Polymorphism Information Content Research Articles

Microsatellite based molecular characterization of Nattukuttai- a unique short statured Bos indicus cattle population of southern India.

Molecular characterization was conducted to characterise 'Nattukuttai', a native cattle population of the north-eastern agro-climatic zone of Tamil Nadu (India), using thirty microsatellite markers. The analyses revealed a high level of genetic diversity, with a total of 294 alleles observed across all the loci, averaging 9.8 alleles per locus. The allele sizes ranged from 83bp to 302bp, with frequencies ranging from 0.010 to 0.875. The microsatellite markers demonstrated high polymorphism, as indicated by an average polymorphic information content (PIC) of 0.763. Deviation from Hardy-Weinberg equilibrium was observed in a significant number of loci, indicating possible genetic influences such as selection or population structure. Bottleneck analysis suggested that the Nattukuttai population did not undergo any recent significant population contraction. Comparative analyses with three other cattle populations (Kangayam, Malai Madu, and Malnad Gidda) revealed varying genetic distances. Nattukuttai showed a distinct genetic profile, diverging from a common source that also gave rise to the Kangayam and Malai Madu clusters. Multivariate statistical analyses and phylogenetic reconstruction supported the genetic differentiation of Nattukuttai from the other populations, while Malai Madu and Kangayam were found to be genetically closer to each other. Overall, these findings provide insights into the genetic structure and relationships of the Nattukuttai cattle population, highlighting its distinct genetic identity and potential conservation significance.

Assessment of genetic biodiversity and association of micronutrients and agronomic traits using microsatellites and staining methods which accelerates high-micronutrients variety selections within different wheat groups

Evaluation of genetic biodiversity for micronutrients is crucial for breeding high-quality crops and addressing the negative impacts of mineral deficiencies. The objectives of this research were to assess genetic variation and the relationship between grain Fe and Zn levels and agronomic traits in a diverse collection of wheat varieties. Additionally, the study aimed to determine the correlation between microsatellite markers (SSR) and micronutrient quantities. A total of 42 genotypes (Iranian commercial cultivars, landraces, and Afghan and Swiss varieties) were evaluated over a two-year period. Fe and Zn levels were measured using two semi quantitative staining assays and atomic absorption spectrophotometry (AAS) facility. Semi-quantitative staining methods and AAS showed high correlations for micronutrient contents. Landraces exhibited higher Fe (63.79 mg/kg) and Zn (44.76 mg/kg) but lower grain yield compared with commercial cultivars. Heritability estimates ranged 53%-79.43%, suggesting that genetic variance played a higher contribution in the phenotypic variation of traits than environmental factors. Notably, Fe content displayed significant correlations with days to maturity. Canonical correlation analysis (CCA) revealed that Zn content was correlated with four agronomic traits. Evaluation of genetic diversity using SSR markers demonstrated high genetic variation among the genotypes tested. The analysis of polymorphism information content (PIC) indicated that SSR primers had an average PIC of 0.75, with the Xgwm192 primer exhibiting higher PIC than others. Several SSR markers revealed association with micronutrient content that can be used in marker-assisted selection (MAS) programs aimed at selection of high micronutrient genotypes. In conclusion, the findings underscored the substantial genetic diversity present in micronutrient levels among global wheat genotypes, the potential of landraces for micronutrients biofortification of wheat cultivars through cross hybridization, the utility of staining methods for screening high/low micronutrient genotypes, and use of microsatellite markers for marker-assisted breeding aiming to micronutrient improvement in breeding programs.

