Analysis Of Genetic Relationships Research Articles

Genetic relationship analysis and fingerprint construction of some species in the genus Vanda (Orchidaceae) by interprimer binding site (iPBS) markers

Genetic relationship analysis and fingerprint construction of some species in the genus Vanda (Orchidaceae) by interprimer binding site (iPBS) markers

Identification of the 18 World War II executed citizens of Adele, Rethymnon, Crete using an ancient DNA approach and low coverage genomes

In the Battle of Crete during the World War II occupation of Greece, the German forces faced substantial civilian resistance. To retribute the numerous German losses, a series of mass executions took place in numerous places in Crete; a common practice reported from Greece and elsewhere. In Adele, a village in the regional unit of Rethymnon, 18 male civilians were executed and buried in a burial pit at the Sarakina site. In this study, the first one conducted for a conflict that occurred in Greece, we identified for humanitarian purposes the 18 skulls of the Sarakina victims, following a request from the local community of Adele. The molecular identification of historical human remains via ancient DNA approaches and low coverage whole genome sequencing has only recently been introduced. Here, we performed genome skimming on the living relatives of the victims, as well as high throughput historical DNA analysis on the skulls to infer the kinship degrees among the victims via genetic relatedness analyses. We also conducted targeted anthropological analysis to successfully complete the identification of all Sarakina victims. We demonstrate that our methodological approach constitutes a potentially highly informative forensic tool to identify war victims. It can hence be applied to analogous studies on degraded DNA, thus, paving the path for systematic war victim identification in Greece and beyond.

Phenotypic Characteristics, Pathogenicity, and Molecular Identification of Hypomyces perniciosus Causing Wet Bubble Disease of Edible Mushrooms

Abstract The research aimed to determine the phenotypic characteristic, pathogenicity and molecular characterization of Hypomyces perniciosus isolates responsible for wet bubble disease of the white button mushroom Agaricus bisporus. Phenotypic characteristics such as colony appearance, mycelium texture, and pigmentation were studied on four different agar media, i.e., potato dextrose agar (PDA), malt extract agar (MEA), Czapek-Dox yeast agar (CYA), and Sabouraud dextrose agar (SDA), after eight days of incubation. Additionally, the growth rate of the tested isolates was studied depending on the pH of the medium. Fungal isolates showed the highest mycelial growth on MEA and SDA at pH 6.0. However, on CYA at pH 7.0, the mycelium exhibited the worst growth. Isolate identification and genetic relationship analysis were carried out using internal transcribed spacer region sequencing and the random amplified polymorphic DNA method. The research confirmed that all Polish isolates belong to the species H. perniciosus, and the genetic diversity is relatively low. Phylogenetic analyses revealed three subgroups of H. perniciosus isolates. The first group included three genetically distinct isolates with a similarity coefficient in the range of 0.76–0.85 to isolates CBS 815.73 and CBS 322.52. The second group was divided into two subgroups and included 16 isolates with a genetic similarity range of 0.91 to 1.0 to CBS 815.73 and CBS 322.52 isolates. Furthermore, the eight genetically similar isolates exhibited the greatest pathogenicity towards A. bisporus.

Directional Breeding Generates Distinct Genetic Diversity in Hybrid Turf Bermudagrass as Probed with Simple Sequence Repeat Markers

Bermudagrass (Cynodon spp.) is a drought-resistant warm-season turfgrass adapted to the southern and transitional zones in the United States. Multiple hybrid cultivars have been developed and released for use as turfgrass, and others are still undergoing development. Increasing genetic diversity of commercial cultivars is vital to stress tolerance. A DNA profiling study of 21 experimental selections from the Oklahoma State University turfgrass breeding program and 11 cultivars was conducted using 51 simple sequence repeat primer pairs across the bermudagrass genome. A pairwise genetic relationship analysis of the genotypes using 352 polymorphic bands showed genetic similarity coefficients ranging from 0.59 to 0.89. The average pairwise population differentiation values were 0.012 for the 11 cultivars and 0.169 for the 21 selections. A cluster analysis using the unweighted paired group with the arithmetic average method grouped the entries into six clusters. A correlation analysis identified different levels of pairwise genetic relationships among the entries that largely reflected parental relationship. Directional breeding and selection for cold hardiness or drought resistance created progeny that had distinct genetic diversity in the tested bermudagrasses. It is evident that an increase in genetic diversity of the existing cultivar pool with the release of one or more experimental selections for commercial use will strengthen and improve bermudagrass systems.

