Biotechnology in ornamental horticulture

Summary Genetic engineering techniques have so far had limited impact in the field of ornamental horticulture. As outlined in this review, transformation systems and potential genes of interest are available. As the development of new, novel varieties is an important driving force in the industry, there are, therefore, good prospects for the development of genetically modified ornamental variaties. The few products in the market to date may simply be a reflection of the relatively small scale of the industry compared to the major food crops, and the wide diversity of species within it. Commercial issues attendant to the use of gene technology in ornamental plants need careful consideration. These include careful choice of crop and background variety, the international regulatory process and freedom to operate.     

Cotton Biotechnology

Genetically modified (GM) cotton altered for insect and herbicide resistance released into commercial production in 1996 to 1997 now accounts for the lion's share of cotton acreage in the U.S. The rapid increase in transgenic cotton acreage in such a short period of time attests to the overall success of agricultural biotechnology. Grower satisfaction with transgenic cotton is largely due to several significant benefits, such as lower production costs, streamlined yet flexible management, and a reduced impact on the environment. This review article provides an overview of what has been accomplished thus far, as well as what improved germplasm may lurk on the horizon. A critical assessment of the gene delivery systems in cotton and possible targets for improvement is presented. The performance of the first generation of transgenic cotton plants engineered for insect, disease, or herbicide resistance is evaluated from the perspective of the benefits, the limitations that impact field performance, and management strategies. A few traits that hold future promise for increasing fiber productivity, enhancing and/or increasing the novelty of cotton-based products for the consumer, and improving human health and well-being are presented. Above all, cotton biotechnology offers to greatly enhance breeding programs by introducing novel traits that have eluded more traditional plant improvement methods and therefore will likely play an increasingly important role in the genetic improvement of cotton.     

高效诱导甜菜再生植株的研究

研究了栽培甜菜(Beta vulgaris L.)4倍体品系405叶柄外植体的离体培养。成功地建立了一套高频率诱导再生芽的程序。外植体取自生长在改良MS(MSB)附加BA和NAA或者单加BA的培养基中。经过30d以上预培养后的幼苗叶柄,在MS附加BA 1．0mg／L或NAA0．3mg／L,Bal．0mg／L培养基上直接诱导再生芽,并发育成苗．诱导频率最高可达51．3％。在1／2MS(MS培养基大量元素减半)附加NAA0．5～1．0mg／L的培养基上诱导生根．这一程序为甜菜扩大繁殖和遗传转化提供了一个良好的试验系统。     

叶绿体基因工程：一种植物生物技术的新方法

以叶绿体转化为主的叶绿体基因工程,与传统的基因工程技术细胞核转化相比,在外源基因表达水平和转基因植物安全性等方面有明显的优势, 尤其是在控制转基因沉默和遗传稳定性方面,可以互补核转化带来的局限性。因此,叶绿体基因工程是一种很具有发展前景的植物转基因技术,并在未来工农业生物技术领域发挥重要作用。本文着重在叶绿体转化技术主要特点,应用领域及其未来的发展前景等方面进行了简单评述。     

观赏凤梨生物技术研究进展(综述)

综述近年来观赏凤梨植物的应用和基础研究进展,重点介绍观赏凤梨的组织培养与种质资源保存,简述其遗传转化和遗传标记的研究,并对目前研究中存在的问题及今后发展提出建议。     

Production of Regenerants in Sugar Beet

The experimental results are presented on production of plants-regenerants of the sugar beet (Beta vulgaris L.) via callus formation or direct organogenesis from the leaf tissues. The method of aseptic treatment was developed for the seeds with strong bacterial and fungal invasion. The regenerant plants were obtained in the presence of various concentrations of synthetic hormones, such as cytokinin (6-benzaminopurine) and auxin (naphthylacetic acid), and inhibitor of auxin transport in plants (2,3,5-triiodobenzoic acid). This combination of growth regulators made it possible to avoid callus formation. The genotype of initial plants affected the capacity for callus formation and regeneration. The temperature influenced rhizogenesis in regenerants.     

