WorldWideScience

Sample records for causing stripe rust

  1. EPIDEMIOLOGY AND CONTROL OF STRIPE RUST ON WHEAT

    Science.gov (United States)

    Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici, is one of the most important diseases of wheat worldwide. This review presents basic and recent information on stripe rust epidemiology, pathogen virulence changes and population structure, and movement of the pathogen in the Unit...

  2. Evidence for Increased Aggressiveness in a Recent Widespread Strain of Puccinia striiformis f. sp. tritici Causing Stripe Rust of Wheat

    DEFF Research Database (Denmark)

    Milus, Eugene A; Kristensen, Kristian; Hovmøller, Mogens S

    2009-01-01

    on virulence phenotype and amplified fragment length polymorphism. The objective of this research was to quantify differences in aggressiveness among isolates representative of the pre-2000 and post-2000 populations. Representative isolates were evaluated at low (10 to 18°C) and high (12 to 28°C) temperature...... regimes for latent period, lesion length, lesion width, lesion area, and spore production on adult plants of a susceptible wheat cultivar with no known genes for resistance to stripe rust. "New" isolates (since 2000) were significantly more aggressive than "old" isolates (before 2000) for all variables...... to the warm temperature regime for all variables. Based on these results and previously published models for stripe rust epidemics, recent severe stripe rust epidemics were most likely enhanced by the pathogen's increased aggressiveness, especially at higher temperature. Furthermore, these results demonstrate...

  3. Genome-wide association mapping for resistance to leaf and stripe rust in winter-habit hexaploid wheat landraces

    Science.gov (United States)

    Leaf rust, caused by Puccinia triticina (Pt), and stripe rust, caused by P. striiformis f. sp. tritici (Pst), are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst re...

  4. Genes for resistance to stripe rust on chromosome 2B and their application in wheat breeding

    Institute of Scientific and Technical Information of China (English)

    Peigao Luo; Xueyun Hu; Huaiyu Zhang; Zhenglong Ren

    2009-01-01

    Stripe rust,caused by Puccinia striiformis f.sp.tritici,is one of the most damaging diseases of wheat worldwide.Growing resistant cultivars is the most economic and environmental friendly way to control the disease.There are many resistance genes to stripe rust located on wheat chromosome 2B.Here,we propose a strategy to construct the recombinant wheat chromosome 2B with multiple resistances to stripe rust by making crosses between wheat lines or cultivars carrying Yr genes and using marker-assisted selection,based on the reported information about resistance spectrum,chromosomal location,and linked markers of the genes.Pyramiding the resistance genes on 2B would afford a valuable strategy to control the disease by cultivating varieties with durable resistance.The possibility,efficiency,and prospect of the suggested strategy are reviewed in the paper.

  5. Ultrastructure of Slow-Rusting Expression of Wheat to Stripe Rust

    Institute of Scientific and Technical Information of China (English)

    MA Qing; SHANG Hong-sheng; QIANG Lei; XIE Fang-qin; SUN Hui

    2005-01-01

    The ultrastructure of wheat cultivars with slow-rusting resistance expression to the stripe rust, Puccinia striiformis, was studied through TEM. The results show that slow-rusting has the same hypersensitive response characters with the low infection type resistance, but the mesophyll cell necrotized less in number, thereby only partially inhibiting the extension of rust fungus, and the fungus being inhibited and necrosed slighter in degree. Apart from the occurrence of hypersensitiveness, the response of the host cells in slow-rusting wheat cultivars to the infection of fungus also produces structural materials associated with defense reaction, but distinctly less than that in resistant cultivar. Thus, it is suggested that the slow-rusting resistance might have a similar mechanism with the low infection type resistance of race specificity,but with lower intensity.

  6. Identification of wheat-Thinopyrum intermedium alien disomic addition lines conferring resistance to stripe rust

    Science.gov (United States)

    Thinopyrum intermedium carries many useful traits for wheat genetic improvement. To identify genes conferring resistance to stripe rust caused by Puccinia striiformis f. sp. tritici in Zhong 4 (Z4) derived from a cross between common wheat and Th. intermedium, a cross was made between Z4 and a ‘Chin...

