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1.
重寄生属植物及其寄主的地理分布   总被引:1,自引:0,他引:1  
李冬雪  丁雨龙 《广西植物》2005,25(2):117-120
通过对重寄生属植物及其寄主的地理分布状况的讨论,对重寄生属植物可能的起源时间、地点与迁 移进行了分析。重寄生属植物主要寄生在桑寄生科(Loranthaceae)植物上,重寄生属植物的分布区与其寄主 的基本一致,均主要分布在东南亚和中国南部的热带与亚热带地区;重寄生属植物可能起源于第三纪之前某 一时期的华南热带地区,随后向周边地区扩散。在第三纪,重寄生属植物的祖先偶然寄生在桑寄生科某些寄 生植物祖先上,经过几千万年的协同进化,形成了今天比较稳定的寄生与寄主关系。  相似文献   

2.
中国珍稀濒危保护植物名录   总被引:11,自引:0,他引:11  
植物是生命的源泉,保护植物资源就是保护人类赖以生存的物质基础。本世纪以来,由于缺乏科学的持续利用植物资源的规划,随着生产建设的发展和人类自身活动及自然因素的影响,使许多植物遭到越来越严重的破坏,有的处于濒临灭绝的境地,甚至已经绝灭。为此,国家环保部门会同中国科学院植物研究所等组织全国各有关部门的专家,在调查研究的基础上,经反复讨论审议,确定了我国第一批珍稀濒危保护植物名录。1984年10月9日,国务院环保委员会在《中国环境报》上公布了这个名录。在此基础上,又进行了认真调整和补充,由科学出版社出版,1987年第一季度在各地新华书店发行。《名录》中所列植物是从我国自然生长的蕨类植物、裸子植物和被子植物中选择确定的,共有389种。其中蕨类植物13种,裸子植物71种,被子植物305种,划为濒危(即临危)类别的121种,稀有类别的110种,渐危(受威胁)类别的158种。按重点保护级别分,列为一级重点保护的8种,二级重点保护的160种,三级重点保护的221种,其保护级别尚需国家审批后决定。根据《中华人民共和国野生植物资源保护条例(草案)》规定,一级重点保护植物是指中国特有,并具有极为重要的科研、经济和文化价值的濒危、渐危或稀有的种类;二级重点保护植物是指在科研或经济上有重要意义的濒危或渐危的种类;三级重点保护植物是指科研或经济上有较重要意义的渐危或稀有的种类。濒危的种类,系指处在灭绝危险中的植物,这些植物比较稀少,地理分布也有很大的局限性,如果对它的生长和繁殖不利的因素继续发生,它就很难生存下去。渐危的种类,系指目前虽然还未处于濒危状态的非单属种植物,但在其分布区内由于生境条件的变化,已经看出有走向衰落的迹象。稀有的种类,系指我国特有的单种科、单种属和少数种属代表植物,其分布区比较狭窄,生态环境比较独特,或分布范围虽广但比较零星的植物种类,目前虽没有处于渐危或濒危状态,但由于分布上的局限性,只要不利生境因素出现,很容易变成渐危或濒危的状态。为了便于使用,《名录》以受威胁类别、植物科属和分省三种方式排列,每种植物列有中名、拉丁名,隶属科名以及保护级别和分布。凡分布狭窄或分布于某省不足三个县的种类均在省名后括以县名或山名。这里只按保护级别和受威胁类别刊登。  相似文献   

