scholarly journals Morphological variation in Opuntia jaliscana (Cactaceae)

2017 ◽  
Vol 74 (1) ◽  
pp. 058
Author(s):  
Edgar Noel López-Borja ◽  
Rosa De Lourdes Romo-Campos ◽  
Hilda Julieta Arreola-Nava ◽  
Alejandro Muñoz Urias ◽  
Sofía Loza-Cornejo
Keyword(s):  
Discriminant Analysis ◽  
Morphological Variability ◽  
Fruit Size ◽  
Aridity Index ◽  
Wild Populations ◽  
Discriminant Functions ◽  
Morphological Variations ◽  
Quantitative Characters ◽  
Reproductive Characters ◽  
One Way Anova

The aim of this study was to describe morphological variations of Opuntia jaliscana in 5 wild populations in the state of Jalisco (Mexico). Populations were selected along an environmental aridity gradient, and 61 vegetative and reproductive characters from 25 individuals were measured per population. Quantitative characters were analyzed independently by a one-way ANOVA test using the site as variation factor. Subsequently, a discriminant analysis was performed. The discriminant analysis results showed that the 46% of the total variation was explained by the first four discriminant functions. The analysis of overall membership between populations indicated that individuals were correctly classified in 87% of cases. Pearson linear correlation between the most significant variables and the aridity index, showed a positive relationship to cladode thickness and diameter of the trunk. The population from Tierra Blanca shows an outlier behavior because of variation in cladode thickness and fruit size, which might be related to plasticity of individuals to have a greater availability of water, while in Los Vallejo the separation might be due to selection by management and use. The remaining populations exhibited some morphological variability without separation.

scholarly journals Morphological Variations of Wild Populations of Brycon dentex (Characidae, Teleostei) in the Guayas Hydrographic Basin (Ecuador). The Impact of Fishing Policies and Environmental Conditions

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1901
Author(s):  
Ana Gonzalez-Martinez ◽  
Carmen De-Pablos-Heredero ◽  
Martin González ◽  
Jorge Rodriguez ◽  
Cecilio Barba ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Environmental Conditions ◽  
Anthropogenic Activity ◽  
Freshwater Species ◽  
Fishing Pressure ◽  
Wild Populations ◽  
Morphometric Variation ◽  
Morphological Variations ◽  
Body Development ◽  
The Impact

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance.

scholarly journals Where should we draw the lines between dinocyst “species”? Morphological continua in Black Sea dinocysts

2019 ◽  
Vol 38 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Thomas M. Hoyle ◽  
Manuel Sala-Pérez ◽  
Francesca Sangiorgi
Keyword(s):  
Black Sea ◽  
Genetic Difference ◽  
Morphological Variability ◽  
Intraspecific Variability ◽  
Nutrient Status ◽  
The Black Sea ◽  
Genetic Sequencing ◽  
Morphological Variations ◽  
Intermediate Phenotypes ◽  
Primary Driver

Abstract. The morphology of dinoflagellate cysts (dinocysts) is related not only to the genetics of the motile dinoflagellate from which it derives, but is also dependent on a range of environmental factors including salinity, temperature and nutrient status. Although this knowledge improves our understanding of the drivers behind dinocyst morphological variations, it makes the taxonomy governing their description somewhat complex. In basins such as the Black Sea, where environmental change can be extreme and occurs on relatively short (millennial) timescales, taxonomy becomes particularly challenging. Morphological continua can be observed between described forms, displaying a large range of intermediate phenotypes that do not necessarily correspond to any genetic difference. As these morphological nuances may preserve information about palaeoenvironments, it is important to find a systematic method of characterising morphotypes. Here, we show a dinocyst matrix within which dinocysts are described according to their similarity to (or difference from) described forms based on key descriptive parameters. In the example set out here, cyst shape and degree of process and/or ectophragm development are taken as two key parameters in Pyxidinopsis psilata and Spiniferites cruciformis, and can allow the description of intermediate forms even though the definitions do not overlap. We review some frequently occurring morphotypes and propose that using matrices to show the gradual variation between endmember forms is the most pragmatic approach until cyst–theca studies and genetic sequencing can be used to demonstrate relationships between genotypes and morphotypes. As prior studies propose salinity to be a primary driver of intraspecific variability, the endmembers presented may represent salinity extremes within an overall brackish environment. Although we cannot assign each morphotype to a value or a range of an environmental parameter (e.g. salinity) as the different morphotypes can occur in the same sample, using this matrix allows preservation of information about morphological variability without creating taxonomic categories that are likely to require alteration if genetic evidence becomes available.

