scholarly journals GENETIC DIVERSITY IN AMBURANA (Amburana cearensis) ACCESSIONS: HIERARCHICAL AND OPTIMIZATION METHODS

2021 ◽  
Vol 45 ◽  
Author(s):  
Ana Valéria Vieira de Souza ◽  
Jackson Rafael de Sá Carvalho ◽  
Evelyn Sophia Silva Costa ◽  
Cristina Soares de Souza ◽  
Herick Fernando de Jesus Silva ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Material ◽  
Optimization Methods ◽  
Optimization Method ◽  
Inter Simple Sequence Repeat ◽  
Clustering Methods ◽  
Discrimination Power ◽  
Genetic Patterns ◽  
Linkage Method ◽  
Issr Molecular Markers

ABSTRACT The evaluation of accessions in a germplasm bank is essential for determining the potential parents in conservation programs, especially for native trees. This study aimed to determine the genetic diversity among 68 Amburana cearensis genotypes from different locations in the state of Pernambuco, Brazil. Their genetic patterns were evaluated by Inter Simple Sequence Repeat (ISSR) molecular markers and genetic divergence was evaluated through multivariate analyses using different clustering methods. The optimization method used (Tocher) was in agreement with all the hierarchical models used, in which clustering of the genotypes occurred similarly, specifically for the accession BB116, which is an important genetic material to be preserved and studied. Among the various hierarchical methods applied, the Average Linkage method exhibited higher discrimination power, allowing identification of a larger number of divergent groups, thus implying wide genetic diversity among A. cearensis accessions.

scholarly journals Estimates of genetic divergence in cowpea by multivariate analysis in different environments

2019 ◽  
Vol 35 (6) ◽  
Author(s):  
Larissa Pereira Ribeiro ◽  
Jeniffer Santana Pinto Coelho Evangelista ◽  
Michelle Brandão Damacena ◽  
Arthur Mayrink Elizeu ◽  
Igor Ferreira Coelho ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Multivariate Analysis ◽  
Genetic Variability ◽  
Agronomic Traits ◽  
Optimization Methods ◽  
Clustering Methods ◽  
Mato Grosso ◽  
Genetic Potential ◽  
Pod Length ◽  
Mato Grosso Do Sul

Cowpea is a legume of great importance in the Brazilian nutrition, mainly in the Northeast region. Despite the low yield of Brazilian cowpea, the species presents a genetic potential to be explored. Thus, this work aimed to characterize the genetic diversity of cowpea genotypes by agronomic traits and select genotypes for possible crosses by multivariate analysis. Four value for cultivation and use tests were carried out with cowpea genotypes in 2005 and 2006, in the municipalities of Aquidauana, Chapadão do Sul, and Dourados, in the state of Mato Grosso do Sul. The experimental design was a complete randomized block with 20 genotypes and four replications. The evaluated traits were value for cultivation, plant lodging, pod length, grain weight of five pods, number of grains per pod, pod weight, severity of powdery mildew, and grain yield. To estimate the genetic diversity among the genotypes, the optimization methods of Tocher and UPGMA were used. The generalized distance of Mahalanobis was used as a dissimilarity measure. The clustering methods revealed genetic variability among the cowpea genotypes evaluated. The methods used formed a different number of groups for each environment. Genotypes TE97-309G-24, MNC99-542F-5, BRS Paraguaçu, BRS Paraguaçu, BR 17-Gurguéia, and CNC x 409-11F-P2 can be used to obtain promising combinations and high genetic variability.

scholarly journals Genetic diversity in apple tree cultivars established in the Sierra de Arteaga, Coahuila, Mexico

2018 ◽  
Vol 5 (13) ◽  
pp. 65
Author(s):  
Mayra Alejandra Escobar Saucedo ◽  
Cristobal Aguilar ◽  
Antonio Vázquez Ramos ◽  
Manuel Humberto Reyes Valdés ◽  
Raúl Rodríguez Herrera
Keyword(s):  
Genetic Diversity ◽  
Genetic Risk ◽  
Simple Sequence Repeat ◽  
Apple Tree ◽  
Inter Simple Sequence Repeat ◽  
Apple Cultivars ◽  
Apple Production ◽  
Issr Molecular Markers ◽  
Simple Sequence ◽  
Issr Primers

