Search

Stripe rust or yellow rust (YR), caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat (Triticum aestivum L.). Widespread deployment of resistant cultivars is the best means of achieving durable disease control. The red grain, spring wheat cultivar Napo 63 produced by CIMMYT in the 1960s shows a high level of adult-plant resistance to stripe rust in the field. To elucidate the genetic basis of resistance in this cultivar we evaluated 224 F2:3 lines and 175 F2:6 recombinant inbred lines (RILs) derived from a cross between Napo 63 and the Pst-susceptible line Avocet S. The maximum disease severity (MDS) data of F2:3 lines and the relative area under the disease progress curve (rAUDPC) data of RILs were collected during the 2014-2015 and 2015-2016 wheat growing seasons, respectively. Combined bulked segregant analysis and 90K single nucleotide polymorphism (SNP) arrays placed 275 of 511 polymorphic SNPs on chromosome 2B. Sixty four KASP markers selected from the 275 SNPs and 76 SSR markers on 2B were used to identify a chromosome region associated with rust response. A major effect QTL, named Qyrnap.nwafu-2BS, was identified by inclusive composite interval mapping and was preliminarily mapped to a 5.46 cM interval flanked by KASP markers 90K-AN34 and 90K-AN36 in chromosome 2BS. Fourteen KASP markers more closely linked to the locus were developed following a 660K SNP array analysis. The QTL region was finally narrowed to a 0.9 cM interval flanked by KASP markers 660K-AN21 and 660K-AN57 in bin region 2BS-1-0.53. The resistance of Napo 63 was stable across all environments, and as a QTL, explained an average 66.1% of the phenotypic variance in MDS of F2:3 lines and 55.7% of the phenotypic variance in rAUDPC of F5:6 RILs. The short genetic interval and flanking KASP markers developed in the study will facilitate marker-assisted selection, gene pyramiding, and eventual positional cloning of Qyrnap.nwafu-2BS. [ABSTRACT FROM AUTHOR]

We theoretically and numerically investigate all-optical Mach–Zehnder interferometer switching based on the phase-shift multiplication effect of an all-optical analog on the electromagnetically induced transparency effect. The free-carrier plasma dispersion effect modulation method is applied to improve the tuning rate with a response time of picoseconds. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Compared with no phase-shift multiplication effect, the average pump power of all-optical switching required to yield the π-phase shift difference decreases by 55.1%, and the size of the modulation region is reduced by 50.1% when the average pump power reaches 60.8 mW. This work provides a new direction for low-power consumption and miniaturization of microstructure integration light-controlled switching devices in optical communication and quantum information processing. [ABSTRACT FROM AUTHOR]

The Chehugou Mo-Cu deposit, located 56 km west of Chifeng, NE China, is hosted by Triassic granite porphyry. Molybdenite-chalcopyrite mineralization of the deposit mainly occurs as veinlets in stockwork ore and dissemination in breccia ore, and two ore-bearing quartz veins crop out to the south of the granite porphyry stock. Based on crosscutting relationships and mineral paragenesis, three hydrothermal stages are identified: (i) quartz-pyrite-molybdenite ± chalcopyrite stage; (ii) pyrite-quartz ± sphalerite stage; and (iii) quartz-calcite ± pyrite ± fluorite stage. Three types of fluid inclusions in the stockwork and breccia ore are recognized: LV, two-phase aqueous inclusions (liquid-rich); LVS, three-phase liquid, vapor, and salt daughter crystal inclusions; and VL, two-phase aqueous inclusions (gas-rich). LV and LVS fluid inclusions are recognized in vein ore. Microthermometric investigation of the three types of fluid inclusions in hydrothermal quartz from the stockwork, breccia, and vein ores shows salinities from 1.57 to 66.75 wt% NaCl equivalents, with homogenization temperatures varying from 114°C to 550°C. The temperature changed from 282-550°C, 220-318°C to 114-243°C from the first stage to the third stage. The homogenization temperatures and salinity of the LV, LVS and VL inclusions are 114-442°C and 1.57-14.25 wt% NaCl equivalent, 301-550°C and 31.01-66.75 wt% NaCl equivalent, 286-420°C and 4.65-11.1 wt% NaCl equivalent, respectively. The VL inclusions coexist with the LV and LVS, which homogenize at the similar temperature. The above evidence shows that fluid-boiling occurred in the ore-forming stage. δ [ABSTRACT FROM AUTHOR]

