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1.
Sodium cellulose carbonate (CC-Na) dissolved in 8.5 wt% NaOH/ZnO (100/2–3, w/w) aqueous solution was spun into some acidic coagulant systems. Diameter of regenerated cellulose fibers obtained was in the range of 15–50μm. Serrated or circular cross sectional views were obtained by controlling salt concentration or acidity in the acid/salt/water coagulant systems. Velocity ratio of take-up to spinning was controlled up to 4/1 with increasing spinning velocity from 5 to 40 m/min. Skin structure of was developed at lower acidity or higher concentration of coagulants. Fineness, tenacity and elongation of the regenerated cellulose fibers were in the range of 1.5–27 denier, 1.2–2.2 g/d, and 8–11.3%, respectively. All of CC-Na and cellulose fibers spun from CC-Na exhibited cellulose II crystalline structure. Crystallinity index was increased with increasing take-up speed.  相似文献   

2.
《Plant Production Science》2013,16(4):386-396
Abstract

The effects of elevated CO2 (approximate doubling of atmospheric CO2 concentration) on the rate of photosynthesis estimated from continuous monitoring of CO2 exchange in whole plants were investigated in radish cv. Kosena accompanied with simultaneous analysis of growth for 6 days from 15 to 21 days after planting (DAP). The elevated CO2 increased the dry weights of hydroponically grown radish plants by 59% at 21 DAP.

The increase in dry weight was due to a combined effect of increased leaf area and increased photosynthetic rate per unit leaf area. Leaf area and the photosynthetic rate were increased by elevated CO2 by 18-43% and 9-20%, respectively, during 15 to 21 DAP. Namely, an increase in the rate of photosynthesis is accompanied by an increase in leaf area, both having a significant effect on biomass production.  相似文献   

3.
Corn grits and corn fiber mixed at different mass ratios (0/100, 15/85 and 30/70) were extruded at different melt temperature (90, 105 and 120 °C) using extrusion with and without CO2 injection. The L value, reducing sugar content and antioxidant properties decreased after extrusion with or without CO2 injection. The color and antioxidant properties were relatively stable in the extrusion with CO2 injection at higher melt temperature (120 °C) in comparison with the extrusion without CO2 injection. Higher corn fiber content resulted in less loss of total phenolic content. The b, ΔE values and water absorption index increased after extrusion. The increase of the water absorption index was higher after the extrusion process with the CO2 injection especially at the lower melt temperature. The addition of corn fiber decreased L, b, and ΔE values, but significantly increased antioxidant properties under the same extrusion conditions.  相似文献   

4.
The objective of this study was to identify physiological processes that result in genotypic and N fertilization effects on rice yield response to elevated atmospheric CO2 concentrations ([CO2]). This study conducted growth and yield simulations for 9 rice genotypes grown at 4 climatically different sites in Asia, assuming the current atmospheric [CO2] (360 ppm) and elevated [CO2] (700 ppm) using 5 levels of N fertilizer (4, 8, 12, 16, 20 g m−2 N fertilizer). A rice growth model that was developed and already validated for 9 different genotypes grown under 7 sites in Asia was used for the simulation, integrating additional components into the model to explain the direct effect of [CO2] on several physiological processes. The model predicted that the relative yield response to elevated [CO2] (RY, the ratio of yield under 700 ppm [CO2] to that under 360 ppm [CO2]) increased with increasing N fertilizer, ranging from 1.12 at 4 g m−2 N fertilizer to 1.22 at 20 g m−2 N fertilizer, averaged overall genotypes and locations. The model also predicted a large genotypic variation in RY at the 20 g N treatment, ranging from 1.08 for ‘WAB450-I-B-P-38-HB’ to 1.41 for ‘Takanari’ averaged overall locations. Combining all genotypes grown at the 5N fertilization conditions, a close 1:1 relationship was predicted between RY and the relative [CO2] response in spikelet number for crops with a small number of spikelets (less than 30,000 m−2) under the current atmospheric [CO2] (n = 18, r = 0.89***). In contrast, crops with a large number of spikelets under the current atmospheric [CO2] showed a significantly larger RY than the relative [CO2] response for spikelet number per unit area. The model predicted that crops with a larger number of spikelets under the current atmospheric [CO2] derived great benefit from elevated [CO2] by directly allocating increased carbohydrate to their large, vacant sink, whereas crops with a smaller number of spikelets primarily required an increased spikelet number to use the increased carbohydrate to fill grains. The simulation analyses suggested that rice with a larger sink capacity relative to source availability under the current atmospheric [CO2] showed a larger yield response to elevated [CO2], irrespective of whether genotype or N availability was the major factor for the large sink capacity under the current [CO2]. The model predicted that the RY response to nitrogen was brought about through the N effects on spikelet number and non-structural carbohydrate accumulation. The genotypic variation in RY was related to differences in spikelet differentiation efficiency per unit plant N content. Further model validation about the effects of [CO2] on growth processes is required to confirm these findings considering data from experimental studies.  相似文献   

