Assessment of molecular diversity in landraces of bread wheat (Triticum aestivum L.) held in an ex situ collection with Diversity Arrays Technology (DArT™)

2007 ◽  
Vol 58 (12) ◽  
pp. 1174 ◽  
Author(s):  
B. J. Stodart ◽  
M. C. Mackay ◽  
H. Raman
Keyword(s):  
Genetic Diversity ◽  
Molecular Diversity ◽  
Polymorphic Information Content ◽  
Ex Situ ◽  
Dart Markers ◽  
Strong Positive Correlation ◽  
High Genetic Diversity ◽  
Diversity Arrays Technology ◽  
Wheat Landraces ◽  
Landrace Accessions

Diversity Arrays Technology (DArT™) was evaluated as a tool for determining molecular diversity of wheat landraces held within the Australian Winter Cereals Collection (AWCC). Initially, a set of 44 wheat landraces was evaluated with 256 DArT markers. The dataset was compared with the results obtained using 16 amplified fragment length polymorphism (AFLP) primer combinations and 63 simple sequence repeat (SSR) markers, mapped on the 21 chromosomes, from a previous study. The DArT markers exhibited a strong positive correlation with AFLP and SSR, with each marker type distinguishing similar relationships among the 44 landrace accessions. The DArT markers exhibited a higher polymorphic information content than AFLP, and were comparable with that obtained with SSR. Three hundred and fifty-five DArT markers were then used to evaluate genetic diversity among 705 wheat landrace accessions from within the AWCC, chosen to represent 5 world regions. DArT analysis was capable of distinguishing accessions from different geographic regions, and suggested that accessions originating from Nepal represent a unique gene pool within the collection. A statistical resampling of DArT loci indicated that 10–20 loci were enough to distinguish the maximum molecular diversity present within the collection. This research demonstrates the efficacy of the DArT platform as a tool for efficient examination of wheat diversity. As an ex situ germplasm repository, the AWCC contains wheat accessions of high genetic diversity, from genetically differentiated collection sites, even though diversity was under-represented in some countries represented in the repository.

scholarly journals Molecular Assessment of Genetic Diversity among Egyptian Landraces of Wheat (Triticum aestivum L.) Using Microsatellite Markers

2020 ◽  
pp. 46-58 ◽  
Author(s):  
Ahmed Medhat Mohamed Al-Naggar ◽  
Mohamed Abd El-Maboud Abd El-Shafi ◽  
Mohamed Helmy El-Shal ◽  
Ali Hassan Anany
Keyword(s):  
Genetic Diversity ◽  
Triticum Aestivum ◽  
Microsatellite Markers ◽  
Ssr Markers ◽  
Triticum Aestivum L ◽  
Genetic Progress ◽  
High Genetic Diversity ◽  
Breeding Programs ◽  
High Polymorphism Information Content ◽  
Wheat Landraces

To increase the genetic progress in wheat (Triticum aestivum L.) yield, breeders search for germplasm of high genetic diversity, one of them is the landraces. The present study aimed at evaluating genetic diversity of 20 Egyptian wheat landraces and two cultivars using microsatellite markers (SSRs). Ten SSR markers amplified a total of 27 alleles in the set of 22 wheat accessions, of which 23 alleles (85.2%) were polymorphic. The majority of the markers showed high polymorphism information content (PIC) values (0.67-0.94), indicating the diverse nature of the wheat accessions and/or highly informative SSR markers used in this study. The genotyping data of the SSR markers were used to assess genetic variation in the wheat accessions by dendrogram. The highest genetic distance was found between G21 (Sakha 64; an Egyptian cultivar) and the landrace accession No. 9120 (G11). These two genotypes could be used as parents in a hybridization program followed by selection in the segregating generations, to identify some transgressive segregates of higher grain yield than both parents. The clustering assigned the wheat genotypes into four groups based on SSR markers. The results showed that the studied SSR markers, provided sufficient polymorphism and reproducible fingerprinting profiles for evaluating genetic diversity of wheat landraces. The analyzed wheat landraces showed a good level of genetic diversity at the molecular level. Molecular variation evaluated in this study of wheat landraces can be useful in traditional and molecular breeding programs.

scholarly journals Genetic Diversity and Population Structure of Cowpea [Vigna unguiculata (L.) Walp.] Germplasm Collected from Togo Based on DArT Markers

