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主要农作物转基因研究现状和展望 总被引：12，自引：0，他引：12
近15年来,大豆、水稻、玉米、小麦等主要农作物转基因研究取得了较大进展,几乎各种遗传转化方法在这些作物上都取得了成功,尤其是农杆菌介导法,不仅在难转化的双子叶作物大豆上取得了成功,而且在单子叶作物水稻、玉米、小麦上先后取得了突破。同时,将一些与重要性状改良有关的外源基因转入了主要农作物,包括抗虫、抗病、抗除草剂、抗逆、品质改良、发育调控、营养吸收等。转基因大豆、玉米、棉花、油菜在生产上得到了大面积种植,产生了极大的经济效益,2004年全球转基因作物的种植面积达到了8100万公顷。本文对大豆、玉米、水稻和小麦等主要农作物转基因研究历史和产业化现状进行了综述,并对主要农作物转基因研究中存在的问题进行了分析。 相似文献
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利用转基因植物生产口服疫苗的研究现状 总被引：15，自引：0，他引：15
本文概述了利用转基因植物生产口服疫苗的研究现状,分别对转基因植物生产口服疫苗的优点、作用原理,研究方法,已研究的口服疫苗及问题和前景进行了介绍。 相似文献
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刘秀梵 《中国生物工程杂志》1990,10(3):1-3
自1987年美国农业部地区家禽研究所(USDA,ARS,Regional Poultry Research Laboratory)成功地得到转基因鸡以来,有关研究已引起学术界和产业界的浓厚兴趣。今年6月25日至6月28日在美国康乃尔大学召开的第二届动物遗传工程国际学术讨论会上提交大会交流的20篇论文中,转基因鸡及有关研究就占了6篇。与其他转基因动物的研究相比较,转基因鸡的研究有其重要意义。 相似文献
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代谢转基因植物的研究现状与展望 总被引：1，自引：0，他引：1
代谢转基因是通过基因工程技术对细胞内的代谢途径进行遗传修饰,进而完成细胞特性改造。代谢修饰转基因植物是一个极具商业前景的领域,在医药、环境、农业等方面已有许多成功应用的实例。综合调控代谢的基因工程策略,讨论了代谢转基因植物的研究现状,我国农业生产中存在的主要问题和代谢转基因技术对我国农业发展的意义和前景。 相似文献
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以含绿色荧光蛋白（GFP）基因的质粒pSK100-DS、含切割对虾杆状病毒基因的核酶Rz1的质粒pRGRzl、含核酶Rz2的质粒pRGRz2和转基因空质粒pcDNA3为基础,把绿色荧光蛋白GFP基因克隆于pcDNA3的SV40启动了下面,由SV40启动子控制,含四个两种核酸基因的四联体克隆于pcDNA3的多克隆位点区,由T7启动子控制,构建成含两个Rz1、两个Rz2和GFP基因的转基因质粒pGTR,以用于转基因抗病毒对虾的研究。 相似文献
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对虾病毒病研究现状 总被引：1，自引：0，他引：1
对虾病毒病已严重危害世界对虾养殖业的发展,引起国内外学者的广泛关注。对近几年来对虾病毒病的研究现状和动态进行了概述,重点介绍了杆状病毒科(Baculoviridae)、细小病毒科(Parvoviridae)、呼肠孤病毒科(Reoviridae)、虹彩病毒科(Iridoviridae)、小RNA病毒科(Picornaviridae)、弹状病毒科(Rhabdoviridae)、被膜病毒科(Togaviridae)等几个科15种对虾病毒的特征、临床症状、病理特征、宿主范围和主要检测方法;对病毒病的传播途径、防治措施和存在的问题也进行了简要介绍。 相似文献
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Bt杀虫剂研究进展 总被引：3，自引：0，他引：3
张玲 《中国生物工程杂志》2005,25(B04):91-94
概述了害虫对转苏云金杆菌（Bacillusthuringiensis,简称Bt）抗虫基因植物的行为学反应、Bt毒素基因的鉴定和定位、Bt辅助蛋白、昆虫对Bt毒素的抗性机理、天敌与转Bt基因抗虫植物的协同控害作用、Bt安全性方面的研究现状,提出了今后的研究方向。 相似文献
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Li C.-J.Yao X.Nan Z.-B. 《植物生态学报》2018,(8):793-805
Research on drunken horse grass (Achnatherum inebrians)-endophytic fungi (Epichloë gansuensis, E. inebrians) represented an important area of endophyte research in China. Compared with tall fescue (Festuca arundinacea)-endophyte (E. coenophiala) in the United States and perennial ryegrass (Lolium perenne)-endophyte (E. festucae var. lolii) in New Zealand, A. inebrians-endophyte research in China is becoming a leading branch of endophyte research. The studies of A. inebrians-endophyte symbionts over the past three decades were reviewed, mainly including endophyte distribution, detection methods, infection rate, fungal diversity, stress tolerances of drought, cold, salt, heavy metal, pest, disease and their mechanisms, secondary metabolite of alkaloids, feeding experiments and its ecological functions etc. Research reveals that drunken horse grass itself has no toxicity, the grazed animals will be intoxicated if the grass bears infection by Epichloë endophytes and produces ergot alkaloids. Future research will focus on E. gansuensis and E. inebrians genomics and endophyte functions. In other research we will create new grass cultivars that are 1) sanitized of the endophyte and non-toxic, 2) utilizing novel endophytes that deter birds feeding and 3) utilizing endophytes that are modified to produce novel fungicides, pesticides or medicines. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved. 相似文献
