基因枪转化技术在棉花遗传转化上的应用

将外源基因导入棉花的方法很多,目前,最受瞩目的是农杆菌介导法和基因枪转化法。本文对基因枪转化法的基本原理、发展情况、技术的优缺点、影响转化率的主要因素以及此方法在棉花遗传转化中的研究动态进行了分析。     

根癌农杆菌介导白细胞介素-4基因转化甘蓝(Brassica oleracea L.)研究

利用根癌农杆菌介导法,以白细胞介素-4(interleukin-4,IL-4)基因转化中甘11号甘蓝.本研究对可能影响il-4转化率的外植体类型、外植体的预培养时间、农杆菌的侵染时间以及外植体与农杆菌的共培养时间进行了优化.试验结果表明:il-4基因对带1～2 mm子叶柄的子叶的转化率显著高于下胚轴;带柄子叶在预培养1 d、侵染3 min、共培养1 d时,转化效果最好,转化率达23.3%;下胚轴在预培养1～3 d,侵染3～5 min,共培养1～2 d时,转化效果较好,转化率最高可达13.3%.经PCR检测及PCR-Southern杂交,初步证明目的基因il-4已经转入甘蓝的再生植株.转il-4基因甘蓝的PCR阳性再生植株已经开花并产生了后代.     

Feature of Iteration Convergence in Concurrent Design

A parameter, proportion of all work on every task in each stage, is introduced to build a new WTM. Based on this new WTM, this paper deeply analyzes the relationships between the eigenvalue and the convergence rate of the total work, and the relationships between the eigenvector and the total work. By comparative analysis between the existing WTM and new WTM, it is investigated that this parameter causes the increasing total work and decreasing convergence rate, and the existing WTM is just a speciality when this parameter becomes the maximum. Finally, the generality of the new WTM is tested by the design process of the camera.     

Graphic Transfer Technique Applied in the Grinding Robot

The Graphic transfer technique applied in control software of a profile-followed robot for grinding turbine surface is described. Projection transformation in any axis of 3D camber on a display coordinate is realized by using homogeneous transfer matrix, which provides user with visual information of grinding and processing. 2D graphic linear transfer technique is used to provide user with uniform NC programming format and to carry out 2D grinding process for 3D profile. 3D non-linear transfer technique is successfully used to solve a series of difficult problems including coordinate transfer of controlled points in multi-coordinate system, the attitude adjustment of grinding and constant pressure grinding. All the mathematics methods used are demonstrated in practice feasible and efficiently.     

The Ledge Structural Models of FCC:BCC Partially Coherent Interface

The structure of FCC: BCC partially coherent interface is simulated by computer. The results show that the interface structure is varied with the orientation relationships. The structural models of varied orientations are made, which are defined by the lattice parameter ratio afcc/abcc= 1. 26 and ranged from K-S to N-W orientation relationship. The amount of deviation of the apparent habit plane from atomic habit plane {111}fcc is a function of orientation,and ranges from ca. 12 degrees to ca. 30 degrees. Computer simulations also found that the misfit dislocations could not be certain to exiet on the FCC:CC partially coherent interface.     

Recent Progresses in the Studies of Transfer Genes in Alfalfa

Genetic transfer in plants means inducing exogenous genes into recipient plants by molecular biological methods and producing exotic genetic characters in recipient plants. Transgenic technique can more quickly ,effectively and directly get a breed than traditional breed system. The technique has developed the focus of breeding researches in plants. This paper reviews progresses, problems and resolutions in the studies of transfer genes in alfalfa in recent years.     

正交设计优化根癌农杆菌介导的玉米遗传转化体系

采用GUS基因瞬时表达检测的方法,利用正交试验法对玉米根癌农杆菌介导的玉米遗传转化体系的菌液OD值、侵染时间、AS浓度、共培养时间4个因素在3个水平上进行优化试验。通过对试验结果进行直观分析,方差分析和因素内多重比较分析,得到了稳定的转化体系,即菌液OD值0.6,侵染时间30min,AS浓度200μmol/L,共培养时间2d。采用优化后的玉米转化体系进行试验,通过PCR验证,得到了转基因植株,初步建立了农杆菌介导的玉米遗传转化体系。     

以棉花茎尖分生组织为受体进行基因枪轰击转化的研究

以棉花茎尖分生组织为受体进行基因枪遗传转化,在不受宿主基因型范围和操作时间的限制等方面优于农杆菌介导法和花粉管通道技术。影响棉花茎尖分生组织基因枪遗传转化率的因素较为复杂,轰击前,外植体制备需考虑茎尖分生组织的取材时间、下胚轴保留的长度、外源生长调节剂及活性炭的使用量,以保证其正常生长;轰击后,抗生素筛选的浓度、筛选培养基的转换时间和抗性苗的壮苗也会影响转化效率;此外,DNA和钨粉或金粉的质量、基因枪参数及操作等对转化效果都有一定的作用。除对影响茎尖分生组织基因枪转化率的因素分析以外,还对近年来在棉花茎尖分生组织遗传转化中的最新动态进行了综述,并对目前存在的问题加以讨论。     

影响不结球白菜真空渗入转基因频率的几个因素

采用不同发育阶段的植物材料及不同菌株，将马铃薯胰蛋白酶抑制剂基因(PinⅡ)和蜘蛛杀虫肽(SIP)基因双价转入49菜心，以除草剂抗性株出现频率，以及目的基因的PCR鉴定结果为依据，对影响不结球白菜-49菜心真空渗入转化率的一些因素进行了探索。结果表明植株生长阶段和真空渗入处理时间、所用菌株类型均对转化率有影响，其中以开花初期的植株，利用胭脂碱型农杆菌介导，真空渗入5min的处理方法转化效率最高。