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1.
An investigation was carried out in the UK to determine whether intercropping with Phaseolus vulgaris beans increases the yield and nutritional quality of maize forage. Fresh and dry yields arising from different sowing dates and different densities of the two species were evaluated, with total nitrogen concentration (TNC) of the plants, and crude protein concentration (CPC), dry matter, metabolizable energy (ME), pH and starch, lactic acid and ash contents of ensiled material. Highest biomass yields of intercrops were obtained when the two species were planted simultaneously. There was a higher TNC in intercropped maize plants than in maize plants grown without beans (P < 0.05). Biomass yields were not significantly higher with a higher density of maize in the intercrop than with a lower density, nor were they higher with monocrop maize than with intercropping. However, the biomass had higher CPC at 75 000 maize plus 50 000 beans ha?1 and 50 000 maize plus 50 000 beans ha?1 than monocrop maize. Other nutritional characteristics of the silage made from the intercrop treatments were not significantly different from those of the silage made from monocrop maize. As the silage from intercrops of 75 000 maize plus 50 000 beans ha?1 and 50 000 maize plus 50 000 beans ha?1 gave more CP per land area than monocrop silage, and gave biomass yields that were not significantly different from monocrop maize, it was concluded that such intercropping is suitable for producing high‐quality silage under similar agro‐climatic conditions. Copyright © 2007 Society of Chemical Industry  相似文献   

2.
In a field experiment comparing sulphur-coated urea (SCU) and “Nitro-Chalk” at rates up to 400 kg N ha?1, potato tuber yields were greater with “Nitro-Chalk” at rates up to 200 kg N ha?1, but there was no consistent difference between forms of N at larger rates. The crop recovered more N from “Nitro-Chalk” at all rates except 350 kg N ha?1. The largest measured yield was at 200 kg N ha?1 with “Nitro-Chalk” and 250 kg N ha?1 with SCU, and the optimum N rate inferred from split-line regressions of yield on N rate was also at a lower N rate with “Nitro-Chalk”. Yields of winter wheat following the potatoes increased significantly with the N rates given to the potatoes and, at rates above 200 kg N ha?1, were larger where SCU had been used. SCU residues also lessened the response of the wheat to a spring top-dressing of new N slightly more than those of “Nitro-Chalk”. The sum of the apparent recoveries by the two crops of N given to the potatoes was greater from “Nitro-Chalk” at rates up to 200 kg N ha?1. In the glasshouse, potato plants grown in 3 kg soil took 71 days to initiate tubers when given 2 g N as ammonium nitrate but this time was much decreased as increasing proportions of SCU were used. When 1 g N was given, the time was only 47 days with ammonium nitrate and the proportion of SCU had little effect. In the field, the number of tubers per plant by mid-June decreased with increasing N rate with “Nitro-Chalk” but not with SCU.  相似文献   

3.
In Mexico the tortilla is most commonly eaten in the form of ‘taco’; this is normally accompanied with other food, in particular the common bean. Tortillas made of quality protein maize (QPM) fortified with common bean might be a strategy to improve their protein quality. In this study, amino acids and mineral changes that occur during nixtamalization and the chemical and nutritional characteristics of regular, commercial and QPM tortilla–bean combination were assessed. After nixtamalization, protein from QPM nixtamalized maize flour was reduced from 8.1% to 7.2% (w/w). Tryptophan was also reduced from 12.1 to 11.1 g kg?1 protein. QPM maize retained a higher amount (P < 0.05) of calcium (3180 mg kg?1) compared to regular maize (1820 mg kg?1). When nixtamalized maize flour of regular maize and commercial tortilla were combined with beans, protein content increased. The tryptophan and lysine contents in these tortillas were increased (P > 0.05) also, but were significantly lower (P > 0.05) than in tortilla made with QPM maize fortified with bean (22.7 and 69.9 g kg?1 protein, respectively). Mineral contents increased in tortilla–bean combination. The QPM and tortilla fortified with bean gave an improvement in protein quality and could contribute significantly towards human nutrition, especially in countries like Mexico where maize and beans are important components of the diet. Copyright © 2007 Society of Chemical Industry  相似文献   