5.
Spring wheat (Triticum aestivum L.) was grown in a free-air carbon dioxide (CO2) enrichment (FACE) field experiment. Grain and biomass yield and its components were determined at maturity and the grain metabolome was analysed by gas chromatography-mass spectrometry (GC–MS). Elevated CO2 (537 versus 409 μl l−1) increased biomass production except for leaves. In total, levels of 16 grain metabolites were decreased and four were increased. CO2 enrichment resulted in significant decreases of amino acids such as o-acetyl-L-homoserine, leucine, arginine, L-homoserine and the group of ornithine, arginine and citrulline and negative trends for norleucine, L-aspartate, proline, L-cysteine and tyrosine. The amines D/L-diaminopimelate and alpha-ketoaminobutyrate and the polyamine putrescine were significantly decreased. In contrast, the polyamine spermidine tended to increase under elevated CO2. Among sugars and sugar derivatives, ribose-5-P was significantly increased, while gluconate-6-P was decreased. There were also negative CO2-induced effects on sugar alcohols: significant for glycerol-2-P (P = 0.008) and almost significant for myo-inositol-P (P = 0.066). In contrast, organic acids such as pyruvate and glucuronic acid were significantly increased. Overall, the N-rich metabolites especially were reduced. CO2 enrichment can markedly affect the physiology and metabolome of mature grains which may in turn lead to changes in nutritional status.  相似文献   

6.
The aim of this study was to investigate the effects of different variables on lysine loss as determined by furosine content in corn-based extrudates. Three formulations were prepared to study the effects of different chemical leavening agents, processing conditions (feed moisture content: 22, 24 or 26%; exit die temperature: 110 or 150 °C), and extrusion cooking methods (with/without CO2 injection) on furosine formation. Furosine levels of extrudates from both extrusion methods decreased around 20% when feed moisture content was increased from 22% to 26%. Amadori compounds (precursor of furosine) are formed in the early stages of the Maillard reaction, and later they are converted to further products. Consequently, furosine contents of extrudates significantly decreased as exit die temperature increased from 110 to 150 °C. Furosine contents of extrudates produced with sodium- and ammonium-bicarbonate at 150 °C exit die temperature significantly decreased, while the ones produced at 110 °C significantly increased. This may be due to accelerated formation of fructosyllysine at higher pH values followed by early degradation at 150 °C. The CO2 injection method did not have a significantly different effect on furosine content of extrudates than that produced by the conventional extrusion method, but had a positive effect on the physical properties of extrudates.  相似文献   

