Single gene and gene interaction effects on fertilization and embryonic survival rates in cattle

Decrease in fertility and conception rates is a major cause of economic loss and cow culling in dairy herds. Conception rate is the product of fertilization rate and embryonic survival rate. Identification of genetic factors that cause the death of embryos is the first step in eliminating this problem from the population and thereby increasing reproductive efficiency. A candidate pathway approach was used to identify candidate genes affecting fertilization and embryo survival rates using an in vitro fertilization experimental system. A total of 7,413 in vitro fertilizations were performed using oocytes from 504 ovaries and semen samples from 10 different bulls. Fertilization rate was calculated as the number of cleaved embryos 48 h postfertilization out of the total number of oocytes exposed to sperm. Survival rate of embryos was calculated as the number of blastocysts on d 7 of development out of the number of total embryos cultured. All ovaries were genotyped for 8 genes in the POU1F1 signaling pathway. Single-gene analysis revealed significant associations of GHR, PRLR, STAT5A, and UTMP with survival rate and of POU1F1, GHR, STAT5A, and OPN with fertilization rate. To further characterize the contribution of the entire integrated POU1F1 pathway to fertilization and early embryonic survival, a model selection procedure was applied. Comparisons among the different models showed that interactions between adjacent genes in the pathway revealed a significant contribution to the variation in fertility traits compared with other models that analyzed only bull information or only genes without interactions. Moreover, some genes that were not significant in the single-gene analysis showed significant effects in the interaction analysis. Thus, we propose that single genes as well as an entire pathway can be used in selection programs to improve reproduction performance in dairy cattle.     

不同施肥措施对风沙土西拉葡萄产量与品质的影响

以贺兰山东麓风沙土栽培的4年生西拉(Syrah)为供试材料,研究了不同施肥措施对酿酒葡萄产量和品质的影响.结果表明,施肥对风沙土西拉葡萄产量都有增产作用,秸秆+有机肥+化肥处理增产效果最明显.施用秸秆各处理的单穗重和百粒重都比较高.施肥对西拉葡萄总糖度有显著影响,而对可滴定酸影响很小.秸秆+化肥、盐碱地肥和深施复合肥可显著提高果实总糖度,施有机肥可显著降低果实可滴定酸,从而提高糖酸比.因此,风沙土上施用秸秆是一项重要的增产措施,施用有机肥可以改善果实品质,有机无机肥配合是风沙土酿酒葡萄栽培重要的增产和培肥措施.     

Effect of nitrogen fertilization on quality markers of strawberry (Fragaria × ananassa Duch. cv. Aromas)

BACKGROUND: Nitrogen is an indispensable element for fruit metabolism and low or excessive N levels can affect the accumulation of the most important components that contribute to the flavour and aroma of the fruit. Among them, sugars, acids and volatile compounds can be considered quality markers. The objective of this study was to evaluate the effect of N fertilization on these quality markers of the fruit at two harvest dates. RESULTS: Strawberry plants were grown in a hydroponic system and N was applied as Ca(NO₃)₂ at concentrations of 0.3, 3 and 6 mmol L^?1 in the nutrient solution. Total soluble solids, soluble carbohydrates, amino acids and organic acids and volatile compounds of the fruit were analyzed. The fruits produced at 3 and 6 mmol L^?1 N had higher contents of esters, soluble carbohydrates and amino acids. The hexanal content increased with the 6 mmol L^?1 dose. The effect of fertilization was more marked at the second harvest date. CONCLUSION: The availability of N in strawberry plants affected the accumulation of quality markers. The fruits expected to have the best flavour and aroma, with both high levels of soluble carbohydrate and esters and low levels of hexanal, were obtained with 3 mmol L^?1 nitrate in the solution. Copyright © 2009 Society of Chemical Industry     

CFG桩加固软土地基的工程实践

采用CFG桩复合地基处理软弱土地基以提高地基承载力,通过对复合地基原理的阐述及CFG桩加固软土地基的特点和工程实践数据的分析,特别是经过对工程效果检验,说明FCFG桩复合地基处理办法能满足设计要求,并节省工程材料,降低工程成本,具有较好的经济效益和社会效益。     

不同施氯量对烤烟氯含量和产质量的影响

研究了不同施氯量对烟株氯含量、积累量及烤后烟叶产质量的影响。结果表明,随施氯量上升,烟株氯含量和积累量均表现为显著上升的趋势,整株氯含量和积累量与施氯量呈极显著的正相关。施氯量从0kg/hm~2提高到48kg/hm~2时,上部叶中的氯明显增加;但施氯量进一步增加到96 kg/hm~2时,中部叶和下部叶中的氯增加较为显著;茎和根中的氯随施氯量增加而表现出下降的趋势。施氯量在24 kg/hm~2时,烤后烟叶产质量较好,化学成分较为协调,不施氯或施氯太高均不利于烟叶质量的提高。     

