Moderate Resistance Research Articles

Determination of insecticide resistance in cotton whitefly in north India

The whitefly, Bemisia tabaci (Gennadius) considered as most destructive pest, poses a significant threat to various crop species globally has developed resistance due to the indiscriminate use of synthetic chemicals. A study was carried out in 2018 at ICAR-Indian Agricultural Research Institute, New Delhi to determine insecticide resistance, in five Asia II 1 populations of B. tabaci from different cotton (Gossypium hirsutum L.) growing regions of north India. The susceptibility of the populations to different insecticide classes, viz. synthetic pyrethroid (cypermethrin); neonicotinoids (imidacloprid and thiamethoxam); thiourea (diafenthiuron) and diamide (cyantraniliprole) were assessed. Results revealed substantial heterogeneity in the responses of these populations to the insecticides. Sriganganagar and Bathinda populations exhibited moderate resistance to cypermethrin, imidacloprid, and thiamethoxam. Low level of resistance was observed in Bathinda and Sriganganagar populations against diafenthiuron. All populations were highly susceptible to cyantraniliprole. No cross-resistance was observed between cyantraniliprole and other insecticides, suggesting its potential as an alternative for managing insecticide resistance. High levels of detoxification enzymes (esterase, cytochrome P450 monooxygenase, and glutathione-S-transferase) in Sriganganagar and Bathinda populations indicated a positive correlation between insecticide resistance and detoxifying enzymes. These findings offer valuable insight for implementing insecticide rotation strategies to combat B. tabaci resistance in India.

Structure and function of Achilles and patellar tendons following moderate slow resistance training in young and old men.

The aim of this study was to investigate the effect of aging and resistance training with a moderate load on the size and mechanical properties of the patellar (PT) and Achilles tendon (AT) and their associated aponeuroses; medial gastrocnemius (MG) and vastus lateralis (VL). Young (Y55; 24.8 ± 3.8yrs, n = 11) and old men (O55; 70.0 ± 4.6yrs, n = 13) were assigned to undergo a training program (12weeks; 3 times/week) of moderate slow resistance training [55% of one repetition maximum (RM)] of the triceps surae and quadriceps muscles. Tendon dimensions were assessed using 1.5T magnetic resonance imaging before and after 12weeks. AT and PT cross sectional area (CSA) were determined every 10% of tendon length. Mechanical properties of the free AT, MG aponeurosis, PT, and VL aponeurosis were assessed using ultrasonography (deformation) and tendon force measurements. CSA of the AT but not PT was greater in O55 compared with Y55. At baseline, mechanical properties were generally lower in O55 than Y55 for AT, MG aponeurosis and VL aponeurosis (Young's modulus) but not for PT. CSA of the AT and PT increased equally in both groups following training. Further, for a given force, stiffness and Young's modulus also increased equally for VL aponeurosis and AT, for boths groups. The present study highlights that except for the PT, older men have lower tendon (AT, MG aponeurosis, and VL aponeurosis) mechanical properties than young men and 12-weeks of moderate slow resistance training appears sufficient to improve tendon size and mechanical adaptations in both young and older men. New and Noteworthy: These novel findings suggest that short-term moderate slow resistance training induces equal improvements in tendon size and mechanics regardless of age.

