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1.
 克隆植物的形态可塑性在基株和种群水平上分别表现为克隆构型和分株种群特征的变化。研究对象为内蒙古锡林河流域草地、林地、沙地3种生境下的羊草(Leymus chinensis)种群,通过对羊草根茎节间长度、间隔子长度、分枝强度、分枝角度、株高和分株密度等指标的测定和分析,对这3种不同生境中羊草的克隆构型及分株种群特征进行了研究。结果表明羊草克隆构型相关特征,如,根茎节间长度,根茎节间长度频次分布格局、间隔子长度、间隔子长度频次分布格局,在不同生境差异较大。同时,羊草的分枝角度在不同生境间差异显著。而每间隔子所  相似文献   

2.
中国蓼属春蓼组植物果实形态及果皮微形态的研究   总被引:5,自引:1,他引:4  
应用解剖镜和扫描电镜对中国产蓼属春蓼组(Polygonum sect. Persicaria)19种3变种植物的果实形态和果皮微形态特征进行了观察和研究。结果表明,蓼属春蓼组植物的果实形态为卵形或椭圆状卵形,具三棱、双凹或双凸,顶端渐狭,有喙或无喙;果皮微形态可分为7种类型: 洼点、浅洼点,脑纹状纹饰,拟脑纹状纹饰,网状纹饰,不规则褶皱,不规则小疣状颗粒以及密浅网状纹饰。观察结果支持将绵毛酸模叶蓼(P. lapathifolium L. var. salicifolium Sibth.)合并到酸模叶蓼(P. lapathifolium L.),做为酸模叶蓼的异名处理;支持将长鬃蓼(P. longisetum De Br.)作为丛枝蓼(P. posumbu Buch. Ham. ex D.Don)的变种处理的意见;认为密毛酸模叶蓼(P. lapathifolium L. var. lanatum (Roxb.) Stew.)应恢复种级,圆基长鬃蓼(P. longisetum De Br. var. rotunatum A.J.Li)应升为种级;支持平武蓼(Polygonum pingwuense F. Z. Li et Y. T. Hou et S. J. Fan, sp. nov.)新种的成立。  相似文献   

3.
VALERO, M. & HOSSAERT-MCKEY, M., 1991. Discriminant alleles and discriminant analysis: efficient characters to separate closely related species: the example of Lathyrus latifolius L. and Lathyrus sylvestris L. (Leguminosae). Two species of Lathyrus (L. latifolius and L. sylvestris) were compared using allozymes and quantitative vegetative and reproductive traits. The variation in these characters was analysed in several populations of the two species located in south-western, central and northern France. In a site where the two species are syrapatric, intermediate plants are described. The two species can be identified by discriminant alleles. The genetic structure observed for intermediate plants in the zone of sympatry indicates, paradoxically, the occurrence of a strong reproductive barrier between the two species. The discriminant analysis performed on the quantitative traits readily distinguishes the two species and confirms the reproductive isolation between them. The quantitative character that best discriminates between the species is the number of ovules per ovary, a variable which has non-overlapping distributions in the two species. We discuss how this character, usually ignored, may be better for distinguishing species than some traditionally used reproductive traits such as the number of seeds per fruit. The vegetative traits studied (e.g. degree and intensity of branching) also differ significantly between the two species. Divergent evolution of these traits in the two species is discussed in relation to differences in the original habitats of the two species.  相似文献   