Forage and Turf Grass Biotechnology

Referee: Dr. Ian Ray, Plant Breeding and Genetics, Department of Agronomy & Horticulture, New Mexico State University, MSC 3Q, P.O. Box 30003, Las Cruces, NM 88003-8003 Forage and turf grasses are the backbone of sustainable agriculture and contribute extensively to the world economy. They play a major role in providing high quality and economical meat, milk, and fiber products and are important in soil conservation, environmental protection, and outdoor recreation. Conventional breeding contributed substantially to the genetic improvement of forage and turf grasses in the last century. The relatively new developments in genetic manipulation of these species open up opportunities for incorporating cellular and molecular techniques into grass improvement programs. For some commonly used forage and turf species, significant advances have been achieved in the following areas: (1) establishment of a tissue culture basis for the efficient regeneration of fertile and genetically stable plants, (2) generation of transgenic plants by biolistic transformation and direct gene transfer to protoplasts, (3) recovery of intergeneric somatic grass plants by protoplast fusion, (4) development of molecular markers for marker assisted selection, and (5) sequencing of expressed sequenced tags and the development of DNA array technologies for gene discovery. Although difficulties still exist in genetic manipulation of these recalcitrant monocot species, impressive progress has been made toward the generation of value-added novel grass germplasm incorporating traits such as improved forage quality. The joint efforts of molecular biologists and plant breeders make the available biotechnological methods a useful tool for accelerating forage and turf grass improvement.     

Advances in Transgenic Rice Biotechnology

Rice is the most amenable crop plant for genetic manipulation amongst monocots due to its small genome size, enriched genetic map, availability of entire genome sequence, and relative ease of transformation. Improvement in agronomic traits of rice is bound to affect a sizeable population since it is a primary source of sustenance. Recent advances like use of ‘clean gene’ technology or matrix attachment regions would help improve rice transformation. Function of several novel genes and their promoters has been analyzed in transgenic rice. Significant progress has been made in introducing traits like herbicide, biotic stress and abiotic stress tolerance. Attempts also have been made to enhance nutritional characteristics of the grain and yield. Identification of genes controlling growth and development can be used to modify plant architecture and heading period. Transgenic rice can serve as a biofactory for the production of molecules of pharmaceutical and industrial utility. The drive to apply transgenic rice for public good as well as commercial gains has fueled research to an all time high. Successful field trials and biosafety of transgenic rice have been reported. This would act as a catalyst for greater acceptance of genetically modified food crops. The lessons learnt from rice can be extended to other cereals thereby opening new opportunities and possibilities.     

Biotechnology of the Banana: A Review of Recent Progress

Abstract: A number of biotechnological tools have been developed which could help breeders to evolve new plant types to meet the demand of the food industry in the next century. Available techniques for the transfer of genes could significantly shorten the breeding procedures and overcome some of the agronomic and environmental problems which would otherwise not be possible through conventional methods. In vitro protocols have been standardized to allow commercially viable propagation of desired clones of Musa. An overview of the regeneration of banana by direct and indirect organogenesis, and somatic embryogenesis is presented in this article. In addition, the use of several other biotechnological techniques to enrich the genome of banana, such as selection of somaclonal variants, screening for various useful characteristics, cryopreservation, genetic transformation and molecular genetics are reviewed. In conclusion, the improvement of banana through modern biotechnology should help ensure food security by stabilizing production levels in sustainable cropping systems geared towards meeting domestic and export market demands.     

荔枝生物技术研究进展

综述了离体培养、有利基因的克隆及遗传转化等生物技术的三个方面在荔枝研究中的应用进展。已有研究者分别建立了花粉培养、叶片培养、幼胚培养等获得植株的再生体系,克隆了部分荔枝基因,建立了基因枪与根癌农杆菌转化体系。这些研究为荔枝生物技术育种提供了基础。     

