Specific DNA Markers Research Articles

Genetic and environmental impact on variation in the palatal dimensions in permanent dentition: a twin study.

The objective of this study was to assess the relative contributions of genetic and environmental factors to variation in palatal parameters in twins with completed maxillary growth. The subjects of this study comprised digital dental casts of 50 monozygotic and 35 dizygotic twin pairs. The subjects' average age was 17.95 ± 2.83years. Zygosity determination was carried out using 15 specific DNA markers and an amel fragment of the amelogenin gene. The interdental distances were measured between selected dental landmarks at the occlusal and gingival planes. The palatal height, surface area and volume were measured between the gingival plane and the midpalate suture. High heritability estimates were observed for all transverse intra-arch measurements. The palate height (a2 = 0.8), dental arch width in the molar area (a2 = 0.86), palatal surface area (a2 = 0.61) and palate volume (a2 = 0.69) were under strong additive genetic control. Moderate genetic dominance was observed for dental arch widths at the gingival line in the canine (d2 = 0.5) and premolar regions (d2 = 0.78-0.81). Sexual dimorphism was shown, with males exhibiting a greater arch width, palate surface area and volume than females (p < 0.01). The majority of palate parameters variation in twins was controlled by genetic effects, and most were highly heritable.

DNA-Based Authentication of Some Selected Hyper-Accumulator Species of Marigold Using Plastid Specific DNA Marker rbcL and matK

DNA-Based Authentication of Some Selected Hyper-Accumulator Species of Marigold Using Plastid Specific DNA Marker rbcL and matK

Evaluation of Agronomic Traits and Allele Specific DNA Markers Related to Some Disease and Quality Traits in Mutant Karakılçık M4 Individuals

Karakılçık (KK) is a landrace, of which both bread and durum wheat forms exist. This is the first study that reports mutation induction and detection with agronomic traits and allele specific markers on KK durum wheat landrace. In the study, KK landrace was induced with chemical mutation using sodium azide (NaN3) (3 mM) mutagen to improve agronomic traits. In the research, KK genotype and the 13 M4 individuals (KK-1 to KK-13) were used as plant materials. According to the results, the shortest mutant genotype was KK-10 (125.80 cm), with the highest protein ratio (18.50%) and wet gluten ratio (37.10%), while KK-9 genotype had the highest grain yield (4285.6 kg ha-1). The average polymorphism information content (PIC) was calculated as 0.97, while the average allele number was 15.2 per marker. Glu-B1 (Bx7OE primer) allele was determined on KK-11 and KK-13 genotypes. Wx-A1 allele was found on KK-1, KK-2, KK-4, KK-5 and KK-7 genotypes. Sr49 allele (Sun209) was determined on KK-5 genotype, while Yr45 allele (Xwgp118) was detected on KK-10 genotype. In addition, the high protein content allele Gpc-B1 (UHW89 primer) was found on KK-1, KK-2, KK-3 and KK-4 genotypes. Based on the principal component biplot analysis, it was determined that there was a positive relationship between grain yield (GY) with test weight (TW), grain number and weight per spike (GNS and GWS), and negative relationship with the other traits.

Utilization of Circulating Tumor DNA in the Surveillance Setting.

National guidelines give recommendations regarding cancer surveillance follow-up. In many early staged cancers radiographic imaging and labs are not routinely recommended unless patients are symptomatic. This can cause a gap in care because commonly when patients present symptomatically, they have progressed and transitioned to later-stage cancer. This study demonstrates how circulating tumor DNA (ctDNA) can be used alongside current guidelines to help screen patients for recurrence in the surveillance setting. A retrospective chart review was performed. Fifty-five charts were reviewed of patients who received ctDNA testing drawn in follow-up after their primary tumor or metastatic disease was rendered surgically or radiographically disease-free. A customized signature profile, using the sixteen most prevalent genomic markers from a patient's primary tumor or biopsy, is developed by whole-exome sequencing. Serial blood draws are then drawn to assess for specific DNA markers using polymerase chain reaction (PCR) assays. Fifty-five charts were reviewed in patients who had stage I-III breast, pancreatic, melanoma, and colorectal cancer. Of the fifty-five, a total of seven had a positive test. Of the seven positive tests, six patients were found to have recurrent/metastatic disease. One positive test was performed four weeks postoperatively but by the second draw ten weeks postoperatively had non-detectable ctDNA. The remaining forty-eight patients had non-detectable ctDNA levels and to date have not had any evidence of recurrence based on standard follow-up guidelines. The utilization of ctDNA in the surveillance setting can be used to help detect recurrence in the surveillance setting.

