scholarly journals The flowerpiercers interactions with a community of high Andean plants

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jairo Andrés Cuta-Pineda ◽  
Luis Alejandro Arias-Sosa ◽  
Roxibell C. Pelayo
Keyword(s):  
Interaction Network ◽  
Principal Component ◽  
Niche Overlap ◽  
Floral Traits ◽  
Nectar Robbing ◽  
Morphometric Traits ◽  
Nectar Production ◽  
Pollen Transport ◽  
Andean Plants ◽  
The Stability

Abstract Background Flowerpiercers (Diglossa) are traditionally considered as “parasites” of the pollination processes, as they can access the nectar without entering in contact with the reproductive structures of the plants. Nevertheless, the effect of flowerpiercers seems to vary according to their behavior and the flower’s traits. So, in this work, we aimed to explore the floral characteristics that may determine the susceptibility to robbing and pollen transport by flowerpiercers. Also, we identified the potential types of interactions and studied interaction network properties. Methods We collected the information of 16 ornithophilic plants regarding their floral traits and robbing frequency. Also, we captured 4 species of flowerpiercers and evaluated pollen transport (frequency and loads). We tested the correlation between floral traits, robbing frequency, and pollen transportation. Later, we used these variables in a cluster and principal component analyses to identify the potential types of interactions. Finally, we analyzed and compared the structure of the plants-flowerpiercers interaction network. Results Nectar production significantly influenced both nectar robbing and pollen transportation. While the corolla length was only correlated to the robbing susceptibility. Also, we found that particular flowerpiercers species transported higher loads of some plant pollen, which can be related to the differences in behavior and morphometric traits. We proposed the classification of five different types of plant-flowerpiercer interactions, that showed different potential mutualist or antagonist relations based on the affectation of nectar robbing and the service of pollen transportation. The interaction networks consisted of 49 links, with 2.4 links per species, and presented indicators of a medium to high resilience, stability, and resistance (nestedness, connectance, and robustness). Also, the network presented medium to low specialization and substantial niche overlap. Conclusions The ecological role of the flowerpiercers goes beyond its classic assignation as “parasites” as they can actively transport pollen of several Andean plants, affecting its evolutionary history and the stability of the systems.

scholarly journals Multivariate analysis as a tool for measuring the stability of morphometric traits in Lycopersicon plants from in vitro culture

2000 ◽  
Vol 23 (2) ◽  
pp. 479-493 ◽  
Author(s):  
Guillermo Pratta ◽  
Roxana Zorzoli ◽  
Liliana Amelia Picardi
Keyword(s):  
Multivariate Analysis ◽  
In Vitro Culture ◽  
Principal Component ◽  
Eigenvalues And Eigenvectors ◽  
Morphometric Traits ◽  
Regenerated Plants ◽  
Phenotypic Structure ◽  
Regeneration Cycle ◽  
The Stability

The phenotypic stability of morphometric traits in Lycopersicon spp. (stem perimeter at the base, middle and top, and number of flowers per cluster) was measured by multivariate analysis through a progeny test in order to estimate the genetic stability of these traits. Principal components were calculated for two groups of Lycopersicon spp., non-regenerated plants and the progeny of regenerated plants. Analysis of variance was performed to support principal component analysis. Both groups presented similar eigenvalues and eigenvectors, while no significant differences were found between any of the traits studied. These results indicated that the phenotypic structure was the same among the progeny of regenerated and non-regenerated plants, so that no variation would occur in in vitro culture. Multivariate analysis proved to be an appropriate methodology for the measurement of the stability of morphometric traits after one regeneration cycle.

Applications of random graphs

2017 ◽  
Author(s):  
A.C.C. Coolen ◽  
A. Annibale ◽  
E.S. Roberts
Keyword(s):  
Social Networks ◽  
Random Graphs ◽  
Interaction Network ◽  
Power Grids ◽  
Protein Protein Interaction ◽  
Topological Features ◽  
First Case ◽  
The Stability ◽  
Protein Protein Interaction Network

This chapter reviews graph generation techniques in the context of applications. The first case study is power grids, where proposed strategies to prevent blackouts have been tested on tailored random graphs. The second case study is in social networks. Applications of random graphs to social networks are extremely wide ranging – the particular aspect looked at here is modelling the spread of disease on a social network – and how a particular construction based on projecting from a bipartite graph successfully captures some of the clustering observed in real social networks. The third case study is on null models of food webs, discussing the specific constraints relevant to this application, and the topological features which may contribute to the stability of an ecosystem. The final case study is taken from molecular biology, discussing the importance of unbiased graph sampling when considering if motifs are over-represented in a protein–protein interaction network.

