首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 187 毫秒
1.
在2007-2008年的一项温室测验中,10株黄瓜幼苗内生真菌表现出了对南方根结线虫较好的防效,为了阐明其作用方式,用裂根试验设计研究了10个菌株诱导黄瓜产生根结线虫抗性的能力.同一植株的根系被分为彼此隔离的挑战根系和应答根系,镰刀菌Fusarium spp.菌株Fu234和Fu654、毛壳菌Chaetomium sp.菌株Ch1001、叶点霉Phyllosticta sp.菌株Ph511在挑战根系中接种后,应答根系中的线虫入侵总数显著降低,较对照分别降低了42.4%、35.7%、38.4%、23.6%(第1次测定)和63.6%、45.2%、51.0%、37.0%(重复测定),这4个菌株诱导了黄瓜对根结线虫入侵的抗性.同时,Fu234、Fu654、Ch1001和拟青霉Paecilomyces sp.菌株Pa972接种后应答根系中的卵与雌虫的比值显著减少,相比对照其比值分别降低了24.3%、37.7%、48.3%、21.2%(第1次测定)和21.6%、39.8%、30.0%、46.2%(重复测定),这4个菌株诱导了黄瓜对根结线虫繁殖的抗性.  相似文献   

2.
大豆胞囊线虫是大豆生产中的主要病害之一,由于化学防治存在费用高,效果不佳,污染环境和危害人畜安全等方面的诸多问题,生物防治成为了防治大豆胞囊线虫的新方法。本试验利用体外生物测定方法,研究了费氏中华根瘤菌Sinorhizobium fredii Sneb183对大豆胞囊线虫二龄幼虫的存活、卵孵化、呼吸作用以及体液渗透的影响。结果表明,根瘤菌Sneb183处理幼虫72 h后,死亡率达86.7%,处理初期,线虫出现活动迟缓等症状,而后表现出整个身体僵直的死亡症状;对卵的孵化抑制率可达59.4%;根瘤菌Sneb183对二龄幼虫呼吸有较强抑制作用,处理24 h后,耗氧量下降93.1%;同时根瘤菌Sneb183发酵液可引起二龄幼虫体液渗漏,处理48 h后电导率增加了62.4%。因此,根瘤菌Sneb183可成为大豆胞囊线虫病生物防治资源中的新成员。  相似文献   

3.
 根结线虫病严重威胁各类蔬菜作物的生产,是世界上最难防治的土传病害之一。利用生防细菌能够有效地控制蔬菜根结线虫种群数量并降低危害。荧光假单胞菌Sneb825是本实验室筛选出的对南方根结线虫病具有较高防效的生防细菌。本研究通过盆栽试验、裂根试验和温室试验验证了荧光假单胞菌Sneb825诱导番茄抗南方根结线虫侵染的防治效果;通过酶联免疫法(ELISA)和实时荧光定量PCR检测了番茄根系内活性氧与木质素含量及其相关基因表达量的变化。研究发现,Sneb825菌株发酵液不但能够有效降低南方根结线虫对番茄的侵染,而且对番茄植株有显著的促生作用。Sneb825菌株发酵液灌根处理并接种南方根结线虫二龄幼虫后,番茄根系内活性氧(10 dpi)和木质素含量(5 dpi)显著高于空白对照;活性氧合成相关基因RBOH1(10 dpi)和过氧化物酶基因Ep5C(10 dpi)以及木质素合成相关基因Tpx1(5 dpi)的表达量均达到最高值。研究结果表明活性氧和木质素的大量积累是荧光假单胞菌Sneb825诱导番茄抑制南方根结线虫侵染的防御对策之一。荧光假单胞菌可以有效的防治根结线虫病,在农业生产实践中具有潜在的应用前景。  相似文献   

4.
芽孢杆菌Sneb709控制番茄根结线虫病及其促生效果研究   总被引:1,自引:0,他引:1  
通过鞭毛形态观察和16S r DNA序列分析,对本实验室前期研究中筛选出的1株对南方根结线虫(Meloidogyne incognita)有拮抗作用的菌株Sneb709进行了鉴定,并测定了其发酵液对番茄根结线虫病的生物活性。结果表明,菌株Sneb709为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),其发酵液对南方根结线虫2龄幼虫有致死作用,24 h后致死率为91.67%,对其卵孵化的相对抑制率为87.50%。盆栽和温室大棚试验结果表明,解淀粉芽孢杆菌Sneb709发酵液能显著提高番茄植株的株高和根长,降低根结指数、根鲜重和干重,增加果实的数量和重量。  相似文献   

