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1.
短毛独活精油提取及抑菌作用研究   总被引：3，自引：0，他引：3  
用石油醚提取获得短毛独活精油,采用生长速率法测试短毛独活精油的杀菌活性。结果表明:短毛独活精油对12种供试真菌均具有不同程度的抑菌作用,其中对小麦纹枯病菌的抑制率最强,达到100%;其次是油菜菌核病菌、辣椒疫霉病菌,达到80%以上;而对玉米大斑病菌、稻瘟病菌的抑制率相对较低。  相似文献   

2.
在昆明烟区5个红花大金元种植点选取具有典型黑胫病症状的烟样16个,采用组织分离法分离、燕麦培养基培养和光学显微镜鉴定,结果表明,在昆明地区发生黑胫病样症状的病株,不一定都仅仅是感染黑胫病病原菌,既有单一病原菌感染的典型黑胫病,也有黑胫病伴随的根黑腐病,还有可能是发生了立枯病、根黑腐病或是其他病原菌感染,其中有的是单一病原危害造成、有的是2~3种病菌混生导致.因此,根据烟草黑胫病样病害发病条件、发病规律,结合当前的防治药剂,建议制定以病原菌鉴定为依据,采取农业防治、生物防治和化学防治相结合的综合防治措施则可得到切实的防治.  相似文献   

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4.
草莓红中柱根腐病原致病性及杀菌剂毒力测定   总被引：1，自引：0，他引：1  
为探究草莓红中柱根腐病的病原菌类型及筛选防治草莓红中柱根腐病适用药物,对皖北草莓种植区红中柱根腐病进行了调查、取样,并在室内进行病原菌分离、鉴定及致病性测定;同时,采用杀菌剂平板生物量法测定5种杀菌剂对草莓根腐病原菌的抑制中浓度EC50。结果表明,皖北草莓红中柱根腐病优势病原菌为立枯丝核菌及尖孢镰刀菌两种类型,58％雷多米尔EC50值为464．05,抑菌率最高;其次为95％溴菌清、50％异菌脲和80％乙磷铝;72．2％霜霉威EC50值为5715．58,抑菌率最差,EC50值大小为72．2％霜霉威〉80％乙磷铝〉50％异菌脲〉95％溴菌清〉58％雷多米尔。  相似文献   

5.
INTRODUCTION Plants have defense mechanisms against patho-gen infection by inducing systemic resistance in re-sponse to localized pretreatment with biological cotrol agents, thus making them resistant to subsequpathogen infection (Caruso et al., 1999; Hammschmidt, 1999; Mohammadi and Kazemi, 2002; yada et al., 1995; Pozo et al., 2002; Ray et al., 199Biological control of plant pathogens has receivmuch more attention. It is well known that plants amicroorganisms symbiosis is a defense m…  相似文献   

6.
Naturally fermented pickles harbour many lactic acid bacteria (LAB). Forty-three LAB strains with conjugated linoleic acid (CLA)-producing ability were isolated from three naturally fermented pickle brines. Of these isolates, lp15 identified as Lactobacillus plantarum by API 50 CHL system and full-length 16S rDNA sequence analysis exhibited the highest CLA-producing ability (26.1% conversion) at 48 h in de Man Rogosa Sharpe (MRS) broth in the presence of 100 μg/ml of linoleic acid (LA). Compared to other strains, L. plantarum strain lp15 showed the highest tolerance upon increased levels of LA in the medium, i.e., up to 600 μg/ml. This strain converted about 25% of LA into CLA isomers [predominantly cis-9, trans-11 CLA (9-CLA) and trans-10, cis-12 CLA (10-CLA)], of which 75% was 9-CLA. Interestingly, though the conversion rate of LA into CLA by lp15 remained stable between 100 to 600 μg/ml LA levels in the medium, it dropped sharply at 1000 μg/ml. Taken together, the lp15 strain displayed relatively high LA tolerance with higher conversion rate, which implies that this strain is a valuable candidate for enhancing the CLA content in food-sources like pickles.  相似文献   

