Mapping Of Resistance Research Articles

High-resolution genetic mapping and identification of candidate genes for the wheat stem rust resistance gene Sr8155B1

Stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), threatens global wheat production. Development of cultivars with increased resistance to stem rust by identification, mapping, and deployment of resistance genes is the best strategy for controlling the disease. In this study, we performed fine mapping and characterization of the all-stage stem rust resistance (Sr) gene Sr8155B1 from the durum wheat line 8155-B1. In seedling tests of biparental populations, Sr8155B1 was effective against six Chinese Pgt races tested. In a segregating population of 5060 gametes, Sr8155B1 was mapped to a 0.06-cM region flanked by markers Pku2772 and Pku43365, corresponding to 1.5- and 2.7-Mb regions in the Svevo and Chinese Spring reference genomes. Both regions include several typical nucleotide-binding leucine-rich repeat (NLR) and protein kinase genes that represent candidate genes. Among them, three NLR genes and three receptor-like protein kinases were highly polymorphic between the parental lines and their transcripts were upregulated in the homozygous resistant line TdR2 relative to its susceptible sister line TdS4. Four markers (Pku2772, Pku43365, Pku2950, and Pku3721) developed in this study, together with seedling resistance responses, correctly predicted Sr8155B1 absence or presence in 78 tetraploid wheat genotypes tested. The presence of Sr8155B1 in tetraploid wheat accessions CItr 14916, PI 197492, and PI 197493 was confirmed by mapping in three F2 populations. The genetic map and linked markers developed in this study may accelerate the deployment of Sr8155B1-mediated resistance in wheat breeding programs.

Investigating the role of film thickness on the physical properties of sol-gel coated CuO thin films: Discussing its potentiality in optoelectronic applications

In the present study, Cupric oxide thin films with varying thicknesses were successfully fabricated on a glass substrate at room temperature via dip coating technique. Highly crystalline CuO films with monoclinic symmetry were examined from XRD which was further confirmed with the help of Raman spectra. FESEM results showed a uniform coating surface with nano-sized grains without any agglomerations. The elemental composition of Cu and O atoms is in a 1:1 stoichiometric ratio for samples having higher thickness values. Strong absorption in the visible and nearby IR region makes the sample a viable choice in the field of photovoltaics. The estimated band gap values from the Tauc plot ranges from 1.10 eV to 1.26 eV. All the samples exhibited a p-type nature and their uniformity of resistance over the film surface was examined by resistance mapping. Hall measurements indicated the direct proportionality of sample resistivity with thickness.

Mixed infections in genotypic drug-resistant Mycobacterium tuberculosis

Tuberculosis disease (TB), caused by Mycobacterium tuberculosis, is a major global public health problem, resulting in more than 1 million deaths each year. Drug resistance (DR), including multi-drug (MDR-TB), is making TB control difficult and accounts for 16% of new and 48% of previously treated cases. To further complicate treatment decision-making, many clinical studies have reported patients harbouring multiple distinct strains of M. tuberculosis across the main lineages (L1 to L4). The extent to which drug-resistant strains can be deconvoluted within mixed strain infection samples is understudied. Here, we analysed M. tuberculosis isolates with whole genome sequencing data (n = 50,723), which covered the main lineages (L1 9.1%, L2 27.6%, L3 11.8%, L4 48.3%), with genotypic resistance to isoniazid (HR-TB; n = 9546 (29.2%)), rifampicin (RR-TB; n = 7974 (24.4%)), and at least MDR-TB (n = 5385 (16.5%)). TB-Profiler software revealed 531 (1.0%) isolates with potential mixed sub-lineage infections, including some with DR mutations (RR-TB 21/531; HR-TB 59/531; at least MDR-TB 173/531). To assist with the deconvolution of such mixtures, we adopted and evaluated a statistical Gaussian Mixture model (GMM) approach. By simulating 240 artificial mixtures of different ratios from empirical data across L1 to L4, a GMM approach was able to accurately estimate the DR profile of each lineage, with a low error rate for the estimated mixing proportions (mean squared error 0.012) and high accuracy for the DR predictions (93.5%). Application of the GMM model to the clinical mixtures (n = 531), found that 33.3% (188/531) of samples consisted of DR and sensitive lineages, 20.2% (114/531) consisted of lineages with only DR mutations, and 40.6% (229/531) consisted of lineages with genotypic pan-susceptibility. Overall, our work demonstrates the utility of combined whole genome sequencing data and GMM statistical analysis approaches for providing insights into mono and mixed M. tuberculosis infections, thereby potentially assisting diagnosis, treatment decision-making, drug resistance and transmission mapping for infection control.

