甜菜铵转运蛋白BvAMT1-3基因的克隆及生物信息学分析

在植物体内,由铵转运蛋白(Ammonium transporters, AMTs)介导植株对铵态氮的吸收和转运。氮素在甜菜糖代谢的过程中起着重要作用,对甜菜AMTs蛋白的功能特性及调控机制进行生物信息学分析对于解析甜菜AMT基因家族的分子功能具有重要意义。本研究通过RT-PCR的方法,在甜菜体内克隆获得了Beta vulgaris ammonium transporter 1-3(BvAMT1-3)基因的全长序列。生物信息学分析结果显示该基因大小为1 388 bp,编码462个氨基酸,分子量约为49.729 kDa,亚细胞定位分析其位于内质网膜结构上的可能性较大。系统进化分析显示5个甜菜AMT蛋白序列可分成2个亚族,AMT3亚族仅有1个成员,其余为AMT1亚族成员,同时甜菜BvAMT1-3蛋白与菠菜SoAMT1-3蛋白的亲缘关系最近。5个AMT基因家族成员均由α-螺旋、β-折叠、扩展链以及无规则卷曲4种形式组成。BvAMTs基因家族间的等电点、亲水性、相对分子质量等理化性质存在差异。此外,BvAMT1-3基因的启动子区检测到与植物逆境胁迫、光反应和生长发育相关的顺式作用元件。研究结果可为后续甜菜BvAMT1-3基因在氮胁迫逆境下分子机制的研究提供一定的科学依据。     

花生甘油-3-磷酸酰基转移酶(GPAT)基因的克隆及表达分析

本研究从花生中克隆得到2个GPAT基因,分别命名为AhGPAT3和AhGPAT5。AhGPAT3基因全长为1653bp,编码550个氨基酸;AhGPAT5基因全长为1383bp,编码460个氨基酸,均属于GPATs蛋白质家族。通过实时定量PCR检测克隆到的GPAT基因在花生不同组织、种子不同发育时期、多种非生物逆境胁迫及多种激素处理下的表达模式。结果显示,AhGPAT3与高等植物的GPAT3和GPAT2亲缘关系最近;AhGPAT5与高等植物的GPAT5和GPAT7亲缘关系最近。AhGPAT3和AhGPAT5基因在种子发育初期和下胚轴中的表达量较高;另外,发现AhGPAT3基因很可能参与了花生对低温、高盐和干旱的抗性调节。     

白菜型油菜八氢番茄红素脱氢酶基因PDS3的克隆与序列分析

利用电子克隆技术,从数据库中找到与拟南芥高度同源的油菜EST序列,继而通过RT-PCR和RACE等方法,成功克隆了白菜型油菜八氢番茄红素脱氢酶（类胡萝卜素合成途径中的一个关键限速酶）基因PDS3的cDNA,命名为BrPDS3（GenBank 登记号GQ200741）。cDNA序列全长1940bp,其中包含114bp的5’前导序列和134bp的3’不翻译序列,编码区长度为1 692bp,编码63kD的蛋白。序列分析表明,BrPDS3蛋白与其他植物的PDS蛋白具有较高相似性;在系统进化树中,BrPDS3与甘蓝亲缘关系最近。根据全长cDNA序列设计引物,从白菜型油菜青油13号DNA中克隆得到BrPDS3基因的全长DNA,长度为3 911bp,ORF（开放阅读框）1 692bp,含有15个外显子和14个内含子。     

木薯糖转运蛋白MeSWEET18的克隆与功能分析

木薯（Manihot esculenta Crantz）是热带亚热带地区重要的粮食作物。而SWEET家族基因在植物运输糖类、生殖和发育、植物逆境、与病原体互作等方面发挥着重要作用。为了明确SWEET家族基因在木薯生长发育过程中的功能，本研究以木薯华南9号（SC9）作为实验材料，克隆糖转运蛋白基因MeSWEET18并进行生物信息学分析，通过酵母实验验证其糖转运能力；采用qRT-PCR分析该基因在木薯不同器官及不同发育时期的表达情况以及在非生物胁迫下的表达趋势。结果表明：MeSWEET18基因开放阅读框为714 bp，编码237个氨基酸，蛋白分子质量为25.94 kDa，理论等电点为6.57，不稳定系数为37.50，属于稳定类蛋白。MeSWEET18蛋白N端含有保守结构域MtN3＿slv,C端含有PQ-loop super family保守结构域，且具有7个跨膜结构域，是典型的膜蛋白。ProtScale预测表明MeSWEET18蛋白属于亲水性蛋白。系统进化树分析发现MeSWEET18属于CladeⅣ亚类，与AtSWEET16、AtSWEET17亲缘关系最近；氨基酸序列同源分析显示，MeSW...     