Evolutionary dynamics and comparative pathogenicity of clade 2.3.4.4b H5 subtype avian influenza viruses, China, 2021–2022

The recent concurrent emergence of H5N1, H5N6, and H5N8 avian influenza viruses (AIVs) has led to significant avian mortality globally. Since 2020, frequent human-animal interactions have been documented. To gain insight into the novel H5 subtype AIVs (i.e., H5N1, H5N6 and H5N8), we collected 6102 samples from various regions of China between January 2021 and September 2022, and identified 41 H5Nx strains. Comparative analyses on the evolution and biological properties of these isolates were conducted. Phylogenetic analysis revealed that the 41 H5Nx strains belonged to clade 2.3.4.4b, with 13 related to H5N1, 19 to H5N6, and 9 to H5N8. Analysis based on global 2.3.4.4b viruses showed that all the viruses described in this study were likely originated from H5N8, exhibiting a heterogeneous evolutionary history between H5N1 and H5N6 during 2015–2022 worldwide. H5N1 showed a higher rate of evolution in 2021–2022 and more sites under positive selection pressure in 2015–2022. The antigenic profiles of the novel H5N1 and H5N6 exhibited notable variations. Further hemagglutination inhibition assay suggested that some A(H5N1) viruses may be antigenically distinct from the circulating H5N6 and H5N8 strains. Mammalian challenge assays demonstrated that the H5N8 virus (21GD001_H5N8) displayed the highest pathogenicity in mice, followed by the H5N1 virus (B1557_H5N1) and then the H5N6 virus (220086_H5N6), suggesting a heterogeneous virulence profile of H5 AIVs in the mammalian hosts. Based on the above results, we speculate that A(H5N1) viruses have a higher risk of emergence in the future. Collectively, these findings unveil a new landscape of different evolutionary history and biological characteristics of novel H5 AIVs in clade 2.3.4.4b, contributing to a better understanding of designing more effective strategies for the prevention and control of novel H5 AIVs.

SSR Marker–Based Genetic Diversity and Relationship Analyses of Stephania tetrandra S. Moore

AbstractStephania tetrandra S. Moore (family: Menispermaceae), a dioecious herbaceous vine and the only species in the subgenus Botryodiscia of the genus Stephania of the family Menispermaceae, is mainly distributed in hilly areas south of the Huaihe River in China and found in many provinces of China, showing a high genetic diversity. This paper aimed to study genetic diversity of and genetic relationship among individuals of S. tetrandra within China to provide a basis for evaluation, exploitation, and utilization of S. tetrandra by using simple sequence repeat (SSR) molecular markers. Our results show that effective products were amplified from the 26 screened SSR gene loci, a total of 183 alleles amplified (2–16 alleles amplified by each pair of primers). Among the 26 loci, 16 had a PIC value higher than 0.5, indicating a high level of polymorphism. For most of the loci, the number of effective alleles was lower than that of the observed alleles, and the observed heterozygosity was lower than the expected heterozygosity. The genetic differentiation coefficient (0.021–0.547) was lower than 0.05 (low level of genetic differentiation) for 7 loci and higher than 0.25 (very high level of genetic differentiation) for 2 loci, and had a value representing a medium level of genetic differentiation for the remaining 17 loci. The intra-population inbreeding coefficient had a positive value for 21 loci, suggesting the presence of inbreeding and homozygous excess. The gene flow value was bigger than 1, indicating that genetic drift and natural selection played an unimportant role in population genetic differentiation of S. tetrandra. Based on discriminant analysis of principal components and Bayesian Information Criterion, K-means clustering was performed on 620 samples. These samples were divided into 9 genetic clusters, whose similarity coefficients and genetic distances were 0.755–0.918 and 0.067–0.280, respectively, indicating that these clusters were highly similar and short-distanced. The Bayesian clustering analysis was implemented in the STRUCTURE software to analyze the genetic structure of S. tetrandra and it was found that the 620 samples could be clustered into 5 ancestor groups; the 9 clusters and 40 natural populations inherited genes from the 5 groups to varying degrees, but the proportion of genes inherited from the 5 groups by each cluster and natural population differed. S. tetrandra was characterized by the presence of population structure and pronounced genetic subdivision, which, together with the presence of gene flow, may indicate a relatively stable recent state of these populations.