Development of Microsatellite Markers from Transcriptome of Eriocheir sinensis and Their Application in Multiplex PCR Panels

Background: The development of genetic markers is crucial for aquaculture and population genetics. Polyallelic microsatellite markers are widely used for breeding and family management of Eriocheir sinensis (E. sinensis), contributing to the sustainable development of the industry. Methods: Through transcriptome analysis, 100 highly polymorphic SSR markers were identified and developed. From these, four multiplex PCR panels, each containing 16 markers, were constructed and applied to parentage assignment in six E. sinensis families. Results: The number of alleles (Na) ranged from 7 to 21, the observed heterozygosity (Ho) varied from 0.356 to 0.951, and the expected heterozygosity (He) varied from 0.656 to 0.909. The polymorphism information content (PIC) ranged from 0.633 to 0.900. The CERVUS analysis showed that using only the two most informative multiplex PCR panels, assignment success rates exceeded 90.34%, with 100% accuracy in assigning offspring to parents when three or four panels were used. Conclusions: This method significantly enhances the efficiency of microsatellite marker analysis, which provides a convenient and cost-effective method for breeding programs and family management of E. sinensis.

Harnessing genetic diversity in Sudanese sorghum wild relatives for stay-green drought tolerance via microsatellite (SSR) marker assessment

AbstractSudan is the birthplace of sorghum, and vast genetic diversity exists among its wild relatives. To assess the genetic potential of Sudan wild sorghum accessions, we used 41 stay-green-specific microsatellite (SSR) markers to analyze the genetic variability and population structure of 256 accessions. Overall, 17 SSR markers were polymorphic, with 55 alleles on average 3.3 per locus. The polymorphic information content (PIC) ranged from 0.49 to 0.57, with an overall mean of 0.53, indicating the potential of these markers for capturing the genetic construction of wild sorghum. Linkage disequilibrium analysis identified the two most informative markers, Xcup05 and Xtxp212. Accordingly, the Nei gene diversity of the populations varied from 0.032 to 0.127, with an overall mean of 0.083. Molecular variance analysis (AMOVA) demonstrated that 99% and 1% of the genetic variations were within and among populations (Fst = 0.066; P 0.001), respectively. However, gene flow (Nm) values varied from 0.058 in populations 1 and 2 to 1.018 in populations 2 and 3. Neighbor-joining trees identified from 21 Sudanese wild sorghum accessions clustered closely to the universally drought-tolerant landrace B35. Structural analysis generated the highest Delta K value (58.2) at K = 2, revealing two distinct subpopulations. While this work provides valuable information about the potential of sorghum wild relatives from Sudan as sources for stay-green drought tolerance, further research should be directed toward identifying the exact mechanisms and genes underlying this stay-green trait using advanced molecular omics techniques. In conclusion, this study highlights the potential role of Sudanese sorghum accessions as reservoirs of ready-to-use stay-green genes for the design of climate-resilient sorghum cultivars in drought-prone areas of Sudan and beyond. However, these wild relatives would require extensive pre-breeding and validation efforts before their genes can be effectively incorporated into elite cultivars.

Genetic diversity assessment of cucumber landraces using molecular signatures

Genetic profiling of the biodiversity in cultivated crop plants is necessary to preserve important genes and utilize them in a breeding program. Cucumber is used as a model plant to study various characteristics of Cucurbitaceae. Its adaptation to a wide range of climatic conditions suggested analyzing the landraces. The present study was conducted to evaluate the differences, at the genetic level, among landraces spanning five continents. DNA extracted from fifty-six landraces selected from USDA germplasm bank to cover a global representative sample of world cucumber landraces was used for polymerase chain reaction using twenty-eight polymorphic expressed sequence tags simple sequence repeat (EST-SSR) markers. Twenty-eight EST-SSR markers covering all seven chromosomes yielded 98 bands with an average of 3.42 bands per marker. Polymorphic information content ranged from 0.00 (EC35) to 0.74 (EC17) with an average of 0.34. Six clusters provided an appropriate summary of the variation among the landraces, with the two largest groups including 32 (Asiatic) and 17 (European and American) landraces, respectively. Four small groups, three with two members, and one with one member (PI 525155-Egypt) were dissimilar to the two main groups. Landraces from the same region were often clustered together. Genetic similarity of the landraces was revealed by marker banding patterns. The locations of genetic diversity for cucumber landraces can be identified from this study.