4.
Nitrogen form affects yield and taste of tomatoes   总被引:1,自引:0,他引:1  
Different nitrogen forms in organic or mineral fertilizers affect yield, quality and taste of tomatoes. Tomato plants were grown in a greenhouse for 10 weeks and fertilized with two different organic fertilizers (manure or grass and clover mulch) or with three different mineral nutrient solutions (NO3?:NH4+) ratios 4:1 or 1:4). In an attempt to mimic the nutrient supply of the organic production systems, mineral fertilizers with ammonium as the dominating N‐source were combined with two chloride levels. Total nitrogen supply was 650 mg N plant?1 week?1 in all treatments. There was no difference in the yield of red tomatoes between the treatments (mean 1.95 kg FW plant?1). However, the yield of green tomatoes at the final harvest was significantly higher in the mineral nutrient treatments (mean 1.37 kg FW plant?1) compared with the organic treatments (mean 0.88 kg FW plant?1). Plant biomass was higher for the mineral nutrient treatments (mean 1.05 kg FW plant?1) compared with the organic treatments (0.89 kg and 0.72 kg FW plant?1 in the manure and the grass and clover mulch treatments, respectively). Significantly higher scores were achieved for sweetness, acidity, flavour and acceptance for the tomatoes grown with the organic or the ammonium‐dominated treatments compared with the tomatoes grown with the nitrate dominated nutrient solution. It is suggested that ammonium is an equivalent nitrogen source for tomato plants compared with nitrate and that, when tomato plants are supplied with reduced nitrogen forms such as ammonium or organic nitrogen, an improved tomato fruit taste can be observed. Copyright © 2005 Society of Chemical Industry  相似文献   

5.
BACKGROUND: Two field trials growing Jerusalem artichoke (Helianthus tuberosus L.) are discussed. Twenty genetic variants were compared in order to find genotypes suitable for Norwegian production. A second trial investigated the above‐ground part of early and late variants. RESULTS: The highest yield (28.7 t ha?1) and highest amount of tubers per plant was obtained in early variants, e.g. the white Tysnes gave 1.72 kg tubers plant?1. Early variants had a markedly lower portion of smooth tubers. Late variants gave the most preferable tuber shape, but low yield. Only a weak correlation was found between dry matter content and total content of fructo‐oligosaccharides (FOS) (r = 0.255) in the tubers. The mean content of FOS including sucrose through all variants was found to be 116 g kg?1 fresh weight (FW) or 550 g kg?1 dry weight (DW). The average chain length of FOS in the tubers was found to be DP3.9. There was no difference in tuber FOS content between early and late variants. The highest above‐ground amount biomass was found for the late variants when harvested in September. The content of soluble carbohydrates was found to be highest in stalks in August (sucrose and FOS major compounds). CONCLUSION: Early variants give the highest tuber yield under Norwegian growing conditions. Late variants give highest above‐ground biomass. Copyright © 2010 Society of Chemical Industry  相似文献   

6.
BACKGROUND: Bean seeds are an inexpensive source of protein. Anthracnose disease caused by the fungus Colletotrichum lindemuthianum results in serious losses in common bean (Phaseolus vulgaris L.) crops worldwide, affecting any above‐ground plant part, and protein dysfunction, inducing the synthesis of proteins that allow plants to improve their stress tolerance. The aim of this study was to evaluate the use of beans damaged by anthracnose disease as a source of peptides with angiotensin‐converting enzyme (ACE‐I)‐inhibitory activity. RESULTS: Protein concentrates from beans spoiled by anthracnose disease and from regular beans as controls were prepared by alkaline extraction and precipitation at isolelectric pH and hydrolysed using Alcalase 2.4 L. The hydrolysates from spoiled beans had ACE‐I‐inhibitory activity (IC50 0.0191 mg protein mL?1) and were very similar to those from control beans in terms of ACE‐I inhibition, peptide electrophoretic profile and kinetics of hydrolysis. Thus preparation of hydrolysates using beans affected by anthracnose disease would allow for revalorisation of this otherwise wasted product. CONCLUSION: The present results suggest the use of spoiled bean seeds, e.g. anthracnose‐damaged beans, as an alternative for the isolation of ACE‐I‐inhibitory peptides to be further introduced as active ingredients in functional foods. © 2012 Society of Chemical Industry  相似文献   

