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Spatial analysis of nuclear and mitochondrial RFLP genotypes in populations of the chestnut blight fungus, Cryphonectria parasitica 总被引:2,自引:0,他引:2
Spatial structure of both nuclear and mitochondrial RFLPs were studied in several populations of the chestnut blight fungus, Cryphonectria parasitica, using a variety of spatial autocorrelation tests designed to detect nonrandom patterns. Fungal individuals were sampled from cankers on infected chestnut trees, and the location of each tree was mapped. Single-locus nuclear RFLPs, nuclear fingerprints, and mitochondrial DNA haplotypes were determined for each individual. Individuals with the same DNA fingerprint genotypes occurred closer together than would be expected at random in four of the five plots, while mitochondrial DNA haplotypes were aggregated in all five plots. Genetic distances between individuals, expressed as one minus the proportion of shared restriction fragment size classes for fingerprints and mitochondrial haplotypes, were significantly correlated with Euclidean distances between individuals in four of the five populations, but these correlations were very weak (r < 0.18). The same DNA fingerprint and single-copy nuclear RFLP alleles occurred on the same trees or immediately neighbouring trees more often than would be expected at random. Most of the aggregation for all three genetic markers occurred among individuals within the same cluster of chestnut stems or on neighbouring trees. Lack of spatial autocorrelation in one population was probably due to sampling on a larger scale that was too coarse to detect any patterns. Significant aggregation of genotypes in C. parasitica is most likely caused by some degree of restricted dispersal within populations. The implications of restricted dispersal are discussed in relation to the breeding system and isolation by distance in populations of. C. parasitica. 相似文献
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生物有机肥对板栗土壤微生物群落代谢活性的影响 总被引:5,自引:0,他引:5
2011年在陕西省柞水县下梁镇沙坪村板栗园,设置对照、施用复合肥和施用生物有机肥3个处理,于板栗收获期采集土壤样品,并运用Biolog方法研究了生物有机肥对土壤微生物群落代谢能力的影响.结果表明:生物有机肥处理的微生物群落碳源利用率(AWCD)、Shannon均匀度、丰富度指数和McIntosh指数均显著高于对照和复合肥处理;与对照相比,施用生物有机肥处理的土壤微生物对糖类和多聚物类碳源的利用能力增强,而施用复合肥处理对各类碳源的利用能力均较弱.主成分分析表明,不同施肥处理的土壤微生物群落明显不同,起分异作用的碳源主要为糖类和氨基酸类. 相似文献
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Ji Won Kim Thi-Kim-Quy Ha Hyomoon Cho Eunhee Kim Sang Hee Shim Jun-Li Yang Won Keun Oh 《Bioorganic & medicinal chemistry letters》2017,27(13):3019-3025
Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea and high fatality of piglets, influencing the swine industry. Japanese horse chestnut (seed of Aesculus turbinata) contains many saponin mixtures, called escins, and has been used for a long time as a traditional medicinal plant. Structure-activity relationship (SAR) studies on escins have revealed that acylations at C-21 and C-22 with angeloyl or tigloyl groups were important for their cytotoxic effects. However, the strong cytotoxicity of escins makes them hard to utilize for other diseases and to develop as nutraceuticals. In this research, we investigated whether escin derivatives 1–7 (including new compounds 2, 3, 5 and 6), without the angeloyl or tigloyl groups and with modified glycosidic linkages by hydrolysis, have PEDV inhibitory effects with less cytotoxicity. Compounds 1–7 had no cytotoxicity at 20 μM on VERO cells, while compounds 8–10 showed strong cytotoxicity at similar concentrations on PEDV. Our results suggest that escin derivatives showed strong inhibitory activities on PEDV replication with lowered cytotoxicity. These studies propose a method to utilize Japanese horse chestnut for treating PEDV and to increase the diversity of its bioactive compounds. 相似文献
