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1.
阔叶十大功劳炭疽病初报   总被引:3,自引:0,他引:3  
 A new leaf spot disease of Mahonia healei was found in Guangxi China, which was one of the limitations for the growth of M. healei. Based on the morphology, pathogenicity and the analysis of sequences of ribosome rDNA-ITS, the pathogen of M. healei anthracnose disease was identified as Colletotrichum gloeosporioides (Penz.)Sacc.  相似文献   

2.
 Balsam pear bacterial wilt was observed in Nanning, Guangxi, China. Based on bacteriological identification, pathogenicity tests and 16S rDNA sequencing analysis, the pathogen was identified as Ralstonia solanacearum (Smith) Yabuuchi et al. This is the first report of R. solanacearum causing bacterial wilt on balsam pear in China.  相似文献   

3.
小麦-滨麦易位系M8657-1抗条锈病基因遗传分析和分子标记   总被引:3,自引:0,他引:3  
 M8657-1, one of the wheat translocation lines derived from Leymus mollis Trin. Hara, is possessed of effective resistance at all stages to Su-ll and other dominant races of Puccinia striiformis f. sp. tritici in China. Seedlings of the parents, F1, and F2 progeny derived from the cross of M8657-1 (resistant) Mingxian169 (susceptible) were inoculated with Su-ll in greenhouse to identify and map the probable new stripe rust resistance gene. The results suggested that the stripe rust resistance in M8657-1 was conferred by a pair of recessive genes. Simple sequence repeat (SSR) technique was used to detect molecular marker associated with the resistance gene:208 pairs of wheat SSR primers were used to screen the two parents, as well as resistant and susceptible bulks and then three SSR markers were selected for genotyping the F2 population. The geue, temporarily designated as YrLml, was found to be located on the chromosome 7DL and flanked by three SSR markers GDM67, WMC150 and WMC671, with the genetic distance of 5.0, 9.7 and 11.8cM, respectively.  相似文献   

4.
 Fusarium oxysporum is one of the most important phytopathogens and cause Fusarium wilt disease in cucumber, watermelon and melon, etc.In this study, a pair of species-specific primers Fc-1 and Fc-2 was synthesized based on differences in internal transcribed spacer sequences of Fusarium genus.With the primers, a specific 315 bp PCR product was amplified from five F.oxysporum isolates isolated from cucumber, watermelon and melon, infected cucumber and watermelon tissues, while no product was obtained from other fourteen fungi, healthy cucumber and watermelon tissues.The detection sensitivity is 100 fg for genomic DNA of F.oxysporum and 1 000 spores/g soil for the soil pathogens.In contrast, the nested PCR with two pairs of primers(ITS1/ITS4 and Fc-1/Fc-2) increased the sensitivity by 100-fold.In addition, one-step PCR could also detect F.oxysporum in symptomless cucumber root of 7 dpi(days post inoculation) and in infected cucumber and watermelon tissues at the early stage of disease development.Therefore, the developed PCR-based method enabled rapid, sensitive and reliable detection of F.oxysporum.It also provides the detection method for early monitoring and diagnosis of the pathogen as well as the plant disease management guidance.  相似文献   

5.
土壤中烟草根黑腐病菌的实时定量PCR检测技术研究   总被引:1,自引:0,他引:1  
 Thielaviopsis basicola is a soil-borne plant pathogen which causes root rot disease in tobacco plants. Detection and monitoring of T. basicolain soil is of great significance to control this disease. Based on the differences in internal transcribed spacer (ITS) sequences of T. basicola and other fungal pathogens, a specific primer pair Tb1/Tb2 for T. basicolawas developed. The results showed that the primer pair gave a single amplicon of 330 bp from T. basicola and revealed no undesirable cross-reaction with other seven soil-borne pathogen isolates and three tobacco rhizosphere dominant fungi isolates. With a series of 10-fold genomic DNA dilutions of T. basicola, the detection limit of 1 pg/μL in conventional PCRand100 fg/μL in real-time quantitative PCR was achieved. With DNA from the soil inoculated with different numbers of T. basicola conidia, the detection limit was 10 conidia per reaction in conventional PCR and 0.4 conidia per reaction in real-time quantitative PCR.  相似文献   

