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1.
一株产几丁质酶、抑真菌的侧孢芽孢杆菌   总被引:2,自引:0,他引:2  
从524株芽孢杆菌中筛选出一株几丁质酶活力高的侧孢芽孢杆菌1.864菌株。研究表明该菌对小麦赤霉菌等6种病原真菌具有明显的抑制作用。通过几丁质酶抑制剂以及酶活力变化对抑制真菌活性的相关研究,初步认为该菌株的抑菌物质为几丁质酶。生物测定表明1.864的几丁质酶粗酶对蚊幼具有较高的活性,同时对Bt制剂杀虫活性具有明显的增效作用。  相似文献   

2.
为了明确重寄生真菌盾壳霉Coniothyrium minitans产生的抗真菌物质(antifungal substances,简称AFS)的基本特性,本文从盾壳霉MCD培养物滤液的抑菌谱、热稳定性、酸碱稳定性及紫外线照射稳定性4个方面展开研究。研究结果表明,盾壳霉AFS对核盘菌Sclerotinia sclerotiorum、三叶草核盘菌S.trifoliorum、小核盘菌S.minior等10种真菌菌丝生长具有较强的抑制作用。AFS具有较强的热稳定性,盾壳霉MCD培养物滤液经120℃处理30 min后,对核盘菌仍具有抑菌活性(抑菌率为49.5%)。不同环境pH对AFS的抑菌活性具有不同的影响,pH值为7,AFS对核盘菌菌丝生长抑制活性最强。此外,环境pH也影响AFS的稳定性,在较宽的pH值范围内(1~14),尤其是在酸性条件下(pH 1~6),AFS活性稳定(抑菌率为81.1%~76.4%);AFS对紫外线照射具有一定的稳定性。盾壳霉抗真菌物质对外界环境具有很好的稳定性,这对于应用盾壳霉的抗真菌物质来防治油菜菌核病是非常有利的。  相似文献   

3.
粉红螺旋聚孢霉Clonostachys rosea是一种重要的植物病原生防真菌。本研究测定了不同地理来源的42株粉红螺旋聚孢霉菌株对核盘菌Sclerotinia sclerotiorum菌核的寄生能力,以及菌株几丁质酶和β-1,3-葡聚糖酶的活性,同时测定了不同菌株对番茄灰霉病菌Botrytis cinerea的拮抗作用以及对番茄果实灰霉病的防治效果。结果表明,不同来源的粉红螺旋聚孢霉菌株对核盘菌菌核均有一定的寄生能力,45.2%的菌株寄生能力达到4级,β-1,3-葡聚糖酶和几丁质酶活性与其寄生能力呈极显著正相关。研究发现,粉红螺旋聚孢霉菌株对番茄灰霉病菌有一定的拮抗作用,抑制率最高可达78.4%;HN-56、STG-21-1、GS6-1等菌株对离体番茄果实灰霉病的防效达到75%以上,显示出良好的生防潜力。本研究为丰富植物真菌病害生防资源和高效粉红螺旋聚孢霉生防制剂的研发奠定了基础。  相似文献   

4.
生防细菌PA2101和PG3402抑菌和促生特性的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
以本实验室分离的在烟草生产上具有较大生防潜力的铜绿假单胞杆菌PA2101和格拉纳达假单胞杆菌PG3402为对象,测定了这2株细菌的抑菌活性及促生特性。试验结果表明,菌株PA2101和PG3402对烟草根腐病、烟草赤星病、小麦纹枯病、芝麻茎点枯病和地黄轮纹病等多种作物常见病害的病原菌具有较强的拮抗作用;2株菌株的无菌发酵滤液能使烟草疫霉和根串珠霉菌丝生长畸形、抑制根串珠霉分生孢子的萌发。菌株PA2101和PG3402产生对2种病原菌有抑制作用的挥发性物质。抑菌特性检测结果表明,菌株PA2101和PG3402均能产生蛋白酶、纤维素酶和β-1,3-葡聚糖酶等胞外酶,PA2101还能分泌几丁质酶。另外,2株菌株能合成抑菌活性物质氢氰酸(HCN)。抗生素合成基因检测结果发现,菌株PA2101和PG3402均包含吩嗪-1-羧酸(Phenazine-1-carboxylic acid,PCA)合成基因,PG3402还含有2,4-二乙酰基间苯三酚(2,4-diacetylphloroglucinal,DAPG)合成基因。促生物质的检测结果表明,菌株PA2101和PG3402均可产生嗜铁素和生长素(IAA),且具备溶磷特性。综上所述,菌株PA2101和PG3402抑菌谱较广,产生多种抑菌和促生物质,含有合成PCA和DAPG的基因,可用于烟草病害的防控。  相似文献   