Morph-specific correlations between floral traits in a distylous Ophiorrhiza napoensis (Rubiaceae) population in southern China

2001 ◽  
Vol 17 (5) ◽  
pp. 719-728 ◽  
Author(s):  
HIROSHI KUDOH ◽  
TAKASHI SUGAWARA ◽  
SUGONG WU ◽  
JIN MURATA
Keyword(s):  
Southern China ◽  
Principal Component ◽  
Corolla Tube ◽  
Floral Traits ◽  
Evergreen Forest ◽  
Tube Length ◽  
Multiple Traits ◽  
Floral Trait ◽  
Subtropical Evergreen Forest ◽  
Positive Correlations

Floral trait correlations were compared between the two flower morphs of a distylous Ophiorrhiza napoensis population in a subtropical evergreen forest at the Defu Natural Animal Preserve, Guangxi, China. Common principal component analyses indicated that overall patterns in correlations among floral traits were morph specific in the study population. Strong positive correlations (r > 0.9) between anther height and corolla-tube length were found in both morphs. Stigma height correlated positively with corolla-tube length in the long-styled morph (r = 0.843), but not in the short-styled morph (r = −0.018). Flower-morph-specific correlation suggests that natural selection by pollinators has moulded trait covariance among floral traits. Because morph-specific correlations are expressed as the patterns of within-morph variation among multiple traits, putative genes responsible for the stigma-corolla tube correlation should not link to the supergene for sex-organ reciprocity between the morphs, but their expression is limited in the long-styled morph.

Morphological differentiation in African catfish (Clarias gariepinus) from three different populations in Nigeria

2021 ◽  
Vol 16 (1) ◽  
pp. 13-20
Author(s):  
Popoola Omoniyi Michael ◽  
Olagunju Oluwatosin Olubunmi
Keyword(s):  
Clarias Gariepinus ◽  
Morphological Differentiation ◽  
Principal Component ◽  
Individual Species ◽  
African Catfish ◽  
Morphometric Traits ◽  
Meristic Characters ◽  
High Positive Correlation ◽  
Meristic Counts ◽  
Major Cluster

AbstractIntraspecific morphological variation in Clarias gariepinus was studied in three water bodies. Twenty-three morphometric characteristics and seven meristic were used. Principal component (PC) analysis showed that morphometric traits of River Osun and Ogbese were somewhat related while that of Aago showed no relatedness, there were no difference among the meristic counts of the populations. PC1, and PC2 accounted for 93% and 4% of the variation observed in the populations. High positive correlation was observed in Aago (r = 0.872, b = 2.10) and Ogbese population while low correlation and negative allometric growth (r = 0.425 and b= 1.38) was observed in Asejire population. Cluster analysis revealed that three studied populations are separated into two major clusters, with samples from Asejire and Ogbese population found within the same cluster but different sub- clusters, similarly some of samples from Aago were also within the same cluster while samples 10 were found on a separate and major cluster. The study confirms the variability among individual species within each population, indicates the presence of genetic diversity among the populations of C. gariepinus and the Pre-anal distance and dorsal fin ray count could be employed in the identification of populations of catfish. Key words: morphometric traits, meristic characters, populations, allometric

scholarly journals Analysis of field-grown Panax ginseng rhizosphere microbiome provides clues for preventing red skin root syndrome

2021 ◽  
Author(s):  
Xingbo Bian ◽  
Ling Dong ◽  
Yan Zhao ◽  
He Yang ◽  
Yonghua Xu ◽  
...  
Keyword(s):  
Biological Control ◽  
Ecological Niche ◽  
Interaction Network ◽  
Pathogenic Fungi ◽  
Niche Overlap ◽  
Amplicon Sequencing ◽  
Soil Improvement ◽  
Niche Separation ◽  
Key Factors ◽  
Rhizosphere Microbiome

