首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
本属与多种树种有菌根关系:如Pinus,Larix,Abies和Pseudotsuga,但在Larix林下,本菌往往与土壤中的鞣料相聚集,对周围某些植物根系不利。本属现知15种,本区6种。  相似文献   

2.
中国东北落叶松属植物rbcL 基因的序列分析及系统演化   总被引:2,自引:0,他引:2  
长白落叶松的分类位置及与兴安落叶松的种间关系, 长期以来未有定论。本研究从大兴安岭、小兴安岭及张广才岭等6 个地点采集实验材料, 对其叶绿体DNA 的rbcL 基因进行PCR-RFLP 分析并测序。结果显示它们的rbcL 基因序列均没有差异, 表明东北地区落叶松属植物有共同起源。在系统演化上, 长白落叶松来自兴安落叶松(Larix gmelinii Rupr.), 应作为兴安落叶松的变种即L.gmelinii Rupr.var.olgensis Ostenfeld et S.Larsen  相似文献   

3.
记述采自中国西北地区的突瓣叶蜂亚科1新种:西北槌缘叶蜂Pristiphora xibei sp.nov.,编制了古北区危害落叶松属植物的槌缘叶蜂属种类分种检索表。在宁夏地区,新种危害华北落叶松Larix gmelinii var.principisrupprechtii(Mayr.)Pilger,并与红环槌缘叶蜂(落叶松红腹叶蜂)Pristiphora erichsonii(Hartig,1837)混合发生,但种群数量显著小于后者。  相似文献   

4.
记述采自中国西北地区的突瓣叶蜂亚科1新种:西北槌缘叶蜂Pristiphora xibei sp,nov.,编制了古北区危害落叶松属植物的槌缘叶蜂属种类分种检索表.在宁夏地区,新种危害华北落叶松Larix gmelinii var.principisrupprechtii(Mayr.) Pilger,并与红环槌缘叶蜂(落叶松红腹叶蜂)Pristiphora erichhsonii (Hartig,1837)混合发生,但种群数量显著小于后者.  相似文献   

5.
贺新生 《菌物学报》2004,23(1):150-150
Panaeolina Maire, Meded. Proefstn W. Java, Kagok-tegal 15:109 [S閞.Bot.no.2] (1933) 疣孢斑褶菇属,模式种为:Panaeolina foenisecii (Pers.:Fr.) Maire。本属外观酷似Panaeolus,但斑褶菇属孢子光滑,本属孢子深紫褐色,孢子壁有明显疣状突起;也认为近似Psathrella,但本属菌褶明显花斑状。全球报道有6个种(Sathe & Daniel, 1980; Gerhardt,1996; Guzman et al ,2000),中国文献只报道了1种(臧穆等,1996)。本文报道该属的一个中国新记录种。 小孢疣孢斑褶菇 图1 Panaeolina microsperma Natarajan & Raman, Bibl. Mycol. 8…  相似文献   

6.
松科的落叶松属(Larix L.)约有18种, 我国产10种和1变种,另引进栽培2种Ell0该 属植物为我国北方地区的重要造林树种和经济 用材树种。其中本文所观察的华北落叶松为我 国特产。 该属的染色体已有一些研究和一般性的综 述[5.1.87,但涉及我国产的种类很少。国内的研 究则尚缺。本文报道了,种落叶松的核型分 析,讨论了其核型特征与地理分布的联系。现 将结果报道如下。  相似文献   

7.
我国爬虫恙螨四新种   总被引:1,自引:0,他引:1  
爬虫恙螨属Herpetacarus系Vercammen-Grandjean(1960)所建立,该氏根据须跗毛的种类、数量又在本属下先后建立了三个亚属:Herpetacarus s.str.须附毛=7 B.S;Abon-nencia V-G,1960须跗毛=7 B;Cricacarus V-G,1966须跗毛=6 B.S。 爬虫恙螨属种数较多,仅Vercammen-Graridjean建立本属时即综述了33种,以后国外  相似文献   

