种植密度对陕单609产量及主要性状的影响

玉米是陕西省旬邑县的主要粮食作物,为探索玉米新品种陕单609在渭北旱塬春玉米区的最佳种植密度,充分挖掘该品种的增产潜力,2011~2013年该县连续3年设计5种不同种植密度进行试验研究。结果表明:陕单609种植密度从4 000株/667m2增加到5 000株/667m2,随着密度的增加玉米产量逐渐提高,种植密度为5 000株/667m2时产量最高,为955.3kg/667m2,之后随着密度增加,产量逐渐降低;植株主要农艺性状随着密度的增加,株高和穗位升高,茎粗明显变细,双穗率下降,倒伏率增大,穗长、穗粗、穗行数、行粒数和千粒重均呈减少趋势。得出该地陕单609旱作地膜栽培的适宜密度应为4 500~5 000株/667m2。     

玉米定向栽培密度与施肥量试验研究

采取裂区设计法,研究玉米定向栽培条件下,半紧凑型玉米太平洋98的种植密度与施肥量对产量的影响。结果表明,不同密度、施肥量间及其交互作用的产量差异达极显著水平。当施肥量为每667 m2纯氮少于25 kg时,产量随密度增加而增加,用量达30 kg时,产量下降,但下降不显著;当施肥量在较低密度(每667 m23 500株)时,产量随施肥量增加而增加,但在密度较高(每667 m24 000株以上)且纯氮用量增至30 kg时,产量开始下降,但下降也不显著。处理A2B3(每667 m24 000株、纯氮25 kg)所得产量最高,每667 m2产量为628.6 kg。     

不同种植密度对玉米新品种汉玉9号产量的影响

为明确玉米新品种汉玉9号在陕南秦巴山区的高产最适宜种植密度,以汉玉9号为材料,在相同施肥力水平条件下,设置不同种植密度,探讨种植密度对汉玉9号的主要产量构成因素及籽粒产量的影响,确定汉玉9号的高产最适种植密度,为陕南秦巴山区玉米生产提供高产理论。结果表明:不同种植密度处理对汉玉9号产量影响由高到低顺序为:4 000株·667 m~(-2)4 500株·667 m~(-2)3 500株·667 m~(-2)5 000株·667 m~(-2)3 000株·667 m~(-2)。玉米新品种汉玉9号的产量随种植密度的增加呈现先增加再降低的趋势,最高产量种植密度为:4 000株·667 m~(-2),最大密度处理(5 000株·667 m~(-2))的产量与最小密度处理(3 000株·667 m~(-2))的产量结果比较表现为增加产量,表明汉玉9号增加种植密度有增加增产量的潜力,4 000株·667 m~(-2)~4 500株·667 m~(-2)密度范围为汉玉9号在陕南秦巴地区高产最适种植密度。     

辽西半干旱区密植型玉米品种不同密度对生育和产量的影响

选用密植型玉米辽单565和郑单958两个新品种,每667m2种植5 000株、4 500株、4 000株,以当地主栽品种丹玉39每667m2种植3 200株为对照,进行了密度比较试验.结果表明,密植品种增加密度后都比对照品种产量高.郑单958每667m2种植5 000株、4 500株、4 000株的分别比对照品种丹玉39增加36.15%、22.82%、20.06%;辽单565每667m2种植5 000株、4 500株的分别比对照品种丹玉39增加19.2%、15.15%.     

正大12号玉米在宁夏灌区的适宜密度及产量潜力的探析

试验在大田栽培管理条件下采用6种种植密度对正大12号玉米品种的最大产量潜力及适宜种植密度进行研究。试验结果表明：正大12号种植密度在4000~5500株／667m2之间均能达到1100—1130kg／667m2的产量水平，其中在4500株／667m2产量最高，为1134．06kg／667m2。统计分析表明：穗数、千粒重、穗粒数与产量的关系十分密切，不同因子对产量提高的贡献大小分别为穗数〉穗粒数〉千粒重。     