6.
 Wheat blue dwarf(WBD) is a disease caused by phytoplasma and only reported from China. A fragment about 1.3 kb in protein translocation gene, secY was amplified by PCR from the total DNA of di-seased wheat sample with primer pair secYF/secYR, which was designed based on secY gene sequence of known 16SrI group members. Nucleotide acid sequence analysis of amplified fragment indicated that the length was 1 240 bp. A phylogenetic tree based on secY gene sequences was constructed and showed that wheat blue dwarf phytoplasma was clustered into the Candidatus Phytoplasma asteris, subgroup 16SrI-C. Wheat blue dwarf phytoplasma showed high homology with clover phyllody phytoplasma strains based on sequence comparison and phylogenetic analysis.  相似文献   

7.
蝴蝶兰软腐病中一种新致病菌的分离与鉴定   总被引:2,自引:0,他引:2  
 Soft rot disease often affects Phalaenopsis amabilis during the growing season. However, the pathogen of the disease is remaining poorly studied. In this study, bacterial strain R1 was isolated from soft rot tissues in Wuhan. The pathogenic, morphological, physiological, biochemical tests and 16S rDNA sequence analysis were carried out. The homology of 16S rDNA sequence between strain R1 and Pseudomonas grimontii was 99.72%, and its physiological and biochemical properties were also similar to those of Pseudomonas grimontiis. All these evidences indicated that strain R1 could be identified as a novel strain of Pseudomonas grimontii. The pathogenicity of the novel isolate was proved according to the Koch's postulates. This is the first report that Pseudomonas grimontii can cause soft rot disease of Phalaenopsis amabilis.  相似文献   

8.
High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial aspects of the AC-cooled greenhouse as compared to the evaporative cooled(EV-cooled)greenhouse in winter and summer seasons.Two quonset single-span prototype greenhouses were built in the Agriculture Experiment Station of Sultan Qaboos University,Oman,with dimensions of 6.0 m long and 3.0 m wide.The AC-cooled greenhouse was covered by a rockwool insulated polyethylene plastic sheet and light emitting diodes(LED)lights were used as a source of light,while the EV-cooled greenhouse was covered by a transparent polyethylene sheet and sunlight was used as light source.Three cultivars of high-value lettuce were grown for experimentation.To evaluate the technical efficiency of greenhouse performance,we conducted measures on land use efficiency(LUE),water use efficiency(WUE),gross water use efficiency(GWUE)and energy use efficiency(EUE).Financial analysis was conducted to compare the profitability of both greenhouses.The results showed that the LUE in winter were 10.10 and 14.50 kg/m2 for the AC-and EV-cooled greenhouses,respectively.However,the values reduced near to 6.80 kg/m2 in both greenhouses in summer.The WUE of the AC-cooled greenhouse was higher than that of the EV-cooled greenhouse by 3.8%in winter and 26.8%in summer.The GWUE was used to measure the total yield to the total greenhouse water consumption including irrigation and cooling water;it was higher in the AC-cooled greenhouse than in the EV-cooled greenhouse in both summer and winter seasons by almost 98.0%–99.4%.The EUE in the EV-cooled greenhouse was higher in both seasons.Financial analysis showed that in winter,gross return,net return and benefit-to-cost ratio were better in the EVcooled greenhouse,while in summer,those were higher in the AC-cooled greenhouse.The values of internal rate of return in the AC-and EV-cooled greenhouses were 63.4%and 129.3%,respectively.In both greenhouses,lettuce investment was highly sensitive to changes in price,yield and energy cost.The financial performance of the AC-cooled greenhouse in summer was better than that of the EV-cooled greenhouse and the pattern was opposite in winter.Finally,more studies on the optimum LED light intensity for any particular crop have to be conducted over different growing seasons in order to enhance the yield quantity and quality of crop.  相似文献   