  7. Introgression of leaf rust and stripe rust resistance from Sharon goatgrass (Aegilops sharonensis Eig) into bread wheat (Triticum aestivum L.).

    Science.gov (United States)

    Millet, E; Manisterski, J; Ben-Yehuda, P; Distelfeld, A; Deek, J; Wan, A; Chen, X; Steffenson, B J

    2014-06-01

    Leaf rust and stripe rust are devastating wheat diseases, causing significant yield losses in many regions of the world. The use of resistant varieties is the most efficient way to protect wheat crops from these diseases. Sharon goatgrass (Aegilops sharonensis or AES), which is a diploid wild relative of wheat, exhibits a high frequency of leaf and stripe rust resistance. We used the resistant AES accession TH548 and induced homoeologous recombination by the ph1b allele to obtain resistant wheat recombinant lines carrying AES chromosome segments in the genetic background of the spring wheat cultivar Galil. The gametocidal effect from AES was overcome by using an "anti-gametocidal" wheat mutant. These recombinant lines were found resistant to highly virulent races of the leaf and stripe rust pathogens in Israel and the United States. Molecular DArT analysis of the different recombinant lines revealed different lengths of AES segments on wheat chromosome 6B, which indicates the location of both resistance genes.

  8. Characterization and mapping of cryptic alien introgression from Aegilops geniculata with new leaf rust and stripe rust resistance genes Lr57 and Yr40 in wheat.

    Science.gov (United States)

    Leaf rust and stripe rust are important foliar diseases of wheat worldwide. Leaf rust and stripe rust resistant introgression lines were developed by induced homoeologous chromosome pairing between wheat chromosome 5D and 5Mg of Aegilops geniculata (UgMg). Characterization of rust resistant BC2F5 a...

  9. Race-Specific Adult-Plant Resistance in Winter Wheat to Stripe Rust and Characterization of Pathogen Virulence Patterns.

    Science.gov (United States)

    Milus, Eugene A; Moon, David E; Lee, Kevin D; Mason, R Esten

    2015-08-01

    Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important disease of wheat in the Great Plains and southeastern United States. Growing resistant cultivars is the preferred means for managing stripe rust, but new virulence in the pathogen population overcomes some of the resistance. The objectives of this study were to characterize the stripe rust resistance in contemporary soft and hard red winter wheat cultivars, to characterize the virulence of P. striiformis f. sp. tritici isolates based on the resistances found in the cultivars, and to determine wheat breeders' perceptions on the importance and methods for achieving stripe rust resistance. Seedlings of cultivars were susceptible to recent isolates, indicating they lacked effective all-stage resistance. However, adult-plants were resistant or susceptible depending on the isolate, indicating they had race-specific adult-plant resistance. Using isolates collected from 1990 to 2013, six major virulence patterns were identified on adult plants of twelve cultivars that were selected as adult-plant differentials. Race-specific adult-plant resistance appears to be the only effective type of resistance protecting wheat from stripe rust in eastern United States. Among wheat breeders, the importance of incorporating stripe rust resistance into cultivars ranged from high to low depending on the frequency of epidemics in their region, and most sources of stripe rust resistance were either unknown or already overcome by virulence in the pathogen population. Breeders with a high priority for stripe rust resistance made most of their selections based on adult-plant reactions in the field, whereas breeders with a low priority for resistance based selections on molecular markers for major all-stage resistance genes.