Morpho-molecular Genetic Diversity Analysis of Basmati and Non-basmati Rice (Oryza sativa L.) Germplasm

This study evaluated genetic variability and relatedness among 34 rice genotypes, encompassing basmati and non-basmati varieties using morphological and molecular data. The findings revealed significant variability across all traits assessed. High phenotypic and genotypic coefficients of variation (PCV and GCV) were observed for traits such as days to 50% flowering, days to maturity, biological yield, grain yield, test weight, flag leaf length, and number of effective tillers. Notably, high heritability and genetic advance indicated that these traits are likely influenced by additive gene effects, making them suitable for selection in breeding programs. D2 analysis confirmed substantial genetic diversity among the genotypes and five clusters were formed based on the morphological data. Molecular analysis using 13 SSR primers, out of 13 primers 11 primers are showed the banding pattern, with the highest polymorphism information content (PIC) value recorded at 0.79 for marker HvSSR04-46. Clustering based on Jaccard’s dissimilarity coefficient revealed two distinct clusters. Based on the dendrogram pattern molecular data is divided into two clusters, cluster I and Cluster II, cluster I is subdivided into Cluster Ia and Cluster Ib. This research was conducted at Sardar Vallabhbhai Patel University of Agricultural & Technology, Modipuram, Meerut, Uttar Pradesh, highlights the potential for selecting diverse rice genotypes to enhance breeding programs.

Microsatellite Markers & Mitochondrial D-Loop Based Phylogenetic And Diversity Analysis In Gabrali Cattle.

The Gabrali cattle is a multipurpose breed, native to Khyber Pakhtunkhwa, Pakistan. Despite its economic importance, scientific data about its phylogeny and genetic diversity is scarce. To address this issue, the present study was conducted on thirty (30) unrelated Gabrali male and female animals, from which blood samples were collected and DNA was extracted. Twelve (12) microsatellite loci and 1159bp of D-loop region were amplified via PCR and visualized on a 2% agarose gel. Sanger sequencing technique was used to sequence the D-loop amplicons. The microsatellite loci revealed 83 alleles with MNA (mean no of alleles per locus) = 8.8, the Ho (observed heterozygosity) and He (expected heterozygosity) of all loci were 0.58 and 0.50 respectively, mean PIC (Polymorphic Information content) = 0.59 and FIS (Inbreeding coefficient) = 0.056 using GeneAlEx® software. Microsatellite analysis revealed a normal allelic distribution across the breed, consistent with Hardy-Weinberg equilibrium. D-loop sequencing revealed eight haplotypes with 30 SNPs using DNA SP 6.0 software. High AT content was observed than GC content i.e. 55.9% and 44.1% respectively, while the transition to transversion ratio was R = 10:1. The value of Haplotype and Nucleotides diversity was Hd = 0.8601 ± SD = 0.0895 and Π = 0.0136 ± SD = 0.00197 respectively. Phylogenetic analysis done using Neighbor-joining method with bootstraps value of 1000, revealed the monophyletic clade of both Gabrali and Bos indicus haplotypes. Furthermore, the introgression of genes from national cattle breeds into Gabrali cattle was observed. It is concluded that Gabrali cattle have common ancestry with Bos indicus having no threats of genetic bottleneck having substantial genetic diversity.

Morphological and genetic characterization of mutants of Gladiolus cultivar prince of orange for two successive vegetative generations

Gladiolus mutants developed using gamma irradiations and EMS treatments were characterized using morphological, genetic and Polymerase Chain Reactions (PCR) based Inter-Simple Sequence Repeats (ISSR) for designing future breeding strategies. As many as 7 mutants based on phenotypic variations such as colour and shape modifications were subjected to molecular characterization using 11 ISSR primers that confirmed variations. ISSR markers showed 13.88 to 36.00 percent polymorphism among the mutants was recorded, signifying variability among different mutants. UPGMA (unweighted pair group method with arithmetic mean) based analysis of cluster separated gladiolus variety prince of orange mutants into four clusters. ISSR markers were subjected for comparative analysis like effective multiplex ratio, marker index, polymorphic information content and resolving power wherein, highest EMR (3.24), MI (1.32) were found for UBC 810, Rp (4.37) values were found for UBC 827, and maximum PIC value (0.46) for ISSR 22218 UBC 812. The results clearly indicated the reproducibility of ISSRs and their ability to detect variability among the mutants. A significant level of genetic variation was depicted by ANOVA which suggested the usefulness of studies in gladiolus breeding and unique bands obtained could be utilized for mutant/ varietal identification.