5.
 本研究通过平板透明圈法筛选获得一株具有几丁质酶活性的生防细菌CAB-1,该菌株对番茄灰霉病菌等多种病原真菌表现较强的拮抗活性。通过生理生化、16S rDNA和gyrB基因序列测定,将菌株CAB-1鉴定为萎缩芽胞杆菌(Bacillus atrophaeus)。对菌株CAB-1全基因组序列进行分析和功能预测,发现该菌株存在2个几丁质酶编码基因chit1和chit2。通过PCR技术从菌株CAB-1中克隆出这两个几丁质酶的编码基因并在大肠杆菌中表达,其原核表达产物均表现几丁质酶活性,其中chit1的原核表达产物能够显著抑制灰霉菌分生孢子的萌发。对其原核表达条件进行优化,发现在30℃下振荡培养24 h,IPTG浓度为0.2~1.0 mmol/L时,其蛋白表达量最高。  相似文献   

6.
为建立短小芽胞杆菌Bacillus pumilus DX01菌株的Tn5转座突变株抑菌活性的高效筛选体系,采用发酵液平板抑菌法研究了各突变株发酵液对稻瘟病菌Magnaporthe grisea生长的影响,并测定了目标突变株的几丁质酶和蛋白酶活性及发酵液对稻瘟病菌分生孢子萌发的抑制率。从2 633个突变株中筛选出6个抑菌活性较对照菌株DX01显著变化的突变株。对照DX01发酵液对真菌孢子萌发的抑制率为36%,而突变株Tn5-901和Tn5-194则分别为96%和3%,抑菌活性与对照的差异达到极显著水平。其余4个突变株的几丁质酶、蛋白酶活性多重比较结果与发酵液平板抑菌结果并不完全一致,但发酵液平板抑菌法简单、高效,适用于短小芽胞杆菌突变株的抑菌活性初筛。  相似文献   

7.
为了提高伯克氏菌Burkholderia vietnamiensis的生防能力,通过Tn5转座子介导,将其携带的来自枯草芽孢杆菌Bacillus subtilis的几丁质酶基因整合到野生伯克氏菌B418染色体DNA上,获得工程菌株B418-37。对获得的转化子进行Southern杂交和几丁质酶活性检测,结果证实几丁质酶编码基因已整合到伯克氏菌B418-37染色体DNA上并能表达几丁质酶。生物学特性研究发现几丁质酶基因整合到伯克氏菌染色体中,没有影响野生菌的解磷、解钾、固氮及其在植物根际的定殖能力。平板抑菌试验和温室盆栽试验显示,与野生型相比,该工程菌株对多种病原真菌的抑菌效果增强,说明几丁质酶在植物病害的防治中具有重要作用。上述结果说明通过染色体整合几丁质酶基因是获得多功能生防工程菌的有效途径之一。  相似文献   

8.
为探究斑蝥素衍生物对核盘菌Sclerotinia sclerotiorum (Lib.) de Bary的抑菌活性和抑菌机理,测定了5 种3-卤苯基芳香胺取代去甲斑蝥素 ( BY 、 BY-1 、 BY-2 、 BY-3 和 BY-4 ) 对核盘菌的菌丝生长和菌核形成的影响,采用离体叶片法测定了其对油菜菌核病的相对防效;并通过测定斑蝥素衍生物处理菌体后菌丝形态、菌体相对电导率、丙二醛含量、还原糖和可溶性蛋白含量、几丁质酶活性及草酸含量等分析斑蝥素衍生物的抑菌机理。结果显示:5种斑蝥素衍生物对核盘菌均有显著的抑制作用, BY 、 BY-1 、 BY-2 、 BY-3 和 BY-4 的EC50值分别为37.6、8.78、6.45、12.2和50.4 μg/mL。其中, BY-2 对核盘菌菌核形成的抑制作用最强,在12.5 μg/mL时的抑制率达86.52%;在100 μg/mL时其对离体叶片上油菜菌核病的相对防效达到97.71%。表明在苯环C-3’位引入氯原子可以显著提高化合物对油菜菌核病菌的抑菌活性。用斑蝥素衍生物处理核盘菌后,菌丝体表面粗糙,或脱水枯萎,或畸形膨大;细胞膜通透性增加,菌体内还原糖和可溶性蛋白含量降低,几丁质酶活性提高,草酸含量显著降低。表明斑蝥素衍生物能够有效抑制油菜菌核病菌,为生物源杀菌剂的开发提供了理论依据。  相似文献   

9.
Bt棉有效控制了棉田主要害虫棉铃虫(Helicoverpa armigera),然而原来处于次要地位的刺吸式口器害虫盲蝽(Heteroptera:Miridae)为害逐年加重,目前对绿盲蝽(Apolygus lucorum Meyer-Dür)有效的抗虫基因未见报道。本研究以本实验室保存的Bt杀虫基因和菌株为材料,对绿盲蝽进行杀虫活性筛选。利用本实验室先前克隆的Mtx类杀虫基因cry15Aa表达产物进行绿盲蝽杀虫活性测定,研究结果显示Cry15Aa蛋白对绿盲蝽具有一定的杀虫活性。通过杀虫活性测定,获得对绿盲蝽有效的Bt菌株20株;对这些菌株表达蛋白进行质谱鉴定,LC-MS/MS质谱鉴定结果显示,这些菌株可能含有Cry1Aa、Cry1Ab、Cry1Ac、Cry1Ae、Cry1Af、Cry1Ag、Cry1Ah、Cry1Ba、Cry1Be、Cry8Ha等十余种对鳞翅目、鞘翅目害虫有杀虫活性的蛋白片段,并且有4株Bt菌株样品中检出了Mtx类杀虫蛋白Cry15Aa的片段。但是进一步基因鉴定结果表明,这4株菌株并不含有cry15Aa全长基因,推测这些菌株中含有Cry15类的新基因。上述研究结果表明这些菌株中可能存在对盲蝽有效的新型杀虫蛋白。本研究在发现了cry15Aa基因所表达的蛋白对绿盲蝽具有杀虫活性的同时,获得了对绿盲蝽具有杀虫活性的Bt新菌株,对绿盲蝽的生物防治具有重要的意义。  相似文献   

