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1.
Dry mycelium (DM) ofPenicillium chrysogenum and its water extract (DME) were examined for their effects on induced resistance against Verticillium wilt and plant growth of cotton in the greenhouse. Soil application of 0.1–5% DM or 0.5–5% DME provided significant protection against the wilt, relative to the control. As neither DM nor DME inhibited mycelial growth ofVerticillium dahliae in vitro, it is suggested that the disease-controlling effects of DM or DME are attributed to induced resistance. DME (5%), as well as DME treated with chloroform or cold acetone, were as effective as 2% DM in reducing disease severity of Verticillium wilt, implying that the resistance-inducing substance(s) in DM are mostly water-soluble, with neither proteins nor lipids likely to be responsible for the induction of resistance. No significant difference in root colonization withV. dahliae was found between control-inoculated and 2% DM- or 5% DME-inoculated plants. However, colonization of hypocotyls and epicotyls was drastically suppressed by either 2% DM or 5% DME relative to the control. Treatments with 2% DM or 5% DME significantly increased ionically-bound peroxidase (POX) activity in roots, hypocotyls and the second leaf of cotton plants, with the hypocotyls expressing the highest increase. Soil application of DM or DME increased plant height, fresh and dry weight of inoculated and non-inoculated cotton plants, relative to their corresponding controls. It is concluded that DM may be used in cotton crops to promote plant growth and to induce resistance againstV. dahliae. POX might be associated with the defense against Verticillium wilt. http://www.phytoparasitica.org posting Jan. 9, 2002.  相似文献   

2.
南方根结线虫中国分离群体种内变异分析   总被引:1,自引:0,他引:1  
为调查我国不同地区和不同寄主上的根结线虫Meloidogyne spp.种类分布以及群体变异情况,基于酯酶和苹果酸脱氢酶同工酶图谱及SCAR分子标记技术对2017—2019年从6省19种植物根部组织分离到的40个根结线虫群体进行鉴定,针对南方根结线虫M. incognita群体分别通过寄主鉴别法进行生理小种鉴别,利用携带Mi抗性基因的番茄进行毒力测试,对2龄幼虫的口针长度和体长进行测量,并对核糖体ITS和线粒体Nad5基因序列进行比较分析。结果显示:根结线虫分离群体经鉴定包括38个南方根结线虫群体和2个象耳豆根结线虫M. erterolobii群体;38个南方根结线虫群体中有35个群体被鉴别为1号生理小种,其余3个群体被鉴别为2号生理小种;发现1个南方根结线虫群体CN19可在携带Mi抗性基因的番茄上侵染繁殖,为毒性群体,其余群体无法进行侵染和繁殖,为无毒群体。南方根结线虫群体2龄幼虫的口针长度和体长均差异较大,而不同寄主来源分离群体的ITS和Nad5基因序列也存在一定变异。基于ITS和Nad5基因序列构建的系统发育树将所有根结线虫群体归为南方根结线虫和象耳豆根结线虫组成的2个独立分支,...  相似文献   

3.
Tsror  Leah  Livescu  L.  Nachmias  A. 《Phytoparasitica》1990,18(4):331-339
The tolerance response to Verticillium in potato is affected by external abiotic and biotic factors. Short-day photoperiod enhanced disease level in the susceptible cvs. ‘Nicola’ and ‘Maris Bard’, as well as in the tolerant cvs. ‘Cara’ and ‘Désirée‘. This was observed under field conditions, where plant reaction in the spring was compared with that in autumn. In some cases the disease was more pronounced in autumn, with its shorter days, than in spring, when the days are longer. The effect was measured by disease symptom severity, fungus colonization in the plants, plant height and final yield. This disease enhancement was more pronounced under controlled growth room conditions, where the only different parameter was illumination. A short photoperiod of 8 h increased the disease level relative to 16 h of light.  相似文献   

