A numerical taxonomic study of the British Phaeophyta

1975 ◽  
Vol 55 (4) ◽  
pp. 763-784 ◽  
Author(s):  
G. Russell ◽  
R. L. Fletcher
Keyword(s):  
Numerical Taxonomy ◽  
Taxonomic Study ◽  
Numerical Techniques ◽  
Marine Algal ◽  
Numerical Taxonomic Study

The principles and aims of numerical taxonomy were clearly stated by Sokal & Sneath (1963) and their procedures have since been adopted by many botanists working with numerous different groups of plants. Marine algal taxonomists, however, seem largely to have ignored these developments although Whitton (1969) has recommended that numerical techniques should be employed to help solve outstanding problems in the taxonomy of the Cyanophyta.

Numerical taxonomy of psychrotrophic bacteria isolated from raw ewes' milk

1993 ◽  
Vol 60 (3) ◽  
pp. 371-383 ◽  
Author(s):  
María-Rosario García-Armesto ◽  
Miguel Prieto ◽  
Carlos Alonso ◽  
María-Luisa GarcíLópez ◽  
María-Camino García-Fernández ◽  
...  
Keyword(s):  
Low Temperature ◽  
Aeromonas Hydrophila ◽  
Numerical Taxonomy ◽  
Taxonomic Study ◽  
Coagulase Negative Staphylococci ◽  
Gram Negative ◽  
Identification Schemes ◽  
Psychrotrophic Bacteria ◽  
Numerical Taxonomic Study ◽  
Reference Strains

SummaryA total of 204 psychrotrophic isolates from raw ewes' milk (hand and machine milked) were identified by conventional methods. In addition, a numerical taxonomic study was conducted on 180 of these isolates and 19 reference strains. Three of the isolates were yeasts. Using identification schemes, 54 isolates were assigned to genera of Gram-negative aerobic rods (Pseudomonas, Acinetobacter, Flavobacterium, MoraxellaandPsychrobacter), 48 were Enterobacteriaceae (Entero-bacter, Hafnia, Klebsiella, CitrobacterandSerratia) and one was identified asAeromonas hydrophila. The 98 Gram-positive isolates were identified asEnterococcus, Streptococcus, Leuconostoc, Lactococcus, Bacillus, Staphylococcus, Micrococcus, Aureobacterium, KurthiaandMicrobacterium. At the 82% similarity level (SSM), 18 clusters were formed. Cluster I included 34 strainsof Lactococcus, StreptococcusandLeuconostoc. Most of the 35 strains in cluster II wereEnterococcus. Clusters III and IV were identified asKurthiaandMicrobacteriumrespectively. Cluster V was identified asAureobacteriumand cluster VI consisted of coagulase-negative staphylococci. Gram-negative isolates formed 12 clusters:Aeromonas(one cluster), Enterobacteriaceae (two clusters),Flavobacterium(two clusters),PseudomonasandPsychrobacter immobilis(three clusters) andAcinetobacter(four clusters). Non-motile variants ofPs. fragiwere found.Enterococcusand Enterobacteriaceae did not have significant spoilage properties. As expected, Gram-negative aerobic rods were proteolytic and/or lipolytic even at low temperature. Contamination with certain types of psychrotrophs (Gram-negative aerobic rods and enterococci) seemed to be associated with the milking method. The isolate ofAes. hydrophilahad properties associated with virulence.

A numerical taxonomic study of variation in populations of Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae)

1978 ◽  
Vol 56 (1) ◽  
pp. 55-65 ◽  
Author(s):  
D. A. Chant ◽  
R. I. C. Hansell ◽  
H. Rowell
Keyword(s):  
Host Plants ◽  
Numerical Taxonomy ◽  
Morphological Characters ◽  
The Other ◽  
Climatic Variables ◽  
Taxonomic Study ◽  
Multivariate Tests ◽  
Morphological Variations ◽  
Numerical Taxonomic Study ◽  
Typhlodromus Caudiglans

Variation in morphological characters between Canadian populations of Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae) was examined by the methods of numerical taxonomy. Western populations are separated from the other populations when multivariate tests are used. Two subspecies are proposed, and Typhlodromella nodosus De Leon is synonymized with Typhlodromus caudiglans. Morphological variations between northern and eastern populations are correlated with climatic variables and with host plants.

scholarly journals Numerical taxonomic study of the genus Crotalaria L. (Crotalarieae, Fabaceae) in Nigeria