5.
根结线虫的严重发生给农作物生产造成巨大经济损失,生物防治是控制该病的一种安全有效措施。本研究从448株根瘤内生细菌分离株中筛选出3株对南方根结线虫有较好防效的生防细菌Sneb1994、Sneb1995和Sneb2000,3个菌株发酵滤液对南方根结线虫2龄幼虫(J2)均有高毒杀活性,处理24 h校正死亡率达85%以上,同时对卵孵化具有抑制作用,并可促进番茄种子生长。盆栽试验结果表明,3个菌株发酵液灌根处理均能显著减少根结数和卵囊数,相对防效为37.95%~44.51%,同时促进番茄植株的生长。经形态特征、生理生化特性和16S rDNA序列分析,鉴定菌株Sneb1994、Sneb1995和Sneb2000分别为氧化微杆菌Microbacterium oxydans、油菜假单胞菌Pseudomonas brassicacearum和蜡样芽胞杆菌Bacillus cereus。氧化微杆菌为首次报道对根结线虫有效的生防菌株。这些根瘤内生细菌菌株的发掘,为植物线虫病害的生物防治提供了新的微生物资源。  相似文献   

6.
本研究从线虫拮抗土壤、线虫拮抗植物根表、普通植物根表,并首次尝试从北方根结线虫雌虫和大豆胞囊线虫胞囊上,分离筛选具有防治危险性线虫病害潜力的生防细菌。在室内试验中,10株细菌菌株对北方根结线虫J2和南方根结线虫具有一定致死作用,其中9株能杀死大豆胞囊线虫J2。在温室试验中,8株菌株对线虫病害的防效在38.2%~66.2%之间。经鉴定,这些细菌分别属于假单胞菌属(Pseudo- monas spp.)和芽孢杆菌属(Bacillus spp.)。  相似文献   

7.
生防细菌YC-10的杀线虫活性及其鉴定   总被引:2,自引:0,他引:2  
 从烟草中分离出1株对根结线虫和胞囊线虫有较高生物活性的内生细菌菌株-YC-10。将该细菌发酵滤液原液及5、10、20和40倍稀释液处理南方根结线虫,96 h后线虫死亡率均达到100%,处理大豆胞囊线虫96 h,致死率大于90%,在植物线虫生物防治上显示出巨大的应用前景。通过形态特点、理化特征以及16SrDNA序列同源性分析将菌株YC-10鉴定为苏云金芽孢杆菌(Bacillus thuringiensis)。对发酵液活性成分理化性质研究表明,活性成分对热稳定,高温、蛋白酶K处理不影响其杀虫活性,而酸性条件下杀线虫活性比碱性中更强。为后续杀线虫活性成分的分离及杀线虫机理研究奠定基础。   相似文献   

8.
淡紫拟青霉对大豆胞囊线虫卵及2龄幼虫的影响   总被引:29,自引:2,他引:29  
研究了淡紫拟青霉M-14、IPC菌株对大豆胞囊线虫卵孵化及2龄幼虫活性的影响。结果表明,M-14滤液及其菌丝内溶物、IPC滤液、ZnCl_2溶液等不同处理间存在极显著差异(P<0.01)。代谢产物对卵生理活性的影响因试验菌株的不同而异,M-14菌株发酵滤液及其内容物对大豆胞囊线虫卵的孵化具有强烈的抑制作用,而IPC菌株的影响则较弱。大豆胞囊线虫2龄幼虫在M-14发酵滤液原液及1倍稀释液中均表现为麻痹僵直,线虫死亡率随时间的延长而增加,72h后幼虫死亡率分别达到96.8%和90.5%。将经M-14原液处理24h的幼虫置于清水中,仅有极少数能够恢复活性,证明M-14代谢产物具有很强的杀线虫活性。  相似文献   

9.
小麦叶锈病是小麦生产上的重要病害,防治该病害主要采用抗病品种和喷施化学农药,而探索生物防治是防治该病的一种新方法。本研究使用3株细菌菌悬液对小麦种子进行处理,于小麦一叶期接种叶锈病菌10d后调查其发病率和严重度。结果表明,在盆栽试验中,Sneb1462菌株菌悬液诱导小麦抗叶锈病的效果最好,可使发病率和严重度比对照分别降低27.54%和49.90%;Sneb1462还可促进小麦根部生长,施用后小麦根长和地下部鲜重分别比对照提高30.19%和29.03%。在大田试验中,用Sneb1462菌悬液处理小麦种子后叶锈病的严重度降低38.60%,小麦株高和穗重分别提高16.44%和34.98%,表明该菌株是一株优良的抗病促生菌。经透射电镜观察、16SrDNA序列分析及生理生化的检测,鉴定该菌株为多黏类芽胞杆菌Paenibacillus polymyxa。利用生防细菌Sneb1462进行种子处理防控小麦叶锈病将是一种新型的植保措施,具有重要的研究意义。  相似文献   

