生产条件下安哥拉山羊胚胎徒手分割研究

生产条件下,徒手二分割安哥拉山羊桑椹胚和囊胚,并将裸半胚手术移植于受体羊子宫角。１９９３年用０．５％链霉蛋白酶处理胚胎１～６ｍｉｎ软化透明带后,在玻璃培养皿中的含１２．５％蔗糖和５％新生犊牛血清（ＮＣＳ）的ＰＢＳ液内分割,将３３枚半胚移植到２１只受体,有２只受体妊娠。１９９４年用０．２５％链霉蛋白酶处理胚胎０．５～１ｍｉｎ软化透明带后或不经处理而直接在磨砂玻璃皿中的含２０％血清的ＰＢＳ液内分割,移植受体３４只,有１０只受体产羔（２９．４％）,共产羔１１只,其中１对为同卵双生,半胚成羔率为２０．０％（１１／５５）。１９９５年,囊胚不经处理直接在磨砂玻璃皿中的含２０％ＮＣＳ的ＰＢＳ液内分割,半胚成对移植于受体羊黄体侧子宫角,产羔受体率为５０．０％（１３／２６）,共产羔１６只,其中３对为同卵双生,半胚成羔率为３０．８％（１６／５２）,胚胎成羔率为６１．５％（１６／２６）。     

涉农高校技术转移中心管理模式研究

针对农业技术的特点,农业科技成果转化有其自身的规律和特征,涉农高校技术转移管 理部门要建立推转一体化的管理模式。以安徽农业大学和江南大学的模式,有效的将横向合同 管理,公益推广体系、知识产权建设及平台搭建有机结合起来。     

Natural hybridization between wheat (Triticum aestivum L.) and its wild relatives Aegilops geniculata Roth and Aegilops triuncialis L.

BACKGROUND

Cultivated bread wheat (Triticum aestivum L.) spontaneously hybridizes with wild/weedy related Aegilops populations, but little is known about the actual rates at which this hybridization occurs under field conditions. It is very important to provide reliable empirical data on this phenomenon in order to assess the potential crop–wild introgression, especially in the context of conducting risk assessments for the commercialization of genetically modified (GM) wheat, as gene flow from wheat to Aegilops species could transfer into the wild species genes coding for traits such as resistance to herbicides, insects, diseases or environmental stresses.

RESULTS

The spontaneous hybridization rates between wheat and A. geniculata and A. triuncialis, which are very abundant in the Mediterranean area, have been estimated for the first time in the northern part of the Meseta Central, the great central plateau which includes the largest area of wheat cultivation in Spain. Hybridization rates averaged 0.12% and 0.008% for A. geniculata and A. triuncialis, respectively. Hybrids were found in 26% of A. geniculata and 5% of A. triuncialis populations, at rates that can be ≤3.6% for A. geniculata and 0.24% for A. triuncialis.

CONCLUSION

The detection of Aegilops spp.–wheat hybrids in Aegilops populations indicates that gene flow can occur, although wheat is considered a crop with a low-to-medium risk for transgene escape. These data on field hybridization rates are essential for GM wheat risk assessment purposes. © 2023 Society of Chemical Industry.     

基于深度学习的病虫害智能化识别系统

我国农作物种植覆盖面广、分散度高,病虫害发生种类多、区域性发生规律复杂,传统的人工鉴定技术从效率、能力与精度方面均难以满足新形势下重大病虫测报要求。针对这一实践需求,以测报灯下害虫图像数据库(约18万张)、田间病虫害图像数据库(约32万张)为基础,构建了基于深度学习方法的病虫害种类特征自动学习、特征融合、识别和位置回归计算框架,并研发了移动式病虫害智能化感知设备和自动识别系统。通过近2年的精确度和实操运行效率检验,该系统在自然状态下对16种灯下常见害虫的识别率为66%～90%,对38种田间常见病虫害(症状)的识别率为50%～90%。随基础数据库的不断丰富、神经网络深层特征提取的不断完善,该系统有望进一步提高识别准确率,从而真正实现田间病虫害识别自动化、智能化和高效率。     

Factors Associated with Survival in Septicemic Foals: 65 Cases (1988–1995)

