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1.
研究了不施肥处理,氮磷钾配施和增施硼肥对青花菜养分吸收分配及产量和品质的影响。结果表明,现蕾期至花球膨大期,青花菜对氮、磷、钾的吸收量最大,整个生长期对钾的吸收最多,氮次之,磷最少。氮磷钾主要分配在叶片中,现蕾后逐渐向花球转移,从现蕾到采收时,叶片中氮、磷、钾分配率分别降低了19.6%、10%和9.0%,花球中氮磷钾分配率分别提高了23.1%、15.9%和11.1%。不施氮、磷、钾肥显著降低了花球产量、维生素C含量和成品率,增施硼肥处理的花球成品率较氮磷钾肥处理提高了4.8%,不施氮肥和钾硫肥(K2SO4)显著降低了花球中的硫代葡萄糖苷含量。相关性分析表明,青花菜产量与植株内氮、钾积累量显著正相关,成品率与植株内磷营养显著正相关。  相似文献   

2.
江汉平原是国家优质粮食、优质棉花和双低油菜重要生产基地,也是湖北省西瓜主产区。种植西瓜对增加农民收入、丰富市场、发展农村经济、提高土地利用率具有重要作用。江汉平原西瓜生产的突出特点是间作套种,早在20世纪70年代就推广了“麦//瓜-稻”这种水旱、粮经作物配套种植的优化模式.并获得原荆州地区科技进步二等奖。由于西瓜间作套种提高了单位面积的经济效益、  相似文献   

3.
AIM: To detect the treatment of K562 leukemia cells with bortezomib altering the expression of genes fas, bcl-2, bcl2l12, bim, bax, caspase-9 and caspase-3.METHODS: MTT assay was used to detect the inhibition of proliferation. Apoptosis was detected by Annexin-V staining and mitochondrial transmembrane potential (Δψm). RT-PCR was used to analyze the mRNA expressions of fas, bcl-2, bcl2l12, bim, bax, caspase-3 and caspase-9.RESULTS: Bortezomib caused a time- and dose-dependent inhibition of cell proliferation and IC50 of 24 h and 48 h were 161.41 nmol/L and 96.33 nmol/L, respectively. At the concentration of 104 nmol/L, bortezomib induced apoptosis in a time-dependent manner, including increasing annexin-V positivity and decreasing the Δψm. RT-PCR showed that bortezomib up-regulated the mRNA expression of fas, bcl2l12, caspase-9 and caspase-3, but mRNA expressions of bcl-2, bim and bax did not changed obviously.CONCLUSION: Bortezomib inhibits the proliferation of K562 and induces apoptosis, in which fas, bcl2l12, caspase-9 or caspase-3 gene is one of the main genes taking part in.  相似文献   

4.
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors at multiple spatial scales. The purpose of this research was to quantify spatiotemporal patterns of meadow invasion; and how climate, larger landforms, topography, and overstory trees have interactively influenced tree invasion. We combined airborne Light Detection and Ranging (LiDAR) characterizations of landforms, topography, and overstory vegetation with historical climate, field measurements of snow depth, tree abundance, and tree ages to reconstruct spatial and temporal patterns of tree invasion over five decades in a subalpine meadow complex in the Oregon Cascade Range, USA. Proportion of meadow occupied by trees increased from 8?% in 1950 to 35?% in 2007. Larger landforms, topography, and tree canopies interactively mediated regional climatic controls of tree invasion by modifying depth and persistence of snow pack, while tree canopies also influenced seed source availability. Landscape context played an important role mediating snow depth and tree invasion; on glacial landforms tree invasion was negatively associated with spring snowfall, but on debris flows tree invasion was not associated with snow fall. The importance of snow, uncertain climate change impacts on snow, and mediation of snow by interacting and context dependent factors in complex mountain terrain poses substantial hurdles for understanding how these ecotones may respond to future climate conditions.  相似文献   

