菌藻共生系统在生猪养殖污水处理中的应用及其互作机制的研究进展

生猪养殖污水中污染物负荷高,处理难度大,对环境造成潜在风险.菌藻共生系统是微藻与细菌的共生系统,目前已在国内外开展了广泛研究,可高效去除污水中的氮、磷等污染物,具有较好的开发应用前景.本文就近年来菌藻共生系统对生猪养殖污水中氮、磷和重金属等的处理效果展开综述,深入介绍藻菌间在氮磷营养元素利用等方面的互作机制,并对可能影...     

白术白绢病的防治研究

白绢病(Sclerotium rolfsii Sacc。)是中药白术上的一种严重病害。白术主产区常年损失颇为严重。杭州地区白术白绢病从5月上旬开始发生,一直延续到9月下旬,6～8月较重。被害白术,药用根茎腐烂,植株凋萎枯死。在浙江除白术受害外,还发现有12个科25种药用植物被此病为害。其中菊芋、玄参、乌头和黄芪受害最重。遗留在土中的菌核、种用病术、带菌肥料是此病的主要初次侵染来源。高温多湿有利白绢病的发生;施用牛粪、垃圾有加重发病的趋势;低坡地比高坡地、水田比旱地发病要重;连作、株行距小的病情重。用1%石灰液浸菌核2小时及大田每株用石灰粉2.5克,拌接菌核土壤试验,效果显著;0.5%硫酸铜液浸菌核和白术田浇治(100毫升/株)效果也较好。     

韭菜中毒死蜱残留量与高光谱特征参数的相关性建模

本研究目的在于分析农药残留量(pesticide residue,PR)与高光谱中响应特征参数之间的关系,并利用筛选的光谱特征参数建立反演毒死蜱残留量的有效模型。首先采用ASD Fieldspec高光谱仪测得韭菜样本的光谱,通过气相色谱-质谱联用(GC-MS)法测得毒死蜱残留量(PR)值;分析样本光谱反射率值及其一阶微分值与毒死蜱残留量的相关性,计算33个高光谱特征参数与毒死蜱残留量的相关性;根据相关系数高低选择敏感的光谱特征参数;最后采用最佳相关系数下的光谱特征参数对毒死蜱残留量进行建模反演。相关性分析结果显示:近红外波段789~867 nm范围内一阶微分光谱值与PR值呈正相关,1 860 nm处一阶微分光谱值(first-order differential 1 860 nm,FD1860)与PR值紧密相关;在33个高光谱特征参数中,近红外一阶微分总和(the sum of first-order differential near infrared,SDnir)与PR值呈良好的正相关关系。基于此,文章以供试样本的FD1860和SDnir观测值为自变量,分别建立了3个预测毒死蜱残留量的模型,即线性、二次多项式及指数模型,并采用交叉验证测试方法检验了模型的合理性。对实验所得决定系数R2和预测均方根误差(RMSE)的评价结果表明,以SDnir为自变量构建的模型稳定性强,其二次多项式模型是最佳反演毒死蜱残留量的有效模型。因此,样本的高光谱特征参数SDnir的变化幅度直接反映了韭菜样本中毒死蜱残留量的变化,表明运用蔬菜的高光谱特征参数反演蔬菜中农药残留量的方法是可行的。     

南方红壤侵蚀区农业生态系统的能值分析——以福建长汀县为例

应用能值分析的理论与方法,对福建省长汀县农业生态系统的能值流进行了定量分析.根据长汀县农业生态系统的情况选择了能值投资率、净能值产出率、环境承载力、可持续发展指数、系统生产优势度及系统稳定性指数等10个指标进行分析,其中净能值产出率为11.40、能值投资率为1.91、环境承栽力为2.21、可持续发展指数为19.10、系统生产优势度为0.53以及系统稳定性指数为0.90.结果表明:该县处于传统农业向现代农业转变的过渡阶段,系统能值投入水平和转化效率较低.为了促进长汀县农业的可持续发展,应调整能值投入结构,逐步提高石化能源的利用效率,并增大农业科技的研究和推广力度.增加农业生态系统的产出能力.     

