Genetic and environmental contributions to multivariate morphological pattern in Puccinellia (Poaceae)

1988 ◽  
Vol 66 (12) ◽  
pp. 2436-2444 ◽  
Author(s):  
Jerrold I. Davis
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Morphological Characters ◽  
Morphological Pattern ◽  
The North ◽  
Two Samples ◽  
Environmental Component ◽  
Components Analysis ◽  
Complex Variation ◽  
Plastic Components

The contributions of genetic and environmental variation to multivariate patterns in morphology were investigated in a comparative analysis of two samples of plants representing the Puccinellia nuttalliana complex (Poaceae). The first sample is a series of individuals (genotypes) collected live, vegetatively divided, and grown under controlled environmental conditions. Phenotypic variation in this sample, in individual characters and in multivariate factors, can be apportioned between genetic (among genotype) and environmental (among treatment) causes. The second sample consists of field-collected individuals from throughout the North American range of the complex. Variation in this sample, as in most field-collected samples, cannot be assigned directly to its underlying causes. Multivariate patterns in the two samples were analyzed by identical principal-components analyses of 48 morphological characters. The strongest factor identified by the greenhouse principal-components analysis correlates with the strongest of the field principal-components analysis; they are similar in character makeup, both reflecting spikelet size and plant scabrousness. These factors have a genetic component and no environmental component and appear to differentiate Puccinellia distans from the rest of the complex. The second strongest factor of the greenhouse principal-components analysis correlates with the second of the field principal-components analysis. These axes reflect general vegetative stature; they have genetic and plastic components. The overall analysis indicates that multivariate patterns in phenotype can reflect both genetic and environmental effects, in varying proportions; patterns of genetic affinity therefore may be difficult to dissociate from those reflecting plasticity.

Gradient analysis of remnant True and Upper Coastal Prairie grasslands of North America

1988 ◽  
Vol 66 (11) ◽  
pp. 2152-2161 ◽  
Author(s):  
David D. Diamond ◽  
Fred E. Smeins
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Andropogon Gerardii ◽  
Schizachyrium Scoparium ◽  
Response Curves ◽  
Coastal Prairie ◽  
Species Response ◽  
The North ◽  
Precipitation Decrease ◽  
Components Analysis

Sixty-three upland True and Upper Coastal Prairie grasslands were sampled for vegetation composition and soil variables. The first axis from principal components analysis produced a south to north arrangement of stands along which temperature and precipitation decrease and soil organic matter increases (P < 0.0001). The second principal components analysis axis was related to a soils gradient, primarily within Texas communities, which had more varied soils than grasslands to the north. Species response curves against the first axis showed a continual replacement from north to south, with Schizachyrium scoparium and Paspalum plicatulum dominants in the south, Andropogon gerardii more important in central and northern communities, and Stipa spartea and Sporobolus heterolepis important in the north. The C3/C4 ratio of grasses increased rapidly northward from Nebraska. Species diversity and richness did not vary greatly and showed nonsignificant correlations with environmental variables across this latitudinal gradient. Stand relationships from cluster analysis corresponded with the results of principal components analysis, and based on these analyses, plus a review of the literature, seven community types were recognized. Five form a continuum, across which Andropogon gerardii increases northward and Schizachyrium scoparium increases southward, while two are limited to high-precipitation areas of north Texas.

Carex xueyingiana (Cyperaceae), a new species from Hainan Island, China

Phytotaxa ◽  
2017 ◽  
Vol 308 (2) ◽  
pp. 239
Author(s):  
HAIJUN YANG ◽  
HAN XU ◽  
YUNFEI DENG ◽  
YIDE LI
Keyword(s):  
Cluster Analysis ◽  
New Species ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Hainan Island ◽  
Morphological Characters ◽  
Components Analysis ◽  
A New Species

A new species of Carex (Cyperaceae), Carex xueyingiana, from section Radicales, is described and illustrated from Hainan Island, China. We analyzed 35 morphological characters using Cluster Analysis and Principal Components Analysis to evaluate the relationships between the new species and the 15 species from the same section occurring in China. The new species is similar to C. chlorocephalula, displaying pubescent rhizomes, leaves densely hispidulous on both surfaces, and slender tufted culms. Carex xueyingiana differs from C. chlorocephalula by the leaves distinctly longer than culms (not equaling these), stems 4–6 mm wide (instead 1–3 mm), bracts sheath-like, 5–6 mm long (instead leaf-like and 2–3.5 cm long), spikes 7–10 mm long (instead 10–15 mm), and perigynium beakless (instead beaked). The new species is only known from Hainan Island and is assessed as Vulnerable (VU DD).