5.
The aim of this research was to determine the effect of three different fertilizing systems, including organic, conventional, and integrated ones, on the yield, fruit quality, antioxidant activity, and some phenolic compounds of white seedless grape. The study was carried out on several 6-year-old white seedless grapevine located in the Urmia Province (North-West Iran). The results showed that the fruit physical characteristics and yield were affected significantly by different fertilization systems. The highest yield was observed in the conventional fertilization, followed by organic and integrated systems. The leaf mineral contents were obviously dependent on the different fertilization used, whereas pH and titratable acidity were not affected. Based on our results, the highest values of antioxidant activity and total flavonoid were found in the organic and integrated fertilization systems, respectively. Also, the highest contents of total phenolic, catechin, and quercetin-3-galactoside were observed in the organic fertilization system. Overall, the highest nutritional quality and biochemical characteristics of white seedless grape were obtained in organic fertilization system, which improved antioxidant capacity by enhancing total phenolics, total flavonoids and valuable phenolic compounds.  相似文献   

6.
Geographical perspectives of space,time, and scale   总被引:24,自引:0,他引:24  
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7.
中国''''99昆明世界园艺博览会蔬菜瓜果园   总被引:1,自引:0,他引:1  
蔬菜瓜果园作为中国’99昆明世界园艺博览会六大专题展园之一 ,占地 4 90 0m2 。园内以农舍草屋为中心 ,通过瓜架、篱笆、草亭及蔬菜瓜果栽培 ,构出一幅农家乐园式的田园风光。另外 ,通过集中展示中国蔬菜瓜果的科技生产水平 ,丰富的资源优势 ,色彩缤纷、新奇别致的蔬菜瓜果品种 ,来突出本次世博会的主题“人与自然 ,和谐发展———迈向 2 1世纪” ,从而展现“蔬菜瓜果园艺是人类赖以生存的重要食源和艺术”为主题思想的蔬菜瓜果园内涵。  蔬菜瓜果园位于世博园主入口世博大道南侧 ,与盆景园、药草园相邻。在总体布局、栽培上充分运用园…  相似文献   

8.
Two levels of N and four levels of K, applied to beds of sphagnum peat before planting (Experiment A), were tested in factorial combination with three concentrations of N (50, 175 and 300 mg 1-1) and two of K (50 and 250 mg T1) in the liquid feed. In three cucumber crops grown, Mg was supplied or omitted before planting as a split plot factor (96 subplots). In two further crops (Experiment B), grown in fresh peat, six concentrations of N (20-320 mg 1-1) were tested in the liquid feed, all other nutrient levels being constant. In Experiment A, the early yield was reduced by low and high levels of N. The main effect of N on the final yield was not significant, but maximum yield was achieved with 175-300 mg 1-1 N in the liquid feed where the peat received a small amount of ureaformaldehyde (15 g m“2) and Mg fertilizer. The N x Mg interaction became increasingly marked with successive crops; the loss in yield due to Mg deficiency (<31%) increased with the amount of N applied. K deficiency reduced the yield by up to 66%, and very high levels of K also tended to decrease the yield. The K x Mg interaction became more marked with time and the loss in yield due to Mg deficiency (<23%) increased with the amount of K applied. Leaves from N, K and Mg deficient plants contained <2.5% N, <1.0% K and <0.28% Mg respectively. In Experiment B, where N was supplied only in the liquid feed, the highest yield was obtained at 220 mg 1-1. The relation between yield and the total amount of N supplied in the feed was defined by a quadratic regression.  相似文献   

9.
盆景果树集"艺术欣赏与果实享用"于一身。文章重点阐述盆景果树的定义、发展史与现状、分类与特点、文化和经济的双重价值等内容。  相似文献   

10.
玲珑王是杂交一代西瓜新品种,早熟,全生育期100 d,果实发育期28 d.植株长势中强,低温弱光条件下坐果性好,果实商品率较高.果实椭圆形,果彤指数1.28.果皮绿底覆深绿色窄条带,皮厚约5 mm,果肉鲜红色,中心折光糖含量11.7%,肉质细脆,汁多纤维少,口感风味好.抗病性、抗逆性较强.单瓜质量1.5 kg,1 hm2产量达到33 000~58 500 kg.  相似文献   

