大豆组织培养再生系统的研究进展

大豆因其愈伤组织难以分化、原生质体再生困难等因素,其再生体系一直不够完善。直到20世纪80年代初期,才成功建立了大豆的体细胞胚胎发生和器官发生再生系统。80年代末期原生质体培养获得突破。介绍了大豆器官发生再生系统、体细胞胚胎再生系统和原生质体再生系统的研究进展;对这3种再生系统进行遗传转化的优缺点作了比较;并提出了关于大豆遗传转化再生系统的几点展望。     

转基因技术在大豆育种上的应用与研究

近年来,转基因技术在大豆上的研究重点主要集中在建立高效再生体系和稳定地遗传转化体系方面,随着遗传转化技术的发展,我国已获得了抗病、抗虫转基因的大豆植株并取得突破性进展。笔者就大豆遗传转化在受体系统(器官发生受体系统、体细胞胚胎发生受体系统、原生质体受体系统)以及转化方法(农杆菌介导法、基因枪法)等方面的研究进展情况进行了综述,并对今后大豆转基因研究方向进行了探讨。     

茶树体细胞胚发生的研究进展

体细胞胚胎发生(somatic embryogenesis, SE)是植物特异性的发育过程和植株再生的关键因子,其对于茶树的育种及繁殖具有重要意义。为了系统认识茶树体细胞胚胎发生的适宜培养条件,本研究总结了茶树体细胞胚发生的研究进展;综述了影响茶树体细胞胚胎发生的主要因素;剖析了茶树体细胞胚胎诱导过程中存在的问题;并对如何解决这些问题提出了研究展望。以期为茶树遗传转化体系的建立和新品种培育提供重要的理论和技术支撑。     

高渗处理对不同基因型大豆未成熟子叶基因枪法转化效果的影响

为了进一步优化以未成熟子叶为外植体的大豆遗传转化技术体系,研究了高渗剂种类、高渗处理时间,以及轰击后高渗培养时间对不同基因型大豆未成熟子叶基因枪转化效果的影响。结果表明,高渗剂种类极显著地影响体细胞胚数,基因型间体细胞胚胎发生率存在显著差异,而大豆基因型与高渗剂种类间在体细胞胚胎发生率和胚数上都存在极显著的互作。对大豆品种合丰25未成熟子叶进行高渗处理24h时,体细胞胚胎发生率极显著地高于7h和0h处理;胚数在3种高渗时间处理间没有显著差异。基因枪轰击后高渗培养5d和7d时大豆5个基因型间在体细胞胚胎发生率方面存在极显著差异,均以吉育71最高,其次是合丰25和黑农51,绥农28和吉育75较低。吉育71的体细胞胚胎发生率在轰击后高渗培养5d处理中最高,而其它基因型的体细胞胚胎发生率不受轰击后高渗时间的显著影响。     

葡萄体细胞胚发生及遗传转化体系研究进展

葡萄因其优良品质被广泛种植,是世界上重要的果树之一。随着现代生物技术的研究与应用,一个稳定高效的再生体系和遗传转化体系是进行葡萄相关生物技术研究的基础。葡萄体细胞胚发生具有遗传物质稳定、单细胞再生为植株等特点,适合作为一个稳定高效的再生途径;而葡萄的遗传转化体系的建立则是近年来葡萄生物技术的研究与应用的重要核心。本综述在讨论体细胞胚发生与遗传转化之间关系的基础上,综述了葡萄体细胞胚发生和遗传转化的研究进展。总结讨论了多年来葡萄体细胞胚发生和遗传转化过程中的不同方法及影响因素。此外,还阐述了体细胞胚发生和遗传转化共有的一些问题如:效率低、植株再生难等,在此基础上对两大体系的改良及发展进行了展望,为后续遗传转化研究提供指导。     

菜豆再生体系及遗传转化体系研究进展

菜豆分子育种及功能基因组学分析需要高效稳定的再生体系和遗传转化体系。归纳了近年来国内外菜豆再生体系及遗传转化体系的研究进展。首先阐述了菜豆再生方法及研究现状,其中包括基于器官发生和体细胞胚发生不同途径菜豆再生体系的建立和相关的影响因素。其次概括了农杆菌介导法在菜豆遗传转化方面的研究进展,并分析了影响农杆菌介导遗传转化效率的主要因素,包括受体外植体类型和外植体损伤、农杆菌菌株及菌液浓度、共培养条件(时间、温度、光照时间)、乙酰丁香醇浓度等。然后叙述了有关基因枪介导菜豆遗传转化的研究进展。最后对目前菜豆再生体系和遗传转化体系存在的难题进行了总结,以期为建立菜豆的高效离体再生体系和遗传转化体系提供重要参考。     

