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1.
This paper deals with the morphological and cytological variation in various forms of P. odoratum complex. A quantitative analysis on the correlation between some diagnostic characteristics was also made with pictorialized scatter diagram and histogram. The results show that the presence or absence of angles on stems is closely correlated with smooth or verrucate lower surface of leaves and the position of stamens (above or below the middle). With chromosome numbers, they heve 2n=18 and 2n=20 respectively. It is suggested to treat them as two distinct species and restore P. simizui Kitag as species status.  相似文献   

2.
海南省3个国家级自然保护区外来入侵植物的调查和分析   总被引:7,自引:2,他引:7  
通过野外实地调查,对海南省的3个国家级自然保护区外来入侵植物的种类数量和分布现状进行了调查分析。结果表明,铜鼓岭、东寨港和大田3个国家级自然保护区内的外来入侵植物分别为35、38和37种,总计18科55种,入侵途径以无意传播为主。绝大多数外来入侵植物已在保护区内建立稳定的繁殖种群,其中飞机草(Eupatorium odoratum L.)、假臭草(Eupatorium catarium Veldkamp.)、胜红蓟(Ageratum conyzoides L.)、刺花莲子草(Alternanthera pungens H.B.K.)、曼陀罗(Datura stramonium L.)、龙珠果(Passiflora foetida L.)及仙人掌[Opuntia stricta(Haw.)Haw.]等7种外来入侵植物对保护区生态环境及生物多样性的危害和影响最大。依据保护区内外来入侵植物的特点和生态影响,提出了一些有效的管理措施和防治建议。  相似文献   

3.
大别山区六种黄精属植物的五种同工酶分析   总被引:5,自引:2,他引:3  
陈存武  周守标   《广西植物》2006,26(4):395-399
采用聚丙烯酰胺凝胶电泳法对皖西大别山区六种黄精属植物的抗坏血酸氧化酶(AOD)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)、酯酶(EST)和过氧化物酶(POD)五种同工酶进行了比较分析。结果表明:(1)五种同工酶共显示出66条酶带,其中有3条是黄精属的特征酶带;并且来源于不同种的同一种酶的谱带数、相对迁移率、酶活性均不相同,呈现多样性;(2)五种同工酶谱的模糊聚类分析结果与形态学分类的结果一致,利用酶谱差异可以将六种黄精初步区分;(3)在六种黄精属植物中,湖北黄精、轮叶黄精、多花黄精和金寨黄精是较进化类型,玉竹和长梗黄精是较原始类型。  相似文献   

4.
The taxonomy of Pilayella littoralis (L.) Kjellm. is confused due to the extreme variability of the species. A numerical taxonomic study has been carried out using computer clustering techniques on 71 morphological and ecological characters with 163 plants from a wide range of habitats in Britain, and the status of the clusters formed scrutinized with reference to the original data. On this basis certain clusters were grouped together as seasonal variants of similar entities. Estuarine plants tend to have in common a number of characteristics which separate them from those collected in marine habitats, such as a much higher incidence of opposite branching and considerably finer filaments. A number of other environmental gradients other than salinity can be associated with these characteristics, for example substrate, exposure etc. The fact that seasonal morphological variation is also common, especially in marine populations, underlines the complexity of the relationship between environment and form in the species, and it is concluded that the establishment of a practicable natural classification of intraspecific variation in P. littoralis is impossible.  相似文献   

5.
红河流域的外来人侵植物   总被引:8,自引:2,他引:8  
红河流域是中国生物多样性最为丰富的地区,植物区系起源古老,生态系统类型复杂多样.本文论述了红河流域外来入侵植物的现状,列举了73种红河流域外来入侵物的种类,对危害比较严重的紫茎泽兰、飞机草、马樱丹、肿柄菊、凤眼莲和空心莲子草6种植物作了具体介绍.对外来入侵植物的控制对策,入侵植物本身的生物学特性的研究、保护生物多样性和退化生态系统的恢复以及路域生态系统管理等几方面作了论述.结果表明,减少人类对生态系统的干扰和破坏,恢复本地植被是防止外来入侵植物入侵的有效途径.  相似文献   

