砂姜黑土玉米秸秆有机碳的矿化特征

 【目的】探讨不同温度（10℃、20℃、30℃）、不同秸秆加入量（秸秆全量和过量）条件下,玉米秸秆还田对土壤有机碳矿化特征及其环境因子的响应机制。【方法】采用室内恒温控湿好气培养试验,对安徽淮北砂姜黑土在不同温度（10℃、20℃、30℃）条件下,设置50 g土样中加秸秆0.3 g（处理Ⅰ）、1.5 g（处理Ⅱ）、3.0 g（处理Ⅲ）及不加秸秆（CK）的处理,进行240 d的矿化培养。【结果】温度对有机碳矿化影响显著,在对照（CK）和秸秆加入量相同的处理中,有机碳的矿化累积量均随温度（10—30℃）升高而增加;温度较低（＜20℃）时,CK、Ⅰ、Ⅱ、Ⅲ各处理的有机碳矿化温度系数（Q10）平均值约为1.229、1.251、1.572、1.399,温度较高（＞20℃）时,CK、Ⅰ、Ⅱ、Ⅲ的Q10平均值约1.006、1.249、1.401、1.374,Q10值在温度较低时大于温度较高时,说明低温条件下,有机碳矿化速率对升温更敏感。同一温度条件下,不同处理秸秆加入量越大,有机碳矿化累积量越高,有机碳矿化的日变化量也越大。本试验中,一级动力学方程能较好地描述了不同处理土壤有机碳的矿化累积动态。土壤有机碳的潜在矿化量（C0）随温度变化不明显,在同一温度条件下,秸秆加入量越大,C0值越大。【结论】一级动力学方程能较好地描述不同处理土壤有机碳的矿化累积动态。不同温度、不同秸秆还田量及温度和秸秆还田量的交互作用,对玉米秸秆矿化过程中土壤有机碳含量的影响均达到显著水平。     

Quantitative analysis of minerals and electric conductivity of red grape homogenates by near infrared reflectance spectroscopy

The use of near infrared (NIR) reflectance spectroscopy to measure the concentration of minerals and electric conductivity (EC) in red grape homogenates was investigated. Wine grape samples (n = 209) from two vintages, representing a wide range of varieties and regions were analysed by Inductively Coupled Plasma Optical Emission Spectrometry (ICPOES) for the concentrations of calcium (Ca), potassium (K), magnesium (Mg), phosphorus (P), sulphur (S), iron (Fe), and manganese (Mn) and scanned in reflectance in a NIR instrument (400-2500 nm). The spectra were pre-processed using multiple scatter correction (MSC) before developing the calibration models using partial least squares (PLS) regression and cross validation. Coefficients of determination in cross validation (R²) and the standard errors of cross validation (SECV) obtained were for Fe (0.60 and 1.49 mg kg⁻¹), Mn (0.71 and 0.41 mg kg⁻¹), Ca (0.75 and 60.89 mg kg⁻¹), Mg (0.84 and 12.93 mg kg⁻¹), K (0.78 and 285.34 mg kg⁻¹), P (0.70 and 40.19 mg kg⁻¹), S (0.88 and 14.45 mg kg⁻¹) and EC (0.87 and 7.66 mS). The results showed that Mg, S and EC in grape berries might be measured by NIR reflectance spectroscopy.     

Therapeutic Potential and Nutraceutical Profiling of North Bornean Seaweeds: A Review

