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21.
Rapid detection of Phytophthora cinnamomi using PCR with primers derived from the Lpv putative storage protein genes 总被引:1,自引:1,他引:1
Phytophthora cinnamomi is an ecologically and economically important pathogen. In this study, PCR assays were developed with primer pair LPV2 or LPV3 for rapid detection and identification of this organism. Both primer pairs were selected from putative storage protein genes. The specificity of these primer pairs was evaluated against 49 isolates of P. cinnamomi , 102 isolates from 30 other Phytophthora spp., 17 isolates from nine Pythium spp. and 43 isolates of other water moulds, bacteria and true fungi. PCR with both primer pairs amplified the DNA from all isolates of P. cinnamomi regardless of origin. The LPV3 primers showed adequate specificity among all other species tested. The LPV2 primers cross-reacted with some species of Pythium and true fungi, but not with any other Phytophthora species. PCR with the LPV3 primers detected the pathogen at levels of a single chlamydospore or 10 zoospores in repeated tests. The PCR assay was at least 10 times more sensitive than the plating method for detection of the pathogen from artificially infested soilless medium, and, to a lesser extent, from naturally infected plants. PCR with LPV3 primers can be a useful tool for detecting P. cinnamomi from soilless media and plant tissues at ornamental nurseries, whereas the LPV2 primers can be an effective alternative for identification of this species from pure culture. Applications of these assays for detection of P. cinnamomi in other environments were also discussed. 相似文献
22.
棉铃虫核型多角体病毒分子生物学和基因工程研究进展 总被引:1,自引:1,他引:1
棉铃虫核型多角体病毒(HaSNPV)是棉铃虫专一性病原物,隶属于杆状病毒科核型多角体病毒属.对其分子生物学和基因工程的研究主要包括以下几个方面:测定了HaSNPV G4株和C1株基因组核苷酸全序列,并与其它病毒进行了同源性比较;研究了HaSNPV部分基因的结构、转录、表达及其功能.构建了HaSNPV Bac to Bac杆状病毒表达系统;重组病毒杀虫剂的研究为HaSNPV大面积防治棉铃虫展示了广阔的前景.随着棉铃虫核型多角体病毒分子生物学和基因工程研究的不断深入,重组病毒杀虫剂将在棉铃虫综合防治中发挥更为重要的作用. 相似文献
23.
苹果基因组分子生物学研究进展 总被引:4,自引:1,他引:4
借助分子标记手段苹果基因组研究取得了巨大成就,涉及苹果的抗性、生长发育、果实品质等各方面基因,综合有关文献,将其研究的主要成果,包括已发现的主要苹果遗传标记、已构建的苹果遗传连锁图谱及苹果的转基因研究进行综述,并对目前苹果基因组研究存在的问题和对策进行了分析,以期为苹果遗传育种提供参考。 相似文献
24.
Mariner转座子与小菜蛾抗性关系的研究 总被引:1,自引:1,他引:1
以抗溴氰菊酯、杀虫双、杀螟丹小菜蛾种群及其敏感品系为研究对象,借助聚合酶链式反应(PCR)、载体筛选、琼脂糖凝胶电泳等实验技术,检测了小菜蛾4个品系的Mariner转座子的存在及其与抗性的关系。结果表明,在抗溴氰菊酯、杀虫双、杀螟丹以及敏感品系的小菜蛾中都存在两种大约500 bp的Mariner转座子片断,初次证明在小菜蛾4个品系中均含有两种Mariner转座子,并发现一种新的转座子基因片断,但是没有发现Mariner转座子与抗性之间存在直接的联系。研究结果将为利用Mariner转座子标签法在小菜蛾中分离定位基因、转化外源基因、转基因昆虫防治害虫等研究提供理论基础。 相似文献
25.
K. A. Selting S. E. Lana G. K. Ogilvie A. Olmstead D. L. Mykles J. Bright K. L. Richardson J. A. Walton E. Monnet M. J. Fettman 《Veterinary and comparative oncology》2004,2(3):142-156
The cumulative cardiotoxicity that occurs as a result of doxorubicin chemotherapy is irreversible and can affect both quality and quantity of life for the cancer patient. Cardiac troponin I (cTnI) is a sensitive and specific marker of cardiomyocyte death. The purpose of this retrospective study was to evaluate serum concentrations of cTnI in dogs with lymphoma or osteosarcoma given doxorubicin chemotherapy, and with known cardiac outcome, based on a minimum assessment by physical examination and thoracic radiography. Serum samples were also available for cTnI measurement from seven healthy dogs given intracoronary doxorubicin. Serial serum samples obtained before, during and after doxorubicin chemotherapy showed increased cTnI concentrations in some clinical patients following chemotherapy (P = 0.0083 compared to baseline), but this did not correlate with clinical signs of cardiomyopathy. In dogs that subsequently developed cardiomyopathy however, serum cTnI concentrations were elevated before clinical signs became evident (confirmed with echocardiography). 相似文献
26.