4.
二月兰形态性状的变异分析   总被引:10,自引:0,他引:10  
二月兰(Orychophragmus violaceus)是集食用、保健、饲用和观赏于一身的优良地被植物。其遗传背景单一、生长周期短,是发展模式植物的优良材料。为了开发其育种价值,我们对二月兰的形态变异式样进行了初步分析。共选取了北京和南京地区的7个居群的34个表型性状进行观测。通过计算分析发现:株高、茎和花序分枝等性状受环境影响较大,因而其分类价值不大;叶形、毛被、叶缘锯齿等性状的变异在居群内是连续的,所以也不是可靠的分类性状;而花部性状的一些变异,包括花瓣的颜色、大小、形态,基本不受环境影响,且这些变异在居群内是不连续的,所以其分类价值相对较高。对17个数值性状的方差分析和多重比较结果表明,在同一年度内,大部分性状在不同地区间差异不显著,在居群间差异极显著;而在不同年度内,居群间差异不显著。最后,对7个居群和30个表型性状进行了数量分类:Q分析表明北京颐和园、南京紫金山山顶公园和南京中山植物园居群比较相似,而北京圆明园、北京海淀区后八家苗圃、南京情侣园和北京天坛公园居群较相似。R分析揭示了二月兰花部、叶部、反映植株毛被和颜色以及表现植株生长量的性状间均具有一定的相关性。这些研究可为种下等级的划分和进一步的遗传研究以及品种培育提供一定的参数资料。  相似文献   

5.
We investigated the correlated response of several key traits of Lythrum salicaria L. to water availability gradients in introduced (Iowa, USA) and native (Switzerland, Europe) populations. This was done to investigate whether plants exhibit a shift in life-history strategy during expansion into more stressful habitats during the secondary phase of invasion, as has recently been hypothesized by Dietz and Edwards (Ecology 87(6):1359, 2006). Plants in invaded habitats exhibited a correlated increase in longevity and decrease in overall size in the transition into more stressful mesic habitats. In contrast, plants in the native range only exhibited a decrease in height. Our findings are consistent with the hypothesis that secondary invasion is taking place in L. salicaria, allowing it to be more successful under the more stressful mesic conditions in the invaded range. If this trend continues, L. salicaria may become a more problematic species in the future.  相似文献   

6.
高山红景天形态分化与生存环境关系的研究   总被引:3,自引:1,他引:2  
对采自黑龙江省平顶山和吉林省长白山的14 个天然居群高山红景天的分株数、株高、基径、叶长和叶宽5 个形态性状进行了比较分析, 探讨了高山红景天适应环境的形态变异机制。单因素方差分析F 检验表明, 除分株数外的4 个形态性状在14 个居群中均表现为差异极显著。对这4 个性状的多重比较分析表明, 各形态性状在不同生态环境下表现出一定程度的分化。对14个天然居群形态性状的聚类分析表明, 高山红景天的形态变异与其生态环境间存在着明显的相关关系。  相似文献   

7.
Aims Crofton weed, with a subtropical origin, has successfully invaded in diverse habitats that belong to different climate zones in Southwest China. We tested whether local adaptation plays an important role in the successful invasion of crofton weed in heterogeneous environments.Methods Five populations from different habitats with an altitude ranging from 678 to 2356 m were selected. Plant height, biomass, seed yield and seed germination capability of these populations were investigated in the field. Greenhouse and reciprocal transplant experiments with the five populations were conducted, and all the above characters were measured and compared among these populations.Important findings Plant height, biomass, seed yield and seed germination rate were each significantly different among the five populations in field. However, there was no difference among these populations in the greenhouse experiment. In the reciprocal transplant experiment, plants from the five populations responded similarly to different habitats in the field, indicating lack of local adaptation. Instead, phenotypic plasticity likely plays a key role in the invasion success of crofton weed in different habitats.  相似文献   

8.
Mikael Ohlson 《Ecography》1989,12(1):46-53
The perennial herbaceous mire plant Saxifraga hirculus was grown for two years in a greenhouse under two nutrient regimes. Based on metric characters, primarily those associated with the potential for lateral spread, I found ecotypic differentiation both between plants originating from three adjoining but different habitats on one mire and between plants from three widely separated habitats. The fact that seeds from the different habitats germinated in different proportions after a first and second period of stratification. suggests that there is a habitat-specific, innate seeddormancy. Also the degree of phenotypic plasticity differed among the plants, viz. plants from the least fertile habitats exhibited the largest plasticity.  相似文献   

