转Bt-cry1Ab玉米花粉对意大利蜜蜂生长发育及体内酶活性的影响

自10年前首次种植转基因植物以来,转基因作物已在全球得到大面积推广。这些转基因作物中绝大多数品种具有抗虫基因能够增强作物对靶标昆虫的抗性。同时转抗虫基因植物可能带来的生态安全和环境问题也引起了国际社会广泛的关注。鉴于此,本实验开展了转Bt-cry1Ab基因抗虫玉米花粉     

提高外源基因在转基因植物中表达效率的途径

利用转基因技术获得具有目的性状的转基因植株,是进行作物品种改良的有效方式.但基因沉默等现象降低了外源基因在转基因植物中的表达效率.从外源基因的DNA修饰水平、翻译后蛋白的定位、以及转基因方式等方面综述了国内外植物基因工程中的相关研究;分析了外源基因表达效率低的原因;提出了克服基因沉默并实现外源基因高效表达的途径.     

通过转基因手段改善作物产量性状

在世界范围内,目前的作物转基因研究主要针对于提高作物自身的抗逆性开展,而产量是一个较为复杂的农艺性状,受多种基因与环境的相互作用所控制.其中,光合作用、氮素同化、碳源分配、植株株型等生理过程是产量形成的基础.随着植物基因组测序工程的逐渐完善,控制上述生理过程的许多基因已被成功分离,并通过基因工程手段对其进行遗传修饰,最终获得了产量性状得以明显改善的转基因植物.虽然目前对于基因如何调控每个性状的机制尚未得到充分阐明,但是这些基因的获得及其增产功能的验证为作物的高产育种提供了一条全新的思路和一系列新方法.随着国家转基因生物新品种培育科技重大专项的实施,对功能基因的认识显得尤为重要,本文主要从影响作物产量形成的源、流、库、株型、氮素及水分利用率等几方面入手,对近10年来控制植物产量性状基因的相关研究进行了综述,期望为高产转基因作物新品种的培育提供一定的理论依据.     

转基因食品与食品安全

(一)中国市场上会出现带转基因标识的食 品吗 农业转基因生物,即利用基因工程技术改 变基因组构成,用于农业生产或者农产品加工 的植物、动物、微生物及其产品。目前,我国转 基因作物耕种面积已有100多万亩,继美国、阿 根廷、加拿大之后列第4位,但主要种植的是抗 病毒的烟草和抗虫棉。到目前为止,国内还没 有一例大宗转基因粮油作物获准进入商品化生 产,只有一些科研机构有小面积的转基因作物     

转Bt基因作物对丛枝菌根真菌的影响研究进展

在过去的十年里，世界范围内转基因作物尤其是抗虫性转Bt基因作物的品种和种植面积迅速增加。同时，转Bt基因作物的环境安全性评价问题成为人们关注和研究的热点。丛枝菌根真菌（AMF）是生态系统中普遍存在的土壤微生物，能与绝大多数植物种类形成共生关系，在农业生态系统中起重要作用。转Bt基因作物环境释放后，其与AMF问的共生关系是否受所转入Bt基因的影响，以及影响机制需要及时研究。为此，综述了转Bt基因作物与AMF共生特征方面的研究进展，并根据Bt毒素发生的空间和时间规律提出了危害机制以及转Bt基因植物的规模化种植将降低农田系统中的AMF的生物多样性的观点。     

转基因植物的生态安全性风险

转基因植物的应用在对农业生产带来重大变革的同时,其安全性风险备受关注。本文重点论述了转基因植物的生态安全性风险,即转基因植物的使用带来的直接或间接的生态影响,包括：目标害虫对转基因植物的抗性,转基因植物对非目标害虫的毒性及其对寄主嗜好性、有益生物及天敌的安全性、生物多样性及生态系统结构的影响;基因漂移及杂草化问题及应用转基因作物后植保费用的变更等。针对这些关键问题,定量风险评估和制定风险预防与治理策略具有重要意义。     

无抗性标记基因转基因植物研究进展

植物转基因研究中抗生素和除草剂抗性标记基因可以提高转化体的筛选效率。然而，对抗性标记基因潜在的生物安全性疑虑阻碍了植物转基因研究的发展和应用。解决抗性标记基因安全性问题的策略有标记回避和标记剔除两类，前者是在转化阶段不使用抗性标记基因或采用安全标记基因筛选转基因植株；后者则采用抗性标记基因筛选获得转化体后剔除标记基因。无抗性标记基因转基因植物不仅促进转基因技术的发展，而且缓解潜在的生物安全问题。     

