Molecular Diversity Studies Research Articles

Molecular fingerprinting of highly resistant maize lines to turcicum leaf blight

AbstractThe present study generates information related to the molecular divergence between turcicum leaf blight (TLB)-resistant and -susceptible lines. During molecular diversity studies, a total of 212 alleles were detected at 75 marker loci and ranged from two to five with an average of 2.83 alleles per locus. A direct correlation for the number of alleles and polymorphism information content (PIC) values was ascertained. For instance, marker phi123 produced high number of alleles (5) with PIC values of 0.77. Using the DARwin 6.0 programme, the UPGMA dendrogram grouped 40 maize inbreds into two distinct clusters, cluster-I (36 inbreds) and cluster-II (4 inbreds). Cluster-I contained two subclusters; the first subcluster contained 28 inbreds and the second subcluster contained eight inbreds whereas cluster-II contained four inbreds. This major cluster-II was further classified into two subclusters which contained two inbreds each. Most of the inbred lines except V-25 from cluster-II were highly resistant to TLB disease. These inbred lines can be used in crossing programmes to develop TLB-resistant hybrids by using divergent parents. In this study, allelic diversity and PIC values indicated a good efficiency of markers for studying the polymorphism level available in studied inbred lines. High level of diversity among the inbreds detected with simple sequence repeat markers indicated their suitability for the further breeding programme.

Advances in Physalis molecular research: applications in authentication, genetic diversity, phylogenetics, functional genes, and omics.

The plants of the genus Physalis L. have been extensively utilized in traditional and indigenous Chinese medicinal practices for treating a variety of ailments, including dermatitis, malaria, asthma, hepatitis, and liver disorders. The present review aims to achieve a comprehensive and up-to-date investigation of the genus Physalis, a new model crop, to understand plant diversity and fruit development. Several chloroplast DNA-, nuclear ribosomal DNA-, and genomic DNA-based markers, such as psbA-trnH, internal-transcribed spacer (ITS), simple sequence repeat (SSR), random amplified microsatellites (RAMS), sequence-characterized amplified region (SCAR), and single nucleotide polymorphism (SNP), were developed for molecular identification, genetic diversity, and phylogenetic studies of Physalis species. A large number of functional genes involved in inflated calyx syndrome development (AP2-L, MPF2, MPF3, and MAGO), organ growth (AG1, AG2, POS1, and CNR1), and active ingredient metabolism (24ISO, DHCRT, P450-CPL, SR, DUF538, TAS14, and 3β-HSB) were identified contributing to the breeding of novel Physalis varieties. Various omic studies revealed and functionally identified a series of reproductive organ development-related factors, environmental stress-responsive genes, and active component biosynthesis-related enzymes. The chromosome-level genomes of Physalis floridana Rydb., Physalis grisea (Waterf.) M. Martínez, and Physalis pruinosa L. have been recently published providing a valuable resource for genome editing in Physalis crops. Our review summarizes the recent progress in genetic diversity, molecular identification, phylogenetics, functional genes, and the application of omics in the genus Physalis and accelerates efficient utilization of this traditional herb.

Stable nuclear transformation methods for Euglena gracilis and its application to a related Euglenida

Euglenida is a taxonomic group of single-celled flagellates that have a variety of nutrient uptake strategies, making this an excellent model for studying the evolutionary acquisition of secondary chloroplasts. Among Euglenida, Euglena gracilis is the most extensively studied at the biochemical and molecular levels. However, the lack of a widely adopted method of nuclear genome transformation has hindered genetic studies in this organism. Herein, we present a novel nuclear transformation electroporation method that utilizes the 5′ adjacent region sequences of endogenous genes in E. gracilis. We used a NanoLuc reporter to evaluate promoter activity to identify four endogenous promoter candidates with superior luciferase transcriptional activity compared with the activity of the commonly used CaMV 35S promoter in E. gracilis nuclear transformation methods. We used G418 selection to obtain stable E. gracilis transformants harboring the transgene in their genomic DNA. Furthermore, we extended the applicability of our method to Rapaza viridis, a kleptoplastic species in Euglenida. Introduction of the DNA constructs developed for E. gracilis into R. viridis via electroporation generated stable G418-resistant strains exhibiting robust luciferase activity. The introduced promoter sequences functioned effectively, and accurate 5′ end modifications of mRNA were observed in both E. gracilis and R. viridis transformants. These findings demonstrate the broad applicability of our nuclear transformation method across multiple Euglenida species, facilitating molecular biology and genetic diversity studies in this taxonomic group.