Thomas Miedaner Angela G. Schilling Geiger 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(1):63-70
Fusarium culmorum is a phytopathogenic, toxigenic fungus causing seedling diseases, foot rot and head blight of cereals. For estimating competition effects in mixtures of two single-spore isolates, two winter rye single crosses were tested with either four isolates individually or four 1 : 1 mixtures of the same isolates in six field environments. Two isolates (FC46, FC64) were highly aggressive deoxynivalenol (DON) and 3-acetyl DON-producers, the other two (FC30, FC71) were medium aggressive nivalenol-producers. Rye heads were inoculated during flowering with conidia of pairs of isolates expressing similar (FC46 + FC64, FC30 + FC71) or contrary (FC46 + FC71, FC30 + FC64) levels of aggressiveness and similar or different concentrations and chemotypes of mycotoxins, respectively. Head blight rating and yield components relative to the non-inoculated plots were recorded as aggressiveness traits. Additionally, mycotoxin concentrations were measured in the rye grain. Random pathogen samples were re-isolated from heads at the onset of symptom development and analysed by molecular markers (RAPD–PCR) in one environment. Aggressiveness of the isolate mixtures was significantly lower than that of the isolates applied individually on both rye genotypes. Similarly, mycotoxin concentrations were significantly lower in the mixtures in seven out of eleven comparisons. Among the re-isolates, the component genotypes of a mixture significantly deviated from the inoculated 1 : 1 ratio when a particular isolate (FC46) was present in the mixture. This isolate displayed a superior competitive ability irrespective of the aggressiveness or mycotoxin profile of the mixing partner illustrating that pathogenic fitness is caused by additional factors that have not, as yet, been identified. 相似文献
27.
28.
A. V. Vasileva E. V. Gorbunova A. S. Vasilev V. S. Peretyagin A. N. Chertov V. V. Korotaev 《British poultry science》2018,59(6):636-645
ABSTRACT1. The objective of this study was to develop a machine vision method for analysing exterior parameters of chicken eggs to automate the stage of primary sorting.2. The developed algorithm based on predetermined thresholds calculated egg quality indicators, including geometric dimensions, shape index and the mottling grade. The algorithm was implemented with an experimental setup that combined the image-based and the candling methods. A total of 400 egg samples were analysed.3. Comparison of results of the algorithm with those obtained using the traditional manual method showed that mean value of radii values difference was 0.095 ± 0.058 mm for the sharp and 0.080 ± 0.047 mm for the blunt end of the egg, with standard deviations of 0.58 mm and 0.49 mm, respectively.4. The correlation coefficient between the shape index values determined by the two methods was 0.93; the standard deviation of absolute differences between corresponding values was 1.05%.5. The results of mottling grade estimation were compared using F-measure and confusion matrix.6. The results allow the possibility to perform the assessment of egg exterior quality factors in an automatic mode, independent of the expertise of a grader. 相似文献
29.
ABSTRACT1. The objectives of the current study were to investigate the mitochondrial genome and molecular phylogeny of Lueyang black-bone chicken, and provide molecule base to preserve and explore the specific chicken strain.2. Based on sequencing and clustering, the complete mitochondrial DNA map and sequences of Lueyang black-bone chicken were revealed, and two phylogenetic trees of Lueyang black-bone chickens based on D-loop sequences and the mitochondrial genome were constructed.3. The results showed that the complete mitochondrial genome of Lueyang black-bone chickens is 16,784bp in size, consisting of 22 transfer RNA genes, two ribosomal RNA genes, 13 protein-coding genes, and one non-coding control region. The base composition of the complete mtDNA sequence is 30.28% for A, 23.78% for T, 32.42% for C, 13.52% for G. Additionally, 10 haplotypes of D-loop sequences in 32 Lueyang black-bone chickens were detected, which were distributed into 4 clades (A, B, C and E).4. It was concluded that genetic diversity is wide in Lueyang black-bone chickens, and this strain has multiple maternal origins from different regions in China and neighbouring regions. 相似文献