10.
从几十种作物的根际和叶围分离获得350株微生物,其中细菌和放线菌分别为200株和150株。对所有这些分离物进行了抑制真菌试验和几丁质酶活性测定。在抑菌试验中,以棉花枯萎病菌、棉花黄萎病菌、黄瓜枯萎病菌,及西瓜枯萎病菌作为供试病原菌,有96个分离物对其中的一种或一种以上的病原菌有抑制作用,其中18个分离物对这4种病原菌都具有强烈的抑制作用。在几丁质酶活性方面,10%的细菌和40%的放线菌都能不同程度地产生几丁质酶。有些菌株几丁质酶活性强,抑菌作用也明显,有些菌株几丁质酶活性弱,抑菌作用弱或无作用,少数菌株几丁质酶活性强,但却无抑菌作用。用几丁质酶液处理病原菌孢子,其萌发率和芽管长度比对照显著降低  相似文献   

11.
Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.  相似文献   

12.
We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.  相似文献   

13.
Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.  相似文献   

14.
《干旱区科学》2014,(6):782-782
正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad  相似文献   

15.
Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.  相似文献   

16.
Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F 3, F 4 and F 5, but not in F 1 and F 2 that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F 1 and F 2 in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.  相似文献   

17.
Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.  相似文献   

18.
19.
A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVYN strain and six to the PVYO strain. No PVYC was found. Two other isolates reacted serologically like PVYO, but were unable to elicit a hypersensitive response from the Nytbr gene and probably represent the PVYZ group. At the molecular level, these two isolates showed a combination of both PVYO and PVYN and could be recombinants of these strains. Another isolate reacted serologically like PVYO, but induced vein necrosis in tobacco, like PVYN-Wilga. Some PVYN isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVYNTN group. The PVYNTN, PVYN-Wilga and PVYZ groups probably represent pathotypes within strains PVYN and PVYO, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.  相似文献   

20.
The phenology of the autumn leafroller,Syndemis musculana, a local pest of apple, was studied in order to forecast larval emergence. From 1983–1986, peak flight as determined with sexpheromone traps was always between 13–18 May. The duration of embryonic development was determined at various constant temperatures and used to estimate the periods of egg hatch in these four years. Each year, most eggs should have hatched in the second decade of June.Differences in attack rates between apple cultivars seem to be explained largely by the variation in picking time. Larvae are only half grown at the beginning of harvest (cv. James Grieve), and have gone into hibernation when the latest variety (cv. Golden Delicious) is picked. Moreover, the varieties Cox's Orange Pippin and Belle de Boskoop, picked about half time, are liable to receive additional damage by caterpillars brought with the picked fruits into storage.Various hymenopterous parasites were reared from caterpillars. As the only leafroller in the orchard which hibernates as mature larva,S. musculana may promote winter survival of some parasitoids, like the eulophidColpyclypeus florus.Samenvatting De fenologie van de herfstbladroller (Syndemis musculana Hübner), een incidentele plaag op appel, werd nader bepaald met het doel het uitkomen van de eieren te kunnen voorspellen. In 1983–1986 viel de piekvlucht, bepaald met behulp van feromoonvallen, steeds tussen 13 en 18 mei.De ontwikkelingsduur van de eieren bij verschillende constante temperaturen werd gebruikt om de periode van uitkomen te schatten. De meeste eieren zullen ieder jaar in de eerste helft van juni uitkomen.Geconstateerde verschillen in schade tussen appelrassen blijken goeddeels terug te voeren op verschillen in pluktijdstip. De rupsen van de herfstbladroller zijn pas half-was als de eerste appels eind augustus geplukt worden, terwijl tegen het einde van de oogst begin oktober de meeste al in winterslaap zijn. Met name tussentijdse rassen, als Cox's Orange Pippin and Schone van Boskoop, lopen extra schade op doordat grotere rupsen met de geplukte vruchten in de kist terecht komen.Uit de rupsen werden negen, al van andere boomgaardbladrollers bekende, sluipwespen gekweekt, Omdat deze bladrollersoort, als enige in de boomgaard, als volgroeide rups overwintert, lijkt zij bij uitstek geschikt als winterwaard.This study was carried out at the Experimental Orchard De Schuilenburg, Schuilenburg 3, 4041 BK Kesteren, the Netherlands, to which address correspondence should be addressed.  相似文献   

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