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51.
Base on the Kevin Lynch's city image theory, from the path, edge, district, node, landmark five cognitive maps to analyses the space structure and characteristics of Xing Cheng city. And Base on these analyses to discuss how to control the spatial morphology of Xing Cheng city, which provides a theoretical reference and reference examples for the protection and control of ancient city spatial morphology in the future. 相似文献
52.
《Plant Production Science》2013,16(1):76-81
SummaryWheat (Triticum aestivum L. cv. Norin 61) plants were grown under five different photon flux densities obtained by modulating the number of green light-emitting diodes (LEDs) under white fluorescent lamps. The experiment was conducted under continuous irradiation at a constant temperature of 20°C to clarify the developmental responses of wheat to the fluence rate of green light. The higher the photon flux density of green light, the shorter the number of days from emergence to heading. The earliest heading was observed in the plants grown under 496 green LEDs, 32.0 days after emergence. A significant logarithmic function could fit the relationship between the fluence rate of green light and developmental rate. In this report, principal component analysis (PCA) was adopted to analyze the confounding of green light versus photosynthetic photon flux density (PPFD) with 17 developmental and morphological traits. The eigenvalues explained were 5.64, 3.20, and 2.61, respectively, for the first, second and third principal components (PCs). The first PC was assumed as the factor related to the isometric growth, and the third PC was assumed as the factor related to the developmental rate and culm elongation. Therefore, it was supposed that the first and third PCs were affected by the PPFD and the photon flux density of green light, respectively. The results suggested that the fluence rate of green light affects the development of wheat as a signal source. Furthermore, the development of wheat was promoted by the green light independent of PPFD. 相似文献
53.
54.
《Plant Production Science》2013,16(1):13-19
AbstractMorphological changes and function of calcium oxalate crystals in eddo roots in hydroponic solution containing calcium at various concentrations were investigated. Bundles of needle-shaped crystals in crystal idioblasts were tubularly arranged in the peripheral part of cortex in the apical zone of primary roots. Under scanning electron microscopy and optical microscopy, crystals in the idioblasts of roots cultured in 1 mM calcium nitrate solution were larger than those in 0 mM calcium solution but smaller than those in the solutions containing either 15 mM calcium nitrate or 15 mM calcium chloride. The number and area of crystal bundles in the sections of the apical zone in 1 mM calcium nitrate solution were significantly larger than those in 0 mM calcium solution and smaller than those in the solutions containing 15 mM calcium. The calcium mapping image obtained by energy dispersive X-ray spectrometry showed that the amount of calcium in crystal idioblasts was increased with increasing calcium concentration in the solutions. However, the weight percentage of calcium per cortex parenchyma cell in root apical zone did not vary significantly with the concentration of calcium in the solutions. In the root zone apart from the root apex having no crystals, the weight percentage of calcium per cortex parenchyma cell in the solutions containing 15 mM calcium was significantly higher than that in either 0 mM calcium or 1 mM calcium nitrate solution. These results suggested that the crystals in the tubular arrangement participated in the regulation of calcium levels in the apical zone of primary roots. 相似文献
55.
不同灌水模式对小麦产量、形态和生理特性的影响 总被引:1,自引:0,他引:1
为了探寻快速筛选节水高产小麦品种的形态和生理指标,以黄淮冬麦区2003-2013国审或省审及两个对照品种共102份小麦品种为材料,设全生育期不灌水(T_0)、灌拔节水(T_1)、灌拔节+灌浆水(T_2)三种灌水模式,检测了不同灌水模式下小麦的产量、形态和生理特性及其关系。结果表明,T_1较T_0处理通过增加穗数和穗粒数提高产量,T_2较T_1处理通过增加粒重提高产量。T_1明显增加株高、旗叶的面积、周长、长和宽;T_2处理小幅增加株高,对旗叶形态影响年度间不一致。T_1和T_2处理明显增加冠层温差。T_1处理对灌浆后期小麦旗叶叶绿素含量影响年度间不一致,T_2处理提高叶绿素含量。T_0条件下,产量与冠层温差呈显著正相关;T_1条件下,产量与旗叶宽和冠层温差呈显著正相关;在T_2条件下,产量与旗叶宽、叶绿素含量和冠层温差呈显著正相关,与株高呈显著负相关。因此,冠层温差、旗叶宽和叶绿素含量可以用作筛选和鉴定相应灌水模式下节水高产小麦品种的形态或生理指标。 相似文献
56.
Maintenance of demographically and genetically self-sustaining populations in captivity can assist conservation of threatened species. Captivity can, however, lead to changes in phenotype, though to date this issue has received little attention in reptiles. We compared phenotypic differences in the now critically-endangered Otago skink (Oligosoma otagense) between wild specimens (Otago, southern New Zealand) and in captivity (North Island). Individuals of this long-lived, viviparous species have been maintained up to three generations in captivity, primarily by private herpetoculturists, but increasingly there is interest in integrating management of captive stocks with conservation in situ. For the same snout-vent length, captive skinks pooled across three colonies had a significantly heavier body mass, wider tail base, longer tail (juveniles only), faster growth rate and much slower sprint speed than in the wild. Captive skinks also lacked ectoparasitic mites and haemogregarine parasites, and experienced warmer temperatures with probably greater access to food. Our study demonstrates the importance of not treating captive management for conservation as a tool of last resort. Important questions, if captive-raised animals are to be released to the wild, are is it better for released skinks to run swiftly or to be heavy-bodied, and what role does reinfestation with native parasites have in determining this balance? We also recommend genetic analysis and studbook management of captive stocks, research to determine implications of heavy body mass for reproduction in captivity, and production of at least some offspring for release inside larger enclosures within the local climate. 相似文献
57.
