植物体细胞原生质体遗传转化研究

重点介绍了植物体细胞原生质体遗传转化的方法和当前已经取得的成果,同时提出了目前原生质体遗传转化中存在的问题,展望了今后的工作重点。植物原生质体遗传转化的方法主要有：PEG介导转化法、电击穿孔转化法、脂质体介导转化法、农杆菌共培养转化法等。     

原生质体融合获得柑桔种间体细胞杂种

粗柠檬(Citrus jambhiri Lush)叶肉原生质体与哈姆林甜橙(C.sinensis L.Osbeck)胚性悬浮细胞系原生质体经PEG诱导融合,培养7天时原生质体恢复分裂。再生的胚状体在含有GA_3的培养基中萌发出茎芽。茎芽经生根诱导成为完整植株。对首批再生的5棵植株进行染色体检查,结果表明,全为四倍体,2n=4x=36。淀粉胶电泳分析过氧化物酶同工酶,结果显示这5棵植株为体细咆杂种。粗柠檬和哈姆林甜橙在该位点上均为同质结合,基因型分别是MM和FF。体细胞杂种含有双亲的酶带,基因型为MMFF。杂种植株生长旺盛,根系发达,叶片及植株形态介于双亲之间。本文对其作为砧木品种的可能性等问题作了讨论。     

植物遗传转化中存在的问题及对策

自 1 98 4年转基因植物问世以来 ,经过 1 0多年的发展 ,转基因技术已在近 2 0 0种植物中获得成功[1] 。转基因植物在提高植物的农业和园艺价值 ,作为某些重要蛋白质和次生代谢产物的廉价生物反应器 ,以及研究基因在发育和其它生理生化过程与代谢途径中的作用等方面 ,均充当了核心角色。目前 ,科学家们研究的兴趣已不再停留在简单地将基因导入植物中。遗传转化研究更多地转向转化的高效性、可预测性、稳定性和安全性等方面。本文就目前植物遗传转化中存在的一些主要问题及对策作一些介绍并提出我们的看法。1　组织培养中的体细胞变异　　目前…     

麻类作物组织培养及遗传转化研究进展

概述了国内外红麻等麻类作物快速繁殖、花药培养、原生质体培养、体细胞胚发生、器官发生等几个方面的组织培养以及遗传转化的研究进展,并对存在的问题进行了讨论,提出了进一步研究的一些见解,以期为促进麻类组织培养及遗传转化研究提供科学依据。     

小麦遗传转化研究进展

小麦 (ＴｒｉｔｉｃｕｍａｓｅｔｉｕｍＬ)是世界上分布最广 ,种植面积最大的粮食作物之一 ,传统的小麦育种方法主要是利用远缘杂交技术来提高小麦品质和产量 ,然而有限的可利用的种质资源常常限制了育种工作的突破。基因工程技术的发展和应用 ,打破了物种间的界限 ,增加了小麦外源基因导入的途径和范围 ,对小麦育种有着深远意义。自 80年代以来 ,虽然许多植物包括重要农作物水稻和玉米的遗传转化工作发展得很快 ,但小麦近几年才取得成功。这主要是由于农杆菌宿主的限制以及小麦原生质体培养的艰难性制约了小麦遗传转化的发展。经过多年的不…     

向日葵遗传转化研究进展

综述了PEG、基因枪和农杆菌介导的转化方法应用于向日葵遗传转化研究所取得的进展,并对影响向日葵遗传转化效率的因素和研究前景进行了探讨。     

水稻遗传转化研究进展

水稻遗传转化的主要方法,包括农杆菌介导法,基因枪法,电激法,PEG法等,论述了用于水稻转化的各种外植体,影响水稻遗传转化和植株分化的各种因素,各种标记基因及相应的选择方法和外源基因在转基因水稻中的遗传规律,比较了常用启动子在水稻中的表达强度,一些已转移到优良水稻品种中的有益农艺性状基因,如抗病、抗虫、抗除草剂等,介绍了它们在水稻品种改良中所发挥的作用。     

草莓遗传转化研究进展

草莓是一种重要的小型浆果,近年来育出很多优良品种,种植面积逐渐扩大.然而仍有很多因素限制了草莓生产的发展.基因工程技术为植物育种、种质资源开发利用等领域开辟了新的途径,可以获得常规育种难以或无法得到的新类型.本文综述了近年来国内外在草莓抗病虫、抗逆、抗除草剂、品质特性、耐贮运性等基因工程的研究进展以及基因型、试管苗生理状态、共培养时间、侵染时间和菌液浓度、抗生素等因素对草莓遗传转化的影响.对草莓转基因研究中存在的主要问题和今后的研究方向及应用前景进行了探讨.     

