scholarly journals Comparing the efficiency of sampling strategies to establish a representative in the phenotypic-based genetic diversity core collection of orchardgrass (Dactylis glomerata L.)

2013 ◽  
Vol 49 (No. 1) ◽  
pp. 36-47 ◽  
Author(s):  
M. Studnicki ◽  
W. Mądry ◽  
J. Schmidt
Keyword(s):  
Genetic Diversity ◽  
Core Collection ◽  
Dactylis Glomerata ◽  
Sampling Strategy ◽  
Sampling Strategies ◽  
Core Collections ◽  
The Core ◽  
Entire Collection ◽  
The Mean ◽  
Dactylis Glomerata L

Establishing a core collection that represents the genetic diversity of the entire collection with a minimum loss of its original diversity and minimal redundancies is an important problem for gene bank curators and crop breeders. In this paper, we assess the representativeness of the original genetic diversity in core collections consisting of one-tenth of the entire collection obtained according to 23 sampling strategies. The study was performed using the Polish orchardgrass Dactylis glomerata L. germplasm collection as a model. The representativeness of the core collections was validated by the difference of means (MD%) and difference of mean squared Euclidean distance (d‒D%) for the studied traits in the core subsets and the entire collection. In this way, we compared the efficiency of a simple random and 22 (20 cluster-based and 2 direct cluster-based) stratified sampling strategies. Each cluster-based stratified sampling strategy is a combination of 2 clusterings, 5 allocations and 2 methods of sampling in a group. We used the accession genotypic predicted values for 8 quantitative traits tested in field trials. A sampling strategy is considered more effective for establishing core collections if the means of the traits in a core are maintained at the same level as the means in the entire collection (i.e., the mean of MD% in the simulated samples is close to zero) and, simultaneously, when the overall variation in a core collection is greater than in the entire collection (i.e., the mean of d‒D% in the simulated samples is greater than that obtained for the simple random sampling strategy). Both cluster analyses (unweighted pair group method with arithmetic mean UPGMA and Ward) were similarly useful in constructing those sampling strategies capable of establishing representative core collections. Among the allocation methods that are relatively most useful for constructing efficient samplings were proportional and D2 (including variation). Within the Ward clusters, the random sampling was better than the cluster-based sampling, but not within the UPGMA clusters.

Development of core subset for the collection of Chinese cultivated eggplants using morphological-based passport data

2008 ◽  
Vol 6 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Mao Weihai ◽  
Yi Jinxin ◽  
Darasinh Sihachakr
Keyword(s):  
Core Collection ◽  
Solanum Melongena ◽  
Sampling Strategy ◽  
Sampling Strategies ◽  
Numerical Classification ◽  
Clustering Methods ◽  
Single Linkage ◽  
The Core ◽  
Pair Group ◽  
Passport Data

A total of 1968 accessions of cultivated eggplants, belonging to Solanum melongena and Solanum aethiopicum and procured from the IVC/JAAS (Nanjing) and IVC/ZAAS (Hangzhou), China, were examined for 23 morphological traits, such as characteristics of plant, stems, leaves, flowers, fruits and original geographic information. A comprehensive numerical classification methodology, including two types of genetic distance, viz. Mahalanobis (Ma) distance and Euclidean (Eu) distance; four clustering methods, viz. unweighted pair group average (UPGA), Ward's (W), complete linkage (CL) and single linkage (SL) methods; three sampling strategies, viz. random (R), preferred (P) and deviation (D); and four sampling sizes (10, 15, 20 and 30% of initial collection), was used to divide all accessions into main groups and subgroups for the establishment of candidate collections. The evaluation of these candidate collections showed that a combination of Eu distance, UPGA clustering method, and R or P sampling strategy with sampling size at 15–20% was suitable for establishing the core collection, providing an adequate and representative genetic diversity of the initial collection of the cultivated eggplants.

scholarly journals Identification of a Diverse Core Set Panel of Rice From the East Coast Region of India Using SNP Markers

2021 ◽  
Vol 12 ◽  
Author(s):  
Debjani Roy Choudhury ◽  
Ramesh Kumar ◽  
Vimala Devi S ◽  
Kuldeep Singh ◽  
N. K. Singh ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Core Collection ◽  
Tamil Nadu ◽  
East Coast ◽  
Snp Markers ◽  
The Core ◽  
Core Set ◽  
Population Structure Analysis ◽  
The Mean