Genetic diversity evaluation of core collection gene bank using simple sequence repeat marker of Acorus calamus L.: An important aromatic species

Acorus calamus L. is an important medicinal and aromatic plant having economic and medicinal properties. In the present research, molecular diversity analysis was performed using 138 Acorus calamus accessions obtained from the varied regions of Northeast India. All the collected germplasm was maintained at the Council of Scientific and Industrial Research-North East Institute of Science and Technology (CSIR-NEIST) experimental farm, Jorhat, India. A molecular diversity study was conducted by employing 30 primers screened from 55 simple sequence repeat (SSR) primers based on their polymorphic nature. An average of 99.58% polymorphism was exhibited with a total of 186 polymorphic alleles shown by the selected SSR primers. To estimate the variations among A. calamus accessions, an analysis of molecular variance (AMOVA) was also performed. The genetic diversity among the population was found to be 28% and genetic variations of 72% were observed within the population. Genetic variations within and among populations were found significant with P value of 0.001. The analysis of population-based genetic diversity parameters revealed an average value of 1.84 for the observed number of alleles (Na), 1.48 for an effective number of alleles (Ne), 0.28 for Nei’s genetic diversity index (h), and 0.42 for Shannon's information index in four grouped populations. All the 138 accessions of A. calamus were subdivided into three clusters of dendrogram based on unweighted pair group method with arithmetic mean (UPGMA) analysis. Principal component analysis (PCoA) was further performed and a biplot was constructed for the validation and confirmation of the clusters. Moreover, three genetically diverse populations were also detected by the use of structure harvester software. Until now, there are no such reports on the analysis of the genetic diversity of this industrially important crop using SSR markers. So, it can be considered as the first report on the molecular diversity of A. calamus which will be helpful for the crop improvement, conservation, and identification of the elite genotypes.

The perspective of fish venom: An overview of the physiology, evolution, molecular and genetics

Fish venom has several biological activities, including enzyme activity, cytotoxicity, neurotoxicity, muscular toxicity, haemolytic, and cardiotoxicity, when they enter other species or a human being, they disrupt the physiological systems. Transcriptomic analysis of the fish venom glands revealed a large number of proteins relevant to the pharmacological activity even though they are not well-studied. The limitations in studying fish venoms also have an impact on their molecular characterization. This is partly because of the nature of fish venoms, as they are extremely unstable at normal ambient temperatures making them difficult to study. Venomous fish inhabit both marine and freshwater environments, they have specialized venom-delivery apparatuses. Venom delivery systems have evolved in a various animal species, originally for different purposes including defense, competition, as well as predation. In coastal areas, fish stings are a major problem because they have a serious toxic effect on fishermen, local communities, and visitors. In this study, we have discussed the general perspective of fish venom from marine and freshwater species in different aspects basically in their molecular evolution, physiology, diversity, transcriptome, and proteomic studies. We expect that this paper will provide readers with a unique perspective on understanding the current status of fish venom research as well as working for future studies. Therefore, the gap of knowledge acquired from this study will play as a baseline for researchers discovering new studies and using fish venom in a broader range of biomedical applications, and their biological information that can be used to develop drugs for pharmaceutical uses.

Molecular Markers in Plant Breeding

Molecular markers are an important tool for plant breeding. Since the 1980s, in response to the technology development, molecular marker approaches have been further diversified. The establishment of new-generation sequencing and high-throughput plant phenotyping has greatly decreased the time to genotype large numbers of individuals. For breeders who are not very familiar with molecular techniques and want to catch up with the advances in the field, this review offers basic knowledge. Each molecular marker technology has specific advantages as well as limitations. Molecular marker types, diversity studies, QTL mapping, associative mapping, marker-assisted backcrossing and genomic selection are explored. Marker application in plant breeding is also described. In the genome, molecular markers can detect the genetic architecture of a trait, but also identify candidate genes with an important role in plant breeding programs.