Characterization of the chloroplast genome sequence of Calophyllum inophyllum, a bioenergy tree species, using Oxford Nanopore Technologies

Calophyllum inophyllum is a forest tree species that offers significant renewable energy benefits. However, the genetic information of these bioenergy tree species for the study of tree improvement is still limited. This study aimed to assemble the draft chloroplast genome using MinION Oxford Nanopore Technologies (ONT) and analyze the genetic relationship based on molecular markers for C. inophyllum. The study involved several steps: DNA extraction and isolation using the CTAB method, DNA library preparation, DNA sequencing using MinION Oxford Nanopore Technologies (ONT), and phylogenetic analysis based on selected DNA markers. The results showed that 115.1 Mb of high-quality DNA was successfully generated using ONT long-read sequencing, and 114.708 bp was annotated into partial genome chloroplast. The genetic relationship analysis using two selected DNA barcodes, namely rbcL and accD showed that the accD gene is more recommended for constructing a phylogenetic tree for the genus Calophyllum than the rbcL gene as it has a high bootstrap value (93%). Furthermore, the accD gene can also be considered a potential marker for further genetic analysis of C. inophyllum.

Analysis of genetic relationships between broomrape populations from different countries using ISSR markers

Orobanche cumana, commonly known as sunflower broomrape, poses a significant risk to sunflower cultivation in areas located along the Black Sea and across Europe. A study was conducted to analyze the genetic diversity and differentiation among populations of this parasitic plant originating from Bulgaria, Turkey, Republic of Moldova, and Romania. A total of 269 individuals from 23 populations were genotyped using 13 ISSR markers. The frequency distribution of alleles in the broomrape populations from Romania, Turkey and Bulgaria is more homogeneous than that from Moldavian populations. However, according to genetic diversity parameters O. cumana populations from Moldova and Turkey were more variable (total gene diversity Ht=0.188; 0.214), than those from Bulgaria and Romania (Ht=0.112; 0.067). The highest values of gene diversity within populations (Hs = 0.138) were found in Turkish broomrape. The value of Gst ranged between 0.359-0.516, indicating a very high level of genetic differentiation among populations. These results are consistent with low Nm values (0.468-0.895). Pairwise differentiation index (PhiPT) and Nei’s unbiased measures of genetic distance (GD) showed similar patterns, indicating a maximum (PhiPT=0.500; GD=0.261) and, respectively, minimum (PhiPT=0.238; GD=0.079) values between broomrape from Turkey and Romania, respectively, Romania and Moldova. Dendrogram constructed using the UPMGA method based on Nei's genetic distances and Pearson's dissimilarity clustered together Moldavian and Romanian broomrape and grouped in two separate clusters populations belonging to Bulgaria and Turkey. The PCA analysis confirmed the results of UPGMA clusterization. Overall, both methods suggest that the groupings of broomrape are partly determined by its geographical origin, as well as by the genetic differences and similarities accumulated over time, and are not related to virulence.

Distribution and conservation of simple sequence repeats in plant pathogenic species of Zymoseptoria and development of genomic resources for its orphaned species.