Molecular quantification for differentiation of fresh and dried Jinqian Baihua She

Freshly-used crude drugs have unique functions and advantages in TCM practice of treating diseases. Jinlong Capsule is a patent traditional Chinese medicine product effective for treatment of hepatocarcinoma, and fresh Jinqian Baihua She (JBS, the body of juvenile Bungarus multicinctus) is one of its important ingredients. The emergence of counterfeit fresh JBS, often identified as dried JBS with almost identical appearance, poses a difficult problem in the quality control of the product. Herein we report a molecular quantification-based method for differentiation of fresh and dried JBS by determining the copy number of a specific DNA marker in the samples. Using species-specific primers and TaqMan probes, we established a real-time quantitative PCR system for amplification of a fragment in the 658-bp cytochrome oxidase subunit I (COI) region from JBS specimens. The amplicon copy number in the muscle tissues ranged from 1.14 × 107 to 4.83 × 107 copies/mg in fresh JBS samples, as compared with 1.13 × 105−8.91 × 106 copies/mg in dried JBS samples. Based upon Fisher discriminant analysis, we used 1.27 × 107 copies/mg as the cut-off value for differentiating fresh and dried JBS, which was validated in the single-blinded validation test of fresh and dried JBS samples. This qPCR system may provide an efficient means for accurate identification of fresh JBS to improve the quality control of the medicinal product.

Heritability of cephalometric variables of airway morphology in twins with completed active growth

BackgroundThe interplay between genetic and environmental impacts on dental and facial morphology has been widely analyzed, but little is known about their relative contributions to airway morphology. The aim of this study was to evaluate the genetic and environmental influences on the cephalometric variables of airway morphology in a group of postpubertal twins with completed craniofacial growth.Materials and methodsThe materials comprised lateral head cephalograms of 94 pairs of twins (50 monozygotic, 44 dizygotic) with completed craniofacial growth. Zygosity was determined using 15 specific DNA markers. The computerized cephalometric analysis included 22 craniofacial, hyoideal, pharyngeal structural linear and angular variables. Genetic analysis and heritability estimation were performed using maximum likelihood genetic structural equation modeling (GSEM). Principal component analysis (PCA) was used to assess the correlations between cephalometric measurement variables.ResultsUpper airway dimensions showed moderate to high genetic determination (SPPW-SPP and U-MPW: a2 = 0.64 and 0.5, respectively). Lower airway parameters showed only common and specific environmental determination (PPW-TPP a2 = 0.24, e2 = 0.38; LPW-V c2 = 0.2, e2 = 0.63; PCV-AH c2 = 0.47, e2 = 0.28). The relationship between the maxilla and the hyoid bone (for variables PNS-AH, ANS-AH d2 = 0.9, 0.92, respectively) showed very strong additive genetic determination. The size of the soft palate was affected by additive and dominant genes. Its length (SPL) was strongly influenced by dominant genes, while its width (SPW) showed a moderate additive genetic influence. Owing to correlations in the behavior of variables, the data could be expressed in 5 principal components that jointly explained 36.8% of the total variance.ConclusionsThe dimensions of the upper airway are strongly determined by genes, while the parameters of the lower airway depend mainly on environmental factors.Trial registrationThe protocol has been approved by the Kaunas Regional Ethical Committee (No. BE – 2–41., May 13, 2020).

Toward reducing the immunogenic potential of wheat flour: identification and characterization of wheat lines missing omega-5 gliadins encoded by the 1D chromosome.