  10. Identification and Validation of a Major Quantitative Trait Locus for Slow-rusting Resistance to Stripe Rust in Wheat

    Institute of Scientific and Technical Information of China (English)

    Xiaohua Cao; Jianghong Zhou; Xiaoping Gong; Guangyao Zhao; Jizeng Jia; Xiaoquan Qi

    2012-01-01

    Stripe (yellow) rust,caused by Puccinia striiformis Westend.f.sp.tritici Eriks (Pst),is one of the most important wheat (Triticum aestivum L.) diseases and causes significant yield losses.A recombinant inbred (RI) population derived from a cross between Yanzhan 1 and Xichang 76-9 cultivars was evaluated for resistance to wheat stripe rust strain CYR32 at both the seedling and adult plant stages.Four resistance quantitative trait loci (QTLs) were detected in this population,in which the major one,designated as Yrq1,was mapped on chromosome 2DS.The strategy of using the Brachypodium distachyon genome,wheat expressed sequence tags and a draft DNA sequences (scaffolds) of the D-genome (Aegilops tauschii Coss.) for the development of simple sequence repeat (SSR) markers was successfully used to identify 147 SSRs in hexaploid wheat.Of the 19 polymorphic SSRs in the RI population,17 SSRs were mapped in the homeologous group 2 chromosomes near Yrq1 region and eight SSRs were genetically mapped in the 2.7 cM region of Yrq1,providing abundant DNA markers for fine-mapping of Yrq1 and marker-assisted selection in wheat breeding program.The effectiveness of Yrq1 was validated in an independent population,indicating that this resistance QTL can be successfully transferred into a susceptible cultivar for improvement of stripe rust resistance.

  11. Molecular Screening and Resistance Evaluation of American Wheat Cultivars to Chinese Stripe Rust Races

    Institute of Scientific and Technical Information of China (English)

    BAI Yu-lu; ZHANG Chun-yu; SUN Quan; LIN Feng; CUI Na; XU Shi-chang; GAO Yang; XU Xiao-dan

    2010-01-01

    Stripe rust,caused by Puccinia striiformis f.sp.tritici,is one of the major diseases of wheat in China.In order to asses the resistance levels and existing Yr genes among 59 wheat cultivars (lines) from the Pacific Northwest (PNW) of the United States,to provide resistance resources for genetic improvement of wheat stripe rust resistance in China,59 wheat cultivars (lines) from PNW of the United States were infected by 3 mixed races of predominant Chinese stripe rust races CRY31,CRY32,and CRY33 to evaluate their resistance at seedling and adult plant stages,and screened with molecular markers tightly linked to currently effective all-stage resistance genes Yr10,Yr15 and adult plant resistance genes Yr18,Yr39.Of 59 American cultivars (lines),five cultivars (lines),Expresso,02W50076,ACS52610,WA008012,and WA00801833,had all-stage resistance,showing resistance to mixed races of CRY31,CRY32,and CRY33 at both seedling and adult plant stages.33 cultivars (lines) had adult plant resistance,only showing resistance to stripe rust at adult stage.Based on the molecular screening,none of the 59 PNW cultivars (lines) had the polymorphic bands of linked markers to Yr10.There were 12,33 and 29 cultivars (lines) which had polymorphic bands of linked markers to Yr15,Yr18 and Yr39,accounting for 20,55 and 49% of the 59 PNW cultivars (lines),respectively.All these results suggested that Yr15,Yr18 and Yr39 were widespread among PNW cultivars (cultivars) and could be utilized in Chinese wheat stripe rust resistance breeding.

  12. Integrated Management of Wheat Stripe Rust Caused by Puccinia striiformis f. sp. tritici in China%中国小麦条锈病综合治理理论与实践

    Institute of Scientific and Technical Information of China (English)