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Summary . We consider methods for estimating the effect of a covariate on a disease onset distribution when the observed data structure consists of right-censored data on diagnosis times and current status data on onset times amongst individuals who have not yet been diagnosed. Dunson and Baird (2001, Biometrics 57, 306–403) approached this problem using maximum likelihood, under the assumption that the ratio of the diagnosis and onset distributions is monotonic nondecreasing. As an alternative, we propose a two-step estimator, an extension of the approach of van der Laan, Jewell, and Petersen (1997, Biometrika 84, 539–554) in the single sample setting, which is computationally much simpler and requires no assumptions on this ratio. A simulation study is performed comparing estimates obtained from these two approaches, as well as that from a standard current status analysis that ignores diagnosis data. Results indicate that the Dunson and Baird estimator outperforms the two-step estimator when the monotonicity assumption holds, but the reverse is true when the assumption fails. The simple current status estimator loses only a small amount of precision in comparison to the two-step procedure but requires monitoring time information for all individuals. In the data that motivated this work, a study of uterine fibroids and chemical exposure to dioxin, the monotonicity assumption is seen to fail. Here, the two-step and current status estimators both show no significant association between the level of dioxin exposure and the hazard for onset of uterine fibroids; the two-step estimator of the relative hazard associated with increasing levels of exposure has the least estimated variance amongst the three estimators considered. 相似文献
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黑长臂猿的分布、现状与保护 总被引：10，自引：0，他引：10
黑长臂猿 (Hylobates concolor)是现生 1 1种长臂猿中其系统地位最低的灵长类。历史时期长臂猿曾广泛分布在我国南部的大部省区。自公元 4世纪以来 ,它们的分布发生了很大变化。分布区从北到南 ,从东到西急剧缩小 ,现黑长臂猿缩小到只在海南岛、云南南部和越南北部 ,已分化为 6个亚种。分布于我国的 5亚种中 ,海南亚种 (H . c. hainanus)现今仅20余只 ,是最濒危的一个亚种 ;.北部湾亚种 (H.c.nasutus) 50年代曾在广西西南部发现 ,60 -70年代已绝迹 ;指名亚种 (H.c.concolor)主要分布于越南北部、滇南和滇中哀牢山。滇南约有100余只 ,滇中哀牢山可能有40 - 60群 ,180 - 240只 ;景东亚种 (H . c. jingdongensis)为滇中无量山的特有亚种 ,现有100 - 116群 ,430 - 500只 ;滇西亚种 (H . c. furvogaster) ,只分布在滇西南的沧源、镇康、云县和耿马等地 ,约有 2 6-42群 ,100 - 150只。现今 ,黑长臂猿的分布区已不足1000Km2 ,总数量约1000只 ,为高度濒危的灵长类动物。造成黑长臂猿濒危的主要原因是 :热带和南亚热带原始森林的被破坏和缩小、人类活动的干扰使生境破碎和恶化、过度猎捕和长臂猿自身的生物学弱点。目前 ,中国的黑长臂猿已在 9个自然保护区中得到保护。 相似文献
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Wang Yingxiang 《人类学学报》2000,19(02):138
Black-crested gibbon ( Hylobates concolor) , an earliest distinct taxon in phylogeny and a more endangered species among 11 extant species o f gibbon, is now mainly distributed in South of China and North of Vietnam. Althouth its historic distribution was widely extended to Taiwan, Fujian in the East, to Yunnan in the west, to Qinling in the North and to the Island Hainan in Southeastern and Southern China, they are now only found in Hainan Island, south and middle of Yunnan, China and northern Vietnam, the total distribution area is less than 1 000 km2 . This species totaled about 1 000 individuals. Taxonomically , extant black gibbons can be divided into six subspecies, five of them distribute in China. ( 1) H. c. hainanus distributed in 12 counties