Fusarium mangiferae侵染对芒果矿质元素含量的影响

为探讨芒果感染畸形病过程中顶芽内矿质元素含量的变化规律,以凯特芒为试验材料,测定了接种病菌Fusarium mangiferae后顶芽内矿质元素含量的变化。结果表明,F.mangiferae的传染能够引起芒果体内矿质元素含量发生改变。其中,氮、钾、铁和锰的含量随着接种时间的延长不断上升,且上升幅度较大,其次是磷、镁、硼和锌,铜和硫的含量变化不明显,钙随着接种时间的延长其含量不断降低。     

3种瓜类枯萎病菌Fusarium oxysporum的分子检测

 Fusarium oxysporum is one of the most important phytopathogens and cause Fusarium wilt disease in cucumber, watermelon and melon, etc.In this study, a pair of species-specific primers Fc-1 and Fc-2 was synthesized based on differences in internal transcribed spacer sequences of Fusarium genus.With the primers, a specific 315 bp PCR product was amplified from five F.oxysporum isolates isolated from cucumber, watermelon and melon, infected cucumber and watermelon tissues, while no product was obtained from other fourteen fungi, healthy cucumber and watermelon tissues.The detection sensitivity is 100 fg for genomic DNA of F.oxysporum and 1 000 spores/g soil for the soil pathogens.In contrast, the nested PCR with two pairs of primers(ITS1/ITS4 and Fc-1/Fc-2) increased the sensitivity by 100-fold.In addition, one-step PCR could also detect F.oxysporum in symptomless cucumber root of 7 dpi(days post inoculation) and in infected cucumber and watermelon tissues at the early stage of disease development.Therefore, the developed PCR-based method enabled rapid, sensitive and reliable detection of F.oxysporum.It also provides the detection method for early monitoring and diagnosis of the pathogen as well as the plant disease management guidance.     

Fusarium boothii特异性PCR检测方法的建立与应用

根据报道的Fusariumspp.的reductase-like基因序列,设计合成了1对用于Fusarium boothii的特异性检测引物F-Fg/R-Fg。利用该对引物对包括F.boothii在内的35株镰刀菌的基因组DNA进行了扩增。结果表明:该引物特异性强,仅从F.boothii基因组DNA中扩增出300bp左右的特异性条带,其他参照菌株及阴性对照均无任何条带;灵敏度验证结果表明,该检测法可以检测出50pg F.boothii基因组DNA。     

由烟草镰刀菌Fusarium tabacinum引起的向日葵新病害

1984年9月在意大利中部的佩鲁贾附近地区,在夏季种植的向日葵的不同栽培品种上发现了一种新的病害。其症状为感病植株的茎出现灰白变色,且很易碾碎;纵向茎剖面呈散射状,根茎区到地面以上30～40cm 处的髓部呈浅桃红色,显微镜下观察可看到髓部组织中有已有消解的透明菌丝存在。从感病的向日葵茎杆上分离到的真菌在 PDA 培养基上产生淡黄色或橙红色菌落,少有或没有气生菌丝体。分生孢子的形状随培养基的成份和培养时间的不同而不同,通常为圆形、椭圆形或微     

马铃薯干腐病优势病原菌Fusarium sambucinum 分子检测技术的建立

马铃薯干腐病是马铃薯最重要的贮藏期病害之一,现已成为马铃薯贮藏期烂窖的重要原因。实现病原菌的快速检测对病害诊断和科学防控具有重要的实践意义。本研究基于镰刀菌翻译延伸因子序列设计了一对检测接骨木镰刀菌Fusarium sambucinum的特异引物Fs-F/Fs-R。该特异引物可从接骨木镰刀菌中获得309bp的特异性扩增片段,而其他种类镰刀菌及马铃薯重要病害病原菌中均无此片段,说明该引物具有专一性。该体系的灵敏度检测结果表明,最低能检测到的接骨木镰刀菌基因组DNA浓度为70pg/μL。该引物也适用于发病马铃薯块茎中接骨木镰刀菌的快速检测。     

