竹醋液作为植物生长调节剂的开发研究:(Ⅰ)室内试验

采用萝卜、黄瓜和小麦的幼苗生长法, 萝卜和黄瓜的子叶扩张法以及藻类生长测试法等联合方法分别对原竹醋液和中和竹醋液进行室内生物活性筛选试验.结果表明:(1)高浓度竹醋液(2 000～5 000 mg/L)抑制作物生长,具有除草剂活性;低浓度(＜500 mg/L),具有植物生长调节剂功效,其功能与2,4-D类、激素类除草剂相似;也与植物生长调节剂GA3和6-BA具有相似的功效;(2)中和竹醋液的效果明显高于原竹醋液;(3)几种筛选指示物的敏感性从高到低的顺序为:水华微囊藻＞四尾栅藻＞萝卜(黄瓜)子叶＞黄瓜根茎长＞萝卜根茎长＞小麦根茎长,其中对于黄瓜、萝卜和小麦,根长敏感性均高于茎长.     

低频再生黄瓜离体培养体系的优化

【目的】优化低频再生黄瓜离体培养体系,为黄瓜遗传转化体系的进一步完善奠定基础。【方法】以低频再生黄瓜种质Q24和L66为材料,分别以黄瓜的子叶、子叶节和下胚轴为外植体,研究外植体类型对黄瓜再生频率的影响;在MS培养基中添加不同质量浓度6-苄基腺嘌呤(6-BA)和脱落酸(ABA),研究激素配比对黄瓜再生频率的影响;将获得的黄瓜子叶节外植体置于1/2 MS培养基上预培养0,1,2,3和4 d,研究预培养处理对黄瓜再生频率的影响。【结果】不同基因型黄瓜再生频率差异显著,其中Q24整体上具有相对较高的再生频率,其子叶节再生频率为54.8%,下胚轴再生频率为50.0%;L66的再生频率相对较低,其子叶节再生频率为36.9%,下胚轴再生频率为16.7%。激素配比显著影响黄瓜子叶节外植体的再生频率,其中1.00 mg/L ABA+1.00 mg/L 6-BA对Q24子叶节不定芽的诱导效果最好,再生频率达到60.7%;2.00 mg/L ABA+1.00 mg/L 6-BA对L66子叶节不定芽的诱导效果最好,再生频率达到42.9%。预培养处理可显著提高L66子叶节的再生频率,经过1～3 d预培养,其再生频率逐渐增加并达到最高(32.1%),4 d后再生频率开始降低;Q24子叶节经3 d预培养再生频率达到最高,为27.4%,但与对照相比差异不显著。【结论】Q24子叶节外植体最适激素配比为1.00 mg/L ABA+1.00 mg/L 6-BA,经3 d预培养后其再生频率可达60.7%;L66子叶节外植体最适激素配比为2.00 mg/L ABA+1.00 mg/L 6-BA,经3 d预培养后再生频率可达42.9%。     

切割子叶对黄瓜子叶离体培养及去顶苗直接成花的影响

黄瓜离体子叶培养时,整片子叶培养形成花芽的百分率明显高于切除部分子叶的花芽形成的百分率。切除黄瓜幼苗１／２子叶明显促进黄瓜幼苗去顶芽后直接形成花芽的百分率。纵向切除１／２子叶不利于直接花芽的形成。     

黄瓜白粉菌基因组DNA 提取方法比较

以黄瓜白粉病菌为试验材料,比较分析了改良CTAB法、SDS法和真菌试剂盒法对黄瓜白粉病菌基因组DNA提取的效果。结果表明,CTAB法提取的黄瓜白粉菌基因组DNA在纯度(R=A_(260 nm)/A_(280 nm))和产量上均优于SDS法和真菌试剂盒法,且杂质少。CTAB法提取的黄瓜白粉菌基因组DNA产率为204.3μg/g,而SDS法和真菌试剂盒法分别为147.7、117.7μg/g,且方法产率之间差异极显著。采用CTAB法提取的DNA纯度较高,为1.969 6;SDS法和真菌试剂盒法提取的DND纯度较低,分别为1.832 2和1.507 9。     