to the south of \" Nada- Tunchang-Qio nghai\", Hainan Island with no less than 2000 individuals before 1950s, but in 1980s only about 15 individuals of 4 groups live in Bawanlin Nature Reserve, it is the most endangered subspecies in concolor gibbon; ( 2) H. c. nasutus was discovered in southwest of Guangxi in 1950s, but disappeared in 1960s- 1970s, the living animals could be found in northeastern Vietnam, and are estimated less than 50 individuals; ( 3) H. c. concolor, this subspecies is mainly distributed in Northern Vietnam and south Yunnan, it was once widely distributed in south and southeast Yunnan, now its distribution is restricted to Luchun, Jinping , Hekou and Pingbian in South Yunnan with about 100 individuals and to North Vietnam ( probably no mo re than 50 animals) , and M t. Ailao, middle part of Yunnan ( about 180- 240 individuals belonging to 40- 60 groups); ( 4) H. c. jingdongensis, it is only distributed in M t. Wuliang , middle of Yunnan, and it is estimated to include about 300- 400 animals ; ( 5) H. c. furvogaster, it is only found in Chang yuan, Zheng kang, Yunxian and Gengma, southwest of Yunnan, and about 30- 50 animals belonging to 10- 15 groups are left. So far, black gibbons in China are protected in 9 nature reserves, among which Bawanglin Nature Reserve and Wuliang Nature Reserve are national and provincial reserves respectively and aim at mainly to protect black gibbons. After more than ten years protection and management, the shrinkage of distribution area and decrease in number of this animal have been stopped, and the status is maintained in the level of middle 1980s. 相似文献
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邱新棉 《植物遗传资源学报》2004,5(3):247-251
本文在简要回顾植物空间诱变育种历史的基础上,论述了植物空间诱变育种的机理,植物在高真空、微重力、强辐射、交变磁场及其他因素的综合作用下产生变异和植物空间诱变育种效应以及突变性状的遗传;全面综述了空间诱变育种在中国作物新品种、特异优良种质材料的创新中取得的成就.最后对未来植物空间诱变育种的应用前景进行了展望,并指出空间诱变技术开创了植物育种的又一新途径. 相似文献
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The yak (Bos grunniens) is a long-haired bovid, endemic to the Tibetan Plateau and the adjacent high-altitude regions. The domesticated subspecies of yak (B. grunniens grunniens) are abundant and closely associated with the livelihoods of herders, while the wild subspecies of yak (B. grunniens mutus) are endangered due primarily to anthropogenic effects. The endangered status of wild yaks calls for consideration, if we are to secure its long term survival, hence this study. Here we hope to provide baseline information necessary for further research and protection of the wild yak resources. We use published data to discuss their evolution, their characteristics as well as their distribution in the Tibetan Plateau and the adjacent high-altitude regions. We were able to come up with a world wild yak distribution map, which may be useful for establishing protected areas, as well as updating the species IUCN Red List Status. From the data available, we were also able to provide an estimate of the wild yak population in China (∼22,000 wild yaks living in China), corresponding to 90% of the total world population. We further discuss the major threats to yaks, and we give some suggestions for future and sustainable conservation. 相似文献
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1998年和1999年对云南省野生稻原生境进行考察,并结合云南野生稻的历史,阐述了云南野生稻的保护保存现状,云南野生稻原生境正在遭到严重的破坏,野生稻群体锐减,云南野生稻保护保存现状令人担忧.最后提出了保护保存云南野生稻资源的四点建议. 相似文献
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