4.
为明确琥珀酸脱氢酶抑制剂类(SDHI)杀线剂氟吡菌酰胺对南方根结线虫Meloidogyne incognita的作用效果,在室内盆栽条件下研究不同剂量、不同施药时期该药剂对线虫侵入、根结和雌虫数量以及产卵量的影响。结果显示:在黄瓜幼苗移栽前进行土壤处理,氟吡菌酰胺施用剂量为31.25μg/株时,每株2龄幼虫侵染数量和根结数量分别为11.3条和6.4个,相比对照处理显著减少;在接种南方根结线虫后0~11 d,以施药量为125μg/株的氟吡菌酰胺进行灌根时,可大幅减少根结数量,每株根结数量减少至12.8~22.5个,同时,施药后根系内未见成熟雌虫产生;在接种后15 d,以施药量为250μg/株的氟吡菌酰胺进行灌根时,可大幅减少根内成熟雌虫数量,每株雌虫数量减少至16.9条;接种后20 d施药,施药量为500μg/株时可大幅减少根部产生的根结线虫卵块数量,每株卵块数量减少至18.9个。表明氟吡菌酰胺能抑制土壤内线虫对黄瓜根系的侵染并抑制根内线虫发育,但随着施药时间的推迟,防治已侵入根系的线虫需增加施药剂量,在生产上使用氟吡菌酰胺防治根结线虫病应在作物移栽前或线虫侵染早期施药效果更好。  相似文献   

5.
棉秆生物炭对大丽轮枝菌生长及毒素作用的影响   总被引:1,自引:0,他引:1  
棉花黄萎病难以防治的根源在于大丽轮枝菌Verticillium dahliae Kleb在土壤中形成的微菌核能抵抗不良环境,并在土壤中长期存活,将棉秆加工成生物炭施入棉田,可克服棉秆直接还田的缺点,从源头上防止黄萎病菌进入土壤。为探索棉秆生物炭还田对棉花黄萎病原菌的影响机理,采用液态摇床培养及平皿固态培养法研究生物炭对大丽轮枝菌菌丝生长及微菌核萌发的影响;通过平皿内棉花和甜瓜种子发芽试验研究生物炭对大丽轮枝菌毒素的减毒作用。结果表明:液态培养条件下,棉秆生物炭对大丽轮枝菌菌丝生长抑制作用不明显,在固态培养下对菌丝体生长有一定促进作用;生物炭能减慢微菌核的萌发速率,但对最终萌发率无影响;液态培养中加入棉秆生物碳对大丽轮枝菌毒素有较强的减毒作用。在摇床培养中期,加入2.0 g·L-1生物炭处理与对照棉种在培养12天时的发芽率分别为53.3%与33.3%(P0.05);前期、中期及后期加入0.5 g·L-1生物炭处理的棉花幼苗总长度分别为对照的4.9、2.1倍及3.2倍;加入棉秆生物碳处理甜瓜种子发芽率、胚根长度、胚轴长度及总苗长较对照均有不同程度增加。表明棉杆生物炭对棉花黄萎病菌大丽轮枝菌菌丝生长、微菌核萌发的抑制作用较弱,对大丽轮枝菌毒素危害有较强的减毒作用。  相似文献   

6.
A study was conducted during 2 years to determine the effects of three different control measures on the development of Verticillium wilt on olive trees cv. ‘Nabali’ at Al-Hallabat, Jordan. The causal agent of the wilt wasVerticillium dahliae Kleb. Treating diseased trees with Cryptonol (8-hydroxyquinoline sulfate) in a soil drench, or covering trees with a solar chamber for 15 days, was effective in suppressing disease development. The fertilizer treatment (NPK, 15:15:30) decreased disease severity and percent infection. All decreases are in comparison with the untreated control, and as recorded during the active phase of the pathogen. The treatments did not differ significantly from each other, and disease incidence in treated trees remained lower than in the control throughout the examined period.  相似文献   

