菌饼法筛选不同活性物对棉花黄萎病菌抑制效果研究

采用菌饼法测定了52种活性物对棉花黄萎病菌的抑制效果。试验结果由直观图片和典型的电镜扫描图片记载。筛选出了15种对棉花黄萎病菌抑制效果显著的活性物。     

4种药剂防治棉花黄萎病研究

大田试验结果表明,枯草芽孢杆菌、乙蒜素、恶霉灵、克萎星对棉花黄萎病都有一定的防治效果,尤其以活芽孢10亿个.g-1枯草芽孢杆菌可湿性粉剂防治效果显著。枯草芽孢杆菌叶面喷雾的最佳浓度为300～600倍液,防治效果可达54.35%～57.35%。     

硅酸盐菌对棉花枯黄萎病的拮抗作用及增产效果

 研究了硅酸盐细菌对棉花出苗、抗病性及产量的影响。试验表明,与卫福包衣及对照相比,用硅酸盐菌液拌种,对棉花枯黄萎病有明显的拮抗作用,增强了植株的抗逆性,可显著提高棉花产量。     

不同种衣剂对棉花黄萎病防治效果的研究

为研究不同包衣剂在棉花黄萎病防治中的效果,本试验用克百威、微肥分别与其它不同的杀菌剂组合,与对照共同组成5个处理,4次重复,随机区组设计,测定棉花的出苗率、裂铃吐絮期、有效结铃数、铃重、株高、病情指数和子棉产量等指标。各种药剂组合表现均好于对照,以克百威、多菌灵、甲基立枯磷和锌肥的组合为最好。在使用种衣剂防治棉花黄萎病时,建议推广10%克百威+10%多菌灵+5%甲基立枯磷+2.5%锌肥的组合。     

棉花区试黄萎病田间调查抽样技术研究

以棉花品种区域试验的田间病情调查为基础,研究了棉花黄萎病田间病情调查的抽样方法,分析了不同抽样技术的抽样误差。结果表明,棉花区试田间病情调查结果与人工病圃鉴定结果存在较大差异,不同的抽样规模和抽样方法对品种的抗病性评价有显著影响;棉花品种区域试验田间黄萎病病情调查,应该采取3个区组、全区逐行调查的方式进行;采用逐行计算病情指数的方法,能够通过统计方法剔除取样行间误差,提高品种间病情指数估计的精确度。     

利用植物疫苗及生长调节剂缩节胺控制棉花黄萎病

2008-2009年于棉花黄萎病重病田研究了植物疫苗渝峰99植保、激活蛋白、氨基寡糖素单独使用及与植物生长调节剂缩节胺混合使用对棉花黄萎病的防治效果,并选择激活蛋白和缩节胺混合施用研究了不同施药时间和施药次数对棉花黄萎病的防治效果。结果表明:渝峰99植保、激活蛋白、氨基寡糖素和缩节胺单独使用,以缩节胺防治效果最好(平均防效41.3%),其次是激活蛋白(平均防效36.7%)。3种植物疫苗和缩节胺混合使用均可不同程度地提高防治效果,渝峰99植保+缩节胺、激活蛋白+缩节胺、氨基寡糖素+缩节胺的平均防效分别为52.9%、52.2%、47.9%。在2个棉花品种上的试验结果均表明,于5月30日开始用药,每10天1次,连续用药3次,间隔20～30天再用药1～2次,对黄萎病的控制效果最好。     

枯草芽孢杆菌粉剂对棉花黄萎病防效初探

棉花黄萎病因缺乏有效药剂防治,一直是棉花种植业当中的一个难题。本试验表明,枯草芽孢杆菌在新疆农三师垦区对棉花黄萎病有比较明显的抑制作用,可显著提高棉花单产。     

江西棉区棉花黄萎病高效拮抗菌的筛选、鉴定和抗菌物质研究

 从江西棉区3个主产棉县采集17份棉株根际土样,从中分离纯化细菌396株,经实验室平板筛选和盆栽防病实验筛选出棉花黄萎病高效拮抗细菌3株,分别编号为C-02,C-22和C-32,它们对棉花黄萎病的相对防效分别为85.4%,79.4%和75.1%。其中菌株C-02经实验室生理生化特征测定和16SrDNA序列分析被鉴定为枯草芽孢杆菌,其胞外分泌抗菌物质被证实为蛋白质类。     

