Représentation pollinique actuelle à la limite des arbres au Nouveau-Québec

1991 ◽  
Vol 28 (4) ◽  
pp. 643-648 ◽  
Author(s):  
K. Gajewski
Keyword(s):  
Cluster Analysis ◽  
Principal Coordinates Analysis ◽  
Forest Tundra ◽  
Alnus Crispa ◽  
Modern Pollen ◽  
Vegetation Zones ◽  
Principal Coordinates ◽  
Shrub Tundra ◽  
Lichen Woodland

Modern pollen spectra from a series of lakes in northwestern Quebec reflect the major vegetation zones of the forest–tundra transition from latitude 55°N to 59°N. Shrub tundra samples are dominated by Betula and herb pollen, whereas Picea percentages are between 10 and 20%. Lichen woodland samples can contain over 60% Picea, with Betula and Alnus crispa each less than 20%. Pollen assemblages from the shrub subzone of the forest–tundra resemble those of the shrub tundra, while those from the forest subzone resemble lichen woodland samples. Maximum percentages of Alnus crispa are found in the forest–tundra. Classification of the samples using cluster analysis and an ordination by principal coordinates analysis suggest that densely and sparsely forested regions can be discriminated.

Vegetation and pollen relationships in eastern Canada

1993 ◽  
Vol 71 (2) ◽  
pp. 193-210 ◽  
Author(s):  
George A. King
Keyword(s):  
Cluster Analysis ◽  
Black Spruce ◽  
Spruce Forest ◽  
Eastern Canada ◽  
Forest Tundra ◽  
Surface Samples ◽  
Vegetation Zones ◽  
Pollen Types ◽  
Shrub Tundra ◽  
Lichen Woodland

The relationship between the vegetation and modern pollen assemblages in eastern Canada is summarized and analyzed using isopoll maps, ordination, and cluster analysis. The major vegetation zones are shrub tundra, forest tundra (divided into shrub and forest subzones), lichen woodland, closed black spruce forest, mixed boreal forest, and coastal barrens. The pollen assemblages of these zones are distinguished by differences in the relative abundance of a few important pollen types rather than by floristic differences. Northern zones have relatively high Cyperaceae and low Picea pollen percentages, and southern zones have high Picea and Abies pollen percentages. Surface samples from each vegetation zone generally form distinctive groups in the ordination analysis. However, samples from the shrub subzone of the forest tundra cluster with shrub tundra samples, and lichen woodland samples cluster with samples from the closed black spruce forest and the forest subzone of the forest tundra. Cluster analysis separates the samples into geographically distinct groups. However, these groups generally contain samples from several vegetation zones. The surface sample data set analyzed here will prove useful in reconstructing the vegetation history of the region. Key words: pollen surface samples, modern vegetation, eastern Canada.

scholarly journals Genetic Structure and Eco-Geographical Differentiation of Lancea tibetica in the Qinghai-Tibetan Plateau

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 97 ◽  
Author(s):  
Xiaofeng Chi ◽  
Faqi Zhang ◽  
Qingbo Gao ◽  
Rui Xing ◽  
Shilong Chen
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Gene Flow ◽  
Tibetan Plateau ◽  
Environmental Changes ◽  
Restricted Gene Flow ◽  
Principal Coordinates Analysis ◽  
Principal Coordinates ◽  
Genetic Diversity And Structure ◽  
Tanggula Mountains

The uplift of the Qinghai-Tibetan Plateau (QTP) had a profound impact on the plant speciation rate and genetic diversity. High genetic diversity ensures that species can survive and adapt in the face of geographical and environmental changes. The Tanggula Mountains, located in the central of the QTP, have unique geographical significance. The aim of this study was to investigate the effect of the Tanggula Mountains as a geographical barrier on plant genetic diversity and structure by using Lancea tibetica. A total of 456 individuals from 31 populations were analyzed using eight pairs of microsatellite makers. The total number of alleles was 55 and the number per locus ranged from 3 to 11 with an average of 6.875. The polymorphism information content (PIC) values ranged from 0.2693 to 0.7761 with an average of 0.4378 indicating that the eight microsatellite makers were efficient for distinguishing genotypes. Furthermore, the observed heterozygosity (Ho), the expected heterozygosity (He), and the Shannon information index (I) were 0.5277, 0.4949, and 0.9394, respectively, which indicated a high level of genetic diversity. We detected high genetic differentiation among all sampling sites and restricted gene flow among populations. Bayesian-based cluster analysis (STRUCTURE), principal coordinates analysis (PCoA), and Neighbor-Joining (NJ) cluster analysis based on microsatellite markers grouped the populations into two clusters: the southern branch and the northern branch. The analysis also detected genetic barriers and restricted gene flow between the two groups separated by the Tanggula Mountains. This study indicates that the geographical isolation of the Tanggula Mountains restricted the genetic connection and the distinct niches on the two sides of the mountains increased the intraspecific divergence of the plants.