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8.
从唐山师范学院花房中采集菘蓝根腐病病根并对其进行了病原菌的分离、纯化和鉴定及不同浓度、不同分子量的壳聚糖对菘蓝根腐病病原菌的室内抑菌作用。结果表明：分离纯化得到致病菌经鉴定为半知菌亚门（Deuteromycotina）、丝孢纲（Hyphomycetes）,丛梗孢目（Stilbellales）、瘤座孢科（Tuborculadales）、镰刀属（Fusarium）真菌。在一定浓度范围内,分子量为3KD、50KD的壳聚糖随着浓度的提高,其抑菌效果也逐渐增强,6mg／ml的效果最好;分子量为150KD时,3mg／ml的效果最好;在一定分子量范围内,除0．75mg／ml的浓度外,随着壳聚糖分子量的提高,其抑菌效果也逐渐增强,分子量150KD的效果最好;本试验中,最大抑菌率为61％。  相似文献   

9.
The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus ofGlomus intraradices and/or infection with pathogenic strain ofPhytophthora capsici, and the biological control effect ofG. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated withG. intraradices (Gi), (2) plants pre-inoculated withG. intraradices and then infected withP. capsici (Gi+Pc). (3) plants infected withP. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal colonization rate was reduced by about 10% in pathogen challenged plants. Root mortality caused by infection ofP. capsici was completely eliminated by pre-inoculation with antagonisticG. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only 21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase (PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9% in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major POD isozymes (45000, 53000 and 114000) were present in Pc-treated roots, while two major bands (53000 and 114000) and one minor band (45000) were present in spectra of Gi+Pc-treated roots, the 45000 POD isozyme was significantly suppressed byG. intraradices, suggesting that the 45000 POD isozyme was induced by the pathogen infection but not induced by the antagonisticG. intraradices. A 60000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the inoculation of antagonisticG. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper plants infected byP. capsici. The results suggested thatG. intraradices is a potentially effective protection agent againstP. capsici. Project supported by Korea Science and Engineering Foundation (KOSEF) through the Agricultural Plants Stress Research Center (APSRC) at Chonnam National University, Korea  相似文献   

10.
核盘菌多聚半乳糖醛酸酶基因的克隆及hpRNAi载体的构建   总被引：1，自引：0，他引：1  
多聚半乳糖醛酸酶是核盘菌致病力发挥作用的关键酶。本研究用PCR的方法从核盘菌基因组DNA中扩增出多聚半乳糖醛酸酶（PG5）基因片段,再以扩增出的PG5基因片段作为模板设计引物扩增出一个相应较小的片段。将两个PG5基因片段反向插入到植物表达载体2300 sn的35S启动子和nos终止子之间,构建出可转录表达出发夹RNA结构的组成型油菜RNA干扰载体,为今后油菜利用RNA干扰抗菌核病的基因工程研究奠定了基础。  相似文献   

11.
Chinese soft-shelled turtles (Trionyx sinens) in culture farms using an artificial warming system in Zhejiang, China,often show typical signs of white-spot disease such as white spots on their bodies, skin lesions, anorexia and eventually death. The sick turtles were mostly 5～80 g in weight. A suspected fungai pathogen was isolated from the sick turtles and verified as Pae-cilomyces lilacinus by sequence analysis of the internal transcribed spacer (ITS) of its ribosomal DNA (rDNA). Detailed mor-phological examinations were also conducted to confirm the white-spot disease.  相似文献   

12.
Chinese soft-shelled turtles (Trionyx sinens) in culture farms using an artificial warming system in Zhejiang, China, often show typical signs of white-spot disease such as white spots on their bodies, skin lesions, anorexia and eventually death. The sick turtles were mostly 5~80 g in weight. A suspected fungal pathogen was isolated from the sick turtles and verified as Paecilomyces lilacinus by sequence analysis of the internal transcribed spacer (ITS) of its ribosomal DNA (rDNA). Detailed morphological examinations were also conducted to confirm the white-spot disease.  相似文献   