10.
芽孢杆菌BH1防治大豆根腐病的效果及机制   总被引:15,自引:0,他引:15  
芽孢杆菌BH1分离于大豆根际,在温室试验中表现出较好的防治效果。田间试验对尖孢镰刀菌引起的大豆根腐病防效达56.1%,增产7.6%。该菌株发酵无菌滤液对尖孢镰刀菌F3、茄孢镰刀菌W1和镰刀菌Sl孢子萌发和菌丝生长有抑制作用;对热处理较稳定。对其抗利福平标记株B-R^ -4与大豆根系的亲和性研究表明,BH1可定殖于无菌土和病土中生长的大豆根际,且动态变化趋势相似,但在无菌土中数量略高于病土。组织印记法表明:B-R^ -4可在整个大豆根系生长。扫描电镜观察发现,BH1主要存在于根表凹陷处,在根尖或侧根处则很少。透射电镜观察,根细胞间隙内未检测到BH1。在大豆根际的定殖试验说明,B-R^ -4与大豆根系有很好的亲和性,对营养和空间位点的竞争是其拈抗病原菌的主要机制。  相似文献   

11.
大豆胞囊线虫Heterodera glycinesIchinohe病害是大豆生产中的毁灭性病害,对世界大豆生产造成重大损失。采用根染色法和常规土壤线虫分类鉴定技术研究了连作和轮作两种耕作方式下大豆胞囊线虫群体数量和土壤线虫群落结构的变化。结果表明,连作使大豆田土壤中胞囊和根系上各龄期胞囊线虫数量显著增加(95.6→335.5),而轮作积累很少(10.3→31.8),感病品种中J2的侵入数量决定了大豆胞囊线虫形成胞囊的数量(22.8→95.6,129.4→335.5)。玉米-玉米-大豆的轮作方式使胞囊积累最少(10.3)。轮作大豆田土壤线虫总数高于连作,主要由于轮作大豆田土壤线虫的优势属Helicotylenchus和优势营养类群植物寄生线虫PP的相对丰度高于连作,但大豆胞囊线虫的相对丰度正相反,连作(33.65%)高于轮作(0.91%),说明Heterodera glycines可以作为土壤线虫的关键属种用以指示土壤发病的严重程度。研究中重要的优势属和关键属种cp值均为3,说明其繁殖和抗干扰能力比较强。研究证明土壤线虫优势营养类群、优势属种和关键属种可以有效地指示农业土壤健康状况和大豆田的大豆胞囊线虫病害的发生程度。  相似文献   

12.
大豆孢囊线虫病是威胁大豆生产的重大病害之一。2015-2016年,采用随机取样的方法对贵州省大豆孢囊线虫的发生和分布情况进行了调查。调查范围包括贵阳、六盘水、安顺、毕节、黔西南和遵义等6个地区下辖的14个县(区),共采集土样287份。调查结果表明,贵州省大豆孢囊线虫的总检出率为28.2%,其中毕节地区的大方县和赫章县孢囊检出率最高,分别达到46.7%和45.0%,而在遵义市、贵阳市和黔西南州孢囊检出率为0。六盘水地区的水城县孢囊发生量最大,平均孢囊数为3.4个/200g土,最大孢囊数达到17个/200g土;安顺地区的镇宁和关岭县大豆孢囊线虫发生程度最轻,每200g土样平均孢囊数分别为0.3和0.2个,最大孢囊数仅为2个/200g土。分离的孢囊主要形态特征与大豆孢囊线虫一致,并且ITS序列与甘肃大豆孢囊线虫种群序列一致性达100%。根据形态学观察和ITS序列分析比对,将贵州省采集到的孢囊线虫鉴定为大豆孢囊线虫。本研究结果可为有效防控贵州省大豆孢囊线虫病提供依据。  相似文献   

13.
为了解甘肃省陇东南地区大豆孢囊线虫病分布和发生程度,采用Z字形取样法,对甘肃省陇东南地区9个县(区)37个乡镇大豆孢囊线虫病的发生和分布进行调查,并根据形态特征和rDNA-ITS序列比对鉴定线虫种类。共采集土样411份,陇东地区大豆孢囊线虫检出率为87.2%,其中镇原、西峰、正宁、华池和环县的检出率最高,达100%,镇原孢囊发生量最大,平均孢囊数为11.4个/100 g土;陇南地区大豆孢囊线虫检出率为63.7%,成县和徽县分别为64.0%、63.0%,平均孢囊数分别为0.9和1.2个/100 g土。经形态学特征观测和rDNA-ITS序列比对,甘肃省陇东南采集到的孢囊线虫均鉴定为大豆孢囊线虫Heterodera glycines。  相似文献   