Hydrostratigraphy and hydrogeophysical studies to delineate fresh and saline aquifer boundaries in Lesser Cholistan of Pakistan.

The differentiation of saline water and fresh water interfaces is a key objective in ground water exploration and management. Bahawalpur is the twelfth biggest metropolitan area of Pakistan situated in south Punjab near the bank of River Sutlej and lies at 29°59'55" N latitude and 73°15'12" E longitude at an elevation of 521 ft AMSL in the Cholistan area close to the Thar abandon. The study area comprised of Lesser Cholistan experiencing acute shortage of water for inhabitants and livestock as well. The occurrence of fresh water is also challenging because of high salinity in groundwater. The present study is intended to identify hotspots of fresh groundwater zones. To achieve the goal, vertical electrical resistivity and borehole data are used to mark fresh and saline interfaces in groundwater. To achieve the results 230 vertical electric sounding were performed in the study area. A total of 3 to 5 geo-electric layers are identified with modeling along with the processing and interpretation of resistivity data. In the study area, resistivity values are classified as very high (>230 Ω-m), high (230-100 Ω-m), medium (100-40 Ω-m), low (40-20 Ω-m) and very low (<20 Ω-m). Borehole data is used to interpret subsurface lithologies and to calibrate the modeled resistivity curves. The electric resistivity data indicates that thick layers of Quaternary sediments is present in the subsurface that is primarily composed of clay, silt, sand, gravels and some kanker. Inversion technique is applied to generate 2D subsurface resistivity maps to delineate fresh and saline water zones. The generated 2D resistivity maps at variable depth above and below water table and formation resistivity maps are successfully utilized to differentiate fresh and saline water zones. The identification of a saline water aquifer within sediments rich in clay was made possible by the observation of very low resistivity measurements in the southern region. Conversely, the detection of relatively high resistivity values, coupled with the presence of sand and gravel deposits in the northern section of the lesser Cholistan area, provided compelling evidence of the existence of fresh groundwater. These findings have significant implications for the management of water resources in the region, as they provide valuable insights into the distribution and availability of groundwater resources for future use.

Genome-wide association mapping and genomic prediction for late blight and potato cyst nematode resistance in potato (Solanum tuberosum L.).

Potatoes are an important source of food for millions of people worldwide. Biotic stresses, notably late blight and potato cyst nematodes (PCN) pose a major threat to potato production worldwide, and knowledge of genes controlling these traits is limited. A genome-wide association mapping study was conducted to identify the genomic regulators controlling these biotic stresses, and the genomic prediction accuracy was worked out using the GBLUP model of genomic selection (GS) in a panel of 222 diverse potato accessions. The phenotype data on resistance to late blight and two PCN species (Globodera pallida and G. rostochiensis) were recorded for three and two consecutive years, respectively. The potato panel was genotyped using genotyping by sequencing (GBS), and 1,20,622 SNP markers were identified. A total of 7 SNP associations for late blight resistance, 9 and 11 for G. pallida and G. rostochiensis, respectively, were detected by additive and simplex dominance models of GWAS. The associated SNPs were distributed across the chromosomes, but most of the associations were found on chromosomes 5, 10 and 11, which have been earlier reported as the hotspots of disease-resistance genes. The GS prediction accuracy estimates were low to moderate for resistance to G. pallida (0.04-0.14) and G. rostochiensis (0.14-0.21), while late blight resistance showed a high prediction accuracy of 0.42-0.51. This study provides information on the complex genetic nature of these biotic stress traits in potatoes and putative SNP markers for resistance breeding.