To better understand the structure and evolution of the genomes of four plant pathogenic species of Zymoseptoria, we analyzed the occurrence, relative abundance (RA), and density (RD) of simple sequence repeats (SSRs) in their whole genome and transcriptome sequences. In this study, SSRs are defined as repeats of more than 12 bases in length. The genome and transcriptome sequences of Zymoseptoria ardabiliae show the highest RA (201.1 and 129.9) and RD (3229.4 and 1928.2) of SSRs, while those of Zymoseptoria pseudotritici show the lowest RA (167.2 and 118.5) and RD (2482.2 and 1687.0). The majority of SSRs in the genomic and transcriptome sequences of species were trinucleotide SSRs, while dinucleotide SSRs were the least common. The most common trinucleotide motifs in the transcriptomic sequences across all species were those that encoded the amino acid arginine. As per our motif conservation study, Zymoseptoria tritici (12.4%) possessed the most unique motifs, while Z. pseudotritici (3.9%) had the fewest. Overall, only 38.1% of the motifs were found to be conserved among the species. Gene enrichment studies reveal that three of the species, Z. ardabiliae, Zymoseptoria brevis, and Z. pseudotritici, have SSRs in their genes related to cellular metabolism, while the remaining Z. tritici harbors SSRs in genes related to DNA synthesis and gene expression. In an effort to improve the genetic resources for the orphan species of pathogenic Zymoseptoria, a total of 73,134 primers were created. The genomic resources developed in this study could help with analyses of genetic relatedness within the population and the development of species-specific markers.

Medicinal Value, Genetic Diversity, and Genetic Relationship Analysis of Auricularia cornea (Agaricomycetes) Based on ITS, ISSR, and SRAP Markers.

Wild resources of Auricularia cornea (A. polytricha) are abundant in China, and genetic diversity and genetic relationships analysis of A. cornea can provide basis for germplasm resource utilization and innovation and molecular marker-assisted breeding. In this study, 22 Auricularia strains collected were identified as A. cornea based on ITS sequence analysis, and its genetic diversity was examined by ISSR and SRAP markers. The results showed that a total of 415 bands were amplified by 11 selected ISSR primers, with an average amplification of 37.73 bands per primer, and the mean values of Ne, I, and H were 1.302, 0.368, and 0.219, respectively. A total of 450 bands were amplified by 10 SRAP primers, with an average of 45 bands per primer, and the average of Ne, I, and H were 1.263, 0.302, and 0.183, respectively. The unweighted pair-group method with arithmetic means analysis based on ISSR-SRAP marker data revealed that the genetic similarity coefficient between the tested strains was 0.73-0.97, and the strains could be divided into five groups at 0.742, which had a certain correlation with regional distribution. The results of PCOA and population structure analysis based on ISSR-SRAP data also produced similar results. These results demonstrate the genetic diversity and distinctness among wild A. cornea and provide a theoretical reference for the classification, breeding, germplasm innovation, utilization, and variety protection of A. cornea resources.

Application of noninvasive sampling technique in mitochondrial genome intraspecific phylogeny of the endangered butterfly, Teinopalpus aureus (Lepidoptera: Papilionidae).

The butterfly genus of Teinopalpus, endemic to Asia, embodies a distinct species of mountain-dwelling butterflies with specific habitat requirements. These species are rare in the wild and hold high conservation and research value. Similar to other protected species, the genetic analysis of the rare Teinopalpus aureus poses challenges due to the complexity of sampling. In this study, we successfully extracted DNA and amplified mitochondrial genomic DNA from various noninvasive sources such as larval feces, larval exuviae, larval head capsules, pupal exuviaes, and filamentous gland secretions, all integral parts of butterfly metamorphosis. This was conducted as part of a research initiative focused on the artificial conservation of T. aureus population in Jinggang Shan Nature Reserve. Our findings illustrated the successful extraction of DNA from multiple noninvasive sources, achieved through modified DNA extraction methodologies. Although the DNA concentration obtained from noninvasive samples was lower than that from muscle tissues of newly dead larvae during rearing, all samples met the requirements for PCR amplification and sequencing, yielding complete circular sequences. These sequences are pivotal for both interspecific and intraspecific genetic relationship analysis. Our methods can be extended to other insects, especially scarce species.

Population structure and genetic diversity in Eucalyptus pellita based on SNP markers.