Jos Manuel Cano Hannu Sakari Mkinen Tuomas Leinonen Jrg Freyhof Juha Meril 《Biological conservation》2008,141(4):1055-1066
The fact that the intraspecific genetic differentiation in neutral genetic markers and genes coding for adaptive traits are not typically correlated has caused a great deal of conceptual and practical trouble in delimitation of conservation units. Although the importance of combining information on adaptive genetic divergence with information on historical and recent gene flow in the delimitation of conservation units has been recognized, integrated empirical studies to this end are still rare. We explored the evidence for the specific conservation status of two freshwater three-spined stickleback (Gasterosteus aculeatus) populations on the Adriatic side of the Balkan Peninsula by comparing their phenotypic and genetic characteristics to those of other representative European populations. Apart from focusing on the neutral genetic divergence in mitochondrial DNA sequences and microsatellite markers, we also compared the patterns of morphological differentiation (i.e. bony armour development) resulting from adaptation to freshwater environments. The Balkanic populations formed two distinct groups with regard to neutral genetic variation and had the least developed bony armour of all the examined populations. All morphometric analyses identified the two Balkanic populations as phenotypically – and hence most likely also ecologically – clearly distinct from other European three-spined stickleback populations. These results suggest that the two Balkanic populations (River Neretva and River Zeta) fulfil the most stringent criteria (i.e. lack of genetic and ecological exchangeability) to be classified as conservation units distinct from other European three-spined stickleback populations. 相似文献
58.
Soil development along primary succession sequences on moraines of Hailuogou Glacier,Gongga Mountain,Sichuan, China 总被引:1,自引:0,他引:1
Soil properties related to soil development were measured in six profiles over approximately 180 years of soil development on recessional moraines of the Hailuogou Glacier, Sichuan of southwestern China. It is hypothesized that soil development is strictly time-dependent. Field and laboratory work indicate that as soil develops from initially coarse gravel outwash, the properties undergo a progressive physical and chemical change such that there is a considerable profile differentiation between the youngest and the oldest soils. The pH is also highly stratified; it decreases with time from 8.5 to 4.2 in the upper mineral soil and increases with depth in all profiles. Accumulation of soil organic C and N increases with time but the rates of accumulation become slower with time. Within the investigated timespan, soil C and N accumulated to a considerable level of 3.5 and 0.6 kg/m2 respectively, with mean annual rates of 28 g/m2 for carbon and 3.5 g/m2 for nitrogen. The rapid accumulation of organic C and N accelerates the processes of soil formation, but the content of organic C and N did not reach a steady-state during the observed timespan. The accumulation of soil organic matter results in increased acid production and in the chemical weathering of minerals that promote formation and translocation of the clay fraction and leaching of carbonate; it is also directly responsible for development of soil properties such as cation exchange capacity (CEC), and bulk density. 相似文献
59.
For the selection of donors with valuable characteristics for breeding, 39 thyme accessions were evaluated in three years
according to a staggered schedule. The criteria investigated were: winter hardiness, beginning of flowering, growth height,
yield of the dry herb, content of essential oil, composition of the essential oil, DNA content of cell nuclei and number of
chromosomes. The most strongly varying traits between the populations were the yield of dry herb, the content of essential
oil and the content of volatile phenols with coefficients of variation (CV) between CV 40% and 50%. The largest variation
within a population was detected for the yield of dry herb (CV 25–46%) and the content of essential oil (CV 17–48%). The homogeneity
of the populations was different. The minimal average coefficient of variation of all traits (CV 19%) was determined in the
population of the cultivar ‘Varico II’ and in a population from Lithuania. The ploidy level of T. vulgaris was diploid (2n = 30). 相似文献
60.
Bchira Zitoun Virginie Bronzini de Caraffa Jean Giannettini Catherine Breton Ahmed Trigui Jacques Maury Claude Gambotti Brahim Marzouk Liliane Berti 《Scientia Horticulturae》2008
Eighty-four olive accessions obtained from the National Conservatory of Boughrara-Sfax (Tunisia), previously evaluated for morphological traits, were analysed with 47 random amplified polymorphic DNA (RAPD) markers. They were compared with other olive genotypes originated from Eastern or Western Mediterranean. The highest and lowest similarities between genotypes, estimated by simple matching algorithm, were 0.98 and 0.40, respectively. A dendrogram based on Ward's method and a factorial correspondence analysis (FCA) showed that most of Tunisian accessions are closely related to olive genotypes originating from the Eastern Mediterranean and some are clustering with genotypes originated from the Western Mediterranean. These findings suggested multiple and complex origin of Tunisian olive. A comparative study between a previous morphological analysis and current RAPD assay was carried out and discussed. 相似文献