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Aspects of the structure and ultrastructure of the fusiform cambial cells of the taproot of Aesculus hippocastanum L. (horse chestnut) are described in relation to the seasonal cycle of cambial activity and dormancy. Particular attention is directed at cell walls and the microtubule and microfilament components of the cytoskeleton, using a range of cytochemical and immunolocalization techniques at the optical and electron-microscopical levels. During the dormant phase, cambial cell walls are thick and multi-layered, the cells possess a helical array of cortical microtubules, and microfilament bundles are oriented axially. In the early stages of reactivation, vesicle-like profiles are associated with the cell walls, whereas arrangement of the cytoskeletal elements remains unchanged. In the succeeding active phase, the cell walls are thin, and cortical microtubules form a random array, although microfilament bundles maintain a near-axial orientation. The observations are discussed in relation to the seasonal cycle of wall structure and cortical microtubule rearrangement within the vascular cambium of hardwood trees. It is suggested that the cell-wall thickening at the onset of cambial dormancy, which is associated with the presence of a helical cortical microtubule array, should be considered to be secondary wall thickening, and that selective lysis of this secondary wall layer during cambial reactivation restores the thinner, primary wall found around active cambial cells. 相似文献
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Five cytokinins, trans-zeatin, 9-β-d-ribosyl-trans-zeatin, O-β-d-glucosyl-trans-zeatin, N6-(3-methyl-but-2-enyl)adenine and N6-(3-methyl-but-2-enyl)adenosine were identified in shoots of the chestnut tree. 相似文献
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Secondary somatic embryos appeared on the cotyledons and radiculi of embryos derived from suspension and anther cultures of Aesculus hippocastanum L. The highest number of secondary somatic embryos formed on a hormone-free medium.This work was supported by the Ministry of Science and Environment Protection of Serbia, grant N0. 1573. 相似文献
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陕西实生板栗居群遗传多样性研究 总被引:11,自引:2,他引:9
利用超薄平板聚丙烯酰胺等电聚焦技术对陕西板栗4个实生居群,8个酶系统的20个位点进行了遗传多样性及遗传结构分析,结果表明:4个居群中以宝鸡居群遗传多样性最高,其P为80.0%,Ho,He分别为0.478和0.343,4个居群的居群遗传分化度Gst为6.2%,平均总遗传多样性为0.3372,总遗传多样性的93.8%属于居群内的遗传变异,聚类分析结果表明,以秦岭为界可以分为秦岭以南与秦岭以北2个略有差异的板栗自然亚分布区。 相似文献
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Sandra L. Anagnostakis 《Biological invasions》2001,3(3):245-254
Climate changes in the past reshaped the North American native forests as some species increased and others decreased in number and distribution. Native American chestnuts were once abundant, but have been eliminated from the forest canopy by two imported pathogens, and are additionally threatened by an imported pest. The trees survive one of the pathogens, but rarely become larger than understory shrubs. These clumps of sprouts provide a reservoir of genetic diversity for use in reinstating this tree into its forest habitat. An imported parasite can be used to control one pathogen and allow the sprouts to grow large enough to flower. The trees can then be crossed with imported chestnuts of other species with good resistance to both pathogens, and resistant offspring selected. Good progress has been made in coping with these imported problems. 相似文献
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转铁蛋白受体单链抗体与BDNF融合蛋白的表达及活性鉴定 总被引:1,自引:0,他引:1
脑源性神经营养因子(BDNF)对中枢神经系统的多种神经元具有营养,修复和保护功能,但因无法通过血脑屏障限制了其应用。本文利用抗转铁蛋白受体(TfR)的单链抗体(ox26-scFv)作为脑转运载体,分别扩增单链抗体和BDNF基因,插入pTIG-Trx载体,构建融合基因表达载体pTIG-Trx/scFv-BDNF,在大肠杆菌BL21(DE3)中实现了高效表达。经Ni-NTA金属鏊合层析柱纯化后,在41Kd处可见目的纯化条带。大鼠GH3细胞免疫酶染色显示,ScFv-BDNF融合蛋白能与转铁蛋白受体特异性结合。同时能够促进鸡胚背根节神经突起的生长,具备了BDNF的生物学活性。为使BDNF能够跨越血脑屏障成为中枢神经系统的治疗药物打下了实验基础。 相似文献