7.
In an earlier study, treatment of radish seed with the bacteriumPseudomonas fluorescens WCS374 suppressed fusarium wilt of radish (Fusarium oxysporum f. sp.raphani) in a commercial greenhouse [Leemanet al., 1991b, 1995a]. In this greenhouse, the areas with fusarium wilt were localized or expanded very slowly, possibly due to disease suppressiveness of the soil. To study this phenomenon, fungi were isolated from radish roots collected from the greenhouse soil. Roots grown from seed treated with WCS374 were more abundantly colonized by fungi than were roots from nonbacterized plants. Among these were several species known for their antagonistic potential. Three of these fungi,Acremonium rutilum, Fusarium oxysporum andVerticillium lecanii, were evaluated further and found to suppress fusarium wilt of radish in a pot bioassay. In an induced resistance bioassay on rockwool,F. oxysporum andV. lecanii suppressed the disease by the apparent induction of systemic disease resistance. In pot bioassays with thePseudomonas spp. strains, the pseudobactin-minus mutant 358PSB did not suppress fusarium wilt, whereas its wild type strain (WCS358) suppressed disease presumably by siderophore-mediated competition for iron. The wild type strains of WCS374 and WCS417, as well as their pseudobactin-minus mutants 374PSB and 417PSB suppressed fusarium wilt. The latter is best explained by the fact that these strains are able to induce systemic resistance in radish, which operates as an additional mode of action. Co-inoculation in pot bioassays, ofA. rutilum, F. oxysporum orV. lecanii with thePseudomonas spp. WCS358, WCS374 or WCS417, or their pseudobactin-minus mutants, significantly suppressed disease (except forA. rutilum/417PSB and all combinations with 358PSB), compared with the control treatment, if the microorganisms were applied in inoculum densities which were ineffective in suppressing disease as separate inocula. If one or both of the microorganism(s) of each combination were applied as separate inocula in a density which suppressed disease, no additional suppression of disease was observed by the combination. The advantage of the co-inoculation is that combined populations significantly suppressed disease even when their individual population density was too low to do so. This may provide more consistent biological control. The co-inoculation effect obtained in the pot bioassays suggests that co-operation ofP. fluorescens WCS374 and indigenous antagonists could have been involved in the suppression of fusarium wilt of radish in the commercial greenhouse trials.Abbreviations CFU colony forming units - KB King's B - PGPR plant growth-promoting rhizobacteria - CQ colonization quotient  相似文献   

8.
福建省漳州市一基地毛豆(品种:‘毛豆64’)苗期发生严重根结线虫病, 发病株率为78%。为明确其病原的种类及其初侵染来源, 通过形态学、分子生物学方法进行了种类鉴定。研究结果表明, 该线虫雌虫、雄虫、2龄幼虫(J2)的形态学特征与测量值和拟禾本科根结线虫Meloidogyne graminicola相吻合;基于线虫rDNA-ITS序列和28S rDNA D2D3序列构建的系统发育树进一步确定其为拟禾本科根结线虫;室内接种试验确定了其致病性。这是首次在福建省毛豆上发现拟禾本科根结线虫。在毛豆基地畦地残留的前作水稻稻茬根内和根际土壤中均分离到大量J2s, 经特异性引物扩增确定为拟禾本科根结线虫, 研究认为前作水稻根系受拟禾本科根结线虫侵染, 在灌溉淹水状态下线虫2龄幼虫和卵在根内与土壤中长期存活, 成为轮作毛豆根结线虫病的初侵染源。  相似文献   

9.
A study was conducted in two greenhouses with a history of Fusarium crown and root rot (Fusarium oxysporum f.sp.radicis-lycopersici, Forl) and root-knot nematodes (Meloidogyne javanica andM. incognita). During the 2005–06 growing season, the effectiveness of soil disinfestation by solarization in combination with low doses of metham-sodium (500, 750, 1000 and 1250l ha−1) or dazomet (400 g ha−1), was tested against soilborne pathogens and nematodes in an attempt to find a suitable alternative to methyl bromide, which is soon to be phased out. Solarization alone was not effective in the greenhouse with a high incidence ofForl. In the greenhouse with a low level ofForl, all the treatments tested reduced disease incidence, and were therefore considered to be applicable for soil disinfestation. In addition, root-knot nematode density decreased with all the treatments tested in both of the greenhouses.  相似文献   

10.
The inheritance of resistance toFusarium oxysporum f.sp.cucumerinum race 1 was determined in the cucumber cv. WIS-248 by analyzing segregation of F1, F2, and BC populations of crosses with the susceptible cv. Straight-8. Resistance was conferred by a single dominant gene. In an allelism test, it was proven that theFcu-1 gene, which confers resistance toF. oxysporum f.sp.cucumerinum races 1 and 2 in cucumber cv. SMR-18 and theFoc gene, which confers resistance toF. oxysporum f.sp.cucumerinum race 2 in cucumber cv. WIS-248, are indistinguishable.  相似文献   

