Authors:X. Li, Y. Nie, X. Song, R. Zhang, and G. Wang
Different components of biodiversity may vary differently since species diversity was considered to be determined by resource availability but functional diversity was related to partitioning of niche space. Moreover, the harsh or benign conditions may result in different niche space partitioning by the coexisting species. For example, in harsh environments niche differentiation may be stronger resulting in higher functional diversity. In this study, we investigate species diversity and functional diversity along a south-to north-facing slope gradient with different resource availability in a sub-alpine meadow. Our results indicate that the patterns of species diversity and functional diversity are not consistent along this gradient. Both species richness and Shannon index of diversity increased, but functional diversity slightly decreased or changed a little from south-to north-facing slope. Moreover, these two components formed a quadratic relationship. Soil water content (SWC) was the limiting resource along this gradient. On one hand, it determined the species diversity; on the other hand, it also influenced functional diversity via affecting niche differentiation and species trait pool. In conclusion, functional diversity was determined by both species richness and niche differentiation with the influence of soil water content.
Authors:Z. Song, X. Huang, Z. Xie, Q. Ge, and R. Wang
The residual fluorine in ammonium uranyl tricarbonate (AUC) cannot be removed, while a large part of residual fluorine in
ammonium diuranate (ADU) can be removed, when AUC and ADU are decomposed and reduced under dry hydrogen atmosphere. UO2 was prepared by decomposing and reducing AUC and ADU in dry hydrogen atmosphere. The defluorination kinetics of UO2 at 500–700°C in atmosphere of 50% H2-50% H2O was investigated. The results show that the defluorination kinetics supports the Lindman's assertion that the residual fluorine
forms a solid-solution in UO2.
Some wild species of the genus Oryza such as O. rufipogon and O. longistaminata show a high level of resistance to pests and diseases including rice blast (caused by Magnaporthe grisea). To transfer blast resistance from wild species into cultivatedvarieties (O. sativa), interspecific hybrids were produced and anther culture was used toaccelerate the procedure of resistance breeding. Anther culture efficiency depended onboth the medium and the genotype of the cultivated varieties and the wild species. Afterinoculation with a mixture of six strains with wide spectrum virulence, all the F1 hybridswere resistant to blast; the F2 plants segregated, from high resistance to susceptibility, anda similar result was obtained for the H1 and H2 plants. At the H3 stage, blast resistancetended to be stable and almost 100% of inoculated H5 plants were highly resistant to riceblast. For agronomic characteristics, the F2 and H1 showed segregation, but no significantdifferences were seen between the cultivated parents and the H2 to H5 generations. Theresults demonstrate that blast resistance genes can be transferred from wild rice speciesinto cultivated varieties through crossing and anther culture, and the H5 can be used asstable lines in future breeding programmes.
Cytomixis has been described in many plant species, but not in
. The present study reports spontaneous cytomixis during microsporogenesis in
(2n = 42),
(2n = 70), and their F
hybrids with wheat. Cytomixis frequently occurred in early prophase I but very rarely in meiosis II. The type of cytomixis that occurred most often was where chromatins migrate from one nucleus into an adjacent cel1. Migration from one nucleus into two or more cells or from two or more nuclei into one cel1 was also observed. After a donor cell transferred chromatin to a recipient cell, the recipient cell would sometimes pass the chromatin on to another cell. Migration did not necessarily occur between cells in the same stage. Cytomixis in
and its hybrids with wheat was more complex than that in
. The possible causes, cytological consequences and genetic significance of cytomixis are discussed.
Authors:X. Song, G. Li, H. Zhan, C. Liu, and Z. Yang
Stripe rust, caused by Puccinia striiformis f. sp. tritici, was one of the most disaster foliar diseases for wheat-growing areas of the world. Thinopyrum intermedium has provided novel resistance genes to multi-fungal disease, and new wheat-Th. intermedium derivatives for stripe rust resistance still need to develop for wheat breeding. Wheat line X484-3 was selected from a cross between wheat line MY11 and wheat-Th. intermedium ssp. trichophorum partial amphiploid TE-1508, and was characterized by genomic in situ hybridization (GISH) and functional molecular markers. Chromosome counting revealed that the X484-3 was 2n = 44 and GISH analysis using Pseudoroegneria spicata genomic DNAas a probe demonstrated that X484-3 contained a pair of St-chromosomes from Th. intermedium donor parents. The functional molecular markers confirmed that introduced St-chromosomes belonging to linkage group 7, indicating that line X484-3 was a 7St addition line. The resistance observation displayed that the introduced Th. intermedium ssp. trichophorum derived chromosomes 7St were responsible for the stripe rust resistances at adult plant. The identified wheat-Th. intermedium chromosome 7St addition line X484-3 can be used as a donor in wheat breeding for stripe rust resistance.
