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Background Bi-parental mapping populations have been commonly utilized to identify and characterize quantitative trait loci (QTL) controlling resistance to soybean cyst nematode (SCN, Heterodera glycines Ichinohe). Although this approach successfully mapped a large number of SCN resistance QTL, it captures only limited allelic diversity that exists in parental lines, and it also has limitations for genomic resolution. In this study, a genome-wide association study (GWAS) was performed using a diverse set of 553 soybean plant introductions (PIs) belonging to maturity groups from III to V to detect QTL/genes associated with SCN resistance to HG Type 0. Results Over 45,000 single nucleotide polymorphism (SNP) markers generated by the SoySNP50K iSelect BeadChip ( http// www.soybase.org ) were utilized for analysis. GWAS identified 14 loci distributed over different chromosomes comprising 60 SNPs significantly associated with SCN resistance. Results also confirmed six QTL that were previously mapped using bi-parental populations, including the rhg1 and Rhg4 loci. GWAS identified eight novel QTL, including QTL on chromosome 10, which we have previously mapped by using a bi-parental population. In addition to the known loci for four simple traits, such as seed coat color, flower color, pubescence color, and stem growth habit, two traits, like lodging and pod shattering, having moderately complex inheritance have been confirmed with great precision by GWAS. Conclusions The study showed that GWAS can be employed as an effective strategy for identifying complex traits in soybean and for narrowing GWAS-defined genomic regions, which facilitates positional cloning of the causal gene(s).

Plant-parasitic nematodes are one of the most economically impactful pests in agriculture resulting in billions of dollars in realized annual losses worldwide. Soybean cyst nematode (SCN) is the number one biotic constraint on soybean production making it a priority for the discovery, validation and functional characterization of native plant resistance genes and genetic modes of action that can be deployed to improve soybean yield across the globe. Here, we present the discovery and functional characterization of a soybean resistance gene, GmSNAP02 . We use unique bi-parental populations to fine-map the precise genomic location, and a combination of whole genome resequencing and gene fragment PCR amplifications to identify and confirm causal haplotypes. Lastly, we validate our candidate gene using CRISPR-Cas9 genome editing and observe a gain of resistance in edited plants. This demonstrates that the GmSNAP02 gene confers a unique mode of resistance to SCN through loss-of-function mutations that implicate GmSNAP02 as a nematode virulence target. We highlight the immediate impact of utilizing GmSNAP02 as a genome-editing-amenable target to diversify nematode resistance in commercially available cultivars. Here, the authors show that the soybean GmSNAP02 gene confers a unique mode of resistance to the soybean cyst nematode Heterodera glycines through loss-of-function mutations that implicate GmSNAP02 as a nematode virulence target.

Soybean cyst nematode (SCN) is a destructive pathogen of soybeans responsible for annual yield loss exceeding $1.5 billion in the United States. Here, we conducted a series of genome-wide association studies (GWASs) to understand the genetic landscape of SCN resistance in the University of Missouri soybean breeding programs (Missouri panel), as well as germplasm and cultivars within the United States Department of Agriculture (USDA) Uniform Soybean Tests—Northern Region (NUST). For the Missouri panel, we evaluated the resistance of breeding lines to SCN populations HG 2.5.7 (Race 1), HG 1.2.5.7 (Race 2), HG 0 (Race 3), HG 2.5.7 (Race 5), and HG 1.3.6.7 (Race 14) and identified seven quantitative trait nucleotides (QTNs) associated with SCN resistance on chromosomes 2, 8, 11, 14, 17, and 18. Additionally, we evaluated breeding lines in the NUST panel for resistance to SCN populations HG 2.5.7 (Race 1) and HG 0 (Race 3), and we found three SCN resistance-associated QTNs on chromosomes 7 and 18. Through these analyses, we were able to decipher the impact of seven major genetic loci, including three novel loci, on resistance to several SCN populations and identified candidate genes within each locus. Further, we identified favorable allelic combinations for resistance to individual SCN HG types and provided a list of available germplasm for integration of these unique alleles into soybean breeding programs. Overall, this study offers valuable insight into the landscape of SCN resistance loci in U.S. public soybean breeding programs and provides a framework to develop new and improved soybean cultivars with diverse plant genetic modes of SCN resistance.