13.
The phytochrome B (PHYB) gene of Arabidopsis thaliana was introduced into cotton through Agrobacterium tumefaciens. Integration and expression of PHYB gene in cotton plants were confirmed by molecular evidence. Messenger RNA (mRNA) expression in one of the transgenic lines, QCC11, was much higher than those of control and other transgenic lines. Transgenic cotton plants showed more than a two-fold increase in photosynthetic rate and more than a four-fold increase in transpiration rate and stomatal conductance. The increase in photosynthetic rate led to a 46% increase in relative growth rate and an 18% increase in net assimilation rate. Data recorded up to two generations, both in the greenhouse and in the field, revealed that overexpression of Arabidopsis thaliana PHYB gene in transgenic cotton plants resulted in an increase in the production of cotton by improving the cotton plant growth, with 35% more yield. Moreover, the presence of the Arabidopsis thaliana PHYB gene caused pleiotropic effects like semi-dwarfism, decrease in apical dominance, and increase in boll size.  相似文献   

14.
2010年2月下旬,从南阳市超市购买的苹果中,发现感染皮孔斑点病的病果,从病果上随机采集病斑,经表面消毒后将病斑置于PDA平板上进行病原菌分离.从19个病斑中共分离获得17株形态相同的链格孢属真菌,经单孢纯化后对代表性致病菌株AP-5-3进行病原学鉴定.根据病原菌的形态特征及其核糖体基因内转录间隔区(rDNA-ITS)序列分析,将菌株AP-5-3鉴定为细交链孢菌(Alternaria alternata).该菌的最适生长温度为28℃,最适合生长pH为6.5.本文对苹果皮孔斑点病的病因进行了讨论.  相似文献   

15.
从关白附（Aconitum Coreanum（Levl.）Rapaics）中分离出内生菌共29株,通过TLC检测筛选出2株可能产生生物碱类成分的内生菌.对筛选出的2株内生菌株的发酵培养物分别以纸片法和MTT法进行抑菌和细胞毒活性测定.实验结果显示,2个内生菌株发酵产物对金黄色葡萄球菌、大肠杆菌具有良好的抑菌作用,对肝癌细胞SMMC-7721、胃癌细胞SGC-7901具有良好的细胞毒活性.通过16S rDNA基因序列分析,2株内生菌分别被鉴定为类芽孢杆菌属和芽孢杆菌属细菌.  相似文献   

16.
In this study, plant growth-promoting rhizobacteria (PGPR) were evaluated as potential biocontrol agents against postharvest pathogens of apple fruits. In vitro bioassays revealed that, out of 30 isolates screened, isolates APEC136 and APEC170 had the most significant inhibitory effects against the mycelial growth of several fungal pathogens. Analysis of 16S ribosomal RNA (rRNA) sequences identified the two effective isolates as Paenibacillus polymyxa and Bacillus subtilis, respectively. The two strains showed greater growth in brain-heart infusion broth than in other growth media. Treatment of harvested apples with suspensions of either strain reduced the symptoms of anthracnose disease caused by two fungal pathogens, Colletotrichum gloeosporioides and Colletotrichum acutatum, and white rot disease caused by Botryosphaeria dothidea. Increased productions of amylase and protease by APEC136, and increased productions of chitinase, amylase, and protease by APEC170 might have been responsible for inhibiting mycelial growth. The isolates caused a greater reduction in the growth of white rot than of anthracnose. These results indicate that the isolates APEC136 and APEC170 are promising agents for the biocontrol of anthracnose and white rot diseases in apples after harvest, and suggest that these isolates may be useful in controlling these diseases under field conditions.  相似文献   

17.
INTRODUCTION In some coastal cities of China, municipal solidwaste (MSW) is ultimately landfilled at seashorezones with cheaper land-value and less disturbance tonearby residents. These seashore landfills wereusually constructed without appropriate liners toprevent percolation of leachate into underlyingaquifers. Dramatic hydrochemical changes in theseaquifers have been detected as a result of the highorganic load of leachate. Furthermore, these aquiferswere inevitably infiltrated by sea…  相似文献   

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19.
A novel member of extremely halophilic archaea, strain AJ2, was isolated from Ayakekum Lake located in Altun Mountain National Nature Reserve of Xinjiang Uygur Autonomous Region in China. The strain AJ2 requires at least 10% (w/v) NaCl and grows 10% to 30% (optimum at 20%). Phylogenetic analysis based on 16S rDNA sequence  相似文献   

20.
通过玉米自交系478试验田系统观察,今年玉米青枯病在其上有所发生。分析了该病与栽培措施(施N水平、种植密度等)和气象因素的关系。并初步鉴定其主要病原菌为F·graminearum,同时提出了该病的防治建义。  相似文献   

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