The Baiyinnuoer deposit (32.74 Mt ore with grades of 5.44% Zn, 2.02% Pb and 31.36 g t−1 Ag), the largest Zn-Pb-Ag deposit in northern China, is hosted by crystalline limestone and slate of the Early Permian Huanggangliang Formation. Detailed cross-section mapping indicates stratigraphic and fold structural controls on the mineralization. The Zn-Pb-Ag mineralization is hosted predominantly by skarn, which occurs as bedding-parallel lens that pinch out at the margins of the main economic zone. Three skarn stages are identified at the deposit: (i) garnet-clinopyroxene; (ii) sulfides; and (iii) carbonate-epidote. Lead isotopic compositions were determined for galena and sphalerite of the ores, whole rock samples of the Yanshanian granite and granodiorite, Permian marble and tuff, and Jurassic volcanic and subvolcanic rocks in and around the Baiyinnuoer area in order to discuss the sources of ore-forming materials and the relationship between the ore formation and these whole rocks. Galena and sphalerite of the Baiyinnuoer ore have uniform isotopic ratios (206Pb/204Pb, 18.267–18.369; 207Pb/204Pb, 15.506–15.624; 208Pb/204Pb, 38.078–38.394) consistent with the granite and granodiorite (206Pb/204Pb, 18.252–18.346; 207Pb/204Pb, 15.504–15.560; 208Pb/204Pb, 38.141–38.320), whereas the ratios for Jurassic volcanic and subvolcanic rocks are variable and radiogenic (206Pb/204Pb, 18.468–18.614; 207Pb/204Pb, 15.521–15.557; 208Pb/204Pb, 38.304–38.375). These results indicate that the mineralization was not related to the Jurassic volcanism, but to the Yanshanian magmatism. The Permian strata may have a slight contribution to the mineralization. All features show that the Baiyinnuoer deposit is related to the Yanshanian granitic magmatism, and can be classified as a zinc-lead-silver skarn deposit. [ABSTRACT FROM AUTHOR]

The Kuoerzhenkuola gold deposit is located in the Sawur gold belt in Xinjiang, China. An integrated geological, geochemical and geophysical investigation was carried out in the Kuoerzhenkuola gold deposit, to determine the extension of the principal mineralized system, in the search for new resources. Re-examination of the rocks and structures in the Kuoerzhenkuola area showed that the study area features an elliptical caldera where the gold deposit lies. A re-investigation of the mine geology found that the mineralization at the Kuoerzhenkuola gold deposit is not controlled by the EW-striking regional fault as previously assumed, but by a caldera fracture system locally superimposed by regional faults; the host rocks are andesites and dacites of the Carboniferous Heishantou Group rather than the crypto-explosive breccia of the Devonian Sawurshan Group. Gas components of fluid inclusions from quartz, trace element chemistry of pyrite and fluid inclusions in pyrite, Pb isotopes of pyrite, and whole-rock geochemistry and Pb isotopes of the country rocks are used to study the source of fluids at Kuoerzhenkuola gold deposit. The ore-forming fluids are characterized by low–moderate temperatures and low salinities estimated from fluid inclusion microthermometry. Quadrupole mass spectrometry indicated a CO2-bearing fluid. Inductively coupled plasma–mass spectrometry of the fluid inclusions indicated high Cu (average 70 ppm) for the Au mineralization, whereas the host rocks have low Cu (average 33 ppm), indicating that Cu of the ore-forming fluids originated from magmatic fluid rather than the volcanic rocks. Pb isotopes of ores and host volcanic rocks indicate a similar, mixed source and some Pb could be sourced from the volcanism. This implied that magmatic fluids could play an important role in the Au mineralization process. These new geological findings and the fluids derived mainly from the magmatic fluids suggest that the ore-forming fluids originate at depth, and are transported and precipitated within the caldera fracture system. Thus, we proposed a conceptual target area at depth. A detailed Stratagem EH4 measurement was carried out to test the validity of the conceptual target. Stratagem EH4 soundings over six parallel traverses perpendicular to the mineralized trend showed that the caldera fracture system could extend for approximately 900 m in the dip direction at the center of the caldera, an indication of the presence of potential deep mineralization under the surveyed area. Detailed modeling of the Stratagem EH4 sounding images provided well-defined targets for test drilling. Subsequent test drilling on one of these targets, which extends down 850 m at an angle of 87°, returned encouraging results because four core-intercepts of gold ore bodies at down-hole depths of 40.5–42.0 m, 70.5–73.5 m, 357.0–358.5 m, and 384.5–385.5 m and a long interval gold mineralized body (0–720 m) were encountered. [ABSTRACT FROM AUTHOR]