种植密度对陕北风沙滩区春玉米产量影响研究

为确定陕北风沙草滩区玉米种植的最佳密度,通过设置667 m 4 000、5 000、 {6 000 }、7 000、8 000和9 000株6个密度梯度,主要研究不同的种植密度,对陕北风沙滩区春玉米的农艺性状、产量以及产量构成因素的影响。结果表明,株高、穗位高、秃尖长随种植密度的增加,呈增加趋势;产量随种植密度的增加,表现出先上升后降低的趋势;密度在 {8 000 }株·667m^-2,供试品种可获得高产,产量1 148.96 kg·667m^-2,较其他处理分别增产31.3%、16.6%、8.4%、4.8%和5.7%。     

夏播紧凑型玉米黔单10号高产栽培技术研究

对国家审定的紧凑型玉米黔单10号,在每穴施等量基肥的条件下,于2000～2001年进行了栽培密度、追氮量试验.结果表明,夏播黔单10号的产量随密度和追N量(尿素)的增加而提高,反之则低.经方差分析结果表明,处理间、密度间、肥料间、年份间、密度×年份的产量差异均达1%极显著水平.每667m2最佳密度3 500～4 000株和追N量(尿素)40 kg,平均产量为810.64～910.83 kg/667m2,较3 000株/667m2和追氮量20 kg/667m2(CK)的增产18.59%～19.9%.     

玉米辽单565、KWS3376种植密度对产量的影响

为鉴定辽单565、KWS3376这2个玉米品种的丰产性,在塔城地区设置了供试玉米不同种植密度对产量的影响试验。试验结果表明:辽单565在每667米~2种植密度6 000株时,667米~2产量最高,为1 100.6千克;KWS3376在667米~2种植密度7 000株时,667米~2产量最高,为1 211.7千克。     

冬种马铃薯不同种植密度的产量效应研究

进行马铃薯不同种植密度的试验研究,结果表明:每667 m2种植5 500株的产量最高,达2 291.2 kg。马铃薯产量与种植密度呈极显著的抛物线型关系,生产上以每667 m2种植5 000株为宜。     

不同种植模式和密度对夏玉米郑单958产量的影响

玉米是重要的粮食作物和饲料作物,郑单958在陕西关中地区夏玉米生产中占据主导地位,2012年陕西省宝鸡市陈仓区通过进行等行距(60 cm+60 cm)和宽窄行(50 cm+70 cm)两种不同种植模式下每667m23 000株、4 000株、5 000株、6 000株、7 000株5个密度梯度田间试验,结果表明:郑单958宽窄行种植模式显著优于等行距种植模式,在一定的密度范围内,产量随着密度的增加而提高。以宽窄行种植模式、密度6 000株·667 m-2组合最优,产量构成三因素最为协调,单位产量最高。     

Web2.0,以个人为中心的互联网时代的到来

本文介绍了Web2．0的知识和背景，对Web2．0出现的基础以及典型技术和应用作了阐述，同时对其作出了前景展望。     

Virus Location and Lymphocyte Apoptosis in Lymph Nodes of Piglets Infected with PCV-2

The present study has been performed to understand the location of the virus, type of apoptotic cells, and their relation to lymph nodes of piglets infected with porcine circovirus type Ⅱ （PCV-2）. Nine 32-day-old conventional piglets free of infection with PCV-2 were used, and distributed into three groups： control group （n = 3）, piglets inoculated with PCV-2 alone （PCV-2, n = 3）, and PCV-2 inoculated and KLH immunostimulated group （PCV-2 ＋ KLH, n = 3）. Superficial inguinal lymph nodes from all piglets were collected for histological examination after 32 days postinoculation, and immunohistochemistry for PCV-2 detection. Location of apoptotic cells was detected with TdT-mediated dUTP nick end labeling （TUNEL） and cell cycle, and the apoptotic rates were measured by flow cytometry. The characteristic histopathological lesions of the piglets in PCV-2 and PCV-2 ＋ KLH were lymphocyte depletions in the cortex and paracortex of the lymph nodes, epithelioid-like macrophage infiltration, and intracytoplasmic inclusion bodies presented in epithelioid-like macrophages. PCV-2 was mainly found in epithelioid-like macrophages by immunohistochemistry. In the lymph nodes, lymphocytes presented higher apoptotic rates in the cortex by TUNEL, special B-cell areas, and similar apoptotic cells were found in this compartment in the control. The apoptotic rates of the lymph nodes were 0.41, 3.34, and 4.88% in the control, PCV-2, and PCV-2 ＋ KLH groups by flow cytometry, respectively. The apoptotic rates of lymph nodes for PCV-2 and PCV-2 ＋ KLH piglets were significantly higher than those for the control group （P〈0.05 and P〈0.01）. The proliferation index （PI） was 0.17_＋0.01, 0.12_＋0.01 and 0.12_＋0.04 in the control, PCV-2, and PCV-2 ＋ KLH group, the PI of the control group was higher than that of the other groups, but without the statistical difference. PCV-2 can induce lymphocyte depletion in lymph nodes of piglets by blocking cell proliferation and promoting apoptosis. This is one o     