Fusarium boothii的特异性PCR检测方法的建立与应用

为了研究甘薯不同生育时期感染甘薯病毒病（SPVD）对甘薯产量的影响,并建立产量损失估计模型,以‘郑薯20’和‘徐薯25’两个甘薯品种为试验材料,分4个时间嫁接感染 SPVD。试验结果表明,感染 SPVD 的甘薯病情指数随着嫁接时间推迟而降低,叶绿素含量随嫁接时间推迟而逐渐提高,单株鲜重和干重随着嫁接时间的推迟逐渐增加。根据2012年试验结果,建立了病情指数（X）与产量损失率（Y）之间的关系模型：Y ＝0．7276X ＋23．279,R2＝0．8845,并利用2013年试验数据对模型进行了验证。     

尖镰孢菌(Fusarium oxysporum)的快速分子检测

 由尖镰孢菌(Fusarium oxysporum Schlecht.)引起的大豆枯萎病是危害大豆生产的主要土传病害^［1］。该菌在土壤和病残体上均可长期生存造成危害。快速准确地在发病初期植株和带病土壤中进行鉴定和检测对防治该病害至关重要。     

甘肃省马铃薯枯萎病（Fusarium avenaceum）鉴定及其病原生物学特性

对甘肃省马铃薯枯萎病菌进行了分离、鉴定及培养特性的研究。结果表明,该病原菌大型分生孢子镰刀形,无色,多细胞,大小为（12.5~30）μm×（2.5~5）μm;小型分生孢子数量较多,无色,卵圆形或椭圆形,大小为（4.70~12.94）μm×（1.76~2.35）μm;ITS序列分析表明,病原菌与Fusarium avenaceum（JN6317483）亲缘关系最近,相似性达到100%,结合形态特征鉴定该病原菌为燕麦镰刀菌(Fusarium avenaceum)。该病原菌在5~40 ℃范围内均可生长,最适温度为20 ℃;供试的碳、氮源中,果糖和亮氨酸对该菌菌丝生长有显著的促进作用（P<0.05）,而显著抑制菌丝生长的是氯醛糖和碳酸铵（P<0.05）;不同类型培养基中,燕麦片培养基对菌丝生长有显著促进作用（P<0.05）。     

杧果与Fusarium mangiferae在转录水平上的互作机制

基于Illumina HiSeq~(TM)2000平台,对健康与感病杧果顶芽的转录组进行测序,采用BLAST软件将获得的Unigene与NCBI-nr、Swiss-Prot、KEGG和COG数据库进行比对,根据基因功能注释后分析杧果病健组织的差异表达基因(DEGs),并对DEGs进行GO和Pathway富集分析。结果表明:2个样品共获得119 815条Unigene,N50为1 546 bp,平均片段长度为880 bp;鉴定了29 878个DEGs,对随机挑选的11个差异表达基因进行了qRT-PCR验证,结果与转录组一致。以corrected P-value≤0.05为阈值的代谢途径有22条,其中大多数代谢途径与植物的抗逆响应密切相关;153个DEGs参与了淀粉和蔗糖代谢途径,DEGs主要是编码糖类异构酶、水解酶和转移酶等,参与葡萄糖水解、细胞碳水化合物、丙酮酸盐和核苷酸代谢等生物进程;在抗氧化生物过程中,编码活性氧代谢相关酶且log_2Ratio10或-10以上的DEGs有20个,14个属上调表达,表明活性氧代谢在杧果与病原互作过程中起到重要的调解作用;F.mangiferae侵染杧果后,以log_2Ratio10或-10为筛选条件,共获得酚类代谢相关差异表达基因53个,其中40个DEGs上调表达,推测杧果可能是通过合成加固细胞壁的木质素或生成抑菌作用的酚类化合物来提高对病原菌的抵抗能力;杧果与F.mangiferae互作过程中,钙信号传导、SA信号途径和丝裂原活化蛋白信号传导途径相关基因表达下调,造成了下游植物抗病基因RPM1的表达受到抑制,这可能是杧果畸形病的主要成因之一。     

