High Polymorphism Research Articles

Identification of candidate genes for LepR1 resistance against Leptosphaeria maculans in Brassica napus.

Utilising resistance (R) genes, such as LepR1, against Leptosphaeria maculans, the causal agent of blackleg in canola (Brassica napus), could help manage the disease in the field and increase crop yield. Here we present a genome wide association study (GWAS) in B. napus to identify LepR1 candidate genes. Disease phenotyping of 104 B. napus genotypes revealed 30 resistant and 74 susceptible lines. Whole genome re-sequencing of these cultivars yielded over 3 million high quality single nucleotide polymorphisms (SNPs). GWAS in mixed linear model (MLM) revealed a total of 2,166 significant SNPs associated with LepR1 resistance. Of these SNPs, 2108 (97%) were found on chromosome A02 of B. napus cv. Darmor bzh v9 with a delineated LepR1_mlm1 QTL at 15.11-26.08 Mb. In LepR1_mlm1, there are 30 resistance gene analogs (RGAs) (13 nucleotide-binding site-leucine rich repeats (NLRs), 12 receptor-like kinases (RLKs), and 5 transmembrane-coiled-coil (TM-CCs)). Sequence analysis of alleles in resistant and susceptible lines was undertaken to identify candidate genes. This research provides insights into blackleg resistance in B. napus and assists identification of the functional LepR1 blackleg resistance gene.

Analysis of genetic diversity and population structure in sweetpotato using SSR markers

Sweetpotato, Ipomoea batatas (L.) Lam., is an important food crop worldwide. Large scale evaluation of sweetpotato germplasm for genetic diversity is necessary to determine the genetic relationships between them and effectively use them in the genetic improvement. In this study, the genetic diversity of 617 sweetpotato accessions, including 376 landraces and 162 bred varieties from China and 79 introduced varieties from 11 other countries, was assessed using 30 simple sequence repeat (SSR) primer pairs with high polymorphism. Based on the population structure analysis, these sweetpotato accessions were divided into three groups, Group 1, Group 2 and Group 3, which included 228, 136 and 253 accessions, respectively. Consistent results were obtained by phylogenic analysis and principal coordinate analysis (PCoA). Of the three groups, Group 2 showed the highest level of genetic diversity and its accessions were mainly distributed in low-latitude regions. The accessions from South China exhibited the highest level of genetic diversity, which supports the hypothesis that Fujian and Guangdong were the first regions where sweetpotato was introduced to China. Analysis of molecular variance (AMOVA) indicated significant genetic differentiations between the different groups, but low levels of genetic differentiation existed between the different origins and accession types. These results provide valuable information for the better utilization of these accessions in sweetpotato breeding.

Defending against SARS-CoV-2: The T cell perspective.

SARS-CoV-2-specific T cell response has been proven essential for viral clearance, COVID-19 outcome and long-term memory. Impaired early T cell-driven immunity leads to a severe form of the disease associated with lymphopenia, hyperinflammation and imbalanced humoral response. Analyses of acute SARS-CoV-2 infection have revealed that mild COVID-19 course is characterized by an early induction of specific T cells within the first 7 days of symptoms, coordinately followed by antibody production for an effective control of viral infection. In contrast, patients who do not develop an early specific cellular response and initiate a humoral immune response with subsequent production of high levels of antibodies, develop severe symptoms. Yet, delayed and persistent bystander CD8+ T cell activation has been also reported in hospitalized patients and could be a driver of lung pathology. Literature supports that long-term maintenance of T cell response appears more stable than antibody titters. Up to date, virus-specific T cell memory has been detected 22 months post-symptom onset, with a predominant IL-2 memory response compared to IFN-γ. Furthermore, T cell responses are conserved against the emerging variants of concern (VoCs) while these variants are mostly able to evade humoral responses. This could be partly explained by the high HLA polymorphism whereby the viral epitope repertoire recognized could differ among individuals, greatly decreasing the likelihood of immune escape. Current COVID-19-vaccination has been shown to elicit Th1-driven spike-specific T cell response, as does natural infection, which provides substantial protection against severe COVID-19 and death. In addition, mucosal vaccination has been reported to induce strong adaptive responses both locally and systemically and to protect against VoCs in animal models. The optimization of vaccine formulations by including a variety of viral regions, innovative adjuvants or diverse administration routes could result in a desirable enhanced cellular response and memory, and help to prevent breakthrough infections. In summary, the increasing evidence highlights the relevance of monitoring SARS-CoV-2-specific cellular immune response, and not only antibody levels, as a correlate for protection after infection and/or vaccination. Moreover, it may help to better identify target populations that could benefit most from booster doses and to personalize vaccination strategies.

