家畜繁殖生物技术研究现状及趋势

牛胚胎移植技术已趋于成熟。我国新疆牧科院用一步细管法移植牛冻胚受胎率达41%;牛和羊鲜胚四分胚移植也产下1头犊牛和6只羔羊。家畜体外受精,因卵子体外成熟和受精卵体外培养尚不过关,目前仍停留在实验室阶段。胚胎性别鉴定,1990年Koopman发现单拷贝基因,该基因是Y染色体的性决定区,命名为SRY,可利用PCR技术制成雄性特异DNA探针盒,进行马、牛、羊、猪早期胚胎性别鉴定。北京农学院等单位用PCR扩增牛SRY序列进行奶牛胚胎性别鉴定准确率达100%。英、日、法等国已获得牛胚胎细胞核移植后代;我国也获得1只核移植兔。北农大和新疆牧科院合作以绵羊精子为载体导入牛生长激素基因rMTbGH DNA成功,外源基因整合率为3%。     

Differences in Wheat Cultivar Response to N Supply. I: Differences in Grain Yield Formation

Two-year field trials with winter wheat cultivars Batis and Toronto were conducted in Southern Bavaria, Germany, to investigate the possible causes of cultivar differences in response to N supply varying in total amount and time of application. Cultivar-related differences in grain yields were observed in treatments with low and medium N supply. High doses of N supply resulted in grain yield adjustment or grain yield advantage for cv. Toronto. The results of this study revealed a consistent, genotypic pattern in response to N fertilization in spite of strong seasonal effects. Systematic modifications in canopy growth rates in response to N supply were of particular relevance and a main factor for differences in tillering intensity resulting in modified stand densities. In the present study, cultivar differences in spike development and interactions with N supply related more to abortion than to initiation processes for number of spikelets and number of flowers per spikelet. High grain density (grains per m²) of cv. Toronto was evident during reproduction stages even under conditions of medium N supply. However, decreased growth rates during the later part of grain filling in combination with low 1000 grain weight, which was barely modified by N fertilization, allowed only partial utilization of this potential. It is assumed that sink limitations were of particular relevance for grain yield development in cv. Toronto, while cv. Batis combined a less intense response to N supply with more stability in the development of grain yield components.     

Quick detection of sex determining region protein gene in mouse fetuses

AIM: To detect quickly the Y-chromosome specific sex determining region protein (Sry) gene in mouse fetuses on embryonic day 14.5 with a PCR method. METHODS: We designed specific primers with the OLIGO 5. 0 software. Templates were prepared in 30 minutes by the following way. About 1 mg embryonic tissue but not fetal liver was suspended, and treated with 200μL of lysis buffer, consisting of PCR buffer containing 20 mg/L proteinase K, 0. 5% NP-40, and 0.05% Tween 40, at 60°C for 15 minutes, heated for 5 minutes at 100 °C, 10μL was used as template. The PCR react ion was performed in 50μL, using two sets of primers specific for Sry gene (chromosome Y) and IL-3 gene (chromosome 11) . PCR conditions and cycle numbers were optimized. The assessment of the results was done by electrophoresis in 3% agarose run at high voltage. The specificity of the method was conf irmed by fluorescent in situ hybridization (FISH) using a specific male probe on embryonic tissue cells. RESULTS: Electrophoresis showed that PCR product of male control DNA consisted of a 649 bp product representing the IL-3 gene and a 444 bp product representing the Y-specific Sry gene, female control DNA only one 649 bp product. Fetuses with two bands matching those as seen inmale control DNA are the presumpt ive male fetuses. Fetuses, only the IL-3-associated 649 bp band, are the presumptive female fetuses. These were confirmed by FISH. The ent ire procedure took <3. 5 h. CONCLUSION: The established PCR assay offers a quick, simple, accurate, and sensitive detection of sex determining region protein gene in mouse fetuses. This method allowed the preparation and culture of pure male and female hematopoietic stem cells from fetal tissue.     

罹患口腔炎乌苏里蝮的相关生理学指标分析

口腔炎是人工养殖蛇类的常见病之一,为了深入了解和尽早做好预防工作,对罹患口腔炎的成年雄蛇乌苏里蝮(Gloydius ussuriensis)进行解剖观察,并检测了相关器官的系数、血液学指标和激素等。结果表明:整体肥满度、躯体肥满度、肾系数等数值罹患口腔炎蛇略高于健康蛇;而肝系数、精巢系数和脂肪体系数等罹患口腔炎的蛇低于健康雄蛇,且前两者呈显著性差异,后者呈极显著性差异。性激素检测结果显示罹患口腔炎的蛇血液睾酮和雌二醇含量均低于健康蛇,且均具极显著性差异。血细胞指标中,红细胞数量、红细胞分布均差、白细胞总数、淋巴细胞数量和淋巴细胞比率等均为罹患口腔炎的蛇高于健康雄蛇,且具显著性差异,但嗜中性粒细胞和淋巴细胞的比值(NLR)、中性粒细胞数量和比率、中间细胞数量及其比率均为患口腔炎的雄蛇低于健康蛇,且具显著性差异。结论:口腔炎不仅影响了主要代谢器官的器官系数的变化,而且血液多项指标和性激素水平也有明显差异。性激素含量的变化将对乌苏里蝮的正常生殖繁育产生不可忽视的影响。另外,NLR和红细胞分布宽度2个血常规指标可作为早期诊断炎症发生的首选参数。     

