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71.
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<正>我国农作物种业发展尚处于初级阶段,表现为育种创新能力较低、种子企业竞争能力较弱、种子生产水平不高、市场监管能力不强、种业发展支持体系不健全。如何加快培育出适应我国各个地区的优良品种、提高良种在农业增产中的贡献率、提高农作物良种的覆盖率、适应中国作为世界第二大用种国的农业发展速度?从品种的选育到推广,采取品种众筹模式将是解决这一系 相似文献
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Chanda D Debnath SC Das SK Mandal TK Bhattacharyya A Choudhury A Chakraborty AK 《Journal of agricultural and food chemistry》2004,52(24):7377-7381
Disposition kinetic behavior and metabolism studies of metamitron and its metabolite in terms of the parent compound were carried out in black Bengal goats after a single oral administration of a nontoxic oral dose at 30 mg kg(-1) of body weight. Metamitron was detected in the blood sample at 5 min (2.23 +/- 0.04 microg mL(-1)), maximum at 1 h (3.43 +/- 0.02 microg mL(-1)) and minimum at 12 h (0.41 +/- 0.01 microg mL(-1)), after a single oral administration. Metabolite [3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one] in terms of the parent compound was detected in the blood sample at 5 min (0.47 +/- 0.006 microg mL(-1)), maximum at 6 h (5.12 +/- 0.02 microg mL(-1)) and minimum at 96 h (1.06 +/- 0.016 microg mL(-1)), after a single oral administration. The t(1/2 K) and Cl(B) values of metamitron were 3.63 +/- 0.05 h and 1.36 +/- 0.016 L kg(-1) h(-1), respectively, whereas the t(1/2K)(m) and Cl(B)(m) values of the metabolite were 38.15 +/- 0.37 h and 0.091 +/- 0.001 L kg(-1) h(-1), respectively, which suggested long persistence of the metabolite in blood and tissues of goat. Metamitron was excreted through feces and urine for up to 48 and 72 h, whereas the metabolite was excreted for up to 168 and 144 h, respectively. Metabolite alone contributed to 96 and 67% of combined recovery percentage of metamitron and metabolite against the administered dose in feces and urine of goat, respectively. All of the goat tissues except lung, adrenal gland, ovary, testis, and mammary gland retained the metabolite residue for up to 6 days after administration. 相似文献
75.
Muñoz AH Kubachka K Wrobel K Corona FG Yathavakilla SK Caruso JA Wrobel K 《Journal of agricultural and food chemistry》2005,53(13):5138-5143
Huitlacoche is the ethnic name of the young fruiting bodies of Ustilago maydis, a common parasite of maize. In Mexico and other Latin American countries, this fungus has been traditionally appreciated as a local delicacy. In this work a metallomics approach was used with the determination of eight elements in huitlacoche by electrothermal atomic absorption spectrometry as one facet of this approach. The results obtained indicated relatively lower concentrations of commonly analyzed metals, as referred to the data reported for other mushroom types. This effect was ascribed to different accessibilities of elements, depending on fungus substrate (lower from plant than from soil). Subcellular fractionation was accomplished by centrifugation of cell homogenates suspended in Tris-HCl buffer. Recoveries of the fractionation procedure were in the range of 71-103%. For six elements (Cr, Cu, Fe, Mn, Ni, and Pb), the mean relative contributions in cytosol, cell walls, and mixed membrane fraction were 50.7, 48.2, and 1.1% respectively. To attain the molecular weight distribution of compounds containing target elements as an additional aspect of the metallomics approach, the fungus extract (1% sodium dodecyl sulfate in Tris-HCl, 30 mmol L(-)(1), pH 7.0) was analyzed by size exclusion chromatography with UV and ICP-MS detection. With spectrophotometric detection (280 nm), the elution of high molecular weight compounds was observed in the form of one peak (MW > 10 kDa), and several lower peaks appeared at higher retention times (MW < 10 kDa). On ICP-MS chromatograms, a coelution of (59)Co, (63)Cu, (57)Fe, (202)Hg, (60)Ni, and (80)Se with the first peak on the UV chromatogram was clearly observed, indicating that a fraction of each element incorporated with high molecular weight compounds (12.7, 19.8, 33.7, 100, 19.4, and 45.8%, respectively, based on the peak area measurements). From a comparison of (80)Se and (33)S chromatograms (for sulfur analysis, the extract was obtained in the absence of SDS), both elements coeluted with the first UV peak, but their lower molecular weight compounds were apparently different. These findings may contribute to a better understanding of the accumulation of elements in mushrooms. 相似文献
76.