14.
襄汾县大豆孢囊线虫病的发生规律及防治技术研究   总被引:1,自引:0,他引:1  
大豆孢囊线虫在襄汾县一般1a发生4代.该线虫主要分布在15cm以内的耕作层,降雨对它的垂直分布影响较大,雨后线虫下移.受害程度不受播期影响.不同的大豆品种对线虫有抗性差异.田间药剂试验表明,5%涕灭威颗粒剂土施防效最好,表现出明显的增产作用.  相似文献   

15.
ABSTRACT The soybean cyst nematode, Heterodera glycines, and the fungus that causes sudden death syndrome (SDS) of soybean, Fusarium solani f. sp. glycines, frequently co-infest soybean (Glycine max) fields. The interactions between H. glycines and F. solani f. sp. glycines were investigated in factorial greenhouse experiments with different inoculum levels of both organisms on a soybean cultivar susceptible to both pathogens. Measured responses included root and shoot dry weights, H. glycines reproduction, area under the SDS disease progress curve, and fungal colonization of roots. Both H. glycines and F. solani f. sp. glycines reduced the growth of soybeans. Reproduction of H. glycines was suppressed by high inoculum levels but not by low levels of F. solani f. sp. glycines. The infection of soybean roots by H. glycines did not affect root colonization by the fungus, as determined by real-time polymerase chain reaction. Although both pathogens reduced the growth of soybeans, H. glycines did not increase SDS foliar symptoms, and statistical interactions between the two pathogens were seldom significant.  相似文献   

16.
ABSTRACT The dynamics of Heterodera glycines spatial patterns were studied under different tillage systems in two naturally infested soybean fields in Iowa from 1994 to 1997. At each location, there were four different tillage treatments (conventional tillage, reduced tillage, ridge tillage, and no tillage). Soil samples were taken from 98 contiguous quadrats (5.2 m(2)) per plot in the fall of 1994, before any tillage was performed, and in the spring of the following 3 years shortly after planting. Cysts were extracted from soil samples by elutriation and counted, and eggs were extracted from cysts and enumerated. Spatial patterns of H. glycines populations were characterized by geostatistical analysis and variance-to-mean (VM) ratios. Semivariance values were calculated for cyst and egg densities and semivariograms were constructed. In general, there was greater spatial dependence among cyst populations than egg populations. In one field with a strongly aggregated initial H. glycines population, tillage practices resulted in changes in spatial patterns of H. glycines populations, characterized by spherical-model semivariogram parameters (sill, nugget effect, and range of spatial dependence). These parameters indicated increasing aggregation over time in no tillage and ridge tillage treatments, but decreasing aggregation in reduced and conventional tillage treatments. There was an increase of 350% in sill values (maximum semivariance) for cyst populations after 3 years of no tillage, but in the conventional tillage treatment, sill values remained unchanged or decreased over time as tillage was implemented. Semivariograms for cyst and egg population densities revealed strong anisotropy (directional spatial dependence) along soybean rows, coincident with the direction of tillage practices. VM ratios for cyst counts increased each year in the no tillage and ridge tillage treatments, but decreased for 2 years in reduced tillage and conventional tillage treatments. Final VM ratios for cyst and egg counts were highest in the no tillage treatment. In a second field, with low initial aggregation of H. glycines populations, there was little measurable change in semivariogram parameters after 3 years of no tillage, but in the conventional tillage treatment, populations became less aggregated, as the range, sill, and the proportion of the sill explained by spatial dependence decreased for cyst population densities. Our results indicated that in soybean fields with initially aggregated populations of H. glycines, no tillage and ridge tillage systems promoted aggregation of the nematode population, whereas conventional and reduced tillage systems resulted in a less aggregated spatial pattern.  相似文献   

17.
 形态学观测和寄生性研究结果表明,发生于我国河南省兰考县泡桐(Pauloumia sp.)和内蒙古自治区凉城县豌豆(Pisum sativum)上的胞囊线虫均属于大豆胞囊线虫(Heterodera glyeines);上述两种植物上的胞囊线虫均可侵染大豆,在根部形成有卵雌虫。而兰考和凉城两地大豆上的胞囊线虫群体可分别在泡桐成豌豆上良好繁殖。以上结果证明,泡桐和豌豆为大豆胞囊线虫的两种新寄主植物,其中,泡桐为大豆胞襄线虫侵染多年生乔木植物的首例报道。  相似文献   