8.
重楼属是延龄草科一个特征鲜明的属,共约17—18种,分布于欧洲和亚洲,以中国为分布中心。在区别重楼属下各级类群时,最为有效的指标为:1.花基数(3-)4—10,花辫或萼片数与心皮数目相同;2.雄蕊2—6轮,其数目为心应数目(或萼片数,或花瓣数)的2—6倍;3.子房1室具(3-)4—10个侧膜胎座或数室而具中轴胎座,果为开裂的蒴果或不开裂的浆果;4.种子具多汁的假种皮、具不完全的假种皮或无假种皮;5.根状茎粗壮或细长匍匐.根据属内系统发育的趋势,可以确认:海南重楼Paris dunniana Levl.具粗厚根状茎、雄蕊4—6轮、子房1室具侧膜胎座、蒴果开裂、种于具完全的假种皮,是本属最原始的1个种。根据上述指标,本属划分为2个亚属7个组,其系统顺序如下.  相似文献   

9.
中国杭子梢属植物的研究   总被引:2,自引:0,他引:2  
傅沛云 《植物研究》1987,7(4):11-55
本文叙述了杭子梢属(gen.Campylotropis)植物的研究历史,说明在中国一共记录过59种杭子梢属植物,经过著者的研究整理,确定并提出了14种新的异名名称,经过详细考订,本属植物在中国已确知为29种、6变种、6变型。其中包括经发现和研究整理的新种4、新变种3、新变型3、新组合变种2、新组合变型3。此外尚有2个存疑种有待今后采集调查解决。本文历述了关于本属是否应该并入胡枝子属(gen.Lespedeza)这一问题所存在的长期争议之后,详细论述了本属与胡枝子属在特征上的异同诸点、进行了比较和分析,据此,明确地肯定本属与胡枝子属亲缘关系极为相近,但特征的分化已经必须确认本属应是与胡枝子属有明确区别的独立的属。此外,从特征分析中也可得出本属应是由胡枝子属大胡枝子组(sect.Macrolespedeza)演化发展而来的。本文在讨论了属内主要特征的演化趋势与种群关系之后,论述了本属在世界主要分布地区的种数和分布概况,同时将此与胡枝子属大胡枝子组的分布概况作了比较和分析,明确地认定我国机子梢属植物的大部分种类是本国西南地区发生的(中国有20个特有种),我国的西南地区是本属植物的分布中心,也是本属植物从较原始特征开始分化的一个特征分化多样化中心,并且此地区正是胡枝子属大胡枝子组与本属多数种类包括较原始种类分布相交叉的地区,因而我国的西南地区有可能即是本属植物的起源中心,并且这一起源应是与胡枝子属大胡枝子组植物分布到中国西南地区以后的分化发展想联系的。  相似文献   

10.
异环足摇蚊属隶属于双翅目摇蚊科直突摇蚊亚科,全世界已记录4种。本文对中国产本属进行了系统研究。记述了2新种:简异环足摇蚊A.simplex sp.nov.和扎陵异环足摇蚊A.zhalingensis sp.nov.,重新核定了亮异环足摇蚊A.lucens(Zett.)。提供了世界本属雄成虫检索表。依据中国标本和相关文献,对Cranston等1989年所描述的本属的触角比、前足比、下附器的形状等属级鉴别特征予以订正。模式标本均保存于南开大学生物系。简异环足摇蚊A.simplexsp.nov.:正模:雄性,西藏建日,9/3/1987,邓成玉采。与本属已知种的区别:后足胫节无栉;无额鬃和唇基毛; R2+3脉清晰。扎陵异环足摇蚊A.zhalingensis sp.nov.:正模:雄性,青海扎陵湖,8/20/1986,任淑智采。与本属已知种的区别:个体大;无唇基毛;翅臀叶强烈突出,半球状;下附器三角形,强烈骨化,抱器端节具有13根粗长的刚毛。  相似文献   

11.
12.
13.
14.
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   

15.
16.
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   

17.
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   

18.
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   

19.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号