Eucalyptus pellita has the characteristics of rapid growth and high resistance. However, there is little research on molecular breeding of E. pellita, which is essential to shortening breeding life and selecting quality varieties. Therefore, a crucial step before selective breeding can be carried out to increase the wood quality of E. pellita is identifying genetic diversity and population structure using single nucleotide polymorphism (SNP) markers. In this study, the genetic diversity of 1st generation 196 E. pellita families from 23 geographically defined was assessed using 1,677,732 SNP markers identified by whole genome resequencing. SNP annotation showed that the ratio of non-synonymous to synonymous coding mutations was 0.83. Principal component analysis (PCA), phylogenetic tree, and population structure analysis permitted the families to be categorized into three groups, one of which (G2) contains most of the Indonesian (IDN) and Papua New Guinea (PNG) families. Genetic relationship analysis showed that IDN was closely related to PNG. Genetic diversity analysis showed that He, PIC, I, and H mean values were 0.2502, 0.2027, 0.3815, and 0.2680, respectively. PCA analysis classified various provenances in QLD into two categories (G1 and G3). The genetic diversity of G3 was higher than that of G2. The results of genetic differentiation (Fst) showed that PNG region was divided into two groups (PNG1 and PNG2), the Fst (0.172) between QLD and PNG2 region was higher than QLD and PNG1, and the Fst (0.024) between IDN and PNG1 is smaller than IDN and PNG2. A Mantel test revealed a positive correlation between the genetic and geographic distance of E. pellita. This study has a certain reference value for genetic identification, germplasm preservation, and breeding of E. pellita. Also, it provides a basis for subsequent association analysis to explore excellent alleles and introduction.

Evaluation of Molecular Markers and Morphology In Identification of Local Porang Strain in Karawang District

Porang plant tubers have the potential to have high economic value, because they contain glucomannan which is good for health and can be processed into a food source to replace carbohydrates. The aim of the study was to identify Karawang Local Porang strains using molecular markers and morphological characters as an effort to conserve and utilize Karawang's local biological resources. Exploration of Local Porang Karawang was carried out at the foot of Mount Sanggabuana which is the habitat of Porang in Karawang district. Molecular identification was carried out at BBPP Biotechnology and Agricultural Genetic Resources with comparisons of Porang Sidrat., Madiun 1 and SS1 Bulukumba varieties. Morphological identification was carried out at the Basic Laboratory of the Faculty of Agriculture, Winaya Mukti University. Based on the results of the DNA amplification of the Porang samples using four RAPD primers, it was found that the three primers showed differences in banding patterns between the Porang Karawang sample and the three Porang varieties for comparison (Porang Madiun 1 Sidrap and SS1 Bulukumba). This shows that there is genetic variation between Porang from Karawang and three other Porang. The results of genetic relationship analysis using four RAPD primers showed that the Porang Karawang sample was different from the Porang samples from the other two areas. The morphological identification results showed differences in characteristics with the comparison. The Karawang Local Porang variety has high quality as indicated by high glucomannan levels of 79.80%.

Tolerance evaluation and genetic relationship analysis among some economically important chestnut cultivars in Türkiye using drought-associated SSR and EST-SSR markers.

The aim of this study was to evaluate drought tolerance and genetic relationships among some important chestnut cultivars for Türkiye by using drought-related genomic simple sequence repeat (SSR) markers and genic expressed sequence tag-simple sequence repeat (EST-SSR) markers. Using five SSR markers, the average number of alleles (avNa), mean heterozygosity (Havp) and polymorphism information content (PIC) were determined to be 9.22, 0.395 and 0.375, respectively. In addition, using eight EST-SSR markers, the values of avNa, Havp and PIC were determined to be 7.75, 0.309 and 0.262, respectively. All microsatellite markers used in this study showed 100% polymorphism among chestnut cultivars. In UPGMA dendrograms obtained with both SSR and EST-SSR markers, the Erfelek and Hacıömer chestnut cultivars were determined to be the most similar cultivars. Some assessments are discussed regarding drought tolerance for specific alleles obtained from the EST-SSR markers GOT045, GOT021, GOT004, FIR094 and VIT033 in chestnut cultivars. Some preliminary results regarding drought tolerance in chestnut cultivars were obtained in our study with the help of these markers. Our study also characterized the genetic relationships among chestnut cultivars of great importance using drought-related character-specific markers.

