日本结缕草ZjNAC1的克隆、转录激活活性、亚细胞定位及表达分析

采用RACE技术从日本结缕草中克隆得到ZjNAC1转录因子(GenBank No. MH428376),其开放阅读框为945bp,编码314个氨基酸。ZjNAC1编码的蛋白在N端有1个典型的NAM保守结构域,属于NAC转录因子家族。通过染色体步移的方法,获得ZjNAC1基因ATG上游1635bp序列,分析发现其包含响应脱落酸(ABA)、茉莉酸甲酯(MeJA)及逆境胁迫的作用元件。构建pGBKT7-ZjNAC1载体,转化Y2HGold酵母感受态细胞,发现ZjNAC1具有转录激活活性。农杆菌介导的35S-ZjNAC1-YFP载体注射本生烟草叶片瞬时表达结果显示,ZjNAC1定位于细胞核。实时荧光定量结果表明,ZjNAC1在日本结缕草根中表达量最高;此外,ZjNAC1的表达受10μmol/L MeJA和20%PEG4000处理的诱导,但受200μmol/L乙烯(ET)、10μmol/L ABA和300mmol/L NaCl处理的抑制。     

鹿源狂犬病野毒8202株基因型的研究

为了从基因水平确定鹿源狂犬病野毒8202株与其它狂犬病病毒的进化关系,应用RT-半嵌套式PCR技术,利用3条引物对病毒的核蛋白基因进行扩增、克隆及序列测定,并与已发表的狂犬病病毒株3aG、PV、CVS、HEP-Flury、RC-HL、Nishigahara、SADB19的核蛋白基因进行了比较分析。结果表明,8202株与其它7个病毒株均来源于同一个进化枝,属于基因Ⅰ型。     

青海黄牛血清运铁蛋白多态性研究

采用聚丙烯酰胺凝胶电泳法对１００头青海黄牛的血清运铁蛋白多态性进行了研究。结果发现：青海黄牛血清运铁蛋白位点存在ＴＦ￣Ａ，ＴＦ￣Ｂ，ＴＦ￣Ｄ１，ＴＦ￣Ｄ２，ＴＦ￣Ｆ，ＴＦ￣Ｅ６个等位基因，总共构成１３个基因型。与国内１２个品种黄牛的遗传距离和聚类分析表明，青海黄牛与蒙古牛的亲缘关系最近（Ｄｍ＝０．１１７８）。     

苇状羊茅EST-SSR标记在草甸羊茅和多年生黑麦草的通用分析

草甸羊茅(Festuca pratensis Huds)和多年生黑麦草(Lolium perenne Lam)均是禾本科、多年生草本植物,是优良的牧草和草坪草.本研究采用40对苇状羊茅(Festuca arundinacea Schred)的表达序列标签-简单序列重复(Expressed sequence tags-s...     

高寒地区苦荞农艺性状及生产性能评价

为探索不同地区苦荞在高寒地区的农艺性状及生产性能,采用多重比较及聚类分析法分析了7个地区13种苦荞的农艺性状及生产性能。结果表明不同地区苦荞的农艺性状及生产性能差异显著(P0.05),云苦荞2号和晋苦荞2号的农艺性状及生产性能优于其他品种;聚类分析将13个荞麦样品分成2组,在一定程度上体现了荞麦资源的道地性特征,反映了不同苦荞品种的农艺性状及生产性能与亲缘关系之间有一定的联系。     

Microsoft Excel sensitivity analysis for linear and stochastic program feed formulation

Sensitivity analysis is a part of mathematical programming solutions and is used in making nutritional and economic decisions for a given feed formulation problem. The terms shadow price and reduced cost are familiar linear program (LP) terms to feed formulators. Because of the nonlinear nature of stochastic programming (SP), different methods and terminology are used to define shadow prices and reduced costs. The Lagrange multiplier is used instead of shadow price to describe marginal value of nutrients. Reduced gradient is used instead of reduced cost to describe the price at which ingredients not used in the formulation would be included in the solution. A spreadsheet feed problem was set up with 11 ingredients and 11 constraints. The LP and SP solutions were determined using the Excel Solver algorithm. Two problems compared LP and SP solutions at 50 and 69% probabilities for the protein constraint. All other constraints were held at a 50% probability. Results for the 50% probability comparison showed that the feed formulations, as expected, were the same for both LP and SP. Wheat was not included in the solution. The LP reduced cost and the SP reduced gradient for unused wheat were equivalent. The LP shadow prices and the SP Lagrange multipliers were equivalent. Results for the 69% probability problem showed a difference in the formulated rations. The LP reduced cost was $34.25 and the SP reduced cost was $34.52, showing the respective amounts that the cost of wheat would have to be reduced to be included in the solution. The shadow price and the Lagrange multiplier were $2.73 and $2.71, respectively, for the amount of increase in diet cost that could be expected by a unit of change in the protein requirement. Some differences in precision were noted with the results. A caveat is that, because of nonlinearity, sensitivity analysis for SP is valid only for the single point of the optimal solution.     

