield components, leaf area index (LAI), flag leaf chlorophyll content, dry matter accumulation (DM), WUE, and nitrogen partial factor productivity (NPFP). The results indicated that the GY and NPFP increased significantly with increasing irrigation amount, but there was no significant difference between S120 and S150; WUE significantly increased first but then decreased with increasing irrigation and S120 achieved the highest WUE. The increase in nitrogen was beneficial to improving the GY and WUE in S60 and S90, while the excessive nitrogen application (N3) significantly reduced the GY and WUE in S120 and S150 compared with those in the N2 treatment. The NPFP significantly decreased with increasing nitrogen rate under the same irrigation treatments. The synchronous increase in spike number (SN) and 1 000-grain weight (TWG) was the main reason for the large increase in GY by micro-sprinkling with increasing irrigation, and the differences in SN and TGW between S120 and S150 were small. Under S60 and S90, the TGW increased with increasing nitrogen application, which enhanced the GY, while N2 achieved the highest TWG in S120 and S150. At the filling stage, the LAI increased with increasing irrigation, and greater amounts of irrigation significantly increased the chlorophyll content in the flag leaf, which was instrumental in increasing DM after anthesis and increasing the TGW. Micro-sprinkling with increased amounts of irrigation or excessive nitrogen application decreased the WUE mainly due to the increase in total water consumption (ET) and the small increase or decrease in GY. Moreover, the increase in irrigation increased the total nitrogen accumulation or contents (TNC) of plants at maturity and reduced the residual nitrate-nitrogen in the soil (SNC), which was conducive to the increase in NPFP, but there was no significant difference in TNC between S120 and S150. Under the same irrigation treatments, an increase in nitrogen application significantly increased the residual SNC and decreased the NPFP. Overall, micro-sprinkling with 120 mm of irrigation and a total nitrogen application of 195 kg ha–1 can lead to increases in GY, WUE and NPFP on the NCP.

Tillage represents an important practice that is used to dynamically regulate soil properties, and affects the grain production process and resource use efficiency of crops. The objectives of this 3-year field study carried out in the Huang-Huai-Hai (HHH) Plain of China were to compare the effects of a new deep vertical rotary tillage (DVRT) with the conventional shallow rotary tillage (CT) on soil properties, winter wheat (Triticum aestivum L.) grain yield and water and nitrogen use efficiency at different productivity levels, and to identify a comprehensive management that optimizes both grain yield and resource use efficiency in the HHH Plain. A split-plot design was adopted in field experiments in the winter wheat growing seasons of 2016–2017 (S1), 2017–2018 (S2) and 2018–2019 (S3), with DVRT (conducted once in June 2016) and CT performed in the main plots. Subplots were treated with one of four targeted productivity level treatments (SH, the super high productivity level; HH, the high productivity and high efficiency productivity level; FP, the farmer productivity level; ISP, the inherent soil productivity level). The results showed that the soil bulk density was reduced and the soil water content at the anthesis stage was increased in all three years, which were due to the significant effects of DVRT. Compared with CT, grain yields, partial factor productivity of nitrogen (PFP_N), and water use efficiency (WUE) under DVRT were increased by 22.0, 14.5 and 19.0%. Path analysis and direct correlation decomposition uncovered that grain yield variation of winter wheat was mostly contributed by the spike numbers per area under different tillage modes. General line model analysis revealed that tillage mode played a significant role on grain yield, PFP_N and WUE not only as a single factor, but also along with other factors (year and productivity level) in interaction manners. In addition, PFP_N and WUE were the highest in HH under DVRT in all three growth seasons. These results provided a theoretical basis and technical support for coordinating the high yield with high resource use efficiency of winter wheat in the resource-restricted region in the HHH Plain of China.