9.
小麦抗白粉病基因Pm6的微卫星标记鉴定   总被引:3,自引:0,他引:3  
 Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is a prevalent disease worldwide. Breeding and planting resistance cultivars have been proved effective and environmental friendly for control of the disease. To develop easily used PCR-based markers in marker assisted selection (MAS) for Pm6, a dominant powdery mildew resistance gene in wheat, 25 microsatellite markers on chromosome 2BL in wheat were screened between susceptible parent Yumai13 and resistance parent Timgalen carrying Pm6. F2 population derived from Yumai13 and Timgalen was further analyzed by the marker Xgwm501. The results indicated that Xgwm501 was a co-dominant marker linked to Pm6 gene at a distance of 14.8 cM. 29 Pm-carrying varieties were tested by the marker Xgwm501 and only those carrying Pm6 showed 117 bp resistance specific band. This marker is proved to have high practicability and can be used in MAS of Pm6 gene in wheat breeding programs.  相似文献   

10.
川芎茵核病的症状及病原菌鉴定   总被引:1,自引:0,他引:1  
罗玲  黄云  王靖  何苗  万英 《植物病理学报》2009,39(5):532-535
 Symptoms of sclerotinia stem rot of Ligusticum chuanxiong were observed and the causal agent of the disease was identified. The results showed that the symptoms of this disease began with the formation of dark brown hygrophanous splotch on the basal leaves, followed by the appearance of dark brown circular spot on the basal stem. Finally, the whole plant stoped growing and died. White mycelium and/or sclerotia were formed under moisturized conditions. On PDA medium, the pathogen of this disease formed brown sclerotia with various shapes and 2-5 mm in diameter. The diameter of apothecia was 0.3-0.8 cm and the length of stipes was 2-8 cm. Asci were columniform in shape and (100-135)×9μm in size, each containing 8 ascospores sized by (6-12) μm×(3-7)μm. No asexual spore formation was observed. Based on the morphological characteristics and the sequence of ribosomal DNAITS, the pathogen was identified as Sclerotinia sclerotiorum (Lib.) de Bary.  相似文献   

11.
A new disease of tomato plants with typical phytoplasma disease symptoms such as stunting, yellows, auxiliary shoot proliferation and phyllody was observed in Yunnan Province, southwest China in 2011. By a nested-PCR, phytoplasma were detected using the phytoplasma universal primers specific for 16S rDNA. The results of the 16S rDNA sequencing, computer-simulated RFLP patterns and phylogenetic analysis indicated that the phytoplasma associated with the diseased tomato plants belongs to subgroup A of the peanut witches’-broom group. This is the first report of a 16SrII-A phytoplasma associated with a new tomato disease in China. This new disease was named tomato yellows.  相似文献   

12.
ABSTRACT In an attempt to physically protect greenhouse tomato plants from the powdery mildew fungus Oidium neolycopersici, we developed a new electrostatic spore precipitator in which a copper wire conductor is linked to an electrostatic generator and covered with a transparent acrylic cylinder (insulator). The conductor was negatively charged by the generator, and the electrostatic field created by the conductor was used to dielectrically polarize the insulator cylinder. The dielectrically polarized cylinder also produced an electrostatic force without a spark discharge. This force was directly proportional to the potential applied to the conductor and was used to attract conidia of the pathogen. The efficacy of this spore precipitator in protecting hydroponically cultured tomato plants from powdery mildew was evaluated in the greenhouse. The hydroponic culture troughs were covered with a cubic frame installed with the spore precipitator, and the disease progress on precipitator-guarded and unguarded seedlings was traced after the conidia were disseminated mechanically from inoculum on tomato plants. Seedlings in the guarded troughs remained uninfected during the entire experiment, in spite of rapid spread of the disease to all leaves of the unguarded seedlings.  相似文献   