Eleven wheat lines that are missing genes for the 1D-encoded omega-5 gliadins will facilitate breeding efforts to reduce the immunogenic potential of wheat flour for patients susceptible to wheat allergy. Efforts to reduce the levels of allergens in wheat flour that cause wheat-dependent exercise-induced anaphylaxis are complicated by the presence of genes encoding omega-5 gliadins on both chromosomes 1B and 1D of hexaploid wheat. In this study, we screened 665 wheat germplasm samples using gene specific DNA markers for omega-5 gliadins encoded by the genes on 1D chromosome that were obtained from the reference wheat Chinese Spring. Eleven wheat lines missing the PCR product corresponding to 1D omega-5 gliadin gene sequences were identified. Two of the lines contained the 1BL·1RS translocation. Relative quantification of gene copy numbers by qPCR revealed that copy numbers of 1D omega-5 gliadins in the other nine lines were comparable to those in 1D null lines of Chinese Spring, while copy numbers of 1B omega-5 gliadins were like those of Chinese Spring. 2-D immunoblot analysis of total flour proteins from the selected lines using a specific monoclonal antibody against the N-terminal sequence of omega-5 gliadin showed no reactivity in regions of the blots containing previously identified 1D omega-5 gliadins. Interestingly, RP-UPLC analysis of the gliadin fractions of the selected lines indicated that the expression of omega-1,2 gliadins was also significantly reduced in seven of the lines, implying that 1D omega-5 gliadin and 1D omega-1,2 gliadin genes are tightly linked on the Gli-D1 loci of chromosome 1D. Wheat lines missing the omega-5 gliadins encoded by the genes on 1D chromosome should be useful in future breeding efforts to reduce the immunogenic potential of wheat flour.

Thermoregulation in Sheep and Goats: A Review

Thermoregulation is the capability of an animal to maintain its core internal temperature by homeostasis. Small ruminants like sheep and goats acclimate to different environmental changes and often perform better during heat stress than other ruminants. Adapting small ruminants to exceptional weather events occurs through behavioral, genetic, physiological, and morphological mechanisms. Small ruminants can mitigate the consequences of thermal stress using behavioral strategies such as consuming more water, looking for shade, consuming less feed, standing instead of lying down behavior, and other morphological mechanisms such as size, shape, coat color, coat depth, pigmentation, and fat storage. Small ruminants also respond to thermal changes through physiological mechanisms such as variations in respiration, heart rate, core temperature, sweating rate, metabolic rate, and endocrine functions. From the genetic point of view, animals could inherit traits that favor their survival in specific climatic conditions. The adaptation of small ruminants to different thermal environments is determined by an elaborate network of genes with specific genome-wide DNA markers improving toleration to excessive heat. Therefore, genetic identification and analysis of thermotolerance genes should be applied as markers in breeding programs.

Molecular-based race classification of Pyrenophora tritici-repentis causing tan spot of wheat in Japan.

Tan spot, a foliar disease of Triticum spp. such as bread wheat (T. aestivum L.) and durum wheat (T. turgidum ssp. durum (Desf.) Husn.) caused by the filamentous fungus Pyrenophora tritici-repentis (Died.) Drechsler leads to serious losses of crop yield and quality in some areas in Japan. P. tritici-repentis is classified into eight races according to the combinations of three necrotrophic effectors, PtrToxA, PtrToxB, and PtrToxC encoded by ToxA, ToxB, and ToxC1, respectively. Race classification has been based on reaction of a differential variety to necrotrophic effectors, which is tested by inoculation. Recent identification of the Tox genes and development of specific DNA markers have enabled us to classify races of P. tritici-repentis collected in Japan by Tox gene genotyping. We found that 17 strains collected from Triticum spp. in Japan were mainly race 1 or 2, because they carried ToxA as a toxin gene by current race classification; wheat genotype tsn1 is resistant to ToxA. Establishment of wheat cultivars carrying tsn1 would be most effective for decreasing agronomic losses caused by the disease in Japan.

Molecular and Cytogenetic Identification of Wheat-Thinopyrum intermedium Double Substitution Line-Derived Progenies for Stripe Rust Resistance.

Thinopyrum intermedium (2n = 6x = 42, JJJSJSStSt) has been hybridized extensively with common wheat and proven to be a valuable germplasm source for improving disease resistance and yield potential of wheat. A novel disease-resistant wheat-Th. intermedium double substitution line X479, carrying 1St(1B) and 4St-4JS (4B), was identified using multi-color non-denaturing fluorescence in situ hybridization (ND-FISH). With the aim of transferring Thinopyrum-specific chromatin to wheat, a total of 573 plants from F2 and F3 progenies of X479 crossed with wheat cultivar MY11 were developed and characterized using sequential ND-FISH with multiple probes. Fifteen types of wheat-Thinopyrum translocation chromosomes were preferentially transmitted in the progenies, and the homozygous wheat-1St, and wheat-4JSL translocation lines were identified using ND-FISH, Oligo-FISH painting and CENH3 immunostaining. The wheat-4JSL translocation lines exhibited high levels of resistance to stripe rust prevalent races in field screening. The gene for stripe rust resistance was found to be physically located on FL0-0.60 of the 4JSL, using deletion lines and specific DNA markers. The new wheat-Th. intermedium translocation lines can be exploited as useful germplasms for wheat improvement.

