AMF促进植物吸收矿质元素的生理机制及对土壤硫素的影响

由于人口不断增长,人们要快速得到高产高质粮食的要求迫切,大量使用化肥,导致了有害物质残留,土壤或水污染,土壤板结或某些营养元素相对匮乏等一系列环境问题。丛枝菌根(Arbuscular mycorrhiza, AM)是土壤内常见的共生结构,由AM真菌(AMF)与土壤根系形成。已有研究表明其可通过分泌代谢物,增大根系与土壤接触面积,调节某些土壤元素存在形式等多种途径,影响植物对土壤元素的吸收转运。硫是维持植物生长发育的必需元素之一,可由于植物对S的需要并不如N,P,K大量,现代农业在对土壤进行施肥过程中往往将其忽略,因此土壤缺S正逐渐成为中国农业发展的限制因素。为了解决以上问题,本文将主要对AMF影响植物吸收土壤元素的途径及生理机制进行总结分析。并根据其作用方式特点进一步分析AM共生对植物吸收转运硫素的影响,指出AMF作为生物化肥的可行性,以期为解决现代化肥的替代问题以及土壤缺硫问题提供新的思路。     

高压雾化设备在现代农业中的应用

高压雾化设备指利用高压雾化主机将经过精密过滤处理的水,输送到造雾专用高压管网,最后到达造雾专用喷头喷出成雾的系统。高压雾化设备在现代农业中主要应用在设施农业降温、加湿、植保以及景观等方面。其中,设施温室降温时依据地域的气候条件、系统投资、后期维护费用、运行费用、降温效果以及对温室湿度的影响等各种因素,来综合考虑高压雾化与其他降温方式联合使用降温,以期达到最佳效果。根据工程项目使用高压雾化设备的经验总结了相关建议,以期为实际生产提供参考。     

Regulatory role of l-proline in fetal pig growth and intestinal epithelial cell proliferation

l-proline (Pro) is a precursor of ornithine, which is converted into polyamines via ornithine decarboxylase (ODC). Polyamines plays a key role in the proliferation of intestinal epithelial cells. The study investigated the effect of Pro on polyamine metabolism and cell proliferation on porcine enterocytes in vivo and in vitro. Twenty-four Huanjiang mini-pigs were randomly assigned into 1 of 3 groups and fed a basal diet that contained 0.77% alanine (Ala, iso-nitrogenous control), 1% Pro or 1% Pro + 0.0167% α-difluoromethylornithine (DFMO) from d 15 to 70 of gestation. The fetal body weight and number of fetuses per litter were determined, and the small and large intestines were obtained on d 70 ± 1.78 of gestation. The in vitro study was performed in intestinal porcine epithelial (IPEC-J2) cells cultured in Dulbecco''s modified Eagle medium-high glucose (DMEM-H) containing 0 μmol/L Pro, 400 μmol/L Pro, or 400 μmol/L Pro + 10 mmol/L DFMO for 4 d. The results showed that maternal dietary supplementation with 1% Pro increased fetal weight; the protein and DNA concentrations of the fetal small intestine; and mRNA levels for potassium voltage-gated channel, shaker-related subfamily, member 1 (Kv1.1) in the fetal small and large intestines (P < 0.05). Supplementing Pro to either gilts or IPEC-J2 cells increased ODC protein abundances and polyamine concentrations in the fetal intestines and IPEC-J2 cells (P < 0.05). In comparison with the Pro group, the combined administration of Pro and DFMO reduced the expression of ODC protein and spermine concentration in the fetal intestine, as well as the concentrations of putrescine, spermidine and spermine in IPEC-J2 cells (P < 0.05). Meanwhile, the percentage of cells in the S-phase and the mRNA levels of proto-oncogenes c-fos and c-myc were increased in response to Pro supplementation, whereas depletion of cellular polyamines with DFMO increased tumor protein p53 (p53) mRNA levels (P < 0.05). Taken together, dietary supplementation with Pro improved fetal pig growth and intestinal epithelial cell proliferation via enhancing polyamine synthesis.     