Allele mining for blast-resistance gene at Pi5 locus in rice

Rice plays a crucial role in global food security, serving as a staple for more than half of the world's population. Rice blast, caused by the fungus Magnaporthe oryzae, is one of the most devastating fungal diseases, resulting in substantial economic losses in terms of rice yield and grain quality. The resistance provided by individual blast resistance genes tends to become ineffective within a few years of extensive agricultural use due to the rapid evolution of the fungus. Therefore, continuous efforts in resistance breeding in rice are required to enrich the pool of new resistance genes and alleles. A large-scale screening of new blast resistance alleles was conducted across 2000 rice accessions from major rice-producing areas in China. Field trials were employed in two rice uniform blast nurseries located in Enshi and Yichang. Approximately 153 rice accessions showed at least moderate resistance to the rice blast. Sequence-based allele mining was used to identify the allelic variants of major rice blast resistance genes at the Pi5 locus of chromosome 9. Six novel alleles were identified from 64 accessions. Field tests at five locations, including Enshi, Yichang, Lvtian, Taojiang, and Yaan, and greenhouse inoculation using 33 blast strains from Hubei, Hunan, Guangzhou, and Sichuan, were employed to verify the resistance of these six alleles. Three near-isogenic lines (types 2, 4, and 6) were constructed and inoculated with 31 blast isolates from Heilongjiang to evaluate their blast resistance. Furthermore, bulk segregant analysis was used to confirm that Pi5-type2 and Pi5-type6 are dominant alleles in the analyzed populations. These novel alleles expand the allelic series, enriching the genetic resources for rice blast resistance breeding programs, especially in the north of China. Furthermore, they provide valuable insights into the molecular interactions between rice and rice blast.

Field Evaluation of Experimental Maize Hybrids for Resistance to the Fall Armyworm (Lepidoptera: Noctuidae) in a Warm Temperate Climate.

The polyphagous fall armyworm (FAW), Spodoptera frugiperda, has become an invasive pest worldwide in recent years. To develop maize germplasm with multiple pest resistance and understand genetic inheritance, 12 experimental hybrids (six pairs of reciprocal crosses) with diverse genetic backgrounds and four commercial checks were examined for FAW resistance in 2013 and 2014. The experiment utilized a randomized complete block design with four replications as the block factor. FAW injury on maize plants was assessed at 7 and 14 d after the artificial infestation at the V6 stage, and predatory arthropod taxa and abundance on maize seedlings were recorded 7 d after the infestation. Spodoptera frugiperda resistance varied significantly among the 16 hybrids. Two reciprocal crosses ('FAW1430' × 'Oh43' and 'CML333' × 'NC358') showed the least FAW injury. Eleven arthropod predators [i.e., six coleopterans, three hemipterans, earwigs (dermapterans), and spiders (or arachnids)] were also recorded; the two most common predators were the pink spotted ladybeetle, Coleomegilla maculata, and the insidious flower (or minute pirate) bug, Orius spp. Predator abundance was not correlated to FAW injury but varied greatly between 2013 and 2014. Principal component analysis demonstrated that, when compared with FAW resistant (or Bt-transgenic) checks ('DKC69-71', 'DKC67-88', and 'P31P42'), five pairs of the reciprocal crosses had moderate FAW resistance, whereas a pair of reciprocal crosses ('NC350' × 'NC358' and NC358 × NC350) showed the same FAW susceptibility as the non-Bt susceptible check 'DKC69-72'. Both parents contributed similarly to FAW resistance, or no maternal/cytoplasmic effect was detected in the experimental hybrids.

Cardiopulmonary rehabilitation’s influence on cognitive functions, psychological state, and sleep quality in long COVID-19 patients: A randomized controlled trial

ABSTRACT Background: Cognitive impairment, brain fog, depressive symptoms, and sleep disturbance are prevalent symptoms among individuals with long COVID, for which there currently is no treatment. Aim: To assess the effectiveness of an eight-week cardiopulmonary rehabilitation programme on cognition, psychological well-being, and sleep quality in individuals with long COVID-19. Methods: Forty participants diagnosed with long COVID-19 (26 female, 14 male participants; mean age 53 ± 11 years) were randomly assigned to a rehabilitation group or to a control group. The control group maintained their regular daily habits, while the rehabilitation group was prescribed an individualized clinical programme consisting of three sessions per week. Each session involved light to moderate aerobic exercise, resistance training, and respiratory exercises. Neuropsychological tests evaluating executive function, memory, and processing speed were administered at baseline and at study completion. Participants also completed questionnaires on their psychological state and sleep quality at both time points. Results: No difference between groups was observed for neuropsychological test performance, however significant group differences in perceived stress and depression were found post-intervention. Conclusion: Cardiopulmonary rehabilitation was shown to be effective in individuals suffering from long COVID in terms of decreasing perceived stress and depression levels but not for neuropsychological test performance. ClinicalTrials.gov NCT05035628. Trial registration: ClinicalTrials.gov identifier: NCT05035628..