Admixture mapping and selection scans identify genomic regions associated with stomatal patterning and disease resistance in hybrid poplars.

Variation in fitness components can be linked in some cases to variation in key traits. Metric traits that lie at the intersection of development, defense, and ecological interactions may be expected to experience environmental selection, informing our understanding of evolutionary and ecological processes. Here, we use quantitative genetic and population genomic methods to investigate disease dynamics in hybrid and non-hybrid populations. We focus our investigation on morphological and ecophysiological traits which inform our understanding of physiology, growth, and defense against a pathogen. In particular, we investigate stomata, microscopic pores on the surface of a leaf that regulate gas exchange during photosynthesis and are sites of entry for various plant pathogens. Stomatal patterning traits were highly predictive of disease risk. Admixture mapping identified a polygenic basis of disease resistance. Candidate genes for stomatal and disease resistance map to the same genomic regions and experienced positive selection. Genes with functions to guard cell homeostasis, the plant immune system, components of constitutive defenses, and growth-related transcription factors were identified. Our results indicate positive selection acted on candidate genes for stomatal patterning and disease resistance, potentially acting in concert to structure their variation in naturally formed backcrossing hybrid populations.

Investigation of Groundwater Potential Zone Using Geophysical and Geospatial Technology in Akuku-Toru Local Government Area, Rivers State, Nigeria

Background of the Study: The study area is located within four communities in Akuku-Toru Local Government Area, which is a coastal region within the Niger Delta. The study area is heavily reliant on groundwater for domestic, industrial, and agricultural purposes. The hydrogeological dynamics of the area are complex, with diverse geological formations and intricate subsurface structures. As a result, an innovative and integrated approach is necessary for effective groundwater management. The study investigated the potential of groundwater resources in the study area and identification of fresh water zones using electrical resistivity, remote sensing, and GIS which employs geophysical surveys, remote sensing techniques, and geospatial analysis to explore the interplay between aquifer characteristics, geological formations, and topographical attributes. The fresh water zones are regions with low saline content.&#x0D; Aim: This study aims to assess groundwater potential in some parts of Akuku-Toru Local Government Area by integrating the geophysical data from Vertical Electrical Sounding (VES) surveys with geospatial analysis from GIS and Remote Sensing Technology. The research seeks to provide a comprehensive understanding of groundwater availability and its correlation with geophysical and geospatial parameters.&#x0D; Study Design: A thorough methodology was employed to investigate the possibility of freshwater resources in the study area. The approach involved gathering Vertical Electrical Sounding (VES) data from 8 locations, as well as incorporating geospatial data such as elevation, drainage density, geology, apparent resistivity, and slope maps. The collected data underwent rigorous processing, correlation analysis, and reclassification to explore the potential of freshwater resources in the study area.&#x0D; Place and Duration of the Study: The research was conducted in four communities (Abonnema, Ekulama, Jacobkiri and Belema) within the Akuku-Toru Local Government Area over a span of 18months. The area's hydrogeological context and topographical features are investigated to determine groundwater potential zones.&#x0D; Methods: The research utilized the Vertical Electrical Sounding (VES) method to obtain aquifer resistivity data, reflecting subsurface Lithological variations. Geospatial analysis involved accessing elevation and drainage density patterns. Correlation analysis was also performed to link the geophysical and geospatial data with qualitative interpretations, facilitating the assignment of numerical values representing groundwater potential zones.&#x0D; Results: The Correlation analysis revealed insightful patterns. Aquifer resistivity, elevation and slope were identified as influential parameter affecting groundwater potential. The geology of the study area, categorized into dominant formations, exhibited varying degrees of potential for freshwater resources. The Correlation of geophysical and geospatial data provided a comprehensive understanding of groundwater availability across the study region.&#x0D; Conclusion: The integration of geophysical and geospatial analysis offers a robust approach to groundwater potential assessment. The research findings contributed to valuable insights into the spatial distribution of potential freshwater resources in the study area. The correlation between aquifer resistivity, elevation, slope, and geology enhanced our understanding of hydrological conditions and provides a foundation for future groundwater studies and management strategies.