9.
Summary The responses of Polygonum pensylvanicum L., an early successional annual, and of Polygonum virginianum L., a late successional perennial, were examined along discontinuous gradients of soil moisture, light and nutrient availability. In the case of P. virginianum both individuals grown from seed and individuals grown from rhizomes were examined. The results show that variation in the response of individuals of a species of different age to environmental variation is as great as that found between the two congeneric species of different successional habitats. In general, individuals of the two species were more similar to one another in response to the resource gradients when both were started from seed, than were individuals of P. virginianum grown from seed and from rhizomes. Potential differences in stored reserves (starting capital) between rhizomes and seeds appeared to have little effect upon responses to resource availability. A number of plant characters were found to vary along the gradients in ways that were unique to the character, the gradient, and the age of the individual. These characters included aspects of leaf size, shape, and orientation, as well as whole plant architecture. Many if not all of these characters are likely to have significant effects upon the functioning of plants. The origin of this difference in response to the gradients of individuals of P. virginianum of differing age may be ontogenetic or may reflect differences in genetic composition created by recombination.  相似文献   

10.
朱旭  王静  孙克萍  江廷磊  姜云垒  冯江 《生态学报》2008,28(11):5248-5258
2007年在吉林省罗通山自然保护区,利用超声波探测仪(Avisoft-SASLAB PRO)录制并分析不同生境中马铁菊头蝠的回声定位声波。结果显示马铁菊头蝠在不同类型生境中活动;各生境中回声定位声波参数存在显著差异(one-way ANOVA,P〈0.05)。从环境因子中通过主成分分析筛选出与其回声定位声波相关的植被、气候和地形因子,探讨回声定位声波与这些因子的相关性。结果显示FM1和FM2带宽与乔木高(r=-0.948,-0.825;P〈0.05)、FM1起始频率和FM2终止频率与林冠面积(r=-0.967,-0.958;P〈0.05)、FM1起始频率、FM2终止频率和峰频与湿度(r=-0.776、-0.875和-0.794,P〈0.05)、脉冲持续时间和脉冲间隔与平均灌木高均呈显著负相关(r=-0.911,-0.990;P〈0.05),峰频与植被株数(r=0.756,P〈0.05)、脉冲持续时间与冠下高呈显著正相关(r=0.870,P〈0.05)。表明各种环境因子(植被因子、气候因子和地形因子)都在一定程度上影响回声定位声波,回声定位声波具有表型可塑性和生境适应性,这些特性决定了马铁菊头蝠生境利用的程度和可利用的资源。  相似文献   

11.
Zhu X  Wang J  Sun K P  Jiang T L  Jiang Y H  Feng J 《农业工程》2008,28(11):5248-5258
The present experiment was carried out in Luotong Mountain Natural Reserve in Jilin Province of China in 2007. We recorded and analyzed the echolocation calls of Rhinolophus ferrumequinum in different habitats by using Avisoft Bioacoustics USG 116 and Avisoft-SASLAB PRO (Avisoft Bioacoustics, Berlin, Germany). Our results showed that R. ferrumequinum foraged in diverse habitats in the study area, and their echolocation calls were significantly variable in different habitats (One-Way ANOVA, P < 0.05). Vegetative, climatic and topographical factors were selected by using the principal component analysis and the correlations between the parameters of echolocation calls and these environmental factors were analyzed. The results indicated that although R. ferrumequinum always emitted FM/CF/FM echolocation calls in different habitats, the parameters of echolocation calls varied with variable environmental factors. Significant negative correlation existed between FM1 bandwidth and arbor height (r = ?0.948, P < 0.05), FM2 bandwidth and arbor height (r = ?0.825; P < 0.05), FM1 starting frequency and canopy area (r = ?0.967, P < 0.05), FM2 ending frequency and canopy area (r = ?0.958, P < 0.05), FM1 starting frequency and air relative humidity (r = ?0.776, P < 0.05), FM2 ending frequency and air relative humidity (r = ?0.875, P < 0.05), peak frequency and air relative humidity (r = ?0.794, P < 0.05), pulse duration and average shrub height (r = ?0.911, P < 0.05), and inter-pulse interval and average shrub height (r = ?0.990, P < 0.05). Significant positive correlation existed between peak frequency and number of plants (r = 0.756, P < 0.05), and pulse duration and height below the canopy (r = 0.870, P < 0.05). Our results suggested that many kinds of ecological factors (such as vegetation factor, climatic factor and topographical factor) affected the structure of echolocation calls and made them diverse in different habitats, i.e., echolocation calls of bats had phenotypic flexibility and eco-adaptability. These characteristics determined the degree of available habitats and natural resources for R. ferrumequinum.  相似文献   