11.
Three trials were carried out during the years 2002–2005 at the Agricultural Experimental Center of Albenga (northern Italy) on gerbera plants grown in a closed soilless system. The efficacy of slow sand filtration and UV treatment in eliminatingFusarium oxysporum f.sp.chrysanthemi (Foc) propagules, naturally present or artificially added to the recirculating nutrient solution, was evaluated. These techniques were tested alone and in combination with the application into the soilless system of different antagonistic strains ofFusarium spp. andTrichoderma spp., isolated from gerbera rhizosphere, and of a commercial formulation ofStreptomyces griseoviridis. The role of the nutrient solution pH in reducingFoc infections was also evaluated. Results showed that slow sand filtration, alone and in combination with the application of biocontrol agents, and a nutrient solution pH higher than 6.0, may induce a significant reduction inFoc infections on gerbera plants grown in closed soilless systems. http://www.phytoparasitica.org posting June 8, 2008. Corresponding author  相似文献   

12.
棉隆与淡紫拟青霉联合防治番茄根结线虫病的效果评价   总被引:4,自引:0,他引:4  
为明确土壤熏蒸与生防微生物对番茄根结线虫病的联合作用效果,采用移栽前棉隆熏蒸处理后穴施淡紫拟青霉Paecilomyces lilacinus YES-2-14生防菌剂的方法在温室大棚开展了联合防治试验。结果表明,棉隆用量为35 g/m~2时,24周拉秧时线虫数量减少90%以上,防效达到85.5%;移栽时穴施浓度10~7~10~8CFU/g的淡紫拟青霉菌剂,24周拉秧时防效为44.4%~59.6%;而当线虫初始密度达到674头/100 g土时,单一菌剂防效只有12.5%,但番茄长势和产量显著提高。棉隆熏蒸后再联合施用淡紫拟青霉菌剂,2个月和5个月时防效比单一棉隆处理分别提高14.1%和21.8%,比单一菌剂处理提高14.3倍和4.1倍,产量较对照、棉隆熏蒸和单一菌剂处理分别提高22.1%、9.5%和2.4%,且该处理地块线虫数量始终最低,与对照差异显著,而淡紫拟青霉数量则高于单一淡紫拟青霉菌剂处理。表明棉隆和淡紫拟青霉菌剂联合使用不仅能显著降低线虫数量,有效防治番茄根结线虫病,还能够促进植株生长并提高产量。  相似文献   

13.
A molecular protocol is presented for distinguishing seven of the most common and economically important Meloidogyne spp. DNA was extracted from individual second-stage juvenile (J2) nematodes of Meloidogyne spp. and amplified by PCR (polymerase chain reaction). Fifteen PCRs including amplification of rDNA, specific SCAR (sequence characterized amplified region) and RAPD (random amplified polymorphic DNA) fragments were possible from the extracted DNA. This enabled a molecular diagnostic key for M. incognita , M. javanica , M. arenaria , M. mayaguensis , M. hapla , M. chitwoodi and M. fallax to be designed. The key unifies published methods into a single logical schematic using primer combinations that were previously validated and shown to work reliably and specifically. The protocol can be used with single juvenile or adult nematodes and the schematic can readily be expanded to accommodate more species. The use of RAPD amplification to assist with identification of samples which do not yield diagnostic amplification products after the first three steps of the molecular key is also described.  相似文献   

14.
玫瑰黄链霉菌Men-myco-93-63是从马铃薯疮痂病自然衰退土壤中筛选到的对多种重要植物病原菌具有较强抑制作用的拮抗链霉菌,其发酵液对根结线虫具有较好的防治作用。为明确Men-myco-93-63活菌片剂在蔬菜根结线虫防治中的应用前景,采用温室盆栽法和稀释平板法研究了Men-myco-93-63活菌片剂对黄瓜根结线虫病的防治效果及对土壤微生物区系的影响。结果表明:Men-myco-93-63片剂对黄瓜根结线虫病具有较好的防效,1.0和1.5 g/株用量下防效分别为51.85%和55.56%,而对照药剂淡紫拟青霉颗粒剂1.5 g/株及M en-myco-93-63固体发酵物(发酵物与病土体积比为1∶200)的防效分别为54.17%和50.00%;施药60d后,该片剂对植株根际土壤中微生物区系影响较大,1.0 g/株用量下,细菌和放线菌数量分别比空白对照增加了225.45%和75.45%,真菌数量降低了66.43%,3种可培养微生物的总量比空白对照增加了195.35%,表明M en-myco-93-63片剂的施用可明显改善根际土壤中的微生物结构。  相似文献   