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1451
Author(s):  
Kodjo M. Gbedevi ◽  
Ousmane Boukar ◽  
Haruki Ishikawa ◽  
Ayodeji Abe ◽  
Patrick O. Ongom ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Improvement ◽  
Agricultural Research ◽  
Polymorphic Information Content ◽  
Germplasm Collection ◽  
Mean Value ◽  
Economic Life ◽  
Dart Markers ◽  
Crop Genetic Diversity

Crop genetic diversity is a sine qua non for continuous progress in the development of improved varieties, hence the need for germplasm collection, conservation and characterization. Over the years, cowpea has contributed immensely to the nutrition and economic life of the people in Togo. However, the bulk of varieties grown by farmers are landraces due to the absence of any serious genetic improvement activity on cowpea in the country. In this study, the genetic diversity and population structure of 255 cowpea accessions collected from five administrative regions and the agricultural research institute of Togo were assessed using 4600 informative diversity array technology (DArT) markers. Among the regions, the polymorphic information content (PIC) ranged from 0.19 to 0.27 with a mean value of 0.25. The expected heterozygosity (He) varied from 0.22 to 0.34 with a mean value of 0.31, while the observed heterozygosity (Ho) varied from 0.03 to 0.07 with an average of 0.05. The average inbreeding coefficient (FIS) varied from 0.78 to 0.89 with a mean value of 0.83, suggesting that most of the accessions are inbred. Cluster analysis and population structure identified four groups with each comprising accessions from the six different sources. Weak to moderate differentiation was observed among the populations with a genetic differentiation index varying from 0.014 to 0.117. Variation was highest (78%) among accessions within populations and lowest between populations (7%). These results revealed a moderate level of diversity among the Togo cowpea germplasm. The findings of this study constitute a foundation for genetic improvement of cowpea in Togo.

scholarly journals Prevalence of bovine astroviruses and their genotypes in sampled Chinese calves with and without diarrhoea

2021 ◽  
Vol 102 (8) ◽  
Author(s):  
Jie Zhu ◽  
Mingpu Qi ◽  
Chuanwen Jiang ◽  
Yongchong Peng ◽  
Qingjie Peng ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Binary Logistic Regression ◽  
Binary Logistic Regression Analysis ◽  
Strong Positive Correlation ◽  
High Genetic Diversity ◽  
Bovine Rotavirus ◽  
Calf Diarrhoea ◽  
Faecal Samples ◽  
Polymerase Chain ◽  
Next Generation Sequencing Ngs

Bovine astrovirus (BoAstV) belongs to genus Mamastravirus (MAstV). It can be detected in the faeces of both diarrhoeal and healthy calves. However, its prevalence, genetic diversity, and association with cattle diarrhoea are poorly understood. In this study, faecal samples of 87 diarrhoeal and 77 asymptomatic calves from 20 farms in 12 provinces were collected, and BoAstV was detected with reverse transcription-polymerase chain reaction (RT-PCR). The overall prevalence rate of this virus in diarrhoeal and asymptomatic calves was 55.17 % (95 % CI: 44.13, 65.85 %) and 36.36 % (95 % CI: 25.70, 48.12 %), respectively, indicating a correlation between BoAstV infection and calf diarrhoea (OR=2.15, P=0.024). BoAstV existed mainly in the form of co-infection (85.53 %) with one to five of nine viruses, and there was a strong positive correlation between BoAstV co-infection and calf diarrhoea (OR=2.83, P=0.004). Binary logistic regression analysis confirmed this correlation between BoAstV co-infection and calf diarrhoea (OR=2.41, P=0.038). The co-infection of BoAstV and bovine rotavirus (BRV) with or without other viruses accounted for 70.77 % of all the co-infection cases. The diarrhoea risk for the calves co-infected with BoAstV and BRV was 8.14-fold higher than that for the calves co-infected with BoAstV and other viruses (OR=8.14, P=0.001). Further, the co-infection of BoAstV/BRV/bovine kobuvirus (BKoV) might increase the risk of calf diarrhoea by 14.82-fold, compared with that of BoAstV and other viruses (OR=14.82, P <0.001). Then, nearly complete genomic sequences of nine BoAstV strains were assembled by using next-generation sequencing (NGS) method. Sequence alignment against known astrovirus (AstV) strains at the levels of both amino acids and nucleotides showed a high genetic diversity. Four genotypes were identified, including two known genotypes MAstV-28 (n=3) and MAstV-33 (n=2) and two novel genotypes designated tentatively as MAstV-34 (n=1) and MAstV-35 (n=3). In addition, seven out of nine BoAstV strains showed possible inter-genotype recombination and cross-species recombination. Therefore, our results increase the knowledge about the prevalence and the genetic evolution of BoAstV and provide evidence for the association between BoAstV infection and calf diarrhoea.