scholarly journals Morphological evaluation of common bean diversity in Bosnia and Herzegovina using the discriminant analysis of principal components (DAPC) multivariate method

Genetika ◽  
2013 ◽  
Vol 45 (3) ◽  
pp. 963-977 ◽  
Author(s):  
Jasmin Grahic ◽  
Fuad Gasi ◽  
Mirsad Kurtovic ◽  
Lutvija Karic ◽  
Mirha Djikic ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Common Bean ◽  
Bosnia And Herzegovina ◽  
Principal Components ◽  
Morphological Characteristics ◽  
Principal Component ◽  
Discriminant Functions ◽  
Factor Loadings ◽  
Geographical Regions ◽  
High Level

In order to analyze morphological characteristics of locally cultivated common bean landraces from Bosnia and Herzegovina (B&H), thirteen quantitative and qualitative traits of 40 P. vulgaris accessions, collected from four geographical regions (Northwest B&H, Northeast B&H, Central B&H and Sarajevo) and maintained at the Gene bank of the Faculty of Agriculture and Food Sciences in Sarajevo, were examined. Principal component analysis (PCA) showed that the proportion of variance retained in the first two principal components was 54.35%. The first principal component had high contributing factor loadings from seed width, seed height and seed weight, whilst the second principal component had high contributing factor loadings from the analyzed traits seed per pod and pod length. PCA plot, based on the first two principal components, displayed a high level of variability among the analyzed material. The discriminant analysis of principal components (DAPC) created 3 discriminant functions (DF), whereby the first two discriminant functions accounted for 90.4% of the variance retained. Based on the retained DFs, DAPC provided group membership probabilities which showed that 70% of the accessions examined were correctly classified between the geographically defined groups. Based on the taxonomic distance, 40 common bean accessions analyzed in this study formed two major clusters, whereas two accessions Acc304 and Acc307 didn?t group in any of those. Acc360 and Acc362, as well as Acc324 and Acc371 displayed a high level of similarity and are probably the same landrace. The present diversity of Bosnia and Herzegovina?s common been landraces could be useful in future breeding programs.

scholarly journals Using Linear Discriminant Analysis to Classify Snowfall Situations into Avalanching and Non-Avalanching Ones

1977 ◽  
Vol 19 (81) ◽  
pp. 679-680
Author(s):  
N.F. Drozdovskaya
Keyword(s):  
Discriminant Analysis ◽  
Statistical Methods ◽  
Training Sample ◽  
Dispersion Analysis ◽  
Snow Accumulation ◽  
Discriminant Functions ◽  
Prognostic Information ◽  
Individual Parameter ◽  
Linear Discriminant ◽  
Avalanche Forecasting

Abstract The existing methods of predicting avalanche danger often do not meet users’ demands because of the empiric character of the insufficient volume of information used. In such forecasts the contribution of each individual parameter into the prognostic information is unknown, and this is very important when studying such an event as avalanche formation, which is conditioned by a complex interaction of numerous factors, including snow accumulation, the state of snow thickness, and the conditions of its development. It is obvious that such problems can be successfully solved by statistical methods, and that explains the growing interest in numerical methods of avalanche forecasting. Problems of multi-dimensional observations arises in many scientific fields. The method suited for this problem is discriminant analysis, the purpose of which is to divide a multi-dimensional observation vector into predetermined classes. This study considers the prognostic (diagnostic) problems of fresh-snow avalanches released during snowfall or in the two days after it has ceased. The theoretical basis is a complex of statistical methods: correlation and dispersion analysis, “sifting" for the choice of predictors’ informative groups, construction of linear parametric discriminant functions, predictions based on training sample, and verification of discriminant functions based on independent material. The archive used in the study consisted of 500 avalanching cases and 1 300 non-avalanching ones. All situations were grouped according to geomorphological characteristics. Each situation is described by eight meteorological characteristics. The results of classification of snowfall situations into avalanching and non-avalanching ones are as follows: reliability of ρ is from 75% to 91%, H from 0.15 to 0.51; based on independent material the reliability of ρ is from 63% to 85%, H from 0.10 to 0.56. This paper has been accepted in revised form for publication in a later issue of the Journal of Glaciology.