砧木子叶剪除量对嫁接黄瓜生长发育的影响

为黄瓜穴盘嫁接育苗生产提供技术支持,以迷你黄瓜为试材,研究了砧木嫁接前子叶不同剪除量对穴盘黄瓜嫁接幼苗生长性状、植株生长发育、果实产量及品质等方面的影响。结果表明：黄瓜嫁接幼苗长势以砧木子叶剪叶1/2处理的最强,其次为不剪叶处理;根系活力以不剪叶处理最强,极显著大于剪叶处理,剪叶处理之间无显著差异;叶片丙二醛含量随着剪叶量的增大而减小。剪叶处理与不剪叶处理植株的生长势、产量、品质、果实表面蜡粉量、白粉病病情指数和根体积均无显著差异。部分剪除砧木子叶对嫁接黄瓜的生长发育无不良影响,以嫁接前剪除砧木1/2子叶面积为最佳处理。     

植物提取液对黄瓜白粉病的抑菌活性筛选研究

首先通过叶圆盘法用29种植物提取液对黄瓜白粉病菌的抑菌效果进行了生物活性测定,初步筛选出槐、黄檀、南瓜和石楠等4种植物的提取液对黄瓜白粉病有较好的预防效果。然后对这4种植物提取液进行预防性和治疗性的室内盆栽药效试验,结果表明黄檀提取液对黄瓜白粉病的预防效果达到72.97%,治疗效果达到91.28%,并且在处理12 d后仍保持42.60%以上的防效。而槐提取液的预防效果和治疗效果分别为79.73%和79.19%,处理12 d后也保持在50%以上的防效。这两种植物提取液均极显著优于对照药剂三唑酮。     

光与植物激素对黄瓜离体子叶衰老的延缓效应

研究了光与3种不同植物激素对黄瓜(Cucumis sativus L．)离体子叶衰老的影响。结果表明：3种植物激素都能减缓黄瓜离体子叶的叶绿素含量、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的下降，还能降低丙二醛(MDA)含量和电导率增量的增加；比较不同激素的作用效应，其中激动素(KT)和玉米素(ZT)延缓叶绿素含量下降效果最明显，而6-BA对降低MDA的积累和电导率的增加效果最好。另外，光和暗处理的结果显示，光能延缓黄瓜离体子叶的衰老。     

切割子叶地黄瓜子叶离体培养及去顶育苗直接成花的影响

黄瓜离子体子叶培养时，整片子叶培养形成花芽的百分率明显高于切除部分子叶的花芽形成的百分率，切除黄瓜幼苗１／２子叶明显促进黄瓜幼苗去顶芽后直接化芽的百分率，纵向切除１／２子叶不利于直接花芽的形成。     

春雷霉素与叶枯唑对黄瓜细菌性角斑病菌的联合毒力

为明确春雷霉素(Kasugamycin)与叶枯唑(Bismerthiazol)混配对黄瓜细菌性角斑病菌(Pseudomonas syringe pv.lachrymanas)的增效作用及最佳配比,采用浑浊度法测定了春雷霉素与叶枯唑混配对黄瓜细菌性角斑病菌的毒力。结果表明:春雷霉素、叶枯唑对黄瓜细菌性角斑病菌的EC50分别为8.739、39.227mg·L-1,春雷霉素对黄瓜细菌性角斑病菌的室内生物活性明显高于叶枯唑;春雷霉素与叶枯唑混配对黄瓜细菌性角斑病菌表现为增效作用,5个配比中,1∶5配比的SR为1.71,增效作用最明显。     

黄瓜苗期管理抓什么?

黄瓜出土后子叶(最初的两片叶)生长快,同时嫩茎也容易徒长,群众称这种现象为“拉腿”。真叶(第三片及后来的叶子)展开后,花芽开始形成。因此黄瓜苗床的管理工作,需从以下两方面抓起:     

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。