scholarly journals Morpho-Molecular Diversity Analysis of Local Rice (Oryza sativa L.) Genotypes Using Microsatellite Markers

2020 ◽  
pp. 92-104
Author(s):  
S. K. Singh ◽  
Charupriya Singh ◽  
Mounika Korada ◽  
Sonali Habde ◽  
D. K. Singh ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Diversity ◽  
Agricultural Research ◽  
Polymorphic Information Content ◽  
Block Design ◽  
Genetic Enhancement ◽  
Diversity Analysis ◽  
Cluster Distance ◽  
Breeding Programmes ◽  
Rice Genotypes

Aim: The knowledge of genetic diversity and relationship among the genotypes play a significant role for genetic enhancement in breeding programmes to increase production, improve quality, biotic and abiotic stresses, and also for the selection of superior parental lines in rice. The present field experiment was conducted to study the diversity present in 29 local genotypes of rice using both morphological and molecular ways. Methodology: The experiment was conducted at Agricultural Research Farm, Banaras Hindu University, during Kharif-2017 in an augmented block design with 29 rice genotypes including 3 checks. Mahalanobis’ D2 analysis was carried out to assess the morphological diversity present among the genotypes and molecular analysis was done with 21 polymorphic SSR markers using the NTSYSpc software. Results: Mahalanobis’ D2 grouped the 29 genotypes into 6 clusters based on the inter-se genetic distance. The highest intra-cluster distance was recorded in the Cluster I (32.73), which comprised of 7 genotypes. The highest inter-cluster distance (65.86) was observed between Clusters IV and V. Molecular diversity analysis grouped the 29 rice genotypes into 2 main clusters i.e. cluster I and cluster II with dissimilarity coefficient of 0.34, which were further divided into sub-clusters. Polymorphic Information Content (PIC) value is an evidence of diversity and frequency among the varieties. The level of polymorphism varied from 0.164 to 0.694, with an average 0.521. The highest PIC value was observed for locus RM 5 (0.694) followed by RM 510 (0.692). All the 21 primers showed polymorphism and the number of alleles ranged from 2 to 4 with an average of 3.04.  Conclusion: This study established the presence of considerable amount of genetic diversity among the genotypes studied, the most diverse genotypes being Anupam gold and HUR-1309 followed by Kalanamak-2 and HUR-1304. Breeders may attempt hybridization among the above genotypes which showed maximum diversity, for creating more variability in rice and can be used for planning further breeding programmes.

scholarly journals Morphological Characterization and Genetic Diversity Analysis of a Tunisian Durum Wheat (Triticum Turgidum Var. Durum) Collection

2020 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Amina Bahri ◽  
Lamia Aouini ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Durum Wheat ◽  
Gene Diversity ◽  
Polymorphic Information Content ◽  
Morphological Characterization ◽  
Genetic Variations ◽  
Mantel Test ◽  
Ex Situ ◽  
The South ◽  
Population Structure Analysis

Abstract Background: Tunisia is a center of genetic diversity of durum wheat and has a large number of abandoned old local landraces. An accurate investigation and characterization of the morphological and genetic features of these landraces would allow their rehabilitation and use for practical and beneficial purposes. In this context, a collection of 304 local accessions of durum wheat, collected from five regions and three climatic zones of central and southern Tunisia, was studied. Results: Morphological characterization was carried out using 12 spike-related traits and rendered a mean Shannon-Weaver Index (H') of 0.80 indicating the presence of a high level of polymorphism among accessions. Based on these traits 11 local landraces, namely Mahmoudi, Azizi, Jneh Khotifa, Mekki, Biskri, Taganrog, Biada, Badri, Richi, Roussia and Souri were identified. Spike length (H’=0.98) and shape (H’=0.86) with grains size (H’=0.94), form (H’=0.87) and color (H’=0.86) were the most polymorphic morphological traits. The genetic diversity was assessed using 10 SSR markers, with a polymorphic information content (PIC) of 0.69. Levels of genetic diversity were generally high, with a Shannon's Information Index (I) of 0.62 and a gene diversity (He) of 0.35. In addition, population structure analysis distinguished 11 genetic groups resulted from STRUCTURE and Mantel test showed a significant correlation between genetic and morphological distances. Analysis of molecular variance (AMOVA) showed high genetic variations within regions (81%) and wheat subpopulations (41%) showing a considerable amount of admixture between landraces realized by farmers; as well as a moderate (19%) and high (59%) genetic variations among regions and wheat subpopulations, indicating practices of selection pressure conducted by farmers. The Mahmoudi landrace showed spike densities significantly different between the center to the south of Tunisia; notably loose spikes with open glumes in the south and compact ones in the center, which may represent an adaptation form for tolerance to high temperature. Conclusion: Overall, this study highlights the genetic richness of local resources for better in situ or ex situ conservation and for their subsequent use in plant breeding programs.