Registration of ‘CP 13‐1954’ sugarcane for Florida organic soils

Abstract‘CP 13‐1954’ (Reg. no. CV‐218, PI 704104) sugarcane (Saccharum spp. hybrid) was developed through cooperative research conducted by the USDA–ARS, the University of Florida, and the Florida Sugar Cane League, Inc., and released to growers for organic (muck) soils in Florida in June 2020. The parentage of CP 13‐1954 is ‘CP 85‐1491’ × Poly 09‐24. Based on the results of three crops (plant cane, first ratoon, and second ratoon) in field trials conducted at five locations, CP 13‐1954 had higher cane yield (16.2%), sucrose yield (15.6%), and economic index (29.7%) at P < .05 compared with the reference cultivar, ‘CP 96‐1252’. CP 13‐1954 stalks are usually taller than the reference cultivar, ‘CP 00‐1101’, with small‐to‐medium diameter, and exhibits resistance to ratoon stunting disease, Sugarcane mosaic virus strain E, brown rust, orange rust, and smut and moderate resistance to leaf scald on muck soils in Florida. CP 13‐1954 has Bru1 locus that provides resistance against brown rust. CP 13‐1954 showed moderate cold tolerance among all the tested cultivars.

Identification of Fusarium wilt resistant genotypes in lentil

Identification of Fusarium wilt resistant genotypes in lentil

Unveiling the High Prevalence of Antibiotic Resistance and Quorum Sensing Genes in Uropathogenic <i>Escherichia coli</i>

Escherichia coli is considered one of the uropathogenic bacteria with different infection symptoms representing mild illness to acute sepsis. This study aims to detect E. coli in patients with urinary infection and investigate quorum sensing genes (lux S and motA) in multi-drug resistant isolates of E. coli. 200 urine samples were collected from patients with urinary tract infections from several hospitals in Baghdad. The antibiotics sensitivity test showed high resistance of isolates for Ampicillin (100%), Cefazolin (97%), Trimethoprim/ Sulfamethoxazole (83%), Ceftriaxone (77%), Ceftazidime and Ciprofloxacin (70% each of them), and moderate resistance of isolates for Levofloxacin (50%), Gentamicin (47%), Cefepime (40%), while low resistance Piperacillin/ Tazobactam (33%), Cefoxitin (30%), Nitrofurantoin (17%), Imipenem (10%), Ertapenem and Amikacin (7% each of them), and Tigecycline (3%). The results showed an increase percentage of infection in females was 30% in the ages 30-44 years, whereas in ages 15-29 and more than 45 years was 17%. There was a high percentage (57.11%) of resistant isolates in females which are ages 30-44 years. While the ages more than 45 years were 66.4% and ages 15-29 were 34%. While, in males, the percentage was high in ages more than 45 years (35.25%) followed by age groups 30-44 years (31.5%) and 15-29 years (31%). The prevalence percentage for luxS and motA genes in E. coli was 100%. In conclusion, E. coli isolates were multi-drug resistant due to all isolates had quorum sensing genes. Moreover, uropathogenic of E. coli in females was more frequent than in males due to the resistance of bacteria to antibiotics.

Diagnostic conversion to bipolar disorder among adolescents and young adults with major depressive disorder: a nationwide longitudinal study.