Photocatalytic degradation of orange II dye via high pore volume polymorph zirconium-doped titania under visible light irradiation

A series of mixed-phase Zr-doped TiO2 was utilized for the photocatalytic degradation of orange II dye. These materials were synthesized through a sol–gel technique by varying the amounts of zirconium in the photocatalysts. These materials were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray fluorescence (XRF), Raman spectroscopy, thermogravimetry analysis (TGA), and X-ray photoelectron spectroscopy (XPS) among others. XRF and XPS data showed that the elemental composition of the photocatalysts consists of zirconium, titanium, and oxygen. In addition, XRD and Raman spectroscopy confirmed the existence of anatase and rutile phases of TiO2. The TGA analyses showed that the undoped TiO2 was the most stable, with no significant weight loss during the heating range. Furthermore, the materials can effectively degrade orange II dye solution up to 7 cycles through asymmetric cleavage of the azo bond.

Assessment of Genetic Diversity of Local Coffee Populations in Southwestern Saudi Arabia Using SRAP Markers

Coffea arabica, a member of the Rubiaceae family, is the most commercially important species of the genus Coffea. It has been grown on the mountain terraces of southwestern Saudi Arabia for centuries. At present, the species is subject to increased genetic erosion due to the abandonment of many gardens by their owners and the increasingly dry climate. The current study was carried out to determine the genetic diversity of 56 local coffee accessions collected from the southern regions of Saudi Arabia using 30 sequence-related amplified polymorphism (SRAP) markers. Six SRAP markers showed polymorphism among the 56 accessions. A total of 1125 bands, with an average of 187.5, was produced from all six SRAP primers. The polymorphic information content (PIC) ranged from 74.8 to 97.7, with an average of 91.4 for all studied SRAP markers. The high polymorphism percentage seen in this study, along with the high number of alleles produced and the high PIC values of the primers used, demonstrate that the SRAP approach was an effective molecular technique for assessing genetic diversity in the studied populations. The structural analysis showed a sharp peak, with no ambiguity, demonstrating the highest delta K value at K = 3 and K = 6, and the coffee accessions could be grouped into three and six main populations, respectively. The PCoA, cluster analysis, and structural population analysis results suggest considerable genetic diversity among coffee populations growing on the southwestern mountain terraces of Saudi Arabia. The 56 accessions were segregated into five groups, mostly according to geographic distribution. The accessions from the southern districts of Jazan region mostly clustered in groups 2 and 4, while the accessions from the northern districts of Al-Baha and Assir regions formed separate groups. Based on these analyses, accessions KSA1R, KSA6R, KSA21, KSA25, KSA37, KSA38, KSA42, KSA59, KSA60, KSA62, and KSA63 were the most divergent. The genotypes should be conserved for use in coffee-breeding programs to improve the agronomic value of the crop, broaden the genetic base of C. arabica in Saudi Arabia and increase environmental resilience. Additional molecular and functional genomics studies are necessary to further elucidate how this germplasm has evolved and enhance the value of local Arabica coffee diversity in the Kingdom.

Management of genetic erosion: The (successful) case study of the pear (Pyrus communis L.) germplasm of the Lazio region (Italy).