scholarly journals High Genetic Diversity and Low Differentiation in Michelia shiluensis, an Endangered Magnolia Species in South China

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 469 ◽  
Author(s):  
Yanwen Deng ◽  
Tingting Liu ◽  
Yuqing Xie ◽  
Yaqing Wei ◽  
Zicai Xie ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Human Disturbance ◽  
Haplotype Diversity ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Conservation Strategies ◽  
High Genetic Diversity ◽  
Cpdna Markers

Research Highlights: This study is the first to examine the genetic diversity of Michelia shiluensis (Magnoliaceae). High genetic diversity and low differentiation were detected in this species. Based on these results, we discuss feasible protection measures to provide a basis for the conservation and utilization of M. shiluensis. Background and Objectives: Michelia shiluensis is distributed in Hainan and Guangdong province, China. Due to human disturbance, the population has decreased sharply, and there is thus an urgent need to evaluate genetic variation within this species in order to identify an optimal conservation strategy. Materials and Methods: In this study, we used eight nuclear single sequence repeat (nSSR) markers and two chloroplast DNA (cpDNA) markers to assess the genetic diversity, population structure, and dynamics of 78 samples collected from six populations. Results: The results showed that the average observed heterozygosity (Ho), expected heterozygosity (He), and percentage of polymorphic loci (PPL) from nSSR markers in each population of M. shiluensis were 0.686, 0.718, and 97.92%, respectively. For cpDNA markers, the overall haplotype diversity (Hd) was 0.674, and the nucleotide diversity was 0.220. Analysis of markers showed that the genetic variation between populations was much lower based on nSSR than on cpDNA (10.18% and 77.56%, respectively, based on an analysis of molecular variance (AMOVA)). Analysis of the population structure based on the two markers shows that one of the populations (DL) is very different from the other five. Conclusions: High genetic diversity and low population differentiation of M. shiluensis might be the result of rich ancestral genetic variation. The current decline in population may therefore be due to human disturbance rather than to inbreeding or genetic drift. Management and conservation strategies should focus on maintaining the genetic diversity in situ, and on the cultivation of seedlings ex-situ for transplanting back to their original habitat.

Exploring the Genetic Diversity of Some Squash (Cucurbita Maxima L.) Germplasm Using Morphological and Molecular Markers in Erzincan

2021 ◽  
Author(s):  
HALIL IBRAHIM OZTURK ◽  
Veysel Dönderalp ◽  
Hüseyin Bulut ◽  
Recep Korkut ◽  
Arash HOSSEINPOUR ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Ssr Markers ◽  
Molecular Level ◽  
Polymorphic Information Content ◽  
Plant Genetic Resources ◽  
Molecular Characteristics ◽  
Cucurbita Maxima ◽  
High Genetic Diversity ◽  
The Mean

Abstract Background Plant genetic resources constitute the most valuable assets of countries. It is of great importance to determine the genetic variation among these resources and to use the data in breeding studies. Cucurbita maxima species in the cucurbitaceae family have high genetic diversity, but its genetic diversity at the molecular level is inadequately characterized. Methods and Results To determine the genetic diversity among genotypes of Cucurbita maxima species of squash, which is widely grown in Erzincan, 14 different squash genotypes collected were examined based on the morphological parameters and molecular characteristics. SSR (Simple sequence repeat) markers were used to determine genetic diversity at the molecular level. The analysis of morphological characterization within genotypes showed a wide variability in morphological traits of plant, flower, fruit, and leaf. Seven SSR markers yielded a total of 23 polymorphic bands, the number of alleles per marker ranged from 2 to 5, and the mean number of alleles was 3.286. Polymorphic information content (PIC) ranged from 0.00 (GMT-M61) to 0.202 (GMT-P25), and the mean PIC value per marker was 0.130. Cluster analysis using Nei's genetic distance determined that 14 genotypes were divided into 3 major groups. Conclusions The SSR markers used were effective in distinguish among similar winter squash or pumpkin and therefore can be beneficial for consideration of Cucurbita maxima species diversity, screening of genetic resources and their selection.

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