南平烟区植烟土壤理化性状聚类分析与施肥对策

为了加强烤烟平衡施肥的分类指导和制定烤烟专用肥配方提供依据,根据烤烟种植面积分布,采集了南平烟区植烟土壤样品1101份,测定了主要理化性状,并运用聚类分析进行综合评价。结果表明,南平烟区植烟土壤偏酸,质地主要为壤土,交换性镁、有效铁、有效锰、有效铜含量丰富,有机质、全氮、全磷、速效磷、有效硫、有效锌含量中等,碱解氮、速效钾、交换性钙、水溶性氯含量较低,全钾、有效硼含量低。土壤pH变异最小,变异系数为7.71%;速效磷、水溶性氯和有效硼变异较大,变异系数分别达到80.30%、77.90%和75.87%。南平烟区植烟土壤可分成5个类群,各类群土壤均应施用氧化钙或与氧化镁交替施用调节pH。烤烟施肥上,第Ⅰ类群土壤应“控氮增钾,适磷补硼”,第Ⅱ类群土壤应“适氮增钾,补磷控硫”,第Ⅲ类群土壤应“适氮磷,重施钾,补硼氯”,第Ⅳ类群土壤应“适氮增钾,控磷硫,补硼氯”,第Ⅴ类群土壤应“适氮控磷增钾,补硼氯”。     

分散农户变量施肥配方系统设计与实现

针对当前国内农户分散经营模式下存在肥料偏施、施肥方式不科学等问题,基于地理信息系统(GIS)设计实现了一种适用于分散农户的变量施肥配方系统。系统采用关系型数据库SQL Server 2008作为内置数据库,实现土壤变异信息、作物历年产量信息、施肥配方信息等多种相关信息的存储、更新与查询。系统实现了空间插值、栅矢转换、数据融合以及叠加分析等功能,可以对土壤属性信息进行统计分析。同时,结合产量模型、施肥模型等知识模型自动生成分散农户具体条田施肥配方,施肥配方信息可通过指令传递给SMC6480控制器进行肥料的自动配比。通过实例应用,系统稳定可靠,能够很好地实现各功能模块。     

唐公沟矿中厚偏薄煤层刨煤机开采技术研究

对神东煤炭公司唐公沟煤矿4-2上煤层的地质条件进行分析,针对各个影响因素,采用加权求和的方法获得可刨性的综合量化值。得出结论:4-2上煤层属于易刨型煤层,适合刨煤机开采。进一步对4-2上煤层进行开采技术选择,设计出刨煤机开采的配套设备,对现场有较高的参考价值。     

黄土地基中超长钻孔灌注桩工程性状研究

通过对黄土地基中超长钻孔灌注桩竖向承载力静载试验 ,桩身轴力传递和桩侧阻力发挥的测试 ,探讨了高结构黄土地基中超长钻孔灌注桩的承载力性状 ,受施工质量影响的桩身轴力传递规律和侧阻力发挥性状 ,对黄土地基中钻孔灌注桩的设计、施工和深入研究具有很大意义。     

Postnatal phenotype of dairy cows is altered by in vitro embryo production using reverse X-sorted semen

Abnormal fetuses, neonates, and adult offspring derived by assisted reproductive technologies have been reported in humans and mice and have been associated with increased likelihood of certain adult diseases. To test the hypothesis that bovine females derived by assisted reproductive technologies have altered postnatal growth and adult function, a retrospective cohort study evaluated survival, growth, and production traits of offspring derived by in vitro embryo production (IVP) with conventional (IVP-conv) or reverse X-sorted semen (IVP-sexed), multiple ovulation and embryo transfer, and artificial insemination (AI) in a large dairy herd. Live calves produced by IVP were born slightly heavier compared with AI calves. In addition, IVP-sexed calves had a higher cumulative mortality from 90 to 180 d of age compared with AI offspring. Mortality of IVP-conv and multiple ovulation and embryo transfer offspring was intermediate and not different from AI or IVP-sexed offspring. The altered phenotype of offspring from IVP-sexed extended to adult milk production. Cows derived by IVP-sexed produced less milk, fat, and protein in their first lactation compared with dairy cows derived by AI. Additionally, females born to nulliparous dams had a distinct postnatal phenotype compared with offspring from parous dams even when data were restricted to offspring of surrogate females. In conclusion, procedures associated with in vitro production of embryos involving use of reverse-sorted spermatozoa for fertilization result in an alteration of embryonic programming that persists postnatally and causes an effect on milk production in adulthood. Thus, some benefits of reverse-sorted semen for genetic improvement may be offset by adverse programming events.