15.
为探明长枝木霉Trichoderma longibrachiatum菌株TL16防治南方根结线虫Meloidogyne incognita的作用机理,采用原生质体转化法获得绿色荧光蛋白(green fluorescent protein,GFP)标记菌株GFP-TL16,通过测定菌株TL16和GFP-TL16对南方根结线虫卵和2龄幼虫(2nd-stage juvenile,J2)的寄生与致死作用,其发酵液对卵孵化的抑制作用和对J2的致死作用,以及菌株GFP-TL16在黄瓜根系的定殖情况和菌株TL16对番茄根结形成的抑制作用来综合分析其作用机理。结果显示:菌株TL16菌丝对南方根结线虫卵无寄生作用,处理19 d后卵降解率为26.33%,致死作用较低;菌株TL16分生孢子悬浮液处理南方根结线虫J2后72 h的致死率为1.65%,且无寄生作用。菌株TL16发酵液处理南方根结线虫J2后48 h的校正死亡率为10.71%,处理卵15 d后对卵孵化的相对抑制率为77.11%。菌株GFP-TL16可定殖于黄瓜根系中,经菌株TL16处理后接种南方根结线虫J2,番茄根结减退率为55.88%。表明长枝木霉菌株TL16可通过抑制根结线虫卵孵化和诱导番茄产生抗病性来防治根结线虫病。  相似文献   

16.
铵态氮和硝态氮对香蕉枯萎病发生的比较研究   总被引:5,自引:0,他引:5  
 为寻找降低香蕉枯萎病发生的防治措施,通过室内盆栽接种试验,研究了铵态氮(NH4+-N)和硝态氮(NO3--N)对香蕉枯萎病发生及其植株叶绿素含量、气体交换参数、病原菌在植物体内的数量分布和植物钙(Ca)、镁(Mg)、铁(Fe)、钼(Mo)、可溶性糖和木质素含量的效应。结果表明:不接种病原菌的条件下,不同氮素处理对香蕉幼苗生长影响无差异;接菌情况下,与NH4+-N处理相比,NO3--N处理显著降低植株各器官的病原菌数量、发病率和发病严重程度。病原菌侵染后,不同氮素处理下植株光合作用均显著下降:NO3--N处理香蕉苗保持比NH4+-N处理更高的光合速率;病原菌侵染后NH4+-N处理的植株Ca、Mg、Fe和Mo含量相对于侵染前没有显著差异,但NO3--N处理下此4种元素含量均显著升高。病原菌侵染后的植株叶片可溶性糖含量在不同氮素处理中都没有显著变化,但在根系中,NO3--N处理的侵染植株可溶性糖含量显著降低。与此同时,病原菌侵染后,木质素含量在NH4+-N处理植株中变化不显著,但其含量在NO3--N处理侵染后显著上升。综上所述,NO3--N处理可增加植株抗病相关矿质元素的吸收,诱导香蕉苗木质素形成,使其木质化程度增加,从而维持较高的光合作用,保持较高的抗病水平。  相似文献   

17.
水稻根结线虫病是严重危害水稻生产的主要病害之一,目前尚无成本低且安全有效的防控方法。本研究通过田间小区试验评价了直播、移栽和直播前撒施0.2 kg/667 m 210%噻唑膦颗粒剂(GR)3种种植方式下水稻根结线虫病发生及危害情况。结果表明,与直播相比,移栽田移栽后25 d水稻根结线虫的抑制率达到94.26%,根结指数为1.97,与直播前撒施0.2 kg/667 m 210%噻唑膦GR化学药剂处理组无显著差异;移栽后55 d水稻根结线虫的抑制率为58.56%。同时,移栽田移栽后25 d和55 d根结线虫2龄幼虫虫口减退率分别达到77.63%和72.22%。此外,移栽田水稻株高与根长均高于直播处理组及直播前撒施10%噻唑膦GR处理组;产量比直播处理组增加26.34%,直播处理组产量和直播前撒施10%噻唑膦GR处理组没有显著差异。因此,在水稻根结线虫病发生严重的田块采用移栽方式种植,可显著抑制根结线虫的发生为害,是一种安全、有效的防控措施。  相似文献   