An integrated geological and geophysical investigation was carried out in the near-mine areas of the Chaihulanzi gold-field, Inner Mongolia, northern China, to determine the south-eastern strike extension of the principal mineralized shear system, in the search for new resources. In this case study, surface geophysical surveys played an important role in defining the mineralized structures beneath cover. A re-investigation of the mine geology by observing the underground exposures of mineralization and its hosting structures, coupled with re-evaluation and re-examination of previous exploration data, revealed that the mineralization style at the Chaihulanzi gold-field is not the skarn-type as previously assumed, but is structurally controlled by an oblique-sinistral shear structure. Moreover, a south-eastward shallow-plunging mineralized corridor within the principal mineralized shear system was also identified, implying that the ore-forming fluid-flow might move through the mineralizing system, from the south-east at depth to the north-west. These new geological findings imply that the mineralized shear system should extend much farther south-eastwards along strike beneath cover, and thus a conceptual target area was proposed. A detailed geophysical survey program, involving the application of VLF-EM, Stratagem EH4, CSAMT and gradient IP measurements, was carried out to test the validity of the conceptual target. Orientation surveys on the geologically known Line-18 traverse revealed that VLF-EM and Stratagem EH4 were the most effective methods of detecting the unseen mineralized system, whereas CSAMT could only provide low-resolution data, and IP proved to be unsuitable in this environment due to the ubiquitous presence of graphite-bearing schists in and around the mineralized system. A follow-up systematic VLF-EM survey highlighted the principal mineralized shear system as a linear conductive belt, tracing the principal mineralized system for a further 750 m of strike length beneath cover from the previous exploration limit (Line 18). Stratagem EH4 soundings over six parallel traverses perpendicular to the mineralized trend revealed that the principal mineralized shear structure extends for more than 500 m in the dip direction, a strong indication of the presence of potential deep mineralization under the surveyed area. Detailed modelling of the Stratagem EH4 sounding images provided well-defined targets for test drilling. Subsequent test drilling on some of these targets returned encouraging results as several core-intercepts of economic gold mineralization were encountered. This led to a more extensive drilling and underground prospecting program, focusing on deep mineralization south-eastwards along the mineralized trend. [ABSTRACT FROM AUTHOR]

The main objective of the current study was to examine the anticancer effects of naturally occurring Hirsutenone in human thyroid cancer cells along with investigating its effects on cell migration and invasion, apoptosis and Wnt/Beta-catenin signalling pathway. MTT assay and clonogenic assay were used to study effects on cell viability and cancer colony formation. Fluorescence microscopy along with flow cytometry was used to study apoptotic effects induced by Hirsutenone. Effects on Wnt/Beta-catenin signalling pathway were examined by western blot assay. Results indicated that Hirsutenone led to potent cell proliferation inhibition along with reducing cancer colony formation in a dose-dependent manner. Hirsutenone induced apoptotic effects as indicated by acridine orange/ethidium bromide staining assay as well as annexin-V FITC assay. The percentage of both early and late apoptotic cells increased significantly with increasing doses of Hirsutenone. Hirsutenone also caused activation of CASPASE-3, CASPASE-9, and BAX while as it led to downregulation of BCL-2. Hirsutenone also caused the inhibition of cell migration and cell invasion along with causing suppression of Wnt/beta-catenin signalling pathway. In conclusion, Hirsutenone exhibits strong anticancer properties in human thyroid cancer cells mediated via apoptosis, cell migration and invasion inhibition and suppression of Wnt/beta-catenin signalling pathway. [ABSTRACT FROM AUTHOR]