Integration of Seismic Poisson Impedance Data with Real-Time Geomechanics and Real-Time 3D Ultradeep Resistivity Inversion Enabled New Opportunities in Developed Field: Case Study from Kuwait

Summary The Wara sandstone reservoir in the Minagish field of Kuwait Oil Company is a complex deposition of a typical pro-deltaic environment consisting of shaly-silty sandstone sequences, referenced as W7–W1. Three of these sequences (W6, W5, and W3) were expected in the case study well. The objective was to set a 9⅝-in. casing at the top of W6 and then drill through the Wara sequences to connect all of them and land and drill the lateral section within W3. The W6 sequence is typically the primary target in the Wara formation, being thick and consistent throughout the field. The next logical step in developing the Wara reservoir was to study and investigate the minor W5 and W3 members. Due to poor correlation of W5 and W3 channels in offset wells, the geological target was selected based on seismic Poisson impedance (PI). Historically, targeting the Wara formation occasionally resulted in multiple sidetracks due to drilling challenges. A real-time geomechanics service was used to overcome drilling challenges, and real-time 3D ultradeep resistivity inversion was implemented to optimize the well placement. An extensive predrilling study for geomechanical and ultradeep resistivity inversion modeling helped to develop a road map for an optimal and safe well-construction process. The study showed that use of real-time 3D ultradeep azimuthal resistivity (UDAR) inversion would help to optimize the well placement and maximize the sweet-zone exposure. The original well design, mud properties, and drilling parameters were modified based on the geomechanical study. Additionally, real-time geomechanics services were used to monitor and control the drilling process to follow the road map, which helped to avoid drilling issues, geostop at the W6 channel, and finally to run the casing smoothly. Real-time 3D ultradeep resistivity mapping in the lateral section helped the operator to drill through W6 and W5, land precisely, and drill the lateral in the W3 channel, which was well developed, as expected from seismic PI analysis. Formation evaluation of the lateral section showed an average porosity of 24 p.u., water saturation of 11%, and up to 3 darcies/cp mobility. The application of real-time 3D ultradeep resistivity inversion helped to triple the planned formation exposure and discover a geometric extension of the above deposited channels (W6 and W5), which will help for future field development. The flow test showed the highest production rates from W3 in the field. The integrated approach described above was recommended to be utilized for all future Wara wells.

QTL mapping of adult-plant resistance to leaf and stripe rust in wheat cross L224-3/Zhengzhou5389

QTL mapping of adult-plant resistance to leaf and stripe rust in wheat cross L224-3/Zhengzhou5389

The human fungal pathogen Aspergillus fumigatus can produce the highest known number of meiotic crossovers.

Sexual reproduction involving meiosis is essential in most eukaryotes. This produces offspring with novel genotypes, both by segregation of parental chromosomes as well as crossovers between homologous chromosomes. A sexual cycle for the opportunistic human pathogenic fungus Aspergillus fumigatus is known, but the genetic consequences of meiosis have remained unknown. Among other Aspergilli, it is known that A. flavus has a moderately high recombination rate with an average of 4.2 crossovers per chromosome pair, whereas A. nidulans has in contrast a higher rate with 9.3 crossovers per chromosome pair. Here, we show in a cross between A. fumigatus strains that they produce an average of 29.9 crossovers per chromosome pair and large variation in total map length across additional strain crosses. This rate of crossovers per chromosome is more than twice that seen for any known organism, which we discuss in relation to other genetic model systems. We validate this high rate of crossovers through mapping of resistance to the laboratory antifungal acriflavine by using standing variation in an undescribed ABC efflux transporter. We then demonstrate that this rate of crossovers is sufficient to produce one of the common multidrug resistant haplotypes found in the cyp51A gene (TR34/L98H) in crosses among parents harboring either of 2 nearby genetic variants, possibly explaining the early spread of such haplotypes. Our results suggest that genomic studies in this species should reassess common assumptions about linkage between genetic regions. The finding of an unparalleled crossover rate in A. fumigatus provides opportunities to understand why these rates are not generally higher in other eukaryotes.

