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1.
钝叶苔属(Cladopodiella)隶属于苔类植物的大萼苔科(Cephaloziaceae),本属有2种:C.fluitans(Nees)Spr.和C.francisci(Hook.)Buch.,广泛分布于欧洲和北美洲,其中前者在日本有记录。本属我国首次记录,仅发现1种:C.francisci(Hook.)Buch.,分布西藏。钝叶苔属CladopodiellaBuch.,Mem.Soc.F.Fl.Fennica5:87,1927.Type:Cladopodiellafluitans(Nees)Spr.植物体纤细,淡绿色。茎具腹面分枝,横切…  相似文献   

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采用“外类群对比准则”的性状分析方法,对我国特有植物四棱草属Sohnabelia及其近缘属筋骨草属Ajuga,香科科属Teucrium(唇形科Labiatae)和莸属Caryopteris,大青属Clerodendrun(马鞭草科Verbenaceae)等5属6种主要植物叶进行比较研究,结果表明;叶形卵圆形或椭圆形;叶缘均具齿,叶脉同为羽状脉;三级脉为分枝型和贯串型;边缘末级脉均为不完全型:齿型为  相似文献   

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四棱草属及其近缘属筋骨草属Ajuga,香科科属Teucrium(唇形科Labiatae),莸属Caryopteris,大青属Clerodendrum(马鞭草科Verbernaceae)5属,6种代表植物的叶表皮细胞形状、气孔类型和毛状体类型的比较研究结果是:(1)叶上表皮细胞形养 深小纹状不规则形,浅波纹状不规则形和浅波纹状四边形;(2)气孔类型是不规则型,平列型,横列型和等位模列型。(3)毛状体  相似文献   

4.
三花莸挥发油化学成分的研究   总被引:1,自引:0,他引:1  
周印锁  李兆琳 《植物研究》1993,13(4):394-398
用自制的水蒸气蒸馏-溶液萃取装置从马鞭草科莸属Caryopteris Bunge植物三花莸C.terniflora Maxim.中提取挥发油,含量为1.003%,用毛细管气相色谱-质普法对其挥发油的化学成分进行了研究,含量为分离出50多个组分,质谱鉴定了25个成分,占总色谱峰面积的63.78%。三花莸挥发油 的主要组分为α-柠檬烯(37.40%),(+)-顺-桧醇(26.90%),还含有α-蒎烯,  相似文献   

5.
复边藓属 (Cinclidotus)植物为水湿生藓类 ,其中文名是指叶片边缘有多层细胞构成厚边之意。该属植物多生于山区的流水中 ,附着于石上或树基部。本属全世界有 9种 (Wijk ,195 9;Crosby等 ,1992 ;Crosby等 ,1999) ,分布于南北半球的温带及暖热地区 (陈邦杰等 ,1963)。由于该属植物形态特征和生境条件较为特殊 ,苔藓学界对其系统位置一直有不同的看法和处理。我国复边藓属植物记录仅 1种 ,即Cinclidotusfontinaloides (Hedw )P Beauv ,产西藏喜玛拉雅地区(Mitten ,185 9)…  相似文献   

6.
短穗竹属植物的生态地理分布、生物学特性及其保护   总被引:1,自引:1,他引:0  
短穗竹属 (BrachystachyumKeng)隶属禾本科竹亚科 ,是我国亚热带东部地区特有的单种属 ,含 1种 1变种 ,即短穗竹〔B .densiflorum (Rendle)Keng〕和毛环短穗竹 (B .densiflorumvar.villosumS .L .Chene  相似文献   

7.
七子花的细胞学研究   总被引:8,自引:0,他引:8  
七子花HeptacodiummiconioidesRehd .是我国特有单种属植物 ,属于忍冬科北极花族TribeLinnaeeaeDumortier,主要分布于浙江、湖北两省 (徐炳声 ,1 988)。关于忍冬科的细胞学研究见诸报端的已有不少如 :六道木属的糯米条AbelliachinensisR .Br.2n =32 (Benko -Iseppon ,1 992 )、北极花属的北极花LinnaeaborealisLinn .2n =32 (Benko -Iseppon ,1 992 ;Semerenko ,1 990 )、忍冬属的Loniceraalpig…  相似文献   

8.
萼翅藤的核型研究   总被引:3,自引:0,他引:3  
使君子科 (Combretaceae)的萼翅藤属 (CalycopterisLam .)是一个亚洲热带山地特有属。《FloraofBritishIndia》记载有萼翅藤 (C floribunda)和C nutans两种 (Clarke ,1878) ,而Cooke (190 1)、徐廷志(1984 )和Mabberley (1997)认为是一个单种属 ,只有萼翅藤 1种。萼翅藤主要分布于缅甸、印度、新加坡和中国 ,中国仅见于云南西部的盈江县那邦坝。萼翅藤在中国植物区系研究上具有一定的价值 ,其在中国云南西部分布的事实有力地说明该地区植物区系的热带…  相似文献   

9.
Genomics ,Proteomics&Bioinformatics (GPB)issponsoredbytheBeijingGenomicsInstitute (BGI) ,theInsti tuteofGeneticsandDevelopmentalBiologyinChineseAcademyofSciences (CAS) ,andtheGeneticsSocietyofChina ,andpublishedbytheSciencePress ,Beijing .Thefirstissueofthisqua…  相似文献   

10.
苏云金芽孢杆菌的电穿孔及其工程菌的构建   总被引:1,自引:0,他引:1  
本文对苏芸金芽孢杆菌 (Bacillusthuringiensis,Bt)和蜡状芽孢杆菌 (Bacilluscereus,Bc)等部分菌株的电穿孔转化进行了研究 ,主要从电穿孔的供体质粒和受体菌株等方面讨论了各种因素对该方法的影响。同时利用电穿孔方法对部分Bt的高效野生株进行遗传改良 ,希望获得含有cry1Ac和cry1C高效基因组合的对鳞翅目棉铃虫、甜菜夜蛾都有效的广谱工程株。利用质粒 pSB1 40 2 (cry1C) ,pAMY(cry1Ac) ,pNQ1 2 2 (Cmr)对所有的供试菌株进行电穿孔转化 ,不同菌株表现出不同的转…  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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17.
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

18.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

19.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

20.
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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