    陈万权; 康振生; 马占鸿; 徐世昌; 金社林; 姜玉英

    2013-01-01

    小麦条锈病是影响小麦安全生产的重要生物灾害。文中介绍了全国小麦锈病工作者通过60多年通力协作,对小麦条锈病综合治理理论和技术研究取得的显著成绩,系统揭示了中国小麦条锈病的越冬、越夏规律、菌源传播规律、病菌致病性变异途径以及品种抗病性“丧失”的规律与原因,发现中国小麦条锈病存在秋季菌源和春季菌源2大菌源基地。提出了“综合治理越夏异变区、持续控制冬季繁殖区和全面预防春季流行区”的病害源头治理策略,研发出小麦条锈病分子诊断、异地测报以及抗锈良种、药剂拌种、退麦改种、适期晚种和带药侦查、打点保面等一系列病害监测预警和关键防治技术,构建了以生物多样性利用为核心的中国小麦条锈病菌源基地综合治理技术体系,在生产上大规模推广应用,防病保产效果极其显著。文中并对病菌致病性变异机制、早期预警和越夏易变区生态治理等问题进行了讨论。%Wheat stripe (yellow) rust caused by Puccinia striiformis f. sp. tritici (Pst) is an important disaster in wheat production. A great deal of effort has been spent on the strategies and techniques of integrated management of wheat stripe rust for over six decades by a teamwork nationwide in China. It has been fully revealed that the over-summering and over-wintering areas of Pst inter-regional dispersal of inoculum, the way of virulence variation, and breakdown causation of wheat cultivar resistance. Based on the geographical conditions, wheat growth, occurrence and dispersal of disease etc, wheat stripe rust in China can be divided into three major zones, namely the autumn sources of inocula, the spring sources of inocula, and spring epidemic areas. A major strategy of headstream management has been put forward, i.e.‘integrated management of wheat stripe rust in the sources of inocula to protect wheat safe

  13. Evaluation of Pakistan wheat germplasms for stripe rust resistance using molecular markers

    Institute of Scientific and Technical Information of China (English)

    Sobia; TABASSUM; Muhammad; ASHRAF; CHEN; XianMing

    2010-01-01

    Wheat production in Pakistan is seriously constrained due to rust diseases and stripe rust (yellow) caused by Puccinia striiformis f.sp.tritici,which could limit yields.Thus development and cultivation of genetically diverse and resistant varieties is the most sustainable solution to overcome these diseases.The first objective of the present study was to evaluate 100 Pakistan wheat cultivars that have been grown over the past 60 years.These cultivars were inoculated at the seedling stage with two virulent stripe rust isolates from the United States and two from Pakistan.None of the wheat cultivars were resistant to all tested stripe rust isolates,and 16% of cultivars were susceptible to the four isolates at the seedling stage.The data indicated that none of the Pakistan wheat cultivars contained either Yr5 or Yr15 genes that were considered to be effective against most P.striiformis f.sp.tritici isolates from around the world.Several Pakistan wheat cultivars may have gene Yr10,which is effective against isolate PST-127 but ineffective against PST-116.It is also possible that these cultivars may have other previously unidentified genes or gene combinations.The second objective was to evaluate the 100 Pakistan wheat cultivars for stripe rust resistance during natural epidemics in Pakistan and Washington State,USA.It was found that a higher frequency of resistance was present under field conditions compared with greenhouse conditions.Thirty genotypes (30% of germplasms) were found to have a potentially high temperature adult plant (HTAP) resistance.The third objective was to determine the genetic diversity in Pakistan wheat germplasms using molecular markers.This study was based on DNA fingerprinting using resistance gene analog polymorphism (RGAP) marker analysis.The highest polymorphism detected with RGAP primer pairs was 40%,50% and 57% with a mean polymorphism of 36%.A total of 22 RGAP markers were obtained in this study.RGAP,simple sequence repeat (SSR) and

  14. Characterization of the Wheat Stripe Rust (Puccinia striiformis f. sp. tritici) Fungal Effector Candidate PEC6 and Its Corresponding Host Targets

    DEFF Research Database (Denmark)

    Liu, Changhai

    and understanding their mechanisms of action is fundamentally important to guide future fights against the stripe rust disease. In this PhD project, I studied the potential function of six stripe rust fungal effector candidates which are highly expressed in haustoria, by employing the Pseudomonas fluorescens Et......Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important fungal diseases on wheat worldwide and a serious threat to wheat production. Understanding the plant-microbe interaction mechanism is the basic step to assist future plant breeding aiming at increasing...... disease resistance. Based on the sequenced stripe rust fungus genome, several hundreds of small, secreted candidates for effector proteins are predicted. Effectors are believed to be pivotal for fungal pathogenicity with key roles in suppressing host defense. Thus, identifying key effectors...