Although pyraclostrobin {carbamic acid, [2,[[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy]methyl]phenyl]methoxy-,methyl ester} has been used to protect soybean [Glycine max (L.) Merr.] from foliar diseases, its interaction with drainage water management (DWM) systems was unknown. Field research during two wet years (95 to 97 mm greater than the past decade) evaluated the effects of pyraclostrobin application timing (R3, R5, R3+R5, and R3+R5+lambda-cyhalothrin) and DWM system (nondrained and drainage only [DO] or drainage plus subirrigation [DSI] at 6.1 and 12.2 m drain tile spacings) on soybean yield, grain quality, and severity of Septoria brown spot (SBS) (Septoria glycines) and frogeye leaf spot (FLS) (Cercospora sojina). Grain yields increased 18 to 22% with DO or DSI at 6.1 and 12.2 m spacings compared to a nonfungicide treated, nondrained control. In the absence of drainage, pyraclostrobin with or without lambda-cyhalothrin increased yields 20 to 27% compared to the nondrained, nonfungicide treated control. The combination of DWM and pyraclostrobin increased grain yields up to 36%. Pyraclostrobin plus lambda-cyhalothrin at R3+R5 increased yield 8 to 12% except with DO at 12.2 m compared to similar nonfungicide-treated DWM systems. A DWM and pyraclostrobin interaction was detected for grain oil and protein concentration, but differences were minimal. Pyraclostrobin with or without lambda-cyhalothrin reduced severity of SBS and FLS 2 to 8% depending on the year, but DWM did not affect severity of these diseases. The greatest synergistic yield increase on a claypan soil occurred when foliar disease management and DWM systems were used together in years with higher than normal rainfall.

We present the technological verification of a size-optimized 160-channel, 50-GHz silicon nitride-based AWG-spectrometer. The spectrometer was designed for TM-polarized light with a central wavelength of 850 nm applying our proprietary “AWG-Parameters” tool. For the simulations of AWG layout, the WDM PHASAR photonics tool from Optiwave was used. The simulated results show satisfying optical properties of the designed AWG-spectrometer. However, the high-channel count causes a large AWG size with standard design approaches. To solve this problem we designed a special taper enabling the reduction of AWG structure by about 15% while keeping the same optical properties. The AWG design was fabricated and the measured spectra not only confirm the proposed size-reduction but also the improvement of optical properties of the size-optimized AWG.

Objective:To evaluate the incidence of coronary vasospasm as a possible pathophysiological mechanism causing chest pain symptoms in patients with clinically suspected myocarditis.Design and setting:Prospective study in a teaching hospital.Patients:85 patients who presented at hospital with atypical chest pain and demonstrated clinical signs suggestive of myocarditis.Main outcome measures:Incidence of coronary vasospasm demonstrated by intracoronary acetylcholine (ACh) testing.Methods:The combined procedure of intracoronary ACh testing and endomyocardial biopsy (EMB) was performed after ruling out significant coronary artery disease (CAD). EMBs were analysed for myocardial inflammation by immunohistological methods and for virus genome persistence.Results:Pathological biopsy results, including myocardial inflammation or detection of viral genomes, or both, were found in 55 (64.7%) patients while 30 (35.3%) patients showed neither cardiac inflammation nor viral genomes and were defined as the control group. Coronary vasospasm was demonstrated in 39/55 (70.9%) patients with pathological results compared with only 12/30 (40.0%) with normal biopsy results (p = 0.01). Patients with isolated PVB19 infection (n = 22) demonstrated a significantly higher incidence of coronary vasospasm than both those with isolated HHV6 infection (86.4% vs 46.7%; p = 0.025) and those with normal biopsy results (86.4% vs 40.0%; p<0.001). Univariate and multivariate logistic regression analysis showed that only PVB19 infection was independently correlated with coronary vasospasm (OR = 4.9, 95% CI 1.56 to 15.28, p = 0.006).Conclusions:Coronary vasospasm is one of the main reasons for atypical chest pain in patients with clinical signs of myocarditis and biopsy-proven PVB19 myocarditis in the absence of significant CAD.