南方镰孢Fusarium meridionale特异性PCR检测方法的建立与应用

为建立快速、稳定的南方镰孢Fusarium meridionale特异性检测方法,对已报道的镰孢属reductase-like基因部分序列进行比对分析,寻找特异性SNP位点,设计出特异性检测引物F-Fm/R-Fm3。利用该引物对包括南方镰孢在内的30株镰孢的基因组DNA进行PCR扩增。结果显示仅在7株南方镰孢中均扩增出400 bp左右的特异性条带。PCR灵敏度试验结果表明该方法的检测灵敏度达到500 pg基因组DNA。     

甜瓜枯萎病菌（Fusarium oxysporum）专化型的初步研究

本研究获得的甜瓜枯萎病病株9株分离物（南通市6株,新疆3株）,经PDA培养性状发现,其在菌落颜色、质地和生长速率方面存在差异,大型分生孢子的大小为(19.54～41.11)μm×(4.90～8.16)μm,与西瓜枯萎病菌的大型分生孢子有较大差异。胚根法成株期致病性测定结果发现,本研究的甜瓜枯萎病菌分离物在不同鉴别寄主和鉴别品种上致病性存在专化型和生理小种方面的差异,但分离物中不存在西瓜枯萎病菌。利用核糖体转录间隔区保守序列设计引物,PCR检测也证明本研究甜瓜枯萎病菌不同分离物中不存在西瓜枯萎病菌。     

Mitigation of vanillic acid-promoted faba bean Fusarium wilt by faba bean–wheat intercropping

Long-term continuous monocropping of faba beans increases the incidence of faba bean wilt, while faba bean–wheat intercropping can effectively control it. This study aimed to understand the underlying mechanism of faba bean–wheat intercropping for the control of Fusarium oxysporum and vanillic acid (VA)-promoted occurrence of faba bean wilt. The occurrence of faba bean wilt was investigated among the monocropped and intercropped plants of faba beans in a field experiment. The contents and types of phenolic acids were examined in the rhizosphere soil. Monocropped and intercropped faba beans were examined under the dual stress of F. oxysporum and different concentrations of VA (0, 50, 100, 200 mg/L) to understand the alleviating mechanism of faba bean–wheat intercropping. Exogenous addition of high concentrations of VA significantly inhibited the growth and reproduction of F. oxysporum, but under the dual stress of F. oxysporum and different concentrations of VA, it significantly inhibited the defence enzymes of faba bean roots, stems, and leaves, and rhizosphere soil enzymes. Interestingly, faba bean–wheat intercropping alleviated VA stress and thereby the incidence and disease index of faba bean Fusarium wilt by improving plant resistance and soil enzyme activity. The dual stress of F. oxysporum and VA promotes the occurrence of Fusarium wilt by damaging the defence system of the faba bean root system and rhizosphere soil environment. However, faba bean–wheat intercropping effectively alleviates the autotoxicity of VA by improving the physiological and biochemical resistance of faba beans and soil enzyme activities, and thus controls the occurrence of Fusarium wilt.     

半夏防御酶系对Fusarium oxysporum和Phytophthora parasitica侵染的动态反应

尖孢镰刀菌(Fusarium oxysporum Schlecht)和寄生疫霉(Phytophthora parasitica Dastur)分别为引起半夏块茎腐烂病和疫病的病原,为探索半夏在受到这2种病原侵染时的生理生化反应,采用室内盆栽方法,研究超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)5种寄主防御酶活性在块茎腐烂病和疫病发生过程中的变化趋势。结果表明,半夏在接种2种病原菌后,分别于第2天和第3天出现发病症状,第5天病情指数分别高达70.3、70.6;SOD活性都于接种后第1天达到高峰,POD活性都于接种后第3天达到高峰,CAT活性都于接种后第2天达到高峰,PAL活性分别于接种后第2天和第3天达到高峰,而PPO活性分别于接种后第3天和第4天有小幅上升。初步表明,在寄主显症之前或发病初期酶活性达到高峰的SOD、POD、CAT、PAL在半夏抗病生理机制中起着重要作用,在半夏抗病种质筛选时需要重点关注。     