  15. Comparative virulence and molecular diversity of stripe rust (Puccinia striiformis f. sp. tritici) collections from Pakistan and United States

    Science.gov (United States)

    Information on virulence and molecular diversity of Puccinia striiformis f. sp. tritici (Pst) is a pre-requisite for mitigating the substantial yield losses caused by the stripe rust pathogen in Pakistan, the United States and other countries of the world. This study was undertaken to analyze both v...

  16. Association analysis of SP-SNPs and Avr genes in Puccinia striiformis f. sp. tritici, the wheat stripe rust pathogen

    Science.gov (United States)

    Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust disease which is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics of wheat resistance to this disease, but few on avirulence of the pathogen...

  17. Cytological and molecular characterization of non-host resistance in Arabidopsis thaliana against wheat stripe rust.

    Science.gov (United States)

    Cheng, Yulin; Zhang, Hongchang; Yao, Juanni; Han, Qingmei; Wang, Xiaojie; Huang, Lili; Kang, Zhensheng

    2013-01-01

    Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive diseases of wheat worldwide. We report the use of the non-host plant Arabidopsis thaliana to identify the basis of resistance to Pst at the cytological and molecular levels. No visible symptoms were observed on Arabidopsis leaves inoculated with Pst. Microscopic observations showed that significantly reduced numbers of Pst urediospores had successfully achieved penetration in Arabidopsis compared with those in wheat. There were significant differences in the frequency of stomatal penetration but not in fungal growth among different Pst races in Arabidopsis. The fungus failed to successfully form haustoria in Arabidopsis and attempted infection induced an active response including accumulation of phenolic compounds and callose deposition in plant cells. A set of defence-related genes were also up regulated during the Pst infection. Compared with wild type plants, increased fungal growth was observed in an npr1-1 mutant and in NahG transformed plants, which both are insensitive to salicylic acid. However, treatment of Arabidopsis plants with cytochalasin B, an inhibitor of actin microfilament polymerization, did not increase susceptibility to Pst. Our results demonstrate that Arabidopsis can be used to study mechanisms of non-host resistance to wheat stripe rust, and highlight the significance of participation of salicylic acid in non-host resistance to rust fungi.

  18. Genetics of adult plant stripe rust resistance in CSP44, a selection from Australian wheat

    Indian Academy of Sciences (India)

    Renu Khanna; U. K. Bansal; R. G. Saini

    2005-12-01

    Wheat line CSP44, a selection from an Australian bread wheat cultivar Condor, has shown resistance to stripe rust in India since the last twenty years. Seedlings and adult plants of CSP44 showed susceptible infection types against stripe rust race 46S119 but displayed average terminal disease severity of 2.67 on adult plants against this race as compared to 70.33 of susceptible Indian cultivar, WL711. This suggests the presence of nonhypersensitive adult plant stripe rust resistance in the line CSP44. The evaluation of F1, F2 and F3 generations and F6 SSD families from the cross of CSP44 with susceptible wheat cultivar WL711 for stripe rust severity indicated that the resistance in CSP44 is based on two genes showing additive effect. One of these two genes is Yr18 and the second gene is not yet described.

  19. Molecular Mapping of a Gene for Resistance to Stripe Rust in Wheat Variety PIW138

    Institute of Scientific and Technical Information of China (English)