花生NRT1基因对盐胁迫的响应

盐胁迫属于一类重要的非生物胁迫,抑制植物的生长发育,影响植物对营养元素的吸收利用。氮元素是构成生物体核酸和蛋白质的主要元素,在维持植物生命活动以及作物产量和品质等方面有重要作用。设置不同盐胁迫浓度,测定盐胁迫后花生叶片硝酸盐含量,分析NRT1基因家族特征及其对盐胁迫的响应。结果表明,盐胁迫抑制叶片中硝酸盐的积累,并随盐浓度上升叶片中硝酸盐含量下降,推测盐胁迫可能抑制了硝酸盐转运蛋白的表达。硝酸盐转运蛋白1(NRT1)家族是植物中最大的硝酸盐转运蛋白家族。利用生物信息学分析发现,花生基因组中有37个NRT1基因,按亲缘关系的远近可以分成6类。基因结构与表达分析发现,NRT1基因间跨膜区和外显子数目差异较大,在22个不同组织中的表达具有明显的组织特异性。在栽培花生品种Tifrunner中发现了9个对盐胁迫响应的NRT1基因,推测这些基因可能参与盐胁迫条件下氮素的吸收和转运。本研究为深入研究硝酸盐转运蛋白的功能及其在盐胁迫条件下花生氮素吸收转运中的作用奠定了基础。     

丰水梨多酚氧化酶基因的克隆与原核表达

通过PCR方法克隆丰水梨PPO基因全长,并将其登录Genebank,登录号JQ861265。基因全长1782 bp,无内含子,编码的PPO属于亲水性蛋白质,无跨膜结构,含有593个氨基酸,分子量约为65.8 k Da,理论等电点为8.4。N端含有一段由47个氨基酸组成的转运肽。去除转运肽的成熟PPO分子量为60.8 k Da,理论等电点为6.69。PPO中含有两个铜离子结合区,主要位于PPO二级结构中的α-螺旋区域中。原核诱导目的蛋白在诱导3~6 h后积累量较大。诱导蛋白(PPO前体和成熟PPO)均能氧化儿茶素形成茶黄素。     

植物蔗糖转运蛋白研究进展

蔗糖转运蛋白(SUT)在植物的生长代谢中调控蔗糖的运输和分配,并通过蔗糖信号影响其它代谢途径。植物蔗糖转运蛋白结构较为保守,属于12次跨膜的膜蛋白基因家族。对已完成基因组测序的10个单子叶和8个双子叶植物的蔗糖转运蛋白聚类分析表明,该基因家族可以分为5个亚族,SUT1、SUT2、SUT3、SUT4、SUT5,其中SUT2和SUT4为单、双子叶所共有的基因,SUT1为双子叶特异,而SUT3、SUT5为单子叶特异。单、双子叶蔗糖转运蛋白是由2个祖先基因进化而来。SUT的组织分布和遗传转化研究表明,SUT参与植物蔗糖运输与贮存、非生物胁迫响应、胚乳发育等,且SUT家族成员之间存在功能差异。SUT2的表达受Sn RKs调控,而SUT4表达则调控部分生物钟相关基因,同时筛部移动信号等也调节SUT的表达。本文综述了植物蔗糖转运蛋白基因分类、生理功能及其在不同水平上的调控等方面的研究进展,为更好的理解蔗糖转运蛋白对植物生长发育的影响及其分子机制提供参考。     