scholarly journals Efficiency of RAPD and ISSR markers in assessing genetic diversity and relationships in black gram (Vigna mungo L. Hepper) vari

2010 ◽  
Vol 90 (4) ◽  
pp. 443-452 ◽  
Author(s):  
T. Karuppanapandian ◽  
H W Wang ◽  
T. Karuppudurai ◽  
J. Rajendhran ◽  
M. Kwon ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Genetic Relationships ◽  
Random Amplified Polymorphic Dna ◽  
Vigna Mungo ◽  
Polymorphic Band ◽  
Black Gram ◽  
Principal Coordinates Analysis ◽  
Principal Coordinates ◽  
Rapd And Issr

The DNA fingerprinting methodologies, random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR), were used to estimate genetic diversity and relationships among 20 black gram (Vigna mungo L. Hepper) varieties. Thirty selected RAPD primers amplified 255 bands, 168 of which were polymorphic (66.5%). On average, these primers produced 8.5 bands, 5.6 of which were polymorphic. Polymorphic band number varied from 2 (A-05) to 10 (OPA-02), with sizes ranging from 100 to 2550 bp. Twenty-four selected ISSR primers produced 238 amplified products, 184 of which were polymorphic (77.8%). On average, these primers generated 9.8 bands, with 7.7 polymorphic bands ranging in number from 4 (ISSR-13) to 11 (ISSR-03), and size from 100-2650 bp. Genetic relationships were estimated using similarity coefficient (Jaccard’s) values between different accession pairs; these varied from 30.7 to 85.0 for RAPD, and from 37.2 to 88.4 with ISSR. UPGMA analysis indicated that the varieties ranged in similarity from 0.50 to 1.00 (mean of 0.75) for RAPD, and from 0.47 to 1.00 (mean of 0.76) with ISSR. Cluster analysis of RAPD and ISSR results identified three clusters with significant bootstrap values, which revealed greater homology between the varieties. Principal coordinates analysis also supported this conclusion. Among the black gram varieties, WBU-108 and RBU-38 were highly divergent, whereas LBG-648 and LBG-623 were genetically similar. The markers generated by RAPD and ISSR assays can provide practical information for the management of genetic resources and these results will also provide useful information for the molecular classification and breeding of new black gram varieties.Key words: Black gram, cluster analysis, genetic diversity, ISSR, molecular markers, RAPD

scholarly journals Fingerprinting of Vaccinium corymbosum cultivars using DNA of fruits

2014 ◽  
Vol 41 (No. 4) ◽  
pp. 175-184 ◽  
Author(s):  
M. Carvalho ◽  
M. Matos ◽  
V. Carnide
Keyword(s):  
Random Amplified Polymorphic Dna ◽  
Vaccinium Corymbosum ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Highbush Blueberry ◽  
Principal Coordinates Analysis ◽  
Principal Coordinates ◽  
Production And Consumption ◽  
Simple Sequence

  In recent years the production and consumption Vaccinium corymbosum has increased. Highbush blueberry cultivars are divided into three types, northern, intermediate and southern. The traditional methods for classification of highbush blueberry cultivars using morphological and flavour traits are largely unsuccessful, due to environmental influences. The genetic similarity of ten highbush blueberry cultivars was evaluated using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers from fruits and leaves. The DNA concentrations obtained in fruits and leaves were very similar and the band profiles observed in the two tissues were analogous with both molecular markers. RAPD analysis generated 144 bands, of which 112 were polymorphic (77.8%) in fruits and 141 bands of which 118 were polymorphic (83.7%) in leaves. In fruits, ISSR analysis produced 151 bands of which 127 were polymorphic (84.1%) and in leaves it produced 148 bands with 127 being polymorphic (85.8%). Dendrogram and principal coordinates analysis (PCO) analysis using the both markers results were concordant and a clear division of the types of highbush blueberry cultivars (northern and southern) into two distinct groups was verified.    

scholarly journals Genetic diversity of wild sunflower (Helianthus sp.) accessions with different tolerance to mid-stalk white rot

Genetika ◽  
2014 ◽  
Vol 46 (2) ◽  
pp. 331-342 ◽  
Author(s):  
Dragana Miladinovic ◽  
Ksenija Taski-Ajdukovic ◽  
Nevena Nagl ◽  
Branislav Kovacevic ◽  
Aleksandra Dimitrijevic ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Significance Test ◽  
White Rot ◽  
High Tolerance ◽  
Principal Coordinates Analysis ◽  
Wild Sunflower ◽  
Phylogenetic Relations ◽  
Principal Coordinates

