两种不同耐热性菜豆品种在高温胁迫下叶绿素a荧光参数的差异

以两个耐热性不同的菜豆品种85-CT(耐热)和BBL-47(热敏感)为试材,研究其在不同高温胁迫强度下叶绿素a荧光参数的差异,结果表明:两个品种的叶绿素荧光Fv/Fm及Fv/Fo、电子传递速率(ETR)、均随高温胁迫时间延长呈下降趋势,但耐热品种85-CT下降幅度较热敏感品种BBL-47平缓,BBL-47随高温胁迫时间延长,其叶绿素a荧光诱导动力学曲线中的第二峰(M峰)消失。     

移植胁迫对枣苗叶片叶绿素a荧光参数的影响

[目的]为了研究移植胁迫对枣苗叶片叶绿素a荧光参数的影响。[方法]移栽前对1年生灰枣嫁接苗进行不同程度的晾晒胁迫处理,试验分为蘸浆、晾晒0.5、1、1.52、d和留床苗(CK)6个处理,测定其叶绿素a荧光参数。[结果]结果表明:移植胁迫并没有改变灰枣叶绿素a荧光参数的日变化进程,却使枣树的初始荧光(Fo)、最大荧光(Fm)和可变荧光(Fv)升高,原初光能转化效率(Fv/Fm)和PSII潜在活性(Fv/Fo)及实际光化学量子效率(ΦPSII)降低,这些指标的升高或降低幅度随胁迫程度的增强而增大。[结论]该研究为苗木移栽的生产实践提供了理论依据。     

阿克苏市5个枣引种品种叶绿素荧光特征比较

测定比较了阿克苏市5个枣引种品种的初始荧光(Fo)、最大荧光(Fm)、PSⅡ最大光能转化效率(Fv/Fm)和PSⅡ最大光能转化潜力(Fv/Fo)4个叶绿素荧光参数随太阳总辐射、空气温度和空气相对湿度变化的日变化以及不同作用光强下从初始荧光上升到最大荧光一半所需时间(T1/2)的变化特征。结果表明:5个枣品种的叶绿素荧光参数Fv/Fm、Fv/Fo、Fo、Fm的品种间差异均达到了极显著水平(P<0.001),而且在时间序列上Fv/Fm、Fv/Fo、Fo和Fm也均表现为差异极显著(P<0.001);骏枣、金丝小枣的Fv/Fm值全天保持较高水平,灰枣、赞皇大枣的Fv/Fm日均值处于较低状态,且赞皇大枣的Fv/Fm和Fv/Fo日均值显著低于其它品种;除骏枣、金丝小枣的叶绿素荧光参数T1/2下午相比上午变化不是很明显外,其它品种均有不同程度的降低,表明下午的强光、高温和低空气湿度使得PSⅡ活性下调,PSⅡ光合电子传递链受阻,从而发生了光抑制。测试品种耐光抑制能力的强弱为:骏枣耐光抑制能力最强,金丝小枣、羊角枣其次,灰枣、赞皇大枣耐光抑制能力最弱。     

UV-B辐射胁迫对细叶青冈幼苗叶绿素荧光特性的影响

通过对在自然生境(CK)、辐射UV-B增强(+10％)和辐射UV-B减弱(-80％)三种条件下的细叶青冈幼苗叶绿素含量、荧光参数Fv/Fm、Fv/Fo和φPSⅡ的测定研究,探讨UV-B辐射胁迫对细叶青冈生长的影响.结果表明,细叶青冈幼苗在辐射UV-B减弱胁迫下叶绿素含量、荧光参数Fv/Fm、Fv/Fo和φPSⅡ均高于辐...     

干旱胁迫对东岳红光合特性、叶绿素荧光参数及叶片相对含水量的影响

以葎叶蛇葡萄品种东岳红为试材,将一年生扦插苗移栽于花盆中,设置4个不同梯度干旱胁迫处理,研究干旱胁迫对东岳红光合特性、叶绿素荧光参数、叶片相对含水量的影响。结果表明:随着干旱胁迫程度的增加,东岳红叶片净光合速率(Pn)、气孔导度(Gs)呈现先上升后下降的趋势,蒸腾速率(Tr)显著下降,叶片胞间CO_2浓度(Ci)呈现先下降后上升的趋势。干旱胁迫下叶绿素荧光参数Fm、Fv/Fm、Fv/Fo下降,Fo随着干旱胁迫时间的延长呈现上升的趋势,叶片相对含水量呈先缓慢下降后上升的趋势。     

NaCl胁迫对普陀樟叶绿素荧光参数的影响

[目的]探讨NaCl胁迫对普陀樟叶绿素荧光参数的影响。[方法]以1年生普陀樟叶片为试材,采用田间试验的方法,设置3种处理(NaCl溶液浓度分别为3、5、7 g/L),以清水为对照(CK),研究盐处理对苗木生长量、叶绿素含量及叶绿素荧光参数的影响。[结果]NaCl胁迫下,普陀樟苗高生长量下降,叶片的叶绿素含量下降趋于平稳;PSⅡ潜在活性(Fv/Fo)、原初光能转化率(Fv/Fm)变化一致,整体呈上升趋势;随NaCl胁迫的加剧,Fo变化最明显,叶绿素荧光参数间相关性先增强后减弱。[结论]普陀樟具有较好的抗盐性和广泛适应性。     