冷却干燥通风过程中粮仓内热湿耦合传递的数值模拟

基于多孔介质传热传质的理论,建立了一种冷却干燥通风过程中粮仓内热湿耦合传递的数学模型。借助数值模拟的方法,对冷却干燥通风过程中粮仓内温度和水分的变化进行了模拟研究,得到了冷却干燥通风过程中粮堆内部热量传递和水分迁移的基本规律。     

Detection ofBabesia bovis using a DIG-labeled DNA probe

Tropical Animal Health and Production - A plasmid DNA containing the insertedBabesia bovis cDNA clone designated c5lA was used to prepare a DNA probe forB. bovis. The purified 0·6 kb specific...     

Anemia of male rearing calves. 2. Duration of anemia

From 203 male rearing calves in a longitudinal study during the first rearing period in a rearing farm the time could be determined in which the hemoglobin quota, the hematocrit resp. the average corpuscular hemoglobin concentration were lower than 10,5 g/dl, 33% resp. 30.5 g Hb/dl erythrocytes. The average duration of anaemia was 45, 29.5 resp. 44 days of the total of 56 keeping days in this rearing range (80.4%, 52.7% resp. 78.6% of the keeping period). During this rearing period 89.2%, 71.4% resp. 90.6% of all animals were anaemic for a shorter or longer time. With 29.8%, 26.2% resp. 29.9% of the anaemic calves the anaemic phase exceeded 56 days.     

A joint analysis to identify loci underlying variation in nematode resistance in three European sheep populations

Gastrointestinal nematode infections are one of the main health/economic issues in sheep industries, worldwide. Indicator traits for resistance such as faecal egg count (FEC) are commonly used in genomic studies; however, published results are inconsistent among breeds. Meta (or joint)‐analysis is a tool for aggregating information from multiple independent studies. The aim of this study was to identify loci underlying variation in FEC, as an indicator of nematode resistance, in a joint analysis using data from three populations (Scottish Blackface, Sarda × Lacaune and Martinik Black‐Belly × Romane), genotyped with the ovine 50k SNP chip. The trait analysed was the average animal effect for Strongyles and Nematodirus FEC data. Analyses were performed with regional heritability mapping (RHM), fitting polygenic effects with either the whole genomic relationship matrix or matrices excluding the chromosome being interrogated. Across‐population genomic covariances were set to zero. After quality control, 4123 animals and 38 991 SNPs were available for the analysis. RHM identified genome‐wide significant regions on OAR4, 12, 14, 19 and 20, with the latter being the most significant. The OAR20 region is close to the major histocompatibility complex, which has often been proposed as a functional candidate for nematode resistance. This region was significant only in the Sarda × Lacaune population. Several other regions, on OAR1, 3, 4, 5, 7, 12, 19, 20 and 24, were significant at the suggestive level.     

七种培养料对糙皮侧耳熟料栽培的影响

研究了棉籽壳、玉米芯、大豆秸、棉柴屑、金针菇(Flammulina velutipes)菌糠、废棉、木屑等7种培养料对糙皮侧耳(Pleurotus ostreatus)熟料栽培的影响。结果表明:大豆秸、玉米芯、废棉吸水能力和持水能力都比较强;糙皮侧耳栽培期间,7种培养料含水量和pH值呈现相似的变化规律,除灭菌后到菌丝满袋期培养料含水量和pH值上升外,其它时期均下降;糙皮侧耳菌丝在大豆秸上生长最快、长势最好,在木屑和玉米芯上生长最慢、长势最差;在废棉、大豆秸上产量较高,在木屑上产量最低。     

乙烯利对菠萝叶片氨基酸代谢的影响

用植物激素乙烯利（Ｃ＿２Ｈ＿６Ｏ＿３ＣｌＰＯ＿３）对菠萝进行催花。在灌注乙烯利前、后测定叶片中游离氨基酸的变化并与未催花的对照株比较，植株在形成花芽和幼果期叶片中大多数游离氨基酸含量下降。尤其是组氨酸、精氨酸、丝氨酸、苏氨酸等变化明显，这可能是乙烯对“成花基因”调控直接起作用。也可能在乙烯作用下叶片提供给花芽形成所需特异蛋白质促使基因得以调控表达。本研究为进一步阐明菠萝花芽分化的实质提供了生物化学方面对比性背景资料。