Research Note: Whole-genome sequencing revealed genomic diversity dynamics in duck conserved populations

The purpose of this study was to comprehensively analyze the genetic diversity of the Pekin duck conserved population with five generations and to evaluate the effectiveness of the current conservation strategy. In total, 277 Pekin duck conserved individuals and 40 Mallards as ancestral controls were collected. Each duck was sequenced at about 10X whole-genome coverage, while over 7.4 million single nucleotide polymorphisms (SNPs) in total were detected for genetic diversity analysis. Both the expected heterozygosity and observed heterozygosity values exceeded 0.3. The genetic differentiation (FST) values ranged from 0.007 to 0.039, and the Polymorphism information content (PIC) values ranged from 0.29 to 0.34. These results indicate no significant differentiation between generations, and the genetic diversity remains high. In particular, the inbreeding coefficient has been strictly controlled and has not increased rapidly during the conservation. Overall, the inbreeding coefficient of the conserved Pekin duck population was higher than that of its wild ancestors, indicating that domestication has resulted in reduced genetic diversity. This is the first report using whole genome resequencing data to systematically evaluate the genomic dynamics across several generations in ducks. The results show that the strategy of free mating and random seed retention within sire families is effective for maintaining the genetic diversity of the conserved Pekin duck population.

Genome-Wide Development and Characterization of Microsatellite Markers in the Great Web-Spinning Sawfly Acantholyda posticalis.

The great web-spinning sawfly Acantholyda posticalis is notorious for damaging Pinus forests across the Palearctic region. At present, uncertainties persist regarding its intraspecies variation and presumed subspecies. To use as tools for future studies, herein we developed genome-wide microsatellite markers for A. posticalis. Through searching, rigorous manual screening, and amplification trial, 56 microsatellite markers were obtained from the genome sequences. We characterized these markers across two populations from Shandong province (SD) and Heilongjiang province (HLJ) in China, and carried out cross-amplification in three related species. Out of the 56 markers tested, 10, 31, and 15 were categorized into high, moderate, and low polymorphic levels, respectively, based on their polymorphic information content (PIC) values. Meanwhile, 28, 19, and 4 microsatellite loci were successfully cross-amplified in Cephalcia yanqingensis, C. chuxiongica, and C. infumata, respectively, which could serve as potential molecular markers for their further studies. STRUCTURE and PCoA analyses revealed two distinct clusters corresponding to SD and HLJ, respectively, indicating a high resolution of these markers. Therefore，the 56 microsatellite markers identified here have the potential to serve as efficient tools for unraveling intraspecies variation and evolutionary history of A. posticalis.

Population structure and markers analysis associated with powdery mildew resistance in pumpkin, Cucurbita pepo L