6.
安徽黄精属(Polygonatum)植物的分支分析   总被引:8,自引:1,他引:7  
周守标  张小平  张定成  邵建章   《广西植物》2000,20(4):329-331
以形态学为依据 ,结合细胞分类学、叶表皮和花粉形态的研究成果 ,用分支分析的方法探讨了安徽产黄精属 11种植物的种间演化关系。在分支分析中 ,选择万寿竹属、舞鹤草属和竹根七属作为复合外类群。根据复合外类群比较原则和一般演化规律 ,确定性状极性。结果表明 :( 1)琅琊黄精与长苞黄精为姊妹群 ,并与其余 9种黄精明显分为 2大支 ;( 2 )另一支 9种黄精中 ,玉竹、长梗黄精和金塞黄精亲缘关系密切并与其余 6种再分为 2支 ;( 3)剩下 6种黄精中 ,距药黄精和多花黄精 2种互生叶黄精极为密切并与 4种轮生叶黄精分为 2组 ;( 4 ) 4种轮生叶黄精中 ,黄精、轮叶黄精和安徽黄精亲缘关系最为密切  相似文献   

7.
Maximum parsimony analysis of DNA sequence data from the internal and external transcribed spacer (ITS and ETS) regions of 18S-26S nuclear ribosomal DNA and the 3' trnK intron of chloroplast DNA from over 60 populations of Lasthenia sect. Amphiachaenia yielded a well-supported tree showing that the most common species of Lasthenia, L. californica sensu lato (s.l.), is not monophyletic. Members of Lasthenia californica s.l. belong to two well-supported but morphologically cryptic clades. One clade includes members of L. macrantha; the other represents a basally divergent lineage in L. sect. Amphiachaenia. Members of each clade can be diagnosed by pappus morphology and by geographic distribution, except for epappose plants that occur in a broad region of sympatry in central California. Overall diversification in the clade corresponding to L. sect. Amphiachaenia has been accompanied by minimal morphological divergence, which has resulted in previously underappreciated cryptic diversity.  相似文献   

8.
Despite a general paucity of studies on marine algae in Costa Rica, within the red algal order Gelidiales, 9 species are reported from the Caribbean, and 6 species from the Pacific. In this study 5 species from the southeast Caribbean coast and 2 species from the northwest Pacific coast of Costa Rica were collected for DNA sequence and morphological analyses. At the time of this writing, morphological observations of four Caribbean taxa have identified them as Gelidium microdonticum , Pterocladiella capillacea , P. melanoidea , and Gelidiella acerosa. In rbc L sequence analyses, Gelidium microdonticum is resolved within a clade of small Gelidium species predominantly found in the south Atlantic. Two collections representing different forms of Pterocladiella melanoidea sensu Dawson were found to have identical rbc L sequences. These samples were resolved in rbc L trees with a taxon from Texas identified as P. bartlettii and not P. melanoidea from Europe. Comparisons with type material are being made to verify these identifications so that the status of P. melanoidea in the Caribbean may be determined. The unidentified Caribbean taxon is resolved as a distinct species within the Pterocladiella clade as well. Gelidiella acerosa from Caribbean Costa Rica is closely allied with other Caribbean G. acerosa samples in rbc L trees. The two pacific taxa are small intertidal turf species and have not yet been identified. Sequence analyses resolve these taxa within a large clade of Indo-Pacific and Caribbean Gelidium species.  相似文献   

9.
Variation in floral sex allocation in Polygonatum odoratum (Liliaceae)   总被引:2,自引:0,他引:2  
BACKGROUND AND AIMS: It is well known that resource allocation to male and female functions can be highly variable in hermaphroditic plants. The purpose of this study was to investigate variations in sexual investment at different levels (flower, plant and population) in Polygonatum odoratum, a plant with sequentially opening flowers. METHODS: Pollen and ovule production in base, middle and top flowers of P. odoratum flowering shoots from two natural populations were quantified. Plant measurements of phenotypic and functional gender were calculated in both populations. Total leaf number was used to investigate the relationship between gender assessments and plant size. KEY RESULTS: Pollen and ovule production varied depending on flower position, although the precise pattern differed between both studied populations; only investment in female floral function decreased markedly from base to top flowers in both populations. The frequency distribution of phenotypic gender and their relationship with plant size differed between populations. Phenotypic and functional gender were correlated in both populations. CONCLUSIONS: Sexual investment in P. odoratum has shown a marked variability within plants, among plants, and between populations, which confirms the importance of analysing sex expression in plants of this type. Differences in relative investment in male and female components (phenotypic gender) are reflected in the functional gender and it would be expected that the evolution of sexual specialization in Polygonatum odoratum would be promoted.  相似文献   