Characterization of Vibrio parahaemolyticus isolated from stool specimens of diarrhea patients in Nantong, Jiangsu, China during 2018-2020.

Vibrio parahaemolyticus is the leading cause of acute seafood-associated gastroenteritis worldwide. The aim of this study was to investigate the presence of virulence genes, biofilm formation, motor capacities and antimicrobial resistance profile of V. parahaemolyticus isolates isolated from clinical samples in Nantong during 2018–2020. Sixty-six V. parahaemolyticus strains isolated from stool specimens of diarrheal patients were examined. The PCR results showed that there were two tdh+trh+ isolates, four tdh-trh- isolates and sixty tdh+trh- isolates, accounting for 3.0%, 6.1% and 90.9%, respectively. All the tdh carrying isolates manifested the positive reactions for the Kanagawa phenomenon (KP) test. Most of the isolates harbored at least one of the specific DNA markers of ‘pandemic group’ strains, suggesting that the dominant isolates of V. parahaemolyticus in Nantong might belong to the new O3: K6 or its serovariants. All tdh+ isolates possessed the Vp-PAI genes, but no tdh-trh- isolates carried the T3SS2 genes. All isolates were biofilm producers and had relatively strong motor capacities. In addition, the V. parahaemolyticus isolates were resistant to ampicillin (98.5%), cefuroxime (75.6%), cefepime (66.7%), piperacillin (59.1%) and ampicillin/sulbactam (50.0%), but sensitive to ciprofloxacin (100.0%), levofloxacin (100.0%), trimethoprim-sulfamethoxazole (98.5%), gentamicin (98.5%), amikacin (97%), meropenem (71.2%), and ceftazidime (56.1%). Multidrug-resistant isolates in clinical might be related to the inappropriate use of antimicrobials in aquaculture.

Genetic and nuclear DNA content variation of stevia (Stevia rebaudiana Bertoni) accessions grown in Turkey

The objectives of this study were to make morphological and molecular characterization of Turkish stevia accessions. The field data showed significant variations (P &lt; 0.05) for all morphological parameters (plant height, number of main stems per plant, number of secondary stems, fresh and herb yields) exception with number of secondary stems. The primers of MtP5CS, AtNHX1, MtProDH, Mt-Actin MtSOS1and MtSOS2 genes were used as loci specific DNA markers. All markers were amplified in Stevia genome and provided a mean of 74.16% polymorphism rate. Flow cytometer analysis showed no statistically significant differences (P &lt; 0.16) for 2C DNA content with a mean of 1.62 pg. The UPGMA analysis revealed that Samsun accession was distinctly separated from the others and had the lowest 2C DNA content (1.52 pg). This study first time showed that the stevia accessions grown in Turkey have limited genetic and no nuclear DNA content variations. The results also revealed that gene targeted functional markers associated with salt and drought tolerance have a great potential to be used as DNA markers to determine the genetic variation in plants

Methylated DNA markers in urine aid in the selective identification of patients with prostate cancer as well as clinically significant pathology.