Morphological variability in Fasciola hepatica eggs in ruminants, rodents and lagomorphs

1998 ◽  
Vol 72 (4) ◽  
pp. 313-317 ◽  
Author(s):  
M. Abrous ◽  
A.M. Comes ◽  
N. Gasnier ◽  
D. Rondelaud ◽  
G. Dreyfuss ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
The Netherlands ◽  
Analysis Of Variance ◽  
Fasciola Hepatica ◽  
Morphological Variability ◽  
Morphological Differences ◽  
Skewness And Kurtosis

AbstractThe length and width of 1297 Fasciola hepatica eggs shed in cattle hosts, 337 in sheep and 199 in nutria, were measured from several parts of France. The data were compared with those obtained from other studies in Spain, France (where rats were also investigated), Germany and the Netherlands. One way analysis of variance and discriminant analysis were used to assess differences between host origins. The distribution of length and width of eggs were analysed using skewness and kurtosis Fisher coefficients. The eggs recovered from sheep, cattle, rodents and lagomorphs were different in size: the eggs found in rodents (length L × width W in μm: 8592) and lagomorphs (L × W in μm: 9100) were smaller than those found in sheep and cattle (L×W in μm: 10,000). These morphological differences in F. hepatica eggs were host-induced in rats (L×W in μm: 9709 in cattle to 8949 in rats) and rabbits (L×W in μm: 9709 in cattle to 8432 in rabbits). These differences in size of eggs might correspond to their being less able to develop into miracidia in less frequent hosts such as rodents and rabbits.

scholarly journals Morphological variability of acorns and its taxonomic significance in Quercus. from Turkey

2015 ◽  
Vol 43 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Y Bakis ◽  
MT Babaç
Keyword(s):  
Principal Component Analysis ◽  
Morphological Variability ◽  
Morphological Characteristics ◽  
Principal Component ◽  
Component Analysis ◽  
Morphological Characters ◽  
Taxonomic Significance ◽  
Morphological Variations ◽  
Quercus Species ◽  
Different Populations

Morphological variations of acorn among and within the groups of Quercus species were studied. A total of 617 acorns belonging to 14 species representing all 3 sections of Quercus L. (Fagaceae) in Turkey were examined in this study. Specimens were collected from 47 different populations over both Anatolian and Thrace part of Turkey. Principal component analysis was used to analyze the morphological characteristics of acorns. Results obtained from this study demonstrate the use of morphological characters in differentiating the taxa of Quercus and Cerris sections studied. Another important finding is the introgression among the acorns of species within Quercus section DOI: http://dx.doi.org/10.3329/bjb.v43i3.21601 Bangladesh J. Bot. 43(3): 293-299, 2014 (December)

scholarly journals Karyological and morphological variations within the genus Dysphania (Chenopodiaceae) in Bulgaria

2013 ◽  
Vol 72 (1) ◽  
pp. 49-69 ◽  
Author(s):  
Neli H. Grozeva ◽  
Yanka G. Cvetanova
Keyword(s):  
Statistical Analysis ◽  
Chromosome Number ◽  
Quantitative Traits ◽  
Morphological Variability ◽  
Evolutionary Mechanisms ◽  
Qualitative Traits ◽  
Phenotype Variation ◽  
Morphological Variations ◽  
Interpopulation Variation ◽  
Generative Organs

AbstractThe karyological and morphological variability of species from the genus Dysphania were studied. The results demonstrated that genus Dysphania is represented in Bulgaria by five species: Dysphania ambrosioides, D. multifida, D. botrys, D. schraderiana and D. pumilio. The first two species are tetraploids with chromosome number 2n = 32 for D. ambrosioides and 2n = 36 for D. multifida. The remaining three species are diploids with 2n = 18. The results from statistical analysis demonstrated that the main source of phenotype variation in the species is the interpopulation variation. The specific characters which allowed their recognition are themorphological characteristics of the perianth lobes, the upper leaves and the seeds. The distinction between D. multifida, D. ambrosioides and D. schraderiana is based on differences in the quantitative traits, while in D. botrys and D. pumilio qualitative traits are also important. The basic evolutionary mechanisms are polyploidy and diploidy.Atendency towards reduction in the size of generative organs and the number of perianth lobes was found.