13.
Clavibacter michiganensis subsp. michiganensis (Cmm) is a quarantine organism in Europe and in many other countries. It is one of the most severe bacterial pathogens affecting tomato. Screening tomato plants for their resistance level to Cmm requires a large amount of space under quarantine conditions and is therefore costly. This project developed a new inoculation protocol on in vitro tomato plants to facilitate a more economic and higher throughput disease screening. A new method using the PathoScreen system was tested to localize green fluorescent protein-tagged Cmm in planta and to quantify the pathogen based on the percentage of corrected GFP (cGFP%). The system was sensitive in detecting the GFP-tagged Cmm in the shoots, but in the roots a high autofluorescence masked detection and thus sensitivity of the assay. The in vitro protocol was tested on several wild relatives of tomato, which were previously screened in a greenhouse assay. The correlation between wilt symptoms in vitro and wilt symptoms in the greenhouse was overall moderate (= 0.6462). The protocol worked well in differentiating the two parents that were used in the mapping studies. This study shows that the in vitro protocol can be efficiently used for resistance breeding in many tomato genotypes.  相似文献   

14.
Tomato bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (CMM) is a highly destructive disease that has caused major economic losses in tomato production worldwide. In seeking disease management alternatives, the inhibitory activity of alkaloids extracted from the Red Imported Fire Ant was studied in the laboratory and the greenhouse. Piperidine and piperideine alkaloids each significantly inhibited CMM growth on nutrient agar plates. The inhibitory activity of piperidine alkaloids was stable at 4 ° C and 22 ° C for 12 weeks and at 54 ° C for 4 weeks. The growth of CMM was negatively correlated with the concentration of piperidine alkaloids in nutrient broth. In the greenhouse, piperidine alkaloids also significantly reduced the symptom development on two tomato cultivars, Better Boy and DRK7018F1. This is the first demonstration that piperidine and piperideine alkaloids from the Red Imported Fire Ant are highly inhibitory against a plant-pathogenic bacterium, viz. CMM. Piperidine alkaloids could provide satisfactory management of CMM bacterial canker on tomato seedlings in the greenhouse. Our findings may lead to the development of a new group of bactericides.  相似文献   

15.
 由粉虱传双生病毒引起的番茄曲叶病[1]在我国最初仅分布在海南、云南、广东和广西,自2006年上海市和浙江省先后在番茄上发现番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)以来,该病害蔓延迅速,在多个省份的番茄上暴发成灾[2]。引起番茄曲叶病害的病原较复杂,在我国其主要病原为TYLCV、中国番木瓜曲叶病毒(Papaya leaf curl China virus, PaLCuCNV)、中国番茄黄化曲叶病毒(Tomato yellow leaf curl China virus, TYLCCNV)、泰国番茄黄化曲叶病毒(Tomato yellow leaf curl Thailand virus, TYLCTHV)和台湾番茄曲叶病毒(Tomato leaf curl Taiwan virus, ToLCTWV)[2~5],而浙江省的主要病原为TYLCV和ToLCTWV。选育抗病品种是防治番茄黄化曲叶病最有效的手段。了解番茄品种对不同双生病毒的抗性,对因地制宜布局抗病品种具有重要意义。浙杂502、浙粉701、浙粉702是浙江省大规模种植的番茄品种,为了解这些品种对上述5种病毒的抗性,本研究利用5种病毒的侵染性克隆,在人工接种条件下,综合评定分析这3个番茄品种的抗病指标。  相似文献   

16.
A semi-closed greenhouse was used for sustainable tomato production and to investigate the effects of the prevailing climate conditions within this greenhouse on different plant parameters of tomatoes. Compared to conventionally cultivated tomato plants, the leaf area index, the number of trusses and the yield of marketable fruit of tomato plants exposed to the microclimatic conditions in the semi-closed greenhouse were significantly increased by 21, 11 and 31.9?%, respectively. Furthermore, the application of this new technology led to a significant increase in contents of lycopene (by 30?%), ß-carotene (by 40?%), phenolic compounds (25?%), titratable acids (by 8?%) and soluble solids (by 15?%) in tomatoes during the summer period. These results were attributed to higher photosynthetic activities, which predominantly occurred in the greenhouse with the semi-closed operation mode. Furthermore, the new technology can be seen as new horticultural approach to reduce the yield of blossom-end rot fruit by 75.2?%. This quality improvement was caused by higher levels of relative humidity, where this humidity states were also responsible for a reduction in the annual plant transpiration rate by 10?%.  相似文献   

