首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:从到   被引次数:从到   他引次数:从到 提示：输入*表示无穷大
全文获取类型
  收费全文   18篇
  免费   0篇
专业分类
农学   3篇
  10篇
农作物   3篇
畜牧兽医   1篇
园艺   1篇
出版年
  2022年   1篇
  2019年   1篇
  2017年   1篇
  2014年   2篇
  2013年   2篇
  2012年   2篇
  2011年   1篇
  2010年   2篇
  2009年   3篇
  2006年   1篇
  2005年   1篇
  2003年   1篇
排序方式： 共有18条查询结果，搜索用时 15 毫秒
1.
This study was conducted to examine whether the applications of N-inputs (compost and fertilizer) having different N isotopic compositions (δ15N) produce isotopically different inorganic-N and to investigate the effect of soil moisture regimes on the temporal variations in the δ15N of inorganic-N in soils. To do so, the temporal variations in the concentrations and the δ15N of NH4+ and NO3− in soils treated with two levels (0 and 150 mg N kg−1) of ammonium sulfate (δ15N=−2.3‰) and compost (+13.9‰) during a 10-week incubation were compared by changing soil moisture regime after 6 weeks either from saturated to unsaturated conditions or vice versa. Another incubation study using 15N-labeled ammonium sulfate (3.05 15N atom%) was conducted to estimate the rates of nitrification and denitrification with a numerical model FLUAZ. The δ15N values of NH4+ and NO3− were greatly affected by the availability of substrate for each of the nitrification and denitrification processes and the soil moisture status that affects the relative predominance between the two processes. Under saturated conditions for 6 weeks, the δ15N of NH4+ in soils treated with fertilizer progressively increased from +2.9‰ at 0.5 week to +18.9‰ at 6 weeks due to nitrification. During the same period, NO3− concentrations were consistently low and the corresponding δ15N increased from +16.3 to +39.2‰ through denitrification. Under subsequent water-unsaturated conditions, the NO3− concentrations increased through nitrification, which resulted in the decrease in the δ15N of NO3−. In soils, which were unsaturated for the first 6-weeks incubation, the δ15N of NH4+ increased sharply at 0.5 week due to fast nitrification. On the other hand, the δ15N of NO3− showed the lowest value at 0.5 week due to incomplete nitrification, but after a subsequence increase, they remained stable while nitrification and denitrification were negligible between 1 and 6 weeks. Changing to saturated conditions after the initial 6-weeks incubation, however, increased the δ15N of NO3− progressively with a concurrent decrease in NO3− concentration through denitrification. The differences in δ15N of NO−3 between compost and fertilizer treatments were consistent throughout the incubation period. The δ15N of NO3− increased with the addition of compost (range: +13.0 to +35.4‰), but decreased with the addition of fertilizer (−10.8 to +11.4‰), thus resulting in intermediate values in soils receiving both fertilizer and compost (−3.5 to +20.3‰). Therefore, such differences in δ15N of NO3− observed in this study suggest a possibility that the δ15N of upland-grown plants receiving compost would be higher than those treated with fertilizer because NO3− is the most abundant N for plant uptake in upland soils.  相似文献   
2.
In spite of the importance of parental inheritance effects, many aspects remain inadequately explained. The objective of this study was to explore parental effects on their progeny by estimating the variability of nutritional content in peanut seeds. The peanut cv. Boreom 1 was derived from Suwon 108 (female) and Milyang 4 (male). Protein and amino acid analyses revealed that male and female parent influences on protein, Asp, Thr, Ser, Glu, Pro, Ala, Cys, Val, Met, Ile, Leu, Tyr, Phe, His, and Arg content in their progeny. The oil and fatty acid composition (C16:0, C18:0, C18:1, C18:2, C20:0, C20:1, and C22:0) of the progeny were controlled by both parental types. The synergistic interaction of female and male parental genes was also shown on sucrose and stachiyose content, while paternal effect was found on raffinose in their progeny. The antioxidant activity, daidzin, glycitin, genistin, mal-glycitin, maldaidzin, mal-genistin, and daidzein content of Boreom 1 were significantly correlated with those secondary metabolites of female parent. Our results documented that both parental genes differentially influenced on nutritional composition of their progeny, Boreom 1. This biochemical evidence of parental effects would be support to identify the suitable cultivars to improve the crop breeding.  相似文献   
3.