Genome-wide QTL mapping for stripe rust resistance in spring wheat line PI 660122 using the Wheat 15K SNP array.

Stripe rust is a global disease of wheat. Identification of new resistance genes is key to developing and growing resistant varieties for control of the disease. Wheat line PI 660122 has exhibited a high level of stripe rust resistance for over a decade. However, the genetics of stripe rust resistance in this line has not been studied. A set of 239 recombinant inbred lines (RILs) was developed from a cross between PI 660122 and an elite Chinese cultivar Zhengmai 9023. The RIL population was phenotyped for stripe rust response in three field environments and genotyped with the Wheat 15K single-nucleotide polymorphism (SNP) array. A total of nine quantitative trait loci (QTLs) for stripe rust resistance were mapped to chromosomes 1B (one QTL), 2B (one QTL), 4B (two QTLs), 4D (two QTLs), 6A (one QTL), 6D (one QTL), and 7D (one QTL), of which seven QTLs were stable and designated as QYrPI660122.swust-4BS, QYrPI660122.swust-4BL, QYrPI660122.swust-4DS, QYrPI660122.swust-4DL, QYrZM9023.swust-6AS, QYrZM9023.swust-6DS, and QYrPI660122.swust-7DS. QYrPI660122.swust-4DS was a major all-stage resistance QTL explaining the highest percentage (10.67%-20.97%) of the total phenotypic variation and was mapped to a 12.15-cM interval flanked by SNP markers AX-110046962 and AX-111093894 on chromosome 4DS. The QTL and their linked SNP markers in this study can be used in wheat breeding to improve resistance to stripe rust. In addition, 26 lines were selected based on stripe rust resistance and agronomic traits in the field for further selection and release of new cultivars.

Solid Oxide Cell Performance: Spatially Resolved Oxygen Electrode Stability

Solid Oxide Cell (SOC) electrolysis will play an important role in the electrification of the chemical, fertilizer, and fuel industries, contributing to the reduction of their reliance on fossil fuel feedstocks. The integration of high temperature steam and CO2-electrolyzers in industrial processes with readily available waste heat and renewable electricity allows for highly efficient green hydrogen production and methods for CO2 utilization.The development of next generation SOC electrolyzer technology at TNO aims to provide high performance and low-cost technological options for the electrification of the aforementioned chemicals and fuels industries. The ambition of the SOC technology development program is to assist the whole value chain, from cell manufacturing to end-users, by increasing the economic viability of the technology. In line with this ambition, the TNO R&D activities regarding SOC technology concentrate on cell and stack technology development coupled with techno-economic and business case studies on SOC technology integration in the industrial environment. Improvements in SOC performance and durability for electrolysis applications are of great importance for the successful industrial implementation of the technology. Hydrogen Europe targets for 2030 aim at low stack degradation rates of 0.5%/khr at thermoneutral voltage, while delivering current densities of at least 1.5 A/cm2. Therefore, lifetime improvements at high current density are one of the vocal points of SOC development efforts, which calls for a good understanding of the degradation phenomena and analytical methods to investigate the material stability in the SOC during electrolysis operation.In this contribution, the current status of SOC development and testing within TNO will be presented. Several aspects of TNO SOC performance characteristics will be discussed, with a focus on water electrolysis performance and lifetime behaviour during endurance tests of several thousand hours. Excellent water electrolysis performance of the TNO SOC cells is observed at thermoneutral voltage (1.3 V), achieving current density values of 1.75 A/cm2 at an operating temperature of 750 ºC. Lifetime assessment and material degradation of the SOC will be discussed, with a focus on the analysis of observed degradation phenomena in the oxygen electrode material. As oxygen electrode degradation can be critical for SOC performance in a stack environment, it is important to have a good understanding of the degradation processes and the ability to monitor them. At TNO, a novel high-resolution 2D mapping of the lateral conductivity of the oxygen electrode have been used as an effective tool for quality control and validation of the air electrode development. Additionally, the combination of 2D sheet resistance mapping, SEM-EDX and XRD techniques (Figure 1) provides a powerful combination of tools to obtain a spatially resolved (3D) view of the localized degradation observed in the oxygen electrode after several thousand hours of water electrolysis. Figure 1