Infraspecific Anatomical Study of Salvia limbata C. A. Mey. (Lamiaceae) in Iran

Salvia limbata is a medicinal plant of the Lamiaceae family that is naturally distributed in various regions of Iran and neighboring countries. In the current evaluation, the leaf blade and petiole anatomical variables were examined in eight Iranian S. limbata populations to explore their taxonomic significance and interpopulation variations. The evaluated populations were harvested from three subprovinces of the Irano-Turanian province. The plant samples were fixed in formaldehyde 90%, ethanol 5%, acetic acid 5% solution, and the hand cross sections of the blade and petiole were double stained with carmine and methylene blue. Data were analyzed using PAST ver. 2.1 and findings revealed that all qualitative variables were invariable between populations, except for the shape of the leaf blade and the epidermal cells of the petiole. Most quantitative traits varied among the considered populations by principal component analysis (PCA) and divided the investigated characteristics into seven components, where two first components had more than 80% of the total variation. In PCA loading, most of the characteristics assessed were negatively correlated. According to UPGMA dendrogram and PCA plot, the populations were clustered into three groups. The PCA biplot revealed the distinct characteristic(s) for each classified group. The clustering patterns of these populations were not in agreement with the geographical distance and phytogeographic similarity between the populations. Several anatomical characteristics were found similar to those recorded in some Lamiaceae genera and lacked taxonomic value, whereas others had taxonomic importance at the infraspecific level. According to a phytogeographic survey and a previous study of molecular genetic diversity, it can be suggested that genetic background can create enough anatomical adaption in populations of S. limbata to establish itself in a wide range of habitats. Meanwhile, the microhabitat has a powerful influence on the anatomical structure.

A Bibliometric Analysis of Indonesia Biodiversity Identification through DNA Barcoding Research from 2004-2021

Abstract Indonesia is well-known for having a vast and rich endowment of unique and genetically diverse biodiversity resources. Currently, initiatives are taking place around the world to generate DNA barcode libraries to make these data available to better understand biodiversity. The objectives of this study are to document DNA barcode research trends and detect the extent to which its application has evolved in Indonesia. The analysis was investigated using a compilation of 446 published papers, obtained from Harzing's Publish or Perish 8. The number of DNA barcode publication records has increased by a geometric average of 15.4/year. The number of studies involving molecular identification (30.1%), species and genetic diversity (10%), and evolutionary or phylogenetic studies (10%) appears to have driven much of the publication activity. The top three taxa studied include fishes (32.7%), plants (24.8%), and invertebrates (12.5%; except insects). We discovered that using a single molecular marker is still dominant (62.8%). We conclude that the practices of DNA barcoding data are likely to become a valuable resource in many sectors and focuses. However, the number of Indonesian DNA barcode records in public databases is relatively lower than in other mega biodiversity countries. The establishment of DNA barcoding initiatives and a national DNA barcode reference library in Indonesia would promote DNA barcoding applications to help conserve Indonesia biodiversity. Keywords: Biodiversity, DNA barcode, Indonesia, Research trends

Conservation strategies for endemic Dendrocalamus manipureanus: A study on genetic diversity and population structure based on molecular and phytochemical markers

