Detection and identification of the phytoplasma associated with pear decline in Taiwan     

Hsiu-Lin Liu  Ching-Chung Chen  Chan-Pin Lin 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(3):281-291

Pear decline (PD) is an important phytoplasmal disease that occurs mainly in Europe and North America. In 1994, pear trees exhibiting symptoms typical of PD disease were observed in orchards of central Taiwan. The sequence of 16S rDNA and 16S–23S rDNA intergenic spacer region (ISR) of the causative agent of pear decline in Taiwan (PDTW) were amplified with polymerase chain reaction (PCR) using a DNA template prepared from the diseased leaves. Sequence analysis of 16S rDNA revealed that the PDTW agent was closely related to the phytoplasmas of the apple proliferation group that cause diseases in stone fruits, pear and apple. Consistent with the result of 16S rDNA sequence analysis, sequence analysis of the 16S–23S rDNA ISR and putative restriction site analyses of 16S rDNA and 16S–23S rDNA ISR sequences provided further support for the view that the PDTW phytoplasma causing pear decline in Taiwan may represent a new subgroup of the apple proliferation group. According to the rDNA sequence of PDTW phytoplasma, two specific PCR primer pairs, APf2/L1n and fPD1/rPDS1, were designed in this study for the detection of the etiological agent in pear trees and insect vectors. Based on the sequence analyses of the PCR-amplified fragments, two species of pear psyllas, Cacopsylla qianli and Cacopsylla chinensis, were found to carry PDTW phytoplasma.  相似文献   

‘Candidatus Phytoplasma australiense’ is the phytoplasma associated with Australian grapevine yellows, papaya dieback and Phormium yellow leaf diseases     

Lia W. Liefting  Anna C. Padovan  Karen S. Gibb  Ross E. Beever  Mark T. Andersen  Richard D. Newcomb  David L. Beck  Richard L.S. Forster 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(6):619-623

Sequence comparisons and phylogenetic analysis of the 16S rRNA genes and the 16S/23S spacer regions of the phytoplasmas associated with Australian grapevine yellows, papaya dieback and Phormium yellow leaf diseases revealed minimal nucleotide differences between them resulting in the formation of a monophyletic group. Therefore, along with Australian grapevine yellows, the phytoplasmas associated with Phormium yellow leaf and papaya dieback should also be considered as Candidatus Phytoplasma australiense.  相似文献   

草鱼MYH mRNA表达量分析中采用的内参基因稳定性比较     

周瑞雪  ;蒙涛  ;赵发兰  ;成嘉  ;宾石玉  ;张建社  ;褚武英 《广西农业生物科学》2009,(5):896-900

本研究分别以β-actin、18SrRNA和GAPDH为内参基因,采用实时荧光定量PCR对草鱼早期发育时期肌球蛋白重链（myosin heavy light,MYH）基因的mRNA表达量进行分析,并比较不同内参基因对MYH基因mRNA表达水平检测结果的准确性。研究结果表明,以β-actin和GAPDH作为内参,MYH基因mRNA表达水平完全一致,其表达量从原肠到仔鱼阶段逐次递增,仔鱼与原肠期阶段相比表达量差异显著;当采用18S rRNA作为内参时,MYH基因mRNA在发育阶段的表达量呈不稳定状态。因此,β-actin和GAPDH均可作为内参基因,用于草鱼早期发育中MYH基因mRNA的相对定量研究;而18S rRNA作为内参时,可能会对检测结果造成偏差。本研究不仅准确的揭示了草鱼MYH基因mRNA的表达特征,并且为荧光定量PCR技术在鱼类基因表达研究方面提供了有价值的参考。  相似文献   

Genotypic and phenotypic characterization of lactic acid bacteria isolated from Italian ryegrass silage     

Masanori TOHNO  Hisami KOBAYASHI  Masaru NOMURA  Maki KITAHARA  Moriya OHKUMA  Ryuichi UEGAKI  Yimin CAI 《Animal Science Journal》2012,83(2):111-120

Twenty-three lactic acid bacteria (LAB) isolated from three cultivars (Akiaoba, Nagahahikari and Tachiwase) of Italian ryegrass (Lolium multiflorum Lam.) silage were precisely characterized by a combination of phenotypic tests, genotypic 16S ribosomal DNA sequencing and rapid PCR-based analyses, focusing on their useful phenotypes for silage preparation as inoculants. We successfully identified both at the species and subspecies levels: phenotypically novel Lactococcus lactis subsp. lactis, Lactobacillus brevis, Lactobacillus coryniformis subsp. torquens, Lactobacillus curvatus, Lactobacillus plantarum subsp. plantarum, Lactobacillus sakei subsp. carnosus, Leuconostoc mesenteroides subsp. dextranicum and Pediococcus parvulus. This is the first report to elucidate the presence of Lactobacillus coryniformis ssp. torquens and Leuconostoc mesenteroides subsp. dextranicum in Italian ryegrass silages. Physiological and biochemical tests revealed that phenotypic characteristics are different among the different strains of the same species and subspecies, and that the isolates show unique and diverse phenotypes related to fermentation factors, such as available carbohydrates, optimal growth pH and temperature. These results suggest that, for various well-preserved silage preparations, the isolates may be useful in producing novel inoculants corresponding to their optimally climatic and ecological niches.  相似文献   

北方早粳型光温敏不育系108S的选育与利用     

《杂交水稻》2000,(Z1)

光温敏不育系 10 8S是北方杂交粳稻工程技术中心用N42 2S与C90 2 2杂交 ,经系谱选择法选育出的光温互作型早粳型不育系。它具有起点温度低、米质优、制繁种产量高、配合力强、适应性广等优点。它的育成 ,对北方两系法的应用具有重大影响  相似文献   