茶树CsMGTs基因的克隆及其镁转运功能分析

镁离子（Mg²⁺）作为叶绿素的中心成分,是植物细胞中含量最丰富的二价阳离子,也是多种酶的激活剂,特别是茶氨酸合成酶的活性依赖Mg²⁺,常被作为茶树专用肥的特征成分,因此对茶树的生长发育和茶叶的品质形成至关重要。MRS2/MGT家族镁转运蛋白在维持植物体内Mg²⁺的吸收转运、胞内平衡和耐逆性等方面起着重要的作用。为探究茶树MRS2/MGT家族镁转运蛋白基因的功能,以茶树品种陕茶1号为材料,克隆了4条MRS2/MGT镁转运蛋白基因,分别命名为CsMGT1、CsMGT2、CsMGT2.1和CsMGT3。生物信息学分析表明,这4个转运蛋白在C末端均含有2个跨膜结构域和1个保守的GMN三肽基序;系统发育分析显示,CsMGT1属于Clade C成员,而CsMGT2、CsMGT2.1和CsMGT3属于Clade B成员,所编码蛋白与木本植物柑橘MGT家族的亲缘关系最近。实时荧光定量PCR（qRT-PCR）分析表明,CsMGT1、CsMGT2、CsMGT2.1和CsMGT3在茶树的根、茎、叶、花中呈组成型表达,且根和叶对Mg²⁺浓度均表现出不同程度的响应。鼠伤寒沙门氏菌镁转运缺失突变株MM281功能互补试验表明,CsMGT1和CsMGT2均具有Mg²⁺转运功能,且CsMGT1的Mg²⁺转运功能优于CsMGT2,而CsMGT2.1和CsMGT3几乎没有镁离子转运功能。本研究结果丰富了茶树CsMGTs家族的生物学功能,为进一步阐明茶树通过镁转运功能机制实现对镁离子的利用奠定了前期研究基础。     

8个大豆Dof转录因子的生物信息学分析及干旱诱导表达

为探究大豆Dof转录因子的功能,本研究对大豆中8个Dof转录因子的基因序列进行生物信息学分析,通过实时荧光定量PCR检测编码基因在干旱胁迫下的表达,并分析主要应答基因的启动子序列中的顺式作用元件。研究结果显示:8个Dof转录因子编码基因分别位于大豆5、8、11、13、15和16号染色体上,编码蛋白序列的氨基酸残基为213～403个,等电点为6.61～9.36,主要定位于细胞核中。GmDof2与番茄SlDof5.4具有较近的亲缘关系,GmDof1、GmDof8、GmDof3和GmDof5之间具有较近的亲缘关系,GmDof7与黄瓜CsDof1.4具有较近的亲缘关系,而GmDof4和GmDof6具有较近的亲缘关系。GmDof1和GmDof3的表达量在干旱胁迫下上升幅度最明显,启动子序列中均含有多种逆境相关的顺式作用元件。研究结果证明大豆Dof转录因子具有在植物抗旱基因工程中的应用前景。     

普通小麦 TaCAT 9基因的克隆与表达分析

氨基酸转运蛋白是植物体内一类负责氨基酸运输的蛋白,是植物氮代谢的重要媒介。CAT9（阳离子氨基酸转运蛋白9）是氨基酸转运蛋白家族的一员,为深入了解小麦中该基因的序列特征及表达特性,采用同源克隆的方法从普通小麦品种豫麦49-198中获得TaCAT9两个部分同源基因的cDNA序列。因两基因分别位于小麦6 A和6 B染色体长臂上,故分别命名为TaCAT9-A和TaCAT9-B。生物信息学分析结果表明,两个TaCAT9基因的CDS长度均为1 818 bp,编码605个氨基酸;它们的编码蛋白等电点分别为8.23和8.27,分子量分别为64.04 kDa和64.08 kDa,属于疏水稳定蛋白。并且两蛋白均含有阳离子氨基酸转运蛋白的C末端和13个跨膜区。进化分析结果表明,小麦CAT9蛋白与乌拉尔图小麦和山羊草的CAT9蛋白亲缘关系密切。实时荧光定量反转录PCR结果表明,TaCAT9基因在根、茎、叶和籽粒中都有表达,但在叶中的表达量最高;在氮饥饿条件下,该基因的表达上调,推测该基因参与小麦低氮胁迫应答。     