Apple production in the Sierra de Arteaga, Coahuila is mainly based on the Golden Delicious cultivar. Production based on only a few cultivars represents a genetic risk, because if they are susceptible to a pest, disease or climate change much of this production would be lost if one or more of these conditions occurred. Foreseeing this situation, farmers have introduced different commercial apple cultivars, but there is little information about the genetic diversity among them. Therefore, the aim of this study was to estimate the rates of intraspecic genetic diversity of 12 different apple cultivars using inter-simple sequence repeat (ISSR) molecular markers. Employing nine ISSR primers, it was possible to identify 124 DNA bands, of which 63% were polymorphic, with genetic diversity of 0.24. Results suggest that these cultivars are adapted to the region's climate and can be utilized to increase the overall plantation area, in order not to depend on a single cultivar.

scholarly journals APPLICATIONS OF ISSR MARKERS IN STUDIES OF GENETIC DIVERSITY OF Pityrocarpa moniliformis

2020 ◽  
Vol 33 (4) ◽  
pp. 1017-1024
Author(s):  
FRANCIVAL CARDOSO FELIX ◽  
KYVIA PONTES TEIXEIRA DAS CHAGAS ◽  
CIBELE DOS SANTOS FERRARI ◽  
FÁBIO DE ALMEIDA VIEIRA ◽  
MAURO VASCONCELOS PACHECO
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Genetic Distance ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Shannon Index ◽  
Resolving Power ◽  
Development Programs ◽  
Diversity Studies ◽  
Issr Molecular Markers

ABSTRACT Pityrocarpa moniliformis (Benth.) Luckow & R. W. Jobson (Fabaceae) is a native brazilian species with high potential for economic development programs in semiarid regions, mainly related to the production of honey, animal food and firewood. Thus, the objective of this work was to select Inter-Simple Sequence Repeat (ISSR) molecular markers for genetic diversity studies, as well as to test the efficiency of this approach in quantifying the genetic diversity of a natural P. moniliformis population. For this, 28 ISSR molecular markers were tested, evaluating the total number of loci, polymorphism rate and the Polymorphism Information Content (PIC) for the selected primers, the “Marker Index”, and the “Resolving Power”. Genetic diversity parameters (Nei genetic distance and Shannon index) were evaluated for 30 individuals located in Macaíba, Rio Grande do Norte State, Brazil. Seven primers were selected, which provided 74 loci, with 82% being polymorphic, while the PIC value was 0.344. The Nei genetic distance was 0.244, and the Shannon index was 0.374. Therefore, ISSR molecular markers (UBC 827, 840, 844, 857, 859, 860 and 873) are considered efficient in studying the genetic diversity of populations for the selection of matrices and germplasm banks, and may contribute to the conservation and genetic improvement of P. moniliformis populations.

scholarly journals Genetic Relatedness among Cultivars of the Greek Plum Germplasm

2013 ◽  
Vol 41 (2) ◽  
pp. 491 ◽  
Author(s):  
Ioannis ATHANASIADIS ◽  
Nikolaos NIKOLOUDAKIS ◽  
Marianna HAGIDIMITRIOU
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Genetic Background ◽  
Genetic Relatedness ◽  
Germplasm Collection ◽  
Prunus Domestica ◽  
Discrimination Power ◽  
Breeding Programs ◽  
Issr Molecular Markers ◽  
Rapd And Issr

Genetic diversity of the Greek plum germplasm collection was investigated using a combined RAPD and ISSR molecular markers approach. Twenty-six genotypes held at NAGREF-Naoussa were analyzed, producing in total 150 loci, of which 116 were polymorphic. Both techniques were highly informative and had a discrimination power greater than 0.9. RAPD and ISSR dendrograms were fairly correlated. The accessions were clustered according to ploidy and species. All Prunus domestica genotypes were grouped together and showed greater similarity to P. insititia and P. cerasifera genotypes compared to P. salicina, which was found genetically diverged. Bayesian structural analysis revealed significant admixture among genotypes. Greek varieties P. domestica ‘Goulina’ and ‘Asvestochoriou’ exhibited a distinctive genetic background, differentiating them from foreign varieties. This feature could make them attractive for breeding programs, since they can increase genetic diversity.