大豆组织和细胞培养研究进展

从大豆组织培养的培养基选择、基因型和外植体类型培养差异、器官和胚胎发生再生植株、花药和花粉及 原生的南体培养再生植株、体细胞无性系变异体选择和基因转化等方面综述了大豆作物组织和细胞培养所取得的进展，并对今后的研究提出了建议。     

海岛棉愈伤组织诱导及分化的影响因素初探

本研究以新疆自育海岛棉品种新海16无菌苗下胚轴为外植体材料,进行愈伤组织诱导、分化及再生植株的初步研究,筛选出适合于海岛棉体细胞胚胎再生的培养体系。结果表明,最佳诱导愈伤组织及分化配方为MSB附加0.1mg/L2,4-D及0.05mg/LKT,分化率达到88%;于MSB1附加0.01mg/LKT及0.3mg/LNAA中对胚性愈伤组织进行增值培养;由MSB2附加0.1mg/LIBA中可分化出成熟体细胞胚胎及再生植株,分化率达73%。本研究通过体细胞胚胎发生途径获得了海岛棉再生植株,为海岛棉遗传转化体系的建立及分子育种奠定了基础。     

大豆遗传转化系统的研究进展

综述了大豆的遗传转化的受体系统和转基因方法的最新研究进展，并进一步探讨了大豆遗传转化的主要问题及对策。在大豆遗传转化研究中存在着适合遗传转化的再生系统不完善、遗传转化效率较低且重复性差、大豆受体基因型匮乏等问题，因此建立高效和稳定的大豆组织培养体系，使之广泛适于生产上栽培大豆品种的遗传转化，另外将目前转基因策略中单价基因改为多价基因，可能是解决上述问题的有效途径。     

探析植物体胚发生的关键基因

体细胞胚胎是植物离体再生的高效方式及遗传转化的理想受体,也是进行科学研究的理想体系;但是从体细胞转变为胚性细胞的过程是复杂的基因调控网络调控的,在这其中,BABY BOOM/WUSCHEL/LEAFY COTYLEDON/MYB115等转录因子处于体胚调控网络的上游,能够带动下游相关基因的响应从而启动了体细胞胚胎的发生,起着"画龙点睛"的关键作用,是启动体胚发生"按钮"和调控体胚发育的"开关"。本综述分析了上述关键基因在启动体细胞胚胎发生及体胚发育和器官再生等过程中的作用,及探讨了从分子水平调控体胚发生的研究体系。认为,在化学诱导表达体系下操纵BABY BOOM和WUSCHEL基因的表达是启动体胚发生及提高植物再生能力的最有效的调控系统,无论同源和异源表达均表现出明显的功能和诱导体胚发生形成的作用,对于科研和生产均具有重要的价值和意义。     

Transgenic fertile plants of soybean [Glycine max (L.) Merrill] obtained from bombarded embryogenic tissue

This work describes the production of transgenic, fertile plants of soybean [Glycine max (L.) Merrill]. The transformation method combines the advantages of somatic embryo genesis with the efficiency of particle bombardment of tissues that have a great capacity for in vitro proliferation and regeneration. The results described here represent the first report of transformation of soybean cultivars recommended for commercial growing in South Brazil using somatic embryogenesis, and may open the field for the improvement of this crop in this country by genetic engineering. This revised version was published online in August 2006 with corrections to the Cover Date.     

棉花原生质体培养与体细胞杂交研究进展

棉花原生质体培养已在多个棉种上取得成功,体细胞杂交也取得了较大的进展,创造出多个种间体细胞杂种,为棉花遗传改良提供了丰富的种质资源.结合本实验室的研究进展,综述了棉花原生质体培养和体细胞杂交的基本技术、研究现状、存在问题和应用前景,为棉花基因工程和细胞工程研究提供有益的借鉴.     

RAPD-based detection of genomic instability in soybean plants derived from somatic embryogenesis

Random amplified polymorphic DNA (RAPD) markers were used to evaluate genetic stability of regenerants of soybean plants obtained through somatic embryogenesis using 180 μM 2,4‐dichloro‐phenoxy acetic acid. Twenty primers were used to screen 44 regenerants from the cultivar ‘Spring’ and 28 from the cultivar ‘CAC‐1’. Three primers were polymorphic for two of the ‘Spring’‐derived regenerants, with a somaclonal frequency of 4.5%. Four primers were polymorphic for the ‘CAC’‐l‐derived regenerant, with a somaclonal frequency of 3.57%. The results indicate the usefulness of RAPD markers to detect genetic instability in soybean primary regenerant plants derived from somatic embryogenesis, and as a certification tool for monitoring genetic stability during the regeneration process.     