7.
Cowpea is a major food legume in Africa with relatively little information on N and C nutrition under field conditions in the continent. The aim of this study was to assess the relationship between leaf symbiotic N nutrition and photosynthetic carbon assimilation in cowpea genotypes grown under field conditions in the Guinea savanna of Ghana. The experiments were conducted in a randomized complete block design in Ghana, using 30 nodulated cowpea genotypes. Data collected from gas-exchange studies showed that genotypes with high photosynthetic rates expectedly exhibited greater stomatal conductance, high transpiration rates and increased water-use efficiency, leading to greater dry matter yield. In contrast, those with low photosynthetic rates revealed low stomatal conductance, low transpiration rates and low water-use efficiency. Quantification of symbiotic N in photosynthetic leaves indicated greater N2 fixation in genotypes with higher photosynthetic rates, leaf transpiration and better water-use efficiency. Furthermore, measurement of C in leaves also indicated greater accumulation in genotypes with higher symbiotic N yield and total N, clearly indicating a link between C and N metabolism in photosynthetic leaves. Additionally, measures of photosynthetic N-use efficiency showed that genotypes with high levels of C-fixed per unit leaf total N also exhibited greater C-fixed per unit leaf N-fixed. Data suggest that where symbiotic legumes derive a large proportion of their N from N2 fixation, photosynthetic C yield is much enhanced.  相似文献   

8.
《Plant Production Science》2013,16(4):233-239
Summary

Photosynthetic ability in terms of CO2 exchange rate and leaf area, dry matter accumulation (dry weight) and other important growth components along with yield and yield contributing characters in two F1 hybrids of Akebono × Chiyonishiki (A × C) and Zenith × Akebono (Z × A) were studied. The photosynthetic rate at the flowering stage was lower than that at the panicle initiation stage in all the inbred parent cultivars and F1 hybrids. Heterosis in photosynthetic rate was higher at the panicle initiation stage than that at the flowering stage. Pre-anthesis leaf area in the F1 hybrid was significantly larger than that in the parent cultivars. However, the post- anthesis decline in leaf area was more rapid in the F1 hybrids than in the parent cultivars and its magnitude was the highest in the F1 hybrid of Z × A which was tall having long and curved panicles. Pre-anthesis dry matter accumulation in both hybrids was significantly higher in the F1 plants than the parental cultivars, but post-anthesis dry matter accumulation in the F1 hybrid was lower than the mid-parental value in Z × A. The degree of heterosis in grain yield varied with the hybrid combination, an average heterosis being 1.03. Heterosis in grain yield was closely associated with heterosis in harvest index.  相似文献   

9.
The present study investigated the effects of elevated carbon dioxide concentration ([CO2]) and air temperature on the germination of seed bulbils and the seedling vigour of two Chinese yam lines. Plants were grown under two [CO2] levels, ambient and elevated (ambient + 200 μmol mol?1), and two mean air temperature regimes, 22.2 °C (ambient + 1.4 °C) and 25.6 °C (ambient + 5.2 °C). Elevated [CO2] did not affect bulbil germination under both air temperature regimes. During the early growth stage, the dry weight (DW) of leaves, vines, shoots, roots, belowground parts (roots + tubers) and whole plants were higher under elevated [CO2] than ambient [CO2] for both lines under the low- and high-temperature regimes. The values of vigour indexes (index I = germination % × seedling length and index II = germination % × seedling DW) were also higher under elevated [CO2] than ambient [CO2] for both lines. These results indicated that Chinese yam seedlings respond positively to elevated [CO2] during the early growth stage. The above:belowground DW ratios were lower under elevated [CO2] than ambient [CO2] in seedlings with very small new tubers for both yam lines, indicating that elevated [CO2] strongly affected the root growth in the early growth stage. The DWs of post-treatment seed bulbils were higher in the elevated [CO2] under both air temperature regimes. The results showed that Chinese yam used a smaller amount of the reserves in seed bulbils under elevated [CO2] than under ambient [CO2].  相似文献   

10.
ABSTRACT

Overexpression of Rubisco small subunit (RbcS) of C4 plant, sorghum (sorghum bicolor) was shown to enhance the catalytic turnover rate (k cat) of Rubisco in rice (Oryza sativa). In this study, the effects of other Rubisco small subunits of C4 plants, Napier grass (Pennisetum purpureum) and guinea grass (Megathyrsus maximus) on kinetic properties of Rubisco in rice were studied. The expression levels of Napier grass RbcS (NgRbcS) and guinea grass RbcS (GgRbcS) proteins accounted for 41% and 45% of total RbcS, respectively in homozygous overexpression lines. The k cat and K m for CO2 (Kc) of Rubisco were increased in all transgenic lines. Interestingly, the k cat was markedly higher in NgRbcS homozygous line, whereas K c was notably higher in GgRbcS homozygous line. Although its effects depend on species, these results suggest that the introduction of C4 RbcS are effective approaches to alter the catalytic properties of Rubisco in rice.  相似文献   