7.
Maize is considered as “life” in southern Africa because it is the staple food crop and the main component of food aid interventions. However, its productivity is very low, partly because of the limited use of external inputs. Although maize response to fertilizer has been the focus for many years of studies on research stations, information is scanty on the level of crop response and profitability on smallholder farms in most parts of southern Africa. Therefore, the objective of the present analysis was to determine yield responses, nitrogen use efficiency and returns to investment in fertilizer in the unimodal rainfall region of southern Africa. This analysis compared yield responses to various rates of nitrogen (N) fertilizer with maize grown without external inputs (absolute control) on a total of 940 demonstration sites in 47 districts across Malawi, Mozambique, Zambia and the southern highlands of Tanzania. Across the sites, average yields were 1.6 t ha?1 in the control, 2.8 t ha?1 with ≤50% of the recommended N rate and 4 t ha?1 where 100% or more of the recommended N rate was applied. Except in Zambia, agronomic efficiency and partial factor productivity of N were higher with 50% of the recommended N rate compared to 100% of the recommended N rate. Net present values (NPV) were also positive in over 50% of the cases, indicating that investments in N fertilizer will generate profits over time. In contrast, for maize grown without N fertilizer, NPVs were negative in over 68% of the cases across the four countries. The value-cost ratio was >2 with the various N rates at the aggregate level, but it was <2 on sites in Mozambique and Zambia. We conclude that growing maize without N inputs results in loss of land productivity and profitability while application of 50% or more of the recommended N fertilizer ensures substantial increases in yields and profitability.  相似文献   

8.
BACKGROUND: Foliar fertilizer methods could provide a rapid and efficient response when uptake by plant roots is limited. This work studies the effect of foliar urea sprays (15 g L?1) at different frequencies on the antioxidant metabolism and fruit quality of sweet pepper fruits under N‐limited nutrient solution (3.5 mmol L?1 NO3?) and fully N‐supplied (12.5 mmol L?1 NO3?) plants. RESULTS: Foliar applications of urea in root N‐limited plants increased the total N concentration in the fruits and no significant differences were found with respect to control fruits (plants fully supplied with N by the roots). Fruit color was significantly affected by the urea sprays, and at the highest frequency (twice a week) the largest overall color difference (ΔE) with respect the non‐sprayed fruits was obtained. Foliar urea increased anthocyanin concentration to control values but flavonoids were only affected at the highest application frequency. N deficiency induced oxidative stress but foliar application of urea altered this response, significantly diminishing catalase and ascorbate peroxidase activity. CONCLUSION: Sweet pepper fruits showed a significant and positive response to foliar fertilization on the studied parameters, compensating to a major extent the reduction of N by the roots. In addition to the environmental issues in reducing N contamination, fully monitored automatically sprayed foliar fertilizer could utilize N more efficiently and at lower cost than applying the full recommended rate of other N fertilizers to the nutrient solution, providing flexibility in correcting N nutrition in the plant, and especially the control of nutrient supply independent of the water supply. Copyright © 2008 Society of Chemical Industry  相似文献   

9.
Winter barley which received a range of nitrogen rates, was grown at Rothamsted as a test crop after winter oats, winter barley, winter beans, oilseed rape or potatoes, to compare the effects of previous crop on growth and N uptake. In the autumn following the first year crops, the largest amount of residual inorganic N found in the soil was after potatoes, the smallest after oats. Throughout the second season the heaviest crops of barley, which also contained the most N, were after potatoes, and the lightest were after barley. To produce grain with a N concentration of less than 1.8% N (w/w, dry wt), acceptable for malting, it was found that not more than 75 kg N ha−1 after barley and 125 kg N ha−1 after oats, 100 kg N ha−1 after beans and 50 kg N ha−1 after rape or potatoes could be applied. The results demonstrated that barley of acceptable quality for malting can be grown after a break crop, providing that the rate of N fertiliser is suitably adjusted to take account of the residual fertility, but the results do not suggest that residual soil N affects the grain N concentration differently to N applied as fertiliser early in the season.  相似文献   