Rain-induced removal of copper from apple leaves: Influence of rain properties and tank-mix adjuvants on deposit characteristics at the micro scale

Application of copper fungicides is an integrative component in the control of apple scab. As shown in the past, tank-mix adjuvants might reduce the rain-induced removal of active ingredients. The aims of this study were a) to characterize the impact of defined rain amount on the removal of Cu-oxychloride (Cu-Ox) and Cu-hydroxide (Cu-Hyd) from apple seedling leaves, b) to examine the influence of ethoxylated seed oil adjuvants on deposit properties at the micro scale and their possible influence in reducing the fungicide erosion from the leaves, and finally c) to evaluate the influence of previous adjuvant application on the rainfastness of copper ions. Losses of Cu-Hyd and Cu-Ox from seedling leaves exposed to 5 mm heavy rain reached almost 80% of the original Cu load. Wash-off extent of Cu-Ox could be reduced by using the rapeseed oil ethoxylate RSO 5 (47%), the linseed oil ethoxylate LSO 10 (47%), or the soybean oil ethoxylate SBO 10 (40%). However, in case of Cu-Hyd, none of the adjuvants was able to increase the tenacity of the copper on the leaves. Rainfall removed the bulky deposits and induced changes in the typical shape of the crystals. Furthermore, a reorganization of the spatial distribution of the remaining active ingredient (a.i.) was induced, which was very often embedded in a thin layer of adjuvants. In general, the adjuvants had a significant impact on droplet spread, whereas the area effectively covered with the a.i. was affected to a lesser extent. For both Cu-Hyd and Cu-Ox rewetting of the original deposit under controlled conditions resulted in an increased spread area but reduced the area effectively covered with Cu. Our results showed no clear relationship between the area covered by Cu ions and their adhesion to the surface, i.e. rainfastness. Finally, our studies indicated that previous spray treatments might influence the rain-induced removal of copper.     

Effect of molybdenum and sulphur on copper status and mohair quality in Merghoze goat

This study was made on the effects of a normal diet containing 12.8 mg Cu kg(-1) DM which added gradually molybdenum and sulphur on the copper status and fibre quality in eight 1-year Merghoze goat. One group (n = 4 mean weight 31 +/- 2.0 kg) was treated with Mo and S supplements for 20 weeks, the second group (n = 4 mean weight 32 +/- 2.1 kg) served as controls. In addition of blood sampling for measuring copper status in plasma, the copper content and quality of fleeces were measured every 6 weeks. Mohair measurements were carried out by taking patch samples (10 x 10 cm2) from the mid-side area of the goat. The analytical set consists of plasma copper concentrations (Pl Cu), Trichloroacetic acid soluble copper concentrations (TCA-Cu), and fleece copper content. The results indicated that the addition of 20-30 mg Mo and 2-2.5 g S kg(-1) DM to the normal diet did produce sub clinical copper deficiency in treated goats. One such visual symptom was the loss of fleeces pigmentation and poorer crimp being observed. The Pl Cu minus TCA-Cu plasma became more than 2 microM in the blood of treated goat, indicating that there was a significant thiomolybdate formation in the body. The results showed that there was a significant decrease in Pl Cu (p < 0.05) along with a significant increase in thiomolybdate (MoS) production after 4 months. The sub clinical signs of copper deficiency and mohair quality are likely to be from high molybdenum intake and thiomolybdate formation in the body.     

Efficacy and environmental fate of copper sulphate applied to Australian rice fields for control of the aquatic snail Isidorella newcombi