10.
广西的外来入侵植物   总被引:7,自引:1,他引:6  
通过野外调查,结合相关文献资料,发现广西目前有外来入侵植物约74种,隶属于57属26科,其中,菊科的种类最多,有19种,其次是禾本科,有10种。草本植物最多,占总数的78.4 %。从来源看,大多来源于美洲。在广西,危害较为严重的外来入侵植物主要是紫茎泽兰、飞机草、银胶菊、凤眼莲等11种。此外,还进一步论述了外来植物在广西的基本特征和入侵成因,分析其在广西的发展状况,预测其可能入侵的区域,并提出了有关的防治对策。  相似文献   

11.
According to the information including type material with regard to Raphiolepis major Card. and R. indica (L.) Lindl., the morphological differences between these two closely related taxa are largely quantitative, i.e., the former has larger leaves, flowers and fruits, and longer petioles and pedicels than the latter. But since these characteristics are rather variable, they can hardly be proven to be sound in separating these two taxa as distinct. By using methods of quantitative analysis with scatter diagrams on herbarium materials, we have found that the characteristics used to discriminate the two taxa either tend to display continuous variational patterns, or vary at random. Both eases suggest that the morphological variations of individual sample plants are probably due to the different modes of growth or development of plants in response to varied environments. Since these two taxa are taxonomically inseparable from each other as a whole, it seems advisable to treat them as one single species. Thus, the lately published R. major Card.should be reduced to a synonym of R. indica (L.) Lindl.  相似文献   

12.
The problems of delimitation of species of Prosopis originate from the few morphological discontinuities which exist among some of them; some, however, originated as a result of wide distribution of germplasm without proper knowledge of the species, in particular, much material catalogued as P. juliflora, but being of other species, was distributed for reforestation projects worldwide. This work tests the morphological results obtained for P. pallida and P. limensis of the Peruvian–Ecuadorian coast and for P. juliflora of the Caribbean Basin of Colombia and Venezuela utilizing a study of AFLPs and a study of the morphology of plantlets developed in a conventional garden study. The phenogram obtained for the AFLPs demonstrates each of the three species to be a well differentiated cluster and the molecular variance between them is significantly greater than the variance within each species. Study of the plantlets also indicates statistically significant differences for four morphological characters between P. juliflora and the other two species (P. pallida and P. limensis). These results, in addition to the morphological differentiation evident between adult plants of P. pallida and P. limensis and the clear separation of these two species from P. juliflora, corroborate the genetic identity of the three taxa analyzed.  相似文献   

13.
Searching and study on regulatory proteins, which can keep under control the scope of important processes as like as cell adhesion, proliferation, differentiation and morphogenesis, is an actual aim of the current biochemistry. Recently we have identified S-100 proteins in plants of following species: plantain (Plantago major L.), aloe (Aloe arborescens L.), and bilberry (Vaccinum myrtillus L.). Extraction and purification of S-100 proteins gotten from these plants were performed by the method we developed earlier for adhesion proteins of animal tissues. Homogeneity of the studied plant proteins was evaluated and confirmed by HPLC and SDS-electrophoresis in PAAG. Both, plant and animal proteins have appeared to be biologically active at extremely low doses. The tests were performed by adhesiometrical method in short-term tissue culture of mouse's liver in vitro. As a result it was established that the plant proteins insert a membranotropic effect being added in extremely low doses, corresponding to 10(-10)-10(-13) mg/ml. Keeping in mind that the plantain is well known remedy for wound protection and healing, in several experiments we studied the biological effect of plant S-100 proteins on animal cells. It was found that S-100 proteins obtained from plantain influences proliferation of human fibroblasts in vitro. It was found that after the treatment with this protein in low doses the cell growth rate increases essentially.  相似文献   