18.
为掌握新疆主要植棉区棉花黄萎病的发生现状及其病原菌大丽轮枝菌Verticillium dahliae的落叶型菌系分布以及遗传变异情况,于2015年对26个新疆主要植棉区棉花黄萎病的发生情况进行了随机调查,统计新疆大丽轮枝菌的培养性状,利用大丽轮枝菌落叶型特异引物D1/D2、INTD2F/INTD2R与非落叶型特异性引物ND1/ND2、INTNDF/INTNDR对新疆大丽轮枝菌菌系进行互补鉴定,并对部分菌系的遗传变异进行简单序列重复区间(inter simple sequence repeat,ISSR)分析。结果表明:2015年新疆棉花黄萎病发病田比例为54.0%,其中病情指数在10.0以上的发病田与2013年持平,而病情指数在20.0以上的严重发病田比例为10.8%,比2013年增加3.8个百分点;新疆大丽轮枝菌的培养性状以菌核型为主,比例为70.1%,菌丝型与中间型比例分别为13.4%和16.5%;新疆大丽轮枝菌落叶型菌系比例为53.2%,26株菌株的来源地全部检出落叶型菌系;聚类分析结果显示,当遗传相似系数为0.66时,新疆大丽轮枝菌落叶型与非落叶型菌系聚为2个谱系,菌系地理来源、培养性状与大丽轮枝菌的遗传分化无明显相关性。  相似文献   

19.
Verticillium dahliae Kleb. with a complicated genetic diversity is a widely distributed major pathogen resulting in cotton wilt, which causes high economic losses in cotton lint production in the cotton belt of Turkey. A collection of 70 TurkishV. dahliae isolates (68 from wilted cotton plants in 28 districts and two from watermelon plants in two districts) were tested for vegetative compatibility by observing heterokaryon formation among complementary nitrate-nonutilizing (nit) mutants. The mutants were tested against international reference tester isolates and also were paired with one another. Thirty-nine isolates were assigned to vegetative compatibility group (VCG) 2B, 19 to VCG2A and three to VCG4B. One isolate was self-incompatible and eight others could not be assigned to any of the identified VCGs because theirnit mutants showed negative reactions with the tester isolates of four VCGs or theirnit mutants reverted back to the wild type. This is the first report of VCGs inV. dahliae from cotton in Turkey.  相似文献   

20.
为明确棉花内生真菌CEF-373菌株对棉花黄萎病的防效及其作用机理,利用圆盘滤膜法和平板对扣培养法测定菌株CEF-373对大丽轮枝菌Verticillium dahliae菌丝生长的抑制作用,测定其对棉花黄萎病的温室和田间防效,并通过活性氧含量及防御基因表达情况来分析其作用机理。结果表明,菌株CEF-373的挥发性代谢产物和非挥发性代谢产物对大丽轮枝菌菌丝的生长均有显著抑制作用,抑制率最高分别可达37.75%和100.00%。用1×107CFU/mL的菌株CEF-373分生孢子悬浮液灌根后,对棉花黄萎病的温室防效可达71.12%,用质量比为3%的菌株CEF-373固体菌剂拌土栽培后,对棉花黄萎病的温室防效可达62.74%,防治作用显著。菌株CEF-373的发酵液滴灌和微生物肥料处理40 d后,对棉花黄萎病的田间防效达到最大,分别为36.23%和27.71%,而在后期有所降低。菌株CEF-373可以诱导棉花叶片中细胞活性氧的爆发;且菌株CEF-373成功激活了苯丙氨酸解氨酶、过氧化物酶、多酚氧化酶、几丁质酶和病程相关蛋白基因PR10的表达,对大丽轮枝菌的侵染具有抵御作用。表明棉花内生真菌CEF-373菌株通过抑制大丽轮枝菌生长以及诱导寄主系统抗病性来有效防治棉花黄萎病,具有较好的生物防治应用前景。  相似文献   

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