市级综合气象信息分析与管理系统的设计与实现

以抚顺地区3个国家基本站50余年气象资料为依托，采用Microsoft Excel工作表实现由气候和农业气候2部分构成的气象与农业综合信息处理系统的基本思路、方法、内容、用途和使用情况。为了实现气候分析及应用的科学化、客观化、系统化、规范化、程序化及连续化的业务目标，按业务流程设计与实现的，包括资料处理、气候趋势模拟、气候预测、气候鉴定、季节性信息化处理、农作物产量预报、气候生产潜力分析等一系列内容在内的系统建设。关键是解决了大量的计算问题，建立了区域性通用模式。     

Multi-variable grey model (MGM (1,n,q)) based on genetic algorithm and its application in urban water consumption

Urban water consumption has some characteristics of grey because it is influenced by economy, population, standard of living and so on. The multi-variable grey model （MGM（1,n））, as the expansion and complement of GM（1,1） model, reveals the relationship between restriction and stimulation among variables, and the genetic algorithm has the whole optimal and parallel characteristics. In this paper, the parameter q of MGM（1,n） model was optimized, and a multi-variable grey model （MGM（1 ,n,q）） was built by using the genetic algorithm. The model was validated by examining the urban water consumption from 1990 to 2003 in Dalian City. The result indicated that the multi-variable grey model （MGM（1,n,q）） based on genetic algorithm was better than MGM（1,n） model, and the MGM（1,n） model was better than MGM（1,1） model.     

Molecular detection of virulence genes in Campylobacter species isolated from livestock production systems in South Africa

Campylobacter species are a major cause of foodborne bacterial infections in both developed and developing countries worldwide. Campylobacter jejuni is responsible for the majority of infections. This study was conducted to identify virulenceassociated genes in Campylobacter species isolated from livestock production systems in South Africa. A total of 250 fecal samples consisting of cattle(n=50), chickens(n=50), goats(n=50), sheep(n=50) and pigs(n=50) were randomly collected from livestock in Eastern Cape and KwaZulu-Natal provinces of South Africa between April and October 2018. The samples were analyzed for the presence of virulence genes in Campylobacter species using molecular PCR-based methods. It was found that 77 and 23% of Campylobacter jejuni and Campylobacter coli respectively were isolated from all the livestock samples. There were positive significant(P0.05) correlations amongst all the virulence genes that were investigated. Chisquare and Fisher's exact tests were implemented to test for the effect of livestock species on the presence or absence of virulence genes. The study demonstrated that most of livestock species can potentially cause zoonotic infections and food poisoning due to the high prevalence of Campylobacter. The high prevalence of virulence genes highlights the significance of Campylobacter in livestock production systems in South Africa. This requires the implementation of one-health approaches to reduce the impact of foodborne and zoonotic diseases for the welfare of human and animal health.     