Random amplified polymorphic DNA (RAPD) markers were used to detect polymorphism among accessions of wild sunflower species H?lianthus maximiliani, Helianthus tuberosus, Helianthus mollis and Helianthus rigidus with different tolerance to mid-stalk white rot and selection of potential markers for different levels of tolerance to this disease. Estimates of genetic variation showed that genetic diversity was equally distributed between Helianthus species and within them. Cluster analysis corresponded to the phylogenetic relations within the genus Helianthus. The results obtained by principal coordinates analysis (PCoA), where the first two principal coordinates accounted for 83.7% of total variation, perfectly coincided with the results of cluster analysis. Contingency coefficient significance test showed that most of the used primers generated bands associated with some level of tolerance or susceptibility to mid- stalk white rot. Furthermore, contingency analysis showed that primer C12 generated bands associated with resistance (100%) to mid-stalk white rot both in H. mollis and in all accessions, while primer X18 generated bands significantly associated with high tolerance (75%) in H. rigidus, H. mollis as well as in all tested accessions. The C15-600 bp locus was found to be significantly associated with high tolerance (75%) in all accessions, and medium tolerance (50%) in H. mollis.

scholarly journals Composition and diversity of psocid (Insecta: Psocoptera) taxocoenoses in forest ecosystems of the Abieti-fageta s. lat. zone in the Western Carpathian Mts.

2009 ◽  
Vol 55 (No. 4) ◽  
pp. 184-192 ◽  
Author(s):  
O. Holuša
Keyword(s):  
Cluster Analysis ◽  
Species Composition ◽  
Correspondence Analysis ◽  
Dominant Species ◽  
Forest Ecosystems ◽  
Forest Type ◽  
Detrended Correspondence Analysis ◽  
Vegetation Zones ◽  
Characteristic Species

Psocid (Psocoptera) taxocoenoses were studied in forest ecosystems of the Western Carpathian Mts. in 1997–2001. As a study frame, vegetation tiers (VT = altitudinal vegetation zones) of geobiocoenological or forest-typological system were used. Lower units of forest typological system (forest type complexes) were used for the classification of ecological conditions and the material found in forest ecosystems of <I>Abieti-fageta</I> s. lat. communities (5<sup>th</sup> fir-beech VT) was evaluated in detail. This VT is the most widespread in the regions under study (the Moravskoslezské Beskydy Mts., the Vsetínské vrchy Hills and Javorníky). 2,023 adults comprising 28 species were found in the 5<sup>th</sup> VT. <I>Caecilius burmeisteri</I> was found as eudominant species; <I>Philotarsus picicornis, Caecilius flavidus</I> and <I>Peripsocus subfasciatus</I> were found as dominant species. In natural geobiocoenoses with the level of naturalness 1 or 2, the following species were found: <I>Mesopsocus unipunctatus, Caecilius flavidus</I>, and <I>Caecilius burmeisteri</I> as eudominant and <I>Caecilius despaxi</I> as dominant. Taxocoenoses of psocids were evaluated by Detrended Correspondence Analysis (DCA) and Divisive Cluster Analysis (DvClA). The axes were interpreted in DCA-analysis as follows: the <I>x</I>-axis denotes the influence of VTs and the <I>q</I>-axis refers to the influence of hydricity. This material was compared with other material obtained from various vegetation tiers in the Western Carpathians Mts. The characteristic species composition of psocids in the 5<sup>th</sup> VT was as follows: <I>Caecilius flavidus – C. burmeisteri – C. despaxi – Metylophorus nebulosus – Philotarsus picicornis</I>.

Stomate and pollen content of lake surface sediments from across the tree line on the Taimyr Peninsula, Siberia

1996 ◽  
Vol 74 (7) ◽  
pp. 1009-1015 ◽  
Author(s):  
S. L. Clayden ◽  
L. C. Cwynar ◽  
G. M. MacDonald
Keyword(s):  
Taimyr Peninsula ◽  
Data Set ◽  
Picea Obovata ◽  
Forest Tundra ◽  
Modern Pollen ◽  
Vegetation Zones ◽  
Forest Sites ◽  
Pollen Content ◽  
Pollen Rain ◽  
Components Analysis

Surface-sediment samples from 23 lakes on the Taimyr Peninsula were collected along a transect from tundra to forest and analyzed for their pollen and coniferous stomate content. Larix sibirica, the dominant tree in forest–tundra and forest vegetation zones, is poorly represented in the pollen spectra, never exceeding 8%. To examine the correspondence between the modern pollen rain and the vegetation zones of tundra, forest–tundra, and forest, a principal components analysis was applied to the pollen percentages. Betula and Alnus account for the greatest variance in the data set, and the set of tundra sites farthest north is distinct from the forest sites farthest south. Stomates of L. sibirica are present in all samples from sites where Larix trees are present, and some samples contained higher concentrations of stomates than pollen of Larix. Picea obovata stomates are found less consistently and less abundantly than Larix stomates.