11.
对辣木的生物学特性、栽培要点、营养与药用价值、加工与开发利用等展开论述,同时分析了我国在辣木科研和市场方面存在的问题,并对辣木未来的研究和市场应用前景提出建议和展望。  相似文献   

12.
XIE Hua  HE Shao-heng 《园艺学报》2004,20(10):1942-1946
Many nnewly discovered interleukins have been implicated to play an important role in the pathogenesis of the allergic diseases, for example, human interleukin (IL)-17, a T-cell derived cytokine; interleukin (IL)-18, an interferon (IFN)-gamma-inducing cytokine; interleukin (IL)-23, produced by activated dendritic cells, and interleukin (IL)-25, a recently described T helper 2 (Th2) cell-derived cytokine. Understanding their characteristic and roles in diseases may help us to know better the mechanism of the allergic diseases and develop the strategy for treating the disease.  相似文献   

13.
During the period 2001–2003 the performance of paclobutrazol, prohexadione-Ca, root pruning, summer pruning and deficit irrigation was studied with respect to a control in a Blanquilla pear orchard. Shoot growth, yield, fruit size, and return bloom were all evaluated.  相似文献   

14.
A field experiment was carried out with one-year-old peach trees to determine the influence of applications of nitro-chalk (N), superphosphate (P), sheep manure (SM), and a fertilizer mixture (X), in factorial combination, on tree growth during the first growing season. Fertilizers were mixed into the soil at planting sites about two weeks before tree planting.

Maximum tree growth was achieved when 3 lb. P and 36 lb. SM were applied per tree. However, all fertilizers depressed leaf bud development and early shoot growth and, in a few cases, application of 3 lb. N per tree resulted in tree death. It is concluded that heavy rates of these fertilizers should not be applied to planting sites prior to planting young peach trees. Rather, it appears from seasonal growth measurements that fertilizers should not be applied to newly planted trees until late spring (November).

The only consistent and significant interaction occurred between N and SM. Application of SM increased tree growth more in the absence of N than in its presence; i.e. the SM acted as a nitrogen source. SM depressed tree growth early in the growing season, probably because some of its components are readily soluble. However, later in the season it promoted growth and partly alleviated the detrimental effect on tree growth induced by 3 lb. N per tree. It is evident from calculated concentrations of elements per planting site that the SM treatment supplied larger quantities and a wider range of elements than the inorganic fertilizers.

In the absence of an N × SM interaction trees grew better if given nil or 1 lb. N than if they were given 3 lb. N. For some growth parameters, trees also grew significantly better if given 1 lb. N rather than nil.

Application of a fertilizer mixture containing potassium sulphate, magnesium carbonate, lime, ammonium molybdate, zinc sulphate, borax, Chel-138 iron chelate, and manganese sulphate to planting sites significantly depressed tree growth throughout the growing season, but this may have been due to molybdenum toxicity, although no visual symptoms were present.  相似文献   

15.
Fruits are important components of a healthy diet. They are a good source of vitamins, minerals, proteins, and dietary fibers. The study was carried out in the Federal University of Agriculture, Abeokuta, Ogun State, Nigeria with the major objective to analyze the determinants of fruit consumption among students. A multistage sampling procedure was used to select 100 students and data were collected with the aid of a well-structured questionnaire. The mean age was 27 years and 52% of the sampled students were male with a mean stipend of ?14,511.77 of which about ?307 is spent on fruit consumption. Apple was most preferred by the respondents due to taste. The regression analysis indicated that marital status, amount of stipend received, parental education level, availability of fruits, and nature of study were variables that significantly determine consumption of fruits among the students. Provision of physical access by giving space to either the growers or sellers of fruits in the University campus and financial access with more stipends to raise what students spent on the average per months will significantly change their fruits consumption pattern.  相似文献   

16.

Context

In the interior Northwest, debate over restoring mixed-conifer forests after a century of fire exclusion is hampered by poor understanding of the pattern and causes of spatial variation in historical fire regimes.