5091 Background: Controversy surrounding prostate-specific antigen (PSA) based screening for prostate cancer (PCa) highlights the need for non-invasive assays that better discriminate patients with and without clinically significant prostate cancer (csPCa). Such distinction avoids overtreatment in patients with absent or indolent disease while capturing pathology that would derive benefit from intervention. We analyzed the presence of specific methylated DNA markers (MDMs) within urine samples of patients with biopsy proven PCa and assessed the ability to discriminate these patients from healthy controls with no clinical suspicion for PCa. Methods: 24 healthy volunteers with no clinical suspicion for PCa were age-matched to 24 patients with biopsy-confirmed disease across all Gleason scores. Urine collected from subjects was centrifuged with the cell-free supernatant analyzed in a blinded fashion for methylation signal within specific DNA sequences across 14 genes ( HES5, ZNF655, ITPRIPL1, MAX.chr3.193, SLCO3A1, CHST11, SERPINB9, WNT3A, KCNB2, GAS6, AKR1B1, MAX.chr3.727, GRASP, ST6GALNAC2) by target enrichment long-probe quantitative-amplified signal assays. A patient was considered to have a positive MDM panel if any individual marker exceeded the corresponding100% specificity cut-off value (overall MDM panel specificity of 100%). MDM panel positivity was used to evaluate the sensitivity for distinguishing patients with PCa (any Gleason score) from controls as well as discriminate csPCa cancers from PCa Gleason 6. Results: Median age of healthy controls and PCa patients was 70 years (IQR 67-72) and 65 years (IQR 61-71), respectively. Median PSA was 6.4 (IQR 4.9-9.0) among PCa patients, including median PSA of 5 (IQR 4.0-6.1) for Gleason 6, and 7.8 (IQR 5.1-9.2) for Gleason ≥7 disease. Gleason 6, Gleason 7, and Gleason 8+ cancer was noted in 8, 10, and 6 patients, respectively. Utilizing an overall specificity cut-off of 100% for discriminating normal controls from PCa cases across the MDM panel revealed an overall sensitivity of 83% (95% CI: 63-95%) for detection of PCa (6 of 8 Gleason 6, 9 of 10 Gleason 7, 5 of 6 Gleason 8+) and 88% (95% CI: 62-98%) for csPCa (Gleason ≥ 7). When considering a 100% specificity threshold for controls and Gleason 6 patients, the sensitivity the MDM panel was 69% (95% CI: 41-89%) for csPCa (6 of 10 Gleason 7, 5 of 6 Gleason 8+). Conclusions: We describe a panel of 14 MDMs within urine that offer high specificity and sensitivity for detection of prostate cancers as well as selective identification of clinically significant disease states. Prospective comparison between urine MDMs and PSA blood testing is necessary to discern the differential clinical impact of each screening methodology.

Development of SCAR Markers to Identify Medicinal Cultivars of Paeonia lactiflora.

Paeoniae Radix, the dried root of Paeonia lactiflora, is one of the most important ingredients in Kampo medicine. It is known that Paeoniae Radix is derived from various P. lactiflora cultivars, including medicinal and horticultural cultivars, and that cultivar identification by DNA analysis has been unsuccessful. We attempted to develop sequence characterized amplified region (SCAR) markers as useful DNA markers for the identification and herbal medicine authentication of two cultivars developed in Japan, 'Bonten' and 'Kitasaisho,' which are two superior medicinal strains of P. lactiflora. Sequence-related amplified polymorphism (SRAP) analysis was conducted on fourteen P. lactiflora cultivars, and polymorphic fragments specific to 'Bonten' or 'Kitasaisho' were detected. Then, SCAR markers for 'Bonten' and 'Kitasaisho' were developed from the sequence information of these polymorphic fragments. Thirty cultivars of P. lactiflora and five herbal medicine samples were used to validate the specificity of the developed SCAR markers. As a result, we confirmed that our SCAR markers can identify 'Bonten' or 'Kitasaisho' from the plant samples and the herbal medicine samples. Thus, we have successfully designed two highly specific DNA markers and established an easy, rapid, and cost-efficient method to identify specific cultivars of P. lactiflora. Our SCAR markers are expected to contribute to the maintenance of P. lactiflora cultivars such as 'Bonten' as superior medicinal strains, the development of more elite cultivars in the future, and the deterrence of outflow of original cultivars to foreign countries.

Application of a Forensic DNA Extraction System for Cannabis sativa Seed Identification.

Identification of Cannabis sativa seeds is crucial for law authorities fighting drug abuse and global trafficking. However, because they lack chemicals that are routinely used to pinpoint C. sativa plants, their identification becomes far more challenging. Germinating the seeds requires tremendous resources, is time consuming and is not effective when dealing with nonviable seeds. Botanical identification relies on well-trained experts. In recent years, laboratories have started to use specific DNA markers to achieve this goal. Real-time quantitative polymerase chain reaction (qPCR) was found to be a simple and efficient approach. However, seed DNA extraction is often labor intensive and involves many steps, which may also lead to DNA loss and contaminations. In the present study, we explored whether the PrepFiler™ Express Forensic DNA Extraction Kit, which is used in our DNA casework forensic laboratory, can reduce the work required for this critical step. We show that this kit has several advantages when compared with a dedicated plant extraction kit. In addition, we show that the combination of this extraction method and qPCR can enable high-throughput C. sativa seed identification.