Malaysia has a long coastline surrounded by various islands, including North Borneo, that provide a suitable environment for the growth of diverse species of seaweeds. Some of the important North Bornean seaweed species are Kappaphycus alvarezii, Eucheuma denticulatum, Halymenia durvillaei (Rhodophyta), Caulerpa lentillifera, Caulerpa racemosa (Chlorophyta), Dictyota dichotoma and Sargassum polycystum (Ochrophyta). This review aims to highlight the therapeutic potential of North Bornean seaweeds and their nutraceutical profiling. North Bornean seaweeds have demonstrated anti-inflammatory, antioxidant, antimicrobial, anticancer, cardiovascular protective, neuroprotective, renal protective and hepatic protective potentials. The protective roles of the seaweeds might be due to the presence of a wide variety of nutraceuticals, including phthalic anhydride, 3,4-ethylenedioxythiophene, 2-pentylthiophene, furoic acid (K. alvarezii), eicosapentaenoic acid, palmitoleic acid, fucoxanthin, β-carotene (E. denticulatum), eucalyptol, oleic acid, dodecanal, pentadecane (H. durvillaei), canthaxanthin, oleic acid, pentadecanoic acid, eicosane (C. lentillifera), pseudoephedrine, palmitic acid, monocaprin (C. racemosa), dictyohydroperoxide, squalene, fucosterol, saringosterol (D. dichotoma), and lutein, neophytadiene, cholest-4-en-3-one and cis-vaccenic acid (S. polycystum). Extensive studies on the seaweed isolates are highly recommended to understand their bioactivity and mechanisms of action, while highlighting their commercialization potential.     

Polyhydroxy p-Terphenyls from a Mangrove Endophytic Fungus Aspergillus candidus LDJ-5

Six undescribed polyhydroxy p-terphenyls, namely asperterphenyllins A–F, were isolated from an endophytic fungus Aspergillus candidus LDJ-5. Their structures were determined by NMR and MS data. Differing from the previously reported p-terphenyls, asperterphenyllin A represents the first p-terphenyl dimer connected by a C-C bond. Asperterphenyllin A displayed anti-influenza virus A (H1N1) activity and protein tyrosine phosphatase 1B (PTP1B) inhibitory activity with IC₅₀ values of 53 μM and 21 μM, respectively. The anti-influenza virus A (H1N1) activity and protein tyrosine phosphatase 1B (PTP1B) inhibitory activity of p-terphenyls are reported for the first time. Asperterphenyllin G exhibited cytotoxicity against nine cell lines with IC₅₀ values ranging from 0.4 to 1.7 μM. Asperterphenyllin C showed antimicrobial activity against Proteus species with a MIC value of 19 μg/mL.     

饲粮高钙对雏鸡锌利用的影响

试验采用含钙0.88％和1.78％的玉米—豆饼型基础饲粮(含锌29ppm,添加0.10和40ppm锌(ZnSO_4·7H_2O)。结果表明,随着饲粮锌水平的提高,雏鸡增重显著提高(P<0.01),这种效应随着雏鸡周龄的增长愈趋明显。饲粮高钙使雏鸡前期增重显著降低(P<0.01),后期效应愈趋缓解。血清碱性磷酸酶的活性随着饲粮锌水平的提高而显著提高(P<0.01),饲粮高钙使之显著降低(P<0.01)。饲粮加锌使血清白蛋白含量显著高于未加锌组(P<0.05),饲粮高钙使血清白蛋白含量显著降低(P<0.01),使血清球蛋白含量显著提高(P<0.01),而血清总蛋白含量不受饲粮钙水平显著影响(P>0.05)。肝脏(P<0.05)、肾脏(P<0.01)、胰脏(P<0.01)、胫骨(P<0.01)以及粪便排泄物(P<0.01)中锌含量随饲粮锌水平的提高而显著提高,肺脏锌含量没有明显变化(P>0.05)。饲粮高钙使肾脏(P<0.05)、肺脏(P<0.01)、胫骨(P<0.05)锌含量显著降低,使粪便排泄物中锌含量显著提高(P<0.05)。饲粮中含锌29ppm,不能满足雏鸡维持正常代谢和生长发育的营养需要,饲粮高钙时,饲粮总锌69ppm为宜。     

Genetic model analysis on seedling and maturity traits in wheat under rainfed conditions

An experiment was conducted to access the genetic variability among early vigour and quantitative traits under limited moisture in F₂ generation of a 5 × 5 diallel cross of bread wheat. The results indicated that there was significant genotypic variation among the genotypes. Additive dominance model revealed full fitness of the data for RL, DSW, FRW, DRW, spike length, and 1000-grain weight but was partially fit for SL, FSW, R/S, tillers per seedling, plant height, tillers per plant, spikelets per spike, and grain yield per plant. The partially adequate models for these plant characters might be due to the presence of non-allelic interaction, linkage, and non-independent distribution of the genes in the parents. Additive genes coupled with moderate to high narrow sense heritability were involved in the heritage of all the traits, which indicated a higher scope of selection in early generations.     