Northeast China (NEC) is one of the major maize production areas in China. Agro-climatic resources have obviously changed, which will seriously affect crop growth and development in this region. It is important to investigate the contribution of climate change adaptation measures to the yield and resource use efficiency to improve our understanding of how we can effectively ensure high yield and high efficiency in the future. In this study, we divided the study area into five accumulated temperature zones (ATZs) based on growing degree days (GDD). Based on the meteorological data, maize data (from agro-meteorological stations) and the validated APSIM-Maize Model, we first investigated the spatial distributions and temporal trends of maize potential yield of actual planted cultivars, and revealed the radiation use efficiency (RUE) and heat resource use efficiency (HUE) from 1981 to 2017. Then according to the potential growing seasons and actual growing seasons, we identified the utilization percentages of radiation (P_R) resource and heat resource (P_H) for each ATZ under potential production from 1981 to 2017. Finally, we quantified the contributions of cultivar changings to yield, P_R and P_H of maize. The results showed that during the past 37 years, the estimated mean potential yield of actual planted cultivars was 13 649 kg ha^–1, ranged from 11 205 to 15 257 kg ha^–1, and increased by 140 kg ha^–1 per decade. For potential production, the mean values of RUE and HUE for the actual planted maize cultivars were 1.22 g MJ^–1 and 8.58 kg (°C d)^–1 ha^–1. RUE showed an increasing tendency, while HUE showed a decreasing tendency. The lengths of the potential growing season and actual growing season were 158 and 123 d, and increased by 2 and 1 d per decade. P_R and P_H under potential production were 82 and 86%, respectively and showed a decreasing tendency during the past 37 years. This indicates that actual planted cultivars failed to make full use of climate resources. However, results from the adaptation assessments indicate that, adoption of cultivars with growing season increased by 2–11 d among ATZs caused increase in yield, P_R and P_H of 0.6–1.7%, 1.1–7.6% and 1.5–8.9%, respectively. Therefore, introduction of cultivars with longer growing season can effectively increase the radiation and heat utilization percentages and potential yield.

Received  19 April, 2017    Accepted  9 May, 2017

© 2018, CAAS. All rights reserved. Published by Elsevier Ltd.
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Granulosa cells (GCs) are somatic cells of ovary, the behaviors of GCs are important for ovarian function.  MicroRNAs (miRNAs) are a class of endogenous 18–24 nucleotide (nt) non-coding RNAs, some of which have been shown to be important regulators of GCs function.  miR-34c involved in the regulation of various biological processes and was identified to be a pro-apoptotic and anti-proliferative factor in many cell types.  However, the roles of miR-34c in GCs function remain unknown.  In this study, we used Annexin V-FITC and EdU assays to demonstrate that miR-34c exerted pro-apoptotic and anti-proliferative effects in porcine GCs.  Dual-luciferase reporter assays, quantitative real-time PCR (qRT-PCR) and Western blotting identified Forkhead box O3a (FoxO3a) as a direct target gene of miR-34c.  The overexpression of FoxO3a rescued the phenotypic change caused by miR-34c in porcine GCs.  In conclusion, miR-34c regulate the function of porcine GCs by targeting FoxO3a.

    Bovine mastitis caused by Staphylococcus aureus is difficult to treat because of increasing resistance against antibiotics, especially penicillin. β-Lactamase and biofilm are responsible for penicillin resistance of S. aureus. The aim of this study was to investigate the β-lactamase activity and biofilm formation capacity of 37 penicillin-resistant S. aureus strains (35 were blaZ positive and 2 were blaZ negative) from bovine mastitis in Gansu Province, China, as well as to measure the intercellular adhesion genes icaA and icaD of these strains. β-Lactamase Test Kit was used to determine the β-lactamase activity, biofilm formation was tested by semi-quantitative adherence assay method. Moreover, the presence of icaA and icaD were measured by PCR. A total of 32 penicillin-resistant S. aureus strains, including the two blaZ-negative strains, were identified as β-lactamase producers. All tested S. aureus isolates produced biofilm in the microtiter plate assay. Meanwhile, all these strains were PCR-positive for the ica locus, icaA and icaD. The study indicated high prevalence of β-lactamase activity, biofilm-forming capacity, and the ica genes among the penicillin-resistant S. aureus isolates, and implied that S. aureus resistant to penicillin was attributed to multiple mechanisms.