Pyrus communis L. is an important temperate fruit with high nutritional and economic value. Italy, as the largest pear producer in the EU and second in the world, has a particularly rich germplasm characterized by hundreds of local varieties. The Lazio Region was the first Italian region to start programs focused on safeguarding varieties at risk of extinction and has started a massive census of fruit varieties by combining molecular data and productive-territorial information. In this study, 311 pear accessions collected from the five provinces of the Lazio region were genetically characterized by the means of nine simple sequence repeat (SSR) markers, eight of which were recommended by the European Cooperative Programme for Plant Genetic Resources (ECPGR). The SSR analysis revealed 250 unique genotypes and 14 cases of synonymies, namely, accessions with different names but identical molecular profiles (100% genetic similarity). The microsatellite set showed a high polymorphism information content (PIC; mean PIC=0.77) and an exceptionally high discrimination power (DP = 0.99), making it particularly efficient both for the study of genetic diversity and for the prediction of the degree of ploidy. Notably, 20% of the accessions displayed triallelic profiles (i.e., accessions having ≥2 loci with a third allele), while the remaining accessions were diploids. These results were further confirmed by flow cytometry data analysis. Standardization of the molecular analyses at the national and international levels and harmonization of the SSR sets used for germplasm characterization are of paramount importance for producing molecular profiles useful for registration and variety maintenance.

Development and Evaluation of High-Density SNP Arrays for the Eastern Oyster Crassostrea virginica.

The eastern oyster Crassostrea virginica is a major aquaculture species for the USA. The sustainable development of eastern oyster aquaculture depends upon the continued improvement of cultured stocks through advanced breeding technologies. The Eastern Oyster Breeding Consortium (EOBC) was formed to advance the genetics and breeding of the eastern oyster. To facilitate efficient genotyping needed for genomic studies and selection, the consortium developed two single-nucleotide polymorphism (SNP) arrays for the eastern oyster: one screening array with 566K SNPs and one breeders' array with 66K SNPs. The 566K screening array was developed based on whole-genome resequencing data from 292 oysters from Atlantic and Gulf of Mexico populations; it contains 566,262 SNPs including 47K from protein-coding genes with a marker conversion rate of 48.34%. The 66K array was developed using best-performing SNPs from the screening array, which contained 65,893 oyster SNPs including 22,984 genic markers with a calling rate of 99.34%, a concordance rate of 99.81%, and a much-improved marker conversion rate of 92.04%. Null alleles attributable to large indels were found in 13.1% of the SNPs, suggesting that copy number variation is pervasive. Both arrays provided easy identification and separation of selected stocks from wild progenitor populations. The arrays contain 31 mitochondrial SNPs that allowed unambiguous identification of Gulf mitochondrial genotypes in some Atlantic populations. The arrays also contain 756 probes from 13 oyster and human pathogens for possible detection. Our results show that marker conversion rate is low in high polymorphism species and that the two-step process of array development can greatly improve array performance. The two arrays will advance genomic research and accelerate genetic improvement of the eastern oyster by delineating genetic architecture of production traits and enabling genomic selection. The arrays also may be used to monitor pedigree and inbreeding, identify selected stocks and their introgression into wild populations, and assess the success of oyster restoration.

Host-parasite interactions during Plasmodium infection: Implications for immunotherapies.

Malaria is a global infectious disease that remains a leading cause of morbidity and mortality in the developing world. Multiple environmental and host and parasite factors govern the clinical outcomes of malaria. The host immune response against the Plasmodium parasite is heterogenous and stage-specific both in the human host and mosquito vector. The Plasmodium parasite virulence is predominantly associated with its ability to evade the host's immune response. Despite the availability of drug-based therapies, Plasmodium parasites can acquire drug resistance due to high antigenic variations and allelic polymorphisms. The lack of licensed vaccines against Plasmodium infection necessitates the development of effective, safe and successful therapeutics. To design an effective vaccine, it is important to study the immune evasion strategies and stage-specific Plasmodium proteins, which are targets of the host immune response. This review provides an overview of the host immune defense mechanisms and parasite immune evasion strategies during Plasmodium infection. Furthermore, we also summarize and discuss the current progress in various anti-malarial vaccine approaches, along with antibody-based therapy involving monoclonal antibodies, and research advancements in host-directed therapy, which can together open new avenues for developing novel immunotherapies against malaria infection and transmission.