3.
江西九岭山脉种子植物区系研究   总被引:1,自引:0,他引:1  
九岭山脉植物区系发生历史悠久,对研究我国早期种子植物演化、动植物迁徙、物种分布格局均具有重要作用。为探讨九岭山脉种子植物区系成因和濒危保护植物的保护利用,该文通过野外调查、标本采集和鉴定,结合经典植物地理学方法,对该山脉种子植物区系进行了研究。结果表明:(1)九岭山脉共有野生种子植物211科956属2928种,占江西种子植物1064属4028种的比例分别为89.8%和72.69%。(2)该植物区系的热带成分科占该地区种子植物总科数(不含世界分布科)的81.35%,但缺乏典型热带成分科,区系中的热带性属和温带性属数量接近,显示该植物区系由热带性质向温带性质过渡,这与九岭山脉地处重要的气候和生态交错地带有一定关联。(3)该地区共分布中国特有植物6科33属41种,特有属主要为古特有属,体现了该植物区系起源的古老性,推断该山脉在第四纪冰期环境较为稳定,为众多植物提供了“避难所”。(4)该地区的种子植物中有30科63属109种为国家重点保护植物,其中,国家I级保护植物15种,极危植物3种、濒危植物11种、易危植物20种。该山脉中的九岭山、官山和大围山已有相应的自然保护区发挥生态保护作用,而其余的山地则未建立有效保护,应对相关濒危植物所在区域加以监管,可采取就地保护或迁地保护等措施,建立相关的种质资源库,确保濒危保护植物的可持续利用。  相似文献   

4.
安徽大别山区种子植物区系的初步研究   总被引:1,自引:0,他引:1  
通过对安徽大别山区种子植物资料收集和实地勘察,在此基础上得到了安徽大别山区种子植物区系的特征和珍稀濒危保护种子植物的分布,并与周边山区进行了对比分析。结果表明:(1)安徽大别山区种子植物种类繁多、类型丰富,区域内种子植物共计145科,731属,1 648种(不含种以下分类)。(2)通过统计和PCA方法分析,表明安徽大别山区植物区系整体上呈现亚热带向温带过渡的性质。(3)安徽大别山区与岳西古井园种相似性系数最高(64.52%),与清凉峰次之(40.22%),与舒城万佛山最低(24.65%)。(4)安徽大别山区内含21种珍稀濒危保护种子植物,包括5种濒危植物、2种国家一级保护植物和14种国家二级保护植物。  相似文献   

5.
采取线路调查法,对塔里木盆地西南山区珍稀濒危植物的种数、习性、分布特征及濒危状况进行了调查和分析。结果显示:该区域共有珍稀濒危植物67种,隶属31科40属,其中,蕨类植物1科1属1种,裸子植物2科2属13种,被子植物28科37属53种;被子植物中,双子叶植物有25科32属48种,单子叶植物有3科5属5种。景天科(Crassulaceae)的红景天属(Rhodiola Linn.)和麻黄科(Ephedraceae)的麻黄属(Ephedra Tourn ex Linn.)种类均较多(10种以上)。从习性看,多年生草本和灌木种类较丰富(分别为31和26种),乔木、寄生植物和一年生草本种类依次有7、2和1种。从垂直分布看,该区域珍稀濒危植物的海拔分布范围为1 500~5 600 m,种数随海拔升高呈先增后减的趋势;从水平分布看,以塔什库尔干塔吉克自治县和叶城县为中心向北或向东,珍稀濒危植物种类渐少;集中分布区为塔什库尔干塔吉克自治县和叶城县西南山区海拔2 000~4 500 m的中山带、亚高山带和高山带。在这些珍稀濒危植物中,属于濒危野生动植物种国际贸易公约(CITES)附录Ⅱ(2013版)收录的种类仅小斑叶兰[Goodyera repens(L.)R.Br.]1种;属于《中国植物红皮书》收录的种类有裸果木(Gymnocarpos przewalskii Maxim.)和胡杨(Populus euphratica Oliv.);属于《中国物种红色名录》收录的种类有46种,包括极危种2种、濒危种5种、易危种8种;属于国家重点保护野生植物名录(第一批)收录的种类有裸果木和昆仑方枝柏(Sabina centrasiatica Kom.);属于新疆维吾尔自治区重点保护野生植物名录收录的种类有43种,其中,新疆Ⅰ级、Ⅱ级和Ⅲ级重点保护野生植物分别有31、10和2种。总体上看,塔里木盆地西南山区的珍稀濒危植物种类较为丰富,但由于生境和气候恶劣,加之部分种类的种群规模减小并具有间断分布的特点,这些种类面临较高的灭绝风险。根据研究结果,提出扩大自然保护区范围、增加保护强度、优先保护受威胁种类及注重孑遗种的科学研究等保护策略。  相似文献   