Although several studies have examined a diagnostic conversion from major depressive disorder (MDD) to bipolar disorder (BD), only a few studies specifically focused on adolescents and young adults who are at the peak ages of BD onset. Data from participants (N = 130,793) aged 10-29years who were diagnosed with MDD were extracted from the Taiwan National Health Insurance Research Database. We applied demographic analyses, survival analysis, Aalen Johansen curves, and Cox regression, investigating the diagnostic conversion rate and factors that were most or less predictive of conversion. Among the adolescents and young adults with MDD, the number of participant conversion subsample is 14,187 and the conversion rate was 13.80% (95% confidence interval: 13.54-14.06%) during the 11-year follow-up. The conversion rate was highest in the first year (4.50%; 4.39-4.61%) and decreased over time. The significant predictors were younger age of diagnosis with MDD (p < 0.001), moderate and high antidepressant resistance (p < 0.001), obesity (p < 0.001), psychiatric comorbidities (attention-deficit/hyperactivity disorder, substance use disorder, and cluster B and C personality disorder, all p < 0.001), a family history of mental disorders (schizophrenia and mood disorders, all p < 0.05), lower monthly income (p < 0.001), and more mental health visits to the clinic each year (p < 0.001). A composite of demographic characteristics, antidepressant resistance, physical and psychiatric comorbidities, and family history significantly predicted diagnostic conversion from MDD to BD (area under the curve = 0.795, p < 0.001). Compared to adult population, the adolescents and young adults had different factors that were most or less predictive of conversion, which warrants further investigation.

Comparison of different screening methods for the selection of Ascochyta blight disease on chickpea (Cicer arietinum L.) genotypes.

Chickpea (Cicer arietinum L.) is the second most important edible food grain legume, widely grown all over the world. However, the cultivation and production of chickpea are mainly affected by the Ascochyta blight (AB) disease, which causes losses of up to 100% in areas with high humidity and warm temperature conditions. Various screening methods are used in the selection of chickpea genotypes for resistance to AB disease. These methods are natural field condition (NFC), artificial epidemic field condition (AEC), marker-assisted selection (MAS), and real-time PCR (RT-PCR). The study was conducted with 88 chickpea test genotypes between the 2014 and 2016 growing seasons. The results of the screening were used to sort the genotypes into three categories: susceptible (S), moderately resistant (MR), and resistant (R). Using MAS screening, 13, 21, and 54 chickpea genotypes were identified as S, MR, and R, respectively. For RT-PCR screening, 39 genotypes were S, 31 genotypes were MR, and 18 genotypes were R. In the AEC method for NFC screening, 7, 17, and 64 genotypes were S, MR, and R, while 74 and 6 genotypes were S and MR, and 8 genotypes were R-AB disease. As a result of screening chickpea genotypes for AB disease, it was determined that the most effective method was artificial inoculation (AEC) under field conditions. In the study, Azkan, ICC3996, Tüb-19, and Tüb-82 were determined as resistant within all methods for Pathotype 1.

Near surface resistivity investigation of regolith of Middle Benue Trough: implications on road pavement along Lafia-Shendam Axis, North Central Nigeria

ABSTRACT Electrical characteristics and subsurface structures associated with the regolith of Middle Benue Trough have been investigated. Vertical electrical sounding (VES) and constant separation traversing (CST) techniques were employed for data acquisition along Lafia-Shendam Road, Lafia, North Central Nigeria. Forty (40) Schlumberger sounding stations and four (4) Wenner resistivity profiles were occupied along opposite sides of the road to delineate and decipher the subsurface geological structures. Second-order Dar Zarrouk parameters (longitudinal and transverse resistivities, mean resistivity and coefficient of anisotropy) computed from VES parameters were also used to evaluate the pseudo-anisotropy characteristics of the regolith cover. Geoelectric sequences delineated within the study area include thin topsoil, alluvium deposit, weathered layer (laterite and saprolite) and fresh basement. The regolith is hosted by a weathered sedimentary rock at an average depth which varies from 10.2 to 37.3 m. The regolith structure is not complex and has a greater proportion of conductive laterite. The saprolite associated with the host sedimentary rock, masked in the VES technique, is revealed as a very thin zone with moderate resistivity in the CST 2-D structures. The predominance of laterite in the regolith is also corroborated by the range of values of the coefficient of anisotropy and mean resistivity.