Abstract Background Ginseng red skin root syndrome (GRS) is one of the most common ginseng diseases. It leads to a severe decline in ginseng quality and seriously affects the ginseng industry in China. However, as a root disease, the characteristics of GRS rhizosphere microbiome are still unclear. Methods The amplicon sequencing technology, combined with bioinformatics analysis, was used to explore the relationship between soil ecological environment and GRS. Results There were significant differences in the diversity and richness of soil microorganisms between the rhizosphere with different degrees of disease, especially between healthy ginseng (HG) and heavily diseased groups. We also found that bacterial communities underwent multiple changes between complex stability and simple instability in different ginseng rhizospheres through the established interaction networks. The GRS group also had more competition with each other and ecological niche separation than the HG group. The fungal community's stability decreased significantly in the early stages of the disease, followed by the formation of a stable and complex fungal community. The GRS groups significantly increased interspecies cooperation and ecological niche overlap in the fungal network than the HG group. Microbes closely related to potential pathogenic fungi were also identified according to the interaction network, which provided clues for looking for biological control agents. Finally, the Distance-based redundancy analysis (dbRDA) results indicated that total P (TP), available K (AK), available P (AP), catalase (CAT), invertase (INV) are the key factors that influence the microbial communities. Conclusions This study collectively analyzed the changing characteristics in ginseng rhizosphere and provided the basis for soil improvement and biological control of field-grown ginseng.

scholarly journals Stability of Wheat Genotypes by AMMI and Yield Evaluated under Peninsular Zone of India

2021 ◽  
Author(s):  
Ajay Verma ◽  
G.P. Singh
Keyword(s):  
Weighted Average ◽  
Principal Component ◽  
Efficient Estimation ◽  
High Yield ◽  
First Year ◽  
Wheat Genotypes ◽  
Stability Measure ◽  
Linear Behaviour ◽  
The Stability ◽  
Selection Of

Background: Efficient estimation of main and interaction effects under multi environment trials had been carried out by AMMI. Studies with low proportion of the variance explained by first interaction principal component IPCA1 under AMMI analysis had been reported biased interpretation for the stability of the genotypes.Methods: Weighted Average of Absolute scores (WAASB), quantitative stability measure had been recommended for selection of productive genotypes with broad adaptation. The selection of promising genotypes had been assisted by use of superiority index (WAASBY) that considered simultaneous use of yield and stability by allowing variable weighting mechanism for yield and stability.Result: Wheat GW509 and HI1633 genotypes had been identified by stability measure WAASB for the first year. While Superiority index considered stability and high yield settled for HI1633 and Raj4083 genotypes. Analytic measures of adaptability PRVG and MHPRVG observed suitability of HI1633 and Raj 4083. SI expressed positive linear behaviour with yield, MHPRVG and PRVG measures. While stability measure WAASB maintained moderate negative correlation with yield, SI, MHPRVG and PRVG. Wheat genotypes HI1633, HI1641 and HI1646 identified by stability measure for the next year of study. Superiority index selected HI1641, HI1633 and MACS6752 genotypes. SI expressed direct linear relation with yield, MHPRVG and PRVG. Stability measure exhibited indirect relationships with SI, MHPRVG, PRVG and yield Wheat genotypes HI1633, Raj 4083 for first year and HI1641, MACS6752 for the second year of study.

scholarly journals Dynamic population stage structure due to juvenile–adult asymmetry stabilizes complex ecological communities

2021 ◽  
Vol 118 (21) ◽  
pp. e2023709118
Author(s):  
André M. de Roos
Keyword(s):  
Self Regulation ◽  
Interaction Network ◽  
Population Level ◽  
Stage Structure ◽  
Current Theory ◽  
Species Interaction ◽  
Interaction Matrix ◽  
Foraging Efficiency ◽  
Ecological Communities ◽  
The Stability

Natural ecological communities are diverse, complex, and often surprisingly stable, but the mechanisms underlying their stability remain a theoretical enigma. Interactions such as competition and predation presumably structure communities, yet theory predicts that complex communities are stable only when species growth rates are mostly limited by intraspecific self-regulation rather than by interactions with resources, competitors, and predators. Current theory, however, considers only the network topology of population-level interactions between species and ignores within-population differences, such as between juvenile and adult individuals. Here, using model simulations and analysis, I show that including commonly observed differences in vulnerability to predation and foraging efficiency between juvenile and adult individuals results in up to 10 times larger, more complex communities than observed in simulations without population stage structure. These diverse communities are stable or fluctuate with limited amplitude, although in the model only a single basal species is self-regulated, and the population-level interaction network is highly connected. Analysis of the species interaction matrix predicts the simulated communities to be unstable but for the interaction with the population-structure subsystem, which completely cancels out these instabilities through dynamic changes in population stage structure. Common differences between juveniles and adults and fluctuations in their relative abundance may hence have a decisive influence on the stability of complex natural communities and their vulnerability when environmental conditions change. To explain community persistence, it may not be sufficient to consider only the network of interactions between the constituting species.

scholarly journals Principal Component Analysis of Morphometric Traits of West African Dwarf Goats