Genetic diversity of Symplocos paniculata of Hunan province revealed by inter-simple sequence repeat (ISSR)

2019 ◽  
Vol 51 (5) ◽  
Author(s):  
Huifang Cao ◽  
Qiang Lin ◽  
Peiwang Li ◽  
Jingzhen Chen ◽  
Changzhu Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Simple Sequence Repeat ◽  
Inter Simple Sequence Repeat ◽  
Hunan Province ◽  
Sequence Repeat ◽  
Simple Sequence

scholarly journals Influence of environmental factors on the genetic variation of the aquatic macrophyte Ranunculus subrigidus on the Qinghai-Tibetan Plateau

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhigang Wu ◽  
Xinwei Xu ◽  
Juan Zhang ◽  
Gerhard Wiegleb ◽  
Hongwei Hou
Keyword(s):  
Genetic Diversity ◽  
Tibetan Plateau ◽  
Environmental Factors ◽  
Local Adaptation ◽  
Aquatic Macrophyte ◽  
Spatial Genetic Structure ◽  
Long Distance ◽  
Elevation Gradients ◽  
Mantel Tests ◽  
Genetic Patterns

Abstract Background Due to the environmental heterogeneity along elevation gradients, alpine ecosystems are ideal study objects for investigating how ecological variables shape the genetic patterns of natural species. The highest region in the world, the Qinghai-Tibetan Plateau, is a hotspot for the studies of evolutionary processes in plants. Many large rivers spring from the plateau, providing abundant habitats for aquatic and amphibious organisms. In the present study, we examined the genetic diversity of 13 Ranunculus subrigidus populations distributed throughout the plateau in order to elucidate the relative contribution of geographic distance and environmental dissimilarity to the spatial genetic pattern. Results A relatively low level of genetic diversity within populations was found. No spatial genetic structure was suggested by the analyses of molecular variance, Bayesian clustering analysis and Mantel tests. Partial Mantel tests and multiple matrix regression analysis showed a significant influence of the environment on the genetic divergence of the species. Both climatic and water quality variables contribute to the habitat heterogeneity of R. subrigidus populations. Conclusions Our results suggest that historical processes involving long-distance dispersal and local adaptation may account for the genetic patterns of R. subrigidus and current environmental factors play an important role in the genetic differentiation and local adaptation of aquatic plants in alpine landscapes.

Assessment of genetic variability amongst cultivated populations of Khasi mandarin (Citrus reticulata Blanco) detected by ISSR

2021 ◽  
pp. 1-11
Author(s):  
Karishma Kashyap ◽  
Rasika M. Bhagwat ◽  
Sofia Banu
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Inter Simple Sequence Repeat ◽  
Northeast India ◽  
Issr Markers ◽  
Citrus Reticulata ◽  
Brahmaputra Valley ◽  
Indian Food ◽  
Cultivated Populations ◽  
High Level

Abstract Khasi mandarin (Citrus reticulata Blanco) is a commercial mandarin variety grown in northeast India and one of the 175 Indian food items included in the global first food atlas. The cultivated plantations of Khasi mandarin grown prominently in the lower Brahmaputra valley of Assam, northeast India, have been genetically eroded. The lack in the efforts for conservation of genetic variability in this mandarin variety prompted diversity analysis of Khasi mandarin germplasm across the region. Thus, the study aimed to investigate genetic diversity and partitioning of the genetic variations within and among 92 populations of Khasi mandarin collected from 10 cultivated sites in Kamrup and Kamrup (M) districts of Assam, India, using Inter-Simple Sequence Repeat (ISSR) markers. The amplification of genomic DNA with 17 ISSR primers yielded 216 scorable DNA amplicons of which 177 (81.94%) were polymorphic. The average polymorphism information content was 0.39 per primer. The total genetic diversity (HT = 0.28 ± 0.03) was close to the diversity within the population (HS = 0.20 ± 0.01). A high mean coefficient of gene differentiation (GST = 0.29) reflected a high level of gene flow (Nm = 1.22), indicating high genetic differentiation among the populations. Analysis of Molecular Variance (AMOVA) showed 78% of intra-population differentiation, 21% among the population and 1% among the districts. The obtained results indicate the existence of a high level of genetic diversity in the cultivated Khasi mandarin populations, indicating the need for preservation of each existing population to revive the dying out orchards in northeast India.