12.
Most obligate seeder species build up a soil seed bank that is associated with massive seed germination in the year immediately after a fire. These species are also shade‐intolerant and disappear when vegetation cover closes, creating unsuitable conditions for seedling recruitment. The only way for these plants to expand their populations is when habitats suitable for seedling recruitment arise (i.e. in years immediately after a fire). However, short primary seed dispersal of obligate seeders does not allow these plants to colonise the suitable habitats, and these habitats can only be colonised by secondary seed dispersion. We hypothesised that Fumana ericoides, an obligate‐seeding small shrub, not only establishes abundantly in the first year after fire, but also expands its local range in the following years due to secondary dispersal by ants while suitable habitats are still available. We tested this hypothesis using experimental studies and a simulation model of potential population expansion in a recently burned area. Results showed that F. ericoides not only established prolifically in the year immediately after fire, but was also able to recruit new individuals and expand its population in the years following the fire, despite a low germination rate and short primary seed dispersal. Ant‐mediated seed dispersal and availability of suitable habitats were key factors in this phenomenon: ants redistributed seeds in suitable habitats while they were available, which accelerated the expansion of F. ericoides because new plants established far away from the core population.  相似文献   

13.
铝胁迫对蓼科植物生长和光合、蒸腾特性的影响   总被引:2,自引:0,他引:2  
刘强  尹丽  龙婉婉  肖宜安 《广西植物》2011,31(2):227-232
采用水培试验,设置5种铝处理浓度,研究了铝对3种蓼科植物酸模叶蓼、杠板归和辣蓼叶片光合、蒸腾和叶绿素荧光参数的影响。结果表明,高铝处理(400μmol.L-1)显著抑制3种蓼科植物地上部和根系生长,并且导致3种蓼科植物叶片叶绿素含量、Chla/Chlb、净光合速率(Pn)、水分利用效率(WUE)、PSII光合电子传递量子效率(φPSII)和光化学猝灭系数(qP)显著下降。中低铝处理(25~100μmol.L-1)时,与对照相比,酸模叶蓼生物量显著增加,杠板归显著减少,辣蓼先增加后减少。其中,酸模叶蓼和辣蓼叶绿素含量、Chla/Chlb、Pn、蒸腾速率(Tr)、胞间CO2浓度(Ci)、PSII最大光化学效率(Fv/Fm)、qP均未发生显著变化,但辣蓼WUE、φPSII和非光化学猝灭系数(NPQ)显著下降,酸模叶蓼无显著变化;而杠板归除Ci、Fv/Fm外,其余叶片光合、蒸腾及叶绿素荧光参数均出现显著下降。上述结果表明,酸模叶蓼在中低铝处理条件下可通过保持较高的叶绿素含量、Chla/Chlb、WUE、Pn、PSII反应中心光化学反应效率以及提高非辐射能量耗散来增强其对铝的耐性。  相似文献   