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云龟履硕蚧Perissopneumonxyliae (Ayyar)主要分布于云南玉溪、曲靖、楚雄等地 (州 )的板栗产区 ,是板栗的主要害虫之一。该虫在云南易门每年发生 1代 ,幼虫有 3龄 ,以 3龄若虫在树皮缝隙或树干基部越冬。高温、雨水冲刷、瓢虫捕食、紫胶白虫Eublemmaamabilis捕食和白蜡虫花翅跳小蜂Microterysericeri寄生是其主要的自然控制因子 相似文献
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维生素E对三氯乙烯急性染毒大鼠肝脏脂质过氧化与抗氧化酶的影响 总被引:1,自引:0,他引:1
本文观察了用抗氧化剂维生素E预处理后,三氯乙烯(3000mg/kg B-W-) 一次性经口染毒24h 大鼠肝脏的超氧化物歧化酶、谷胱甘肽过氧化物酶等抗氧化酶活力及丙二醛含量的变化,结果表明三氯乙烯染毒组肝脏中丙二醛含量、超氧化物歧化酶活力及血清谷丙转氨酶、谷草转氨酶活力均高于对照组(P< 0-01) ;而维生素E干预组的丙二醛含量、超氧化物歧化酶活力及血清谷丙转氨酶、谷草转氨酶活力均分别低于三氯乙烯染毒组(P< 0-01) ,说明三氯乙烯急性染毒可引起肝脏脂质过氧化反应及肝损害,肝脏超氧化物歧化酶活力升高可能是机体受自由基及脂质过氧化反应刺激而诱导产生的一种适应性反应,维生素E对三氯乙烯所致的肝损害有一定的保护作用。 相似文献
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蒙古沙鼠脑缺血后大脑皮质Calretinin(CR)的表达变化 总被引:2,自引:2,他引:0
目的:观察蒙古沙鼠前脑短暂缺血后前额皮质Calretinin(CR)的表达变化,为进一步研究其功能及治疗提供形态学依据。方法:24只健康雄性长爪鼠随机分为正常组对照组(6只)和缺血组(18只),夹闭蒙古沙鼠双测颈总动脉10 min诱导前脑缺血后,动物分别存活1天、3天或7天。用免疫组织化学方法检测了前额皮质中CR的表达。结果:与正常组相比,各缺血组中前额皮质中CR表达均上调。缺血再灌1天时,CR表达最强(P<0.01);3天时CR表达开始恢复(P<0.05);7天时CR表达进一步恢复,但仍高于正常组(P<0.01)。结论:前脑短暂缺血后可造成蒙古沙鼠前额皮质CR的表达在短时间内急剧上调;但随着时间的CR的表达会恢复正常。 相似文献
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对RA、HHT和WB_(652)诱导HL-60细胞过程中,细胞浆和膜溶脱部分的蛋白质酪氨酸磷酸化水平变化进行了对比研究,结果发现,在胞浆部分主要有四种含有P-Tyr的蛋白,而且80kD蛋白酪氨酸磷酸化水平随着诱导发生变化。诱导前后内源性蛋白上P-Tyr百分含量也发生了改变。 相似文献
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Diego Gil-Tapetado Fernando Castedo-Dorado María J. Lombardero José Martel Pedro Álvarez-Álvarez 《Journal of Applied Entomology》2021,145(1-2):10-25
Dryocosmus kuriphilus (Hymenoptera: Cynipidae) was first detected in Galicia (NW Spain) in 2014. The wasp then began to spread by stratified dispersal, with the local abundance increasing thereafter. In this study, we analysed location data on wasp-attacked trees, with the following aims: (i) to determine the relative importance of short distance dispersal (SDD) and long-distance dispersal (LDD) on the geographical expansion of the wasp; and (ii) to assess whether the spatial clusters of areas with high and low numbers of attacked trees correspond to areas with different infestation levels and thus whether these areas can be considered suitable proxies for pest abundance. A Random Forest algorithm was used to identify the factors that best discriminate hotspot and coldspot areas. Distance matrix analysis was used considering a conservative expansion rate of the population front of 14 km/year as the threshold for distinguishing SDD and LDD events. Gradients of attacked tree abundance were delineated using the Getis-Ord Gi* statistic. Although LDD events represented a small proportion of the locally dispersing offspring, they determined the rate of spread across the landscape. The infestation level differed significantly between hotspot and coldspot areas, which were therefore used as proxies for D. kuriphilus population abundance. Factors that were favourable or unfavourable in relation to population abundance were mainly associated with maximum temperatures in the summer months. Metrics of composition and configuration of host plant habitat proved less important than the time since invasion and the effect was partly masked by tree diversity at community scale. 相似文献
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The rates of Cl? absorption and HCO?3 secretion were not different in turtle urinary bladders bathed in Na+-containing and solutions.These results in turtle bladder are inconsistent with Na+-anion cotransport but can be accounted for by a Cl?/HCO?3 exchange system. 相似文献
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The distribution of free and protein amino acids during seed development is described for three chestnut varieties. Asparagine accumulation was shown to correlate with protein biosynthesis. Accumulation of free amino acids takes place before that of proteins in ripening seeds. A temporary decrease was generally accompanied by protein biosynthesis and followed by final accumulation of both protein and free amino acids. 相似文献