新疆7种城市园林绿化树种叶绿素荧光特征比较

测定比较了新疆7种城市园林绿化树种的初始荧光(Fo)、最大荧光(Fm)、PSⅡ最大光能转化效率(Fv/Fm)和PSⅡ最大光能转化潜力(Fv/Fo)4个叶绿素荧光参数随太阳总辐射、空气温度和空气相对湿度变化的日变化以及不同作用光强下从初始荧光上升到最大荧光一半所需时间(T1/2)的变化特征.结果表明:随太阳辐射的增强、空气温度的升高和空气相对湿度的降低,7种测试树木的叶绿素荧光参数Fv/Fm逐渐降低,均在中午光照较强时段维持在较低水平;7种测试树木叶绿素荧光参数Fv/Fm,Fv/Fo的种间差异达到了显著水平(P<0.05),Fo,Fm的种间差异达到了极显著水平(P<0.001),在时间序列上Fv/Fm,Fv/Fo,Fo和Fm均表现为差异极显著(P<0.001);圆冠榆、倒榆的Fv/Fm值全天保持较高水平;黄太平、榆叶梅、黄果山楂的Fv/Fm日均值处于较低状态;除黄太平的叶绿素荧光参数T1/2下午相比上午变化不是很明显外,其他树种均有不同程度的降低,表明下午的强光、高温和低空气湿度使得PSⅡ活性下调,PSⅡ光合电子传递链受阻,从而发生了光抑制.测试树种耐光抑制能力的强弱为:榆科的圆冠榆、倒榆耐光抑制能力最强,木犀科的紫丁香、大叶白蜡其次,蔷薇科的黄太平、榆叶梅、黄果山楂耐光抑制能力最弱.     

干旱胁迫下人工种植的甘草叶片叶绿素荧光动力学参数的日变化

以1年生、2年生人工种植甘草实生苗为试验材料,于花期至结果期人为控水模拟干旱胁迫处理1个月,利用OS1-FL便携式叶绿素荧光仪测定甘草叶片的叶绿素荧光动力学参数的日变化。结果表明:2年生甘草叶片荧光动力学参数Fv/Fm、Fv/Fo、Fm/Fo及Fv在干旱胁迫后均以测定当日的15:50为最低值,1年生甘草叶片荧光动力学参数则以测定当日的11:50为最低。1、2年生甘草叶绿素荧光参数Fo及Fm在测定当日均随时间增长呈下降趋势,初步说明干旱胁迫下1年生、2年生人工种植甘草都存在一定程度的光抑制现象。     

Cd、Pb胁迫下湿地匍灯藓（Plagiomnium acutum）叶绿素荧光特性研究

采用浸没培养实验研究了不同浓度Cd(0、1、5、10 mg·L-1)、Pb(0、10、25、50 mg·L-1)单一以及二者低、中、高浓度组合复合处理对湿地匍灯藓(Plagiomnium acutum)叶绿素荧光以及细胞膜透性的影响。结果表明:(1)湿地匍灯藓Fv/Fm、Fv/Fo、Fv′/Fm′、ETR、Y(II)的下降程度与Cd、Pb胁迫浓度及胁迫时间存在明显的剂量、时间-效应关系;随胁迫时间延长,Y(NO)总体呈现持续上升的趋势,qN表现为先升后降,而qP则呈现出先降后升趋势。(2)湿地匍灯藓的叶绿素荧光参数对Pb、Cd胁迫的响应存在差异,单一Pb胁迫初期各荧光参数即出现不同程度的下降,单一Cd胁迫下上述参数均在处理第4 d才出现明显下降;在胁迫第1 d,中、低浓度Cd、Pb单一及复合胁迫均引起湿地匍灯藓的Fv/Fm、Fv/Fo、Fv′/Fm′增加。(3)Cd、Pb胁迫均使处理液电导率升高,升幅大小顺序为Cd/Pb复合胁迫Cd胁迫Pb胁迫。表明湿地匍灯藓在Cd、Pb胁迫初期可通过应激性增加PSII活性中心数来抵御重金属的毒害,但由于电子传递和热耗散能力较弱,使PSII活性中心受损,最终导致光合系统损伤;Cd、Pb复合胁迫对湿地匍灯藓细胞膜的损伤和毒害作用显著强于单一胁迫,Cd对细胞膜的毒害作用又强于Pb;Fv/Fo可作为Cd、Pb胁迫的敏感指标。     

7种箬竹抗寒特性比较

为探明7种箬竹Indocalamusspp.的抗寒特性,利用叶绿素荧光技术测定了夜间低温胁迫后7种箬竹叶绿素荧光参数的日变化。结果表明:各种箬竹PSⅡ实际光化学量子产量日变化规律呈近似“W”型;广东箬竹Indocalamus guangdongensisPSⅡ光化学效率(Fv/Fm),PSⅡ潜在活性(Fv/Fo)和PSⅡ实际光化学量子产量等参数值均低于其他箬竹种;小叶箬竹I.pumilus具有最高的初始荧光(Fo)和最大荧光(Fm)值;髯毛箬竹I.barbatus的Fv/Fm,Fv/Fo值均高于其他几种箬竹,说明广东箬竹最容易遭受低温胁迫,抗寒性差,而小叶箬竹和髯毛箬竹抵抗低温能力较强。可见,利用叶绿素荧光分析技术来鉴别箬竹种间抗寒性是可行的。图4表3参15     

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。