Synthesis and Characterization of Bisphenol-C Epoxy Crotonate and Its Fiber-Reinforced Composites

Bisphenol-C epoxy crotonate resin was synthesized by reacting 8.09g epoxy resin of bisphenol- C, and 2.15g crotonic acid using 25 mL 1,4-dioxane as a solvent, and 1 mL triethylamine as a catalyst at reflux temperature for 1-6 h. Solid epoxy crotonate (ECCR) is highly soluble in common organic solvents. ECCR was characterized by its acid (24.5-1.5 mg KOH/g) and hydroxyl (504.5-678.4 mg KOH/g) values. The structure of ECCR is supported by FTIR and 1HNMR spectroscopic methods. A DSC endothermic transition at 229oC indicated melting followed by thermal polymerization of ECCR. ECCR is thermally stable up to 320oC and follows three-step degradation kinetics. The first step followed first-order degradation kinetics, while the second and third steps followed one-half-order degradation kinetics. High values of kinetic parameters suggested the rigid nature of the crosslinked resin. Jute-, Glass- and Jute-natural fiber-ECCR composites showed moderate tensile strength, flexural strength, electric strength, and volume resistivity due to the rigid nature and poor interfacial adhesion of the composites. J-ECCR and G-ECCR composites showed high water absorption tendency and excellent hydrolytic stability against water, 10% aq. HCl and 10% aq. NaCl and even in boiling water. Mechanical and electrical properties and water absorption tendency of the composites indicated their usefulness as low load-bearing housing and insulating materials. They can also be utilized in harsh environmental conditions.

Grain Yield and Quality Losses Caused by Tan Spot in Wheat Cultivars in Australia

Tan spot (TS), known in Australia as yellow leaf spot, is caused by the fungal pathogen Pyrenophora tritici-repentis, a major foliar disease of wheat. Four experiments were conducted between 2016 and 2017 in two different climatic zones of southeastern Australia to determine the impact of TS on grain yield and quality in six wheat cultivars with different resistance ratings. In each experiment, high and low TS disease scenarios were applied to each cultivar. Disease severity was assessed as either whole-plot percentage leaf area affected (%LAA) or top three leaf (flag to flag-2) %LAA. Whole-plot %LAA was analyzed using both repeated measurements and area under the disease progress curve (AUDPC). For whole-plot %LAA, the repeated measurements identified differences in epidemic progression at key growth stages not identified through AUDPC. Both AUDPC and end-of-season flag to flag-2 %LAA were negatively correlated with grain yield and screenings. Increased rainfall impacting disease development and number of rain days above 5 mm increased TS severity across both climatic zones. Cultivar resistance ratings influenced grain yield loss, with moderately resistant, moderately susceptible, and susceptible cultivars losing up to 6, 18, and 24% grain yield, respectively. High disease significantly increased screenings by up to 1, 3, and 5% for moderately resistant, moderately susceptible, and susceptible cultivars, respectively. This study demonstrated that TS can cause significant grain yield losses in southeastern Australia, and a minimum cultivar rating of moderate resistance to moderate susceptibility was required to prevent severe TS and associated grain yield and quality losses. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Genome-Wide Association Studies on Chinese Wheat Cultivars Reveal a Novel Fusarium Crown Rot Resistance Quantitative Trait Locus on Chromosome 3BL.

Fusarium crown rot (FCR), primarily caused by Fusarium pseudograminearum, has emerged as a new threat to wheat production and quality in North China. Genetic enhancement of wheat resistance to FCR remains the most effective approach for disease control. In this study, we phenotyped 435 Chinese wheat cultivars through FCR inoculation at the seedling stage in a greenhouse. Our findings revealed that only approximately 10.8% of the wheat germplasms displayed moderate or high resistance to FCR. A genome-wide association study (GWAS) using high-density 660K SNP led to the discovery of a novel quantitative trait locus on the long arm of chromosome 3B, designated as Qfcr.hebau-3BL. A total of 12 significantly associated SNPs were closely clustered within a 1.05 Mb physical interval. SNP-based molecular markers were developed to facilitate the practical application of Qfcr.hebau-3BL. Among the five candidate FCR resistance genes within the Qfcr.hebau-3BL, we focused on TraesCS3B02G307700, which encodes a protein kinase, due to its expression pattern. Functional validation revealed two transcripts, TaSTK1.1 and TaSTK1.2, with opposing roles in plant resistance to fungal disease. These findings provide insights into the genetic basis of FCR resistance in wheat and offer valuable resources for breeding resistant varieties.