Sathe SK Teuber SS Gradziel TM Roux KH 《Journal of agricultural and food chemistry》2001,49(4):2043-2052
Aqueous extracts from sixty almond samples representing various genotypes and interspecies hybrids of almond, including almond-peach, were analyzed for protein and peptide content using electrophoresis, Western immunoblotting, and enzyme-linked immunosorbent assay (ELISA). Nondenaturing nondissociating polyacrylamide gel electrophoresis (NDND-PAGE) of the aqueous extracts indicated that a single major storage protein (almond major protein -- AMP or amandin) dominated the total soluble protein composition. Denaturing SDS--PAGE analyses of the aqueous extracts revealed that the AMP was mainly composed of two sets of polypeptides with estimated molecular masses in the ranges of 38--41 kDa and 20--22 kDa, regardless of the source; however, distinct variations in the intensity and electrophoretic mobility of some bands were noted between samples. In addition to AMP, several minor polypeptides were also present in all the genotypes, and variations were seen in these as well. Regardless of the genotype, AMP was recognized in Western blots by rabbit polyclonal anti-AMP antibodies, mouse monoclonal anti-AMP antibodies (mAbs), and serum IgE from patients displaying strong serum anti-almond IgE reactivity. As with protein staining results, antibody reactivity also revealed common patterns but displayed some variation between samples. An anti-AMP inhibition ELISA was used to quantify and compare aqueous extracts for various samples. All samples (n = 60) reacted in this assay with a mean +/- standard deviation (sigma n) = 0.82 +/- 0.18 when compared to reference aqueous extract from Nonpareil designated as 1.0. 相似文献
77.
Anema SG Lee SK Lowe EK Klostermeyer H 《Journal of agricultural and food chemistry》2004,52(2):337-343
Reconstituted skim milk was adjusted to pH values between 6.5 and 7.1 and heated (90 degrees C) for up to 30 min. The skim milk samples were then readjusted to pH 6.7. Acid gels prepared from heated milk had markedly higher G ' values, a reduced gelation time, and an increased gelation pH than those prepared from unheated milk. An increased pH at heating decreased the gelation time, increased the gelation pH, and increased the final G ' of acid set gels prepared from the heated milk samples. There were only small differences in the level of whey protein denaturation in the samples at different pH values, and these differences could not account for the differences in the G ' of the acid gels. The levels of denatured whey protein associated with the casein micelles decreased and the levels of soluble denatured whey proteins increased as the pH at heating was increased. The results indicated that the soluble denatured whey proteins had a greater effect on the final G ' of the acid gels than the denatured whey proteins associated with the casein micelles. 相似文献
78.
Films containing soy protein and wheat gluten were exposed to simulated farmland soil mix over a period of 30 days and monitored for degradation. The simulated farmland soil mix (topsoil/sand/Sunshine compost/vermiculite, 59:6:25:10, wt %) was mixed and stored at ambient humidity (48-55%) and temperature (20-24 degrees C); the soil mix was constantly maintained at 15% moisture by weight. Research focused on evaluating the effectiveness of gluten and cysteine additions on biodegradable behavior in the simulated farmland soil conditions. The four types of films, soy protein (S:G 1:0); soy protein with cysteine addition (S:G 1:0 + CYS); soy protein-wheat gluten (S:G 4:1); and soy protein-wheat gluten with cysteine addition (S:G 4:1 + CYS), were prepared at pH 7. 0 for degradation studies. Soy protein-gluten film rapidly degraded with 50% weight loss in about 10 days and with up to 95% weight loss in 30 days. Tensile strength and elongation of all soy protein-gluten films significantly decreased in 3 days. However, cysteine addition delayed the degradation rate of soy protein-gluten films. Soy protein-wheat gluten film disintegrated after 20 days in the simulated farmland soil environment. These results suggest that wheat gluten and cysteine addition to soy protein-based films could delay degradation rates due to their high disulfide contents. 相似文献
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Oat seeds with a higher protein content as a result of chemical applications in 1967 yielded 21 to 42 percent more grain in 1968. Wheat seed, whether from Michigan, Illinois, or Mexico, that contained more protein as a result of field applications of chemicals or nitrogen developed into larger seedlings. The content of protein in the seed correlated with subsequent growth and yield, indicating that the amount of endogenous protein or of a proteinaceous moiety, which can be controlled, may be an important factor in subsequent yield of major agronomic crops. 相似文献