农杆菌介导陆地棉转化和再生体系的研究进展

陆地棉通过体细胞胚胎发生的农杆菌介导转化体系的主要瓶颈在于:基因型限制、转化周期长、胚胎发生率低、易出现畸形胚等问题.针对这些问题,研究者对传统转化体系的各个环节进行了优化,并在拓展受体基因型、筛选高频再生品(种)系或株系、选择不同的组织或器官做受体和建立新的不依赖于组织培养和基因型限制的农杆菌转化体系等方面进行了探索...     

大豆品种合丰25体细胞胚发生条件的优化

为优化大豆体细胞胚再生植株的条件,提高大豆遗传转化的效率,本研究选用大豆品种合丰25为试验材料,针对影响体细胞胚诱导的3个关键因素pH值、2,4-D浓度及光照条件进行体细胞胚发生频率的研究。结果表明:pH值、2,4-D浓度、光照条件这3种因素的不同处理对体细胞胚的诱导影响显著,其幼胚的发生频率最高为70.70%、最低为3.70%。当pH值为7.0、2,4-D浓度为20mg/L,黑暗培养最有利于合丰25体细胞胚的诱导,其胚的发生频率为70.70%,明显高于其他处理。     

长江和黄河流域棉区棉花品种体细胞胚胎发生和植株再生比较研究

选用我国长江和黄河流域棉区各10个棉花品种以及珂字201和YZ1共22个基因型,研究和优化棉花体细胞胚胎发生的相关条件参数。在此基础上,比较了两生态区棉花品种的体细胞再生能力。结果表明, 在IBA+KT的激素组合下,多数基因型有较强再生能力;在愈伤组织诱导时期,铵态氮是必需的,而在愈伤组织继代分化时期,一定浓度的硝态氮则能促进分化;没有铁盐不能诱导出愈伤组织,而铁盐浓度为56 mg L^-1时有利于胚分化;长江流域和黄河流域棉花品种的植株再生潜力没有明显差别,但长江流域的品种体细胞胚胎发生所需的时间长。本文首次获得了鄂抗棉3号、5号、鄂棉20、鄂棉23、豫棉9号、豫早73、豫棉12、豫棉1221等8个品种的体细胞胚胎发生和植株再生。     

Regeneration and transformation of cassava

A prerequisite for the development of a successful transformation system is the availability of efficient regeneration systems. Up to 1995 the only available regeneration system in cassava was an organized type of somatic embryogenesis. Transformation of these organized somatic embryogenic cultures with particle bombardment or Agrobacterium tumefaciens resulted in chimeric transformed embryos. However, the transformed sector was lost after repeated cycles of secondary somatic embryogenesis. After 1995 a less organized system of somatic embryogenesis was developed, so called friable embryogenic callus (FEC) and a system of adventitious shoot regeneration. The FEC regeneration system was combined successfully with particle bombardment. Selection of transgenic plants was based on either luciferase activity, or resistance to the aminoglycoside paromomycin or the herbicide phosphinothricin. Furthermore, protoplasts of FEC are able to regenerate into plants and can be transformed by electroporation. The adventitious shoot regeneration system was combined successfully with Agrobacterium tumefaciens. For this mature somatic embryos were cocultivated with Agrobacterium and cultured for adventitious shoot development. After selection based on the aminoglycoside geneticin or on hygromycin transgenic plants were formed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Plant regeneration in sweet potato (Ipomoea batatas L., Convolvulaceae)

The application of new techniques for improvement of sweet potato crops, particularly including the exploitation of somaclonal variation, gene transfer by genetic transformation and somatic hybridization, requires the control of plant regeneration from tissue cultures. Shoots can easily be regenerated from explants of stems, petioles, leaves and roots, while callus cultures do not produce any shoots. The potential of somatic embryogenesis and plant regeneration via embryogenesis was evaluated for 10 cultivars of sweet potato. Protocols for plant regeneration from cultured protoplasts have also been developed. Since mesophyll was resistant to enzyme digestion, fragments of stems and petioles, callus and cell suspensions were used as source of protoplasts of sweet potato. Series of transfers of protoplast-derived calluses, particularly those which had been obtained from in vitro plants, to media containing a high level of zeatin resulted in successful formation of shoots in only two sweet potato cultivars. In addition, the embryogenic potential was irreversibly lost through protoplast culture, since protoplasts isolated from embryogenic cell suspensions developed into non-embryogenic callus. Consequently, an alternative protocol is being successfully developed to improve plant regeneration from cultured protoplasts of sweet potato, involving first root formation from which shoots can then be regenerated. Preliminary evaluation in field conditions in Gabon revealed that plants regenerated from cultured protoplasts exhibited a great genetic variability in their growth and tuber formation in particular. This revised version was published online in July 2006 with corrections to the Cover Date.