Copper sulphate pentahydrate (CuSO₄·5H₂O) is widely used for controlling Isidorella newcombi, an aquatic snail that causes substantial damage to rice crops in southeastern Australia. We conducted field trials on a Birganbigil clay loam soil that demonstrate high levels of efficacy against adult I. newcombi (95% mortality at 6.38 kg ha⁻¹ CuSO₄·5H₂O (1.14 mg Cu L⁻¹)). Dissolved copper fell below the detection limit (0.02 mg Cu L⁻¹) between 7 and 20 d after spraying at application rates up to 2.16 mg Cu L⁻¹ (12 kg ha⁻¹ CuSO₄·5H₂O). Total copper concentrations in the water column fell below the detection limit (0.007 mg Cu L⁻¹) 7–12 d after spraying at initially applied concentrations of 0.52–1.12 mg Cu L⁻¹, but remained detectable (0.01–0.02 mg Cu L⁻¹) until 30 days after spraying (the conclusion of monitoring) when applied at higher initial concentrations (1.18–2.16 mg Cu L⁻¹). There was a strong positive correlation (r² = 0.90, P < 0.001) between copper application rate and copper concentrations in surface sediments 30 d after spraying. Bioassays with immature snails using three different test soils beneath irrigation water showed that underlying soil type strongly influenced the response of snails to applied copper, with significant (P < 0.05) differences between LC₉₀ values which ranged from 0.41 to 1.04 mg applied Cu L⁻¹. Laboratory studies showed that dissolved copper concentrations remained significantly higher (P < 0.05) in the water column above the soil that had the most deleterious effect on copper toxicity. Dissolved organic carbon concentrations were significantly (P < 0.05) higher in both this soil and in the overlying water in the corresponding bioassay system, and correlated more closely with LC₉₀ values than other water chemistry parameters such as total hardness. Our results support the ongoing use of a variable copper application rate of 6–12 kg ha⁻¹ CuSO₄·5H₂O to allow for site-specific variations in efficacy, and suggest that variations in the release of dissolved organic carbon compounds from flooded soils may be a key factor moderating copper toxicity to I. newcombi in rice fields.     

Assessment of retention and persistence of copper fungicides on orange fruit and leaves using fluorometry and copper residue analyses

High volumes of copper hydroxide, cuprous oxide and copper oxychloride were sprayed under natural conditions onto mature orange trees to compare the retention on citrus leaves and fruit over a period of 56 days by means of copper residue analyses and a spray deposition assessment protocol using fluorometry, photomacrography and digital image analyses. Rainfall and increase in fruit size were also recorded to determine if it had an influence on weathering of copper residues. Initial retention following application of the different fungicides differed on Valencia leaves and fruit: applications with cuprous oxide retained significantly more copper residue and fluorescent pigment, while copper hydroxide retained higher copper and pigment levels on Navel leaves and fruit. Nonetheless, persistence of copper residues deposited by the three copper fungicide formulations was similar and decreased at the same tempo during both seasons; initially a fast reduction (48 and 60% for year one and two respectively) in residue during the first 14 days followed by a more gradual decline (41 and 24% for year one and two respectively) from 14 to 56 days. The loss of copper residues was attributed to weathering (days after treatment), fruit growth and cumulative rainfall as these factors were inversely correlated with copper residue levels (Pearson's r = −0.840, −0.722 and −0.733 respectively). A 76% and 90% correlation was observed between the copper residue analyzed and the quantitative fluorescent pigment measurements on mature leaves and fruit, respectively; showing that fruit is more reliable for fluorometry analyses and that this technique proved to be an effective tool for spray deposition and persistence assessment of copper fungicides. All copper formulations tested at these registered rates at 35-day spray intervals were effective in controlling Guignardia citricarpa.     

Interaction of dosage,spray interval and fungicide action in blister blight disease control in tea

Copper oxychloride at three dosage rates, nickel chloride at two rates and a combination of the two at three rates were tested against blister blight of tea (caused by Exobasidium vexans Massee) at six different treatment intervals from June to November, 1981. Under severe monsoon weather conditions, disease incidence exceeded the critical economic threshold limit with both fungicides when applied at intervals longer than 3 days. Only with the combination of copper and nickel was blister blight infection below the critical limit at 5-day spray intervals. When weather conditions were mild in October and November the treatment interval could be safely extended to 11 days with either copper or nickel alone, or both used together. The eradicant nickel chloride was superior to the protectant copper fungicide under severe weather conditions. A strong interaction was evident between dosage, treatment interval, the mode of action of the fungicide and weather conditions in blister blight disease control. The results point to the need in practice for short spray intervals with a copper-nickel combination at 210 g/ha of each from June to September and longer intervals thereafter, for maximum economic control.     