中国水仙生物技术研究进展

中国水仙是我国传统名花,其栽培中一直存在三个问题:品种单一、繁殖速度有限、病毒积累严重。生物技术的发展为解决中国水仙目前存在的问题提供了新的途径,将成为中国水仙遗传改良、种质资源创新的重要手段。该文从四个方面综述了近年来中国水仙生物技术的研究进展:(1)离体培养;(2)基因工程;(3)离体突变体筛选;(4)分子标记。     

魔芋属植物组织培养与遗传转化研究进展

本文对近20年来魔芋生物技术研究取得的进展进行了系统的回顾分析。组织培养是当前魔芋生物技术研究的主要内容,魔芋离体植株再生以器官发生途径为主,包括不定芽和拟球茎两种途径,后者是当前研究的热点。利用组织培养进行有用突变体的筛选和种质资源的保存也取得了一些有价值的结果。以抗病和品质改良为目的的转基因技术取得了较快发展,如抗病基因和抗除草剂基因等已实现成功转化。此外,本文还分析了魔芋生物技术研究中存在的主要问题并提出了相应的对策。     

In situ embryo rescue for generation of wide intra‐ and interspecific hybrids of Panicum virgatum L.

Wide crosses have been used for decades as a method for transferring novel genetic material and traits in plant breeding. Historically, many products of wide crosses require tedious and inefficient surgical embryo rescue prior to embryo abortion to recover single plantlets. We have utilized transgenic switchgrass (Panicum virgatum L. cv Alamo) as a pollen donor in conjunction with antibiotic or herbicide selection for recovery of intra‐and interspecific F₁ crosses by using developing ovules from the female parent and selecting for embryogenic cultures derived from the in situ immature embryo. Using this approach, several intravarietial crosses were generated between transgenic Alamo and the switchgrass varieties Kanlow, Blackwell and Cave ‐ in ‐ Rock as well as an interspecific cross with Atlantic coastal panicgrass. This procedure selected F₁ embryogenic callus produced from the developing embryo contained within isolated immature ovules. Several clonal plants were successfully regenerated from each cross. Southern blot, PCR, phenotypic analyses and genomic analysis confirmed F₁ hybrids. Using genotyping‐by‐sequencing shows the hybridization of the recovered plants by determining the ratio of transgressive markers to total compared markers between parents and their potential offspring. The ratio of transgressive markers to total compared markers was significantly lower between parents and their predicted offspring than between parents and offspring unrelated to them. This approach provides the possibility to move useful transgenes into varieties that are recalcitrant to direct transformation which can be optionally segregated thus useful to create new hybrids, as well as recovery of wide crosses that are either difficult or impossible using traditional techniques.     

Bt基因甜菜叶绿体转化载体构建及毒蛋白表达

利用植物叶绿体基因组在进化中高度保守的特点,根据烟草、菠菜、水稻叶绿体基因组全序列资料设计合成引物,PCR扩增并克隆了甜菜叶绿体两个重要功能基因rbcL和atpB(GenBank登录号分别为DQ067450和DQ067451),并以其作为定点整合外源基因的同源重组片段,构建了Bt基因CryIAc甜菜叶绿体定点转化载体pSKARBt,酶切鉴定表明:所构建载体符合预期设计。对克隆菌菌体总蛋白进行了生物杀虫试验,结果表明:Bt基因CryIAc能够在叶绿体特异性启动子及终止子的调控下表达,并对二龄末甘蓝夜蛾有很强的毒杀作用。该载体构建对培育甜菜高抗虫品种具有重要应用价值。叶绿体转化及后续工作正在进行中。     

麦类作物小孢子培养与遗传转化研究进展

小孢子作为单个单倍体细胞,通过诱导培养能再生成纯合的二倍体植株,不仅为分子生物学、遗传学、形态发生学研究提供稳定的材料,也对小麦等作物的转基因研究提供新方向和新思路。本文主要介绍麦类作物小孢子培养的基本步骤及关键因素,简要介绍了以小孢子为材料进行小麦基因遗传转化的方法。     