抗真菌植物基因工程的策略和进展

所有高等植物都受多种真菌的侵害,水稻的240多种病害中真菌性痫害占90％。,可见真菌病害是世界范围内危害作物产蘑的主要因素之一,是长期以来作物育种学家一直在努力攻克的难题。目前国     

丝状真菌遗传转化系统研究进展

丝状真菌是自然界中普遍存在的 ,并具有重要经济价值的一类真核微生物。近年来 ,对其分子生物学的研究取得了长足进展。本文对丝状真菌遗传转化系统的最新研究进展进行了综述 ,主要包括以下几个方面 :转化方法、载体、选择性标记、整合机制以及转化在丝状真菌研究中的应用。     

5′-Anchored simple-sequence repeat primers are useful for analysing potato somatic hybrids

Somatic hybrids between Solanum tuberosum cv 'Brodick' and S. sanctae-rosae were selected for having elevated chromosome numbers, intermediate morphology and potato cyst nematode resistance (derived from S. sanctae-rosae). DNA was extracted from this material and subjected to inter-SSR PCR directed by oligonucleotide primers comprising 5′-anchored di- and tri-nucleotide repeat motifs. PCR products were separated by polyacrylamide gel electrophoresis and visualised by silver staining. An average of 30.31 bands per primer were generated in each parent and, on average, 8.19 of these bands were polymorphic. S. sanctae-rosae-specific bands were observed in the hybrid material as was evidence of deletions, substitutions and rearrangements. The relative merits of this technique for the analysis of somatic hybrid material are discussed. Received: 23 July 1996 / Revision received: 22 October 1996 / Accepted: 22 March 1999     

Characterization of a partial male fertility derived from Ogura-cms in progeny of a resynthesized Brassica napus

Summary The inheritance of a partial male fertile phenotype in somatic hybrid B. napus plants that carried novel mtDNA was investigated over five backcross generations to B. napus Triton. The recurrent parent and the original somatic hybrid both contained chloroplasts resistant to atrazine. The F₁ population contained mainly plants that were partial fertile, and some of the plants differed in mtDNA. The partial fertility predominated in the progeny of each backcross generation, but fully male sterile and fertile plants were also obtained. However, the sterility/fertility of these latter plants was not stable; both the fully male sterile and the male fertile plants produced progeny that were again predominantly partial male fertile. This pattern of predominant partial fertility but occasional sterile and fertile plants persisted in different nuclear backgrounds. Neither the male sterility nor the male fertility could be fixed and made stable. Test crosses indicated that restorer genes were probably not associated with appearance of male fertile plants. The evidence indicates that the behavior of the partial male fertility is cytoplasmic, and probably controlled by the chondriome.     

甘薯胚胎及果实发育的研究

本文研究甘薯的胚胎发育及果实的形成。授粉后10—30分钟花粉粒在柱头上萌发,2小时花粉管抵达珠孔,5—12小时左右完成双受精。授粉后12小时胚乳核开始第一次有丝分裂;15小时合子开始第一次有丝分裂,18小时形成顶细胞和基细胞;尔后分化成原胚,球形胚,心形胚,鱼雷形胚,成熟胚。在适宜温度下21天左右胚胎发育完成。果为蒴果,其内含有1—4粒种子。授粉后3—4天子房开始膨大形成果实,21—30天蒴果与种子成熟。     

金色链霉菌转化系统的优化

12 %的蔗糖浓度、 0 5 %甘氨酸、溶菌酶酶解 1h,是金色链霉菌原生质体制备的较优条件。采用麸皮再生培养基替代R2YE再生培养基 ,原生质体再生率、生长及筛选效果得到明显改善。P buffer介导的质粒转化效率高于T buffer,33%的PEG1 0 0 0是质粒转化金色链霉菌原生质的最适浓度。     