14.
As part of a large project to determine rooting depth and resource uptake on the Edwards Plateau of central Texas, we developed a DNA-based technique that allows the below-ground parts of all plants to be identified to the level of genus and usually to species. Identification is achieved by comparing DNA sequences of the internal transcribed spacer (ITS) region of the 18S-26S nuclear ribosomal DNA repeat, derived from below-ground plant material, with a reference ITS region database for plants at a site. The method works throughout plants because the plant ITS region can be PCR amplified using a set of universal primers. Congeneric species can usually be identified because the ITS region evolves relatively rapidly. In our study, all roots were easily identified to the level of genus; most congeneric species were identified solely by ITS sequence differences but some required a combination of ITS sequence data and above-ground surveys of species at a site. In addition to showing the feasibility and efficacy of our technique, we compare it with another DNA-based technique used to identify below-ground plant parts. Finally, we also describe a DNA extraction and purification technique that reliably provides high-quality DNA of sufficient quantity from roots so that PCR can be readily accomplished. Our technique should allow the below-ground parts of plants in any system to be identified and thereby open new possibilities for the study of below-ground plant communities.  相似文献   

15.
从5种松树健康的枝、叶、干中共分离了2,400个组织块,得到199株内生拟盘多毛孢Pestalotiopsis,形态学和分子生物学鉴定分属于11个种,平均分离率为8.29%。所得11种内生拟盘多毛孢都是首次在四川的松属植物中分离得到,其中葡萄生拟盘多毛孢P.uvicola和山桃草拟盘多毛孢P.gaurae为首次在松树上分离得到。基于ITS序列的分子系统发育分析显示松树内生拟盘多毛孢种类之间存在一定的遗传差异,部分内生拟盘多毛孢与病原拟盘多毛孢的ITS序列具有很高的同源性。  相似文献   

16.
深圳大鹏半岛“风水林”香蒲桃群落特征及物种多样性研究   总被引:11,自引:0,他引:11  
根据样方调查,对罕见的大鹏半岛"风水林"香蒲桃群落的区系组成、外貌、群落结构特征和物种多样性进行分析,并与邻近4个地区的森林群落作比较。结果表明,该群落属于南亚热带次生性常绿阔叶林,在1200m2样地中,有维管束植物86种,隶属于44科80属,其中以热带性分布属占明显优势,所占比例为89.33%。群落主要优势种为香蒲桃、乌饭树、银柴、密花树。群落外貌终年常绿,生活型以高位芽为主,占86.05%;通过对优势种群的年龄结构分析显示,该群落处于增长状态,按照Raunkiaer的频度等级定律,属于A级的种类最多,频度值为52.32。整个群落物种丰富度Magarlef指数为9.65,Shannon-Wiener指数为3.17,均匀度指数为0.71,3个层次多样性格局为"灌木层>乔木层>草本层"。物种多样性比较结果显示,大鹏半岛香蒲桃群落的物种多样性水平高于受不同程度干扰的深圳南山假萍婆群落和澳门假苹婆群落,但比保护较好的香港黄桐群落和鼎湖山厚壳桂群落低,过度的人为干扰将导致植物物种多样性的降低。  相似文献   

17.
伞形科囊瓣芹属的表型分析   总被引:1,自引:0,他引:1  
选取伞形科(Apiaceae)囊瓣芹属(Pternopetalum Franchet)32个分类群的60个形态学性状,利用DELTA系统的UPGMA算法进行了聚类分析。结果表明属下形成以五匹青(P.vulgare(Dunn)Hand.-Mazz.)和东亚囊瓣(P.tanakae(Franchet&Sav.)Hand.-Mazz.)为代表的两个主要表征群。两个主要表征群的分类结构和各自所包含的类群基本相应于前人研究中本属两个组的属下处理。根据全面相似性分析的结果和部分形态学特征的评估,确认了属下6个种的复合群:即五匹青、囊瓣芹(P.davidii Franchet)、散血芹(P.botrychioides(Dunn)Hand.-Mazz.)、洱源囊瓣芹(P.molle(Franchet)Hand.-Mazz.)、澜沧囊瓣芹(P.de-lavayi(Franchet)Hand.-Mazz.)和东亚囊瓣芹复合群。根据形态学特征在表型树上的分布分析表明:伞形花序的着生位置、花柱的形态、花柱基的形状和萼齿的大小等生殖特征可能是属下早期分化的关键性性状。属下主要变异类型(种的复合群和典型狭域特有种)对不同海拔区域和小生境的依赖,以及不显著的形态学分化表明:对横断山区较高的异质性生境的生态适应是囊瓣芹属类群多样化过程后期的一个重要特征。  相似文献   