蓝果忍冬成熟期结合力变化规律的测试分析

为了弄清成熟蓝果忍冬结合力的特性和变化规律、给机械化收获提供技术依据,在蓝果忍冬成熟期间对4个常见品种果实结合力进行了为期16天的跟踪测试。通过分析研究得出:所测试的4个蓝果忍冬品种的结合力分布在0.1~1.7 N之间(P0.05),各品种结合力分布区间略有不同,所测试的野生阿尔泰忍冬、蓓蕾的结合力高于蓝鸟和长白山野生蓝靛果忍冬;各品种结合力随时间呈现出不同程度的下降趋势;同一天内下午的结合力显著大于上午的结合力(P0.05);晴天与阴雨天的结合力无显著性差异。通过因子分析,可将影响结合力的因素测试时间、上下午、相对湿度、温度及天气状况转换成环境因子和时间因子。     

大英县近10年降水变化特点分析

利用大英县2004 ～2013年逐日降水资料,采用统计学方法,对大英近10年降水的实际变化特点、季节差异等进行简要阐述,并对直接影响工农业生产和人们生活、外出旅游以及交通运输等的暴雨进行了重点统计分析.结果表明,2004～2013年大英县年雨量和暴雨日数分布特征均呈单峰型,峰值均出现在7月;暴雨雨量、雨日与年降雨量存在明显的正相关关系;夏季同月雨量差距巨大;初秋的9月出现暴雨的概率较大,月雨量、暴雨出现次数均为全年的次高值;大英县出现秋绵雨的概率达50％,集中出现在9、10月.     

Soil property differences among high‐ and average‐yielding soya bean areas in Arkansas,USA

Soya bean [Glycine max (L.) Merr] yields >6719 kg/ha (100 bu/ac) have only recently and infrequently been achieved. Quantifying soil property differences between high‐ and average‐yielding areas can help to further identify non‐plant‐related properties contributing to soya bean yield potential. The objective of this study was to evaluate the effects of region and soil depth on soil property differences between high‐ and average‐yielding areas. In each of the seven regions of the ‘Grow for the Green’ yield contest in Arkansas, prior to or just after harvest in 2014 and 2015, soil samples were collected from the top 20 cm of one contest high‐yield (HY ) area that was in close proximity to an average‐yield (AY ) area. Across all regions and both years, soya bean yields differed (P  <  0.05) between yield areas, averaging 4701 and 5498 kg/ha in AY and HY areas, respectively. Averaged across soil depth and years, numerous soil properties differed (P  <  0.05) between HY and AY areas within at least one of seven regions. Total soil C content was at least 20.2% greater in the HY than in the AY area in three of seven regions. Extractable soil P content was, on average, 19.4 kg/ha greater in HY than in AY areas in three of the seven regions. Results from this study have the potential to help producers better understand soil properties that contribute to or hinder achieving ultra‐high (>6719 kg/ha) soya bean yields.     

基于支持向量机的农机装备水平差异分类研究

针对黑龙江垦区各农场农机装备水平不平衡差异问题,采用支持向量机多类分类和主成分分析相结合的方法进行研究。将农机装备水平分为3个等级水平,从总量、速度和均量3方面选取10个评价指标;采用主成分分析法确定5个主要合成指标;建立多类分类支持向量机新模型,把新模型转化成一个互补问题,利用Lagrangian隐函数进一步转化成一个强凸的无约束优化问题,采取快速牛顿算法进行求解;利用实证调研数据,从发展差异度的角度对黑龙江垦区98个农场农机装备水平的差异进行多指标分析,在分类的准确度和训练速度方面都有很好的表现。     

人工养殖西伯利亚狍肠道微生物组成的雌雄差异

肠道微生物是一个复杂的生态系统,与宿主的健康、疾病以及其他因素有着密切的关系。目前,关于肠道菌群结构和功能的研究较多,但是对西伯利亚狍肠道菌群的研究还未见报道。西伯利亚狍(Capreolus pygargus)属于反刍动物,有独特的消化特性和微生物群来帮助它们适应高纤维的食物。本研究利用高通量测序技术在Illumina MiSeq平台上对14只狍肠道微生物进行16S rRNA基因分析。结果表明:个体样本中门类组成的差异,雌性个体JY3和雄性个体JY9除Firmicutes,Bacteroidetes,Proteobacteria这3类菌群外,其他门类菌群所占比例都很低。在科水平上,雌性个体中Ruminococcaceae在JY7和JY13肠道内含量相对较少,Bacteroidaceae在JY7,JY10和JY13中含量较高。雄性个体中Ruminococcaceae在JY11和JY14肠道内含量较少,Prevotellaceae在JY4中含量较少。在属水平上,雌性个体特有的菌属为Roseburia,Alloprevotella,Lachnospiraceae_incertae_sedis和Coprococcus;雄性个体特有的菌属为Fusobacterium,Succiniclasticum,Streptococcus和Clostridium sensu stricto。Alpha多样性分析表明,Ace指数范围2128.93—772.98,Chao1指数范围2128.89—785.27,Shannon指数范围5.44—3.78,Simpson指数范围0.07—0.01。在不同物种分类水平上,雌雄狍肠道内的优势菌群有些不同。PCoA(principal co-ordinates analysis)分析显示,狍样本几乎混在一起,没有明显差异。     

基于PSR模型的兰州市土地生态安全时空差异评价

研究了兰州市2006~2013年土地生态安全的时空差异。主要依据PSR模型建立评价指标体系,运用熵权法与综合评价法对不同时期兰州市及各县区土地生态安全状况进行分析。结果表明:(1)兰州市土地生态安全由2006年的"恶劣"状态转变为2013年的"良好"状态;(2)土地生态压力指数从0.176下降为0.145,土地生态状态与土地生态响应指数分别从0.063、0.160提升到0.295、0.290;(3)区域内空间分布差异较为明显,土地生态状态改善与响应增强主要集中在土地生态压力过大的地方。据此可知,兰州市土地生态结构和功能基本完善,已步入良好阶段,但是各县区土地生态空间分布差异较大。