An Examination of the Reliability and Validity of the Breskin Rigidity Scale

1996 ◽  
Vol 82 (1) ◽  
pp. 195-198 ◽  
Author(s):  
John Maltby ◽  
Christopher Alan Lewis
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Reliability And Validity ◽  
Attitude Inventory ◽  
Two Samples ◽  
Components Analysis ◽  
Item Scale ◽  
Reliability Coefficients

The present study examined the reliability and validity of the 15-item Breskin Rigidity Scale. Two samples of UK adults ( n = 216; n = 277) completed the rigidity scale alongside the Wilson-Patterson Attitude Inventory and the trait measure of the Sandler-Hazari Obsessionality Inventory. Satisfactory reliability coefficients were obtained for the rigidity scale in both samples. A principal components analysis of the 15-item rigidity scale showed that 13 items loaded on the first component and 2 on a second component. These items were removed and the reliability and validity estimates were recalculated. Comparisons were drawn between the original and amended versions. The amended 13-item scale shows an improved reliability and higher association with other measures of rigidity and rigid character.

The Analysis of Interregional Differentiation and Constructing Ratings of Development of Russian Regions

2005 ◽  
pp. 54-75 ◽  
Author(s):  
S. Baranov ◽  
T. Skufina
Keyword(s):  
Quantitative Analysis ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Socioeconomic Development ◽  
Russian Regions ◽  
The North ◽  
Interregional Differentiation ◽  
Components Analysis

The article proposes methods for quantitative analysis of interregional differentiation structure and construction of regional ratings based on principal components analysis. Results of computations and analysis of interregional differentiation structure for all Russia, the North zone, and Russia without the North zone are provided. For computations data for 1998-2003 and their forecasting values for 2004-2005 were used. Ratings of socioeconomic development of Russian regions for 1998-2005 are also provided in the paper.

Phenotypic plasticity and contrasting habitat colonization in Festuca pallescens

1993 ◽  
Vol 71 (7) ◽  
pp. 970-977 ◽  
Author(s):  
Gabriel Oliva ◽  
Arturo Martínez ◽  
Marta Collantes ◽  
Jorge Dubcovsky
Keyword(s):  
Phenotypic Plasticity ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Widespread Species ◽  
Southern Patagonia ◽  
Spikelets Per Panicle ◽  
Habitat Colonization ◽  
Components Analysis ◽  
Festuca Pallescens ◽  
Plastic Components

Eight populations of Festuca pallescens (Poaceae) from southern Patagonia (Argentina) were chosen to test whether their morphology and anatomy were associated with climatic and edaphic characteristics of their habitats and to discriminate genetic and plastic components of the variation. Fourteen environmental variables were measured to characterize eight localities. Cluster analysis classified them into four habitats. Principal components analysis based on 22 morphological and anatomical characters of five individuals from each population was performed. This ordination grouped them by habitat. Small plants with a low number of spikelets were found in the xeric habitat, whereas plants of the saline habitat showed a significantly higher number of spikelets. Large plants were characteristic of the humid habitats, but at higher elevations of foothill humid valleys the plants produced few spikelets per panicle with larger lemmas and heavier propagules than those in the coastal humid plains. A larger sample of 10 populations drawn from across the distribution of F. pallescens showed that seed collected at high altitudes were significantly heavier then those collected near sea level. The same characters were measured again 1 year after transplanting to uniform conditions. Significant differences between habitats disappeared. These data showed that phenotypic plasticity allows for diverse habitat colonization of this widespread species. Key words: Gramineae, phenotypical plasticity, seed weight, principal components analysis, ecotypes.

Diagnoses Generated by Numerical Taxonomic Methods Applied to Standard Blood Variables

1980 ◽  
Vol 19 (04) ◽  
pp. 205-209
Author(s):  
L. A. Abbott ◽  
J. B. Mitton
Keyword(s):  
Liver Cirrhosis ◽  
Renal Disease ◽  
Principal Components Analysis ◽  
Discriminant Function ◽  
Principal Components ◽  
Discriminant Function Analysis ◽  
Chronic Renal Disease ◽  
Function Analysis ◽  
Infectious Hepatitis ◽  
Components Analysis

Data taken from the blood of 262 patients diagnosed for malabsorption, elective cholecystectomy, acute cholecystitis, infectious hepatitis, liver cirrhosis, or chronic renal disease were analyzed with three numerical taxonomy (NT) methods : cluster analysis, principal components analysis, and discriminant function analysis. Principal components analysis revealed discrete clusters of patients suffering from chronic renal disease, liver cirrhosis, and infectious hepatitis, which could be displayed by NT clustering as well as by plotting, but other disease groups were poorly defined. Sharper resolution of the same disease groups was attained by discriminant function analysis.

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