Pumpkin (Cucurbita pepo L.) is an economically important vegetable and summer crop. The seeds have high nutritional value due to their edible oil and protein content with a high medicinal value. Pumpkin is attacked by several fungal diseases; one of which is powdery mildew (PM) caused by Podosphaera xanthii race-0. PM causes severe disease on pumpkin leading to major yield losses globally. In this study, we analyzed the genetic diversity and population structure of fourteen local pumpkin cultivars, all under Cucurbita pepo L. based on dominance in the region using 15 Inter-Simple-Sequence-Repeats-(ISSR) primer-pairs in association with resistance against PM as well as regulating the expression of three resistant marker genes i.e. SGT1, bHLH and PSK via qRT-PCR at three stages with 10 days' interval post-inoculation-stages-(SPI) with the powdery mildew agent, P. xanthii race-0. The results showed that ISSR markers demonstrated 13 primers out of 15 primers generated 169 distinct amplified bands, out of which 143 bands showed polymorphism. The mean polymorphism information content (PIC), marker index (MI), effective-number of alleles (I), expected heterozygosity (H), and Nei's gene diversity parameters were 0.354, 3.344, 0.334, 0.205 and 0.200, respectively. According to PIC, MI, I, H, and Nei indices evaluation, ISSR10 primer had the best performance in genetic diversity of the related pumpkin population. NTSYS pc 2.02e software and several similarity coefficients (r = 0.964), placed the related genotypes into five distinct groups. Of which, ‘Maragheh1′ and ‘Shahreza’ as resistant ones with 9.4 % and 6.1 % disease severity (DS), and ‘Gorgan’, ‘Urmia1′ and 3 and ‘Maragheh3’ with 79.6–84.8 % DS, as susceptible ones into two distinct groups, respectively. Further, the marker genes SGT1, bHLH and PSK expression level changes showed that the effect of variable factors including different genotypes (susceptible and resistant), disease-causing fungus, SPI, and the mutual effect of these factors is significant with the highest increase in resistant genotypes. Considering the relative compatibility in the classification of pumpkin genotypes in the dendrograms of DS and ISSR markers, it can be expected that increasing the number of markers in evaluating the genetic diversity of these genotypes makes it possible to differentiate pumpkin genotypes resistant and susceptible to PM disease based on the degree of disease resistance. The markers associated with resistance are recommended for use in marker assisted breeding.

Analysis of Inter-Primer Binding Site Retrotransposon Length Polymorphism in Selected Group of Vaccinium corymbosum

Abstract The genetic variability in 13 selected genotypes of Vaccinium corymbosum using re-trotransposon-based iPBS markers system was characterized in this study. The four selected iPBS primers amplified 232 fragments, average 58 fragments per primer, approximately 53.16% of which were polymorphic. The polymorphism information content of iPBS marker was 0.238. The hierarchical cluster using unweighted pair group method with arithmetic mean analysis divided selected genotypes into two main groups and several subgroups. The values of the Jaccard coefficient of genetic relatedness were between 0.036–0.243. The similarity between two sample sets was 3.6%–24.3%. This study confirmed inter-PBS amplification technique as a reproducible and trustable marker system, but has proved to be an effective DNA fingerprinting technology to generate polymorphism in Vaccinium corymbosum.

Development of Simple Sequence Repeat of Monochamus alternatus (Coleoptera: Cerambycidae) Based on Restriction Site-Associated DNA Sequencing

Monochamus alternatus, a pest posing a serious threat to coniferous species, such as Pinus massoniana, has had devastating effects on pine forests due to its association with Bursaphelenchus xylophilus. The creation of unique simple sequence repeat (SSR) primers for M. alternatus is crucial, as there has been little study of the species’ phylogeography. The aim of this study was to identify and create polymorphic SSR primers by sequencing samples of M. alternatus obtained from three different sampling points using the restriction site-associated DNA sequencing (Red-seq) approach. Subsequently, supplementary samples were integrated, and genetic typing was performed utilizing the identified polymorphic primers. Through comprehensive analysis, a total of 95,612 SSR loci were identified. Among these, mononucleotide repeats (51.43%), dinucleotide repeats (28.79%), and trinucleotide repeats (16.74%) predominated among the SSR motif types. Ultimately, 18 pairs of SSR primers were screened out, demonstrating stable amplification and high polymorphism. Genetic typing revealed that the mean number of alleles (Na) for these primer pairs ranged from 3 to 8, observed heterozygosity (Ho) ranged from 0.133 to 0.733, polymorphic information content (PIC) ranged from 0.294 and 0.783, and Shannon’s index (I) ranged from 0.590 to 1.802. This study effectively produced 16 pairs of SSR primers that can be applied to different populations of M. alternatus. As a result, important tools for furthering studies on the phylogeography of pine wood nematodes, creating genetic maps, gene mapping, and carrying out in-depth investigations into gene function have been made available.