Genetic diversity and population structure studies were conducted for the first time on endemic Dendrocalamus manipureanus of Manipur, northeast India, using molecular and phytochemical markers. 15 inter simple sequence repeats (ISSR) and 11 start codon targeted (SCoT) primers produced 136 and 91 polymorphic bands, respectively, generating high polymorphism. 10 primers of inter primer binding site (iPBS) markers gave 94 polymorphic bands producing 100% polymorphism. The Mantel test showed no significant correlation between markers indicating the necessity of employing a combination of multiple markers in diversity assessment. Combined marker analysis showed high genetic differentiation among populations (Gst = 0.684) due to low gene flow (Nm = 0.230). Analysis of molecular variance (AMOVA) also disclosed high genetic variation (67%) among the population and low diversity (33%) within the populations. BARRIER analysis identified 9 putative genetic barriers separating D. manipureanus populations, affirming the possible hindrance to gene flow. Neighbor-joining dendrogram and principal coordinate analysis (PCoA) revealed the absence of mixed clustering patterns. Bayesian model STRUCTURE analysis grouped D. manipureanus populations into 7 genetic clusters (K = 7) with less admixture. GENELAND further assigned the bamboo genotypes into 9 different genetic pools, confirming a high level of genetic isolation among the populations. The phytochemical examination further validated the molecular diversity studies with a similar bamboo diversity profile generation. The positive correlation between the genetic and phytochemical distance (r = 0.62, P = 0.01) confirmed that the phytochemical investigation could substantiate molecular diversity studies. The measures recommended from the crucial genetic findings might be utilized for genetic improvement and management of the endemic bamboo in the region.

Edible fungi for local and sustainable development in the Patagonian Andes forests of Argentina: A review

Wild fungi are one of the most characteristic and diverse non-wood forest products from native and planted forest environments and grasslands in the Patagonian Andes. Through the technological and scientific platform “Patagonia Fungi, trails and tastes®”, we work to promote mycotourism and mycogastronomy as sustainable identity and inclusive economic and educational activities that promote local development, taking advantage of the outstanding regional tourist profile. We also work on the development of functional foods and promote the cultivation of edible and medicinal fungi. The main objectives of this research were to define novel edible species and evaluate them for sustainable uses, including: environmental characterizations of their fruiting niches and ‘mycosilvicultural’ managements to increase their productivity; documentation and analysis of the ancestral uses and their processes of change; determination of the nutritional and nutraceutical profiles; studies of molecular genetic diversity of various genera; protocols for the domestication of wild species; evaluation and selection of lignocellulosic substrates for cultivation from available residues in Patagonian Andes; economic aspects related to the marketing and use in local gastronomy; evaluation of postharvest preservation techniques. Most relevant actions include the design and implementation of mycotourism trails, the promotion of an identity mycogastronomy; the inter-institutional management of protocols for sustainable harvesting and food safety practices; the incorporation of 21 new species in the Argentinean Food Code. We also work for food sovereignty through a spawn production laboratory fostering edible and medicinal fungi cultivation through courses and assistance to producers from family to productive scales.

Molecular genetic diversity in dual purpose and land races of pigeonpea (Cajanus cajan (L.) Millsp.)

Molecular genetic diversity was assessed among 32 dual purpose and land races of pigeonpea using 20 pigeonpea specific SSR markers. Among 20 markers, 15 markers revealed polymorphism, while five markers exhibited a monomorphic banding pattern. The polymorphic markers produced a total of 43 alleles with an average of 2.15 alleles per marker. The markers CcM 0008 and CcM 1026 produced the highest number of alleles (4). The Polymorphic Information Content (PIC) value of the markers ranged from 0.06 (PGM 16) to 0.64 (CcM 0008) with an average of 0.19. A dendrogram constructed using UPGMA distinguished 32 genotypes into 10 clusters. Cluster I was the largest with 15 genotypes followed by cluster V with five genotypes. The Neighbour- joining tree produced based on the weighted average for dissimilarity matrix grouped the 32 genotypes into eight groups. Among them group II was the largest comprising of 10 genotypes. Based on the molecular genetic diversity study using SSR markers, the genotypes Kunnathur local, CRG 13-01, BSR 1 and Pillayakothur local were found diverse among the genotypes and had good grain and vegetable pigeonpea traits could be used in the breeding programme. The results indicated that SSR markers provide a more definitive separation of clusters indicating a higher level of efficiency for determining the relationship among pigeonpea genotypes. Keywords:  Pigeonpea, Dual purpose, Land races, Genetic diversity   &nbsp