6.
牛背梁自然保护区种子植物多样性研究   总被引:5,自引:0,他引:5  
对牛背梁自然保护区的种子植物多样性进行了研究。据统计,种子植物950种,隶属105科433属,其中,裸子植物4科8属9种,被子植物101科425属941种;木本植物372种,草本植物578种;珍稀濒危保护植物17种,资源植物丰富,分为药用,观赏,食用等10大类型,生态系统多样,按大的类型可划分为森林,灌丛,草甸,裸岩和农田,其中森林面积15055hm^2,占总面积的91.7%。是生态系统的主体。在此基础上,本文还提出了保护植物多样性应采取的对策。  相似文献   

7.
马金双   《广西植物》1989,9(4):367-369
<正> 马兜铃属Aristolochia L.是马兜铃科Aristolochiaceae的一个大属,全世界约400种,主产于热带和亚热带,温带有少量分布。我国有50多种,主产横断山至华南一带。作者根据近年来的野外调查、采集及对存于国内外标本室的大量本属标本鉴定,参照有关资料的划分原则,发现该属植物在我国已有多种处于濒危、渐危或稀有状态。据已知的51种统计,除11个广布种外,其余40种(80%为我国特产)均为狭域分布,而且种群数量极为稀少;其中3  相似文献   

8.
据Delacour(1951)全世界共有雉类16属48种,我国就有12属(占全世界总属数75%)、26种(占55%)。我国雉资源居世界第一位。 (一)雉类现状令人忧虑据《野生动物保护法》附录中的国家重点保护野生动物名录,已列入保护名录的雉科鸟类有25种,占我国雉科鸟类总种数96.2%,其中属于国家一级保护动物有14种,占53.8%,二级保护动物有11种占,42.3%;世界鸟类“红皮书”(1982)上列举世界濒危雉类14种中,中国有九种,占全世界濒危总种数64.3%。上述数字表明我国雉类中的大多数已处于濒危状态,急待保护。雉类数量日趋下降的主要原因有:①森林是雉类赖以生存的主要条件,是栖息、繁衍生息的场所。如我国极为珍贵的一级保护动物绿孔雀、  相似文献   

9.
为进一步了解杭州市植物区系的组成和特点,通过查阅资料,整理了杭州市域范围内分布的中国特有种子植物名录,并在此基础上,对研究区内特有种子植物的科属构成、生活型、区系组成、重点保护种类和濒危种类等进行统计和分析。结果显示:研究区内中国特有种子植物共100科328属708种,种类构成以被子植物为主,生活型以草本最多。区系组成上,科级水平以热带性分布成分为主,而在属级水平,则是以温带分布的属最多,说明研究区区系成分复杂。国家重点保护野生植物有31种,濒危植物中受威胁物种有46种。研究结果可为开展特有植物的生物多样性保护提供参考资料。  相似文献   

10.
根寄生植物种子萌发刺激物研究进展   总被引:4,自引:0,他引:4       下载免费PDF全文
周峰  陈君  徐荣  于晶 《植物生态学报》2009,33(3):607-616
根寄生植物是被子植物中一类寄生在寄主根部, 以摄取寄主水分和营养物质为生的特殊植物类群, 其种子萌发需要寄主萌发刺激物的诱导。该文主要阐述根寄生植物种子萌发的特异性, 以及目前已发现的刺激种子萌发的信号物质及其调节机制和生物合成途径, 并就萌发刺激物的识别机制及其在根寄生植物或丛枝菌根真菌与寄主建立寄生关系过程中所起的作用进行综述, 提出根寄生植物种子萌发研究中存在的问题, 并对其研究前景进行了展望。  相似文献   

11.
Based on the geographical distribution of the species of Phacellaria and its host plants in the world,we speculated on the possible time,sites,and migration of the origin of Phacellaria.The host plants of Phacellaria mainly belong to Loranthaceae.Plants of Phacellaria and their hosts are mainly distributed in tropical and subtropical areas.The plants of Phacellaria might have originated from a tropical area in the south of China before the Tertiary.Their ancestors were parasitic on the ancestors of some plants of Loranthaceae by chance during the Tertiary.It possibly took them millions of years to form a sturdy relationship with their hosts.  相似文献   