14.
扎龙湿地芦苇分株生态可塑性及其对土壤因子的响应   总被引:1,自引:0,他引:1  
焦德志  于欣宇  王昱深  潘林  杨允菲 《生态学报》2019,39(11):4149-4157
扎龙湿地的芦苇既可形成大面积的单优群落,也可形成不同群落斑块。采用大样本抽样调查与统计分析方法,对湿地内水生生境、湿生生境、旱生生境和盐碱生境芦苇种群分株高度和生物量进行比较。结果表明,6—10月份,4个生境芦苇种群分株高度及生物量均以水生生境最高,盐碱生境最低,水生生境株高为盐碱生境的1.5—2.3倍,分株生物量为2.0—5.1倍,生境间的差异性以及差异序位均相对稳定。4个生境株高生境间变异系数(19.45%—31.56%)均高于生境内变异系数(8.07%—17.61%),分株高度在生境间的可塑性更大;分株生物量中水生生境、湿生生境和盐碱生境3个生境间的变异系数(33.43%—55.61%)均低于生境内变异系数(44.85%—79.82%),分株生物量在生境内的可塑性更大。不同生境条件下芦苇种群分株,在生长和生产上均存在较大的生态可塑性,表现出明显的环境效应,其中土壤含水量是该地区芦苇分株生态可塑性变异的主要驱动因子(R0.80),为正向驱动。  相似文献   

15.
This paper examines morphological plasticity of clonal plants of contrasting habitats and of contrasting architectures in response to nutrient supply. The hypotheses were tested that plants from rich habitats possess greater plasticity in response to variation in resource supply than species from poor habitats, and that rhizomatous species are less plastic in their response than stoloniferous species. Two sympodial rhizomatous herbs (Carex flacca, C. hirta) and two monopodial stoloniferous herbs (Trifolium fragiferum, T. repens) were subjected to four levels of nutrient supply in a garden experiment. One of the two species of each genus (C. hirta, T. repens) is from fertile and the other from infertile habitats. We measured 1) whole plant characters: total plant dry weight, number of modules (product of a single apical meristem) and number of ramets; 2) ramet characters: ramet leaf area and ramet height; and 3) spacer characters: branches per module, length per module and length per module internode.All measured characters in the Trifolium species significantly responded to treatment: the values for all measured characters increased with higher levels of fertilization. The differences in plant characters between fertilization levels were larger in Trifolium repens than in T. fragiferum in terms of whole plant characters, ramet characters and stolon internode length. The two Carex species did not differ in their responses to treatment in terms of most characters measured. In ramet characters and in some whole plant characters the species from fertile habitats were more plastic than those from infertile habitats. In spacer characters this pattern was not found. Foraging could not be demonstrated unequivocally.Morphological plasticity in the stoloniferous (Trifolium) species was much larger than in the rhizomatous (Carex) species. This seems in accordance with a foremost storage function of rhizomes, as against a foremost explorative function of stolons.  相似文献   

16.
Two groups of Plantago species, one of relatively nutrient-rich habitats (Plantago major L., P. major L. ssp. pleiosperma Pilger and P. martrima L.) and the other of relatively nutrient poor habitats (P. lanceolata L., P. media L. and P. coronopus L.), were compared with respect to the response of the plants to alterations of the level of mineral nutrition. The comparison deals with growth response and root cell membrane functions (Ca2+ and Mg2+ stimulated ATPases and lipids). As far as these parameters are concerned species from relatively nutrientpoor habitats are not much affected by bringing the plants to high-salt conditions, while the reverse was true for species from relatively nutrient-rich habitats when transferred to low salt medium.  相似文献   