Key messageAn epistatic interaction between SCN resistance loci rhg1-a and rhg2 in PI 90763 imparts resistance against virulent SCN populations which can be employed to diversify SCN resistance in soybean cultivars.With more than 95% of the $46.1B soybean market dominated by a single type of genetic resistance, breeding for soybean cyst nematode (SCN)-resistant soybean that can effectively combat the widespread increase in virulent SCN populations presents a significant challenge. Rhg genes (for Resistance to Heterodera glycines) play a key role in resistance to SCN; however, their deployment beyond the use of the rhg1-b allele has been limited. In this study, quantitative trait loci (QTL) were mapped using PI 90763 through two biparental F3:4 recombinant inbred line (RIL) populations segregating for rhg1-a and rhg1-b alleles against a SCN HG type 1.2.5.7 (Race 2) population. QTL located on chromosome 18 (rhg1-a) and chromosome 11 (rhg2) were determined to confer SCN resistance in PI 90763. The rhg2 gene was fine-mapped to a 169-Kbp region pinpointing GmSNAP11 as the strongest candidate gene. We demonstrated a unique epistatic interaction between rhg1-a and rhg2 loci that not only confers resistance to multiple virulent SCN populations. Further, we showed that pyramiding rhg2 with the conventional mode of resistance, rhg1-b, is ineffective against these virulent SCN populations. This highlights the importance of pyramiding rhg1-a and rhg2 to maximize the impact of gene pyramiding strategies toward management of SCN populations virulent on rhg1-b sources of resistance. Our results lay the foundation for the next generation of soybean resistance breeding to combat the number one pathogen of soybean.

Corn (Zea mays L.) response to boron (B) on fine textured soils has had limited research, and no research has evaluated interactions between B and crop protection chemicals such as pyraclostrobin. This research evaluated effects of foliar-applied B at 0.56 kg ha−1 and pyraclostrobin {carbamic acid, [2,[[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy]methyl]phenyl]methoxy-, methyl ester} at 0.11 kg ha−1 a.i. on yield, tissue B concentration, severity of disease, and grain quality. Field research was conducted at four locations in Northeast Missouri from 2008 to 2010. Boron was applied at V5–V6, V5–V6 followed by (fb) pyraclostrobin at VT, and with or without pyraclostrobin at VT. Pyraclostrobin was applied alone at VT, and a nontreated control was also included. Over the 12 site-years, pyraclostrobin alone at VT increased yield 5% and B at V5–V6 fb pyraclostrobin at VT increased yield 6% compared to the nontreated control. A split-application of B at V5–V6 fb pyraclostrobin at VT increased yield 0.52 Mg ha−1 compared to B plus pyraclostrobin at VT. Pyraclostrobin increased grain moisture 3 to 7 g kg−1, decreased starch 1 to 2 g kg−1, and decreased extractable starch 3 to 4 g kg−1 concentration compared to the nontreated control. However, no difference in the number of barren stalks, grain with diplodia (Stenocarpella maydis) symptoms, oil, or protein concentrations was detected among treatments. Disease severity was reduced most consistently with B at V5–V6 fb pyraclostrobin or pyraclostrobin alone. Boron at 0.56 kg ha−1should be applied before VT to avoid antagonism with pyraclostrobin on fine textured soils.

Integrated water management systems using drainage plus subirrigation (DSI) have reduced nitrate-loading of drainage water flow and may increase soybean [Glycine max (L.) Merr.] yield. Shallow drain tile depths and narrow spacings are recommended for claypan soils. Field research (2003–2006) evaluated the effects of drainage (DO) and DSI on planting date and the effects of DO and DSI at 6.1 and 12.2 m spacings on soybean yield compared to nondrained (ND) and nondrained delayed planting (NDDP) controls on claypan soils. Soybean were planted up to 17 d earlier with DO or DSI systems. Plant populations were reduced 29 to 52% in the nondrained control due to poor drainage in 3 of the 4 yr. Grain yield, water applied through the DSI system, and water level depth were similar at a 6.1 or 12.2 m drain tile spacing. Average yield increase with DSI at 6.1 and 12.2 m spacings was 12 to 29% (410–910 kg ha−1) while DO at the same spacings increased yield 9 to 22% (300–710 kg ha−1) compared to ND or NDDP controls. In a dry year (2005), drainage plus subirrigation increased yield up to 1200 kg ha−1 compared to DO. Plant population variability at harvest was lower with the DO or DSI systems compared to ND or NDDP controls. Yield variability over the 4 yr was lower with DSI compared with DO or ND controls, which was affected by the spring–summer precipitation regimes and is important to farmers for a more predictable soybean marketing strategy.

More than half of breast cancers express low levels of HER2. In a phase 3 trial, the antibody–drug conjugate trastuzumab deruxtecan resulted in longer survival than the physician’s choice of chemotherapy among patients with HER2-low breast cancer.