Molecular Characterization and Validation of Micro-Satellite Markers Linked to Powdery Mildew Disease Resistance in Mini Core Germplasm of Urdbean [Vigna mungo (L.) Hepper

Twenty-nine Urdbean [Vigna mungo (L.) Hepper] genotypes, including four check varieties 'Prasad,' 'Ujala,' 'PU-31' and 'OBG-31' were evaluated in the experimental farm of Odisha University of Agriculture and Technology, Bhubaneswar, India, for two seasons to assess these genotypes against powdery mildew disease incidence and to estimate the extent of genetic divergence and character association employing molecular markers. For molecular diversity studies five molecular markers i.e., MB-SSR238, VrCsSTS1, CEDG191, VrCsSSR1, CEDG166 were evaluated on the Urdbean genotypes. The results showed the association of VrCsSTS1 marker with the powdery mildew resistance gene in different genetic backgrounds. The genotypes 'OBG-31', 'Ujala,' 'Prasad,' and 'Nayagarh-I local' were resistant to powdery mildew disease, which can be further used for breeding programs.

Elucidating genetic diversity and association mapping to identify SSR markers linked to 100 seed weight in chickpea (Cicer arietinum L.)

Chickpea, a cool-season grain legume enriched with high nutritive value is grown globally over 90 countries. Seed weight trait is one of the important quality parameters for fetching premium market price. Thus, improving seed traits, including high 100-seed weight (SW) is one of the major targets of chickpea breeding. A study of genetic variability, molecular diversity and marker-trait association (MTA) analysis for 100 SW was performed in a panel of 96 chickpea genotypes consisting of crop wild relatives, landraces, advanced breeding lines and released varieties. A wide range of genetic variability and high heritability for the studied trait indicated the great scope of improving this trait. Simple sequence repeat marker-based genetic diversity analysis grouped all the genotypes into two groups. This result was consistent with the result obtained from factorial and population structure analysis. To delineate the significant marker-trait association for 100 SW, association analysis was performed in the given panel of chickpea genotypes. The mixed linear model (MLM) was employed for detecting significant MTAs for 100 SW. Following MLM analysis, a total of seven significant MTAs was detected in the year 2016-17. While in the year 2017-18, MLM analysis showed three significant MTAs for 100 SW. Three markers TAA60, CakTpSSR02719, H1B04 markers exhibited significant MTA for both the years consistently. Thus, these genomic regions could be fine mapped in future for improving 100 SW in chickpea.

Population Structure Analysis and Association Mapping for Turcicum Leaf Blight Resistance in Tropical Maize Using SSR Markers.

Maize is an important cereal crop in the world for feed, food, fodder, and raw materials of industries. Turcicum leaf blight (TLB) is a major foliar disease that can cause more than 50% yield losses in maize. Considering this, the molecular diversity, population structure, and genome-wide association study (GWAS) for TLB resistance were studied in 288 diverse inbred lines genotyped using 89 polymorphic simple sequence repeats (SSR) markers. These lines werescreened for TLB disease at two hot-spot locations under artificially inoculated conditions. The average percent disease incidence (PDI) calculated for each genotype ranged from 17 (UMI 1201) to 78% (IML 12-22) with an overall mean of 40%. The numbers of alleles detected at a locus ranged from twoto nine, with a total of 388 alleles. The polymorphic information content (PIC) of each marker ranged between 0.04 and 0.86. Out of 89 markers, 47 markers were highly polymorphic (PIC ≥ 0.60). This indicated that the SSR markers used were very informative and suitable for genetic diversity, population structure, and marker-trait association studies.The overall observed homozygosity for highly polymorphic markers was 0.98, which indicated that lines used were genetically pure. Neighbor-joining clustering, factorial analysis, and population structure studies clustered the 288 lines into 3–5 groups. The patterns of grouping were in agreement with the origin and pedigree records of the genotypesto a greater extent.A total of 94.10% lines were successfully assigned to one or another group at a membership probability of ≥0.60. An analysis of molecular variance (AMOVA) revealed highly significant differences among populations and within individuals. Linkage disequilibrium for r2 and D′ between loci ranged from 0 to 0.77 and 0 to 1, respectively. A marker trait association analysis carried out using a general linear model (GLM) and mixed linear model (MLM), identified 15 SSRs markers significantly associated with TLB resistance.These 15 markers were located on almost all chromosomes (Chr) except 7, 8, and 9. The phenotypic variation explained by these loci ranged from 6% (umc1367) to 26% (nc130, phi085). Maximum 7 associated markers were located together on Chr 2 and 5. The selected regions identified on Chr 2 and 5 corroborated the previous studies carried out in the Indian maize germplasm. Further, 11 candidate genes were identified to be associated with significant markers. The identified sources for TLB resistance and associated markers may be utilized in molecular breeding for the development of suitable genotypes.