2019 ◽  
Vol 1 ◽  
pp. 26-32 ◽  
Author(s):  
I O Dudusola ◽  
S O Oseni ◽  
M A Popoola ◽  
A Jenyo
Keyword(s):  
Principal Component Analysis ◽  
Body Weight ◽  
Total Variation ◽  
Age Groups ◽  
Principal Component ◽  
Component Analysis ◽  
West African ◽  
Age Group ◽  
Morphometric Traits ◽  
West African Dwarf

The study was conducted to evaluate the principal component analysis of phenotypic attributes of West African Dwarf (WAD) goat. Data collected on the live body weight and twelve morphometric traits of the goats which were categorised into four age groups based on their dentition. The age groups were: less than 2years old, 2- 3years old, 3-4 years old and 4 years old. The data were subjected to a PCA and Cluster analyses using the multivariate procedure components of SAS (2003). Result revealed that highest values of morphometric traits were obtained in goats that of 4 years old. The rate of increase in body weight and other morphometric traits was high in age group of ˂2 years to age 2-3years compared to differences observed in others across the age group. Heart Girth had the highest correlation with body weight. Foreleg, neck, ear and hind leg lengths; wither height and rump height were weakly correlated with the body weight of the goats. Result revealed that two Principal components were retained in the first age group (age group˂2years) which accounted for 72.99% of the total variation. The first PC alone accounted for 63.13% of the total variation while PC2 accounted for the remaining 9.86%. From this study, it was concluded that there is interdependence among body weight and morphometric traits and that morphometric traits can be used in predicting live weight of WAD goats; PCA and Cluster could be exploited in breeding and selection programmes to acquire highly coordinated animal bodies using fewer measurements.

Heuristic Principal Component Analysis-Based Unsupervised Feature Extraction and Its Application to Bioinformatics

2015 ◽  
pp. 138-162 ◽  
Author(s):  
Y-H. Taguchi ◽  
Mitsuo Iwadate ◽  
Hideaki Umeyama ◽  
Yoshiki Murakami ◽  
Akira Okamoto
Keyword(s):  
Principal Component Analysis ◽  
Feature Extraction ◽  
Principal Component ◽  
Component Analysis ◽  
Circulating Microrna ◽  
Biomarker Identification ◽  
Typical Situation ◽  
Aberrant Dna Methylation ◽  
The Stability ◽  
Unsupervised Feature Extraction

Feature Extraction (FE) is a difficult task when the number of features is much larger than the number of samples, although that is a typical situation when biological (big) data is analyzed. This is especially true when FE is stable, independent of the samples considered (stable FE), and is often required. However, the stability of FE has not been considered seriously. In this chapter, the authors demonstrate that Principal Component Analysis (PCA)-based unsupervised FE functions as stable FE. Three bioinformatics applications of PCA-based unsupervised FE—detection of aberrant DNA methylation associated with diseases, biomarker identification using circulating microRNA, and proteomic analysis of bacterial culturing processes—are discussed.

scholarly journals Hybridization and hybrid zone stability between two lizards explained by population genetics and niche quantification

2020 ◽  
Vol 190 (2) ◽  
pp. 757-769
Author(s):  
Imanol Cabaña ◽  
Margarita Chiaraviglio ◽  
Valeria Di Cola ◽  
Antoine Guisan ◽  
Olivier Broennimann ◽  
...  
Keyword(s):  
Hybrid Zone ◽  
Parental Species ◽  
Niche Overlap ◽  
Analysis Framework ◽  
Nuclear Marker ◽  
Lizard Species ◽  
New Models ◽  
Species Evolution ◽  
Main Factors ◽  
The Stability

Abstract Understanding the factors that affect hybridization is an important issue in the study of species evolution. In this work, we analyse the genetic structure of two lizard species, Salvator merianae and Salvator rufescens, at a microscale within a climatic niche analysis framework, to reveal the main factors that contribute to the stability of their hybrid zone. We assess the effect of climate in hybridization by quantifying and decomposing the niche overlap of both species. Using a mitochondrial and a nuclear marker, we find that hybridization is frequent and is not restricted to the sympatric region. The gene flow is mainly from S. rufescens to S. merianae, with introgression into the range of S. merianae. Also, S. merianae would have long been present in the area, while S. rufescens appears to be a recent colonizer. The climate contributes to the population structure of S. merianae, but not to that of S. rufescens. The niches occupied by S. rufescens in the hybrid zone and the non-hybrid zone are similar, while the niches of S. merianae are different. Our results do not fit previous models of hybrid zone stability, suggesting the need to develop new models that consider the evolutionary factors that can differentially affect parental species and hybrids.

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