959 resultados para Peruvian carrot varieties


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田间试验研究不施N和施N(90kg/hm2)条件下“NR9405”、“9430”、“偃师9号”、“小偃6号”、“陕229”、“西农2208”、“矮丰3号”和“商188”等8种不同基因型冬小麦中后期生理特性及其叶片形态的差异结果表明,抽穗期倒二叶和灌浆期旗叶的净光合速率、气孔导度、蒸腾速率及瞬时水分利用效率在不同基因型间存在显著差异,施N仅能显著降低抽穗期倒二叶的蒸腾速率,而对功能叶的其他生理指标无明显影响。小麦成熟期旗叶和倒二叶的长度、宽度及叶面积在不同基因型间也存在极显著差异,施N对这些叶片形态指标有极显著地促进作用,基因型和N肥同时影响灌浆期旗叶的SPAD值,而叶片衰老指数主要受基因型调控。总体上看,冬小麦叶片形态指标同时受施N和基因型影响,而生理指标主要受基因型影响,N肥的影响相对较小。

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In this study, varieties of lipid bilayer-protected gold nanoparticles (AuNPs) were synthesized through a simple wet chemical method, and then the effect of freeze-thawing on the as-prepared AuNPs was investigated. The freeze-thawing process induced fusion or fission of lipid bilayers tethered on the AuNPs. The UV-vis spectra and transmission electron microscopy experiments revealed that the disruption of lipid bilayer structures on the nanoparticles led to the fusion or aggregation of AuNPs.

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The phylogenetic relationships and species identification of pufferfishes of the genus Takifugu were examined by use of randomly amplified polymorphic DNA (RAPD) and sequencing of the amplified partial mitochondrial 16S ribosomal RNA genes. Amplifications with 200 ten-base primers under predetermined optimal reaction conditions yielded 1962 reproducible amplified fragments ranging from 200 to 3000 bp. Genetic distances between 5 species of Takifugu and Lagocephalus spadiceus as the outgroup were calculated from the presence or absence of the amplified fragments. Approximately 572 bp of the 16S ribosonial RNA gene was amplified, using universal primers, and used to determine the genetic distance values. Topological phylogenic trees for the 5 species of Takifugu and outgroup were generated from neighbor-joining analysis based on the data set of RAPD analysis and sequences of mitochondrial 16S rDNA. The genetic distance between Takifugu rubripes and Takifugu pseudommus was almost the same as that between individuals within cacti species, but much smaller than that between T. rubripes, T. pseudommus, and the other species. The molecular data gathered from both analysis of mitochondria and nuclear DNA strongly indicated that T. rubripes and T. pseudommus should be regarded as the same species. A fragment of approximately 900 bp was amplified from the genome of all 26 T. pseudommus individuals examined and 4 individuals of intermediate varieties between T. rubripes and T. pseudommus. Of the 32 T. rubripes individuals, only 3 had the amplified fragment. These results suggest that this fragment may be useful in distinguishing between T. rubripes and T. pseudommus.

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The cold-water subtidal brown alga Laminaria japonica has been commercially fanned in the Far East and has been on top of all marine-fanned species in terms of farming area and annual output worldwide. The successful trials of transplantation of young sporophytes from the north to the south in winter along the Chinese coast in the 1950s led to the spreading of cultivation activities down to a latitude of 25-26 degrees N. Up to today, nearly 50% of the annual output of this farmed alga, as a cold-water species, comes from the sub-tropical south in China. The demand to have high-temperature-tolerant strains/ecotypes in farming area calls for a practical method to judge and select the desired parental plants for breeding programs and for seedling production. In this paper, we report our results on using chlorophyll fluorescence measurement and short-term growth performance in tank culture to estimate the temperature tolerance of offspring from two populations, Fujian Farmed Population (FFP) sampled from Fujian province (latitude: 25-26 degrees N) in subtropical area and Qingdao Wild Population (QWP) sampled from Qingdao (latitude: 36 degrees N). Contrary to what has been usually thought, the results revealed that offspring from Qingdao wild population in the north showed better performance both in short-term growth and survival rates and in optimal quantum efficiency (F-v/F-m) when exposed to higher temperature (20-25 degrees C). This result was further confirmed by fluorescence quenching analysis. QWP distributed along the southern distribution limit at a latitude of 36 degrees N in the Pacific west coast is thus taken as a more ideal one than the fanned population in subtropical region as a source of parental plants for breeding high-temperature-tolerant varieties. (c) 2006 Elsevier B.V. All rights reserved.

