Evaluation of genetic diversity among bread wheat varieties and landraces of Pakistan by SSR markers

A set of 44 bread wheat landraces was used to determine the efficacy of 16 amplifed fragment length polymorphism (AFLP) primers and 63 wheat simple sequence repeat (SSR) markers in identifying polymorphisms between accessions. The SSR markers detected approximately 10 alleles per locus with a mean gene diversity (Hz) of 0.63, whereas AFLP primers identified approximately 147 fragments per primer with a mean gene diversity of 0.25. A set of 54 SSR markers and 11 AFLP primers was identified as highly polymorphic (polymorphic information content (PIC) ≥ 0.5 and 0.3 for SSR and AFLP, respectively), and suitable for molecular characterisation of germplasm. Principle coordinate analysis suggested that the AFLP and SSR loci could be used to discriminate among accessions collected from North Africa and southern Europe from those collected from the Middle East. Both marker types indicate that accessions from North Africa and southern Europe, the Middle East, and southern and eastern Asia are genetically diverse. The results indicate the usefulness of the molecular markers to assess genetic diversity present within germplasm collections.

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Discovery of miRNAs and Development of Heat-Responsive miRNA-SSR Markers for Characterization of Wheat Germplasm for Terminal Heat Tolerance Breeding

Frontiers in Genetics ◽

10.3389/fgene.2021.699420 ◽

2021 ◽

Vol 12 ◽

Author(s):

Pooja Sihag ◽

Vijeta Sagwal ◽

Anuj Kumar ◽

Priyanka Balyan ◽

Reyazul Rouf Mir ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Heat Stress ◽

Ssr Markers ◽

Heat Tolerance ◽

Wheat Varieties ◽

Wheat Genotypes ◽

Wheat Germplasm ◽

Heat Tolerant

A large proportion of the Asian population fulfills their energy requirements from wheat (Triticum aestivum L.). Wheat quality and yield are critically affected by the terminal heat stress across the globe. It affects approximately 40% of the wheat-cultivating regions of the world. Therefore, there is a critical need to develop improved terminal heat-tolerant wheat varieties. Marker-assisted breeding with genic simple sequence repeats (SSR) markers have been used for developing terminal heat-tolerant wheat varieties; however, only few studies involved the use of microRNA (miRNA)-based SSR markers (miRNA-SSRs) in wheat, which were found as key players in various abiotic stresses. In the present study, we identified 104 heat-stress-responsive miRNAs reported in various crops. Out of these, 70 miRNA-SSR markers have been validated on a set of 20 terminal heat-tolerant and heat-susceptible wheat genotypes. Among these, only 19 miRNA-SSR markers were found to be polymorphic, which were further used to study the genetic diversity and population structure. The polymorphic miRNA-SSRs amplified 61 SSR loci with an average of 2.9 alleles per locus. The polymorphic information content (PIC) value of polymorphic miRNA-SSRs ranged from 0.10 to 0.87 with a mean value of 0.48. The dendrogram constructed using unweighted neighbor-joining method and population structure analysis clustered these 20 wheat genotypes into 3 clusters. The target genes of these miRNAs are involved either directly or indirectly in providing tolerance to heat stress. Furthermore, two polymorphic markers miR159c and miR165b were declared as very promising diagnostic markers, since these markers showed specific alleles and discriminated terminal heat-tolerant genotypes from the susceptible genotypes. Thus, these identified miRNA-SSR markers will prove useful in the characterization of wheat germplasm through the study of genetic diversity and population structural analysis and in wheat molecular breeding programs aimed at terminal heat tolerance of wheat varieties.

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Genetic Diversity Among some Egyptian Bread Wheat Cultivars Based on Morphological Characters and SSR Markers

Assiut Journal of Agricultural Sciences ◽

10.21608/ajas.2020.69929 ◽

2020 ◽

Vol 49 (4) ◽

pp. 44-45

Keyword(s):

Genetic Diversity ◽

Bread Wheat ◽

Ssr Markers ◽

Morphological Characters ◽

Wheat Cultivars

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Genetic Diversity Analysis of Bread Wheat Varieties and Pre-release Lines Evaluated Under Timely Sown Irrigated Conditions

Indian Journal of Plant Genetic Resources ◽

10.5958/0976-1926.2021.00014.0 ◽

2021 ◽

Vol 34 (1) ◽

pp. 86-89

Author(s):

Vijay Kamal Meena ◽

RK Sharma ◽

Naresh Kumar ◽

Monu Kumar

Keyword(s):

Genetic Diversity ◽

Bread Wheat ◽

Diversity Analysis ◽

Wheat Varieties ◽

Genetic Diversity Analysis

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Investigation of Genetic Diversity among Bread Wheat Cultivars (Triticum aestivum L.) Using SSR Markers

Journal of Agricultural Science ◽

10.5539/jas.v5n1p122 ◽

2012 ◽

Vol 5 (1) ◽

Cited By ~ 1

Author(s):

Reza Drikvand ◽

Mohammad Reza Bihamta ◽

Goodarz Najafian ◽

Asa Ebrahimi

Keyword(s):

Genetic Diversity ◽

Triticum Aestivum ◽

Bread Wheat ◽

Ssr Markers ◽

Triticum Aestivum L ◽

Wheat Cultivars

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Functional gene assessment of bread wheat: breeding implications in Ningxia Province

BMC Plant Biology ◽

10.1186/s12870-021-02870-5 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Weijun Zhang ◽