Partial Discharge-Originated Deterioration of Insulating Material Investigated by Surface-Resistance and Potential Mapping

The endurance of medium- and high-voltage electrical insulation is a key reliability element in a broad spectrum of applications that cover transmission and distribution levels, the transportation segment, the industrial environment, and power electronics-based energy-conversion systems. The high electric-field stress and high-frequency switching phenomena as well as the impact of environmental conditions lead to the occurrence of partial discharges (PD) and the subsequent deterioration of electrical insulation. Partial discharges usually occur inside solid insulation materials in tiny voids that may either be located adjacent to the electrodes or in the bulk of dielectric material. This effect refers to both AC and DC systems; however, AC voltage is usually much more intensive as compared to DC voltage. This paper describes a novel combined approach based on surface-resistance and potential mapping to reveal the effects of internal processes and the deterioration of insulating material due to the actions of partial discharges. To realize the research objective, the following two-step approach was proposed. Multi-point resistance mapping enables us to identify the spots of discharge channels, manifesting a-few-orders-of-magnitude-lower surface resistance as compared to untreated areas. In addition, surface-potential mapping that was stimulated by corona-charge deposition reflects quasi-equipotential clusters and the related polarity-dependent dynamics of charge decay. A high spatial and temporal resolution allows for the precise mapping and tracing of decay patterns. Experiments were carried out on polyethylene (PE) and Nomex specimens that contained embedded voids. During PD events, the effective discharge areas are identified along with the memory effects that originate from the accumulation of surface charges. Long-term aging processes may drive the formation of channels that are initiated from the deteriorated micro clusters, in turn, penetrating the bulk isolation. The presented methodology and experimental results extend the insight into PD mechanisms and internal surface processes.

Development of novel wheat-rye 6RS small fragment translocation lines with powdery mildew resistance and physical mapping of the resistance gene PmW6RS.

Novel wheat-rye 6RS small fragment translocation lines with powdery mildew resistance were developed, and the resistance gene PmW6RS was physically mapped onto 6RS-0.58-0.66-bin corresponding to 18.38Mb in Weining rye. Rye (Secale cereale L., RR) contains valuable genes for wheat improvement. However, most of the rye resistance genes have not been successfully used in wheat cultivars. Identification of new rye resistance genes and transfer of these genes to wheat by developing small fragment translocation lines will make these genes more usable for wheat breeding. In this study, a broad-spectrum powdery mildew resistance gene PmW6RS was localized on rye chromosome arm 6RS using a new set of wheat-rye disomic and telosomic addition lines. To further study and use PmW6RS, 164 wheat-rye 6RS translocation lines were developed by 60Coγ-ray irradiation. Seedling and adult stage powdery mildew resistance analysis showed that 106 of the translocation lines were resistant. A physical map of 6RS was constructed using the 6RS translocation and deletion lines, and PmW6RS was localized in the 6RS-0.58-0.66-bin, flanked by markers X6RS-3 and X6RS-10 corresponding to the physical interval of 50.23-68.61Mb in Weining rye genome. A total of 23 resistance-related genes were annotated. Nine markers co-segregate with the 6RS-0.58-0.66-bin, which can be used to rapidly trace the 6RS fragment carrying PmW6RS. Small fragment translocation lines with powdery mildew resistance were backcrossed with wheat cultivars, and 39 agronomically acceptable homozygous 6RS small fragment translocation lines were obtained. In conclusion, this study not only provides novel gene source and germplasms for wheat resistance breeding, but also laid a solid foundation for cloning of PmW6RS.

