排序方式： 共有12条查询结果，搜索用时 78 毫秒
1.
2.
BACKGROUND: Isothiocyanates (ITCs) released by the enzymatic hydrolysis of glucosinolates in the Brassicaceae are potentially useful for controlling fungal pathogens. In vitro activity of pure ITCs against Sclerotinia sclerotiorum (Lib.) de Bary was studied by adding them to glass filters in petri dishes and dissolving them in the growing media. RESULTS: Methyl, allyl and benzyl ITCs were the most fungitoxic of the compounds in bioassays with S. sclerotiorum isolate Ss31. In the volatile phase, mycelial growth was completely inhibited by these three compounds. Aromatic ITCs were less toxic in the petri dishes but were more toxic than aliphatic ITCs when dissolved in the agar. Benzyl ITC exhibited the highest inhibitory effect on sclerotial germination, with an EC50 value of 75.1 µmol L?1. Butyl and benzyl ITCs reduced apothecial production of S. sclerotiorum by 92.5% at the highest concentration. In in vivo assay, only allyl and 2‐phenylethyl ITCs reduced disease incidence (by 76.7 and 70% respectively) at low concentrations. CONCLUSION: Sclerotinia sclerotiorum in the soil might be suppressed by the higher concentrations of allyl and benzyl ITCs released from decomposition of Brassica juncea, B. carinata, B. nigra and Sinapis spp. Copyright © 2011 Society of Chemical Industry 相似文献
3.
Production and characterization of films from cotton stalk xylan 总被引：1，自引：0，他引：1
Goksu EI Karamanlioglu M Bakir U Yilmaz L Yilmazer U 《Journal of agricultural and food chemistry》2007,55(26):10685-10691
Composite film production based on cotton stalk xylan was studied, and the mechanical and physical properties of the films formed were investigated. Xylan and lignin were separated from cellulose by alkali extraction and, then, lignin was removed using ethanol washing. Self-supporting continuous films could not be produced using pure cotton stalk xylan. However, film formation was achieved using 8-14% (w/w) xylan without complete removal of lignin during xylan isolation. Keeping about 1% lignin in xylan (w/w) was determined to be sufficient for film formation. Films were produced by casting the film-forming solutions, followed by solvent evaporation in a temperature (20 degrees C) and relative humidity (40%) controlled environment. The elastic modulus and hypothetical coating strength of the films obtained by using 8% xylan were significantly different from the ones containing 10-14% xylan. The water vapor transfer rates (WVTR) decreased with increasing xylan concentration, which made the films thicker. The glycerol addition as an additional plasticizer resulting in more stretchable films having higher WVTR and lower water solubility values. As a result, film production was successfully achieved from xylan, which was extracted from an agricultural waste (cotton stalk), and the film-forming effect of lignin on pure xylan has been demonstrated. 相似文献
4.
5.
Enzymatic production of xylooligosaccharides from cotton stalks 总被引：1，自引：0，他引：1
Akpinar O Ak O Kavas A Bakir U Yilmaz L 《Journal of agricultural and food chemistry》2007,55(14):5544-5551
Xylooligosaccharide (XO) production was performed from xylan, which was obtained by alkali extraction from cotton stalk, a major agricultural waste in Turkey. Enzymatic hydrolysis was selected to prevent byproduct formation such as xylose and furfural. Xylan was hydrolyzed using a commercial xylanase preparation, and the effects of pH, temperature, hydrolysis period, and substrate and enzyme concentrations on the XO yield and degree of polymerization (DP) were investigated. Cotton stalk contains about 21% xylan, the composition of which was determined as 84% xylose, 7% glucose, and 9% uronic acid after complete acid hydrolysis. XOs in the DP range of 2-7 (X6 approximately X5>X2>X3) were obtained with minor quantities of xylose in all of the hydrolysis conditions used. Although after 24 h of hydrolysis at 40 degrees C, the yield was about 53%, the XO production rate leveled off after 8-24 h of hydrolysis. XO yield was affected by all of the parameters investigated; however, none of them affected the DP of the end product significantly, except the hydrolysis period. Enzyme hydrolysis was maintained by the addition of fresh substrate after 72 h of hydrolysis, indicating the persistence of enzyme activity. The optimal hydrolysis conditions were determined as 40 degrees C, pH 5.4, and 2% xylan. The obtained product was fractionated via ultrafiltration by using 10, 3, and 1 kDa membranes. Complete removal of xylanase and unhydrolyzed xylan was achieved without losing any oligosaccharides having DP 5 or smaller by 10 kDa membrane. After a two-step membrane processing, a permeate containing mostly oligosaccharides was obtained. 相似文献
6.