Identification of sources of resistance among potato breeding material against stem nematode

Goal. To identify new sources of resistance against stem nematode among potato breeding material and provide recommendations for the involvement of the most promising genotypes in breeding practice.&#x0D; Methods. The research was conducted in the breeding laboratory of the Polissia Research Department of the Institute for Potato Research, during 2018—2022, with promising source material of its own potato breeding, interspecific hybrids of the laboratory of genetic resources of the Institute for Potato Research and potato varieties and studied their resistance to stem nematode on an infectious background.&#x0D; Results. It was found that among the studied hybrid potato material, up to 9% of highly resistant forms, about 15—29% with relatively high and 41—62% of genotypes with moderate resistance were distinguished. Among the evaluated potato varieties, only a small number demonstrate high resistance, while the majority exhibit moderate resistance to the nematode. Sources with high, relatively high and moderate resistance to the nematode among promising potato hybrids were identified. Selected genotypes are the following: G.10.7/13, P.14.17-14, P.15.5/27, G.09.8-14, Z.14.64/3, P.13.26/13, G.08.194/122, Z.14.64-2, G.15.1-3, Z.14.49-7 and P.14.43-18 combine resistance to stem nematode with high expression of the main economically valuable traits. It was found that the breeding material that showed moderate resistance to the nematode was created with the participation of potato varieties: Santarka, Radomysl, Irbytskyi, Podoliia, Bellarossa, Satina, Tyras, Vektar and Hurman. As a result of targeted breeding work, three new potato varieties have been created: Fanatka, Rostavytsia and Dzhavelina, characterised by high productivity, drought tolerance, and resistance to stem nematode and quarantine microorganisms.&#x0D; Conclusions. We recommend using the selected stem nematode-resistant hybrids in breeding work to develop resistant potato varieties. To limit the spread and development of the nematode, we recommend cultivating the suggested resistant potato varieties.

First report of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) resistance to spirotetramat in Florida

One of the most destructive invasive pests worldwide is the whitefly, Bemisia tabaci MEAM1. The Florida vegetable crop market, worth millions of dollars annually, suffers major losses because of whitefly injury. Spirotetramat is frequently used by Florida vegetable crop growers to control whitefly nymphs. A previous study based on maximum dose bioassays indicated that MEAM1 populations in Florida may be developing resistance to spirotetramat. Thus, the long-term efficacy of this active ingredient depends on the development of baseline susceptibility data and the continued monitoring of MEAM1 populations' susceptibility. In the present study, 16 populations of whiteflies collected in south Florida were tested for resistance to spirotetramat through serial dilution bioassays designed to test whitefly nymphs. The field populations’ responses were compared with a susceptible MEAM1 laboratory colony. Median lethal concentrations (LC50) and resistance ratios (RRs) were quantified to determine MEAM1 resistance levels. Among the populations tested, 12.5% remained relatively susceptible (3–4 RR) to spirotetramat. Low to moderate resistance was found in 56% of the populations (16–58 RR). Over 30% of the populations tested were highly or extremely resistant (126–795 RR). Overall, the variable susceptibility of spirotetramat in some field populations indicates that resistance to this insecticide has developed in certain regions of south Florida. This is the first report of spirotetramat resistance in the United States. These results will directly refine management recommendations for spirotetramat use in areas where MEAM1 populations exhibit resistance.

Typing and Integron Distribution among Multi-Drug Resistance Escherichia coli

The study aimed, through the use of taxonomic associations, to find the genetic relationship between strains of Escherichia coli bacteria in 152 samples of infection symptoms. The results of the susceptibility test for 42 isolates showed that 8 isolates were sensitive to most antibiotics, while 12 isolates had moderate resistance, ranging from 5-8 antagonists, while 22 isolates were resistant to 9-12 antibiotics. Through the use of phylo-group profiling system it was found that the vast majority of Escherichia coli isolates under study have high virulence factors and possess large genomes by belonging to group B2. The results of genotyping using the PCR-Integron system showed that the unty Pable isolates were only... and that the highest percentage was in the first type, which reached... which indicates that there is a relationship between resistance to multiple antibiotics and the presence of introns.

