不同微肥叶面处理对烟草病害发生的影响

为明确微肥施用对烟草病害的防控效果,在重庆市黔江区水市烟草基地开展了田间小区试验,调查不同处理对烟草病害的影响.结果表明:团棵期和旺长期2次叶面补充微量元素对烟草普通花叶病、赤星病、野火病和青枯病均有一定控制效果.其中,叶面补充锌元素对控制烟草普通花叶病、野火病的效果较好,叶面补充硼元素对烟草赤星病、野火病和青枯病的防控效果较好.因此,在今后实际生产中,可结合烟草生长和病害防治关键期,通过叶面喷雾或灌根的方法分时期、分次、适时、适量补充硼肥和锌肥,同时,结合药剂复配来实现农药的减量增效以及减少防治投入,这对于烟株保健、控制化学投入品、延缓病害进程均有重要意义.     

烤烟K326品种病虫害发生种类及动态研究

为了明确K326的病虫害发生种类和流行规律,通过在重庆武隆白马基地建立病虫害监测点,结合烟草病虫害系统调查方法,对武隆白马烟区的主要有害生物进行了调查,初步掌握了武隆白马烟区K326品种的病虫害发生动态.结果表明,地下害虫、野蛞蝓等主要在烟草生长早期为害,在烟苗移栽过程为害较为严重,连续的阴雨天气会导致为害进一步加重;打顶期过后,底部烟叶出现了气候斑点病,通过8月20日调查显示,气候斑点病的发病率维持在2.25%.调查发现,K326品种对烟草根茎病害具有一定的抗性,而对后期的叶部病害如赤星病、野火病则属于感病品种.目前,白云烟区已经零星发生赤星病、野火病,发病率在5～8%左右.鉴于烟草生长后期降温、降雨天气较多,容易造成以赤星病、野火病为主的叶部病害的大面积爆发,因此,建议进行叶部病害防控全程植保专业化服务,减少后期叶部病害的发生、为害.保证武隆白马基地的K326品种的产量和质量.     

烟草番茄斑萎病毒病防治措施

烟草番茄斑萎病毒病由番茄斑萎病毒引起,是世界农业生产上一大病害,在我国局部烟区为害严重,被认为是我国烟草生产的重要潜在病害之一。结合烟叶生产,介绍烟草番茄斑萎病毒病的发生特点和防治技术,为生产中烟草番茄斑病毒病的防控提供依据。     

一种新的90 kD胞外蛋白激发子诱导烟草系统获得抗性研究

 就棉疫病菌(Phytophthora boehmeriae Saw.)培养滤液中提纯获得的90 kD胞外蛋白激发子诱发烟草系统获得抗性进行了研究。以10 nmol/L激发子溶液注射处理Samsun NN烟草叶片24 h后,在处理叶片及其上、下各2片叶片接种TMV,结果是处理叶及其上、下各2片叶片上的枯斑数显著少于对照,诱抗防效达40.9%~53.1%;接种TMV7d后处理叶片的枯斑平均直径为1.23mm,显著小于对照叶片上的枯斑直径2.97mm,但是处理叶片的上、下叶片上的枯斑平均直径与对照没有显著差别。以10 nmol/L激发子溶液注射处理Samsun NN烟草叶片分别立即接种或于1、2、4、7、15 d接种TMV,结果证明该激发子诱导烟草对TMV的抗性以处理后第1d至第4 d接种为较好,防效达30.2%~5 0.4%;处理后立即接种和第7d接种TMV诱抗防效仅4%左右,处理叶片上的枯斑数与对照没有显著差别,表明较强的诱导抗性可持续时间<7d。用不同浓度激发子处理烟叶,所测定的0.5~100 nmol/L各浓度均可显著地诱发烟草对TMV产生获得抗性,诱导抗性效果为34.9%~5 8.2%,诱导抗性效果随浓度的降低呈下降趋势。以10 nmol/L激发子溶液注射处理W38烟草叶片,2 d后分别注射接种烟草野火病菌(Pseudomonas syringae pv.tabaci)菌液或喷雾接种烟草赤星病菌(Alternaria alternata)分生孢子,结果是,注射接种烟草野火病菌5d后处理叶片及其上、下叶片上的野火病病斑均显著小于对照;处理叶片上的赤星病病斑数及病斑面积明显小于对照,表明该激发子可诱导烟草对野火病和赤星病产生抗性。上述结果表明,90kD蛋白激发子诱导烟草产生的获得抗性是一种典型的系统获得抗性,该系统获得抗性对病原菌具广谱抗性。     