海岛棉GbHOX4基因荧光载体构建

 根据已公布的陆地棉GhHOX4序列设计适当引物,以海岛棉Giza75第一链cDNA为模板,用PCR方法,首次在海岛棉中克隆出GbHOX4的基因全长cDNA序列,用BamHI限制性内切酶酶切经改良带有绿色荧光蛋白标签的pBI121载体,构建了海岛棉GbHOX4基因荧光载体。     

大豆Gy1基因种子特异性表达载体的构建及在玉米中的转化

实验构建了2个大豆贮藏蛋白Gy1基因种子特异性表达载体,并将其分别转入玉米愈伤组织中。载体1以潮霉素为筛选标记,将Gy1基因片段插入到含有种子特异启动子的植物表达载体pCAMBIA1301-7αP上,得到种子特异性表达载体pCAMBIA1301-7αP-Gy1;载体2以BADH为筛选标记,将Gy1基因插入到带有耐盐基因BADH的植物表达载体pCAMBIA1301-BADH上,得到安全性无抗生素选择标记的种子特异性表达载体pCAMBI-A1301-sbeⅡb-Gy1。通过农杆菌介导法将其分别导入玉米自交系H99的愈伤组织中,共获得132株再生植株;经过PCR检测,初步证明获得了34株转基因阳性植株。     

Measurement of field resistance of potatoes to Verticillium wilt (Verticillium dahliae)

Summary Twenty seven clones were trialled in the Negev, Israel, in both the Spring and Autumn planting seasons of 1984 and 1985 and of these clones 18 were also grown in the Spring of 1986. All clones were grown in fumigated soil (designated, Control) which was subsequently kept as disease-free as possible and in soil previously infested withVerticillium dahliae, the causal agent of Verticillium wilt and a component of the potato early-dying syndrome. The clones differed in maturity and showed a range of symptoms in the field. A true assessment of resistance or susceptibility could not be obtained unless allowance was made for the effects of maturity. Only a few clones showed significant resistance. The importance of the results, in relation to screening breeders' clones for resistance, is discussed.     

棉田复种芥菜对土壤中大丽轮枝菌和黄萎病的影响

为明确棉田复种芥菜(Brassica juncea)对黄萎病及土壤中大丽轮枝菌(Verticillium dahliae Kleb.)的影响,通过定量检测土壤中V.dahliae微菌核数量,监测棉花黄萎病发生程度,研究棉田复种芥菜对土壤中V.dahliae微菌核数量季节性动态的影响和棉花黄萎病的防治效果.试验设棉花单作...     

向日葵黄萎病菌营养亲和性及致病力分化

为进一步研究向日葵黄萎病病原菌的变异规律及不同菌株致病力差异,本研究以采自于黑龙江、内蒙古东部和西部、河北、陕西、宁夏、新疆等向日葵黄萎病发生严重的地块,并经分离纯化后得到的120株菌株为材料,开展了菌株间营养亲和性、致病力分化研究。结果表明：利用硝酸盐营养缺陷型突变体( nit )技术可将120株菌株分为3个亲和群（VCGs）,3个亲和群分别有89株、13株、7株,此外,还有11株未能鉴定出亲和群。通过对3个鉴别寄主的致病力测定,120株菌株可分为3个致病类型,强致病力（I）占7.3%,中等致病力（II）占52.7%,弱致病力（III）占40%,菌株致病力存在明显的差异。研究同时表明菌株间营养亲和性与地理位置没有明显的相关性,但与致病性类型具有一定的相关性。       

A review of the pathogenicity mechanism of Verticillium dahliae in cotton

Verticillium wilt, caused by the notorious fungal pathogen Verticillium dahliae, is one of the main limiting factors for cotton production. Due to the stable dormant structure microsclerotia, long-term variability and co-evolution with host plant, its pathogenicity mechanism is very complicated, and the interaction mechanism between pathogen and host plant is also unclear. So identification and functional analysis of the genes involved in the pathogenicity or virulence of this fungus will benefi...     