中国转基因油菜的环境安全性分析

根据中国转基因油菜研究和环境释放的现状，对中国环境条件下转基因油菜的生存竞争能力、基因扩散风险以及对生物多样性影响等环境安全问题进行了分析。分析认为，中国是许多十字花科植物进化起源中心和生物多样性中心，生态环境类型复杂；转基因油菜的外源基因可以通过花粉向油菜（Brassica napus）、白菜（B．rapa）和芥菜（B．juncea）类植物扩散；中国转基因油菜的基因扩散风险高于其它作物．存中国，油菜的转基因技术相当成熟，油菜的转基因实验频次很高，涉及的基因种类繁多，进口的转基因油菜数量巨大，隐患不容忽视。在中国，转基因油菜的安全性管理和研究相当薄弱，检测和监测手段无法满足安全管理需求，这一现状必将阻碍中国转基困油菜的产业化进程，并对中国环境安全带来隐患。作者提出，加强转基因油菜的环境安全意识，加强中国转基冈油菜的安全管理及其措施的落实，加强转基因油菜检测和监测等技术平台的建设。     

植物抗寒性基因工程研究进展

导入外源基因提高植物抗逆性已成为现代植物育种主要手段 ,阐述了动物抗冻蛋白及其转基因植物、植物冷诱导基因、脂肪酸去饱和酶基因、SOD基因、脯氨酸基因、植物抗冻蛋白及其转基因植物抗寒性基因工程的研究进展。     

叶绿体转化及其应用于作物改良研究的最新进展

农杆菌介导的核基因转化技术已普遍应用于作物改良和分子育种方面,而其不可避免的转基因沉默现象和生物安全问题是科研工作者和广大民众关注的焦点,进而成为基因工程技术广泛应用的主要限制因素。叶绿体遗传转化技术因具有核转化不可比拟的独特优势,成为植物基因工程发展的新方向和科研工作者研究的热点之一,通过该技术有望培育出真正生物安全的转基因作物新品种。本文围绕叶绿体转化的原理、方法、筛选标记及其应用等方面进行阐述,着重介绍其在作物改良方面研究的最新进展,并对存在问题及应用前景进行了展望。     

QTL analysis reveals the genetic architecture of domestication traits in Crisphead lettuce

The genetic architecture of crop domestication is generally characterized by three trends: relatively few genomic regions with major QTL effects are involved, QTL are often clustered, and alleles derived from the crop do not always contribute to the crop phenotype. We have investigated the genetic architecture of lettuce using a recombinant inbred line population from a cross between a crop Lactuca sativa (‘Salinas’) and its wild relative L. serriola. Few genomic regions with major QTL, plus various intermediate QTL, largely control the transition from wild to cultivated Crisphead lettuce. Allelic effects of all major QTL were in the expected direction, but there were intermediate QTL where the crop contributed to the wild phenotype and vice versa. We found two main regions with clusters of QTL, one on linkage group 3, where the crop allele induced lower seed output, another on linkage group 7, where the crop allele caused a delay in flowering time. Potentially, knowledge of genetic changes due to the domestication could be relevant for the chance that a transgene inserted in a crop genome will spread to wild relatives due to hitchhiking effects. If a transgene would be inserted in one of these regions, background selection on the crop alleles may lead to a reduced fitness of hybrids with the transgene. QTL research on the effects of domestication genes can thus indicate regions in the crop genome that are less likely to introgress, although these still need to be verified under field conditions.     

Discovering Transgenic Elite Events: Using Information from Early Screening Trials for Improving Experimental Design

The transgenic improvement of a commercial crop requires a suitable transgene as well as a suitable insertion location in the crop’s genome. An elite event is a successful insertion of an active transgene, and many events need to be screened to detect such elite events. This is expensive, hence optimization is needed.     

植物耐铝机理研究进展

铝毒是酸性土壤上作物生产的主要限制因子,植物耐铝机理以及与耐铝有关基因的研究是近十多年来研究的热点。本文对植物耐铝的生理、遗传及分子机理的研究进展作了综述。明确了目前取得的突破性进展已使通过植物遗传育种及生物技术手段提高粮食作物耐铝性成为可能;同时,本文对今后的研究方向作了简要的讨论。     

作物分子生态学研究与展望

从分子水平研究作物与环境的关系及其作用规律已成为当代作物栽培学研究的重要内容,也是现代分子生态学的热点问题之一。作者从作物生长发育相关基因的遗传生态特性入手,着重分析在作物生长发育过程中的遗传分子生态特性与环境分子生态效应,在此基础上,提出应根据各作物各生长发育阶段相关基因的遗传生态特性,制定科学的调控技术,以实现作物高产、优质、高效、环境友好、安全的生产目的。并进一步阐述了当前作物分子生态学亟待解决的几个理论问题及主攻方向。     

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。     

The diversity and sustainable development of crop genetic resources in the Lancang River Valley