The impact of LEP gene polymorphisms located at exon 2 (LEP-HinfI) and intron 2 (LEP-Sau3AI) on growth and reproductive traits in Saanen goats

Abstract. Leptin (LEP), alternatively recognized as the obesity gene, influences food consumption, energy balance, and lipid metabolism. Additionally, it plays a crucial role in energy metabolism, and variations in the LEP gene have been studied extensively among various livestock species. These investigations have unveiled correlations with traits such as meat quality, milk yield and composition, and growth characteristics. Nevertheless, the existing knowledge regarding its correlation with growth and reproductive traits in goats is comparatively limited, particularly when juxtaposed with studies of cattle. Hence, the objective of the current study was to investigate the relationship between polymorphisms in the intron 2 (Sau3AI) and exon 2 (HinfI) regions of the LEP gene and growth and reproductive traits in Saanen goats. The study comprised 185 Saanen goats in total. The PCR-RFLP (polymerase chain reaction restriction fragment length polymorphism) technique was employed to genotype these polymorphisms. Population genetic analysis included the number of effective alleles, heterozygosity, polymorphism information content, and compatibility with the Hardy–Weinberg equilibrium. The general linear model procedure's least-squares methods were used for the statistical analysis. The SNP (single-nucleotide polymorphism) located in exon 2 (LEP-HinfI) was monomorphic. Remarkably, the SNP located in intron 2 (LEP-Sau3AI) was associated with birth weight (p<0.05) and average daily weight gain (p<0.05). In this context, the AA genotype demonstrated higher birth weight and daily live weight gain means compared to other genotypes. No significant differences were observed in litter size, total weight gain, or morphometric measurements. The caprine LEP-Sau3AI polymorphism situated within intron 2 proved influential in traits critical for the profitability and sustainability of goat breeding. The findings of this study provide novel and valuable information for future research on the LEP gene in goats.

Utilizing SSR-based core collection development to improve conservation and utilization of Corylus L. genetic resources.

Hazelnuts are traditional woody oilseed plants. Corylus L. resources are rich in variety and widely distributed in China. However, the identification of germplasm varieties and the selection of superior varieties remain quite limited. This study aimed to analyze the genetic diversity of 331 Corylus L. germplasms using 16 simple sequence repeat (SSR) markers. Based on this, 11 pairs of core primers were selected, a fingerprint database of germplasm resources was constructed, and a primary core collection was screened. The results indicated that these tested Corylus L. germplasms exhibited a high level of genetic diversity, with an average number of alleles (Na) per locus of 14.5 and a polymorphic information content of 0.777. The phylogenetic relationships among various hazelnut cultivars were characterized by complexity, and they were delineated into four distinct groups facilitated by genetic distance analyses. An SSR fingerprint database for 331 Corylus L. germplasms was successfully constructed using the 11 obtained core SSR markers to increase the discrimination efficiency. Ultimately, 127 primary core accessions of Corylus L. were selected. The retention rate for the observed Na and MAF (the minor allele frequency) in the primary core germplasm constructed based on a sampling proportion of 38.36% was 100% and 94.7%, respectively. Shannon's information index (I) was highly consistent between the core and original germplasms, indicating that the core germplasm could fully represent the genetic diversity of the original germplasm. Additionally, the principal coordinate analysis of the selected primary core germplasm was essentially consistent with that of the entire original germplasm, further supporting the broad representativeness of the core germplasm. This study provided a basis for precisely identifying and efficiently utilizing Corylus L. accession.

Genetic Diversity and Association Analysis of Traits Related to Water-Use Efficiency and Nitrogen-Use Efficiency of Populus deltoides Based on SSR Markers.