茶树咖啡因合成酶基因RNA干涉表达载体构建

咖啡因合成酶（TCS）是茶树咖啡因生物合成途径中的一个关键酶,催化7-甲基黄嘌呤转变为可可碱和可可碱转变为咖啡因。抑制TCS基因表达是培育低咖啡因茶树的最有效途径。用RT-PCR方法扩增茶树TCS基因的两个cDNA片段,并克隆入T-载体中。干涉载体和TCS基因片段的T克隆经限制性内切酶两次双酶切与连接,将两个TCS基因片段分别反向重复插入到干涉载体pFGC5941,构建了TCS基因的RNA干涉载体,分别命名为pFGC5941-TCS02和pFGC5941-TCS03。经PCR和DNA测序获得验证。TCS基因RNA干涉载体的构建为培育低咖啡因茶树奠定了基础。     

Evaluation of chemical disinfestants in reducing Verticillium dahliae conidia in irrigation water

Irrigation water disinfestation is an unexplored option for reducing Verticillium dahliae inoculum in water and consequently for more efficiently managing Verticillium wilts in Andalusia. We assessed Suppressive Efficacy (SE; water was infested and subsequently treated) and Preventive Efficacy (PE; previously treated water was subsequently inoculated) of OX-VIRIN^®, OX-AGUA AL 25^® and Deccoklor^® in reducing water infestations by V. dahliae conidia. Five concentrations of each disinfestant, the lowest three being recommended by the manufacturer, were tested in vitro against six V. dahliae isolates. Validation assays were carried out in experiments under natural environmental conditions in spring. The four highest concentrations of OX-VIRIN^® (0.8–51.2 mL L⁻¹), the three highest of OX-AGUA AL 25^® (46.4–417.5 μL L⁻¹) and the two highest of Deccoklor^® (0.375 and 3.75 mL L⁻¹), showed an in vitro-efficacy (SE and PE) of 96.2, 80.0 and 100.0% after 30, 5 to 30 and 15 days respectively. Therefore, recommended concentrations for OX-VIRIN^® and OX-AGUA AL 25^® showed a greater in vitro-effectiveness than those recommended for Deccoklor^®. Assays in natural environmental conditions proved that OX-VIRIN^® at the recommended concentration of 3.2-mL L⁻¹, applied every 28 days to water, was the most effective treatment (SE and PE), with a 100% reduction of the average relative viability after 56 days. Other chemical treatments showing high in vitro-efficacy, such as OX-VIRIN^® at 0.8 mL L⁻¹ and OX-AGUA AL 25^® at 46.4 μL L⁻¹ showed an SE of 99.9% after 14 and 28 days when applied every 28 and 14 days, respectively. However, PE of OX-AGUA AL 25^® at 46.4 μL L⁻¹ was only 59 and 38% after 28 and 14 days respectively, depending on the experiment.     

Trichoderma asperellum is effective for biocontrol of Verticillium wilt in olive caused by the defoliating pathotype of Verticillium dahliae

Verticillium wilt caused by a highly virulent, defoliating (D) pathotype of Verticillium dahliae is threatening olive production in Spain and other Mediterranean countries. This disease must be managed by an integrated strategy, in which biocontrol agents can play an important role. We have investigated the potential of Trichoderma asperellum strains for antagonism against V. dahliae and suppression of Verticillium wilt of olive caused by the D pathotype. First, we tested the antagonistic potential of T. asperellum strains Bt2, Bt3 and T25 against six V. dahliae isolates, four of the D and two of the nondefoliating (ND) pathotypes, in different in vitro assays. All T. asperellum strains overgrew the colonies of all V. dahliae isolates to a similar extent. However, extracellular compounds from strains Bt3 and T25 showed higher anti-V. dahliae activities than those of Bt2 in membrane assays. Also, growth of Bt2 was reduced by ND V. dahliae whereas that of Bt3 and T25 was not affected by V. dahliae-secreted compounds. In planta assays using strains Bt3 and T25, and ’Picual’ olive plants, showed that the two T. asperellum strains significantly reduced the severity of symptoms and the standardized area under the disease progress curve caused by highly virulent D V. dahliae, but not the final disease incidence. Strain T25 significantly increased growth of ‘Picual’ plants and displayed higher ability for colonizing the olive rhizosphere and establishing endophytic infection in olive roots than Bt3.     

不同棉区黄萎病菌对4种常用杀菌剂的敏感性测定

采用菌落生长速率测定法,将分离自三大棉区的棉花黄萎病菌菌株对福美双、甲基硫菌灵、百菌清和多菌灵的敏感性进行测定。结果表明,不同来源的黄萎病菌菌株对多菌灵敏感性最高,百菌清次之,福美双和甲基硫菌灵敏感性较低。虽然三大棉区不同菌株对杀菌剂的敏感性有所差异,但对多菌灵均有较高的敏感性。