Junjie Zhao ◽

Jinshang He ◽

Ling Kang ◽

Xiaoliang Wang ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Resources ◽

Bread Wheat ◽

Large Population ◽

Flow Analysis ◽

Wheat Breeding ◽

Wheat Varieties ◽

Genetic Components ◽

Yield Quality ◽

Genetic Distribution

Abstract Background The overall genetic distribution and divergence of cloned genes among bread wheat varieties that have occurred during the breeding process over the past few decades in Ningxia Province, China, are poorly understood. Here, we report the genetic diversities of 44 important genes related to grain yield, quality, adaptation and resistance in 121 Ningxia and 86 introduced wheat cultivars and advanced lines. Results The population structure indicated characteristics of genetic components of Ningxia wheat, including landraces of particular genetic resources, introduced varieties with rich genetic diversities and modern cultivars in different periods. Analysis of allele frequencies showed that the dwarfing alleles Rht-B1b at Rht-B1 and Rht-D1b at Rht-D1, 1BL/1RS translocation, Hap-1 at GW2-6B and Hap-H at Sus2-2B are very frequently present in modern Ningxia cultivars and in introduced varieties from other regions but absent in landraces. This indicates that the introduced wheat germplasm with numerous beneficial genes is vital for broadening the genetic diversity of Ningxia wheat varieties. Large population differentiation between modern cultivars and landraces has occurred in adaptation genes. Founder parents carry excellent allele combinations of important genes, with a higher number of favorable alleles than modern cultivars. Gene flow analysis showed that six founder parents have greatly contributed to breeding improvement in Ningxia Province, particularly Zhou 8425B, for yield-related genes. Conclusions Varieties introduced from other regions with rich genetic diversity and landraces with well-adapted genetic resources have been applied to improve modern cultivars. Founder parents, particularly Zhou 8425B, for yield-related genes have contributed greatly to wheat breeding improvement in Ningxia Province. These findings will greatly benefit bread wheat breeding in Ningxia Province as well as other areas with similar ecological environments.

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Investigation of Genetic Diversity in Afghan Bread Wheat Genotypes Using SSR and AFLP Markers

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v7i9.1263-1267.2165 ◽

2019 ◽

Vol 7 (9) ◽

pp. 1263

Author(s):

Mohammad Bahman Sadeqi ◽

Said Dadshani ◽

Mohammad Yousefi ◽

Gul Mohammad Ajir

Keyword(s):

Genetic Diversity ◽

Bread Wheat ◽

Ssr Markers ◽

Average Distance ◽

Wheat Breeding ◽

Aflp Markers ◽

Ammonium Bromide ◽

Aflp Data ◽

Wheat Genotypes ◽

Diversity Assessment

Genetic diversity assessment is the principle component for conservation and characterization of germplasm. Genetic diversity study of Afghan bread wheat genotypes is a first step to identify and to select high performance genotypes and distribute to wheat breeding programs. The main objective of this study is to investigate of genetic diversity in 35 Afghan bread wheat genotypes by using Simple Sequence Repeat (SSR) and Amplified Fragment Length Polymorphism (AFLP) markers. DNA extraction according to Cetyl Trimethyl Ammonium Bromide (CTAB) method was conducted and the total genomic DNA was isolated from each variety. Sixty-four SSR primer markers were used and eighteen EcoRI+(N)/MseI+(N) primer combinations with their primer sequences were used for selective polymerase chain reaction (PCR) amplification. Every SSR and AFLP fragment was scored as present (1) or absent (0) within all genotypes under study. Marker/ Value ratio of pairwise genetic distance between genotypes according to the SSRs data was from 0.508 to 0.691 with an average distance of 0.599. Relatively different grouping pattern in comparison to AFLP data observed through cluster analysis. Both types of molecular markers (AFLP and SSR) used in this research proved to be suitable for investigating genetic diversity in the genotypes of Afghan bread wheat, however, AFLP markers gave better view of genetically relationships among genotypes than the SSR markers. The grouping generated by AFLP data showed a special agreement with the origin regions of genotypes (Ariana-07 and Mazar-99 originating from the north of Afghanistan, Lalmi-03 and Kabul-02. Large number of DNA bands identified with AFLP markers might provide a better estimation of genetic similarity than those of SSR markers.

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The impact of breeding on genetic diversity and erosion in bread wheat

Plant Genetic Resources ◽

10.1079/pgr200593 ◽

2005 ◽

Vol 3 (3) ◽

pp. 391-399 ◽

Cited By ~ 3

Author(s):

Paolo Donini ◽

John R. Law ◽

Robert M. D. Koebner ◽

James C. Reeves ◽

Robert J. Cooke

Keyword(s):

Genetic Diversity ◽

Bread Wheat ◽

Morphological Characteristics ◽

Wheat Varieties ◽

Time Period ◽

Ssr Loci ◽

Genetic Pool ◽

The Uk ◽

Dna Microsatellite ◽

The Impact

This paper examines the fate of alleles and changes of genetic diversity in old (ca 1930s) versus more modern (ca 1990s) UK bread wheat varieties using 14 mapped DNA microsatellite (simple sequence repeat, SSR) loci and morphological markers. The allelic constitution of varieties belonging to three time periods (early, intermediate, late) was determined. While at certain loci one or more SSR alleles were gained between early and late periods, at others the allelic representation remained constant, although a shift in allelic frequencies could sometimes be detected. No locus showed a clear, net loss in the total number of alleles over the time period. In a further group of loci, there was neither clear gain nor loss, but rather a dynamic flux of alleles. A comparison of the allelic constitution of the UK variety set with a larger genetic pool (non-UK varieties) showed that some loci were rather similar in allelic constitution, while others possessed additional diversity. Certain SSR alleles appeared to be associated with old or modern varieties, possibly indicating associations with chromosome regions under selection pressure. The same exercise was conducted on the basis of 14 of the morphological characteristics recorded in the course of distinctness, uniformity and stability testing of varieties. Overall, this analysis generated a similar picture of changes in diversity to that obtained from the microsatellite data.

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