17.
ABSTRACT Bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, continues to be a problem for tomato growers worldwide. A collection of nonpathogenic bacteria from tomato leaves plus P. syringae strains TLP2 and Cit7, P. fluorescens strain A506, and P. syringae pv. tomato DC3000 hrp mutants were examined in a greenhouse bioassay for the ability to reduce foliar bacterial speck disease severity. While several of these strains significantly reduced disease severity, P. syringae Cit7 was the most effective, providing a mean level of disease reduction of 78% under greenhouse conditions. The P. syringae pv. tomato DC3000 hrpA, hrpH, and hrpS mutants also significantly reduced speck severity under greenhouse conditions. The strains with the greatest efficacy under greenhouse conditions were tested for the ability to reduce bacterial speck under field conditions at locations in Alabama, Florida, and Ontario, Canada. P. syringae Cit7 was the most effective strain, providing a mean level of disease reduction of 28% over 10 different field experiments. P. fluorescens A506, which is commercially available as Blight-Ban A506, provided a mean level of disease reduction of 18% over nine different field experiments. While neither P. syringae Cit7 nor P. fluorescens A506 can be integrated with copper bactericides due to their copper sensitivity, there exist some potential for integrating these biological control agents with "plant activators", including Actigard. Of the P. syringae pv. tomato DC3000 hrp mutants tested, only the hrpS mutant reduced speck severity significantly under field conditions.  相似文献   

18.
无致病力青枯菌株对番茄青枯病的防治效果   总被引:14,自引:0,他引:14  
用紫外诱变法获得的青枯无致病力菌株ATm0 4 4和Asp0 6 1对致病菌没有直接的抑制作用 ;处理番茄后对青枯病产生抗性 ;两菌株可在番茄体内定殖并繁殖 ,移栽浸根是最佳的处理方法。盆栽试验结果表明 ,番茄经ATm0 4 4和Asp0 6 1处理后 ,分别较对照推迟 9和 7d发病 ,2 0d后的防效达 56 .7%和 53.4 %。田间小区试验结果表明 ,经ATm0 4 4和Asp0 6 1菌悬液浸根处理番茄 ,1 5d后对青枯病的防治效果分别为 53.8%和 37.7%。  相似文献   

19.
为了明确关中地区越冬茬番茄黄化曲叶病毒病发生和流行规律,通过分析该病发生与番茄品种、定植期及传播介体烟粉虱之间的关系,并采用PCR技术对田间病原进行分子鉴定。结果表明,番茄黄化曲叶病毒病在8月中下旬至11月上中旬开始侵染,翌年3月中下旬发生再侵染,秋季病情减轻;烟粉虱种群数量与病害发生程度呈线性正相关;不同番茄品种对番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)的抗性差异显著,其中大番茄品种布鲁尼1288和DRW7728,小番茄品种千禧和美红对该病表现为免疫;分子检测结果表明,4个样品中均扩增出543 bp的特异片段,与NCBI数据库Gen Bank的TYLCV序列(登录号为GU084381、KC138544.1、KC138543.1和JX456642.1)的相似性达99%。研究表明,关中地区番茄病毒病为番茄黄化曲叶病毒病,番茄品种、定植期及烟粉虱发生动态是影响该病发生的主要因素。  相似文献   

20.
通过形态特征、生理生化特征和16SrDNA序列分析,对分离于番茄茎部能较强抑制番茄青枯病菌生长的内生细菌B47菌株进行了鉴定。结果表明,该菌为枯草芽孢杆菌,其最适生长pH5~6,最适生长温度为35℃。室内防治试验结果表明,用淋根法先接种B47菌后接种病原菌和用注射法先接种B47菌后接种病原菌的处理可取得81.25%和92.10%的防效,而用淋根法、注射法同时接种B47菌与病原菌的处理防效较低。  相似文献   

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