Authors:X. Geng, Y. Wu, J. Song, X. Geng, J. Xing, and Z. Lei
The displacement adsorption enthalpies (ΔH) of the refolding of lysozyme (Lys) denatured by
1.8 mol L–1 guanidine hydrochloride (GuHCl)
on a moderately hydrophobic surface at 298 K, pH 7.0 and various (NH4)2SO4
concentrations were determined by using a Micro DSC-III calorimeter. The study
shows that the effect of salt concentrations on the three fractions of the
enthalpy is that with increasing (NH4)2SO4
concentrations, the molecular conformation enthalpy of the adsorbed Lys has
probably no distinct change at 1.8 mol L–1
GuHCl; the adsorption affinity enthalpy (exothermic) becomes more negative;
and the dehydration enthalpy (endothermic) decreases. At lower salt concentrations,
the dehydration, especially squeezing water molecules led by molecular conformation,
which leads to an entropy-driving process, predominates over the adsorption
affinity (also including the orderly orientation of molecular conformation),
while at higher salt concentrations, the latter is prior to the former for
contribution to ΔH and induces an
enthalpy-driving process. Also, the optimal NH4)2SO4
concentration favoring refolding and renaturing of Lys denatured by 1.8 mol
L–1 GuHCl was found.
Authors:S. Yu, A. Ren, J. Cheng, X. Song, C. Chen, and X. Wang
Effects of pH, ionic strength and fulvic acid on sorption of radiocobalt on montmorillonite and its Al-pillared and cross-linked
samples were studied using batch technique. The results indicate that the sorption of cobalt is strongly dependent on pH values
and independent of ionic strength. Fulvic acid enhances the sorption of cobalt slightly at low pH, but has no influence at
high pH values. Surface complexation is considered the main mechanism of cobalt sorption to montmorillonite. The sequences
of FA/Co2+ additions to the system did not affect cobalt sorption.
Authors:C.G. Liang, Y.X. Song, X. Guo, D. Kong, Y. Wang, Q. Zhao, and K.F. Huang
High-yield common buckwheat ‘cv. Fengtian 1’ (FT1) and tartary buckwheat ‘cv. Jingqiao 2’ (JQ2) were selected to investigate the characteristics of the grain-filling process and starch accumulation of high-yield buckwheat. FT1 had an average yield that was 43.0% higher than that of the control ‘cv. Tongliaobendixiaoli’ (TLBDXL) in two growing seasons, while JQ2 had an average yield that was 27.3% higher than that of the control ‘cv. Chuanqiao 2’ (CQ2). The Richards equation was utilized to evaluate the grain-filling process of buckwheat. Both FT1 and JQ2 showed higher values of initial growth power and final grain weight and longer linear increase phase, compared with respective control. These values suggest that the higher initial increasing rate and the longer active growth period during grain filling play important roles to increase buckwheat yield. Similar patterns of starch, amylose and amylopectin accumulation were detected in common buckwheat, leading to similar concentration of each constituent at maturity in FT1 and TLBDXL. Tartary buckwheat showed an increasing accumulation pattern of amylose in developing seeds, which differed from that of starch and amylopectin. This pattern led to a significant difference of the concentrations of amylose and amylopectin at maturity between JQ2 and CQ2, the mechanisms of which remained unclear. Nevertheless, both FT1 and JQ2 showed increased starch, amylose, and amylopectin accumulation during the physiological maturity of grains. The results suggest that prolonging the active grain-filling period to increase carbohydrate partitioning from source to seed sink can be an effective strategy to improve buckwheat yield.
Authors:X. Yu Yu, M. Song, T. Hang Hang, and A. Wen Wen
A sensitive and selective liquid chromatographic tandem mass spectrometric (LC-MS-MS) method for analysis of lovastatin in human plasma has been developed and validated. Ethyl acetate extraction was used for plasma sample preparation and simvastatin was used as internal standard. Chromatographic separation was achieved on a C18 column by isocratic elution with 83:17:0.1 (v/v) methanol-2 μM aqueous sodium acetate-formic acid as mobile phase, delivered at 1.0 mL min−1. MS-MS detection was performed using positive electrospray ionization and multiple-reaction monitoring with argon for collision-induced dissociation. Calibration plots were generated over the concentration range 0.05 to 20 ng mL−1 (r > 0.999) with a lower limit of quantification (LLOQ) of 0.05 ng mL−1. Intra and inter-day precision and accuracy were determined at four different concentrations, 0.05, 0.5, 2.0, and 10.0 ng mL−1, and precision ranged from 0.4 to 11.4% with the deviation always less than 15% (n = 5). Extraction recoveries were from 86.8 to 94.1% for lovastatin and approximately 88.0% for simvastatin. The validated method was successfully applied to a bioequivalence study of two lovastatin tablets in 20 healthy volunteers.
Authors:Y.-J. Song, S.-H. Meng, F.-D. Wang, C.-X. Sun, and Z.-C. Tan
Polyimide BTDA-ODA sample was prepared by polycondensation or step-growth polymerization method. Its low temperature heat capacities were measured by an adiabatic calorimeter in the temperature range between 80 and 400 K. No thermal anomaly was found in this temperature range. A DSC experiment was conducted in the temperature region from 373 to 673 K. There was not phase change or decomposition phenomena in this temperature range. However two glass transitions were found at 420.16 and 564.38 K. Corresponding heat capacity increments were 0.068 and 0.824 J g–1 K–1, respectively. To study the decomposition characteristics of BTDA-ODA, a TG experiment was carried out and it was found that this polyimide started to decompose at ca 673 K.