In India, rice (Oryza sativa L.) is cultivated under a variety of climatic conditions. Due to the fragility of the coastal ecosystem, rice farming in these areas has lagged behind. Salinity coupled with floods has added to this trend. Hence, to prevent genetic erosion, conserving and characterizing the coastal rice, is the need of the hour. This work accessed the genetic variation and population structure among 2,242 rice accessions originating from India’s east coast comprising Andhra Pradesh, Orissa, and Tamil Nadu, using 36 SNP markers, and have generated a core set (247 accessions) as well as a mini-core set (30 accessions) of rice germplasm. All the 36 SNP loci were biallelic and 72 alleles found with average two alleles per locus. The genetic relatedness of the total collection was inferred using the un-rooted neighbor-joining tree, which grouped all the genotypes (2,242) into three major clusters. Two groups were obtained with a core set and three groups obtained with a mini core set. The mean PIC value of total collection was 0.24, and those of the core collection and mini core collection were 0.27 and 0.32, respectively. The mean heterozygosity and gene diversity of the overall collection were 0.07 and 0.29, respectively, and the core set and mini core set revealed 0.12 and 0.34, 0.20 and 0.40 values, respectively, representing 99% of distinctiveness in the core and mini core sets. Population structure analysis showed maximum population at K = 4 for total collection and core collection. Accessions were distributed according to their population structure confirmed by PCoA and AMOVA analysis. The identified small and diverse core set panel will be useful in allele mining for biotic and abiotic traits and managing the genetic diversity of the coastal rice collection. Validation of the 36-plex SNP assay was done by comparing the genetic diversity parameters across two different rice core collections, i.e., east coast and northeast rice collection. The same set of SNP markers was found very effective in deciphering diversity at different genetic parameters in both the collections; hence, these marker sets can be utilized for core development and diversity analysis studies.

scholarly journals Genetic Diversity and Structure of Core Collection of Huangqi (Astragalus) Developed by Genomic Simple Sequence Repeat Markers

2022 ◽  
Author(s):  
Fanshu Gong ◽  
Yaping Geng ◽  
Pengfei Zhang ◽  
Feng Zhang ◽  
Xinfeng Fan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Simulated Annealing ◽  
Core Collection ◽  
Phylogenetic Trees ◽  
Simulated Annealing Algorithm ◽  
Therapeutic Effects ◽  
Core Collections ◽  
The Core ◽  
Genetic Diversity And Structure ◽  
Annealing Algorithm

Abstract Huangqi (Astragalus) is a versatile herb that possesses several therapeutic effects against a variety of diseases, especially lung diseases. The aim of this study was to establish a core collection of Astragalus germplasm resources based on molecular 10 SSR markers. Based on 380 samples of Astragalus collected from different areas, five different methods were utilized to construct the core collection of Astragalus, including PowerCore-based M strategy, CoreFinder-based M strategy, Core Hunter-based stepwise sampling, PowerMarker-based simulated annealing algorithm based on allele maximization, and PowerMarker-based simulated annealing algorithm based on maximizing genetic diversity. Of the constructed Astragalus core collections, the CoreFinder-based M strategy was found to be the most suitable approach as it reserved all the alleles and most of the genetic diversity parameters were higher than those of the initial collection. Additional analyses demonstrated that the genetic diversity of the core collection matched the properties of the initial collection. Further, the phylogenetic trees indicated that the population structure of the core collection was similar to that of the initial collection. In addition, our results showed that the optimal grouping value of K was 2. The construction of a core collection is beneficial for the understanding, management, and utilization of Astragalus. Moreover, this study will act as a valuable reference for constructing core collections for other plants or fungi.

Genetic diversity and establishment of a core collection of oil palm (Elaeis guineensisJacq.) based on molecular data

2014 ◽  
Vol 13 (3) ◽  
pp. 256-265 ◽  
Author(s):  
Diana Arias ◽  
Maria González ◽  
Hernán Romero
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Genetic Resources ◽  
Oil Palm ◽  
Core Collection ◽  
Molecular Data ◽  
Core Collections ◽  
Mini Core Collection ◽  
Entire Collection ◽  
Breeding Programmes

Understanding of genetic diversity and its distribution is essential for promoting the use of genetic resources. The development of core collections using molecular tools has been proposed as a strategy for increasing the economical use and conservation of genetic resources. In this study, we investigated the genetic variation among different geographical origins and potential entries that constituted a core collection of oil palm, using 29 microsatellite markers and by evaluating 788 oil palm accessions. Our results revealed important genetic diversity (HT= 0.759) between oil palm accessions from Angola and Cameroon, which exhibited a low coefficient of genetic differentiation between populations (GST= 0.022). However, the inclusion of oil palm accessions from Indonesia in the analysis resulted in a high coefficient of genetic differentiation between populations (GST= 0.251). We found that the combination of stratified sampling based on a sorting method and a heuristic algorithm was the most effective method for the development of an oil palm core collection set. Using this method, two core collections were identified. The first core collection, comprising 289 entries, contained 271 retained alleles in a sample representing 37% of the entire collection. The second one is a mini core collection, comprising 91 entries, that contained 271 retained alleles with a totalHevalue of 0.72 in a sample representing 11% of the entire collection. The information reported in this study will be of great interest to oil palm researchers because new strategies for breeding programmes can be developed based on these advances.