基于部首嵌入和注意力机制的病虫害命名实体识别

为了解决农业病虫害命名实体识别过程中存在的内在语义信息缺失、局部上下文特征易被忽略和捕获长距离依赖能力不足等问题，以农业病虫害文本为研究对象，提出一种基于部首嵌入和注意力机制的农业病虫害命名实体识别模型(Chinese agricultural diseases and pests named entity recognition with joint radical embedding and self attention, RS-ADP)。首先，该模型将部首嵌入集成到字符嵌入中作为输入，用以丰富语义信息。其中，针对部首嵌入设计了3种特征提取策略，即卷积神经网络(Convolutional neural network, CNN)、双向长短时记忆网络(Bidirectional long short term memory network, BiLSTM) 和CNN-BiLSTM；其次，采用多层不同窗口尺寸的CNNs层提取不同尺度的局部上下文信息；然后，在BiLSTM提取全局序列特征的基础上，采用自注意力机制进一步增强模型提取更长距离依赖的能力；最后，采用条件随机场(Conditional random field, CRF)联合识别实体边界和划分实体类别。在包含11个类别和24715条标注样本的农业病虫害自制语料上进行了实验。结果表明，本文模型RS-ADP在该数据集上精确率、召回率和F1值分别为94.16%、94.47%和94.32%；在具体实体类别上，RS-ADP在作物、病害、虫害等易识别实体上F1值高达95.81%、97.76%和97.23%。同时，RS-ADP在草害、病原等难以识别实体上F1值仍保持86%以上。实验结果表明，本文所提模型能够有效识别农业病虫害命名实体，其识别精度优于其他模型，且具有一定的泛化性。     

Identification of an H1N1 subtype of swine influenza virus and serological analysis

To investigate the epizootic of swine influenza virus(SIV), 60 nasal swabs were collected from a clinical cases of pig farm in Tai'an City, Shandong Province of China in April 2017. SIV was isolated by inoculating into 10-day-old Special Pathogen Free embryonated eggs and the whole genome was sequenced. An H1N1 subtype SIV was isolated and designated as A/swine/Shandong/TA04/2017(H1N1). Phylogenetic analysis showed that apart from the polymerase A(PA) fragment belonging to the 2009 pandemic H1N1 branch, seven genome segments belonged to avian-like H1N1 influenza virus lineage. The cleavage site sequence of the hemagglutinin(HA) protein was PSIQSR↓G, which is a typical molecular biological characteristic. Five potential N-glycosylation sites(N14, N26, N277, N484 and N543) were found in the HA gene. To further investigate the epidemiology of SIV in this farm, the 995 serum samples were assessed with EAH1N1 2009 pandemic H1N1 and H3 N2 antigens. The results showed that the total positive rate was 65.43%. The positive rates of single virus infection detected by EAH1N1, 2009 pdmH1N1 and H3 N2 for serum HI(Hemagglutination inhibition) were 48.35, 30.85 and 7.47%, respectively. The results showed that SIV in Shandong Province has been reassorted in some segments and the SIV-positive rate was high on the SIV outbreak farm. These data provide evidence of an epizootic of SIV.     

生物炭对酸化茶园土壤性状和真菌群落结构的影响

为探讨生物炭长期施用对酸化茶园土壤改良和真菌群落结构的影响,分析了按生物炭用量0、2.5、5、10、20、40 t·hm^-2施用5年后的茶园土壤性状和真菌群落结构变化。结果表明,施用生物炭5年后的茶园土壤pH提高了0.16~1.11,可溶性有机碳含量提高了52.6%~92.3%,而铵态氮和硝态氮含量以10 t·hm^-2处理最高。施用生物炭5年后的土壤性质变化,进一步影响了真菌群落结构,表现为Chao指数、ACE指数和Shannon指数随生物炭用量增加呈先增加后降低的趋势;提高生物炭施用量对茶园土壤次要作用的真菌（LDA值<3.50）丰度的增加效果高于优势真菌（LDA值>3.50）的效果,其中被孢霉属、木霉属、毛壳菌属的相对丰度增加,黑盘孢属的相对丰度降低。     