DNA barcoding technique: application and perspectives in beetles identification

The DNA barcoding technique promotes the study of molecular diversity as a tool for species identification based on DNA sequences. This paper reflects the efficiency of the DNA barcoding technique for species identification based on tenebrionoid beetles. As a result, the DNA barcode sequences were obtained for eight species of beetles from the superfamily Tenebrionoidea found on the territory of the Republic of Moldova, also contributing with new nucleotide sequences to the international DNA barcode libraries. 56 references, 3 figures, 3 tables

Genetic diversity and phylogeny analysis of 3-hydroxy 3-methylglutaryl-CoA reductase gene (SmHMGR) in Danshen (Salvia miltiorrhiza Bunge)

AbstractHMGR, 3-hydroxy-3-methylglutaryl-CoA reductase, is a major rate-limiting enzyme in mevalonate (MVA) pathway for isoprenoids and subsequent tanshinone biosynthesis in the Chinese traditional bulk herbal medicine Danshen, Salvia miltiorrhiza, mainly for cardiovascular disorders. In this paper, the genomic SmHMGR genes of 38 cultivated populations of S. miltiorrhiza collected in China were for the first time sequenced to reveal the genetic diversity and phylogeny. The SmHMGR gene was shown to be intron-free, 1650~1659 bp in complete CDS with the majority being 1656 bp, and two unique populations (W-FJLY-V-1 and W-SCHY-W-1) being 1659 and 1650 bp respectively. A total of 103 SNP variation sites were detected with a variation rate of 6.22%, most of which occurred in S. miltiorrhiza f. alba population W-SCHY-W-1; a total of 25 amino acid variation sites were found, of which 19 was in W-SCHY-W-1. The same four populations, W-SCHY-W-1, V-HBAG-V-1, V-JLCC-V-1 and S-NM-V-1 could be discriminated from the remaining 34 by both the SNP fingerprints and the deduced amino acid variation sites. Other or composite DNA markers are needed for better identification. The SmHMGR gene of white flower S. miltiorrhiza f. alba population W-SCHY-W-1 is especially rich in variations and worthy of further studies. Phylogenetic trees based on both the gene and the deduced amino acid sequences showed a very similar two-clade topological structure. This research enriched the content and the genetic means for the molecular identification, genetic diversity and phylogenetic studies of the cultivated S. miltiorrhiza populations, and laid a solid foundation for further related and in-depth investigations.

Molecular diversity and nutriment studies of common bean (

The diverse microclimatic belts of the Western Himalayan region of India are considered hot spots for genetic diversity of common bean (Phaseolus vulgaris L.). Western Himalayan beans are known for various agronomically superior/important traits including unique aroma, taste and cooking quality. In the present study, 25 unlinked genomic simple sequence repeat (SSR) markers distributed across the common bean genome were used to assess the genetic/allelic diversity among and within populations belonging to the Jammu and Kashmir regions of the Western Himalayas. These two regions are considered most important hot-spots for common bean diversity in western-Himalayas. The analysis of genotypic data of SSR markers revealed a total of 263 alleles with an average of 10.52 alleles per locus. The genetic diversity analysis revealed higher variability in bean landraces belonging to Jammu region (He = 0.73) as compared to genotypes from Kashmir region (He = 0.647) and some exotic genotypes (0.71). The genotypes were also phenotyped for four important nutritional traits and the analysis of trait data revealed that sugar content was highest in common bean genotypes from Jammu region, while protein, starch and phenol content were highest in exotic common bean genotypes. Therefore, the superiority of common bean germplasm from Jammu region may be due to a higher level of allelic diversity, more private alleles and higher sugar content. The diverse genotypes based on genotypic data and trait performance will prove useful in future breeding programs aimed at enhancing nutritional contents of common bean varieties.