11.
Gloiopeltis tenax (G. tenax) is widely distributed along the Chinese coastal areas and is commonly used in the treatment of diarrhea and colitis. This study aimed at investigating the bioactivities of the volatile constituents in G. tenax. We extracted the essential constituents of G. tenax by supercritical carbon dioxide extraction (CO2-SFE), then identified and analyzed the constituents by gas chromatography-mass spectrometry (GC-MS). In total, 30 components were identified in the G. tenax extract. The components showed remarkable antioxidant activity (radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH)), lipid peroxidation inhibition capacity (in a β-carotene/linoleic acid-coupled oxidation reaction), and hydroxyl radical-scavenging activity (by deoxyribose degradation by iron-dependent hydroxyl radical), compared to butylated hydroxytoluene. In microdilution assays, G. tenax extracts showed a moderate inhibitory effects on Staphyloccocus aureus (minimum inhibitory concentration (MIC) = 3.9 mg/mL), Enterococcus faecalis (7.8 mg/mL), Pseudomonas aeruginosa (15.6 mg/mL), and Escherichia coli (3.9 mg/mL). Antioxidant and antimicrobial activities of G. tenax were related to the active chemical composition. These results suggest that the CO2-SFE extract from G. tenax has potential to be used as a natural antioxidant and antimicrobial agent in food processing.  相似文献   

12.
Sugarcane (Saccharum spp.) is an economical crop in the tropical and subtropical countries. However, because of global climate change, flooding has become problematic, particularly during the rainy season, in Thailand. We investigated the effects of floods on three commercial sugarcane cultivars, namely NiF8, U-thong 6 (UT6), and U-thong 9 (UT9), as well as Erianthus spp. Growth was assessed using a pot experiment in a glasshouse with two treatments: (1) control and (2) 60 d of flooding followed by 30 d of normal conditions. In comparison with control, during prolonged flooding, Erianthus showed greatly decreased CO2 assimilation, whereas NiF8, UT6, and UT9 showed slightly declined CO2 assimilation. Growth in plants subjected to 60 d of flooding was less influenced by floods while sucrose content was not affected except in UT6. During flooding, some roots died, resulting in plants compensating adventitious roots to offset the negative effects of root death and to assist them in maintaining their growth, which appeared from the submerged nodes, with different characteristics for each cultivar. However, 30 d after draining, roots remained damaged, while adventitious roots died, resulting in lesser growth as compared with the control, but it did not significantly affect sucrose content and sugar yield. This study suggests that sugarcane plants need to produce the adventitious roots to compensate their roots’ death during flooding and require time to recover their root system after flooding for obtaining the optimum yield and quality at harvest.  相似文献   

13.
Global climate change will result in extreme environments, such as droughts and floods. We investigated the individual and combined effects of droughts and floods of varying duration on sugarcane (Saccharum spp.) growth using a pot experiment under glasshouse conditions with the following six treatments: drought for 15 d, prolonged drought for 30 d, flood for 15 d, prolonged flood for 30 d, short flood followed by prolonged drought, and prolonged flood followed by prolonged drought. Plants that were subjected to drought conditions, including drought after a flood, had reduced CO2 assimilation (through stomatal closure) and leaf areas, whereas flood conditions showed no effect. During flooding, some roots died, and adventitious roots with well-developed aerenchyma appeared from the submerged nodes. At the time of harvest, there were no significant differences in stem fresh weight, sucrose content, or sugar yield between the treatments. However, ion content analysis revealed that flood conditions caused an accumulation of sodium in the bottom of stems and adventitious roots. Therefore, under flood conditions, plants may develop adventitious roots, which may offset the negative effects of root death, helping them to maintain their growth and yield.  相似文献   

