scholarly journals Characterization of the vineyard byotyp collection of peach as step in prebreeding process

Genetika ◽  
2016 ◽  
Vol 48 (1) ◽  
pp. 349-362 ◽  
Author(s):  
Ivana Bakic ◽  
Vera Rakonjac ◽  
Dragan Nikolic ◽  
Milica Fotiric-Aksic ◽  
Slavica Colic ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Leaf Traits ◽  
Morphological Characterization ◽  
Fruit Colour ◽  
Flower Bud ◽  
Flesh Colour ◽  
Flower Type ◽  
High Degree

In this research, morphological characterization of vineyard peach collection was conducted. In 78 accessions thirty qualitative traits of tree, flower, leaf, fruit and stone were analysed by using UPOV and ECPGR descriptors. Most of the studied traits showed a high degree of variability. The lowest variability obtained for the leaf traits, and highest for skin and flesh colour. Not only were the accessions sorted into a large number of categories by the most of their properties, but also there was a significant level of variability in the collection, reflecting in the fact that the traits were recombinant in a different way. Principal component analysis (PCA) and a dendrogram were performed to determine relationships among accessions and to obtain information on the usefulness of those characters for the discrimination. The PCA revealed that the first 4 principal components were able to represent 43.1% of total variance. Traits with high discriminating values comprised internal and external fruit colour, flower type and colour, flower bud density and stone shape. The cluster analysis showed that the accessions were placed in three main clusters. The greatest impact on the separation in clusters had fruit over colour and extent of fruit over colour. Moreover, the collection can also comprise some accessions with the preferred recombination of properties that might be interesting for further studies in breeding.

scholarly journals Morphological characterization of eighteen lakes of the north and middle coast of Rio Grande do Sul, Brazil

2014 ◽  
Vol 26 (2) ◽  
pp. 199-214 ◽  
Author(s):  
Alois Eduard Schäfer ◽  
Cassiano Alves Marchett ◽  
Sabrina Maurer Schuh ◽  
Siclério Ahlert ◽  
Rosane Maria Lanzer
Keyword(s):  
Principal Component Analysis ◽  
Cluster Analysis ◽  
Discriminant Analysis ◽  
Trophic State ◽  
Principal Component ◽  
Rio Grande ◽  
Morphological Characterization ◽  
Relative Depth ◽  
Rio Grande Do Sul

AIMS: The present study aimed at a morphological characterization of 18 lakes of the municipalities of Cidreira, Balneário Pinhal and Palmares do Sul, situated in the northern and middle coastal plain of Rio Grande do Sul, Brazil. METHODS: The morphometric survey was conducted in the summer of 2011/2012, based on echo sounder coupled with GPS and the application of remote sensing and GIS procedures. The morphometric parameters used for the characterization were: surface area, perimeter, perimeter development, volume, relative fetch, maximum depth, average depth, relative depth, median depth of volume, length and width. The statistical interpretation included Test of Normality, Coefficient of Variation, Correlation and Regression Analysis, Cluster Analysis, Discriminant Analysis and Principal Component Analysis. RESULTS: Eighteen lakes were described and five of them are presented by aerial photo and bathymetric map. They represent the proposed morphological lake types. The calculation of the coefficient of variation revealed larger amplitudes of parameters related to lake size than to depth. The application and interpretation of cluster analysis, confirmed by discriminant analysis, distinguished those lakes in five morphological groups, which differ mainly by size and subsequently by depth. The Principal Component Analysis identified the first component with positively charged variables of size and negatively charged relative depth, and a second component with positive charge of maximum and average depths. CONCLUSIONS: The low relative depths and the exposure to constant northeastern winds reduce the transparency of the lakes. Consequently, they are light limited by suspension of inorganic and organic matter. A property that limits the application of trophic state indices. The high dynamic of the water bodies produces an oxygenated sediment surface that facilitates the settlement by aerobic organisms all over the bottom area. The shallowness and the low median depths of volume are limiting factors for sustainable water supply management. The morphological characteristics of the coastal lakes make very difficult an accurate ecological assessment based on usual trophic state criterions and a sustainable water resource management using general guidelines.

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.

Characterization of fretting wear experiments on spline couplings by principal component analysis

2016 ◽  
Vol 231 (7) ◽  
pp. 860-868 ◽  
Author(s):  
Waqar Qureshi ◽  
Francesca Cura ◽  
Andrea Mura
Keyword(s):  
Experimental Data ◽  
Principal Component Analysis ◽  
Principal Component ◽  
Component Analysis ◽  
Fretting Wear ◽  
Aircraft Industry ◽  
Surface Movement ◽  
Noisy Measurements ◽  
Quasi Static Process

Fretting wear is a quasi-static process in which repeated relative surface movement of components results in wear and fatigue. Fretting wear is quite significant in the case of spline couplings which are frequently used in the aircraft industry to transfer torque and power. Fretting wear depends on materials, pressure distribution, torque, rotational speeds, lubrication, surface finish, misalignment between spline shafts, etc. The presence of so many factors makes it difficult to conduct experiments for better models of fretting wear and it is the case whenever a mathematical model is sought from experimental data which is prone to noisy measurements, outliers and redundant variables. This work develops a principal component analysis based method, using a criterion which is insensitive to outliers, to realize a better design and interpret experiments on fretting wear. The proposed method can be extended to other cases too.

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