First report of strong phosphine resistance in stored grain insects in a far northern tropical region of Australia, combining conventional and genetic diagnostics

Although phosphine resistance monitoring and management programs are well advanced in Australia, the tropical northern part of the continent has received little attention. To address this, grain storages were sampled in the Townsville region in the Burdekin river catchment area of northern Queensland, and insect populations were subjected to resistance testing. Sampling of storages including silos, food processing facilities and feedlots was carried out during July to August 2019 and February to March 2020. Of the several species collected, populations of two major pest species, Rhyzopertha dominica and Tribolium castaneum were subjected to phenotypic resistance and molecular screening using discriminating doses and gene specific DNA marker, respectively. Utilising phenotypic assay, of the 17 populations of R. dominica, 12 were diagnosed as weakly resistant and five as strongly resistant; whereas of the 34 populations of T. castaneum, two were found to be susceptible to phosphine, 15 were determined as weakly resistant and 17 as strongly resistant. The molecular diagnostics, however, determined rph2 alleles for strong resistance in some populations each of R. dominica and T. castaneum that were diagnosed as weakly resistant in the phenotypic assay. The most prevalent rph2 alleles were found to be P49S and K142E in R. dominica populations and P45S and G131S in T. castaneum populations. Our results highlight the need of more comprehensive study towards determining the level of pests and resistance risks in this region.

Short Communication: Molecular study on mt-DNA COX2 gene of Sumatran elephant (Elephas maximus sumatranus)

Abstract. Wibowo DS, Widiyanti R, Asvan M, Restanti PD, Wijayanto H. 2021. Short Communication: Molecular study on mt-DNA COX2 gene of Sumatran elephant (Elephas maximus sumatranus). Biodiversitas 22: 1063-1068. Sumatran elephant is the only subspecies of Asian elephants that receives a critically endangered status from the International Union for Conservation and Nature Resources (IUCN). Identifying the genetic marker of Sumatran elephants is, therefore, important for their conservation. This study aimed to identify the Sumatran elephant based on specific mitochondrial DNA markers of the Cytochrome c oxidase subunit II (COX2) gene. It is an exploratory research considering the limited data and research about the genetic, especially the COX2 of Sumatran elephant (Elephas maximus sumatranus). Forward and reverse sequencing of PCR products was conducted using the primary COX2 from Sumatran elephant samples. The results of the subsequent gene sequencing were aligned with the sequences of other Asian elephants from Genbank using Clustal W software and analyzed using the MEGA program version 6.06. The analysis of genetic distance based on COX2 constituent nucleotides calculated with Kimura’s two-parameter method showed that the genetic distance between Elephas maximus sumatranus and Elephas maximus outside of Sumatra was 0.25%. The phylogenetic trees analyzed using the maximum-likelihood based on nucleotide sequences showed a high homogeneity. The ratio of Elephas maximus sumatranus with Elephas maximus shows levels of nucleotide mutations which are nine nucleotides and four nucleotides. These results indicated that the COX2 gene could not identify the individual species of Sumatran elephant because of the high intraspecies homogeneity, but it detected the interspecies divergence clustered in Asian elephant clade.

Evaluation of resistance to powdery mildew and identification of resistance genes in wheat cultivars.

Wheat powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), is a serious disease of wheat worldwide that can cause significant yield losses. Growing resistant cultivars is the most cost-effective and eco-soundly strategy to manage the disease. Therefore, a high breeding priority is to identify genes that can be readily used either singly or in combination for effective resistance to powdery mildew and also in combination with genes for resistance to other diseases. Yunnan Province, with complex and diverse ecological environments and climates, is one of the main wheat growing regions in China. This region provides initial inoculum for starting epidemics of wheat powdery mildew in the region and other regions and thus, plays a key role in the regional and large-scale epidemics of the disease throughout China. The objectives of this study were to evaluate seedling resistance of 69 main wheat cultivars to powdery mildew and to determine the presence of resistance genes Pm3, Pm8, Pm13, Pm16, and Pm21in these cultivars using gene specific DNA markers. Evaluation of 69 wheat cultivars with six Bgt isolates showed that only four cultivars were resistant to all tested isolates, indicating that the overall level of powdery mildew resistance of Yunnan wheat cultivars is inadequate. The molecular marker results showed that 27 cultivars likely have at least one of these genes. Six cultivars were found likely to have Pm3,18 likely to have Pm8,5 likely to have Pm16,and 3 likely to have Pm21. No cultivar was found to carry Pm13. The information on the presence of the Pmresistance genes in Yunnan wheat cultivars can be used in future wheat disease breeding programs. In particular, cultivars carrying Pm21, which is effective against all Bgtraces in China, should be pyramided with other effective genes to developing new cultivars with durable resistance to powdery mildew.