A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China.  Based on the sequencing and phylogenetic analysis of 16S rDNA genes, all isolates phylogenetically related closely to Bacillus, Acinetobacter, Stenotrophomonas, Brevundimonas, Arthrobacter, Curtobacterium, Paenibacillus, Plantibacter, Promicromonospora, Serratia, and Microbacterium, among which Bacillus was the predominant genus (47.8% of the total number of endophytic isolates).  These isolates possessed different biological functions.  In 50 endophytic bacteria, 42 isolates produced indole acetic acid (IAA) on King medium.  There were seven isolates showing potency of mineral phosphate solubilization in Pikovaskaia’s (PKO) liquid medium.  Seven isolates exhibited antagonistic effect against Fusarium avenaceum, Colletotrichum coccodes and Phoma foveata.  This was the first report on diversity and plant growth promotion of endophytic bacteria from K. capillifolia on alpine grassland in the Eastern Qilian Mountains, Chain.  It is essential for revealing the relationship among plant, microorganism, and the special environment because the potential function of endophytic bacteria made a contribution to the interactions of plants and endophytic bacteria.

    Pepper (Capsicum spp.) is an important vegetable crop in the world. Now the pepper in China contributes one-third of the world’s peppers production. Genetic diversity of the pepper germplasm of China is expected interesting to know. To explore the structure of genetic diversity in Chinese pepper germplasm resources and possible relationship with cultivar types or geographic origin, we sampled and compared 372 GenBank pepper accessions (local cultivars and landraces) from 31 provinces, autonomous regions and municipalities of China and 31 additional accessions from other countries. These accessions were genotyped using 28 simple sequence repeat (SSR) markers spanning the entire pepper genome. We then investigated the genetic structure of the sampled collection using model-based analysis in STRUCTURE v2.3.4 and examined genetic relationships by the unweighted pair-group method of mathematical averages (UPGMA) in MEGA. In addition to geographic origin, we evaluated eight plant and fruit traits. In total, 363 alleles were amplified using the 28 SSR primers. Gene diversity, polymorphism information content and heterozygosity of the 28 SSR loci were estimated as 0.09–0.92, 0.08–0.92 and 0.01–0.34, respectively. The UPGMA cluster analysis clearly distinguished Capsicum annuum L. from other cultivated pepper species. Population structure analysis of the 368 C. annuum accessions uncovered three genetic groups which also corresponded to distinct cultivar types with respect to the plant and fruit descriptors. The genetic structure was also related to the geographic origin of the landraces. Overall results indicate that genetic diversity of Chinese pepper landraces were structured by migration of genotypes followed by human selection for cultivar types in agreement with consumption modes and adaptation to the highly diversified agro-climatic conditions.

   MicroRNAs (miRNAs) are endogenous 18–24 nucleotide (nt) non-coding RNAs, some of which have been indicated to play key roles in granulosa cells (GCs) function. However, little is known about how the miRNA gene expression itself is regulated in the GCs. Our previous study showed that miR-34c, identified to be a pro-apoptotic and anti-proliferative factor in many cell types, exerted the same effects in porcine GCs. Here, the transcriptional regulation of miR-34c expression in GCs was further investigated. 5´ rapid amplification of cDNA ends (RACE) assay indicated that the pri-miR-34c transcription start site was located in 1 556 bp upstream of pre-miR-34c. With dual-luciferase reporter assay, we confirmed a 69 bp core promoter region (–1 799 bp/–1 730 bp) was indispensable for the transcription of miR-34c. Chromatin immunoprecipitation (ChIP) assay demonstrated that p53, p50, and p65 could bind to the transcription factor binding sites within the 69 bp core promoter region. In addition, deletion of transcripition factor binding sites resulted in obvious change of the miR-34c promoter activity. Finally, using overexpression and knockdown of p53, p50, and p65 strategies, we showed that p53 and p50 could positively regulated miR-34c expression, whereas p65 neletively regulated miR-34c expression in GCs. Our results provide new data about the transcription regulatory mechanism of miRNA genes in GCs.