10.
Total phenol, flavonoid and saponin content of soy bean and mung bean were systemically compared in order to evaluate their contribution to overall antioxidant activity. Mung bean extract possessed significantly higher total phenol (2.03 GAE g?1 vs. 1.13 GAE g?1) and flavonoid contents (1.49 GAE g?1 vs. 0.41 CAE g?1) than soy bean extract, while the saponin content of the soy beans was 4.5 times greater than that of the mung beans. In several antioxidant assays including DPPH and ABTS radical scavenging, FRAP, SOD‐like activity, and a β‐carotene bleaching assay, mung bean extract consistently showed significantly greater antioxidant activity than soy bean extract. The specific antioxidant activity, which was evaluated at the same phenolic content suggested that the phenolic compounds present in the mung bean extract were not only of greater quantity but also had better quality to eliminate radicals. The radical scavenging activities of saponins were only marginal.  相似文献   

11.
Nanoparticles represent a promising technology to enhance the efficacy of bioactive materials and a large number of studies showed the effectiveness of nanostructured materials against various arthropod species of economic importance. In this work nanostructured alumina (NSA) was prepared using sol-gel method and the effect of NSA was evaluated as seed protectant against the main seed-infesting insect pests Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) Stegobium paniceum (L.) (Coleoptera: Anobiidae), and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). Besides, we tested the effects of NSA on seed germination and plant growth and finally, we assessed the presence of NSA as a contaminant in the leaves of bean plants germinated from NSA-treated seeds. The results showed significant insecticidal activity of NSA against the three tested species. After sixteen days, the percentage of insect mortality at the highest NSA concentration tested (400 mg kg−1) was 100.00% for S. paniceum followed by O. surinamensis (80.64%) and T. confusum (79.41%). Besides, in-vitro tests indicated that NSA has no effects on seeds germination and on radicle and shoot elongation. No effects of NSA were also observed in pot tests on the bean’s plants. No differences were recorded in the leaves area, stoma density and roots length. On the contrary, the shoot of plants from NSA-treated beans was about 66% higher than the one of the non-treated plants (shoot, 15.07 cm for the control and 22.76 cm for NSA-treated plants). Finally, no contamination by alumina particles was found by EDX-system coupled with Scanning Electron Microscopy (SEM) on the surface of the P. vulgaris leaves obtained from NSA-treated beans. Overall, the results showed that NSA could be an effective protective agent for the control insect pests during the seeds storage.  相似文献   

12.
Spring field bean varieties contain more protein than peas, but fluctuating yields often confuse results. Peas have a higher sulphur amino acid content than beans, but potential sulphur amino acid yield ha?1 is greater in the latter. The biological value in rat feeding trials closely reflected the sulphur amino acid content. A negative correlation was found between protein sulphur amino acid content and percentage seed protein.  相似文献   

13.
African traditional weaning foods are usually prepared from starchy flours at a total solids content of 50–100 g l?1, giving a viscosity of 1000–3000 cP which is consumable by infants. These porridges have very low energy and nutrient densities. Processing to reduce the porridge viscosity and improve the energy and nutrient density may help in solving this problem. Maize, kidney bean and their 70:30 composite flours were irradiated at 0–10 kGy at room temperature. Irradiation greatly reduced the viscosity of porridges, probably by starch depolymerisation. Irradiation improved the starch digestibility of raw bean flours, possibly either by inhibiting α‐amylase inhibitors or by weakening the thick cell walls that enclose the starch granules, thus improving accessibility to enzymes. However, in raw maize, cooked maize and cooked bean flours there was maximum starch digestibility at a dose of 2.5 kGy, followed by small but significant decreases in starch digestibility at higher doses, more so in maize than in bean flours. The decrease in digestibility could be due to the formation of inhibitors of amylolytic enzymes (Maillard reactions products) or to the formation of resistant starch. Irradiation doses required to increase the total solids content of traditional maize‐ and/or bean‐based weaning porridges to at least 200 g l?1 do not compromise starch digestibility significantly. © 2001 Society of Chemical Industry  相似文献   

14.
Mechanical damage to dry kidney beans was assessed using hot and cold water soak-tests at 20 and 80°C, respectively. Damage was revealed as the middle lamella dissolved and the seed coats were released with zero order kinetics. Damage exposed in soak-tests had no cause-and-effect relationship to damage found in the cans after thermal processing. However, significant correlations were found between both kidney bean density and seed coat weight, and the proportion of damaged beans in the can after processing (P <0.01). The proportion of damaged beans found in the can after thermal processing increased significantly when the ratio of the seed coat weight to bean volume ratio was < 10 g ml?1. These two simple measurable parameters offer potential for predicting canning quality of kidney beans.  相似文献   