Serum concentration of S100-B protein in patients during CABG with or without cardiopulmonary bypass     

HONG Feng  PENG Jian-ming  ZHANG Rui-xiang  CHEN Jun-peng 《园艺学报》2007,23(7):1293-1295

AIM: To investigate the mutative law of the serum S100-B protein in patients undergone coronary artery bypass grafting with or without cardiopulmonary bypass (CPB-CABG or non-CPB CABG), and to compare the degree of cerebral injury in patients during CABG between the two different surgical manipulations.METHODS: 30 patients were divided into two groups: CPB-CABG group (group A) and non-CPB CABG group (group B). Every group included 15 patients. Blood from jugular vein was phlebotomized in every patients at the following 8 time points: before operation (OP), after anaesthesia, end of grafting, end of OP, 2 h after OP, 6 h after OP, 12 h after OP and 24 h after OP. The serum concentrations of S100-B protein in the samples were measured.RESULTS: The level of serum S100-B protein increased markedly at the beginning of CABG, and the peak value of group A (2.32 μg/L±0.26 μg/L) was treble higher than that in the patients in group B (0.71 μg/L±0.14 μg/L). The levels of S100-B protein tend to normal level in both groups 24 h after OP. The level of S100-B protein had notable relation with the time of CABG in group A and the manipulative time on the heart in group B.CONCLUSION: The degree of cerebral damage can be valued by investigating the mutative law of the serum S100-B protein in patients undergone CPB-CABG and non-CPB CABG. The non-CPB CABG reduces the degree of cerebral damage and avoids the functional disorder of central nerve.  相似文献   

Analysis of 18S rRNA gene of Octostigma sinensis (Projapygoidea: Octostigmatidae) supports the monophyly of Diplura     

Yun-Xia Luan  Yong-Gang Yao  Rong-Dong Xie  Yi-Ming Yang  Ya-Ping Zhang  Wen-Ying Yin   《Pedobiologia》2004,48(5-6):453-459

The phylogenetic position of Diplura within Hexapoda has been controversial. There are three major lineages in Diplura: Campodeoidea, Projapygoidea, and Japygoidea. However, most of the previous studies were restricted to Campodeoidea and Japygoidea. Until now, only preliminary morphological study on Projapygoidea was reported, and no sequence data from Projapygoidea was available. The main aim of the present study was to investigate the phylogenetic position of Octostigmatidae, one of the three families of Projapygoidea, in Diplura and to test if Diplura are monophyletic. The complete 18S rRNA gene sequences of Octostigma sinensis (Projapygoidea: Octostigmatidae) from subtropical China, together with representative species of Campodeoidea and Japygoidea, and several species of Protura and Collembola were analyzed. The phylogenetic trees were obtained by different methods (neighbor-joining, maximum parsimony, and maximum likelihood) with a chelicerate species as outgroup. Our results suggested that Octostigma was closer to the genus Parajapyx (Japygoidea: Parajapygidae) than to the representative genus of Campodeidae (Campodeoidea). All phylogenetic trees supported the monophyly of Diplura.  相似文献   

Immunopathology of the eye: Purification of canine retinal “S” antigen     

C. Secchi  L. Oldani  C. Peruccio  M. Guttinger  A. Berrini  C. Caldora  G. Poli 《Comparative immunology, microbiology and infectious diseases》1985,8(3-4):297-303

Canine retinal S antigen has been purified to study the retinal progressive atrophy of the dog. The purified antigen will be used to detect, by the ELISA technique, specific autoantibody in dogs with ocular diseases.  相似文献   

The Nutritive Value and Yield of Alfalfa Cultivated on Sulphur Postmining Lands     

T. R. Pucek  J. B. Py&#; 《Journal of Agronomy and Crop Science》1999,182(3):185-192

The study was carried out on the reclaimed lands of a bore-hole sulphur mine. The cropping of two succeeding cuts of alfalfa (Medicago sativa L.) was determined and its chemical composition was analyzed. Alfalfa was cultivated on waste lime (flotation tailings), enriched with a humus layer. The levels of basic nutrients, total S, total F, Ca, P, Mg, K, Na, Fe and Mn were determined in alfalfa. The biomass of an average crop was 6830 kg  ha^–1 in the first cut and 14300 kg  ha^–1 in the second one. The yields of dry matter as well as of crude and true proteins were positively correlated with the phosphorus level in the dry matter of alfalfa (P < 0.01). The level of total sulphur was positively linearly correlated with the phosphorus content (P < 0.01). No harmful accumulation of sulphur or fluoride was observed. A deficiency of phosphorus in alfalfa and an abnormal Ca:P weight ratio was found. The S total level was positively correlated with N total concentration. (P < 0.01). The percentage of true protein in crude protein was negatively correlated with total sulphur (P < 0.01). The level of nonprotein nitrogen compounds was positively correlated with S total level (P < 0.01).  相似文献   

培矮64S系列组合制种稻粒黑粉病防控技术研究     

唐建初  邢芳超 《杂交水稻》1998,13(3):14-16

研究了肥水管理、“九二０”施用时期与用量、轻度割叶对两系杂交水稻培矮６４Ｓ系列组合制种稻粒黑粉病发生的影响，提出降低氮肥用量、及早晒田控制无效分蘖，在见穗蔸率３％～５％喷施“九二０”，适当增加其用量以及在喷完后轻度割叶等措施，能有效降低稻粒黑粉病的发生率。  相似文献