We investigated the effect of prohexadione-calcium (Pro-Ca) on growth characteristics and endogenous gibberellins content of Chinese cabbage grown in the alpine region of South Korea. Pro-Ca was applied at the rates of 200 ppm and 400 ppm, after 10, 15 and 20 days of transplanting seedlings in to the field. Application of Pro-Ca through foliage improved quality and quantity of yield by promoting Chinese cabbage head yield, number of head leaves, total soluble sugar content and compactness of head. The leaf size was reduced, while the chlorophyll content increased under the influence of elevated Pro-Ca application, when measured after 40 days of transplantation. The endogenous bioactive GA1 and GA4 contents of Chinese cabbage drastically decreased with elevated Pro-Ca, indicating that gibberellins (GAs) biosynthesis was blocked by this chemical. Current study suggests that both of GAs biosynthesis pathways are operational in Chinese cabbage, although non-C13-hydroxylation pathway was found to be the major pathway. GAs were quantified by gas chromatography/mass spectroscopy-selective ion monitoring (GC/MS-SIM).  相似文献   
4.
A pineapple protease, bromelain, was used to improve the dyeing properties of protein fibers such as wool and silk. The optimal condition for the activity of the pineapple protease was about 60 °C at pH 7. The wool and silk were treated with the protease extracted from a pineapple and the K/S values of the dyed wool and silk were measured using a spectrophotometer in order to compare the dye uptake. The protease treatment enhanced the dyeing properties of protein fibers without severe changes in mechanical properties. The surface appearances of protease-treated fibers were observed by microscopy.  相似文献   
5.
Nitrogen isotope abundance (?? 15N) of paddy rice (Oryza sativa L.) grown for 110?days after transplanting (DAT) under field conditions with ammonium sulfate (AS with ?0.4?? as a synthetic fertilizer), pig manure compost (PMC with 15.3?? as a livestock manure compost), and hairy vetch (HV with ?0.5?? as a green manure) was investigated to test the possible use of ?? 15N technique in discriminating organically grown from conventionally grown rice. At 15 DAT, the ?? 15N of whole rice decreased (P?<?0.05) in the order of 10.5?? for PMC > 5.5?? for control (without N input) > 4.0?? for HV > 1.8?? for AS. This difference seemed to reflect primarily the ?? 15N signal of N sources. Although differences in ?? 15N of rice grown with isotopically distinct N inputs (i.e. PMC vs. AS and PMC vs. HV) became smaller over time, the difference (2.8 and 3.0?? difference at harvest on 110 DAT, respectively) was still significant (P?<?0.05). However, there was no distinguishable difference between AS and HV treatment after 42 DAT. Such effect of N inputs on ?? 15N of whole rice was also observed for root, shoot, and grain at harvest. Therefore, our study suggests that it is possible to distinguish rice grown with manure composts from that grown with synthetic fertilizers. However, if green manure of preceding N2-fixing plants is used as the N source, ?? 15N of rice may not be a good surrogate of N sources.  相似文献   
6.
  相似文献   
7.