Flip-Chip Interconnects Based on Single Metal-Coated Polymer Spheres

In microelectronics packaging, minimizing thermomechanical stresses is crucial to achieve high reliability. This paper presents a novel approach for flip-chip interconnects, utilizing individual metal-coated polymer spheres at a low bonding temperature. The method involves selectively depositing individual conductive particles onto a polydimethylsiloxane (PDMS) carrier and then transferring the particles to electrical pads on substrate using Ag sintering followed by die placement and introducing underfill material. The deposition process achieved a high yield of 98.8% on the PDMS carrier, while the transferring process resulted in well-defined ink dots with a yield of 96.2%. The sintered Ag formed good bonds between the particles and electrical pads, leading to moderate interconnect resistance (as low as 0.57 Ω). This work has demonstrated the feasibility of interconnects based on a single metal-coated polymer sphere with low thermomechanical stress induced, thanks to the low bonding temperature (140 °C) and pressure (0.1 MPa) as well as the mechanical compliance of polymer particles.

Repassivation-oriented pitting corrosion analysis in a cause-effect relationship with microstructure, precipitation, and mechanical behavior of low-carbon medium-chromium ferritic stainless steel

Ferritic stainless steels (FSS), which are potentially ferromagnetic, play a vital role in electromagnetic applications, including solenoid valves, owing to their ferromagnetic properties. This study delves into the microstructure's impact on the localized pitting corrosion behaviour of cold-drawn (CD) low-carbon medium-chromium ferritic/ferromagnetic EN1.4106. Employing potentiostatic-based corrosion analysis, mechanical assessments, and microstructural evaluations on 44 designated specimens subjected to varied annealing conditions, we unveil a nuanced correlation between corrosion resistance and microstructure. Lower reduction rate of 15% versus 45%, extended-enough annealing conditions, and meticulous microstructural control with average grain size of around 45–46 μm, particularly in minimizing dislocation density alongside the local misorientaion of 15° up to at most 35°, significantly enhance corrosion resistance. Overall, this FSS grade demonstrates commendable non-hardenable characteristics with moderate resistance to pitting corrosion in the two of the most corrosive (acidic and chlorinated) environments. The grade notably passivates in sulfuric acid electrolyte solution (SAES) but undergoes active anodic dissolution in sodium chloride electrolyte solution (SCES), ultimately forming a sort of passive-like oxide layer.

The HOG-pathway related AaOS1 leads to dicarboximide-resistance in field strains of Alternaria alternata and contributes, together with the Aafhk1, to mycotoxin production and virulence.

Garlic leaf spot (GLS) caused by Alternaria alternata is one of the main diseases in the garlic production areas, and its management heavily relies on dicarboximide fungicides. However, the efficacy of dicarboximides against the GLS disease has decreased year on year. In the present study, 10 of 148 A. alternata strains separated from Jiangsu Province were moderately resistant (MR) to a dicarboximide fungicide procymidone (ProMR). Positive cross-resistance was observed between Pro and iprodione (Ipro) or fludioxonil (Fld), but not between Pro and fluazinam or azoxystrobin. Mutations at AaOS1, but not Aafhk1, were confirmed to confer the Pro resistance by constructing replacement mutants, whereas mutations at both AaOS1 and Aafhk1 decreased the gene expression level of AapksI, as well as the ability to produce mycotoxin AOH (polyketide-derived alternariol) and virulence. Additionally, more genes (AaOS1 and Aafhk1) harboring the mutations experienced a larger biological fitness penalty. To our knowledge, this is the first report on Pro resistance selected in garlic fields, and mutations at AaOS1 of A. alternata causing a decreased ability to produce the mycotoxin AOH. © 2024 Society of Chemical Industry.