基于环介导等温扩增技术快速诊断由Fusarium andiyazi引起的水稻恶苗病

水稻恶苗病是水稻上的重要病害,在我国各水稻主要种植区均有发生,造成水稻产量的严重损失。Fusarium andiyazi是近年来国外报道的水稻恶苗病的病原菌之一,本研究基于环介导等温扩增技术(loop-mediated isothermal amplification,LAM P),以F.andiyazi的TAT(trichothecene 3-O-acetyltransferase)基因为靶标设计并筛选出一套灵敏、特异的LAM P引物,建立了可快速诊断该病菌所引起的水稻恶苗病的LAMP检测技术。在等温条件下(64℃)只需进行核酸扩增反应80 min,反应前向体系中加入了金属离子指示剂HNB(羟基萘酚蓝),反应后即可肉眼观察反应产物颜色变化判断检测结果,阳性反应呈天蓝色,阴性呈紫色。该TAT-Fan-LAMP技术的最低检测灵敏度为100 pg·μL~(-1)。应用该技术成功地对南京江宁和镇江句容田间采集的由F.andiyazi引起的水稻恶苗病进行快速诊断。该LAMP检测技术的建立为F.andiyazi引起的水稻恶苗病的诊断提供了简便快速的新技术。     

尖孢镰孢(Fusarium oxysporum)硝酸盐营养突变株及其营养体亲和性

从荸荠、棉花、西瓜、黄瓜、胡瓜、大豆、花生等12种寄主作物上获得尖孢镰孢(F—usarium oxysporum)菌株20个,已知15个菌株分属于6个专化型。所有20个菌株在含有氯酸盐的培养基上产生抗氯酸盐的突变体,其突变体在以硝酸盐作为氮源的培养基上表现为无气生菌丝生长,即不能利用硝酸盐的突变株(nit),共获得nit突变株181个。同一专化型的nit突变株之间在以硝酸盐为氮源的培养基上配对时,在菌丝接触处可产生互补作用,即营养体亲和性,表现为旺盛气生菌丝生长。不同专化型的nit突变株之间则不能互补产生异核体而表现为非亲和性仍为突变型生长。每个菌株均获得能产生互补作用的nit突变株。根据营养体亲和性反应,20个菌株归入13个营养体亲和群(VCG),并显示出VCGs与菌株专化型之间的相关性。nit突变株在一般条件下是稳定的,而且某些nit株的亲和能力特强。     

尖孢镰孢(Fusarium oxysporum)硝酸盐营养突变株及其营养体亲和性

 从荸荠、棉花、西瓜、黄瓜、胡瓜、大豆、花生等12种寄主作物上获得尖孢镰孢(F-usarium oxysporum)菌株20个,已知15个菌株分属于6个专化型。所有20个菌株在含有氯酸盐的培养基上产生抗氯酸盐的突变体,其突变体在以硝酸盐作为氮源的培养基上表现为无气生菌丝生长,即不能利用硝酸盐的突变株(nit),共获得nit突变株181个。同一专化型的nit突变株之间在以硝酸盐为氮源的培养基上配对时,在菌丝接触处可产生互补作用,即营养体亲和性,表现为旺盛气生菌丝生长。不同专化型的nit突变株之间则不能互补产生异核体而表现为非亲和性仍为突变型生长。每个菌株均获得能产生互补作用的nit突变株。根据营养体亲和性反应,20个菌株归入13个营养体亲和群(VCG),并显示出VCGs与菌株专化型之间的相关性。nit突变株在一般条件下是稳定的,而且某些nit株的亲和能力特强。     

Immunocytochemical localization of β-1,3-glucanase and chitinase in Fusarium culmorum -infected wheat spikes

Two antisera raised against acidic β-1,3-glucanase and acidic chitinase from tobacco were used to investigate the subcellular localization of the two enzymes in Fusarium culmorum -infected wheat spike by means of the immunogold labelling technique. The studies demonstrated that the distribution of β-1, 3-glucanase and chitinase were very similar in the uninoculated healthy and infected wheat spikes. The enzymes were localized mainly in the cell walls of different tissues including the lemma, ovary and rachis of the wheat spike, while the cytoplasm and organelles of cells in these tissues showed almost no labelling. However, the accumulation of β-1,3-glucanase and chitinase in the infected wheat spikes differed distinctly between resistant and susceptible wheat cultivars. The labelling densities for the two enzymes in the infected lemma, ovary and rachis of the susceptible cultivar Agent increased only slightly as compared to the corresponding uninoculated healthy tissues, whereas higher labelling densities of β-1,3-glucanase and chitinase were found in the infected tissues of wheat spikes from the resistant cultivar Arina compared to the corresponding uninoculated healthy tissues. Furthermore, the labelling of β-1,3-glucanase and chitinase also occurred over the cell walls of the hyphae in the infected wheat spike, but not over the hyphal cytoplasm. In addition, labelling for the two enzymes was often detected over the cell wall appositions and the electron-dense material located between the host cell and the hyphal cell in the infected tissues of the resistant wheat cultivar. The findings reported in the present study indicate that β-1,3-glucanase and chitinase accumulation in the F. culmorum -infected wheat spike may be involved in resistance to pathogen spread in the host tissue.     