    YUE Yan-li; YAO Zhan-jun; REN Xin-xin; WANG Li

    2010-01-01

    Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is one of the most damaging diseases of common wheat(Triticum aestivum L.).Wheat variety PIW138 introduced from Pakistan is resistant to the currently prevailing Pst race CYR32 in China.In this study,the bulked segregant analysis(BSA)method and simple sequence repeat(SSR)markers were used to map the stripe rust resistance gene in PIW138.The resistant and susceptible DNA bulks were prepared from the segregating F2 population of the cross between Thatcher,a susceptible variety as the female parent,and PIW138 as the male parent.The segregation of resistant and susceptible F2 plants inoculated with CYR32 indicated that single dominant gene determined the reactions of PIW138 line and temporarily designated as YrP138.Total 200 SSR primers were screened,and 4 SSR markers,Xwmc52,Xbarc61,Xgwm268,and Xgwm153,on chromosome 1B were found to be polymorphic between the resistant and the susceptible DNA bulks as well as their parents.Genetic linkage was tested on the segregating F2 population with 259 plants,including 196 resistant and 63 susceptible plants.All 4 SSR markers were linked to the stripe rust resistance gene in PIW138.The genetic distances of Xwmc52,Xbarc61,Xgwm268,and Xgwm153to the resistance gene were 29.8,6.2,6.8,and 8.2 cM,respectively.

  20. Genome-Wide Association Mapping for Resistance to Leaf and Stripe Rust in Winter-Habit Hexaploid Wheat Landraces.

    Directory of Open Access Journals (Sweden)

    Albert Kertho

    Full Text Available Leaf rust, caused by Puccinia triticina (Pt, and stripe rust, caused by P. striiformis f. sp. tritici (Pst, are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst requires a constant search for new sources of resistance. Here we report a genome-wide association analysis of 567 winter wheat (Triticum aestivum landrace accessions using the Infinium iSelect 9K wheat SNP array to identify loci associated with seedling resistance to five races of Pt (MDCL, MFPS, THBL, TDBG, and TBDJ and one race of Pst (PSTv-37 frequently found in the Northern Great Plains of the United States. Mixed linear models identified 65 and eight significant markers associated with leaf rust and stripe rust, respectively. Further, we identified 31 and three QTL associated with resistance to Pt and Pst, respectively. Eleven QTL, identified on chromosomes 3A, 4A, 5A, and 6D, are previously unknown for leaf rust resistance in T. aestivum.

  1. Research investment implications of shifts in the global geography of wheat stripe rust.

    Science.gov (United States)

    Beddow, Jason M; Pardey, Philip G; Chai, Yuan; Hurley, Terrance M; Kriticos, Darren J; Braun, Hans-Joachim; Park, Robert F; Cuddy, William S; Yonow, Tania

    2015-01-01

    Breeding new crop varieties with resistance to the biotic stresses that undermine crop yields is tantamount to increasing the amount and quality of biological capital in agriculture. However, the success of genes that confer resistance to pests induces a co-evolutionary response that depreciates the biological capital embodied in the crop, as pests evolve the capacity to overcome the crop's new defences. Thus, simply maintaining this biological capital, and the beneficial production and economic outcomes it bestows, requires continual reinvestment in new crop defences. Here we use observed and modelled data on stripe rust occurrence to gauge changes in the geographic spread of the disease over recent decades. We document a significant increase in the spread of stripe rust since 1960, with 88% of the world's wheat production now susceptible to infection. Using a probabilistic Monte Carlo simulation model we estimate that 5.47 million tonnes of wheat are lost to the pathogen each year, equivalent to a loss of US$979 million per year. Comparing the cost of developing stripe-rust-resistant varieties of wheat with the cost of stripe-rust-induced yield losses, we estimate that a sustained annual research investment of at least US$32 million into stripe rust resistance is economically justified.

  2. Characterization of non-host resistance in broad bean to the wheat stripe rust pathogen

    Directory of Open Access Journals (Sweden)