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A2 x 2 factorial cross between two populations of Pacific abalone Haliotis discus hannai Ino, collected separately from Dalian (D) in China and Miyagi (M) in Japan, was conducted to compare performances in fertilization rate, hatching rate, metamorphosis rate and growth at days 20, 43, 160 and 330 between purebreds (DD and MM) and crossbreds (DM and MD) and investigate the magnitude of heterobeltiosis (better parent) and heterosis (mid-parent). Heterobeltiosis and heterosis for all the traits analyzed were evidently different between crossbreds DM and MD. Heterobeltiosis in the crossbred DM varied among traits, with values of 2.5% for the fertilization rate, 2.2% for the hatching rate, -1.9% for the metamorphosis rate and 7.4% for the growth at the (lay 330. The crossbred DM displayed positive heterotic values for fertilization rate (5.4%), hatching rate (7.4%), metamorphosis rate (7.6%) and growth (12.0%) at the day 330. However, both heterobeltiosis and heterosis for all the traits in the crossbred MD were negative except those for the growth at days 20 and 43. The results indicate the importance of selecting superior hybrid varieties if the exploitation of hybrid vigor is considered in the Pacific abalone breeding program.

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The paper systematically discusses the mechanism for glycinebetaine to improve plant salt resistance and its research advances in genetic engineering at home and abroad as well as summarizing the research progresses about the key enzymes and their genetic engineering in glycinebetaine biosynthesis. It suggests that on the basis of further understanding the mechanism for glycinebetaine to improve plant salt resistance,the transformation of the genes relating to glycinebetaine biosynthesis should be carried out in major crops so that new plant varieties resistant to salt can be obtained.

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Repeated cycles of retreat and recolonization during the Quaternary ice ages are thought to have greatly influenced current species distributions and their genetic diversity. It remains unclear how this climatic oscillation has affected the distribution of genetic diversity between populations of wind-pollinated conifers in the Qinghai-Tibetan region. In this study, we investigated the within-species genetic diversity and phylogenetic relationships of Picea likiangensis, a dominant forest species in this region using polymorphic DNA (RAPD) markers. Our results suggest that this species has high overall genetic diversity, with 85.42% of loci being polymorphic and an average expected heterozygosity (H (E)) of 0.239. However, there were relatively low levels of polymorphism at population levels and the differences between populations were not significant, with percentages of polymorphic bands (PPB) ranging from 46.88 to 69.76%, Nei's gene diversity (H (E)) from 0.179 to 0.289 and Shannon's indices (Hpop) from 0.267 to 0.421. In accordance with our proposed hypothesis, a high level of genetic differentiation among populations was detected based on Nei's genetic diversity (G (ST) = 0.256) and AMOVA analysis (Phi (st) = 0.236). Gene flow between populations was found to be limited (Nm = 1.4532) and far lower than reported for other conifer species with wide distribution ranges from other regions. No clusters corresponding to three morphological varieties found in the south, north and west, respectively, were detected in either UPGMA or PCO analyses. Our results suggest that this species may have had different refugia during the glacial stages in the southern region and that the northern variety may have multiple origins from these different refugia.

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Application of long-term exploration for oil and gas shows that the reservoir technology of prediction is one of the most valuable methods. Quantitative analysis of reservoir complexity is also a key technology of reservoir prediction. The current reservoir technologies of prediction are based on the linear assumption of various physical relationships. Therefore, these technologies cannot handle complex reservoirs with thin sands, high heterogeneities in lithological composition and strong varieties in petrophysical properties. Based on the above-mentioned complex reservoir, this paper conducts a series of researches. Both the comprehending and the quantitative analysis of reservoir heterogeneities have been implemented using statistical and non-linear theories of geophysics. At the beginning, the research of random media theories about reservoir heterogeneities was researched in this thesis. One-dimensional (1-D) and two-dimensional (2-D) random medium models were constructed. The autocorrelation lengths of random medium described the mean scale of heterogeneous anomaly in horizontal and deep directions, respectively. The characteristic of random medium models were analyzed. We also studied the corresponding relationship between the reservoir heterogeneities and autocorrelation lengths. Because heterogeneity of reservoir has fractal nature, we described heterogeneity of reservoir by fractal theory based on analyzing of the one-dimensional (1-D) and two-dimensional (2-D) random medium models. We simulated two-dimensional (2-D) random fluctuation medium in different parameters. From the simulated results, we can know that the main features of the two-dimensional (2-D) random medium mode. With autocorrelation lengths becoming larger, scales of heterogeneous geologic bodies in models became bigger. In addition, with the autocorrelation lengths becoming very larger, the layer characteristic of the models is very obvious. It would be difficult to identify sandstone such as gritstone, clay, dense sandstone and gas sandstone and so on in the reservoir with traditional impedance inversion. According to the obvious difference between different lithologic and petrophysical impedance, we studied multi-scale reservoir heterogeneities and developed new technologies. The distribution features of reservoir lithological and petrophysical heterogeneities along vertical and transverse directions were described quantitatively using multi-scale power spectrum and heterogeneity spectrum methods in this paper. Power spectrum (P spectrum) describes the manner of the vertical distribution of reservoir lithologic and petrophysical parameters and the large-scale and small-scale heterogeneities along vertical direction. Heterogeneity spectrum (H spectrum) describes the structure of the reservoir lithologic and petrophysical parameters mainly, that is to say, proportional composition of each lithological and petrophysical heterogeneities are calculated in this formation. The method is more reasonable to describe the degree of transverse multi-scale heterogeneities in reservoir lithological and petrophysical parameters. Using information of sonic logs in Sulige oil field, two spectral methods have been applied to the oil field, and good analytic results have been obtained. In order to contrast the former researches, the last part is the multi-scale character analysis of reservoir based on the transmission character of wave using the wavelet transform. We discussed the method applied to demarcate sequence stratigraphy and also analyzed the reservoir interlayer heterogeneity.