Mykotoxinbildung während der Infektion der Weizenähre durch den pathogenen Pilz Fusarium graminearum

Fusarium graminearum is one of the most destructive pathogens of cereals and a threat to food and feed production worldwide. Infection especially of wheat leads to yield losses and mycotoxin contamination. Deoxynivalenol is a hazardous mycotoxin inhibiting the biosynthesis of proteins. Its production by the fungus is a prerequisite for the colonization of the wheat spike. Combining molecular genetics with bioimaging techniques allows a fascinating insight into the pathobiology of this cereal pathogen.     

麦秸掩埋还田对赤霉菌(Fusarium graminearum Sehw.)存活率和水稻带菌的影响

In order to determine the influence of different straw concentrated buried depth to survival rate of Fusarium graminearum and carrier rate of rice, six treatments including four buried depths (5 cm, 20 cm, 35 cm, 50 cm) and ck (straw mulched and rotary tillage returned), were set up from July to November in 2011. The research turned out that the flooded time and returning depths significantly affected the survival days and survival rate of F. graminearum. In flooded condition, straw with F. graminearum were centralize-buried. The survival time of the F. graminearum was 18 days at the most. The straw with Gibberella return into soil could cause the soil contaminated. Straw mulching, rotary tillage returning and 5 cm buried will increased the cross-infection phenomenon of F. graminearum in wheat and rice, while buried over 20cm, the colonies were reduced and the rice won’t be infected with F. graminearum     

Efficacy and dose–response relationship in biocontrol of Fusarium disease in maize by Streptomyces spp.

Two isolates of Streptomyces spp. DAUFPE 11470 and DAUFPE 14632 were evaluated to determine the antagonist–pathogen inoculum concentration relationship under greenhouse conditions. Pathogen and antagonist concentration, significantly (P < 0.05) affected development of Fusarium disease in maize with a significant interaction between pathogen and antagonist concentration. Dose–response relationship also differed significantly (P < 0.05) between the two isolates, but both isolates demonstrated effective control of Fusarium disease, regardless of pathogen concentration. The isolate DAUFPE 11470 provided the most effective control. The lowest value for disease incidence occurred at low pathogen (10³ chlamydospore g⁻¹ soil) and high antagonist concentration (10⁶ cfu ml⁻¹) for both isolates. The disease incidence for control plants ranged from 19% to 76%. However, in relation to control the lowest disease reduction occurred at low pathogen (10³ chlamydospore g⁻¹ soil) and high antagonist concentrations (10⁶ cfu ml⁻¹). These reductions were 10.6% and 13% for DAUFPE 14632 and DAUFPE 11470, respectively. The highest disease reductions, in relation to control plants, occurred at high pathogen (10⁶ chlamydospore g⁻¹ soil) and antagonist (10⁶ cfu ml⁻¹) concentrations for both isolates. These values were 55% and 62.2% for DAUFPE 14632 and DAUFPE 11470, respectively. The chlamydospore germination of Fusarium moniliforme was affected by glucose addition, antagonist isolates and type of inoculum. The lowest chlamydospore germination was observed with bacterial suspensions of the isolates, for all glucose additions. The results suggested that both Streptomyces spp. isolates were effective at different doses as biocontrol agents against F. moniliforme. Also, there was evidence for at least two mechanisms of biocontrol and that apparently, both isolates showed the same mechanisms of biocontrol action related to production of bioactive compounds and competition for carbon. Further studies will be developed to improve the level and effectiveness of control by these isolates.