15.
Eight maize (Zea mays L) hybrids were grown under five N levels with or without the nitrification inhibitor, nitrapyrin (2-chloro-[6-trichloro-methyl] pyridine), to evaluate N interactions relative to yield performance, N use efficiency, grain protein concentration, and kernel texture. Results indicate that maize hybrids can be grouped into three categories based on grain yield: (1) low N-responsive types which reach their maximum yield with 134 kg ha?1 of applied N; (2) intermediate types that respond to moderate N levels (134 to 201 kg N ha?1); and (3) high N-responsive types that respond to higher levels of N (201 kg N ha?1). High N-responsive types, in general, increased yield with nitrapyrin treatment at all levels of N. Crop N utilisation efficiency for high N-responsive hybrids decreased, but was static for low N-responsive hybrids as N fertiliser increased. In general, as the grain yield of a hybrid increased in response to N, the concentration of protein in the kernel increased; although grain yields and protein concentration are negatively correlated among hybrids. Increased kernel translucence, an indicator of kernel hardness induced by N fertiliser, correlated highly positive with zein proteins. Isoelectric focusing analysis showed that increases in zein were primarily due to a quantitative increase in α- and γ-zein polypeptides. This study indicates that hybrids are different in their N requirements for maximum yield. Low N conditions not only restrict grain yield but also affect kernel textural quality.  相似文献   

16.
Nitrogen losses were measured in water draining from cut permanent grass swards growing in monolith lysimeters containing clay loam (Salop series) or silt loam (Bromyard series) soils. The swards were cut at 6-week intervals during the summer and were fertilised with calcium nitrate at rates of 0 and 400 kg N ha?1 in each of five successive years (1977–81); in the first year the fertiliser was labelled with 15N. Four differing rainfall regimes were imposed from spring to autumn in each year. Mean annual losses of nitrogen by leaching from unfertilised swards were 3.8 kg N ha?1 with mean nitrate-N concentrations in the water of about 1 mg N litre?1. In fertilised lysimeters where rainfall distribution was that of the long-term average the mean annual total nitrogen losses were 41 kg N ha?1 in the Salop soil and 15 kg N ha?1 for the Bromyard soil; mean nitrate-N concentrations were 11.6 mg N litre?1 and 5.1 mg N litre?1, respectively. Losses of nitrogen and nitrate concentrations were similar to these quantities when irrigation increased the rainfall total to 120% of average. Where a drought was imposed for 2 weeks before and after each cut, mean nitrate-N concentrations increased to 20.3 mg N litre?1 on Salop soil and 13.1 mg N litre?1 on Bromyard soils; total annual nitrogen losses were 74 kg N ha and 33 kg N ha?1, respectively. The largest losses were recorded when the drought period extended for four weeks before each cut and mean nitrate-N concentrations increases to 28.8 mg N litre?1 on Salop soil and 34 mg N litre?1 on Bromyard soil, with total annual nitrogen losses of 104 kg N ha?1 and 109 kg N ha?1, respectively. Losses of nitrogen derived from the fertiliser labelled with 15N were 7.3–8.4% of that applied in the Salop soil (29–33 kg N ha?1), with little effect by the differing rainfall distributions. On the Bromyard soil, losses were 3.7% (14 kg N ha?1) of the applied fertiliser in lysimeters not subjected to droughts. When the period of the drought extended before and after each cut, losses were 8.2% (32 kg N ha?1) and increased to 17.9% (70 kg N ha?1) when the drought period occurred entirely before each cut. Fertiliser nitrogen contributed 48–69% of the total nitrogen in drainage water from both soils in the first year.  相似文献   