Comparative efficiency of chemical compounds for in vitro and in vivo activity against Clavibacter michiganensis subsp. michiganensis, the causal agent of tomato bacterial canker

Bacterial canker of tomato caused by Clavibacter michiganensis subsp. michiganensis produces considerable economic losses in many countries because effective control measures are lacking. The extent to which bactericides control this disease effectively is low and has not yet been well documented for Southern European conditions. In this study the bactericidal effect of several products on this pathogen was assessed in vitro and in vivo in tomato plants under greenhouse conditions. Seven antibacterial substances (bronopol, copper sulphate, kasugamycin, oxolinic acid, oxytetracycline, streptomycin and 8-hydroxy-quinoline), three commercial formulates (Antibak RZ, an oligoelements mixture containing copper plus zinc; Orthopol, a potassium soap; and Param, a resistance inductor) and combinations thereof were tested. In vitro assessment showed that minimal inhibitory concentration (MIC) of antibacterial substances was between 4–8 μg ml⁻¹, except for copper sulphate with a MIC value of 150 μg ml⁻¹ and kasugamycin, which was not active at 500 μg ml⁻¹. MIC values of commercial formulates ranged between 5 and 40 μl ml⁻¹. Furthermore, combinations of 8-hydroxy-quinoline+copper sulphate, 8-hydroxy-quinoline+Antibak RZ, streptomycin+Antibak RZ and streptomycin+Orthopol showed a synergistic effect at sub-inhibitory concentrations. Treatments containing copper sulphate greatly reduced disease symptoms on plants sprayed with the bacteria, whereas streptomycin was less effective. In two independent trials, the percentage of leaves showing symptoms was significantly lower (2.4% and 11.9%) after treatment with copper sulphate combined with 8-hydroxy-quinoline at half-dose, than in inoculated controls (75.1% and 59.6%). These results were better than copper sulphate alone. However, plants inoculated by pricking rapidly developed systemic infection, which no product managed to control significantly, although several treatments did reduce symptoms. We conclude that copper sulphate combined with 8-hydroxy-quinoline may be useful in controlling external symptoms of this disease in greenhouses, and is environmentally friendly, reducing the amount of copper applied to crops.     

不同产地川佛手中重金属含量测定及安全性评价

建立川佛手重金属含量测定的电感耦合等离子体发射光谱（ICP-OES）分析方法,并对川佛手重金属含量进 行分析与安全评价。样品经微波消解后,用 ICP-OES 方法测定其铅、镉、铜、汞、砷 5 种重金属含量。利用 SPSS 统 计软件对不同重金属元素进行相关分析和聚类分析,结合单因子污染指数法和 Nemerow 综合污染指数法评价其安全性。 结果表明,铅、镉和铜的线性范围为 0~1.00 μg/mL,砷和汞的线性范围为 0~0.10 μg/mL,线性关系良好（r>0.998 6）, 检测限范围为 0.000 3~0.004 5 μg/mL,精密度实验 RSD 为 1.03%~4.39%,重复性实验 RSD     

Effects of copper and superoxide dismutase content of seminal plasma on buffalo semen characteristics

To investigate the effects of copper and superoxide dismutase (SOD) content of seminal plasma on buffalo semen characteristics, 54 semen samples collected from buffalo bulls by a bovine artificial vagina were used. Semen characteristics (motility, viability, morphology, concentration and volume) were recorded. Seminal plasma was harvested by centrifugation and kept frozen until analysis. Seminal plasma copper content was determined by atomic absorption procedure and SOD was measured by using a kit. The mean total copper value of seminal plasma was recorded as 2.51 +/- 0.04 mg kg(-1) (Mean +/- SEM) and the mean total SOD values was 39.02 +/- 0.81 IU mL(-1). To reduce the range of variability, the data were categorized according to their motility records in 3 groups of Excellent (Ex, >90% motile, n = 33), Good (Go, 80-89% motile, n = 15) and Moderate (Mo, < 79% motile, n = 6). The mean motility, viability, copper and SOD values in Ex group was recorded as 92.24 +/- 0.51%, 94.00 +/- 0.48%, 2.56 +/- 0.04 mg kg(-1) and 39.52 +/- 0.57 IU mL(-1), respectively. These values were 81.66 +/- 0.62%, 85.26 +/- 0.95%, 2.38 +/- 0.11 mg kg(-1) and 36.48 +/- 1.51 IU mL(-1) in Go group and 71.66 +/- 1.05%, 77.00 +/- 2.94%, 2.55 +/- 0.10 mg kg(-1) and 50.66 +/- 2.51 in Mo group, respectively. The mean copper value in Ex group was highly (r = 0.600) correlated with SOD and correlated with sperm motility (r = 0.372) and viability (r = 0.363), while, in Go group it was highly correlated (r = 0.945) with SOD and sperm viability (r = 0.652) and in Mo group it was correlated (r = 0.874) with semen volume only. The mean SOD values in Ex group was highly correlated with sperm motility (r = 0.492) and viability (r = 0.490) and mean copper values, in Go group, it was highly correlated whit sperm viability (r = 0.659) and mean copper values and in Mo group it had no significant correlations with semen parameters. These results suggest that copper and SOD content of the buffalo seminal plasma have an influence on the sperm motility and viability which are the most important factors in semen fertility.     