scholarly journals Peach palm core collection in Brazilian Amazonia

2015 ◽  
Vol 15 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Michelly de Cristo-Araújo ◽  
Doriane Picanço Rodrigues ◽  
Spartaco Astolfi-Filho ◽  
Charles R. Clement
Keyword(s):  
Genetic Diversity ◽  
Core Collection ◽  
Wild Populations ◽  
Germplasm Bank ◽  
Molecular Polymorphism ◽  
Molecular Variance ◽  
Peach Palm ◽  
The Core ◽  
Entire Collection

The Peach palm Active Germplasm Bank has abundant genetic diversity in its holdings. Because it is a live collection, maintenance, characterization and evaluation are expensive, restricting its use. One way to promote more efficient use is to create a Core Collection, a set of accessions with at least 70% of the genetic diversity of the full collection with minimal repetition. The available geographic, molecular marker (RAPD) and morphometric information was systematized and the populations were stratified into wild and domesticated. The Core Collection consists of 10% of the entire collection: 31 accessions of landraces, 5 accessions of non-designated populations and 4 accessions of wild populations. The Core has 92% of the molecular polymorphism and 95% of the heterozygosity of the full collection, with minimal divergence between them by molecular variance. The Core is already receiving priority maintenance, which will contribute to long term conservation.

scholarly journals Constructing a Core Collection of the Medicinal Plant Angelica biserrata Using Genetic and Metabolic Data

2020 ◽  
Vol 11 ◽  
Author(s):  
Man Liu ◽  
Xin Hu ◽  
Xu Wang ◽  
Jingjing Zhang ◽  
Xubing Peng ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Medicinal Plant ◽  
Core Collection ◽  
Polymorphic Information Content ◽  
Sampling Strategy ◽  
Market Demand ◽  
Conservation Assessment ◽  
Information Index ◽  
Ssr Loci ◽  
Metabolic Data

Angelica biserrata is an important medicinal plant in Chinese traditional medicine. Its roots, which are known as Duhuo in Chinese, are broadly applied to treat inflammation, arthritis, and headache. With increasing market demand, the wild resources of A. biserrata have been overexploited, and conservation, assessment of genetic resources and breeding for this species is needed. Here, we sequenced the transcriptome of A. biserrata and developed simple sequence repeat (SSR) markers from it to construct a core collection based on 208 samples collected from Changyang-related regions. A total of 132 alleles were obtained for 17 SSR loci used with the polymorphic information content (PIC) ranging from 0.44 to 0.83. Abundant genetic diversity was inferred by Shannon’s information index (1.51), observed (0.57) and expected heterozygosity (0.72). The clustering analysis resulted into two sample groups and analysis of molecular variance (AMOVA) showed only 6% genetic variation existed among populations. A further metabolic analysis of these samples revealed the main coumarin contents, such as osthole and columbianadin. According to the genetic and metabolic data, we adopted the least distance stepwise sampling strategy to construct seven preliminary core collections, of which the 20CC collection, which possessed 42 A. biserrata individuals accounting for 90.20% of the genetic diversity of the original germplasm, represented the best core collection. This study will contribute to the conservation and management of A. biserrata wild germplasm resources and provide a material basis for future selection and breeding of this medicinal plant.

scholarly journals Selection of Core Collection from Jesso-Balam Rice (Oryza sativa L.) Accessions Using Quantitative, Qualitative and Molecular Characters-A Review

2017 ◽  
Vol 15 (1) ◽  
pp. 170-181
Author(s):  
MS Ahmed ◽  
Khandakar Md. Iftekharuddaula
Keyword(s):  
Oryza Sativa ◽  
Core Collection ◽  
Oryza Sativa L ◽  
Hierarchical Cluster ◽  
Genetic Distances ◽  
Sampling Strategies ◽  
The Core ◽  
Rice Genotypes ◽  
Molecular Characters ◽  
Selection Of