The influences of fly ash and fly‐ash–quicklime‐treated‐sludge mixtures (with fly‐ash doses of 40%, 80%, and 120% on dry‐weight basis) on the microbial numbers in soil and leachate were investigated by using 60 cm soil columns. Heterotrophic bacteria and total coliform numbers were determined in soil and leachate samples following an artificial rainfall event. The results indicated that land application of untreated sludge and fly‐ash–sludge mixtures appear to introduce large numbers of bacteria to leachates and soil. Although the numbers in leachates and soils were found to decrease with increasing ash ratios, they were still all significantly above the control levels. Application of alkaline‐stabilized and pasteurized sludge did not increase bacterial numbers significantly in soil and leachate. Distribution of heterotrophic bacteria through soil profile clearly showed no increase in soils amended with alkaline‐stabilized and pasteurized sludges. Additionally, no significant inhibitory effect of lignite fly ash on soil microbial population was observed. 相似文献
7.
The study aimed to identify early‐stage traits of cotton for heat tolerance using multitrait approach reflecting field yield performance. Seedling growth and physiological response of 16 cultivars to high temperature were investigated at three different developmental stages and four heat stress conditions in a climate chamber. Some traits such as hypocotyl dry weight, leaf pigment contents and cellular respiration were significantly correlated with previously known yield of ten cultivars grown in the hot field conditions. Sixteen cotton cultivars were classified for their heat tolerance by principle component analysis (PCA) using yield‐correlated physiological traits. As a result, we showed that heat tolerance classification of cultivars based on PCA significantly coincided with the yield results of cultivars grown in hot field. As a conclusion, yield‐correlated physiological traits determined in the study may facilitate selection of heat‐tolerant cotton genotypes at early stage. In addition, yield‐correlated early‐stage traits can be used in phenotyping for QTL and association mapping studies to develop selection markers for heat tolerance. 相似文献
8.
Abiotic stress is a major limiting factor to crop productivity,and heat stress is one of the important elements for reduced crop production.Plants respond to heat stress at molecular and cellular levels as well as physiological level.Heat stress alters expression patterns of numerous genes in plants.At the molecular level,most of the information for heat stress response was obtained from model plants such as Arabidopsis thaliana,Medicago trancatula,and ,Oryza sativa,but little molecular research has focused on heat stress respones in cotton. 相似文献
9.
Kindap Tayfun Turuncoglu Ufuk Utku Chen Shu-Hua Unal Alper Karaca Mehmet 《Water, air, and soil pollution》2009,196(1-4):393-402
Water, Air, & Soil Pollution - The present paper deals with an extensive review of literature concerning the platinum group elements (PGEs), and their impact on the environment. The increased... 相似文献
10.
Kayserilioğlu BS Bakir U Yilmaz L Akkaş N 《Journal of agricultural and food chemistry》2003,51(4):964-968
The mechanical and physical properties of glycerol-plasticized wheat gluten films dried at different temperatures (20, 50, and 80 degrees C) and relative humidities (35 and 70% RH) were investigated. Dispersion of wheat gluten was prepared at pH 11 in aqueous solution. Films were obtained by casting the wheat gluten suspension, followed by solvent evaporation in a temperature and relative humidity controlled chamber. Decreasing relative humidity altered most of the mechanical properties. At 35% RH, tensile strength increased when drying temperature increased. However, at 70% RH, tensile strength decreased when temperature increased. Thickness of the films decreased by increasing temperature. Hypothetical coating strength increased with increasing drying temperature at 35% RH. However, at 70% RH, a maximum value was observed at 50 degrees C. Films produced at 80 degrees C exhibited low solubility in aqueous solution. Addition of 1.5% (w/v) sodium dodecyl sulfate increased solubility of all of the films except the film dried at 50 degrees C and 70% RH. Overall, drying temperature and relative humidity affected mechanical and physical properties of the wheat gluten films. However, the effect of drying temperature was more pronounced than the effect of relative humidity. 相似文献