广西百色市芒果树根际土壤丛枝菌根真菌资源初探

为探明广西百色市芒果根际土壤丛枝菌根（arbuscular mycorrhizal, AM）真菌的分布情况,本研究对广西芒果主产区的芒果根际土壤及根系样本进行AM真菌分离,并比较不同施肥制度下芒果根际土壤的AM真菌种类和根系菌根侵染情况。采集5个主施有机肥的芒果园（OT）和5个主施化肥的芒果园（CT）根际土壤,采用湿筛倾析法分离土壤中的AM真菌孢子,通过富集和诱导培养纯化其中的AM真菌,进行分子和形态鉴定。采用墨水醋染色法对根系样本进行染色及内生真菌侵染率的测定。共分离出6种AM真菌,OT处理分离出无梗囊霉属（Acaulospora sp.）1种,近明球囊霉属（Claroideoglomus sp.）1种,类球囊霉属（Paraglomus sp.）1种;CT处理分离出无梗囊霉属2种,近明球囊霉属1种。2种施肥制度分离出的AM真菌种类较少,且分离出的AM真菌种类均较常见,并无特有种。根系染色发现,OT处理菌丝分布较多,AM真菌结构丰富,可明显观察到丛枝和泡囊结构,还发现有少量的深色有隔真菌（dark septate endophytes, DSE）;CT处理的菌丝相对较少,泡囊结构和丛枝也较少,DSE相对较多。方差分析结果显示,施肥类型、芒果品种和树龄对AM真菌的根外菌丝、泡囊结构以及孢子密度均有不同程度的影响,其中施用有机肥较化肥对AM真菌的根外菌丝和泡囊结构均有显著的促进作用。综上,本研究筛选所得菌种丰富了我国AM真菌菌种库,并为筛选果树高效AM真菌菌剂奠定物质基础,也为果园管理提供了新方向。     

Organic compounds increase the efficacy of famoxadone + cymoxanil in the control of bacterial leaf spot of lettuce

Bacterial leaf spot of lettuce, induced by Xanthomonas campestris pv. vitians, constitutes a major disease on commercial lettuce (Lactuca sativa) production in south Florida. Under greenhouse conditions, resorcinol, two antioxidants, and various sugar alcohols such as mannitol, were evaluated alone, and in combination with Tanos^® 50DF (25% a.i. of each component cymoxanil and famoxadone, E.I du Pont de Nemours and Company, Wilmington, DE) for control of bacterial leaf spot. Among the compounds evaluated, resorcinol (35–50% disease control) and mannitol (9–45%) were the most effective. In field trials, different mixtures containing propionic acid, mannitol, resorcinol, Tanos and or copper hydroxide (Kocide 3000^®, 46.1%, 30% copper equivalent) were evaluated for the control of bacterial leaf spot of lettuce. Field data support a moderate impact of Tanos in disease reduction. Both greenhouse and field data support a synergistic interaction between Tanos and the compounds including copper, in disease reduction. The mixture Tanos + resorcinol, or copper/resorcinol, Tanos + copper provided better or similar disease control than copper alone. No phytotoxicity was observed in our trials. In an integrated management program for bacterial leaf spot of lettuce, Tanos may be useful in tank mixes with these compounds and copper.