不同施肥水平对木薯氮磷钾养分积累、分配及其产量的影响

 【目的】通过比较不同施肥水平下木薯氮磷钾养分积累、分配和产量的差异，探讨粤北坡岗地优质高产木薯氮磷钾养分的最佳用量。【方法】以木薯品种南美119为材料，采用“3414”方案，在粤北翁源进行大田试验。试验共设14个处理。【结果】施肥处理的氮素主要分配到地上部，不施肥处理的氮素则主要分配到根部；不同施肥处理的磷素均主要分配到地上部；不施肥处理和不施钾处理的钾素主要分配到根部，不施氮处理的钾素在根、冠间分配较均衡。在木薯不同生长阶段，植株氮磷钾含量均呈下降趋势，但施氮、磷、钾化学肥料处理植株氮磷钾含量的下降速度小于不施氮、磷、钾化学肥料的处理。处理N2P2K2的氮、磷、钾含量和积累量在各生育期均为最大，不施肥处理（N0P0K0）的氮、磷、钾含量和积累量在各生育期均为最小（P＜0.05）。产量最高的是N2P3K2处理，为22 694.06 kg·hm-2，其次是N2P2K2处理，为21 417.87 kg·hm-2。【结论】木薯产量、氮磷钾养分积累及其在根冠间的分配，对施肥水平高度敏感, 适当比例的氮磷钾肥配合施用既可以显著增加木薯植株的氮磷钾含量和积累量，又可以提高产量。在粤北坡岗地木薯生产中，氮素最重要，在氮素得到满足的条件下，磷素较钾素更重要。在本试验条件下，氮磷钾养分最佳用量为358.80 kgN·hm-2、89.10 kg P2O5·hm-2和187.50 kg K2O·hm-2。     

红苕饲粮中添加铜和/或喹乙醇对猪生产性能及某些血液生化指标的影响

选体重约38公斤的长白(♂)×成华(♀)杂交猪20头,随机分为四组,饲予四种不同的饲粮,研究饲粮中添加铜和/或喹乙醇对猪生产性能和某些血液生化指标的影响。结果表明:基础组、加铜组、加喹乙醇组和两者同时加组全期日增重分别为674、761、796、678克,日采食量分别为2.50、2.65、2.74、2.40公斤,饲料利用率分别为3.73、3.49,3.44、3.54,添加铜和/或喹乙醇对试验第65天血清铜兰蛋白、尿素氨及屠宰率、背膘厚和眼肌面积无显著影响(p>0.05);添加铜使65天血清碱性碱酸酶活性极显著增高(p<0.01),添加喹乙醇有使之升高的趋势,两者同时添加时,碱性酸磷酶活性降低。     

Current progress on genetic interactions of rice with rice blast and sheath blight fungi

Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.     

仙人掌超氧化物歧化酶提取与纯化研究

以仙人掌为试验材料,采用硫酸铵分级沉淀法得到超氧化物歧化酶（Superoxide Dismutase,SOD）粗酶液。然后用Sephadex（葡聚糖凝胶）G-75层析柱层析对粗酶液进行进一步纯化,最后用邻苯三酚法测定酶活力,并对酶活力主要影响因素（包括pH值、温度、抑制剂）进行了研究。结果显示仙人掌SOD酶比活力为751.56U.mg-1。pH值为7.5~8.5时酶活力最大,稳定性也好。温度维持在25~30℃时酶活力最高。由于过氧化氢和氰化钾均能使仙人掌SOD的酶活力显著下降,因而可以初步判断从仙人掌中提取到的SOD是Cu.Zn-SOD。     

锌对镉·汞复合污染下豌豆幼苗生长的影响

以豌豆为试验材料,采用水培方法研究了锌对镉、汞复合污染下的豌豆种子萌发与生长的影响。结果显示,锌浓度≤100.0 mg/L时促进豌豆种子的萌发,锌浓度为200.0和300.0 mg/L时抑制豌豆种子的萌发。当镉、汞的浓度为3.0 mg/L时,100.0 mg/L锌的解毒效应最明显,表现为能够促进镉、汞胁迫下豌豆种子萌发和幼苗生长,降低豌豆幼苗根尖细胞畸变率,提高豌豆幼苗的叶绿素含量及过氧化物酶活性;但当锌浓度≥200.0 mg/L时,与镉、汞协同迫害豌豆幼苗的生长。