Diversity, classification, and EST‐SSR‐based association analysis of caladium ornamental traits

Caladium (Caladium × Hortulanum Birdsey) is a popular ornamental plant with a wide range of vibrant leaf color among Araceae. Even after years of breeding, creating new caladium leaf color variations is extremely difficult. Molecular marker-assisted selection is an effective approach for accelerating breeding, but few studies on the molecular markers associated with caladium traits have been performed. In the current study, 144 caladium accessions were used to examine 12 phenotypic characteristics. The coefficient of variation for four numerical characters ranged from 23.94% to 43.22%, and the Shannon-Wiener indexes for eight descriptive characters ranged from 0.13 to 1.52. Based on L*, a*, b*, C, h° values determined by a colorimeter and hierarchical cluster analysis, the leaf color can be divided into four groups: pale green, green, light pink, and red. Furthermore, 7708 new SSR loci were identified by transcriptome sequencing, and 26 SSR markers with high polymorphism and reproducibility were screened. Genetic structure, NJ clustering, and PCoA analysis revealed that 144 accessions could be divided into three clusters, with genetic structure being closely related to germplasm origin. An association analysis revealed that the SSR markers 2, 1, 1, 1, 1, and 1 were mainly associated with petiole color, main vein color, blade upperside glossiness, and C, b*, and L* of leaf color (p < 0.01). These findings will serve as a valuable reference for evaluating germplasm resources and caladium molecular marker-assisted breeding.

Genetic diversity and population structure of sorghum [Sorghum bicolor (L.) Moench] genotypes in Ethiopia as revealed by microsatellite markers

In the tropical and semi-arid regions of Africa, sorghum [Sorghum bicolor (L.) Moench] is mainly grown as a major food security crop. Understanding the extent and pattern of genetic variability is a prerequisite criterion for sorghum improvement and conservation. The genetic diversity and population structure of 100 genotypes of sorghum were profiled using 15 microsatellite loci. A total of 108 alleles, with an overall mean of 7.2 alleles per locus, were produced by all of the microsatellite loci used due to their high polymorphism. Polymorphic information content values ranging from 0.68 to 0.89 indicated that all of the loci are effective genetic tools for analysing the genetic structure of sorghum. Different diversity metrics were used to evaluate genetic diversity among populations, and Nei's gene diversity index ranged from 0.74 to 0.81 with an overall mean of 0.78. Poor genetic differentiation (FST: 0.02; p < 0.0001) was found, where 98% of entire variability was accounted by the within populations genetic variability, leaving only 2.32% among populations. The highest genetic differentiation and Nis's genetic distance were observed between the sorghum populations of the Southern Nation and Nationalities Peoples and Dire Dawa regions. Due to increased gene flow (Nm = 10.53), the clustering, principal coordinate analysis and STRUCTURE analysis failed to categorize the populations into genetically different groups corresponding to their geographic sampling areas. In general, it was found that the microsatellite loci were highly informative and therefore valuable genetic tools to unfold the genetic diversity and population structure of Ethiopian sorghum genotypes. Among the five populations studied, sorghum populations from Amhara and Oromia had the highest genetic variation, indicating that the regions could be perhaps hotspots for useful alleles for the development of better-performing genotypes, and also for designing appropriate germplasm management strategies.

Diversity, Ecological Characteristics and Identification of Some Problematic Phytopathogenic Fusarium in Soil: A Review

The genus Fusarium includes many pathogenic species causing a wide range of plant diseases that lead to high economic losses. In this review, we describe how the Fusarium taxonomy has changed with the development of microbiological methods. We specify the ecological traits of this genus and the methods of its identification in soils, particularly the detection of phytopathogenic representatives of Fusarium and the mycotoxins produced by them. The negative effects of soil-borne phytopathogenic Fusarium on agricultural plants and current methods for its control are discussed. Due to the high complexity and polymorphism of Fusarium species, integrated approaches for the risk assessment of Fusarium diseases are necessary.