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Jiaodong Peninsula is the largest repository of gold in China. Varieties of studies have been involved in the mechanism of metallogenesis. This thesis is a part of the project "Study of basic geology related to the prespecting of the supra-large deposits" which supported by National Climbing Program of China to Prof. Zhou. One of the key scientific problems is to study the age and metallogenic dynamics of ore deposit and to understand how interaction between mantle and crust constrains on metallogenesis and lithogenesis. As Jiaodong Peninsula to be study area, the Rb-Sr, Sm-Nd and Pb isotopic systematics of pyrite and altered rocks are measured to define the age and origin of gold. The elemental and Sr-Nd-Pb isotopic compositions of dikes and granites was studied to implicate the source and lithogenesis of the dike and granite and removal of lithosphere and the interaction between mantle and crust in the Jiaodong Peninsula. Considering the tectonic of Jiaodong Peninsula, basic on the time and space, this thesis gives a metallogenic dynamics of gold mineralization and discusses the constraints of the interaction between mantle and crust on the metallogenesis and lithogenesis. This thesis reports the first direct Rb-Sr dating of pyrites and ores using sub-sampling from lode gold deposit in Linglong, Jiaodong Peninsula and the results demonstrate this as a useful geochronological technique for gold mineralization with poor age constraint. The Rb-Sr data of pyrites yields an isochron age of (121.6-122.7) Ma, whereas, those of ore and ore-pyrite spread in two ranges from 120.0 to 121.8 Ma and 110.0-111.7 Ma. Studies of characteristic of gold deposit, microscopy of pyrite and quartz indicate that the apparent ages of ore and ore-pyrite are not isochron ages, it was only mixed by two end members, i.e., the primitive hydrothermal fluids and wall rocks. However, the isochron age of pyrite samples constrains the age of gold mineralization, i.e., early Cretaceous, which is in good consistence with the published U-Pb ages of zircon by using the SHRIMP technique. The whole rock Rb-Sr isochron age of altered rocks indicates that the age of gold mineralizing in the Xincheng gold deposit is 116.6 ± 5.3 Ma. The Sr, Nd and Pb isotopic compositions of pyrite and altered rocks indicate that the gold and relevant elements were derived from multi-sources, i.e. dikes derived from enriched lithospheric mantle and granites, granodiorites and metamorphic rocks outcropped on the crust. It also shows that the hydrothermal fluids derived from mantle magma degassing had play an important role in the gold mineralizing. The major and trace elements, Sr-Nd-Pb isotopic data of granites and granodiorites suggest that the Linglong Granite and Kunyushan Granite were derived from partial melting of basement rocks in the Jiaodong Peninsula at post-collision of North China Craton with South China Craton. Guojialing Granodiorite was considered to be derived from a mixture source, that is, mixed by magmas derived from an enriched lithospheric mantle and crust during the delamination of lithosphere induced by the subduction of Izanagi Plate and the movement of Tancheng-Lujiang Fault. There are kinds of dikes occurred in the Jiaodong Peninsula, which are accompanying with gold mineralization in time and space. The dikes include gabrro, diabase, pyroxene diorite, gabrrophyre, granite-porphyry, and aplite. The whole rock K-Ar ages give two age intervals: 120-124 Ma for the dikes that erupted at the gold mineralizing stage, and <120 Ma of the dikes that intruded after gold mineralizing. According to the age and the relationship between the dikes and gold mineralizing, the dikes could be divided into two groups: Group I (t = 120-124 Ma) and Group II (t < 120Ma). Group I dikes show the high Mg and K, low Ti contents, negative Nb anomalies and positive Eu anomalies, high ~(87)Sr/~(86)Sr and negative εNd(t) values and an enrichment in light rare earth elements, large ion lithosphile elements and a depletion in high field strength elements. Thus the elemental and isotopic characteristics of the Group I dikes indicate that they were derived from an enriched lithospheric mantle perhaps formed by metasomatism of the melt derived from the recycled crustal materials during the deep subduction of continent. In contrast, the Group II dikes have high Ti, Mg and K contents, no negative Nb anomalies, high ~(87)Sr/~(86)Sr and positive or little negative εNd(t) values, which indicate the derivation from a source like OIB-source. The geochemical features also give the tectonic constraints of dikes, which show that Group I dikes were formed at continental arc setting, whereas Group II dikes were formed within plate background. Considering the tectonic setting of Jiaodong Peninsula during the period of gold mineralizing, the metallogenic dynamics was related to the subduction of Izanagi Plate, movement of Tancheng-Lujiang Fault and removal of lithopheric mantle during Late Mesozoic Era.