Chloroplast Genomes for Five Skeletonema Species: Comparative and Phylogenetic Analysis.

Skeletonema species are cosmopolitan coastal diatoms that exhibit important roles in ecological system. The chloroplast genomes (cpDNAs) have been proven to be important in the study of molecular evolution and genetic diversity. However, cpDNA of only a single Skeletonema species (S. pseudocostatum) has been constructed, hindering in-depth investigation on Skeletonema species. In this study, complete cpDNAs of five Skeletonema species were constructed with cpDNAs of four species S. marinoi, S. tropicum, S. costatum, and S. grevillea constructed for the first time. These cpDNAs had similar sizes and same numbers of genes. These cpDNAs were highly syntenic with no substantial expansions, contractions, or inversions. Interestingly, two copies of petF, which encodes ferredoxin with critical role in iron dependency, were found in all five Skeletonema species, with one copy in the cpDNA and another copy in the nuclear genome of each species. Selection analysis revealed that all PCGs of cpDNAs were undergoing purifying selection. Despite the high conservation of these cpDNAs, nine genomic regions with high sequence divergence were identified, which illustrated substantial variations that could be used as markers for phylogenetic inference and for tracking Skeletonema species in the field. Additionally, the numbers of simple sequence repeats varied among different cpDNAs, which were useful for detecting genetic polymorphisms. The divergence times estimated using PCGs of cpDNAs revealed that most of these species were established within ∼33 Mya, consistent with that estimated using mtDNAs. Overall, the current study deepened our understanding about the molecular evolution of Skeletonema cpDNAs.

English

Sorghum [Sorghum bicolor (L.) Moench], is believed to be originated in Ethiopia and Sudan. Although, many morphological and molecular diversity studies reveal the existence of genetic variations with sorghum populations, their distribution within basic races were not considered. Hence, the present study aimed to analyze the extent and distribution of genetic variation within basic Ethiopian sorghum landraces using SSR markers. A total of 107 landraces obtained from Ethiopian Biodiversity Institute (EBI) representing 12 ecological zones grouped according to their race types based on inflorescence and spiklet on field at their maturity time. Twelve SSR markers revealed a total of 110 alleles with average polymorphic content of 0.76 and the allele frequencies show 42 of them were rare (less than 0.05), 22 ranged from 0.05 to 0.1, while 46 of them were higher than 0.1. Expected and observed heterozygosity were 0.78 and 0.2, respectively. The genetic differentiation between populations were also moderate (FST=0.07 for races and 0.13 for E/zones) indicating continuous exchange of genes among them. Partitioning the total genetic variation also indicated 61.38 and 55.17% of the variations were among individuals within racial and zonal populations, respectively. Neighbor-Joining cluster analysis also indicated four major grouping of the landraces according to their racial groups where majority of race caudatum and durra form separate groups while intermediate durra-bicolor form two separate sub-clusters. Overall locus, the intra-racial population diversity showed the greatest genetic diversity (He=0.77 and 0.75) among race dura-bicolor and caudatum, respectively. Information with sorghum races along their important agronomic traits could be used for conservation and future breeding programs of sorghum.   Key words: Sorghum bicolor, races, genetic diversity, SSR.

Whole-Genome Sequences of SARS-CoV-2 Isolates from the Dominican Republic.

ABSTRACTHere, we report the genome sequences of five severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains that were obtained from symptomatic individuals with travel histories during community surveillance in the Dominican Republic in 2020. These sequences provide a starting point for further genomic studies of gene flow and molecular diversity in the Caribbean nation. Phylogenetic analysis suggests that all genomes correspond to the B.1 variant.