PNPLA3 GENE POLYMORPHISM AND RED MEAT CONSUMPTION INCREASED FIBROSIS RISK IN NASH BIOPSY-PROVEN PATIENTS UNDER MEDICAL FOLLOW-UP IN A TERTIARY CENTER IN SOUTHWEST BRAZIL.

Recent studies show an increase in nonalcoholic fatty liver disease (NAFLD) in populations with higher consumption of red meat, processed and cooked at high temperatures. On the other hand, the single nucleotide polymorphism rs738409 in the Patatin-like phospholipase domain containing 3 (PNPLA3) gene has been implicated in susceptibility to NAFLD and liver fibrosis. However, the synergistic effect between red meat consumption and the PNPLA3 gene polymorphism in NAFLD has not yet been evaluated. To evaluate the association between the presence of the polymorphism in the PNPLA3 gene and the consumption of macronutrients, including meat consumption and its cooking method among NAFLD patients. This was a cross-sectional study with 91 patients diagnosed with NAFLD by liver biopsy with genotyping for the polymorphism in the PNPLA3 gene were included. The consumption of calories and macronutrients was verified using the semi-quantitative food frequency questionnaire and the specific questionnaire on meat consumption. PNPLA3 gene polymorphism was analyzed by real-time polymerase chain reaction (RT-PCR) and anthropometric evaluation was realized. The mean BMI was 32.38±4.58 kg/m² and the waist circumference was 107±10 cm. On liver biopsy, 42% of patients had significant fibrosis (F≥2). The odds ratio of F≥2 was 2.12 for the GG group and 1.54 for the CG group, compared to the CC group. The mean caloric intake was 1170±463.20 kcal/d. The odds ratio in the CC group concerning high red meat consumption in comparison to low consumption was 1.33. For white meat, the odds ratio was 0.8 when comparing high and low intake, also in the CC group. High red meat intake and PNPLA3 gene polymorphism seem to synergistically affect NAFLD and liver fibrosis, requiring confirmation in a larger number of patients and in different populations.

Influence of the High Mobility Group A1 genetic polymorphism on indices of metabolic syndrome and insulin resistance in the Iraqi population: Case-control study

ABSTRACT: The high mobility group A1 gene (HMGA1) rs139876191 variant has been related to metabolic syndrome and type 2 diabetes, but data are lacking in Middle Eastern populations. The study aimed to assess whether the HMGA1 rs139876191 variant is associated with metabolic syndrome risk and whether this variant predicts the risk of insulin resistance. This case-control study was carried out at single center in Kirkuk city/ Iraq from February to August 2022. Polymorphisms in HMGA1 and genotyping were identified by Sanger sequencing of genomic DNA obtained from 91 Iraqi participants (61 patients with metabolic syndrome and 30 control). Lipid profile, serum (glucose and insulin), glycated hemoglobin, blood pressure, body mass index, and waist circumference were also measured. The high prevalence of the del/del genotype of rs139876191 was found. Minor allele frequency of rs139876191 was (0.16) in both metabolic syndrome and the control group. A non-significant difference in genotyping was identified between total metabolic syndrome and the control group. The del/ins variant was associated with significantly higher waist circumference, triglyceride(TG), low-density lipoprotein(LDL), very low-density lipoprotein(VLDL), and glycated hemoglobin(HbA1c) (P=0.03, 0.041, 0.007, 0.034, and 0.001 respectively), and with significantly lower high-density lipoprotein(HDL) (p=0.000). Linear regression analysis showed no significant effect of the variant (del/ins) on developing insulin resistance. Thus, rs139876191 polymorphism with del/ins genotype in the HMGA1 gene was not associated with metabolic syndrome risk but it was associated with indices of metabolic syndrome including waist circumference, TG, HDL, LDL, VLDL, and HbA1c. Besides, this variant did not predict the risk of insulin resistance.

Disentangling the causes of high polymorphism sharing in sympatric Petunia species from subtropical highland grasslands: insights from nuclear diversity.

