饲用玉米连作土壤可培养细菌多样性与肥效菌株监测

为深入了解饲用玉米连作对土壤微生物多样性的影响,对甘肃区采集的连续7年种植玉米土壤中可培养细菌的多样性和促生细菌资源进行全面地分析和挖掘。分别利用富营养(NA)和选择性(Ashby)培养基进行可培养细菌的分离,对获得菌株进行16S rRNA基因测序和比对分析,评价其产植物生长素(IAA)、溶磷、固氮等能力。自不同年份土壤中共分离得到各类细菌224株。菌株功能评价结果表明,34株具有产IAA的能力,25株具溶解有机磷的能力,19株具溶解无机磷的能力,27株具有较高的固氮酶活性,有5株可同时具有产IAA和溶磷的功能。可培养细菌分离信息分析结果表明,种植玉米土壤的细菌及肥效菌株的丰富度及多样性随着连作年限的增加呈逐渐上升趋势,优势菌属均为Pseudomonas,广泛分布于各年份的土壤中,且表现出优秀的产IAA、溶磷及固氮的能力。研究表明,玉米7年连作可明显影响土壤菌群结构,土壤中蕴藏着丰富的有益功能细菌资源。分离的功能菌株为研制适用于甘肃玉米绿色生产的微生物肥料提供信息与优良菌种支撑。     

Phaseolus vulgaris L. Leaves Increase Short-Chain Fatty Acid (SCFA) Production,Ameliorating Early Metabolic Alterations

Plant Foods for Human Nutrition - High-fat/high-fructose diets promote early metabolic disorders in weight and lipid and glucose metabolism. Bioactive compounds such as polyphenols and fiber...     

Starch Digestion in Infants: An Update of Available In Vitro Methods—A Mini Review

Plant Foods for Human Nutrition - Complementary feeding starts at around six months of age because neither breast milk nor formula assure the proper nutrition of infants. Therefore, along...     

中外高速铁路发展与安全防灾体系研究

针对近年来我国高速铁路运营方面事故与故障多发、频发的现状,从分析我国及日本、法国、德国等发达国家高速铁路发展状况入手,对四国高速铁路安全防灾体系特征进行了概括分析,提出了进一步加强我国高速铁路安全防灾体系建设的建议,为高速铁路安全管理和运营提供参考。     

水分胁迫下菊苣航天诱变新品系保护酶活性变化

[目的]该研究旨在了解航天诱变对菊苣不同品系保护酶活性的影响,为南方喀斯特地区筛选耐旱植物提供科学依据。[方法]以‘实践八号’育种卫星搭载选育出的菊苣新品系和目前主推的菊苣品种为研究对象,对SOD活性、POD活性、CAT活性以及丙二醛含量进行测定。[结果]随着水分胁迫时间的增加,PA-82、普那菊苣和PA-43的丙二醛含量逐渐升高,在处理12 d时,分别上升了0.575、0.72和0.844μmol/g;SOD、POD和CAT活性迅速升高,在处理9 d时,PA-82、普那菊苣和PA-43的SOD分别上升了878.9、809.2和711.1U/g,上升幅度为139.1%、136.7%和121.1%;POD分别上升了4 397、3 754和2 767 U/（g·min）,上升幅度为265.84%、257.65%和204.06%;CAT分别上升了402.1、277.1和170.9 KU/L,上升幅度为73.08%、39.69%和26.20%;之后3种保护酶均出现大幅度下降,12 d时,PA-82、普那菊苣和PA-43的SOD分别下降1 206.5、1 144.7和1 108.6 U/g,POD分别下降3 145、2 876和2 753 U/（g·min）,CAT分别下降587.2、698.1和584.1 KU/L。[结论]经综合评价,3种菊苣的抗旱能力为PA-82〉普那菊苣〉PA-43。     

Study on Hsp90 Expression in Different Tissues and Its Antibody in Serum of Chickens Infected with Marek’s Diseases

To investigate the dynamic change of heat shock protein 90 （Hsp90） in the genesis and development of tumor, we successfully established tumor animal model using Marek’s disease and then determined the location of Hsp90 in the tumor tissue using immunohistochemistry method, the antibody titer level of Hsp90 in the serum and the expression level in the tissue using enzyme-linked immunosorbent assay （ELISA） method. Our result showed that Hsp90 location in the tumor tissue was signiifcantly associated with the tumor cell and most in the cytoplasm of the tumor cell, and Hsp90 expression level in the tissue and the antibody titer level in the serum was most signiifcantly increased with the development of tumor. This is the ifrst report to show the presence of Hsp90 in tumor tissues induced by the Marek’s disease, with its expression correlated to the tumoral grading. These data may also be valuable for developing new molecular anti-cancer therapies.     

