A bayesian model for the analysis of lactation curves of dairy goats

This article aims to determine the effect of certain covariates, such as season of kidding, parity, and time of kidding on the characteristics of the lactation curve of Saanen dairy goats. Characteristics investigated are peak milk yield, time of peak milk yield, total milk production, persistency, and the relationship between fat and protein in milk composition, as well as between lactation curves of the same animal in successive years. The analysis is carried out using a hierarchical Bayesian approach, together with Wood’s model, to model lactation. Posterior distributions of quantities of interest are obtained by means of the Markov chain Monte Carlo (MCMC) methods. These clearly illustrate the significant effect of especially parity, but also season and time of kidding on the characteristics of the lactation curve. Total and peak milk yield increase with increasing parity up to about the third or fourth parity, while peak yield is later for first than for later parities. The analysis also enables estimation of lactation characteristics of untested animals, prediction of future characteristics and identification of exceptional animals.     

Recovery of cover-crop-N in the soil-plant system in the Guinea savannah zone of Ghana

In order to understand the efficiency of residue-N use and to estimate the minimum input required to obtain a reasonable level of crop response, it is important to quantify the fate of the applied organic-N. The recovery of N from ¹⁵N-labelled Crotalaria juncea was followed in the soil and the succeeding maize crop. Apparent N recovery (ANR) by maize from unlabelled Crotalaria juncea, Crotalaria retusa, Calopogonium mucunoides, Mucuna pruriens and mineral fertilizer at three locations were also evaluated. The maize crop recovered 4.7% and 7.3% of the ¹⁵N-labelled C. juncea-N at 42 days after sowing (DAS) and at final harvest, respectively. The corresponding ¹⁵N recovery from the soil was 92.4% and 58.5%. The highest mean ANR of 57.4% was with mineral fertilizer, whereas the mean ANR of 14.3% from C. retusa was the lowest. A large pool substitution and added-N interaction effect was observed when comparing N recovery from the labelled and unlabelled C. juncea. The amount of residue-N accounted for by the isotope dilution method at 42 DAS was 97.1% and at final harvest 65.8%. The large residue-N recovery in the soil organic-N pool explains the residual effect usually observed with organic residue application.     

Nitrogen and carbon mineralisation of leather meal in soil as affected by particle size of fertiliser and microbiological activity of soil

Carbon and nitrogen mineralisation of leather meal fertilisers were studied in two soils characterised by different respiration activity. Both C and N mineralisation were highest in the most active soil, and when leather meal was added as a powder rather than as 2- to 4- and 4- to 6-mm particles. Fast and slow soluble N pools were determined after extraction with cold water and with hot buffer, respectively. The N remaining after the second extraction with hot buffer was named slow-release N. The percentage of slow-release N rose as the size of the applied leather meal particles increased, whereas fast soluble N was highest in the coarsest (4-6 mm) fertiliser.     

不同比例尺DEM提取地面坡度的精度研究——以在黄土丘陵沟壑区的试验为例

以陕北绥德县韭园沟流域为试验样区 ,采用高精度 1∶ 1万 DEM所提取的坡度为准值 ,应用多层面复合分析和比较分析的方法 ,研究该地区 1∶ 5万 DEM提取地面坡度的误差特征与纠正方法。试验结果显示 ,所获得的不同空间尺度下 DEM所提取坡度值的转换图谱 ,可对 1∶ 5万 DEM计算的地面坡度统计值进行有效修正。该成果对于 DEM数据在水土保持领域若干应用标准的制定 ,提供了重要的理论依据与技术路线     

Effect of bensulfuron-methyl (a sulfonylurea herbicide) on the soil bacterial community of a paddy soil microcosm

The effect of bensulfuron-methyl (BSM) on a soil microbial community in a model paddy microcosm was studied. Total bacterial numbers in the overlying water and surface soil were monitored for 2 months after the application of BSM at the field rate and a ten-fold field rate. Pentachlorophenol (PCP) was used for comparison. Neither chemical affected the total bacterial numbers remarkably, either in the overlying water or in the surface soil. In contrast, the nitrification potential was significantly suppressed by the BSM application. The bacterial community structure, as evaluated by the denaturing gradient gel electrophoresis (DGGE) of PCR amplification products from bacterial 16S rDNA, was unaffected by the BSM treatments over 8 weeks in the surface soil, compared with the control (no pesticide). In contrast, the surface soil exposed to PCP at a ten-fold field rate showed different patterns from the controls at 4 weeks and 8 weeks after application. The DGGE patterns of the overlying water were much more variable than those of the surface soil in any treatments. Cluster analysis showed that the BSM plots were classified within the same group as the control at 1 week after application and that the BSM and PCP plots from 2 weeks onward after application were grouped differently from the control. Of 22 clones excised from the DGGE gels, 20 clones belonged to the Proteobacteria and two belonged to the Verrucomicrobia. It was considered that the impact of BSM on the overall microbial community (total numbers, community structure of soil) was negligible, although BSM had an impact on some specific functions of the soil microbial community (nitrification) and a part of the community (overlying water).     