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Previous studies have witnessed some psychological or behavioral deviation (such as aggressive behavior) might have an association with cerebral hemisphere cooperative dysfunction, however, it is still unclear whether there is an association between individuals with social cognitive bias and their hemispheric cooperative functions especially while the interhemisphere cooperative processing is under the conditions of emotional interferences. The purpose of this study is to explore the differences between the social cognitive bias group and the normal group’s interhemispheric cooperative functional activity under the conditions of with or without interferences. Methods: According to Dodge’s (1993) model of “social-cognitive mechanisms in the development of conduct disorder and depression”, a 51 items of “social cognitive bias scale” was created and was used to screen the high score group. 20 male subjects was composed of high score group and other 23 matched the control group. Stimulus tachistoscopically presented to the bilateral visual field and compared with the central. Both group’s interhemispheric cooperative functional activity were observed and compared under the conditions of without interference- i.e. base level and with the emotional interferences of white noise level and negative evaluative feedback speech level while finishing: experiment one: Chinese word-figure Stroop analogue task; experiment two: two single Chinese Characters combination task. Heart rate and respiratory rate were simultaneously recorded as index of emotional changes. Results: ① The high score group showed a decrease in processing accuracy compared with the normal group under the condition of white noise interference level in experiment one. ② Still under the condition of white noise interference level, there were more reaction time and more errors were observed in high score group than normal in experiment two. ③ Both groups showed speed up effect and the strategic processing tendency of speed-accuracy trade-off effect under the condition of white noise interference level in both experiments. ④ Between group differences of interhemipheric cooperative function were not observed under the conditions of base level and the negative evaluative feedback speech level within both experiments. Conclusion: The results suggested that interhemispheric cooperative functional differences exists between the two groups, characterized as ① differences existed in interhemispheric cooperative processing strategy between the two groups, with the high score group presented “hierarchic” deficiency strategy. ② the appearance of the differences between the two groups were condition specified , and in this research it was only under the white noise interference condition. ③ the features of the differences between the two groups were the differences on multidimensional performances and with a deficit orientation in high score group. ④ the varieties of the differences were changing with cooperative tasks, as in this research the high score group performed worse in complementary cooperative task. In addition, both group adjusted the processing strategy respectively under the condition of white noise evoked emotional interference implied that the interaction between the interhemisphere cooperative processing and emotion might exist.

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The purpose of this study was to explore the development of the cognitive processing on temporal continuity (duration) in primary school children with the information processing approach. The results showed: (1) The performances of cognitive processing on compound duration developed increasingly with age. (2) The intervals of duration, the method of display, the varieties of display had effects on cognitive processing of compound duration; however, the effective ways and extents varied with the specific tasks. (3) The primary school children could use cognitive strategies initially, the effectiveness and the flexibility of strategies developed increasingly with age.

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1999

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Etiologia; Sintomatologia; Variabilidade de espécies dos nematóides; Produção de inóculo; Metodologia de avaliação da resistência; Fator de reprodução dos nematóides (FR); Percentagem de infecção de raízes comerciais; Avaliação da resistência das progênies na Embrapa Hortaliças.

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1998