农艺措施对谷子产量及抗倒伏力学性能的影响

【目的】明晰栽培条件互作对谷子叶片光合特性、茎秆生物力学性质指标的耦合影响,为运用谷子茎秆生物力学性质进行抗倒伏特性评价,为优化谷子种植栽培条件及抗倒伏优种筛选提供合理农艺措施和理论支持。【方法】采用裂区试验设计方法,主区选取4个在生产中具有代表性的谷子品种,副区为基于不同的播种密度与施肥量、播种密度与水分、水分与施肥量互作处理栽培条件,系统研究了栽培措施对谷子生长发育以及茎秆抗倒伏生物力学性质的影响。【结果】（1）除水分对谷子茎秆节平均直径影响不显著外,谷子品种、施肥量、播种密度及水分4个因素对谷子的产量、光合生理特性及茎秆形态特性均有极显著影响（P＜0.001）;（2）谷子的千粒重、产量均随施肥量和水分的增加而增加;随播种密度的增加,千粒重呈下降趋势,产量呈现先上升后下降趋势;谷子旗叶SPAD值及最大荧光值（Fm）开花期显著高于灌浆期,开花期旗叶SPAD值、灌浆期旗叶Fm可作为谷子育种的目标性状;（3）播种密度对谷子田间倒伏率的影响最大,其次是水分、品种,施肥量的影响最小;（4）谷子茎秆倒数第二节的抗拉倒力与株高、节平均长度及茎秆节含水率显著负相关,与节平均直径显著正相关。【结论】不同农艺措施互作栽培条件下,单因子对谷子的产量、植株光合生理特性及茎秆力学性能影响最大;选择优良品种、合理密植（≤70万株/hm²）、适当水肥是提升谷子籽粒品质、增加产量、减少田间倒伏率的有效措施。     

多孢木霉HZ-31菌株侵染对野燕麦生理机制的影响

选用青海农田常见杂草野燕麦作为靶标杂草,盆栽接种后测定了多孢木霉HZ-31菌株对野燕麦体内各种生理指标的影响,分析了寄主与病原菌相互作用的生理变化机制。结果表明,多孢木霉HZ-31菌株侵染野燕麦后,对植株生理机制防御酶的影响是多方面的,PAL和POD活性增加,以抵御菌株侵染,其余生理防御指标包括MDA含量、CAT、PPO、SOD活性、可溶性蛋白含量和叶绿素含量则受到菌株侵染的破坏,含量减少、活性降低。被抑制的防御酶作用效应大于被促进的防御酶。HZ-31菌株的侵染钝化或抑制了野燕麦体内主要酶类,中断相应的酶促反应,引起植物广泛的代谢变化,包括细胞膜透性改变、干扰光合作用、蛋白质合成、酚类物质代谢等生理方面的变化。     

国审‘陇育5号’小麦丰产广适特性分析与推广应用策略

分析国审 ‘陇育5号’小麦丰产性、抗逆性、广适机理及推广策略,以期为北部旱地小麦高效育种和品种推广提供借鉴。利用多年多点国家北部旱地、甘肃省陇东片区域试验及高产示范资料,对冬小麦新品种‘陇育5号’的性状进行比较分析。‘陇育5号’多点区域试验、生产试验产量平均为4922.54 kg/hm²,比对照品种平均增产13.28%,增产点（次）率89.97%。有效穗数597.0万/hm²,收获指数39.6%,旱地产量潜力达6399.0 kg/hm²。成穗多与收获指数较高是实现‘陇育5号’高产潜力的基础,抗寒抗旱抗病、耐生育后期高温、粒重变异小是其广适性和大面积推广的重要保障。‘陇育5号’丰产性强,抗寒抗旱、综合抗逆性好,品质优良,适应范围广。在推广应用中,应采取项目推广方式,订单式原种生产,合同式良种繁育,“科研单位+地方政府+种业企业+示范农户”四位一体的推广模式。     

400克/升氯氟醚菌唑悬浮剂对香蕉叶斑病的防治效果

通过大田试验研究了400克/升氯氟醚菌唑悬浮剂防治香蕉叶斑病效果及其对香蕉产量的影响。研究结果表明,分别以20毫升、13.3毫升、10毫升400克/升氯氟醚菌唑悬浮剂兑水60公斤分3次喷雾施药,第二次施药后14d后对香蕉叶斑病防治效果在60.43-66.52%,第三次施药后14d后对香蕉叶斑病防治效果在75.72-80.72%,并对香蕉的单株产量有明显增产效果。其中尤以20毫升400克/升氯氟醚菌唑悬浮剂兑水60公斤剂量喷雾处理的效果最好。