We theoretically and numerically investigate a low-power, ultrafast, and dynamic all-optical tunable plasmon induced transparency (PIT) in two stub resonators side-coupled with a metal-dielectric-metal (MDM) plasmonic waveguide system. The optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons (SPPs) and the plasmonic waveguide based on graphene-Ag composite material structures with large effective Kerr nonlinear coefficient. An ultrafast response time of the order of 1 ps is reached because of ultrafast carrier relaxation dynamics of graphene. With dynamically tuning the propagation phase of the plasmonic waveguide, π-phase shift of the transmission spectrum in the PIT system is achieved under excitation of a pump light with an intensity as low as 5.8 MW cm−2. The group delay is controlled between 0.14 and 0.67 ps. Moreover, the tunable bandwidth of about 42 nm is obtained. For the indirect coupling between two stub cavities or the phase coupling scheme, the phase shift multiplication effect of the PIT effect is found. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. This work not only paves the way towards the realization of on-chip integrated nanophotonic devices but also opens the possibility of the construction of ultrahigh-speed information processing chips based on plasmonic circuits. [ABSTRACT FROM AUTHOR]

The development and deployment of diverse resistance sources in new wheat cultivars underpin the durable control of stripe rust. In the present study, two loci for adult plant resistance (APR), QYrSM155.1 and QYrSM155.2, were identified in the Chinese wheat breeding line Shaanmai 155. QYrSM155.1 was mapped to a 3.0-cM interval between the single-nucleotide polymorphism (SNP) markers AX-109583610 and AX-110907562 on chromosome arm 2BL. QYrSM155.2 was mapped to a 2.1-cM interval flanked by the SNP markers AX-110378556 and AX-86173526 on chromosome arm 7AS. A genome-wide association study was used to identify markers associated with APR in a panel of 411 spring wheat lines. Thirteen and 11 SNPs were significantly associated with QYrSM155.1 and QYrSM155.2, respectively, corresponding to physical intervals of 653.75-655.52 Mb on 2BL and 81.63-83.93 Mb on 7AS. To characterize the haplotype variation and the distribution of these QTL, haplotype analysis was performed based on these SNPs in an independent panel of 1101 worldwide wheat accessions. Three major haplotypes (2B_h1, 2B_h2, and 2B_h3) for QYrSM155.1 and four major haplotypes (7A_h1, 7A_h2, 7A_h3, and 7A_h4) for QYrSM155.2 were identified. Accessions individually harboring QYrSM155.1_h1 and QYrSM155.2_h1 haplotypes and their combination displayed resistance. Additional assays of 1306 current Chinese cultivars and breeding lines using markers flanking QYrSM155.1 and QYrSM155.2 indicated that the resistance haplotypes of the two QTL were present in respectively 1.45% and 14.16% of lines. Increasing resistance haplotype frequencies at these two loci using marker-assisted selection should benefit wheat production in China. [ABSTRACT FROM AUTHOR]

Breeding for resistance to stripe rust (caused by Puccinia striiformis f. tritici) is essential for reducing losses in yield and quality in wheat. To identify genes for use in breeding, a biparental population of 186 recombinant inbred lines (RILs) from a cross of the Chinese landrace Mingxian 169 and CLMMYT-derived line P9936 was evaluated in field nurseries either artificially or naturally inoculated in two crop seasons. Each of the RILs and parents was genotyped with the wheat 55K single-nucleotide polymorphism (SNP) ‘Breeders’ array and a genetic linkage map with 8,225 polymorphic SNP markers spanning 3,593.37 centimorgans was constructed. Two major quantitative trait loci (QTL) and two minor QTL were identified. The major QTL QYi:nwafu-3BS.2 and QYr.nwafu-7BL on chromosomes arms 3BS and 7BL were detected in all field locations and explained an average 20.4 and 38.9% of phenotypic variation stripe rust severity, respectively. QYr.nwafu-3BS.2 likely corresponds to the locus Yr30/Sr2 and QYr.nwafu-7BL may be a resistance allele identified previously in CIMMYT germplasm. The other minor QTL had limited individual effects but increased resistance when in combinations with other QTL. Market's linked to QYr.nwafu-7BL were converted to kompetitive allele-specific polymerase chain reaction markers and validated in a panel of wheat accessions. Wheat accessions carrying the same haplotype as P9936 at the identified SNP loci had lower average stripe rust severity than the average severity of all other haplotypes. [ABSTRACT FROM AUTHOR]

