壳寡糖席夫碱对感染烟草花叶病毒烟株叶绿素含量的影响

测定5种壳寡糖席夫碱3个浓度对烟草花叶病毒的抑制效果,结果显示,壳寡糖席夫碱对烟草花叶病毒(TMV)具有一定的诱导抗病效应,其中100μg/mL的3,5-二氯水杨醛壳寡糖席夫碱药剂的效果最好。并用该药剂对豫烟5号进行处理,测定了其对烤烟叶片中叶绿素含量变化的影响。结果表明,壳寡糖席夫碱可以有效诱导烟草抗烟草花叶病毒活性,处理后的烟草叶片中的叶绿素和胡萝卜素含量较阳性对照有较大的提高。     

壳寡糖诱导对烟草花叶病病情发展的影响

在温室控制条件下,研究了壳寡糖诱导处理对烟草花叶病病情增长的影响。采用不同浓度的壳寡糖(10、50、100、150和200μg/mL)分别处理烟草后24 h,再接种烟草花叶病毒(TMV),结果表明,壳寡糖处理使花叶病显症延迟,系统症状明显减轻。未喷药对照与壳寡糖处理的病情发展曲线都可拟合Logistic模型,但壳寡糖处理的模型参数不同。数据分析表明,达到5级严重度所需天数、病害严重度降低率和病情发展曲线下面积(AUDPC)都大幅度降低。在壳寡糖的各浓度间,以50μg/mL对病情增长的影响最大,其次为10μg/mL,其余浓度都较小。结果证明壳寡糖的作用特点符合系统诱导抗病性的性质。     

多脂大戟中Lathyrane-type类二萜化合物对烟草花叶病毒的抑制活性分析

【目的】烟草花叶病毒(Tobacco mosaic virus, TMV)严重危害烟草、番茄、辣椒等多种作物,给农业生产造成巨大经济损失,本研究为利用低毒、高效植物源药剂防治TMV病毒病害提供先导化合物和理论依据。【方法】采用枯斑计数法对从多脂大戟中分离的11种化合物进行抗TMV活性测定。【结果】接种TMV 24 h后施用100μg/mL的化合物制剂进行防控实验,其中化合物Euphorblin E (HZ-7)的抑制率为67.54%,高于对照宁南霉素(52.89%);先施用11种化合物制剂6 h后再接种TMV进行预防实验,其中化合物Euphorblin E (HZ-7)抑制率为72.29%,高于对照宁南霉素(58.21%)。【结论】多脂大戟中化合物Euphorblin E可作为抗TMV病毒病害环保型生物源农药研发的先导化合物。     

核桃青皮中低极性组分抗TMV作用机制研究

为揭示核桃青皮中低极性组分的抗病毒机制,本研究以核桃青皮中低极性组分为处理药剂对烟草花叶病毒(TMV)进行预防和治疗处理,测定了K326叶片中与抗病毒性相关的部分生理生化指标的变化.结果表明,核桃青皮中低极性组分预防和治疗处理均可使K326叶片内的叶绿素和可溶性蛋白含量升高,MDA含量降低.POD和PPO的活性增强,可见,核桃青皮中低极性组分可诱导植物产生抗病性,增强烟草对TMV侵染的抵抗力.     

烟草根系分泌物成分的鉴定及其对烟草疫霉菌的影响

[目的]探究烟草根系分泌物不同成分对烟草疫霉菌的影响。[方法]利用液质联用法鉴定烟草革新3号根系分泌物的成分,采用生长速率法测定烟草根系分泌物的抑菌效应。[结果]相对含量较高的32种烟草根系分泌物中,有12种分泌物对烟草疫霉菌具有抑制作用,5种具有促生作用;在800μg/mL浓度处理下,酒石酸、水杨酸、2-呋喃甲酸和土木香内酯对烟草疫霉菌抑制率分别为92.87%、97.14%、91.33%和93.76%,以水杨酸的抑菌效果最佳,与对照相比,其EC50均小于500μg/mL,其中酒石酸的毒力最强,EC50为159.68μg/mL。[结论]酒石酸、水杨酸、2-呋喃甲酸和土木香内酯4种根系分泌物对烟草疫霉菌有较好的生防效应。     