烟草主要叶斑病害的诊断及防治技术

随着烟草种植面积的不断扩大 ,连作烟田的增多 ,连作年限的延长 ,耕作栽培制度及烟草品种的变化 ,烟草病害种类也随之增多 ,危害不断加重。在各类病害中 ,烟草叶斑病成为了烟草生产威胁最大的一类病害。烟草赤星病、烟草野火病在中国各烟区为害逐年加重 ,局部地域常出现毁灭性为害 ,给烟叶生产带来重大损失。鉴于叶斑病危害的严重性 ,现对烟草生长期容易混淆的主要叶斑病害的识别特征及防治技术加以总结。1　烟草赤星病烟草赤星病俗称“红斑”、“恨虎眼” ,该病是烟叶成熟期的病害 ,在烟株打顶后 ,叶片进入成熟阶段开始发病 ,条件适宜病情…     

烟草大田期病害配方施药试验

鉴于云南烟区大田期烟草病害混合发生日趋严重,单一农药品种防效较差的状况,作者选用云南烟区几个常用农药品种,根据田间病害组成相和农药理化性质,提出了烟草配方施药方案,并进行了田间小区试验和同田对比试验。小区试验结果表明:909—B1混配剂对烟草赤星病平均防效为71.1％,对烟草蛙眼病、炭疽病、角斑病等叶斑类病害的平均防效为81.3％,对烟草野火病平均防效为80.9％。同田对比试验与小区试验结果基本相同,表明配方施药对真菌、细菌病害有较好的防治效果,尤其是909—B1明显优于其他供试农药品种。     

2011年昆明市烟草主要病害发生特点

通过对昆明市烟草病虫害预测预报网络中烟草病毒病、黑胫病、赤星病、炭疽病、白粉病、野火病的发生观测研究,浅析了2011年昆明市6种烟草病害的发生趋势和发生特点。结果表明：2011年昆明市烟草赤星病、炭疽病、白粉病、野火病的发生较为轻微。     

β-氨基丁酸诱导烟草产生PR蛋白及对TMV的抑制作用

 本文研究了β-氨基丁酸(BABA)诱导系统侵染寄主烟草NC89产生PR蛋白及其对TMV的抑制作用。用5mmol/LBABA对抗性烟和非抗性烟进行叶面喷施处理均可以抑制烟草叶片中TMV的产生,平均抑制率分别达到59%和49%。BABA和SA处理均可以诱导2种烟草叶片中PR1、PR2和PR5基因的表达,其中对PR1的诱导作用相对较强。分别用BABA和SA处理非抗性烟草,在处理后的不同时间内2种药剂对PR1基因的诱导规律基本相同。用BABA和SA分别预处理非抗性烟草2d后接种TMV,2种药剂对烟草叶片中PR1基因的影响是完全不同的,其中,BABA处理后接种TMV抑制PR1基因的表达,在接种后第72h已经检测不到PR1基因的存在,SA处理后接种TMV对PR1基因的影响呈现弱-强-弱的变化趋势,在接种后第24hPR1的表达量达到最强,以后逐渐减弱。试验结果表明:BABA能够提高非抗性烟草对TMV的抗性,但是BABA诱导烟草产生抗TMV的作用机制可能是一种不同于目前普遍公认的SA的作用机制。     

烟草野火病及其防治

烟草野火病属细菌性病害。云南主要烟区普遍发生,严重影响着烟叶质量,成为我省烤烟上主要病害之一。一、病害症状野火病在烤烟苗期和生长期均可出现。开始叶上呈黑褐色水渍小斑,圆形,病斑周围有明显的黄色晕圈,几个病斑可愈合形成不规则状斑块,有的产生轮纹,干燥时...     