Plant growth promoting rhizobacteria (PGPR) has been a focus of research for its potential as an eco-friendly alternative to chemical fertilizers in the agriculture industry. In current study, the effect of culture suspension (CS) of a novel gibberellins (GAs) producing bacterial strain Burkholderia sp. KCTC 11096BP, was observed on shoot length, shoot fresh and dry biomass, root fresh and dry biomass, chlorophyll contents, endogenous bioactive GAs (GA1 and GA4) and their immediate precursors, abscisic acid (ABA), soluble sugar contents and crude protein contents of cucumber (Cucumis sativus L.). We found that growth attributes of cucumber were significantly promoted by the application of CS of Burkholderia sp. KCTC 11096BP. The quantity of GA1 and GA4 and their immediate precursors GA20 and GA9 respectively, were also significantly promoted as compared to their respective controls. Contrary to GAs, the quantity of endogenous free ABA in cucumber leaves was much lower in bacterial CS treated plants. Soluble sugar contents and crude protein contents of cucumber leaves were also significantly higher in bacterial CS treatments as compared to control. It was concluded that Burkholderia sp. KCTC 11096BP can be used as an eco-friendly bio-fertilizer in our farming systems.  相似文献   
8.
The feasibility of using kiwifruit protease as a new cosmetic material for human hair care was investigated. The effectiveness of the kiwifruit protease treatment was assessed by optical microscope examination, amino acid analysis, tensile strength changes, and dyeability test. The activated kiwifruit protease removed impurities and dirt from the hair surface without severe changes in mechanical properties. The total amino acid content of the hair samples decreased as the duration of protease treatment increased and as the treatment temperature increased. The kiwifruit protease treatment also enhanced dye uptake due to the improvement in dye accessibility to the hair via the cell membrane complex.  相似文献   
9.
Exophiala sp. LHL08, a gibberellin-producing strain, was investigated to assess its effects on cucumber plant growth and heat (40°C) stress tolerance. The results reveal that Exophiala sp. associated plants had significantly higher plant growth attributes (shoot length, plant biomass, chlorophyll contents, and leaf area) than control under heat stress. Endophytic association helped the plants to obtain adequate water to reduce the leaf electrolytic leakage under stress. High-temperature-induced oxidative stress was less pronounced in Exophiala sp. associated plants as shown by enhanced levels of total polyphenol and reduced activities of glutathione, superoxide anion, and lipid peroxidation. To tolerate heat stress and rescue plant growth, the endophyte association significantly increased catalase and peroxidase activities of the host plants as compared to control plants. Contents of palmitic, stearic, oleic, and α-linolenic were significantly decreased in the Exophiala sp.-inoculated plants than control plants under heat stress. Contents of flavonoids like genistein and daidzein were produced in higher quantities, while glycitein content was almost same in endophyte-associated plants under heat stress than control plants. Contrarily, stress-responsive endogenous abscisic acid and jasmonic acid were significantly activated in non-inoculated control treatments as compared to endophyte-inoculated plants under heat stress. The findings of the study reveal that association of Exophiala sp. with cucumber host plants can modulate heat stress by influencing physiological and biochemical contents of plants under heat stress.  相似文献   
10.
Natural abundances of carbon-13 and nitrogen-15 were analyzed in 3-year bands of annual rings of three red pine (Pinus densiflora Sieb. et Zucc.) trees in eastern Korea to elucidate their variations in relation to changing environmental conditions, particularly air pollution. Tree ring width had a trend to decrease with time (r = ?0.79, P < 0.001); however, tree-ring indices did not show any consistent pattern of change over time. Tree ring indices were correlated neither with the respective precipitation nor temperature. The δ13C (range: ?25.7 to ?24.4ä) of tree rings became less negative as tree ring indices increase (r = 0.43, P < 0.05), suggesting that radial growth of trees might have been affected by environmental factors such as nutrient deficiency and acid rain that affect carboxylation efficiency. Increasing N concentration (range: 0.40 to 0.68 g N kg?1) with decreasing δ15N (range: +4.2 to ?0.6ä) of tree rings (r = ?0.84, P < 0.01) during the period (since 1980s) of increasing NO x emission in Korea was consistent with the hypothesis that increasing deposition of N depleted in 15N may lead to 15N depletion in tree tissues. However, quantitative information on inter-ring translocation of N which may cause N isotopic fractionation is necessary to use the δ15N signal as a reliable indicator of air pollution.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号