Genome-wide association mapping of rust resistance in Aegilops longissima.

The rust diseases, including leaf rust caused by Puccinia triticina (Pt), stem rust caused by P. graminis f. sp. tritici (Pgt), and stripe rust caused by P. striiformis f. sp. tritici (Pst), are major limiting factors in wheat production worldwide. Identification of novel sources of rust resistance genes is key to developing cultivars resistant to rapidly evolving pathogen populations. Aegilops longissima is a diploid wild grass native to the Levant and closely related to the modern bread wheat D subgenome. To explore resistance genes in the species, we evaluated a large panel of Ae. longissima for resistance to several races of Pt, Pgt, and Pst, and conducted a genome-wide association study (GWAS) to map rust resistance loci in the species. A panel of 404 Ae. longissima accessions, mostly collected from Israel, were screened for seedling-stage resistance to four races of Pt, four races of Pgt, and three races of Pst. Out of the 404 accessions screened, two were found that were resistant to all 11 races of the three rust pathogens screened. The percentage of all accessions screened that were resistant to a given rust pathogen race ranged from 18.5% to 99.7%. Genotyping-by-sequencing (GBS) was performed on 381 accessions of the Ae. longissima panel, wherein 125,343 single nucleotide polymorphisms (SNPs) were obtained after alignment to the Ae. longissima reference genome assembly and quality control filtering. Genetic diversity analysis revealed the presence of two distinct subpopulations, which followed a geographic pattern of a northern and a southern subpopulation. Association mapping was performed in the genotyped portion of the collection (n = 381) and in each subpopulation (n = 204 and 174) independently via a single-locus mixed-linear model, and two multi-locus models, FarmCPU, and BLINK. A large number (195) of markers were significantly associated with resistance to at least one of 10 rust pathogen races evaluated, nine of which are key candidate markers for further investigation due to their detection via multiple models and/or their association with resistance to more than one pathogen race. The novel resistance loci identified will provide additional diversity available for use in wheat breeding.

The Proximal Ejecta Around the Marine‐Target Lockne Impact Structure, Sweden

AbstractVery few impact craters on Earth have preserved proximal ejecta (ejecta blanket), which when present help us to better understand the cratering processes when asteroid hits Earth. The 458 Ma old Lockne impact structure consists of a 7.5‐km wide nested crater in the crystalline basement surrounded by an approximately 3‐km wide brim developed in the upper sedimentary target. The asteroid struck a marine environment with 500 m sea water, 50‐m lithified limestone, and 30 m of Cambrian clay covering a peneplainized crystalline basement. The transient crater that developed in rock and water obtained a “soup‐plate” shape and reached about 7 km from the impact crater center, the farthest on the down‐range side. The brim of the soup‐plate was partially stripped of Ordovician limestone and water before the emplacement of inner impact crater ejecta. Most of the ejecta rest upon the Cambrian clay (today shale). The asteroid struck obliquely from the east, which is reflected in the ejecta distribution. The proximal ejecta field is divided into two crescent‐shaped areas to the northwest and southwest of the nested crater and covers 26 km2. Resistivity profiles, mapping, and core drilling show that the thickness of the ejecta masses range between 30 and 50 m with a total volume of about 1 km3. They were not re‐worked by the resurge. They represent roughly 26 vol% of the calculated excavated volume of crystalline rocks. Thus, it can be concluded that the Lockne impact crater has a well‐preserved ejecta blanket.

Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection.

The online version contains supplementary material available at 10.1007/s11032-023-01400-5.

Genome-wide phage susceptibility analysis in Acinetobacter baumannii reveals capsule modulation strategies that determine phage infectivity.