Utilizing ISSRseq genotyping to assist growth selection in tomato grouper (Cephalopholis sonnerati) without broodstock information

AbstractGrowth selection in fish is essential for aquaculture; however, long generation times and artificial breeding limitations present challenges for breeding endeavors. The tomato grouper (Cephalopholis sonnerati) is an emerging aquaculture species with a generation cycle of at least 5 to 10 years. Mixed culture of broodstocks and natural mating are commonly employed in hatcheries. To expedite the selection process for tomato grouper, we utilized ISSRseq technology for assisted future growth selection. After 6 months of rearing, we selected 48 individuals, including 24 fast‐growing and 24 slow‐growing individuals (representing the top and bottom 10% of samples). These samples produced 932 SNPs. Although specific broodstock pairing information is unavailable, our results suggest that these fry likely originated from multiple broodstock exhibiting considerable diversity. Further analysis of genetic relationships among individuals revealed three main clades. One clade contained a higher proportion of faster‐growing individuals (80%), while another featured a lower proportion of rapidly growing individuals (28.6%). Through the relatedness network and further exclusion of individuals, the faster‐growth clade comprised 92.3% of fast‐growing individuals. The faster‐growth clade is appropriate for further development into a high‐growth strain. Our findings demonstrate that molecular markers can advance population selective breeding to family selection in aquaculture breeding research.

Development of molecular assays for the analysis of genetic relationships of Mycoplasma iowae

Mycoplasma iowae is a worldwide spread and economically important avian pathogen that mostly infects turkeys. Currently, multi-locus sequence typing (MLST) serves as the gold standard method for strain identification in M. iowae. However, additional robust genotyping methods are required to effectively monitor M. iowae infections and conduct epidemiological investigations. The first aim of this study was to develop genotyping assays with high resolution, that specifically target M. iowae, namely a multiple-locus variable number of tandem-repeats analysis (MLVA) and a core genome multi-locus sequence typing (cgMLST) schema. The second aim was the determination of relationships among a diverse selection of M. iowae strains and clinical isolates with a previous and the newly developed assays. The MLVA was designed based on the analyses of tandem-repeat (TR) regions in the six serotype reference strains (I, J, K, N, Q and R). The cgMLST schema was developed based on the coding sequences (CDSs) common in 95% of the examined 99 isolates. The samples were submitted for a previously published MLST assay for comparison with the developed methods. Out of 94 TR regions identified, 17 alleles were selected for further evaluation by PCR. Finally, seven alleles were chosen to establish the MLVA assay. Additionally, whole genome sequence analyses identified a total of 676 CDSs shared by 95% of the isolates, all of which were included into the developed cgMLST schema. The MLVA discriminated 19 distinct genotypes (GT), while with the cgMLST assay 79 sequence types (ST) could be determined with Simpson’s diversity indices of 0.810 (MLVA) and 0.989 (cgMLST). The applied assays consistently identified the same main clusters among the diverse selection of isolates, thereby demonstrating their suitability for various genetic analyses and their ability to yield congruent results.

Genetic evidence for variability in the social mating system of the Midday Gerbil (Meriones meridianus)

Abstract Social mating systems (e.g., monogamy, polygamy, or polyandry) are relatively stable behavioral strategies developed by environmental in animals, but the genetic imprint of a particular mating system is often incongruent with the social mating system due to extrapair matings. However, the genetics of mating systems remain little understood in rodents. In this study, we investigated the genetic signature of the mating system of 141 (63 females, 78 males) field-captured midday gerbils (Meriones meridianus)—a rodent species commonly found in the Minqin Desert in China—through microsatellite site analyses of genetic structure and relatedness. Seven pairs of highly polymorphic microsatellite loci were selected and were highly polymorphic, with the combined exclusion probability greater than 0.99. The parent pair paternity test by Cervus 3.0 software show that 11 mother–offspring and nine father–offspring relationships were identified in 2018, involving 26 individuals from 10 families. Similarly, 19 mother–offspring and 19 father–offspring relationships were identified in 2019, involving 48 individuals from 18 families. All three types of genetic mating structure were identified—monogamy (19 families), polyandry (4 families), and polygyny (5 families), providing evidence that the genetics underlying mating systems in this species are variable, can be incongruent with behavioral evidence for social mating systems, and could vary based on environmental cues, including degree of perceived or actual predation.