14.
15.
《Plant Production Science》2013,16(2):156-167
Abstract

We tested the hypothesis that elevated CO2 concentration [CO2]-induced enhancement of biomass production of soybean is greater in a genotype that has a higher nitrogen (N) fixation capacity. Furthermore, we analyzed theinteractive effects of N fertilization, temperature and [CO2] on biomass production. Three genetically related genotypes: Enrei (normally-nodulating genotype), Kanto 100 (supernodulating genotype), and En1282 (non-nodulating genotype) were grown in pots, with or without N fertilizer for two years (2004, 2005). They were then subjected to two different [CO2] (ambient and elevated (ambient + 200 ?mol mol-1)) × two temperature regimes (low,high (low + 4~5ºC)). Top dry weight at maturity was the greatest in the elevated [CO2] × high temperature regime, irrespective of genotype and N fertilization. The [CO2] elevation generally enhanced N acquisition and dry matter production during the vegetative growth stage, and the enhancement was more pronounced in the nodulating genotypes (Enrei and Kanto 100) than in the non-nodulating genotype (En1282), indicating that N supply through N fixation contributes to elevated [CO2]-induced biomass production in soybean. However, the relative responsiveness ofbiomass production to elevated [CO2] was not necessarily higher in the supernodulating genotype than the normally-nodulating genotype. The N utilization efficiency to produce biomass was inferior in the supernodulating genotype than in the normally-nodulating and non-nodulating genotypes. These results did not fully verify the hypothesis that elevated [CO2]-induced enhancement of biomass production of soybean is greater in a genotype with a higher N fixation capacity.  相似文献   

16.
Over time, the relative effect of elevated [CO2] on the photosynthesis and dry matter (DM) production of rice crops is likely to be changed with increasing duration of CO2 exposure. However, there is no systemic information on interactive effects of elevated [CO2] and nitrogen (N) supply on seasonal changes in phosphorus (P) nutrient of rice crops. In order to investigate the interactive effects of these two factors on seasonal changes in plant P concentration, uptake, efficiency and allocation, a free-air CO2 enrichment (FACE) experiment was conducted at Wuxi, Jiangsu, China, in 2001–2003. A japonica cultivar with large panicle was grown at ambient or elevated (ca. 200 μmol mol−1 above ambient) [CO2] and supplied with three levels of N: low (LN, 15 g N m2), medium (MN, 25 g N m2) and high N (HN, 35 g N m2 (2002, 2003)). The MN level was similar to that recommended to local farmers. FACE significantly increased shoot P concentration (dry base) over the season, the average responses varied between 7.3% and 16.2%. Shoot P uptake responses to FACE declined gradually with crop development, with average responses of 57%, 51%, 37%, 26% and 11% on average during the growth periods from transplanting to early-tillering (Period I), early-tillering to mid-tillering (Period II), mid-tillering to panicle initiation (Period III), panicle initiation to heading (Period IV) and heading to grain maturity (Period V), respectively. Seasonal changes in shoot P uptake ratio (i.e., the ratio of shoot P uptake during a given growth period to final shoot P acquisition at grain maturity) responses to FACE followed a similar pattern to that of shoot P uptake, with average responses of 19%, 14%, 3%, −5% and −16% in Periods I, II, III, IV and V of the growth period, respectively. As a result, FACE enhanced shoot P uptake by 33% at grain maturity. P allocation patterns among above-ground organs were not altered by FACE before heading, but it was modified after heading, with a shift in P allocation patterns towards vegetative organ. FACE resulted in the significant decrease in P-use efficiency for biomass across the season and P-use efficiency for grain yield and P harvest index at grain maturity. Generally, there were no interactions between [CO2] and N supply on above P nutrient variables measured. Data from this study has important implications for P management in rice production systems under future elevated [CO2] conditions.  相似文献   