2018 ◽  
Vol 50 (1) ◽  
pp. 25-32
Author(s):  
Samaila Samaila Yaradua ◽  
Dhafer Ahmed Alzahrani ◽  
Abubakar Bello
Keyword(s):  
Cluster Analysis ◽  
Multivariate Analysis ◽  
Numerical Taxonomy ◽  
Field Work ◽  
Taxonomic Study ◽  
Cophenetic Correlation ◽  
Euclidian Distance ◽  
Ordination Analysis ◽  
Qualitative Characters ◽  
Numerical Taxonomic Study

Abstract Numerical taxonomic study of the genus Crotalaria L. in Nigeria was conducted to identify and differentiate some of the species of the genus Crotalaria using numerical taxonomy based on quantitative and qualitative characters. Field work was conducted, where different species were collected and analyzed using multivariate analysis. The results showed that all the collected species are distinct at Euclidian distance of 0.41 in the cluster analysis with Cophenetic correlation (r)=0.964. The ordination analysis based on the results of the PCA, separated the specimens into 7 groups corresponding to the result of cluster analysis. The first two components of the PCA account for 81.5%. The length of petiole, width of leaflet and length of fruit contributed more to showing delimitation among the species.

Implications of phenotypic plasticity for numerical taxonomy of Ornithogalum montanum (Liliaceae)

1991 ◽  
Vol 69 (1) ◽  
pp. 34-38 ◽  
Author(s):  
M. Pigliucci ◽  
M. G. Politi ◽  
D. Bellincampi
Keyword(s):  
Principal Component Analysis ◽  
Phenotypic Plasticity ◽  
Numerical Taxonomy ◽  
Natural Populations ◽  
Principal Component ◽  
Reaction Norm ◽  
Component Analysis ◽  
Morphological Response ◽  
Numerical Taxonomic Study ◽  
High Degree

Implications of phenotypic plasticity in a subspecific numerical taxonomic study of Ornithogalum montanum Cyr. (Liliaceae) are discussed. Clones belonging to six natural populations were grown in a glasshouse, and their morphological response to three water dosages was analyzed by means of principal component analysis. PC-1 ranks the three groups of replicated populations, suggesting a high degree of phenotypic plasticity; on the other hand, PC-3 is almost environmentally independent. Proximities in the phenetic space are shown to be at least partially environmentally dependent, suggesting a reaction norm for the character correlation matrix. The results do not corroborate a previous recognition of six subspecies of O. montanum. Key words: phenotypic plasticity, numerical taxonomy, Ornithogalum, reaction norm, principal component analysis.

A Numerical Taxonomic Study of Fucus Distichus (Phaeophyta)

1985 ◽  
Vol 65 (2) ◽  
pp. 433-459 ◽  
Author(s):  
E. L. Rice ◽  
A. R. O. Chapman
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Taxonomic Study ◽  
The North ◽  
Fucus Distichus ◽  
Cool Temperate ◽  
Specific Variation ◽  
Specific Rank ◽  
The North Atlantic ◽  
Numerical Taxonomic Study

The genus Fucus L. is widely distributed through the cool temperate waters of the north Atlantic and north Pacific oceans. The very large number of sub-generic taxa (> 100) previously recognized was reduced by Powell (1963) to only 6 species. In his revision, Powell recognized F. distichus L. emend. Powell as the most variable of these. He classified the intra-specific variation in this species into 4 sub-species: F. distichus distichus, F. distichus anceps (Harv. et Ward ex. Carruthers) Powell, F. distichus evanescens (C.Ag) Powell and F. distichus edentatus (Pyl.) Powell. Because of reports that intermediate forms existed in Iceland (Jonsson, 1903) and the Faeröes (Börgesen, 1902), Powell (1957 a,b) decided to use sub-specific status rather than specific designation for these 4 taxa. However, within North America the 4 sub-species of F. distichus were often assigned specific rank (e.g. Taylor, 1957).

scholarly journals A Numerical Taxonomic Study of Anaerobic Gram-negative Bacilli Classified as Bacteroides ureolyticus Isolated from Patients with Non-gonococcal Urethritis

Microbiology ◽  
1986 ◽  
Vol 132 (11) ◽  
pp. 3137-3146 ◽  
Author(s):  
E. A. R. Fontaine ◽  
T. N. Bryant ◽  
D. Taylor-Robinson ◽  
S. P. Borriello ◽  
H. A. Davies
Keyword(s):  
Taxonomic Study ◽  
Gram Negative ◽  
Gonococcal Urethritis ◽  
Numerical Taxonomic Study
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