In order to identify variables obtained at admission that could be used to predict survival in septicemic foals, medical records of 65 foals diagnosed with septicemia were reviewed. Initially, variables were analyzed independently (univariate analysis) for association with survival. Of the physical examination and historical data examined using univariate analysis, the ability to stand at admission, respiratory rate ≥ 60 breaths per minute (bpm), and normal-appearing mucous membranes were significantly associated with survival. Foals with history of induced parturition were significantly less likely to survive. The following hematologic and serum biochemical variables determined at admission were significantly associated with survival: white blood cell count a 6,000 cells/μL, neutrophil count <4,000 cells/μL, serum albumin concentration <2.2 g/dL, serum glucose concentration <120 mg/ dL, blood pH ≥ 7.35, and positive base excess. The administration of plasma at admission was significantly associated with survival. Stepwise multiple logistic regression analysis was performed to evaluate the association between survival and variables identified as significantly associated with survival in bivariate analysis. The final multivariate model selected included the variables standing, duration of clinical signs (24-hour intervals) prior to admission, respiratory rate a 60 bpm, neutropenia (> 4,000 cells/μL), and neonatal age category. The probability of survival was significantly increased for foals that were standing, had a respiratory rate a 60 bpm, and that had a neutrophil count <4,000 cells/μL at admission. Probability of survival was significantly decreased for foals that had a longer duration of clinical signs prior to admission. For each 24 hours of duration, the estimated risk of death was increased by 5.8-fold.     

控释氮肥和尿素配比对不同品种夏玉米氮素累积、转移及其利用效率的影响

在黄淮海夏玉米生产区,不同控释氮肥和尿素的配比下,研究不同氮效率玉米品种的产量及其花前花后干物质和氮素累积分配规律,以及相应的氮素利用效率与经济效益,为该区域夏玉米氮肥高效施用提供理论与技术依据.试验采用裂区设计,周期为两年,以施氮处理为主区,设置0、180、300 kg·hm-23个施氮水平,并在180 kg·hm-...     

转基因动物研究进展

转基因动物是现代生物技术中一个极其重要的研究领域，目前已经有转基因小鼠、兔、绵羊、山羊、猪、牛、鸡和鱼等多种转基因动物问世。本文综述了转基因动物的制作方法、转基因动物的应用研究以及所取得的重要成就，并指出了转基因动物存在的主要问题，展望了其发展前景。     

胚胎冻融技术及其在我国肉羊产业中的应用

胚胎冻融技术可使胚胎移植不受时间、地点的限制,从而达到提高胚胎移植效率的目的,研究和优化胚胎冻融技术对胚胎移植工程的发展具有重要的意义。主要对胚胎冻融技术的原理、特点及其在肉羊产业中的应用情况进行了综述,旨在阐明胚胎冻融技术对我国肉羊产业发展的重要作用。     

基于深度学习算法的京津冀地区综合干旱评估模型构建

及时准确的干旱评估对社会经济发展和农业生产具有重要的指导意义,当前的干旱评估指标通常仅考虑植被或降水等单方面影响因素,在实际干旱评估中存在一定的局限性。本研究综合考虑降水、温度、地形等多个干旱致灾因子,以主要产粮基地京津冀地区为例,基于2007-2017年地表温度（Land Surface Temperature,LST）、归一化植被指数（Normalized Difference Vegetation Index,NDVI）以及降水等多源数据,利用深度学习框架Tensorflow构建以标准化降水蒸散发指数（Standardized Precipitation Evapotranspiration Index,SPEI）为目标值的综合干旱评估模型。利用决定系数（R2）和均方根误差（RMSE）对模型进行测试;利用站点标准化降水指数（Standardized Precipitation Index,SPI）、土壤相对湿度数据以及2016年京津冀地区的气象灾害数据,从时间和空间上对模型的可靠性进行验证。结果表明：模型的训练集和测试集在不同月份上均表现较好（R2均大于0.5而RMSE均小于0.55）。模型输出的综合干旱指数（Comprehensive Drought Index,CDI）在密云站上与SPI和SPEI接近,变化趋势基本一致,并且与站点SPI和土壤相对湿度的相关系数分别大于0.7和0.4,均通过了0.01水平的显著性检验。空间上,相较于SPEI,CDI计算的2016年3-7月京津冀地区干旱事件结果与实际情况符合度更高,表明该模型适用于京津冀地区干旱评估。     

影响胚胎移植成功率的主要因素

本文针对在胚胎移植过程中可能预见的各种影响胚胎移植技术的实施的因素进行了较为全面的分析,并针对不同影响因素提出了自己独特的见解,以期在生产实践中对胚胎移植技术的应用和推广有所借鉴。