    Cheng Yulin

    2012-06-01

    Full Text Available Abstract Background Non-host resistance (NHR confers plant species immunity against the majority of microbial pathogens and represents the most robust and durable form of plant resistance in nature. As one of the main genera of rust fungi with economic and biological importance, Puccinia infects almost all cereals but is unable to cause diseases on legumes. Little is known about the mechanism of this kind of effective defense in legumes to these non-host pathogens. Results In this study, the basis of NHR in broad bean (Vicia faba L. against the wheat stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst, was characterized. No visible symptoms were observed on broad bean leaves inoculated with Pst. Microscopic observations showed that successful location of stomata and haustoria formation were significantly reduced in Pst infection of broad bean. Attempted infection induced the formation of papillae, cell wall thickening, production of reactive oxygen species, callose deposition and accumulation of phenolic compounds in plant cell walls. The few Pst haustoria that did form in broad bean cells were encased in reactive oxygen and callose materials and those cells elicited cell death. Furthermore, a total of seven defense-related genes were identified and found to be up-regulated during the Pst infection. Conclusions The results indicate that NHR in broad bean against Pst results from a continuum of layered defenses, including basic incompatibility, structural and chemical strengthening of cell wall, posthaustorial hypersensitive response and induction of several defense-related genes, demonstrating the multi-layered feature of NHR. This work also provides useful information for further determination of resistance mechanisms in broad bean to rust fungi, especially the adapted important broad bean rust pathogen, Uromyces viciae-fabae, because of strong similarity and association between NHR of plants to unadapted pathogens and basal

  3. Genetic architecture of resistance to stripe rust in a global winter wheat germplasm collection

    Science.gov (United States)

    Virulence shifts in populations of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, are a major challenge to resistance breeding. The majority of known resistance genes are already ineffective against current races of Pst, necessitating the identification and intr...

  4. Genetic Architecture of Resistance to Stripe Rust in a Global Winter Wheat Germplasm Collection.

    Science.gov (United States)

    Bulli, Peter; Zhang, Junli; Chao, Shiaoman; Chen, Xianming; Pumphrey, Michael

    2016-01-01

    Virulence shifts in populations of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, are a major challenge to resistance breeding. The majority of known resistance genes are already ineffective against current races of Pst, necessitating the identification and introgression of new sources of resistance. Germplasm core collections that reflect the range of genetic and phenotypic diversity of crop species are ideal platforms for examining the genetic architecture of complex traits such as resistance to stripe rust. We report the results of genetic characterization and genome-wide association analysis (GWAS) for resistance to stripe rust in a core subset of 1175 accessions in the National Small Grains Collection (NSGC) winter wheat germplasm collection, based on genotyping with the wheat 9K single nucleotide polymorphism (SNP) iSelect assay and phenotyping of seedling and adult plants under natural disease epidemics in four environments. High correlations among the field data translated into high heritability values within and across locations. Population structure was evident when accessions were grouped by stripe rust reaction. GWAS identified 127 resistance loci that were effective across at least two environments, including 20 with significant genome-wide adjusted P-values. Based on relative map positions of previously reported genes and QTL, five of the QTL with significant genome-wide adjusted P-values in this study represent potentially new loci. This study provides an overview of the diversity of Pst resistance in the NSGC winter wheat germplasm core collection, which can be exploited for diversification of stripe rust resistance in breeding programs. PMID:27226168

  5. Stripe rust resistance genes in the UK winter wheat cultivar Claire.

    Science.gov (United States)

    Powell, N M; Lewis, C M; Berry, S T; Maccormack, R; Boyd, L A

    2013-06-01

    Stripe rust resistance in the winter wheat cultivar Claire had remained effective in the UK and Europe since its release in 1999 and consequently has been used extensively in wheat breeding programs. However, in 2012, reports indicated that this valuable resistance may now have been compromised. To characterise stripe rust resistance in Claire and determine which genes may still confer effective resistance a cross was made between Claire and the stripe rust susceptible cultivar Lemhi. A genetic linkage map, constructed using SSR, AFLP, DArT and NBS-AFLP markers had a total map length of 1,730 cM. To improve the definition of two quantitative trait loci (QTL) identified on the long arm of chromosome 2D further markers were developed from wheat EST. Stripe rust resistance was evaluated on adult plants under field and glasshouse conditions by measuring the extent of fungal growth and sporulation, percentage infection (Pi) and the necrotic/chlorotic responses of the plant to infection, infection type (IT). Four QTL contributing to stripe rust adult plant resistance (APR) were identified in Claire, QYr.niab-2D.1, QYr.niab-2D.2, QYr.niab-2B and QYr.niab-7B. For Pi QYr.niab-2D.1 explained up to 25.4 % of the phenotypic variation, QYr.niab-2D.2 up to 28.7 %, QYr.niab-2B up to 21.7 % and QYr.niab-7B up to 13.0 %. For IT the percentages of phenotypic variation explained were 23.4, 31.8, 17.2 and 12.6 %, respectively. In addition to the four QTL conferring APR in Claire, a race-specific, seedling expressed resistance gene was identified on chromosome 3B.

