Global metabolomic analysis of blood from mice infected with Brucella abortus

To better understanding Brucella abortus infection, serum metabolites of B. abortus-infected and -uninfected mice were analyzed and twenty-one metabolites were tentatively identified at 3 and 14 days post-infection (d.p.i.). Level of most lysophosphatidylcholines (LPCs) was found to increase in infected mice at 3 d.p.i., while it was decreased at 14 d.p.i. as compared to uninfected mice. In contrast, acylcarnitines were initially reduced at 3 d.p.i then elevated after two-weeks of infection, while hydroxysanthine was increased at 14 d.p.i. in infected mice. Our findings suggest that the significant changes in LPCs and other identified metabolites may serve as potential biomarkers in acute phase of B. abortus infection.     

紫甜玉米产量及其构成因素和品质性状的杂种优势和配合力分析

【目的】对20个紫甜玉米自交系与2个测试种进行产量及其构成因素和品质性状的杂种优势和配合力分析,为高效创制高产甜玉米自交系提供材料基础和理论依据。【方法】将20个紫甜玉米自交系（TD01~TD20）与2个测试种[黄色甜玉米自交系（TI）和白色甜玉米自交系（T2）]进行杂交组配,采用完全随机组设计对获得的40个杂交组合（TH01~TH40）进行田间试验,以SW1011和Fancy 111为对照品种。测定亲本及其杂交组合的产量及其构成因素和品质性状。利用Line×Tester模型在AGD-R软件中进行中亲优势度（Hm）、杂种优势度（Hb）和一般配合力（GCA）分析。【结果】紫色种皮由父本遗传,在40个杂交组合中占优势,所有测定的性状表现为中亲优势和杂种优势。大多数亲本系鲜穗收获期的Hm、Hb和GCA表现为负值,说明这些亲本系具有组配早熟杂交种的潜力。除收获期和穗粗外,其余调查性状表现出多个显性效应,证明了非加性遗传效应的重要性。具有较高GCA的杂交组合为TH05（T1×TD05）、TH31（T2×TD11）、TH20（T1×TD20）、TH33（T2×TD13）、TH34（T2×TD14）、TH16（T1×TD16）、TH08（T1×TD08）和TH25（T2×TD05）。【结论】紫色甜玉米与黄色甜玉米自交系或白色甜玉米自交系杂交,紫色性状具有显性效应,筛选出的8个品质优良杂交种及其亲本可作为培育越南商品化紫甜玉米品种的亲本材料。     

Phosphorus sorption in soils of the Mekong Delta (Vietnam) as described by the binary Langmuir equation

Phosphate adsorption isotherms were determined for 20, mostly very acidic, soils from the Mekong Delta. The experimental data were well described by a binary Langmuir equation which considers two groups of sorption sites that differ in their P bonding energies. The maximum P-sorption capacities of these sites were related to the soil properties by simple linear correlation and by stepwise multiple regression. Results suggest that high energy sites are on Al-oxihydroxides or small Al-substituted Fe-oxides and, to a lesser extent, on poorly ordered Fe-oxihydroxides. On the other hand, the P-sorption capacity of low energy sites is mainly related to clay content, and it increases as pH decreases. These sites are also positively correlated with organic carbon and poorly crystalline Fe-oxihydroxides. However, as these two variables are closely correlated with each other, organic matter is likely to be considered as an indirect factor of P fixation through its association with Fe-oxihydroxides and not as an important source of P-sorption sites. The maximum sorption capacity, i.e. the sum of sorption capacities of the two groups of sites, is well described (r²= 0.88) by an equation that takes into account the four variables identified above: Al-bearing oxihydroxides, poorly ordered Fe-oxihydroxides, clay content and pH. Grouping the soils according to the orders of Soil Taxonomy, the P-sorption capacity increases in the following sequence: ultisols < entisols < inceptisols. A P concentration often considered adequate for plant nutrition is 0.2 mg P 1^?1 solution, and only the high energy sites are involved in sorption at that concentration. Thus an equation including only Al- and Fe-oxihydroxides could be used to fix P norms in these soils.     

特色紫甜玉米自交系选育高营养水果型杂交玉米的应用研究

【目的】通过紫色糯玉米（花青素型）与白色甜玉米（超甜糯型）杂交,选育出营养丰富的水果型玉米,以满足越南乃至世界对高营养水果型玉米的市场需求,也为水果型玉米的杂交选育提供参考。【方法】将4个紫色糯玉米品系（♀）与白色甜玉米（♂）进行杂交后再回交,通过形态标记（籽粒皱缩且颜色为深紫色）从BC2F1代中共筛选出20个品系,再经5代连续自交获得80个自交系（UV01~UV80）,从中选择20个优良自交系。利用Line×Tester模型将20个优良自交系与2个测试种［黄色甜玉米自交系SW1（TI）和白色甜玉米自交系D181（T2）］进行测配,获得40个杂交组合（TH01~TH40）,通过随机区组设计在越南河内田间开展种植试验,以SW1011和Fancy111为对照品种。【结果】 TH08、TH17、TH18、TH27、TH31和TH35等6个杂交组合的平均产量较高,为13.4~14.4 t/ha,与对照品种SW1011无显著差异（P>0.05）,说明这些杂交组合具有较高的商业潜力; UV03、UV07、UV08、UV10、UV12、UV16、UV18、UV42、UV71等9个品系的锤度>16.0%、果皮薄<60.0 μm、花青素含量>100.0 mg/100 g,属于超甜紫甜玉米品系。UV10、UV24、UV40、UV46和UV71等5个品系在商品产量方面具有较高的一般配合力（GCA）,UV12和UV16品系在甜度指数方面具有较高的GCA,UV35、UV36、UV38、UV46和UV73等5个品系在花青素含量方面具有较高的GCA。【结论】 UV10和UV12在产量和品质方面均具有较高的GCA,为2个营养丰富的水果型超甜紫甜玉米品系,可在越南及其他适用地区推广种植。