Carbon and Nitrogen Contents in Typical Plants and Soil Profiles in Yanqi Basin of Northwest China

Carbon and nitrogen are the most important elements in the terrestrial ecosystem. Studying carbon and nitrogen distributions in plant and soil is important for our understanding of the ecosystem dynamics and carbon cycle on arid lands. A study was conducted in a typical arid area, the Yanqi Basin, Northwest China. Carbon and nitrogen distributions in plant tissues and soil profiles were determined at 21 sites with typical native plants and crops. Our results indicated that carbon content was similar between crops and native plants, and the average carbon contents in aboveground （42.4%） and belowground （42.8%） tissues were almost the same. Average nitrogen contents in crops were nearly the same （~0.7%） in aboveground and belowground tissues whereas mean nitrogen content was approximately 100% higher in aboveground （2.2%） than in belowground （1.2%） tissues for native species. Soil organic carbon （SOC） and total nitrogen （TN） in cropland （9.4 and 0.9 g kg^-1） were significantly higher than those in native land （6.2 and 0.7 g kg^-1）. Multiple regression analyses indicated that carbon content in belowground tissue and nitrogen content in aboveground tissue were key factors connecting plant and soil in native land. However, there was no significant relationship for carbon or nitrogen between soil and crop, which might reflect human disturbance, such as plowing and applications of various organic materials.     

Does Biochar Addition Influence the Change Points of Soil Phosphorus Leaching?

Phosphorus change point indicating the threshold related to P leaching, largely depends on soil properties. Increasing data have shown that biochar addition can improve soil retention capacity of ions. However, we have known little about weather biochar amendment influence the change point of P leaching. In this study, two soils added with 0, 5, 10, 20, and 50 g biochar kg-1 were incubated at 25℃ for 14 d following adjusting the soil moisture to 50% water-holding capacity （WHC）. The soils with different available P values were then obtained by adding a series of KH2PO4 solution （ranging from 0 to 600 mg P kg-1 soil）, and subjecting to three cycles of drying and rewetting. The results showed that biochar addition significantly lifted the P change points in the tested soils, together with changes in soil pH, organic C, Olen-P and CaC12-P but little on exchangeable Ca and Mg, oxalate-extractable Fe and Al. The Olsen-P at the change points ranged from 48.65 to 185.07 mg kg-1 in the alluvial soil and 71.25 to 98.65 mg kg^-1 in the red soil, corresponding to CaCl2-P of 0.31-6.49 and 0.18-0.45 mg L~, respectively. The change points of the alluvial soil were readily changed by adding biochar compared with that of the red soil. The enhancement of change points was likely to be explained as the improvement of phosphate retention ability in the biochar-added soils.     

贵州不同栽培茶树品种红茶适制性分析

以贵州栽培茶树品种福鼎大白茶、黔湄601、黔湄502、黔湄809、黔湄419、湄潭苔茶的一芽一叶茶青为原料,分别制成蒸青样和红茶样,采用理化分析结合感官审评的方法分析茶样生化成分及感官质量.试验结果表明,酚氨比最大的为黔湄419茶树品种;叶绿素a/叶绿素b值最大的是黔湄419茶树品种;茶红素/茶黄素值最大的是黔湄809茶树品种.6个茶树品种的红茶样感官审评结果均较好.     

长白落叶松S_(1-1)换床苗配方施肥技术研究

以长白落叶松S1-1苗木为对象,利用正交试验方法研究氮、磷、钾肥对苗木生长量和叶绿素含量的影响,结果表明:影响苗木生长的各肥料因子表现为尿素过磷酸钙≥硫酸钾,其中,尿素对苗高、地径及叶绿素含量的影响差异显著,为影响苗木各项指标的主导因子;培育换床苗的最佳施肥量为尿素55 g·m-2、过磷酸钙200 g·m2或150 g·m-2、硫酸钾60 g·m-2或20 g·m-2。