scholarly journals Asexual Reproduction of Phytophthora capsici as Affected by Extracts from Agricultural and Nonagricultural Soils

2007 ◽  
Vol 97 (7) ◽  
pp. 873-878 ◽  
Author(s):  
S. Sanogo
Keyword(s):  
New Mexico ◽  
Chemical Composition ◽  
Discriminant Analysis ◽  
Phytophthora Capsici ◽  
Organic Matter Content ◽  
Discriminant Functions ◽  
Chile Pepper ◽  
Soil Extracts ◽  
Significant Difference ◽  
History Of

Formation of sporangia and zoospores in species of Phytophthora is known to be influenced by soil microbial and chemical composition. In Phytophthora capsici, the study of the relationship of soil chemical composition to production of sporangia and zoospores has been limited. P. capsici is a soilborne pathogen of a wide array of vegetable crops, including chile pepper (Capsicum annuum) in New Mexico. Production of sporangia and zoospores by P. capsici was evaluated in extracts of soils from three different environments in New Mexico: (i) agricultural environments with a long history of chile pepper cropping and occurrence of P. capsici (CP), (ii) agricultural environments with no history of chile pepper cropping and no occurrence of P. capsici (Non-CP), and (iii) nonagricultural environments consisting of forests and rangelands (Non-Ag). There was a significant difference in production of P. capsici asexual propagules, expressed as natural log (number of sporangia × number of zoospores), among the three environments (P = 0.0298). Production of propagules was 9 to 13% greater in Non-Ag than in CP or Non-CP environments. Stepwise multiple discriminant analysis and canonical discriminant analysis identified the edaphic variables Na, pH, P, organic matter content, and asexual propagule production as contributing the most to the separation of the three environments. Two significant (P < 0.0001) canonical discriminant functions were derived with the first function, accounting for ≈75% of the explained variance. Based on the two discriminant functions, ≈93, 86, and 89% of observations in CP, Non-CP, and Non-Ag environments, respectively, were classified correctly. Soils from agricultural and nonagricultural environments differentially influence production of sporangia and zoospores in P. capsici, and soil samples could be effectively classified into agricultural and nonagricultural environments based on soil chemical properties and the production of asexual propagules by P. capsici in soil extracts.

scholarly journals A proposal for a new morphological classification of the popliteus muscle tendon with potential clinical and biomechanical significance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Łukasz Olewnik ◽  
Robert F. LaPrade ◽  
Friedrich Paulsen ◽  
Bartosz Gonera ◽  
Konrad Kurtys ◽  
...  
Keyword(s):  
Morphological Variability ◽  
Lower Limbs ◽  
Popliteus Tendon ◽  
Type I ◽  
Popliteofibular Ligament ◽  
Morphological Variations ◽  
Type Iv ◽  
Orthopedic Surgeons ◽  
Popliteus Muscle

AbstractThe purpose of this study was to characterize the morphological variations in the proximal attachments and create an accurate classification of the PPM for use in planning surgical procedures in this area, for evaluating radiological imaging and rehabilitation. One hundred and thirty-four lower limbs of body donors (52 woman and 82 man) fixed in 10% formalin solution were examined. The popliteus muscle was present in all 134 limbs. Four main types were identified with subtypes. The most common type was Type I (34.3%), characterized by a single tendon in the popliteus sulcus. Type II (30.6%) characterized by a main tendon in the popliteus sulcus and accessory bands. This type was divided into five subtypes (A–E) based on presence of specific accessory bands. Type III (15.3%) was characterized by two tendons in the popliteal sulcus. Type IV (19.4%) was characterized by two tendons in the popliteus sulcus and additional bands. This type was also divided into five subtypes (A–E) based on presence of specific accessory bands. The popliteofibular ligament was present in 90.3% of cases. A new classification based on a proximal attachment is proposed. The popliteus tendon is characterized by a very high morphological variability, which can affect posterolateral knee stability and the natural rotation of the tibia. Such a classification system may be useful for clinicians performing medical procedures within the knee joint, including orthopedic surgeons.

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