Dendrobium speciosum (Dendrocoryne: Orchidaceae) complex in north Queensland

2006 ◽  
Vol 19 (3) ◽  
pp. 259 ◽  
Author(s):  
Peter B. Adams ◽  
Jacinta M. Burke ◽  
Sheryl D. Lawson
Keyword(s):  
Cluster Analysis ◽  
Multivariate Analysis ◽  
Morphological Variation ◽  
Taxonomic Study ◽  
Principal Coordinates Analysis ◽  
New Variety ◽  
Southern Group ◽  
Medium Length ◽  
Principal Coordinates ◽  
Small Overlap

Dendrobium speciosum Sm. has received insufficient taxonomic study north of St Lawrence, Queensland, where plants display much morphological variation in diverse habitats. Two varieties have been described previously, variety pedunculatum, occurring north of Townsville, and variety curvicaule for plants between the Connors Range south of Mackay and Annan River, south of Cooktown. In this multivariate analysis of 107 representative plants sampled from areas between St Lawrence and Cooktown, cluster analysis and principal coordinates analysis, were used to categorise the variation. Three overlapping varieties are revealed. North of Townsville variety pedunculatum intergrades with a medium-to-tall rainforest form, which separates with a small overlap in analyses from variety curvicaule plants south of Townsville. We formally describe these rainforest forms, previously referred to as variety curvicaule, as a new variety, Dendrobium speciosum variety boreale, which occurs between Cooktown and Mt Elliot, south of Townsville. Variety boreale is characterised by the presence of a collum in most individuals, medium to long pseudobulbs, large, wide leaves, long pedicels, and fairly uniform off-white to cream flowers. Dendrobium speciosum variety curvicaule Bailey is shown to be a name of uncertain application, and is neotypified to apply to the southern group of north Queensland plants, which occur between St Lawrence and Mt Dryander and on the Whitsunday Islands. Variety curvicaule is characterised by pseudobulbs that are of medium length, wide base and have an inconspicuous collum. The flowers have relatively wide segments in relation to all other varieties, long wide petals and incurving lateral sepals.

scholarly journals Psocid taxocenoses structure and diversity (Insecta: Psocoptera) in the forest ecosystems of the Piceeti–fageta s. lat. zone in the Western Carpathian Mts.

2011 ◽  
Vol 59 (5) ◽  
pp. 95-104 ◽  
Author(s):  
Otakar Holuša
Keyword(s):  
Cluster Analysis ◽  
Species Composition ◽  
Correspondence Analysis ◽  
Dominant Species ◽  
Forest Ecosystems ◽  
Forest Type ◽  
Detrended Correspondence Analysis ◽  
Vegetation Zones ◽  
Characteristic Species

Psocid taxocenoses (Psocoptera) were studied in forest ecosystems of the Western Carpathian Mts. during 1997–2001. As a study frame, vegetation tiers (= altitudinal vegetation zones) were used. Lower units of forest typological system (forest type complexes) were used for a classification of ecological conditions as well. Only a part of material, i.e. individuals that was found in the forest ecosystems of Piceeti-fageta s. lat. communities (= the 6th spruce-beech vegetation tier) was evaluated for purpose of this work. This vegetation tier is widespread in higher parts of mountains (the Moravskoslezské Beskydy Mts. and partly in the Oravské Beskydy Mts.). 554 adults comprising 17 species were found in total in the 6th vegetation tier. As eudominant species, the following ones were found: Caecilius despaxi, Caecilius burmeisteri, Mesopsocus unipunctatus, and Stenopsocus lachlani; as dominant species, the following ones were found: Caecilius flavidus and Reuterella helvimacula. In natural geobiocenoses with the level of naturalness of 1 or 2, the following species were found: as eudominant species: Mesopsocus unipunctatus, Stenopsocus lachlani, Caecilius despaxi, Amphigerontia bifasciata and Reuterella helvimacula. Dominant species was Caecilius burmeisteri and Caecilius flavidus. Taxocenoses of psocids were evaluated by Detrended Correspondence analysis (DCA) and Divisive Cluster analysis (DvClA). This material was compared to another material gained from various vegetation tiers in the Western Carpathians Mts. The characteristic species composition of psocids in the 6th vegetation tier was as follows – Cecilius despaxi – Stenopsocus lachlani – Mesopsocus unipunctatus – Reuterella helvimacula.

Neurophysiologic classification of Wilson's disease by using cluster analysis

2006 ◽  
Vol 37 (01) ◽  
Author(s):  
W Hermann ◽  
T Villmann ◽  
HJ Kühn ◽  
P Baum ◽  
G Reichel ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Wilson’S Disease ◽  
Wilson's Disease
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