Do labour productivity and preferences about work load distribution affect reproduction management and performance in pig farms

Increases in labour productivity are essential factors, as well as technical effectiveness, for the competitiveness of pig farming. However, the preferences of farmers for controlled (i.e. limited) daily working hours or available days for vacation also increase. The objective of this study was to explore how these preferences about work might be associated to specific combinations of practices or affect performance. The study was carried out by direct investigation of the stockbreeders. Data analysis used factorial analysis to identify relationships between practices, labour productivity, sow productivity and work load distribution. Results showed independence between sow productivity and labour productivity. Three independent types of preferences about work load distribution were identified: the limitation of density of daily work, the avoidance of insemination activities during the weekend and the avoidance of farrowing supervision during the weekend. These preferences about work load distribution were mainly related to weaning, oestrus detection and insemination techniques. A relationship was also seen between farrowing and cross-fostering techniques, and labour and sow productivity. Results suggest that preferences about work load distribution influence the choice of reproduction practices without influencing performance. Finally, concerning the labour productivity, it was linked with some specific techniques at farrowing but the results also indicated that it was mainly related to the size of farrowing batches.     

不同放牧方式对山地草甸生产与生态功能及其权衡关系的影响

为实现喀纳斯景区山地草甸的可持续管理,本研究通过设置无牧对照(NG)、单牧马-轻牧区(HG)、牛马混牧-重牧区(MG)三种放牧方式,探求提高山地草甸生态系统多项生产和生态功能协同性的放牧方式。结果表明：不同放牧方式下山地草甸的生产功能放牧后较放牧前均有下降,生态功能中土壤N:P、植物N:P、凋落物N:P放牧后较放牧前均升高,其他生态功能降低,但HG的Shannon-Wiener指数在放牧后变化不大;NG的土壤呼吸速率和植被C:N升高。在山地草甸生态系统生产和生态功能的权衡关系中,权衡、协同和不相关关系同时存在,与牧草产量,草地质量指数相关的生产和生态功能存在协同关系;与植被平均高度、土壤呼吸速率、土壤碳储量相关的生产和生态功能存在权衡关系,其余指标为不相关关系。综上所述,最适放牧方式为HG,其协同关系最佳。     

Appraisal of the sustainability of dairy goat systems in Southern Spain according to their degree of intensification

This investigation aims to classify, describe and evaluate the sustainability of dairy goat production systems (GPS) in South Spain Sierra de Cadiz. The research took place throughout 25 goat farms during the 2001–2002 campaigns, with the method posed by Masera et al. (1999) [Masera, O., Astier, M., S., López-Ridaura. 1999. Sustentabilidad y manejo de recursos naturales. El marco de evaluación MESMIS (Sustainability and natural resource management. The MESMIS evaluation framework). Mundi-Prensa, S.A., Gira, IE-UNAM, México. 109 pp.] and adapted to animal production systems, as the guideline and framework to evaluate sustainability.

The principal component, namely energy input from grazing (eigenvalue 1.329) which comprises the indicators total area per goat (factorial value 0.664) together with net energy obtained from grazing (factorial value 0.903) allowed to differentiate significantly between semi extensive (SES), semi intensive (SIS) and intensive (IS) goat production systems.

Intensification of the GPS tends to be inefficient, especially in terms of net margin per litre of milk produced (p < 0.05). A higher degree of adaptability of IS (64.8%) derives from a higher investment on new production strategies. Likewise, higher self-management capacity of SES (60.9%) fosters standards of productivity (76.0%) and stability (42.9%). The SIS presented the highest equity values (67.8%).

On the whole, sustainability of GPS tends to decrease as the degree of intensification increases: SES = 57.3%; SIS = 55.7% and IS = 53.1%. The reduction of the dependency on external input alongside with the optimization of natural resources management would surely improve the standard of sustainability.     

纳罗克非洲狗尾草种子产量因子与产量的通径分析

采用多因素裂区试验设计,通过大样本相关、通径和逐步回归分析后,结果表明,纳罗克非洲狗尾草Setaria sphacelata cv. Narok的6个种子产量因子对种子产量的直接贡献大小排序为：x4（单位长度小花数）>x6（千粒重）>x1（花序长）>x2（单位面积生殖枝数）>x3（单位长度小穗数）>x5（单位长度种子数）,说明提高单位长度小花数、千粒重和花序长是最有效提高纳罗克非洲狗尾草种子产量的途径,其次提高单位长度小穗数、单位长度小花数和单位面积生殖枝数。