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most devastating diseases of wheat worldwide. Growing resistant cultivars is considered the best approach to manage this disease. In order to identify the resistance gene(s) in wheat line 03031-1-5 H62, which displayed high resistance to stripe rust at adult plant stage, a cross was made between 03031- 1-5 H62 and susceptible cultivar Avocet S. The mapping population was tested with Chinese P. striiformis f. sp. tritici race CYR32 through artificial inoculation in a field in Yangling, Shaanxi Province and under natural infection in Tianshui, Gansu Province. The segregation ratios indicated that the resistance was conferred by a single dominant gene, temporarily designated as YrH62. A combination of bulked segregant analysis (BSA) with wheat 90K single nucleotide polymorphism (SNP) array was used to identify molecular markers linked to YrH62. A total of 376 polymorphic SNP loci identified from the BSA analysis were located on chromosome IB, from which 35 kompetitive allele-specific PCR (KASP) markers selected together with 84 simple sequence repeat (SSR) markers on IB were used to screen polymorphism and a chromosome region associated with rust resistance was identified. To saturate the chromosomal region covering the YrH62 locus, a 660K SNP array was used to identify more SNP markers. To develop tightly linked markers for marker-assisted selection of YrH62 in wheat breeding, 18 SNPs were converted into KASP markers. A final linkage map consisting of 15 KASP and 3 SSR markers was constructed with KASP markers AX-109352427 and AX-109862469 flanking the YrH62 locus in a 1.0 cM interval. YrH62 explained 63.8 and 69.3% of the phenotypic variation for disease severity and infection type, respectively. YrH62 was located near the centromeric region of chromosome IBS based on the positions of the SSR markers in IB deletion bins. Based on the origin, responses to P. striiformis f. sp. tritici races, and marker distances, YrH62 is likely different from the other reported stripe rust resistance genes/quantitative trait loci on IB. The gene and tightly linked KASP markers will be useful for breeding wheat cultivars with resistance to stripe rust. [ABSTRACT FROM AUTHOR]

Stripe rust (Puccinia striiformis f. sp. tritici) is among the most important diseases of wheat (Triticum aestivum L.) globally. Utilization of adult plant resistance (APR) constitutes a key tool for maintaining protection against this disease. The C1MMYT wheat cultivar P i0057 displayed a high level of APR to stripe rust in gennplasm evaluation in field environments. To clarify the genetic basis and identify quantitative trait loci (QTLs) involved in stripe rust resistance in P10057, three wheat populations were used: 150 F5:6 recombinant inbred lines (RILs) derived from the cross Mingxian 169 x P 10057, and 161 and 140 F2:3 lines from Avocet S x PI0057 and Zhengmai 9023 x PI0057, respectively. These three populations were evaluated for infection type (IT) and disease severity (DS) in Shaanxi, Gansu, and Sichuan during the 2014-15 and 2015-16 cropping seasons. Genotyping was performed with Kompetitive Allelic Specific PCR (KASP) and simple sequence repeat (SSR) markers linked to the resistance loci. Using QTL analysis, two genomic regions associated with resistance were found on chromosome arms 2BS and 3BS, respectively. These two stable QTLs, designated Qyrlov. nwafu-2BS and Qyrlov.nwafu-3BS, were detected across all environments and explained average 22.6 to 31.6% and 21.3 to 32.3% of stripe rust severity phenotypic variation, respectively. Qyrlov.nwafu-2BS may be the resistance allele derived from CIMMYT gennplasm and Qyrlov. nwafu-3BS likely corresponds to the locus Sr2/Lr27/Yr30/Pbc. The KASP markers IWA5377, IWA2674, and IWA5830 linked to QYrlov. nwafu-2BS and 1WB57990 and IWB6491 linked to Qyrlov.nwafu-3BS were reliable for marker-assisted selection (MAS) in the Zhengmai 9023 x P10057 population. These QTLs with KASP markers are expected to contribute in developing wheat cultivars with improved stripe rust resistance. [ABSTRACT FROM AUTHOR]