Objectives

To identify the roles of topography, landscape structure, and forest type in driving spatial variation in historical fire regimes in mixed-conifer forests of central Oregon.

Methods

We used tree rings to reconstruct multicentury fire and forest histories at 105 plots over 10,393 ha. We classified fire regimes into four types and assessed whether they varied with topography, the location of fuel-limited pumice basins that inhibit fire spread, and an updated classification of forest type.

Results

We identified four fire-regime types and six forest types. Although surface fires were frequent and often extensive, severe fires were rare in all four types. Fire regimes varied with some aspects of topography (elevation), but not others (slope or aspect) and with the distribution of pumice basins. Fire regimes did not strictly co-vary with mixed-conifer forest types.

Conclusions

Our work reveals the persistent influence of landscape structure on spatial variation in historical fire regimes and can help inform discussions about appropriate restoration of fire-excluded forests in the interior Northwest. Where the goal is to restore historical fire regimes at landscape scales, managers may want to consider the influence of topoedaphic and vegetation patch types that could affect fire spread and ignition frequency.
  相似文献   

17.
While studies have found that bat abundance is positively related to the amount of forest cover in a landscape, the effects of forest fragmentation (breaking apart of forest, independent of amount) are less certain, with some indirect evidence for positive effects of fragmentation. However, in most of these studies, the variables used to quantify fragmentation are confounded with forest amount, making it difficult to interpret the results. The purpose of this study was to examine how forest amount and forest fragmentation independently affect bat abundance. We conducted acoustic bat surveys at the centers of 22 landscapes throughout eastern Ontario, Canada, where landscapes were chosen to avoid a correlation between forest amount and forest fragmentation (number of patches) at multiple spatial scales, while simultaneously controlling for other variables that could affect bat activity. We found that the effects of forest amount on bat relative abundance were mixed across species (positive for Lasiurus borealis, negative for Perimyotis subflavus and Lasionycteris noctivagans). When there was evidence for an effect of forest fragmentation, independent of forest amount, on bat relative abundance, the effect was positive (Myotis septentrionalis, Myotis lucifugus and Lasiurus borealis). We suggest that the mechanism driving the positive responses to fragmentation is higher landscape complementation in more fragmented landscapes; that is, increased access to both foraging and roosting sites for these bat species. We conclude that fragmented landscapes that maximize complementation between roosting and foraging sites should support a higher diversity and abundance of bats.  相似文献   

18.
19.
Summary

Eggplant (Solanum melongena L.) is an important crop in Japan, with a long history of cultivation. Although many eggplant cultivars and lines have been developed, their nutrient concentrations, including phenolic compounds, have not been investigated in detail. In the present study, we investigated varietal differences in the concentrations of taste (e.g., soluble sugars, organic acids, and amino acids) and functional (e.g., chlorogenic acid, anthocyanins, and amino acids) compounds in eggplant fruit using 34 cultivars and lines with diverse growth habits, fruit shapes, sizes, and colours. The concentrations of taste and functional compounds differed among cultivars and lines. Variations in chlorogenic acid [0.1 – 2.5 mg g–1 fresh weight (FW)] and anthocyanin (0.0 – 0.4 A532 units g–1 FW) concentrations were greater than those of soluble sugars (e.g., sucrose, 0.5 – 1.7 mg g–1 FW; glucose, 7.6 – 13.7 mg g–1 FW; fructose, 6.2 – 15.0 mg g–1 FW) and organic acids (e.g., citric acid, 0.07 – 0.21 mg g–1 FW; malic acid, 0.9 – 1.9 mg g–1 FW). We also found that the coefficient of variation in amino acid concentrations varied with amino acid. Glutamine (27.4 – 135.8 mg 100 g–1 FW) and arginine (4.5 – 23.1 mg 100 g–1 FW) had the largest variation between varieties. These results indicate the importance of cultivar selection to optimise the concentrations of ingredients and will contribute to improvements in the functionality of eggplant through breeding.  相似文献   

20.
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