12.
A high-resolution biostratigraphic analysis of planktic foraminifers confirms that the Bidart section at the eastern margin of the Atlantic Ocean exhibits a continuous and complete Cretaceous/Paleogene (K/Pg) transition interval. The biozones and subzones recorded in this section are less expanded than their equivalent in Tunisian sections: El Kef (Global Stratotype Section and Point: GSSP for the K/Pg boundary) and Ellès (auxiliary section), but they are sufficiently thick to allow a detailed analysis of the evolution of the planktic foraminiferal assemblages across the K/Pg transition.Throughout the uppermost 4 m Maastrichtian, the planktic foraminiferal assemblages are highly diversified, containing up to 72 species. These Maastrichtian assemblages are rich in cosmopolitan taxa (70%), dominated by small biserial morphotypes which belong mainly to the genus Heterohelix which coexist with less abundant but highly diverse tropical and subtropical species.The extinction pattern at the Bidart section suggests a sudden catastrophic mass extinction at the K/Pg boundary which affected at least 53 out of 72 species. The species becoming extinct include globotruncanids (e.g. Contusotruncana spp., Globotruncana spp., Globotruncanita spp.) and complex heterohelicids (e.g. Racemiguembelina spp., Pseudotextularia spp., Gublerina spp.). At the Bidart section, only Archaeoglobigerina cretacea disappears 2 m below the K/Pg boundary event. Specimens of 18 small and even tiny Maastrichtian species, are found at the lowermost Danian. Only a few of these species belonging to the genera of Guembelitria, Hedbergella and Heterohelix are considered to be real “Cretaceous survivor species”, whereas the specimens belonging to the rest, are most probably reworked, because they differ in their preservation.Throughout lowermost Danian, the planktic foraminiferal assemblages are dominated by “opportunistic” species of the genus Guembelitria. These opportunists are associated to small and poorly diversified pioneer globigerinids (Palaeoglobigerina spp. and Parvularugoglobigerina spp.). These assemblages became progressively more diversified across the early Danian containing species with cancellate walls (Eoglobigerina spp., Parasubbotina spp., Subbotina triloculinoides and Praemurica spp.) and new taxa of biserial heterohelicids (Woodringina spp. and Chiloguembelina spp.) suggesting a paleoenvironmental recovery.  相似文献   

13.
The bottom-dwelling and species-rich eelpout genus Lycodes Reinhardt has a great potential for the study of Arctic marine speciation. Subdivision of the genus has been based on single or few morphological characters (e.g., lateral line configuration) with contradicting results and phylogenetic approaches have not been attended. Here we present the first phylogenetic analysis of the genus employing DNA sequences of the mitochondrial genes cytochrome b and 12S rDNA (714 bp). The analysis with the two genes combined resulted in two equally parsimonious trees. In both cladograms most of the previously suggested subgroups are para- or polyphyletic, except for the so-called short-tailed Lycodes spp., with a short tail, a single mediolateral lateral line configuration and a shallow or filled otolith sulcus. The group of long-tailed Lycodes spp., with ventral or ventro-medio-lateral types of lateral line configuration and a deep otolith sulcus, appears to be paraphyletic, since Pacific and Atlantic species in this group are not each other's closest relatives. Thus, the short-tailed species are placed in a derived clade, indicating a secondary shortening of the tail, and a "slope to shore" type of evolution. This is not in accordance with earlier assumptions of the more elongate, deeper living species being the more derived. The basal position of long-tailed Pacific species supports earlier theories of Pacific origin of the genus/family. Small genetic differences between Arctic/Atlantic species indicate a rather recent radiation in these areas after the opening of the Bering Strait 3.0-3.5 million years ago.  相似文献   

14.
Coccodiella is a genus of plant-parasitic species in the family Phyllachoraceae (Phyllachorales, Ascomycota), i.e., tropical tar spot fungi. Members of the genus Coccodiella are tropical in distribution and are host-specific, growing on plant species belonging to nine host plant families. Most of the known species occur on various genera and species of the Melastomataceae in tropical America. In this study, we describe the new species C. calatheae from Panama, growing on Calathea crotalifera (Marantaceae). We obtained ITS, nrLSU, and nrSSU sequence data from this new species and from other freshly collected specimens of five species of Coccodiella on members of Melastomataceae from Ecuador and Panama. Phylogenetic analyses allowed us to confirm the placement of Coccodiella within Phyllachoraceae, as well as the monophyly of the genus. The phylogeny of representative species within the family Phyllachoraceae, including Coccodiella spp., graminicolous species of Phyllachora and taxa with erumpent to superficial stroma from several host families, suggests that the genus Phyllachora might be polyphyletic. Furthermore, tar spot fungi with superficial or erumpent perithecia seem to be restricted to the family Phyllachoraceae, independently of the host plant. We also discuss the biodiversity and host-plant patterns of species of Coccodiella worldwide.  相似文献   

