Genetic transformation of loblolly pine using mature zygotic embryo explants by Agrobacterium tumefaciens

Introduction1Genetictransformationinconifershasthepotentialtoallowtheselectiveimprovementofindividualtraitsinelitecloneswhilestillmaintainingtheexistingcombinationofgenesresponsibleforthesuperiorphenotype(Charestetal.1991;Jamesetal.1996;Walteretal.1999).Atpresent,althoughconsiderableresearchefforthasbeendevotedtothegeneticengineeringofconiferspecies(Sederoffetal.1986;Bekkauoietal.1988,1990;Robertsonetal.1992;Bomminenietal.1993;Shinetal.1994;Klimaszewskaetal.1997),ithaslaggedbehindadvancesma…     

三相不平衡配电网的潮流计算

该文提出了一种适用于三相辐射状配电网潮流计算的方法。该方法根据辐射状配电网络的结构特点,在考虑了三相不平衡的情况下,建立了配电系统潮流的计算模型,算例结果证明了该算法具有输入格式简单、计算速度快、占用内存少和收敛性好等特点,从而验证了该算法的有效性。     

峨眉冷杉人工林合理经营密度表的编制

利用峨眉冷杉人工林主要分布区的209块标准地调查材料,以林木生长与营养空间相关的理论为基础,追求峨眉冷杉各生长期林分蓄积的最大年生长量为目标,编制了峨眉冷杉人工林合理经营密度表,为合理经营现有人工林提供了科学依据。     

Preliminary Studies on Establishment of Genetic Transformation System in Loblolly Pine

Introducti0nt,ollilcrsareec0n0l11icall}impo11a11tl0resttree\`orlLl-tvide.beingusedtbrs0iIc0nservatio11-el1vir()11111e11lprotectiol1,\`ood.prodtlctiOI1.andasavariet}ofhIIiId-ingandil1dLlstr}'Inaterial.ForcOI1itbrgel1cticiI11-provel11el1tplan-classicalbreed…     

我国种子植物物种丰富度空间分布格局的分析探讨

文章利用我国主要省(区)现有种子植物及空间、地形资料,通过通径分析和回归分析,发现中国种子植物物种丰富程度主要受纬度、土地面积、海拔幅度、山丘比(山地和丘陵面积占土地面积的比例)等因素影响,且呈现出一定的规律性:种子植物丰富度随纬度的增大而减小,随土地面积、海拔幅度、山丘比的增大而增大;物种密度随纬度和土地面积的增大而减小,随海拔幅度、山丘比的增大而增大。     

火炬松胚性愈伤组织诱导和植株再生的研究

火炬松胚性愈伤组织诱导和植株再生的研究唐巍欧阳藩（中国科学院化工冶金研究所生化工程国家重点实验室北京１０００８０）郭仲琛（中国科学院植物研究所北京１０００９３关键词火炬松,体细胞胚胎发生,植株再生本文于１９９６年１０月２８日收到。国家“８６３”资...     

微弹介导的火炬松遗传转化

本文建立了一个微弹介导的火炬松遗传转化系统。这个系统解决了火炬松遗传转化过程中存在的许多困难。运载抗虫基因的质粒载体经微弹转化法进入火炬松成熟合子胚,然后在添加了卡那霉素的培养基上从转化的成熟胚上诱导出有器官发生潜力的愈伤组织,再从转化的愈伤组织上产生转基因植株。利用这一系统生产的转基因植株已经被随机扩增技术、Southern杂交技术和虫试验所证实,并且转化的植株已在土壤中成活。图3表2参28。     

树脂生物合成的分子遗传新进展和增强针叶树防御的遗传工程策略

Since the first terpenoid synthase cDNA was obtained by the reverse genetic approach from grand fir, great pro-gress in the molecular genetics of terpenoid formation has been made with angiosperms and genes encoding a monoterpene synthase, a sesquiterpene synthase, and a diterpene synthase. Tree killing bark beetles and their vectored fungal pathogens are the most destructive agents of conifer forests worldwide. Conifers defend against attack by the constitutive and inducible production of oleoresin that accumulates at the wound site to kill invaders and both flush and seal the injury. Although toxic to the bark beetle and fungal pathogen, oleoresin also plays a central role in the chemical ecology of these boring insects. Re-cent advances in the molecular genetics of terpenoid biosynthesis provide evidence for the evolutionary origins of oleoresin and permit consideration of genetic engineering strategies to improve conifer defenses as a component of modern forest bio-technology. This review described enzymes of resin biosynthesis, structural feathers of genes genomic intron and exon or-ganization, pathway organization and evolution, resin production and accumulation, interactions between conifer and bark beetle, and engineering strategies to improve conifer defenses.     

为Quick BASIC和Turbo C语言扩充一组屏幕控制子程度和函数

为节省屏幕控制程序编制时间，对Quick BASIC4.5和Turbo C2.0系统扩充了屏幕输出、键盘输入、立体投影响窗口、屏幕保存与恢复、窗口清除等子程序和函数，用于在文本方式下屏幕控制的子程序或函数。