Phage have gained renewed interest as an adjunctive treatment for life-threatening infections with the resistant nosocomial pathogen Acinetobacter baumannii. Our understanding of how A. baumannii defends against phage remains limited, although this information could lead to improved antimicrobial therapies. To address this problem, we identified genome-wide determinants of phage susceptibility in A. baumannii using Tn-seq. These studies focused on the lytic phage Loki, which targets Acinetobacter by unknown mechanisms. We identified 41 candidate loci that increase susceptibility to Loki when disrupted, and 10 that decrease susceptibility. Combined with spontaneous resistance mapping, our results support the model that Loki uses the K3 capsule as an essential receptor, and that capsule modulation provides A. baumannii with strategies to control vulnerability to phage. A key center of this control is transcriptional regulation of capsule synthesis and phage virulence by the global regulator BfmRS. Mutations hyperactivating BfmRS simultaneously increase capsule levels, Loki adsorption, Loki replication, and host killing, while BfmRS-inactivating mutations have the opposite effect, reducing capsule and blocking Loki infection. We identified novel BfmRS-activating mutations, including knockouts of a T2 RNase protein and the disulfide formation enzyme DsbA, that hypersensitize bacteria to phage challenge. We further found that mutation of a glycosyltransferase known to alter capsule structure and bacterial virulence can also cause complete phage resistance. Finally, additional factors including lipooligosaccharide and Lon protease act independently of capsule modulation to interfere with Loki infection. This work demonstrates that regulatory and structural modulation of capsule, known to alter A. baumannii virulence, is also a major determinant of susceptibility to phage.

Geophysical Mapping by Electromagnetic Induction of Gold Occurrences in Birimian Formations of Liptako: Case of Sorbon Haoussa Sector (Souhwest Niger)

The survey zone corresponds to the Sirba greenstone belt, one of Liptako Birimian Formations (LBF) of Niger. Previous aeromagnetic and geochemical works reveal the significant gold occurrences. The present study integrates geophysical mapping of these occurrences by electromagnetic induction on field. A multi-frequencies system of 10 frequencies was used for depth and subsurface investigation of resistive anomalies. The interpretation of obtained results shown two types of resistive anomalies, corresponding to the conductive units: deep anomalies obtained with low frequencies and subsurface anomalies detected with high frequencies. The subsurface anomalies were detected around the 15 meters and the deep anomalies were recorded beyond 80 meters. All of the detected resistive anomalies are in a lenticulars shapes oriented N-S or E-W. The analysis of combined resistivity map from all frequencies shown three zones of resistive anomaly presenting a high potential in conductive metals: The first zone Z1 (most important), located in Eastern studied zone covering, covering a surface of 3.5 Km2, the second zone Z2 is located in West and covers an area of 2.9 Km2 and the third anomaly zone Z3 is located in South with a surface of 0.96 Km2. On field, these conductive units correspond to auriferous quartz veins and/or highly altered manganese schists, exploited by using the artisanal mining wells, up to 20 meters in depth.

Weed resistance assessment through airborne multimodal data fusion and deep learning: A novel approach towards sustainable agriculture

Herbicide-resistant weeds represent a significant challenge to modern agriculture. The need for innovative and sustainable weed management strategies has become increasingly pressing as the threat of herbicide-resistant weeds continues to escalate. Unmanned aerial vehicles (UAVs) and various sensors have become indispensable tools in plant phenotyping studies. In this study, a comprehensive resistance score (CRS) was proposed to effectively quantify weed resistance in the field. Multimodal data fusion and deep learning were utilized to perform regression of CRS, three different fusion methods for 3D-CNN and 2D-CNN to extract and fuse multimodal information collected by UAVs including spectral, structural, and texture information for weed resistance. Our findings demonstrate that (1) discernible differences in spectral response exist between susceptible and resistant weeds, with the optimal band for the Successive Projections Algorithm (SPA) selection coinciding with the optimal band for resistance expression band; (2) resistance assessment accuracy is enhanced through multimodal data fusion, with the late deep fusion network exhibiting the best accuracy, R2 of 0.777 and RMSE of 0.547; (3) the multimodal fusion network model displays robust adaptability in resistance assessment across varying densities and effectively generates weed resistance map. Overall, this research demonstrates the effectiveness of using multimodal data fusion and CRS, combined with deep learning for achieving accurate and reliable weed resistance assessment in agricultural fields.