scholarly journals Target Localization Based on Bistatic T/R Pair Selection in GNSS-Based Multistatic Radar System

2021 ◽  
Vol 13 (4) ◽  
pp. 707
Author(s):  
Yu’e Shao ◽  
Hui Ma ◽  
Shenghua Zhou ◽  
Xue Wang ◽  
Michail Antoniou ◽  
...  
Keyword(s):  
Optimization Methods ◽  
Optimization Method ◽  
Satellite System ◽  
Radar System ◽  
Target Localization ◽  
Computational Load ◽  
Matrix Fusion ◽  
Global Navigation Satellite ◽  
Multistatic Radar ◽  
Combined Algorithm

To cope with the increasingly complex electromagnetic environment, multistatic radar systems, especially the passive multistatic radar, are becoming a trend of future radar development due to their advantages in anti-electronic jam, anti-destruction properties, and no electromagnetic pollution. However, one problem with this multi-source network is that it brings a huge amount of information and leads to considerable computational load. Aiming at the problem, this paper introduces the idea of selecting external illuminators in the multistatic passive radar system. Its essence is to optimize the configuration of multistatic T/R pairs. Based on this, this paper respectively proposes two multi-source optimization algorithms from the perspective of resolution unit and resolution capability, the Covariance Matrix Fusion Method and Convex Hull Optimization Method, and then uses a Global Navigation Satellite System (GNSS) as an external illuminator to verify the algorithms. The experimental results show that the two optimization methods significantly improve the accuracy of multistatic positioning, and obtain a more reasonable use of system resources. To evaluate the algorithm performance under large number of transmitting/receiving stations, further simulation was conducted, in which a combination of the two algorithms were applied and the combined algorithm has shown its effectiveness in minimize the computational load and retain the target localization precision at the same time.

scholarly journals Exploration of Semantic Geo-Object Recognition Based on the Scale Parameter Optimization Method for Remote Sensing Images

2021 ◽  
Vol 10 (6) ◽  
pp. 420
Author(s):  
Jun Wang ◽  
Lili Jiang ◽  
Qingwen Qi ◽  
Yongji Wang
Keyword(s):  
Parameter Optimization ◽  
Scale Parameter ◽  
Human Perception ◽  
Optimization Methods ◽  
Optimization Method ◽  
Initiation Point ◽  
Scale Parameters ◽  
Object Based ◽  
Geographic Object ◽  
Multiresolution Segmentation

Image segmentation is of significance because it can provide objects that are the minimum analysis units for geographic object-based image analysis (GEOBIA). Most segmentation methods usually set parameters to identify geo-objects, and different parameter settings lead to different segmentation results; thus, parameter optimization is critical to obtain satisfactory segmentation results. Currently, many parameter optimization methods have been developed and successfully applied to the identification of single geo-objects. However, few studies have focused on the recognition of the union of different types of geo-objects (semantic geo-objects), such as a park. The recognition of semantic geo-objects is likely more crucial than that of single geo-objects because the former type of recognition is more correlated with the human perception. This paper proposes an approach to recognize semantic geo-objects. The key concept is that a single geo-object is the smallest component unit of a semantic geo-object, and semantic geo-objects are recognized by iteratively merging single geo-objects. Thus, the optimal scale of the semantic geo-objects is determined by iteratively recognizing the optimal scales of single geo-objects and using them as the initiation point of the reset scale parameter optimization interval. In this paper, we adopt the multiresolution segmentation (MRS) method to segment Gaofen-1 images and tested three scale parameter optimization methods to validate the proposed approach. The results show that the proposed approach can determine the scale parameters, which can produce semantic geo-objects.

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