This paper reviews the status of crop genetic resources in Yunnan province of China from 1978 to 1999. Results are presented of same research in the field of the diversity of cultivated and wild crop. Yunnan is one of the centre of origin or genetic diversity of more than 200 cultivated and wild crops. There are over 500 cultivated plants which account for over 80% of the total in China and more than 650 species of wild crops. In addition, there are more than 440 species of main wild flowers. According to our recently researches there are abundant species, subspecies and varieties of crop genetic resources in Yunnan Province. The Lancang River Valley is the richest genetic diversity centre of rice, maize, wheat, barley, buckwheat, legumes, ramie, sugarcane, vegetable, tea, actinidia and so on. For example, there are 59 varieties (including all varieties of Oryza sativa L. in China) in 5933 accession of Yunnan indigenous rice. The Lancang River Valley is one of the centre for genetic diversity of rice resources and a rich region for elite and rare rice resources of Yunnan, too. In order to protect the highly endangered crop genetic resources in the Lancang River Valley, it is necessary and very important to set up a collection, conservation, utilization and research system, enhancing their protection and utilization, in situ- and ex situ-conservation, farm management and sustainable production.     

The use of genetic resources in crop improvement: Lessons from China

The use of crop genetic resources in improvement programmes should be the ultimate objective of all undertakings in the field of germplasm resources. The present situation and future direction of the use of crop germplasm in China was assessed from responses to a questionnaire distributed to 165 plant breeders and curators nationwide. The general opinions for the limiting factors of germplasm utilization were also evaluated. Responses from the questionnaire indicated that the use of germplasm in breeding programmes is much more important than the direct use of germplasm in crop production as cultivars released. Among different types of crop genetic resources, released varieties and breeding lines contribute more to crop breeding. Wild relatives and genetic stocks, however, are expected to play a greater role in the future. Landraces will remain important in improvement. Limited useful germplasm available to breeders is the basic reason for the insufficient use of germplasm in crop breeding at present. The complex reasons which affect the availability of useful germplasm involve the research level, links between breeder and curator and others. To counter these, we propose some suggestions and measures which can be implemented in the near future.     

Traditional Crop Diversity and its Conservation on-Farm for Sustainable Agricultural Production in Kumaon Himalaya of Uttaranchal State: A Case Study

Farming communities in traditional agroecosystems have been playing an important role in conserving agricultural diversity. They are not only the custodians but also managers of the crop diversity and maintain the dynamic processes of crop evolution and adaptation, the key elements of sustainable agricultural productions. The Himalayan highlands are important centres of crop plant diversity due to high ecological heterogeneity and high local socio-cultural integrations. The crop genetic diversity of Kumaon Himalaya in Uttarachal State of India has been documented in the present study. Existing crop genetic diversity at inter- and intra-species level was assessed and factors for changes in crop compositions and farming systems during the recent past were studied. Farmer management of rice landrace populations were studied in greater detail. Various benefit enhancing options for farmers from local crop diversity were scrutinized based on farmer perceptions and priorities for efficient management of local crop diversity on-farm and its sustainable utilization for agricultural production.     

作物种子胚乳中等位基因多态性表达

本文综述了作物种子胚乳中等位基因表达多态性的研究进展，介绍了基因组印记现象及其对作物种子胚乳性状的表观遗传及种子发育的影响。     

Genetic basis for folk classification of oca (<Emphasis Type="Italic">Oxalis tuberosa</Emphasis> Molina; Oxalidaceae): implications for research and conservation of clonally propagated crops

Clonally propagated crops exhibit great diversity and are integral components of global and regional food systems. At the same time, little is known about the mechanisms that generate diversity within clonal crop species, and this diversity is increasingly threatened by economic, environmental, and social change. Research addressing the genetic basis for folk classification of clonal crops can address both of these challenges. Here, we carry out such research through a case study of the Andean tuber crop, oca (Oxalis tuberosa Molina). We employ ethnobotanical and molecular genetic methods to assess the congruence in partitioning of 216 oca accessions with respect to 26 folk taxa and with respect to 31 genetic clones. We find that the greatest number of folk taxa (11) correspond to single, unique genetic clones, but we also identify two instances of single folk taxa comprising multiple genetic clones and two instances of multiple folk taxa comprising single, shared genetic clones. We discuss the potential roles of different diversity-generating mechanisms, such as somaclonal variation and sexual reproduction, underlying these varied forms of congruence in order to inspire more directed research on this topic. We also discuss the implications of our findings on in situ and ex situ conservation work, in which practitioners often approximate crop genetic diversity by counting folk taxa. Ultimately, we argue that efforts to understand and conserve clonal crop diversity will be most effective when both folk classification and its genetic basis are considered together.