17.
Selected physical and chemical characteristics of faba beans (Vicia faba L.) cv. Fiesta were studied after 12 months storage at 5, 15, 25, 37, 45 or 50 °C (±2 °C) in relation to the hard-to-cook phenomenon. In comparison with control (seeds stored at 5 °C), seeds stored at 15 and 25 °C demonstrated non-significant (p?0.05) changes in most of the physical and chemical characteristics including hydration and swelling coefficients, acid detergent fibre, lignin and tannin contents, whereas seeds stored at ?37 °C demonstrated significant changes (p?0.05). Solutes and electrolytes leaching after 18 h soaking substantially increased with increased temperature. Faba bean hardness tested by the hard-to-cook test also increased substantially with increased storage temperature. After 8 h soaking followed by 2 h cooking, the puncture force required for seeds stored at 5 °C was 3.3 N seed−1 whereas seeds stored at 50 °C required a much higher puncture force of 15.2 N seed−1. There was a high negative correlation (r2=0.98) between storage temperature and cooking ability of faba bean. Substantial increases in acid detergent fibre and lignin contents occurred with increased storage temperatures. There was a three-fold increase in lignin content of faba bean stored at 50 °C compared to those stored at 5 °C and it was correlated with bean hardness (r2=0.98). Storage at high temperatures for 12 months led to a substantial reduction in total free phenolics especially in the testa and there was a greater reduction with increasing storage temperature. Reduction in free phenolics was negatively correlated (r2=0.75) with bean hardness.  相似文献   

18.
Head weight of winter glasshouse lettuce was increased slightly by higher temperature (7°C day/4°C night and 10°C day/7°C night) and carbon dioxide enrichment (350 and 1000 μl litre?1) but, despite faster growth, plant nitrate concentration was unaffected. Addition at the lowest rate (138 kg ha?1 N) of ammonium nitrate, calcium nitrate and urea increased plant nitrate by a similar amount compared with nil fertilizer nitrogen, but addition of more fertilizer (276 kg ha?1 N) had no further effect. Urea produced a lower yield than the other two N sources. Coated controlled-release nitrogen produced both low yields and low plant nitrate concentrations because its nitrogen release rate was too slow to keep pace with plant growth. The most effective material in terms of high yield and low plant nitrate was one containing a nitrification inhibitor within the fertiliser granules.  相似文献   

19.
Baseline data and data taken both during and after a watershed development program, recording cropping activities in a semi-arid watershed in Telangana, India, were analyzed. Watershed development contributed to the sustainable yield improvement of dryland crops by rehabilitating the productive capacity of the land through water and soil conservation techniques. On the basis of long-term data collected from farm households in the watershed, we explored ways to increase crop productivity and sustainability. Investment in soil and water conservation significantly impacted agricultural development, most particularly during droughts. Farmers realized returns to land amounting to US $720 ha?1 from cotton, $295 ha?1 from flowers, $287 ha?1 from vegetables and $171 ha?1 from cereals. Mean returns to labour, irrespective of crop strategies, was $10 per person-day. Irrigation facilities in the watershed encouraged the growing of water-intensive crops but dryland crops were also more profitable as various in-situ and ex-situ interventions increased soil-moisture, providing congenial conditions for them. The responses were best during the watershed intervention period: yields of maize intercropped with pigeonpea were increased by 148 %, pigeonpea 100 %, sole sorghum 91 % and cotton 76.2 %. While droughts reduced the average share of household crop income in the non-watershed area from 44 to 12 %, this share remained unchanged at about 36 % in the watershed area. We deduce that watershed interventions have a positive influence on building resilient crop production.  相似文献   

20.
The objectives of this study were to investigate the effects of processing beans by soaking and blanching in salt solutions on the quality parameters of the common bean and, in order to obtain a dry product with a reduced cooking time using experimental design techniques. A Plackett and Burman design was used to evaluate the effects of nine factors, soaking, blanching and drying under different conditions, in bean processing. A central composite rotational 23 design was used with the factors of soaking time, concentration of NaHCO3 and drying temperature. An increase in the concentration of NaHCO3 from 0 to 4 g.100−1 mL reduced the cooking time by 10 min. However, increasing the NaHCO3 concentration increased the level of damage to the product and darkened the bean seed coat, producing greater color differences in the processed bean. The selected conditions for the production of dry quick cooking beans was a time of 13.1 h, a concentration of NaHCO3 in the soaking solution of 2.3 g.100 mL−1 and a drying temperature of 50 °C. Under the select conditions, it was possible to reduce the cooking time by 53%, with of 5.36 g.100 g−1 of damaged grains and color difference of 8.39.  相似文献   

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