Genetic polymorphism sharing between closely related and sympatric plant species could result from common ancestry, ancient or recent hybridization. Here we analyzed four Petunia species from the subtropical highland grasslands in southern South America based on nuclear diversity to disentangle the causes of high polymorphism sharing between them. We genotyped microsatellite loci, employed population genetic methods to estimate variability, species limits, and ancient and recent gene flow, and assigned individuals to genetic and taxonomic groups. Finally, we modeled evolutionary processes to determine the impact of Quaternary climate changes on species phylogenetic relationships. Our results indicated that genetic diversity was strongly influenced by expansion and habitat fragmentation during the Quaternary cycles. The extensive polymorphism sharing is mainly due to species' common ancestry, and we did not discard ancient hybridization. Nowadays, niche differentiation is the primary driver for maintaining genetic and morphological limits between the four analysed Petunia species and there is no recent gene flow between them.

Immune diversity in lophotrochozoans, with a focus on recognition and effector systems

Lophotrochozoa is one of the most species-rich but immunologically poorly explored phyla. Although lack of acquired response in a narrow sense, lophotrochozoans possess various genetic mechanisms that enhance the diversity and specificity of innate immune system. Here, we review the recent advances of comparative immunology studies in lophotrochozoans with focus on immune recognition and effector systems. Haemocytes and coelomocytes are general important yet understudied player. Comparative genomics studies suggest expansion and functional divergence of lophotrochozoan immune reorganization systems is not as “homogeneous and simple” as we thought including the large-scale expansion and molecular divergence of pattern recognition receptors (PRRs) (TLRs, RLRs, lectins, etc.) and signaling adapters (MyD88s etc.), significant domain recombination of immune receptors (RLR, NLRs, lectins, etc.), extensive somatic recombination of fibrinogenrelated proteins (FREPs) in snails. Furthermore, there are repeatedly identified molecular mechanisms that generate immune effector diversity, including high polymorphism of antimicrobial peptides and proteins (AMPs), reactive oxygen and nitrogen species (RONS) and cytokines. Finally, we argue that the next generation omics tools and the recently emerged genome editing technicism will revolutionize our understanding of innate immune system in a comparative immunology perspective.

Genotypic diversity and abiotic stress response profiling of short-grain aromatic landraces of rice (Oryza sativa L. Indica)

This study evaluated the physiological responses and genetic diversity of selected short-grain aromatic rice landraces of Northern Eastern Ghats of India to multiple abiotic stresses. Results revealed that drought, salt and flooding stress remarkably declined plant biomass, relative growth index (RGI), relative water content (RWC), leaf photosynthesis, PSII activity, SPAD relative index, and elevated effect was found in susceptible IR64 (susceptible check) variety. We employed molecular marker analysis to characterize 21 rice genotypes using 32 SSR primers related to drought, flooding and salinity tolerance QTLs. Our analysis suggests significantly high polymorphism (93.12%) in 96 loci. The mean value of polymorphism information content (PIC), marker index (MI) and resolving power (RP) and heterozygosity index (HI) were 0.326, 1.037, 1.558 and 0.420 respectively. The Jaccard’s similarity coefficient ranged from 0.158 to 0.846 with a mean genetic dissimilarity of 0.647. According to neighbor-joining method of clustering, all genotypes were grouped into two major and five sub-clusters which is concurrent with a very broad genetic base (K = 5) obtained with STRUCTURE analysis. Taken together, six aromatic genotypes Basubhoga, Dudhamani, Kalajeera, Laktimachi, Kuyerkuling and Tulasi are genetically very close to drought-tolerant (N22) and flooding tolerant (FR13A) cultivar whereas, salt-tolerant (Pokkali) very close to Sapuri and Muktabali. The degree of genetic variants obtained from this profiling could be useful for landrace conservation, selection and global implications for multiple abiotic stress tolerance.