草酸青霉菌果胶酶诱导烟草抗TMV的研究

本试验就草酸青霉菌(Penicillium oxalicum)的固态发酵提取产物——果胶酶粗酶液诱导烟草对烟草花叶病毒(TMV)的抗性进行了研究。以不同浓度果胶酶粗酶液喷雾处理2个烟草品种,超过100 U/mL的各浓度处理,病斑抑制率均达到50%以上。通过果胶酶诱导烟草抗病的时效性、加强诱导的效果、系统诱导抗病性、处理方法不同对烟草抗TMV效果以及果胶酶液对TMV病毒毒性的研究,结果表明:诱导处理2、4d后接种TMV病毒,果胶酶的诱导抗病效果最明显,病斑抑制率在50%左右;二次加强诱导处理可以提高烟草抗TMV的效果;果胶酶可诱导烟草产生对TMV的系统获得抗性;叶面喷雾果胶酶处理方法,对烟草抗TMV的效果最显著;果胶酶液中不含有影响TMV致病力的因子。由此表明,果胶酶对TMV的防治是通过激发烟草植株体内一系列抗病防御反应而增强自身抗病能力的。     

8种杀菌剂对烟草赤星病菌的室内毒力测定

采用生长速率法测定了8种杀菌剂对烟草赤星病的室内毒力,结果表明：8种药剂在试验浓度下对烟草赤星病菌菌丝的生长具有不同程度的抑制作用,其中以10%苯醚甲环唑WP的效果最好,其EC50为7.45μg/mL;15%噁霉灵WP和25%咪鲜胺EC次之,EC50分别为16.26μg/mL及23.57μg/mL;80%百菌清WP效果最差,其EC50为111.71μg/mL。     

博落回生物碱对烟草蚜和豆蚜杀虫活性的研究

博落回总生物碱、总生物碱盐酸盐对烟草蚜虫、豆蚜虫都有比较强的毒杀作用,处理60 h,博落回总生物碱、总生物碱盐对烟草蚜虫半致死浓度LC50分别为274.5μg/mL和501.19μg/mL。博落回总生物碱(处理48 h)、博落回总生物碱盐(处理30 h)对豆蚜虫半致死浓度LC50分别为562.3μg/mL和380.2μg/mL。     

白术提取物抗TMV生物活性初探

以烟草花叶病毒(TMV)为供试病毒,采用半叶枯斑法测定了白术提取物对TMV的生物活性.结果表明:在供试浓度为10 g/L时,白术石油醚提取物对TMV具有明显的体外钝化作用,钝化0.5h后,其抑制率达61.86％;对TMV的初侵染和增殖也有一定的抑制作用,处理24 h后,抑制率分别为40.12％和20.03％.白术中抗病毒的活性成分主要存在于石油醚萃取物中.     

6种杀菌剂对苹果轮纹病的毒力测定

采用生长速率法测定了6种杀菌剂对苹果轮纹病菌的毒力。结果表明,氟硅唑、戊唑醇、多菌灵对菌丝的抑制作用最为明显,氟硅唑在处理剂量为0.800μg/mL时,抑制率为96.04%;戊唑醇在处理剂量3.200μg/mL时,抑制率为96.21%;多菌灵在处理剂量0.320μg/mL时,抑制率为92.20%。氟硅唑和多菌灵对苹果轮纹病菌的毒力较强,EC50分别为0.038 52μg/mL和0.067 54μg/mL;其次为戊唑醇和吡唑醚菌酯,EC50分别为0.154 8μg/mL和1.504 23μg/mL;苯醚甲环唑和异菌脲EC50分别为4.357 08μg/mL和4.875 82μg/mL。苯醚甲环唑对苹果轮纹病菌的毒力最弱。     

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。     

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.     

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     

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。     

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。