Genetic Diversity of Selected Rice Genotypes under Water Stress Conditions.

Drought is the most challenging abiotic stress for rice production in the world. Thus, developing new rice genotype tolerance to water scarcity is one of the best strategies to achieve and maximize high yield potential with water savings. The study aims to characterize 16 rice genotypes for grain and agronomic parameters under normal and drought stress conditions, and genetic differentiation, by determining specific DNA markers related to drought tolerance using Simple Sequence Repeats (SSR) markers and grouping cultivars, establishing their genetic relationship for different traits. The experiment was conducted under irrigated (normal) and water stress conditions. Mean squares due to genotype × environment interactions were highly significant for major traits. For the number of panicles/plants, the genotypes Giza179, IET1444, Hybrid1, and Hybrid2 showed the maximum mean values. The required sterility percentage values were produced by genotypes IET1444, Giza178, Hybrid2, and Giza179, while, Sakha101, Giza179, Hybrid1, and Hybrid2 achieved the highest values of grain yield/plant. The genotypes Giza178, Giza179, Hybrid1, and Hybrid2, produced maximum values for water use efficiency. The effective number of alleles per locus ranged from 1.20 alleles to 3.0 alleles with an average of 1.28 alleles, and the He values for all SSR markers used varied from 0.94 to 1.00 with an average of 0.98. The polymorphic information content (PIC) values for the SSR were varied from 0.83 to 0.99, with an average of 0.95 along with a highly significant correlation between PIC values and the number of amplified alleles detected per locus. The highest similarity coefficient between Giza181 and Giza182 (Indica type) was observed and are susceptible to drought stress. High similarity percentage between the genotypes (japonica type; Sakha104 with Sakha102 and Sakha106 (0.45), Sakha101 with Sakha102 and Sakha106 (0.40), Sakha105 with Hybrid1 (0.40), Hybrid1 with Giza178 (0.40) and GZ1368-S-5-4 with Giza181 (0.40)) was also observed, which are also susceptible to drought stress. All genotypes are grouped into two major clusters in the dendrogram at 66% similarity based on Jaccard’s similarity index. The first cluster (A) was divided into two minor groups A1 and A2, in which A1 had two groups A1-1 and A1-2, containing drought-tolerant genotypes like IET1444, GZ1386-S-5-4 and Hybrid1. On the other hand, the A1-2 cluster divided into A1-2-1 containing Hybrid2 genotype and A1-2-2 containing Giza179 and Giza178 at coefficient 0.91, showing moderate tolerance to drought stress. The genotypes GZ1368-S-5-4, IET1444, Giza 178, and Giza179, could be included as appropriate materials for developing a drought-tolerant variety breeding program. Genetic diversity to grow new rice cultivars that combine drought tolerance with high grain yields is essential to maintaining food security.

Making environmental DNA (eDNA) biodiversity records globally accessible

AbstractEnvironmental DNA (eDNA) metabarcoding, where specific DNA markers (barcodes) are purified from the environment, sequenced, and used to identify organisms, is revolutionizing biodiversity science. Researchers, industry, and governments are increasingly incorporating eDNA surveys into their toolkits for biomonitoring because of their high accuracy, taxonomically holistic lens, and ease of deployment. Yet, the full value of this rich and revolutionary technique is not being realized because eDNA data are rarely maintained in consistent formats or on open platforms that facilitate easy re‐use or integration with other data layers. Here, we discuss opportunities to improve the accessibility and “FAIRness” of eDNA records with the aim to maximize the value of this remarkable source of information on environmental state and change.