冬播麦区Glu-1和Glu-3位点变异及1B/1R易位与小麦加工品质性状的关系

 贮藏蛋白组成是决定小麦加工品质的重要因素。本文调查了我国冬播麦区251份主栽品种和高代品系的高分子量麦谷蛋白亚基（HMW-GS）、低分子量麦谷蛋白亚基（LMW-GS）和1B/1R易位的分布状况，研究了它们与加工品质性状的关系。结果表明，品质较差的HMW-GS N、7+9、2+12和LMW-GS Glu-A3a与Glu-B3j（1B/1R易位）在冬播麦区分布较广，频率分别为39.4%、45.0%、59.8%、37.1%和44.6%。HMW-GS和LMW-GS等位变异对籽粒蛋白质含量影响较小，对SDS沉降值、和面时间与耐揉性的加性和互作效应达1%的显著水平。按位点对加工品质性状的贡献大小，Glu-D1>Glu-B3>Glu-B1>Glu-A3>Glu-A1；就单个亚基而言，Glu-A1位点，1>2*>N；Glu-B1位点，7+8>14+15>7+9；Glu-D1位点，5+10>4+12>2+12；Glu-A3位点，Glu-A3d>Glu-A3a>Glu-A3c>Glu-A3e，Glu-B3位点； Glu-B3d>Glu-B3b>Glu-B3f >Glu-B3j。1B/1R易位对SDS沉降值、和面时间和耐揉性等加工品质性状有显著负面效应。通过选择优质高低分子量麦谷蛋白亚基和淘汰1B/1R易位系，将有助于提高我国小麦的面筋质量。     

葡萄利用结果枝副梢二次结果栽培试验

摘要：在桂林葡萄产区开展利用结果枝副梢促花二次结果的栽培试验,总结在新梢生长期喷多效唑（或矮壮素）、对新梢重度修剪促进冬芽提早萌发是整齐促放葡萄二茬果的关键技术,观测了二茬果果品品质和效益,提出了生产二茬果注意的技术问题。     

大豆抗菌核病的全基因组关联研究

找到大豆与抗菌核病强关联的候选位点或候选基因,为抗病基因克隆和抗病分子标记开发提供借鉴,服务大豆抗菌核病育种。对126个加拿大大豆品种的基因组DNA用ApekⅠ酶消化后Illumina Hiseq2000平台测序进行基因分型,供试的126个材料用棉垫接种核盘菌菌丝体进行表型鉴定。采用Structure 2.3.4、SPSS 20.0、TASSEL 5.0和PLINKv 1.07软件分别模拟群体遗传结构、二元主成分分析、邻接法聚类,进行SNP-phenotype和Haplotype-phenotype的关联分析(只考虑加性效应)。最小等位基因频率0.01过滤,得到30 125个SNPs。主成分及群体结构聚类结果中度一致,将126个供试材料划分为2个组群,Kappa聚类一致度检验K=0.44。邻接法(The neighbor-joining algorithm,NJ)聚为3个组群。α≤0.05时,在单个SNP-phenotype的关联研究中,最强关联在3号染色体物理位置34387780、34387823和34387841处(P值都为8.669E-7),可分别解释表型变异的17.80%,其次在20,1,4,17号染色体上。Haplotype-phenotype的关联分析中,最强关联在17号染色体物理位置5575883/5647814/5648648/5734897处(P值为1.038E-6),可解释表型变异的17.56%。200 kb范围内,3号染色体上的候选基因有Glma.03g129100、Glma.03g129200、Glma.03g129300、Glma.03g129500、Glma.03g129800、Glma.03g129900。17号染色体上为Glma.17g071300、Glma.17g072200、Glma.17g073300。     

中国沙塘鳢属鱼类的整理和一新种的叙述

本文应用沙塘鳢属鱼类的外形特征、头部感觉管孔的有无及感觉乳突之排列方式作为分类依据，对采自中国各河川800余尾沙塘鳢属鱼类进行较全面．系统的研究，还对比产于日本和韩国的种类，解决了中国沙塘鳢属长期混淆不清的分类问题．中国沙塘鳢属鱼类有4种(其中有一新种)，即河川沙塘鳢O．optamophila(Gǖnther)，海丰沙塘鳢O．haifengensis Chen.，鸭绿沙塘鳢(新种)O．yaluensis Wu，Wu et Xie sp．nov．和暗色沙塘鳢0．obseura(Temm.et Schl.)