Analysis of SSR Information of Flower Transcriptome in Loquat

In order to provide scientific basis for studying the genetic diversity and&nbsp;molecular marker-assisted breeding of loquat, new molecular markers of loquat&nbsp;were developed by analyzing flower transcriptome data.&nbsp;In&nbsp;this study, MIcroSAtellite (MISA) and Blast2GO&nbsp;were used for SSR searching, screening, identification, and analysis of non-redundant Unigenes, and Primer 3 was used for SSR primer design. A search found that 28&nbsp;617 Unigenes contained 44&nbsp;622 SSR loci, and the frequency of occurrence of SSR loci was 47.51%, and the total average distribution distance was 4.87 kb. Mononucleotide and dinucleotide repeats were the main repeat types of SSR in the loquat flower transcriptome that the SSR of mononucleotide and dinucleotide repeats accounted for 52.09%&nbsp;and 32.83%&nbsp;of the total SSR, respectively. The dominant repeat motifs were A/T and AG/CT, which accounted for 50.94%&nbsp;and 26.70%&nbsp;of the mononucleotide repeats and dinucleotide respectively, and the 65.79%&nbsp;length of motif was concentrated in 12~20 bp. Gene&nbsp;Ontology (GO) functional classification&nbsp;showed that 28&nbsp;617 loquat flower transcriptome Unigenes containing SSR loci were enriched in 51 GO terms of the 3 GO categories, and the biological process category involved the most GO terms (21). Primers for 34&nbsp;301 SSR sequences were successfully designed, with a success rate of 76.87%. It is shown by the analysis that the flower transcriptome SSR loci had high frequency, high distribution density, and high polymorphism potential and could provide abundant repeat types. These could provide scientific basis for&nbsp;studying&nbsp;quantitative trait loci mapping, molecular marker-assisted breeding, genome evolution, genetic diversity analysis.

Fagopyrum esculentum Moench plants’ photosynthetic activity correlation with efficient grading factors

About 95% of dry matter of agricultural crops is known to be provided by photosynthesis of plants. At the same time, its potential is realized by less than half: the efficiency of use of PAR by crops is usually in the range of 0.9 -1.5%, at best it reaches 2%. Obviously, activation of photosynthetic activity of plants by means of breeding can be considered as one of the promising ways to increase crop yields. This task is also relevant for buckwheat, which is a demanded food crop in the world market. In this regard, the purpose of the research was to study the possibility of using in buckwheat breeding the indicators of photosynthetic activity of plants based on their relationship with useful - economic characteristics of the variety. The results of the correlation analysis showed that the indicators of photosynthetic activity of buckwheat plants have a significant impact on the formation of the variety yield. Significant relationship of cultivar yield was revealed with leaf area (r=0.71), water use efficiency (r=0.68), photosynthetic potential (r=0.66) and photosynthetic intensity (r=0.35). Similar character of interrelation of these indicators in crop varieties was traced with harvesting index. It was found that the relationship between the structural and functional indicators of the leaf system of plants and the yield of buckwheat varieties does not remain constant, and significantly changes during the growing season of plants. The high polymorphism of the crop gene pool in terms of photosynthetic activity of plants and their significant relationship with the yield of the variety indicate the possibility of targeted breeding work in this direction.

Diversidade de cepas de Mycoplasma hyopneumoniae em suínos em terminação brasileiros

ABSTRACT: Mycoplasma hyopneumoniae is one of the most challenging respiratory pathogens involved with swine pneumonia worldwide, responsible for a chronic infection with high morbidity, which predisposes secondary bacterial infections in growing and finishing pigs. Advances in diagnostic techniques allowed identification of genetic characteristics associated with high antigenic and proteomic variability among bacterial strains. This study aimed to evaluate the genetic diversity of M. hyopneumoniae strains in lungs with pneumonic lesions obtained from 52 pig farms located in Minas Gerais, one of the largest swine production states in Brazil. Genotyping was performed using multilocus variable number of tandem repeat (VNTR) analysis (MLVA), targeting two loci encoding P97 and P146 adhesins VNTR. The results showed that this agent is widely disseminated in pig farms and there is a high polymorphism of M. hyopneumoniae variants circulating in the state of Minas Gerais. Different M. hyopneumoniae genotypes are randomly distributed in several regions of the state, with no specific geographic population structure pattern. M. hyopneumoniae association with viral agents was sporadic (3.17% with Influenza A and 1.9% with PCV2).

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.