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16.
The reproductive biology of most species of Rafflesiaceae is unknown. We studied several aspects of that of Bdallophyton bambusarum Liebm. (Rafflesiaceae) in a subdeciduous tropical forest. Flowering of B. bambusarum is during the driest time of the year. Male flowers are more numerous, larger, and with more nectar than female flowers, but the nectar from female flowers has a higher sugar concentration. Flies ( Peckia spp., Perckiamya spp.; Diptera: Sarcophagidae) are the pollinators. They make frequent visits, spending more time in the male flowers. Fluorescent dyes applied to track movement indicated extensive pollen flow within populations, and pollen flow could also be occurring between populations. The latter is reflected in the higher genetic variability within, and the great similarity between, populations than previously recorded for the species. Secondary characteristics of dioecious species fit B. bambusarum , but not the trade-off of reproductive resource allocation. Parasitic plants may damage the host, but the mechanism and extent are still unknown.  相似文献   

17.
The palm genus Areca is widespread in tropical Asia and includes the economically important betel nut palm, A. catechu. The genus has three centres of high species diversity: the Sunda Region, the Philippines and East Malesia (to the east of Wallace's line). The taxonomy of the genus in East Malesia has been neglected. Prior to this study, 19 species were accepted for this area, all but one endemic, but their limits and differences were not understood. Here, we provide a taxonomic monograph of East Malesian Areca spp., based on an extensive study of the genus in herbaria and in the field. We recognize six species of Areca in East Malesia, including the widespread cultivated A. catechu. Five wild species are accepted, namely A. macrocalyx, A. mandacanii, A. novohibernica, A. oxycarpa and A. vestiaria. We place 12 of the previously accepted species into synonymy, and provide additional new synonymy in A. catechu. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 147–173.  相似文献   

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本文对狭义小奥德蘑属Oudemansiella s. str.的概念做了修订,在修订后的属中,狭义干蘑属Xerula s. str.的物种不纳入其中。在狭义小奥德蘑属下,提出了一个包含4个组O. sect. Oudemansiella、Mucidula、Dactylosporina 和 Radicatae的新系统。小奥德蘑组sect. Oudemansiella包括热带至南温带的一些物种,如新热带小奥德蘑O. platensis、澳洲小奥德蘑O. australis、旧热带小奥德蘑O. canarii和宽褶小奥德蘑O. crassifolia,这些物种的菌盖表皮为粘栅栏型,由菌丝组成,但其中常夹杂有链状排列的膨大细胞。粘蘑组sect. Mucidula包含北半球温带至亚热带的一些物种,如粘小奥德蘑O. mucida、网褶小奥德蘑O. venosolamellata和近粘小奥德蘑O. submucida,其菌盖表皮为粘子实层-栅栏型,由近棒状的顶端膨大细胞组成。小奥德蘑组和粘蘑组的物种,在外形和小生境上有相似之处,其担子果皆生于地表外的腐木上,菌柄上有或无菌环。刺孢组sect. Dactylosporina包含中南美洲那些孢子表面有指状凸起的物种。长根组sect. Radicatae由长根小奥德蘑O. radicata及其近缘种为代表,是该属中最大的组,包括该属其他三组之外的所有种。北美的O. americana、欧洲的O. caussei 和东亚的O. hongoi曾被置于小奥德蘑属中的白毛组O. sect. Albotomentosae或干蘑属的亮毛组X. sect. Hyalosetae,在本系统中它们没有纳入小奥德蘑属,因为它们可能代表一个单独的属。本文还提出了1新等级、32个新组合和1个新名称。  相似文献   

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