赤星菌弱毒株孢子制剂PCF1对烟草赤星病的控制作用

本文研究了赤星菌(Alternaria alternata)弱毒株TBA16的灭活孢子制剂PCF1对烟草抗赤星病的诱导作用,及在田间控制赤星病的效果和对烟叶产量、品质等性状的影响。在温室内幼苗上,PCF1可明显诱导烟草对赤星病的系统抗性,抗性诱导效应为57％—89％。在山东5个主要产烟县进行的田间试验表明,PCF1有3种作用:①可以明显控制赤星病的发生程度,效果与用作对比的化学农药菌核净相当或略低,在烟草生长后期防治效果可达76％;②增强烟株生长和叶片扩展能力,使烟叶(烘烤后)产量提高7％—38％;③明显改善烟叶内在品质、增加上中等烟叶的比例,使产值提高17％。     

Activation of tomato plant defence responses against bacterial wilt caused by Ralstonia solanacearum using DL-3-aminobutyric acid (BABA)

In this study, we investigated the ability of DL-3-aminobutyric acid (BABA) to protect tomato against bacterial wilt caused by Ralstonia solanacearum. This was combined with studies of accumulation of total phenolic compounds, free and total salicylic acid (SA), and activity of enzymes related to plant defence, i.e., polyphenol oxidase (PPO) and catalase (CAT). Under greenhouse conditions, tomato plants pre-treated by soil drenching with BABA profoundly reduced disease severity of bacterial wilt compared to plants receiving a soil drench with water. Thus, BABA reduced leaf wilting index by 75.3 % and vascular browning index by 69.9 %, without any in vitro inhibitory activity on the pathogen. BABA treatment significantly reduced the population of R. solanacearum in stems of tomato plants and additionally also significantly increased both fresh and dry weight of roots and shoots of tomato plants compared with the inoculated control. Application of BABA resulted in a high increase in PPO activity both in plants with and without inoculation. Compared to water-treated plants, treatment with BABA also induced a significant increase of total phenolic compounds as well as of free and total SA in leaves of both inoculated and non-inoculated tomato plants at all sampling times. CAT activity decreased in tomato plants treated with BABA in comparison with the water-treated control plants and the decrease in activity correlated with an increasing total SA accumulation. These findings suggest that BABA treatment resulted in induction of resistance to bacterial wilt in tomato.     

The salicylic acid-dependent defence pathway is effective against different pathogens in tomato and tobacco

The role of salicylic acid (SA) was investigated in basal defence and induced resistance to powdery mildew ( Oidium neolycopersici ) and grey mould ( Botrytis cinerea ) in tomato ( Lycopersicon esculentum ) and tobacco ( Nicotiana tabacum ). A comparison of NahG transgenic tomato and tobacco (unable to accumulate SA) to their respective wild types revealed that in tomato, SA was not involved in basal defence against O. neolycopersici but NahG tobacco showed an enhanced susceptibility to O. neolycopersici infection, the effect becoming more obvious as the plants grew older. In contrast, SA played no role in the basal defence of tobacco against B. cinerea , but seemed to contribute to basal defence of tomato against B. cinerea. Activation of the SA-dependent defence pathway via benzothiadiazole (BTH) resulted in induced resistance against O. neolycopersici in tobacco but not in tomato. Microscopic analysis revealed that BTH treatment could prevent penetration of the Oidium germ tube through tobacco leaves, whereas penetration was successful on tomato leaves irrespective of BTH treatment. In contrast, soil or leaf treatment with BTH induced resistance against B. cinerea in tomato but not in tobacco. It is concluded that the SA-dependent defence pathway is effective against different pathogens in tomato and tobacco.     

利用拮抗的Pseudomonas spp.和无致病力的P.solanacearum防治青枯病的研究

 从番茄、烟和木麻黄根围土壤中分离了606个Pseudomonas spp.菌株,94a和22a对番茄、烟和花生青枯病有一定效果。用番茄青枯菌和花生青枯菌通过Co⁶⁰辐射和紫外光诱变的无致病力菌株,25c、55b对番茄青枯病;45b对花生青枯病;107b对花生青枯病;有一些效果。但不够理想。试验结果证明从植物根围土壤筛选有拮抗作用的P.spp.有可能用于防治青枯病。     

烟草不同发育阶段对赤星病的抗性表现与综合防治技术

人工接种结果表明，随着烟叶自下而上逐渐成熟、衰老，抗病性下降。不同抗性类型的品种，其绿色叶片对病害均表现免疫或近免疫，近成熟叶片高抗，成熟衰老叶片表现为感病，与品种田间抗病性结果一致。田间结果表明，采用增施钾肥、适时打顶和下部叶片近成熟期摘除1～3片底脚叶等措施，提高烟草品种抗病性、配合有效的农药品种综合防治烟草赤星病，在重病区布局抗病品种能有效地推迟病害的发生时期，减慢病情的发展速度，且能减少农药施用量和施用次数，减少环境污染。     

番茄褐色皱果病毒SYBR Green Ⅰ实时荧光RT-PCR检测方法的建立和应用

根据番茄褐色皱果病毒(tomato brown rugose fruit virus,ToBRFV)外壳蛋白(coat protein,CP)的保守基因序列设计l对特异性引物,建立了基于SYBR Green Ⅰ的ToBRFV实时荧光RT-PCR检测方法,并对其进行了特异性、灵敏度检测,对自然感染ToBRFV的番茄、辣椒...     