早期转基因兔胚的培养及外源基因滞留的研究

用显微注射法导入外源Smtpgh基因的早期免胚进行体外培养,并用PCR技术对单个胚中的外源基因进行了检测,以探讨SMTPGH基因在早期免胚中的滞留情况。研究结果表明早期转基因免胚在Tcl99+10％Fcs培养液中有75％发育到囊胚期;其外源基因在8细胞期前没有丢失,随后有逐渐丢失的现象。到胚胎的发育后期,其外源基因的滞留率接近于整合率。     

In planta soybean transformation technologies developed in China: Procedure, confirmation and field performance

Summary Soybean is a recalcitrant species for in vitro manipulation. Chinese scientists developed two in planta non-tissue culture soybean transformation procedures: (1) via the “pollen-tube-pathway” to introduce exogenous genomic total DNA of Glycine gracilis, the seed of which consisted of 50% protein, and (2) “ovarian injection” with exogenous plasmid DNA containing atrazine-resistant gene. A high yield and high seed protein (45.44%) cultivar, ‘Heisheng 101’, resulted from the first method, and atrazine-resistant F₁, F₂, and F₃ plants were obtained from the second method. Both exogenous single-genic Mendelian traits and multi-genic quantitative traits were transferrable with these simple and inexpensive procedures. However, some controversy exists with the acceptance of these novo procedures; mainly because instead of the standard Southern blotting, the RAPD and dot blotting techniques were used in the molecular confirmation of the transgenic status in the reported studies. This mini-review is dedicated to the memory of the late Dr. Guang-chu Yin (1936–1994), former Head of the Soybean Research Institute of Heilongiang, Academy of Agricultural Science, Harbin, China. Dr. Yin led the advancement of soybean biotechnology in China and pioneered the soybean pollen-tube-pathway transformation.     

Protein and Genome Evolution in Mammalian Cells for Biotechnology Applications

Mutation and selection are the essential steps of evolution. Researchers have long used in vitro mutagenesis, expression, and selection techniques in laboratory bacteria and yeast cultures to evolve proteins with new properties, termed directed evolution. Unfortunately, the nature of mammalian cells makes applying these mutagenesis and whole-organism evolution techniques to mammalian protein expression systems laborious and time consuming. Mammalian evolution systems would be useful to test unique mammalian cell proteins and protein characteristics, such as complex glycosylation. Protein evolution in mammalian cells would allow for generation of novel diagnostic tools and designer polypeptides that can only be tested in a mammalian expression system. Recent advances have shown that mammalian cells of the immune system can be utilized to evolve transgenes during their natural mutagenesis processes, thus creating proteins with unique properties, such as fluorescence. On a more global level, researchers have shown that mutation systems that affect the entire genome of a mammalian cell can give rise to cells with unique phenotypes suitable for commercial processes. This review examines the advances in mammalian cell and protein evolution and the application of this work toward advances in commercial mammalian cell biotechnology.     

谷子茎尖体外遗传转化体系的建立与优化

以谷子(Seteria italica)豫谷一号为实验材料,建立了一套简便、稳定的体外茎尖遗传转化体系。通过根癌农杆菌(Agrobacterium tumefaciens)介导的茎尖转化法,对转化受体采取不同的处理方式,待拟转化株长到三叶期后进行PCR鉴定。探明了草丁膦(Basta)喷施处理用于谷子转基因幼苗筛选的最适...     

玉米花粉体外萌发方法改进及其对花粉介导转基因的作用

超声波处理花粉介导植物基因转化方法由山西省农业科学院生物技术研究中心发明, 已被国家知识产权局授予发明专利(专利号ZL 99121152.9)。在该专利的基础上, 针对玉米(Zea mays)花粉取样、保存和处理条件等因素对其体外萌发的影响进行深入研究, 提出了改进玉米花粉体外萌发实验的方法。研究结果表明, 在不同时期对开花的玉米进行花粉培养时所需蔗糖溶液的浓度不同; 确定了玉米花粉的保存时间、条件及其对超声波处理后花粉萌发率的影响, 以提高该转化方法中花粉的活力, 并进一步验证了该转基因方法的可靠性; 讨论了玉米花粉体外萌发的操作技巧和各因子的参数, 对提高花粉介导植物基因转化效率有一定的参考价值。