Comparison of Nicotiana tabacum and Nicotiana nesophila hybrids produced by ovule culture and protoplast fusion

Summary Somatic hybrids were produced between Nicotiana tabacum and N. nesophila, two species incapable of conventional sexual hybridization. Sexual hybrids, though, could be produced between these two species by using ovule culture only when N. nesophila was female. Clones of somatic hybrids were compared with sexual hybrids. Statistically significant variation was observed between clones, but not between sexual hybrids, for pollen viability, flower morphology, leaf morphology, and trichome density. As all clones of somatic hybrids have 96 chromosomes, the variability could not be explained by interclonal variation in chromosome number. Variation between somatic hybrids could be the result of cytoplasmic segregation or recombination, mitotic recombination or small chromosomal rearrangements prior to plant regeneration. Variation between clones could be exploited as these interspecies hybrids are now being used to incorporate disease resistance into cultivated tobacco.     

Production of potato intraspecific somatic hybrids with improved tolerance to PVY and Pythium aphanidermatum

Somatic hybridization can be an interesting alternative for the selection of heterozygous and vigorous potato plants through combination of dihaploid genomes. The resulting hybrids can harbour interesting characters and thus can be used in agriculture if they are in agreement with agronomic criteria.

In this report, we used an intraspecific somatic hybridization technique for the production of tetraploid potato lines. Two parental combinations were used in protoplast electrofusion procedure: Aminca-Cardinal and Cardinal-Nicola. The selection of somatic hybrids was based on in vitro plant vigour. Therefore, among the 75 regenerated plants obtained from Aminca-Cardinal fusion, 3 putative hybrids were retained and 2 plant lines were selected among the 54 regenerated from the Cardinal-Nicola fusion. Heterosis was observed in the larger hybrid tuber size compared to the parents’. Our results also showed a precocity in the in vitro tuberization for the hybrids. Moreover, all of the regenerated putative hybrids were tetraploid (2n=4x=48 chromosomes). Isocitrate dehydrogenase and malate dehydrogenase isoenzyme analyses confirmed the hybrid nature of these lines. A molecular characterization performed by PCR amplification of simple sequence repeats and inter-simple sequence repeats confirmed that all these lines were somatic hybrids.

The effect of potato virus Y infection on these hybrid lines was tested by mechanical inoculation of plants cultivated in a greenhouse. The majority displayed a reduction of infection rate associated with a delayed appearance of symptoms compared to the parents. Moreover, complete resistance was noted for one hybrid line (CN2). All hybrids also showed improved tolerance to Pythium aphanidermatum infection during tuber storage or after plant inoculation.     

曲霉种间原生质体融合子生物学性状研究

对曲霉亲株及其各种融合子的普通遗传性状作了比较研究。这些性状包括：孢子大小、孢子DNA含量、孢子红外光谱吸收特征、菌株营养体分泌产物的紫外吸收特征等。发现这些指标尤其是孢子红外光谱吸收特征能够反应曲霉各菌株之间的遗传基础的差异。     

GENETIC TRANSFORMATION OF THE DIATOMS CYCLOTELLA CRYPTICA AND NAVICULA SAPROPHILA

Two species of diatoms were genetically transformed by introducing plasmid vectors containing the Escherichia coli neomycin phosphotransferase II (npt II ) gene. Expression of the bacterial npt II gene in the diatoms was achieved using the putative promoter and terminator sequences from the acetyl-CoA carboxylase gene from the centric diatom Cyclotella cryptica T13L Reimann, Lewin, and Guillard. The vectors were introduced into C. cryptica and the pennate diatom Navicula saprophila NAVIC1 Lange-Bertalot and Bonik by microprojectile bombardment. Putative transformants were selected based on their ability to grow in the presence of the antibiotic G418, and production of the neomycin phosphotransferase protein by the transformed cells was confirmed by western blotting. The foreign DNA integrated into one or more random sites within the genome of the transformed algal cells, often in the form of tandem repeats. This is the first report of reproducible, stable genetic transformation of a chlorophyll c -containing alga .