17.
利用扫描电子显微镜(SEM)和树脂铸型法对东北地区10种李属植物导管分子类型、纹孔式、穿孔板类型的微形态结构特征进行了观察,并测量管腔长度、宽度、尾端长度及端壁斜度角的量化数据。结果显示:在不同生境下该属同种植物的导管类型、尾端长度与穿孔板类型较为稳定。所观察的李属植物存在3种导管类型:螺纹、孔纹、网纹导管。除山杏、欧李、东北李3种植物中仅存在网纹与孔纹2种类型的导管外,其余7种植物普遍存在3种类型导管。螺纹加厚在该属导管分子中普遍存在。单穿孔板在李属所观察植物中普遍存在,仅在黑樱桃、毛樱桃和郁李中发现梯状穿孔板。仅在稠李、东北李、郁李及山杏中观察到相对原始的对列—互列同时存在的纹孔式,其余6种均为互列式纹孔式。根据结构分析,认为东北地区10种李属植物中,郁李最为原始,欧李最为进化。同时,发现管腔长度、宽度与端壁面积与生境显著相关。在对尾端长度测量发现,同种植物导管分子的尾端长度在不同生境下长度较为稳定,几乎没有变化,可作为微观植物分类学的分类依据。  相似文献   

18.
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   

19.
Naturally occurring inland salt habitats are highly threatened due to increasing fragmentation and area reduction, while the surroundings of former potash mining dumps have experienced a massive invasion by halophytes over the last 20 years. We reconstructed colonisation patterns of these purely anthropogenic inland salt sites using molecular markers in the obligate halophyte Suaeda maritima (L.) dumort. (Chenopodiaceae), a typical plant in such areas. In the present study, 120 individual plants from 40 coastal and inland populations in Central Europe were subjected to AFLP analysis with nine primer combinations. A total of 243 AFLP band positions were scored as presence/absence characters. Genetic diversity values were not significantly different in populations from natural and anthropogenic inland salt sites as compared to coastal habitats. Results from principal coordinate analysis, neighbour-joining analysis and analysis of molecular variance ( amova ) all indicated that most of the genetic variation is preserved within populations, while genetic differentiation among populations is comparatively low. We conclude that S. maritima has repeatedly and independently colonised the surroundings of former potash mining dumps in Central Germany. However, the absence of founder effects and the lack of phylogeographic structure prevented us from identifying putative donor populations.  相似文献   

20.
Substantial ambiguity exists regarding the phylogenetic status of facultatively psychrophilic luminous bacteria identified as Photobacterium phosphoreum, a species thought to be widely distributed in the world's oceans and believed to be the specific bioluminescent light-organ symbiont of several deep-sea fishes. Members of the P. phosphoreum species group include luminous and non-luminous strains identified phenotypically from a variety of different habitats as well as phylogenetically defined lineages that appear to be evolutionarily distinct. To resolve this ambiguity and to begin developing a meaningful knowledge of the geographic distributions, habitats and symbiotic relationships of bacteria in the P. phosphoreum species group, we carried out a multilocus, fine-scale phylogenetic analysis based on sequences of the 16S rRNA, gyrB and luxABFE genes of many newly isolated luminous strains from symbiotic and saprophytic habitats, together with previously isolated luminous and non-luminous strains identified as P. phosphoreum from these and other habitats. Parsimony analysis unambiguously resolved three evolutionarily distinct clades, phosphoreum, iliopiscarium and kishitanii. The tight phylogenetic clustering within these clades and the distinct separation between them indicates they are different species, P. phosphoreum, Photobacterium iliopiscarium and the newly recognized 'Photobacterium kishitanii'. Previously reported non-luminous strains, which had been identified phenotypically as P. phosphoreum, resolved unambiguously as P. iliopiscarium, and all examined deep-sea fishes (specimens of families Chlorophthalmidae, Macrouridae, Moridae, Trachichthyidae and Acropomatidae) were found to harbour 'P. kishitanii', not P. phosphoreum, in their light organs. This resolution revealed also that 'P. kishitanii' is cosmopolitan in its geographic distribution. Furthermore, the lack of phylogenetic variation within 'P. kishitanii' indicates that this facultatively symbiotic bacterium is not cospeciating with its phylogenetically divergent host fishes. The results of this fine-scale phylogenetic analysis support the emerging view that bacterial species names should designate singular historical entities, i.e. discrete lineages diagnosed by a significant divergence of shared derived nucleotide characters.  相似文献   

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