Populus deltoides is one of the primary tree species for bioenergy production in temperate regions. In arid/semi-arid northern China, the scarcity of water and nitrogen significantly limits the productivity of poplar plantations. The identification of relevant molecular markers can promote the breeding of resource-efficient varieties. In this study, 188 genotypes of P. deltoides from six provenances served as experimental material. Genetic differentiation analysis, analysis of molecular variance (AMOVA), principal coordinate analysis (PCoA), unweighted pair group method with arithmetic mean (UPGMA) clustering, and genetic structure analysis were performed using selected simple sequence repeat (SSR) markers. Based on these analyses, the association analysis of water-use efficiency (WUE) and nitrogen-use efficiency (NUE) were conducted using general linear model (GLM) and mixed linear model (MLM) approaches. The results showed that 15 pairs of SSR primers successfully amplified across all 188 individuals, with an average of 7.33 alleles (Na) observed per primer pair. The polymorphism information content (PIC) ranged from 0.060 to 0.897, with an average of 0.544, indicating high genetic diversity in the selected markers. The average inbreeding coefficient intra-population (Fis), inbreeding coefficient inter-population (Fit), and inter-population genetic fraction coefficient (Fst) values were 0.005, 0.135, and 0.132, respectively, indicating high heterozygosity, substantial inbreeding within populations, and moderate genetic differentiation, with an average gene flow (Nm) of 1.964, suggesting substantial gene flow between populations. Additionally, molecular variance was primarily within individuals (84.12%). Genetic structure analysis revealed four subgroups, with some degree of genetic admixture among the provenances. In the GLM model, 11 markers were significantly associated with five traits (p < 0.05), with an average contribution rate of 15.82%. Notably, SSR132 and SSR143 were significantly associated with multiple traits (p < 0.05). The MLM model identified two markers (SSR47 and SSR85) significantly associated with ground diameter (p < 0.05) and one marker (SSR80) significantly associated with NUE (p < 0.05). This study identifies loci associated with WUE and NUE, laying a foundation for future genetic improvement and marker-assisted breeding strategies in poplar.

Genetic Diversity and Population Structure Analysis of Soybean [Glycine max (L.) Merrill] Genotypes Using Agro-Morphological Traits and SNP Markers

Background/Objectives: Understanding the genetic diversity of soybean genotypes can provide valuable information that guides parental selection and the design of an effective hybridization strategy in a soybean breeding program. In order to identify genetically diverse, complementary, and prospective parental lines for breeding, this study set out to ascertain the genetic diversity, relationships, and population structure among 35 soybean genotypes based on agro-morphological traits and Single Nucleotide Polymorphic (SNP) marker data. Methods/Results: Cluster analysis, based on agro-morphological traits, grouped the studied genotypes into four clusters. The first two principal components accounted for 62.8% of the total phenotypic variation, where days to 50% flowering, days to 95% maturity, grain yield, shattering score, and lodging score had high and positive contributions to the total variation. Using the SNP marker information, mean values of 0.16, 0.19, 0.067, and 0.227 were obtained for minor allele frequency (MAF), polymorphic information content (PIC), observed heterozygosity (Ho), and expected heterozygosity (He), respectively. Using different clustering approaches (admixture population structure, principal component scatter plot, and hierarchical clustering), the studied genotypes were grouped into four major clusters. Conclusions:The agro-morphological and molecular analysis results indicated the existence of moderate genetic diversity among the studied genotypes. The traits identified to be significantly related to yield provide valuable information for the genetic improvement of soybeans for yield.

Genetic diversity and fingerprinting of Elaeagnus angustifolia based on SSR molecular markers

DNA fingerprinting can reveal the genetic diversity of Elaeagnus angustifolia germplasm resources and clarify the source and genetic background of E. angustifolia germplasm, which are the preconditions for the breeding of new varieties, the identification and protection of germplasm resources, and the comprehensive development of the E. angustifolia industry considering both ecological and economic benefits. We employed 11 pairs of primers with high polymorphism, clear bands, and high reproducibility to analyze the genetic diversity of 150 E. angustifolia germplasm accessions from Gansu and Beijing by the simple sequence repeat (SSR) molecular markers. We then employed the unweighted pair-group method with arithmetic means (UPGMA) to perform the cluster analysis based on genetic distance and analyzed the genetic structure of the 150 germplasm accessions based on a Bayesian model in Structure v2.3.3. The genetic diversity analysis revealed the mean number of alleles (Na) of 7.636 4, the mean number of effective alleles (Ne) of 2.832 6, the mean Shannon genetic diversity index (I) of 1.178 1, the mean Nei's gene diversity index (H) of 0.582 1, the mean observed heterozygosity (Ho) of 0.489 9, the mean expected heterozygosity (He) of 0.584 0, the mean polymorphism information content (PIC) of 0.535 4, and the mean genetic similarity (GS) of 0.831 5. These results suggested that the E. angustifolia germplasm resources we studied exhibited significant genetic differences and rich genetic diversity. The cluster analysis revealed that the tested materials can be classified into 3 groups, with the main genetic distance (GD) of 0.422 9. The clustering results were not completely consistent with the geographic origin. The population structure analysis classified the germplasm accessions into 2 populations. We used 8 pairs of primers with high PIC to construct the fingerprints of 150 E. angustifolia germplasm accessions. The present study successfully constructs the DNA fingerprints and clarified the genetic relationship of the E. angustifolia germplasm resources in Gansu and Beijing, providing a theoretical basis for germplasm resource identification, breeding of elite varieties, application in gardening, and molecular-assisted breeding of E. angustifolia.