18.
本文对部分风媒植物花粉形态特征,及其母体植物地理分布情况进行了对照研究。在此基础上发现,同一分类系统内,小个体花粉者,其母体植物地理分布趋向于较优越环境。对于具气囊花粉而言,具较大气囊者,或者花粉本体较小者,其母体植物趋向于分布在低纬度或较低海拔环境。并且,产大个体或球状花粉者,往往具有较强的单种成林倾向。本文首次指出了花粉形态与母体植物地理分布间存在着一定的统计学关系,并首次将动态概念引入植物生态学领域,认为花粉形态特征作为一项重要的参变量,通过种间生存竞争过程对母体植物适应倾向施加影响,进而影响物种的生活习性。那些在花粉的传播及授粉过程中稍占优势的物种,其自然分布域趋向于比较优越的环境。本文仅作为一种尝试,试图为动态植物生态学研究,乃至植物生态演化学研究提供一个新的研究思路。  相似文献   

19.
Before the advent of molecular phylogenetics, species concepts in the downy mildews, an economically important group of obligate biotrophic oomycete pathogens, have mostly been based upon host range and morphology. While molecular phylogenetic studies have confirmed a narrow host range for many downy mildew species, others, like Pseudoperonospora cubensis affect even different genera. Although often morphological differences were found for new, phylogenetically distinct species, uncertainty prevails regarding their host ranges, especially regarding related plants that have been reported as downy mildew hosts, but were not included in the phylogenetic studies. In these cases, the basis for deciding if the divergence in some morphological characters can be deemed sufficient for designation as separate species is uncertain, as observed morphological divergence could be due to different host matrices colonised. The broad host range of P. cubensis (ca. 60 host species) renders this pathogen an ideal model organism for the investigation of morphological variations in relation to the host matrix and to evaluate which characteristics are best indicators for conspecificity or distinctiveness. On the basis of twelve morphological characterisitcs and a set of twelve cucurbits from five different Cucurbitaceae tribes, including the two species, Cyclanthera pedata and Thladiantha dubia, hitherto not reported as hosts of P. cubensis, a significant influence of the host matrix on pathogen morphology was found. Given the high intraspecific variation of some characteristics, also their plasticity has to be taken into account. The implications for morphological species determination and the confidence limits of morphological characteristics are discussed. For species delimitations in Pseudoperonospora it is shown that the ratio of the height of the first ramification to the sporangiophore length, ratio of the longer to the shorter ultimate branchlet, and especially the length and width of sporangia, as well as, with some reservations, their ratio, are the most suitable characteristics for species delimitation.  相似文献   

20.
Plant populations at high elevation face extreme climatic conditions and resource limitations. The existence of distylous species at different elevations can help us investigate their adaptation to high altitudes, the evolution of their morphological characteristics, as well as their responses to limited resources. Here, 17 populations of Primula nivalis at different elevations were evaluated regarding variations in plant morphological characteristics, biomass allocation, and morphological plasticity in a heterogeneous environment. Our results demonstrate that heterogeneous environments can affect plant morphological characteristics and resource allocation in each sexual morph of these plants. Moreover, environmental variations reduced morphological plasticity in the two plant morphs, and the plasticity of long style (LS) plants was greater than that of short style (SS) plants. There were significant negative correlations between morphological characteristics and elevation, rainfall, temperature, and sunshine, and these are the main variables that affect morphological characteristics and resource allocation of both morphs of P. nivalis plants in heterogeneous environments. The morphological characteristics of P. nivalis plants transplanted from high to lower elevations were not significantly different in either population. LS plants had greater morphological plasticity and adaptability in heterogeneous environments than SS plants. Elevational gradients and heterogeneous environments differentiated both morphs of P. nivalis plants with regards to morphology as well as adaptations. LS plants showed a higher level of adaptability than SS plants.  相似文献   

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