18.
 在山东省5个植烟县/市采集烟草线虫土壤样本24份,其中10份土样中分离到孢囊线虫的孢囊,对之进行系统的形态学观测。孢囊阴门锥突出,双半膜孔,下桥和泡囊发达,阴门裂长(44.1±3.5) μm,阴门窗长(50.4±4.8) μm、宽(36.6±4.1) μm,下桥长(83.8±4.7) μm、宽(11.0±0.9) μm。利用大豆孢囊线虫特异性引物对分离到的孢囊线虫群体进行了分子鉴定。形态学和分子鉴定结果表明,山东省寄生烟草的孢囊线虫为大豆孢囊线虫Heterodera glycines Ichinohe,1952。对这10个孢囊线虫群体rDNA-ITS区进行了PCR扩增产物用7种限制性内切酶进行酶切和测序比对。发现,所有孢囊线虫群体均能扩增出一条大约1 000 bp大小的片段;用Alu Ⅰ、Bsh 1236 Ⅰ、Hae Ⅲ、Hha Ⅰ 、Mva Ⅰ 、Rsa Ⅰ酶切后,产生的酶切表型均相同;用Ava I酶切后,产生了2种酶切表型。所测孢囊线虫群体与GenBank收录的大豆孢囊线虫序列相似度高达99%以上。  相似文献   

19.
辽宁省大型真菌浸提液及发酵液对线虫的毒力作用   总被引:2,自引:0,他引:2  
利用从辽宁省采集的206株大型野生真菌的浸提液和部分发酵液,测定其对根结线虫Meloidogyne incognita、胞囊线虫Heterodera glycines、小杆线虫Caenorhabditis sp.和水稻干尖线虫Aphelenchoides basseyi的活性。结果表明:有22种真菌对靶标线虫的致死率达70%以上,且同一菌株的浸提液和发酵液对线虫亦有明显的选择毒性作用。有7株菌浸提液对2种以上靶标线虫的致死率超过90%。蛇头菌Mutinus caninus F149浸提液对南方根结线虫毒力最高,致死率达97.74%,对胞囊线虫和水稻干尖线虫的毒力也超过90%,而对小杆线虫毒力仅为24.04%,因其对人毒性大而未获得纯培养。薄蜂窝菌Hexagonia tenuisF128浸提液对大豆胞囊线虫J2毒力最高,致死率达96.55%,但其发酵液毒力下降;浸提液对根结线虫的毒力仅次于F149,对水稻干尖线虫毒力较弱,但发酵液对干尖线虫致死率却提高至91.38%。块鳞青鹅膏Amanita excelsaF155浸提液对根结线虫的致死率达96.67%,但发酵液仅为70.93%。粉迷孔菌Daedalea biennis F139的浸提液对小杆线虫的毒力最强,致死率达90.40%。松生拟层孔菌Fomitopsis pinicola F130的浸提液与裂褶菌Schizophyllum commune F107的浸提液和发酵液及小灰孢Lycoperdon pusillus F102的发酵液对水稻干尖线虫的致死率均超过95%。血红菇Russula sanguinea F204和大红菇R.alutacea F153的浸提液和发酵液对3种植物线虫的致死率均超过85%,而对小杆线虫的毒力较弱。  相似文献   

20.
In two experiments in the Wageningen Rhizolab with potato cv. Mentor planted in soils with or without potato cyst nematodes (Globodera pallida, W) the number of roots per cm2 was observed two weekly by video camera, in horizontally placed minirhizotrons at depths varying from 5 to 100 cm. In both experiments initial root growth was more rapid in the top soil of the uninfected soil. In the first experiment under optimal water supply, root formation continued longer in the top 30 cm of infested soil leading to twice as many roots at the end of the growing season as in uninfested soil. In the subsoil from 30 to 100 cm, however, root formation was strongly reduced by cyst nematodes leading to an uneven distribution of roots throughout the profile. In the second experiment potato cyst nematodes only increased rooting in the top soil with reduced irrigation. Potato cyst nematodes did not affect the water use efficiency of the crop whereas reduced irrigation increased water use efficiency by about 22%. Without potato cyst nematodes the soil profile was depleted of mineral nitrogen until a depth of 1 m whereas with high initial population densities no nitrogen was taken up in the subsoil between 30 and 100 cm. The spational heterogenity of roots and nitrogen in the soil is an important mechanism of damage. This finding may lead to improved cultural practices and breeding for tolerance.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号