长白山林区主要可燃物类型地表可燃物载量分析

对长白山林区主要可燃物类型地表可燃物载量进行了对比分析和聚类分析。通过可燃物类型载量的对比分析,得出易燃的可燃物类型是云冷杉林(鱼鳞云杉103a)、落叶松林(115a)和云冷杉林(鱼鳞云杉80a),最不易燃的是岳桦林(142a)、白桦林(87a)和岳桦林(115a);释放能量最大的可燃物类型是落叶松林(115a),释放能量最小的可燃物类型是白桦林(87a)。通过各可燃物类型的1h时滞可燃物载量和地表总可燃物载量的聚类分析,可把13个可燃物类型化为6类。     

Barseem (Trifolium alexandrnum) protein concentrate in broiler rations

Animal protein in broiler rations was replaced with Barseem Protein Concentrate (BPC). The standard group having blood, meat and fish meal as sources of animal protein showed an average weight gain of 1655 g. Replacement of blood meal with BPC resulted in a slight decrease in the average weight gain (1541 g) of broilers. Average weight gain of broilers increased to 1775 g and 1671 g when fish or meat meal was replaced with BPC in rations. Complete replacement of animal protein with BPC adversely affected growth and average weight gain decreased to 1443 g. Supplementation with lysine or methionine when animal protein was replaced with BPC did not improve growth of the broilers.     

Effects of transition season management on soil N dynamics and system N balances in rice–wheat rotations of Nepal

In the low-input rice–wheat production systems of Nepal, the N nutrition of both crops is largely based on the supply from soil pools. Declining yield trends call for management interventions aiming at the avoidance of native soil N losses. A field study was conducted at two sites in the lowland and the upper mid-hills of Nepal with contrasting temperature regimes and durations of the dry-to-wet season transition period between the harvest of wheat and the transplanting of lowland rice. Technical options included the return of the straw of the preceding wheat crop, the cultivation of short-cycled crops during the transition season, and combinations of both. Dynamics of soil N_min, nitrate leaching, nitrous oxide emissions, and crop N uptake were studied throughout the year between 2004 and 2005 and partial N balances of the cropping systems were established. In the traditional system (bare fallow between wheat and rice) a large accumulation of soil nitrate N and its subsequent disappearance upon soil saturation occurred during the transition season. This nitrate loss was associated with nitrate leaching (6.3 and 12.8 kg ha⁻¹ at the low and high altitude sites, respectively) and peaks of nitrous oxide emissions (120 and 480 mg m⁻² h⁻¹ at the low and high altitude sites, respectively). Incorporation of wheat straw at 3 Mg ha⁻¹ and/or cultivation of a nitrate catch crop during the transition season significantly reduced the build up of soil nitrate and subsequent N losses at the low altitude site. At the high altitude site, cumulative grain yields increased from 2.35 Mg ha⁻¹ with bare fallow during the transition season to 3.44 Mg ha⁻¹ when wheat straw was incorporated. At the low altitude site, the cumulative yield significantly increased from 2.85 Mg ha⁻¹ (bare fallow) to between 3.63 and 6.63 Mg ha⁻¹, depending on the transition season option applied. Irrespective of the site and the land use option applied during the transition season, systems N balances remained largely negative, ranging from −37 to −84 kg N ha⁻¹. We conclude that despite reduced N losses and increased grain yields the proposed options need to be complemented with additional N inputs to sustain long-term productivity.