番茄褐色皱果病毒胶体金免疫试纸条的研制

 番茄褐色皱果病毒(tomato brown rugose fruit virus, ToBRFV)是一种新发病毒,严重威胁番茄的安全生产。为了快速、简便地检测该病毒,我们制备了ToBRFV胶体金免疫试纸条。本研究以ToBRFV粒子为免疫原,通过杂交瘤技术制备了17个抗ToBRFV的单克隆抗体。将不同单抗两两组合分别作为胶体金标记抗体和硝酸纤维素膜检测线上的捕获抗体,共获得272个配对组合的胶体金试纸条。通过特异性测定筛选到一组配对抗体制备的试纸条能够在5 min内特异识别ToBRFV,而与番茄斑驳花叶病毒、番茄花叶病毒、烟草花叶病毒、黄瓜花叶病毒、辣椒轻斑驳病毒、马铃薯X病毒、马铃薯Y病毒、番茄褪绿病毒、番茄斑萎病毒、番茄黄化曲叶病毒等无交叉反应。灵敏度分析表明,该试纸条可从稀释12 800倍的番茄叶片病汁液中检测到ToBRFV,也可检测到50 ng ToBRFV粒子。本研究制备的胶体金试纸条使用方便,灵敏度高,特异性强,适合田间大批量样品检测,可用于ToBRFV的精准监测及早期预警。     

Involvement of jasmonic acid signalling in bacterial wilt disease resistance induced by biocontrol agent Pythium oligandrum in tomato

When the biocontrol agent Pythium oligandrum (PO) colonizes the rhizosphere, it suppresses bacterial wilt disease in tomato (Solanum lycopersicum cv. Micro‐Tom) caused by Ralstonia solanacearum, and a homogenate of its mycelia exhibits elicitor activity, inducing an ethylene (ET)‐dependent defence response in Micro‐Tom. Since salicylic acid (SA) and jasmonic acid (JA) play an important role in plant defence responses to pathogens, the involvement of SA‐ and JA‐dependent signal transduction pathways in resistance to R. solanacearum was investigated in tomato roots treated with a mycelial homogenate of PO. Bacterial wilt disease was also suppressed in tomato cv. Moneymaker treated with the PO homogenate. However, the SA‐inducible PR‐1(P6) gene was not up‐regulated in either Micro‐Tom or Moneymaker. SA did not accumulate in homogenate‐treated roots in comparison with distilled water‐treated controls, even 24 h after inoculation. Induced resistance against R. solanacearum was not compromised in SA‐non‐accumulating NahG transgenic plants treated with the PO homogenate. On the other hand, the expression of the JA‐responsive gene for the basic PR‐6 protein was induced in both tomato cultivars treated with the PO homogenate. Furthermore, quantitative disease assays showed that the induced resistance against R. solanacearum was compromized in PO homogenate‐treated jai1‐1 mutant plants defective in JA signalling. These results indicated that the JA‐dependent signalling pathway is required for PO‐induced resistance against R. solanacearum in tomato.     

Occurrence of Tomato spotted wilt virus (TSWV) in Jordan

Tomato spotted wilt virus was recorded for the first time in Jordan on tomato plants. Severe disease symptoms were observed in different tomato farms in the Jordan Valley. Using a specific primer pair a fragment of the capsid protein gene of the virus has been amplified by RT-PCR and IC-RT-PCR. The amplified PCR product was cloned and sequenced. Sequence analysis revealed that the Jordanian isolate of TSWV shared high nucleotide similarities with other isolates from different countries. The sequence of the capsid protein gene was deposited in GenBank under the accession number AY646682 . The response of different tomato breeding lines and hybrids, previously developed for resistance against Tomato yellow leaf curl virus (TYLCV) were tested for their reaction to TSWV infection. All tested lines and hybrids were susceptible to TSWV infection. This has been confirmed at the molecular level by using the SCAR 421 marker linked to the TSWV resistance gene Sw-5 .