Analysis of genetic diversity and relatedness among cultivated and wild mulberry cultivars/accessions using RAPD markers

Analysis of genetic diversity and relatedness among cultivated and wild mulberry cultivars/accessions using RAPD markers

Comprehensive agrobiological assessment and analysis of genetic relationships of promising walnut varieties of the Nikitsky Botanical Gardens.

Walnut is an important horticultural crop, the production of which ranks second among all nut crops. Despite the significant demand in the domestic market in Russia, the industrial production of walnut fruits in Russia is currently underdeveloped. At the same time, there is a need to update the assortment with new highly productive varieties adapted to local agro-climatic conditions and having high quality nuts that are competitive at the world level. An important issue for the successful implementation of breeding programs is a comprehensive study of the gene pool. In this regard, within the framework of the study, the task was to evaluate promising varieties from the collection of the walnut gene pool of the Nikitsky Botanical Gardens and analyze genetic relationships based on microsatellite genotyping. On the basis of the performed phenotypic assessment, the study sample, which included 31 varieties, was divided into several groups according to the main phenotypic traits, such as frost and drought resistance, the start of the growing season, the ripening period, the weight and type of flowering, the weight of the fruit, and the thickness of the endocarp. Varieties with economically valuable traits that can be recommended as promising as initial parental forms in breeding work for resistance to abiotic stress factors have been identified, as well as varieties with increased productivity and large fruit sizes. Based on the analysis of eight SSR markers (WGA001, WGA376, WGA069, WGA276, WGA009, WGA202, WGA089 and WGA054), an analysis of the level of genetic diversity was performed and genetic relationships were established in the studied sample of varieties. Six (for WGA089) to eleven (for WGA276) alleles per locus have been identified. A total of 70 alleles were identified for the eight DNA markers used, with an average value of 8.75. Analysis of SSR genotyping data using Bayesian analysis established the presence of two main groups of genotypes. Taking into account the fact that all the studied varieties are selections from local seed populations in different regions of the Crimean Peninsula, the revealed level of polymorphism may indirectly reflect the level of genetic diversity of the local walnut populations. Furthermore, the presence of two genetically distant groups indicates the presence of two independently formed pools of the autochthonous gene pool of the species Juglans regia L. on the Crimean Peninsula.

English

Genetic integrity of commercially important fish species is being compromised due to ongoing anthropogenic interventions. Hitherto, there are limited number of studies addressing the questions related to population structure of dwindling fish populations. Studies were undertaken to assess the genetic status of Bagarius bagarius populations from Indus River System by using five microsatellite DNA markers. DNA was extracted by PCI method and genotypic data was generated by PCR amplification of targeted loci. Results showed low-to-moderate level of genetic diversity in terms of number of alleles (Na), allelic richness (Ar), effective number of alleles (Nae) and heterozygosity (Ho and He). The observed heterozygosity (Ho) declined in comparison to the expected heterozygosity (He) in the wild stocks, with mean values ranging from 0.667 to 0.718 and 0.786 to 0.853, respectively. Significant deviation from H-W test was observed in 6 out of 25 tests. The population differentiation (FST) estimates were low (0.0013 to 0.0367) and insignificant. AMOVA showed that 62.38% genetic variation existed within individuals while 4.93% between populations. All of the populations were divided into two clusters by the UPGMA dendrogram constructed for genetic relatedness analysis. The study will be helpful in understanding the impact of genetic integrity on fish populations and, for sustainable management of fish genetic resources