17.
The increase in atmospheric CO2 concentration [CO2] has been demonstrated to stimulate growth of C3 crops. Although barley is one of the important cereals of the world, little information exists about the effect of elevated [CO2] on grain yield of this crop, and realistic data from field experiments are lacking. Therefore, winter barley was grown within a crop rotation over two rotation cycles (2000 and 2003) at present and elevated [CO2](375 ppm and 550 ppm) and at two levels of nitrogen supply (adequate (N2): 262 kg ha−1 in 1st year and 179 kg ha−1 in 2nd year) and 50% of adequate (N1)). The experiments were carried out in a free air CO2 enrichment (FACE) system in Braunschweig, Germany. The reduction in nitrogen supply decreased seasonal radiation absorption of the green canopy under ambient [CO2] by 23%, while CO2 enrichment had a positive effect under low nitrogen (+8%). Radiation use efficiency was increased by CO2 elevation under both N levels (+12%). The CO2 effect on final above ground biomass was similar for both nitrogen treatments (N1: +16%; N2: +13%). CO2 enrichment did not affect leaf biomass, but increased ear and stem biomass. In addition, final stem dry weight was higher under low (+27%) than under high nitrogen (+13%). Similar findings were obtained for the amount of stem reserves available during grain filling. Relative CO2 response of grain yield was independent of nitrogen supply (N1: +13%; N2: +12%). The positive CO2 effect on grain yield was primarily due to a higher grain number, while changes of individual grain weight were small. This corresponds to the findings that under low nitrogen grain growth was unaffected by CO2 and that under adequate nitrogen the positive effect on grain filling rate was counterbalanced by shortening of grain filling duration.  相似文献   

18.
Failures in agricultural development in parts of West Africa may have been caused by the inability of the farmers to develop the abundant inland valleys for cultivation of such crops like rice, using appropriate water management systems. An inland valley in southeastern Nigeria was used to evaluate the influence of sawah and non-sawah water management using inorganic and organic soil amendments on the soil chemical properties and rice grain yield. Soil chemical properties tested were soil organic carbon, total nitrogen, pH, exchangeable K+, Ca2+ and Mg2+. Others were CEC, percent base saturation and exchangeable acidity while the grain yield of rice was also measured. The soils are loose, low in pH and poor in plant nutrient elements. In spite of that, the sawah-managed system was able to improve the pH of the soil by raising it slightly both in the first and second year of planting. Generally, essential plant nutrients such as exchangeable K+, Ca2+ and Mg2+, including fertility index like the CEC, were improved within sawah management within the period. Also, rice grain yield increased significantly (5.62 and 6.25 tons/ha in the first year and 5.32 and 6.53 tons/ha in the second year for non-sawah and sawah, respectively) with sawah system such that about 11 and 23% yield increases were obtained in sawah over the non-sawah in the two years, respectively. Although organic carbon can be used to explain the variation in total grain yield in the first year, it was the CEC that explained the total grain yield in the second year. The study revealed the superiority of sawah over non-sawah in the production of lowland rice in an inland valley in southeastern Nigeria.  相似文献   

19.
The present study describes the role of different exogenous hormones on morphology and plumbagin production in Plumbago indica hairy roots. It was also aimed to conserve elite root clones via synthetic seed technology. Insertion of rolB gene in transformed roots was confirmed by polymerase chain reaction followed by southern blot analysis. Hairy roots were treated with single or in combination of different phytohormones viz. IAA, IBA, 2, 4-D, NAA, BAP, GA3 and ABA. Cultures incubated with GA3 (0.5 mg l−1) yielded highest root growth due to formation of profuse lateral branching while NAA (0.5 mg l−1) treatment caused highest plumbagin accumulation. Cultures incubated with 2, 4-D exhibited highest inhibitory effect in terms of both root growth and plumbagin production. All phytohormones were found to be effective at lower concentration. In combinatorial study, GA3 + NAA (0.5 mg l−1, each) was found optimum for root biomass and plumbagin production at earlier stage of culture. Different combinations of auxins and BAP induced different morphologies ranging from reduction of lateral branching to rapid disorganization of root matrix. The combinations of ABA and selected auxins were not found promising at any of selected concentration. Based on the effect of exogenous hormones on hairy root culture, elite root clones were selected and encapsulated with sodium alginate matrix. Uniform shaped alginate coated synthetic seeds were conserved up to 6 months exhibited high regeneration potential without disturbing plumbagin content.  相似文献   

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