The genetic diversity and population structure of wild and cultivated Avena species in Ethiopia using a SSR markers

Oats are grains that can be consumed by both animals and humans. They have thrived in Ethiopia, where certain oat species are considered native to the region. This work represents the first investigation of the population structure and genetic diversity of Ethiopian and other country oats. This led the scientists to explore the genetic diversity and population structure of wild and cultivated Ethiopian oats (Avena) species as well as oat cultivated in USA, the Netherlands and Austria. This study's main objective looks to be to investigate the variation in genetic makeup of cultivated and wild oat species. Studying the population structure of the oat species in the germplasm of Ethiopia, USA, the Netherlands and Austria. We used nineteen fluorescent SSR (simple sequence repeat) markers since previous research had indicated that these markers had high PIC (polymorphism information content) values. Five species of Avena were studied among the 176 oat accessions: A. sativa (cultivated oats) and four wild oats, such as A. abyssinica, A. vaviloviana, A. fatua, and A. sterilis. The AMOVA investigation revealed significant genetic distinctions among populations, individuals, and within individuals, explaining 18 % of the variance within populations, 4 % among populations, and 78 % within individuals. The AMOVA analysis of Avena species demonstrated extensive variance, with 33 % variation among species and 67 % within each species, underscoring robust species differentiation. The study also discovered gene interchange between wild oat and cultivated populations, defining two Avena species: domesticated oats and wild oats. Using the STRUCTURE software at K = 2, PCoA, and UPGMA, a distinct genetic structure was displayed in the dataset. Despite variations in ploidy levels and genomes, A. sterilis and A. vaviloviana were determined to be more closely linked, whereas A. abyssinica and A. fatua demonstrated a close association. This research delivers valuable insights for scientists and can be employed in oat breeding programs to improve future oat yield and productivity.

Assessment of Genetic Diversity and Population Structure of Exotic Sugar Beet (Beta vulgaris L.) Varieties Using Three Molecular Markers.

Sugar beet (Beta vulgaris L.) is a biennial herb belonging to the Amaranthaceae family. It contributes to approximately 30% of the world's total sucrose production and is an economically important crop. In this study, we analyzed the genetic diversity and population structure of 132 exotic sugar beet varieties using three molecular makers: four pairs of simple sequence repeat (SSR) primers, three pairs of insertion-deletion sequence (InDel) primers, and 20 cis-element amplification polymorphism (CEAP) primers. The results indicated that the number of alleles (Na) was 298, among which the number of effective alleles (Ne) was 182.426 (accounting for approximately 61.2%). The mean value of the genetic diversity index was 0.836. The polymorphic information content (PIC) was 0.639-0.907 (mean = 0.819), indicating a high level of polymorphism. These sugar beet varieties were classified into six clusters using the UPGMA method of cluster analysis. Population structure analysis revealed that the most ideal K value was 6. This indicated that the test materials could be divided into six categories, consistent with the clustering results. The clustering results indicated that most sugar beet varieties from the same breeding company clustered together, and the genetic distance between them was small, indicating that they may share the same male and/or female parent. Some varieties from different companies clustered together, indicating a narrow genetic base and potential exchange of germplasm resources between breeding companies. This study revealed the genetic differences among exotic sugar beet varieties and characteristics of the population structure. It provided a scientific basis for the identification of sugar beet varieties and markers-assisted breeding in China in the future.