Genetic improvement of rice (Oryza sativa L.) for yield is important for increasing demand of the growing population and the changing climate of the world. Recent studies showed that backcrossing twice using modern varieties as receptor and mini core collection as doner, most of the undesirable traits could be improved remarkably and in other words its maximum allele diversity could be brought back into rice fields. Core collection is defined as a subset chosen to represent the most genetic diversity of an initial collection with a minimum of redundancies. The objective of the present study was to review the selection of core collection of Jesso-Balam group of rice genotypes through quantitative, qualitative and molecular characters. Earlier, the same germplasms were characterized for agro-morphological, physico-chemical and molecular characters and grouped into different clusters by different methods at Bangladesh Rice Research Institute during 2009-12. Finally, the core collection was selected by reviewing the above characterized data and using the hierarchical cluster analysis. Moreover, the selection processes of core collection were improved by applying composite evaluation methods; such as agro-morphological traits, biochemical characters and so on, through sampling strategies based on genotypic values, predicted genotypic value, comparing different genetic distances, cluster methods and sampling strategies methods, molecular characterization or SSR marker base data. As a result, the selected core germplasm of Jesso-Balam rice accessions were JBPL1, JBPL8, JBPL9, JBPL10, JBPL13, JBPL15, JBPL16, JBPL17, JBPL19, JBPL20, JBPL21, JBPL23, JBPL25 and JBPL26. In conclusion, the core collection  need to be considered as the ‘working collection’ of Jesso-Balam rice genotypes for their easy and safe conservation and effective utilization in Gene bank.The Agriculturists 2017; 15(1) 170-181

Evaluation of populations of Dactylis glomerata L. native to Mediterranean environments

2012 ◽  
Vol 63 (12) ◽  
pp. 1124 ◽  
Author(s):  
V. Copani ◽  
G. Testa ◽  
A. Lombardo ◽  
S. L. Cosentino
Keyword(s):  
Genetic Diversity ◽  
Biomass Yield ◽  
Agronomic Traits ◽  
Dactylis Glomerata ◽  
Leaf Length ◽  
Mediterranean Environment ◽  
Summer Dormancy ◽  
Low Levels ◽  
Dactylis Glomerata L ◽  
Different Levels

Several morphological and agronomic traits and the genetic diversity of nine Dactylis glomerata L. populations collected throughout Sicily (semi-arid Mediterranean environment) were evaluated for two successive years. Significant differences were recorded for morphological traits (plant height, leaf length, leaf width). In relation to the measurement of summer dormancy, the results suggest the expression of different levels of dormancy (completely dormant, semi-dormant, and non-dormant). For biomass yield, some Sicilian populations (SD63 and SD56) characterised by low levels of summer dormancy show production levels similar to the summer-active control varieties (Medly and Porto). However, SD46, with a much higher level of dormancy, gave biomass yield higher than the summer-dormant control variety (Kasbah). The genetic diversity evaluated by fAFLP analysis confirms the observed morphological and agronomic variability.

scholarly journals A Modified Roger’s Distance Algorithm for Mixed Quantitative–Qualitative Phenotypes to Establish a Core Collection for Taiwanese Vegetable Soybeans

2021 ◽  
Vol 11 ◽  
Author(s):  
Chung-Feng Kao ◽  
Shan-Syue He ◽  
Chang-Sheng Wang ◽  
Zheng-Yuan Lai ◽  
Da-Gin Lin ◽  
...  
Keyword(s):  
Core Collection ◽  
Dietary Habits ◽  
Phenotypic Traits ◽  
Variable Rate ◽  
Vegetable Soybean ◽  
Breeding Programs ◽  
The Core ◽  
Entire Collection ◽  
Redundant Accessions ◽  
High Diversity

Vegetable soybeans [Glycine max (L.) Merr.] have characteristics of larger seeds, less beany flavor, tender texture, and green-colored pods and seeds. Rich in nutrients, vegetable soybeans are conducive to preventing neurological disease. Due to the change of dietary habits and increasing health awareness, the demand for vegetable soybeans has increased. To conserve vegetable soybean germplasms in Taiwan, we built a core collection of vegetable soybeans, with minimum accessions, minimum redundancy, and maximum representation. Initially, a total of 213 vegetable soybean germplasms and 29 morphological traits were used to construct the core collection. After redundant accessions were removed, 200 accessions were retained as the entire collection, which was grouped into nine clusters. Here, we developed a modified Roger’s distance for mixed quantitative–qualitative phenotypes to select 30 accessions (denoted as the core collection) that had a maximum pairwise genetic distance. No significant differences were observed in all phenotypic traits (p-values > 0.05) between the entire and the core collections, except plant height. Compared to the entire collection, we found that most traits retained diversities, but seven traits were slightly lost (ranged from 2 to 9%) in the core collection. The core collection demonstrated a small percentage of significant mean difference (3.45%) and a large coincidence rate (97.70%), indicating representativeness of the entire collection. Furthermore, large values in variable rate (149.80%) and coverage (92.5%) were in line with high diversity retained in the core collection. The results suggested that phenotype-based core collection can retain diversity and genetic variability of vegetable soybeans, providing a basis for further research and breeding programs.

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