  6. Genetic Architecture of Resistance to Stripe Rust in a Global Winter Wheat Germplasm Collection.

    Science.gov (United States)

    Bulli, Peter; Zhang, Junli; Chao, Shiaoman; Chen, Xianming; Pumphrey, Michael

    2016-01-01

    Virulence shifts in populations of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, are a major challenge to resistance breeding. The majority of known resistance genes are already ineffective against current races of Pst, necessitating the identification and introgression of new sources of resistance. Germplasm core collections that reflect the range of genetic and phenotypic diversity of crop species are ideal platforms for examining the genetic architecture of complex traits such as resistance to stripe rust. We report the results of genetic characterization and genome-wide association analysis (GWAS) for resistance to stripe rust in a core subset of 1175 accessions in the National Small Grains Collection (NSGC) winter wheat germplasm collection, based on genotyping with the wheat 9K single nucleotide polymorphism (SNP) iSelect assay and phenotyping of seedling and adult plants under natural disease epidemics in four environments. High correlations among the field data translated into high heritability values within and across locations. Population structure was evident when accessions were grouped by stripe rust reaction. GWAS identified 127 resistance loci that were effective across at least two environments, including 20 with significant genome-wide adjusted P-values. Based on relative map positions of previously reported genes and QTL, five of the QTL with significant genome-wide adjusted P-values in this study represent potentially new loci. This study provides an overview of the diversity of Pst resistance in the NSGC winter wheat germplasm core collection, which can be exploited for diversification of stripe rust resistance in breeding programs.

  7. Molecular Mapping of Two Novel Stripe Rust Resistant Genes YrTp1 and YrTp2 in A-3 Derived from Triticum aestivum × Thinopyrum ponticum

    Institute of Scientific and Technical Information of China (English)

    YIN Xue-gui; SHANG Xun-wu; PANG Bin-shuang; SONG Jian-rong; CAO Shi-qin; LI Jin-chang; ZHANG Xue-yong

    2006-01-01

    Loss of variety resistance to stripe rust (Puccinia striiformis Westend f. sp. tritici) is an important factor causing massive periodical epidemic of rust in wheat production. Creation and development of new races of rust pathogen have led to serious crisis of resistance loss in widely planted varieties. This has quickened the search for new resistance resources.Molecular marker could facilitate the identification of the location of novel genes. A line A-3 with high resistance(immune) to currently epidemic yellow rust races (CY29, 31, 32) was screened out in offspring of Triticum aestivum ×Thinopyrum ponticum. Segregation in F2 and BC1 populations indicated that the resistance was controlled by two independent genes: one dominant and one recessive. SSR markers were employed to map the two resistant genes in the F2 and BC1 populations. A marker WMC477-167bp located on 2BS was linked to the dominant gene with genetic distance of 0.4 cM. Another marker WMC364-208bp located on 7BS was linked to the recessive-resistant gene with genetic distance of 5.8 cM. The two genes identified in this paper might be two novel stripe rust resistant genes, which were temporarily designated as YrTpl and YrTp2, respectively. The tightly linking markers facilitate transfer of the two resistant genes into the new varieties to control epidemic of yellow rust.

  8. Genetic Analysis and Molecular Mapping of a Stripe Rust Resistance Gene YrH9014 in Wheat Line H9014-14-4-6-1

    Institute of Scientific and Technical Information of China (English)

    MA Dong-fang; HOU Lu; TANG Ming-shuang; WANG Hai-ge; LI Qiang; JING Jin-xue

    2013-01-01

    Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most widespread and destructive wheat diseases in many wheat-growing regions of the world. The winter wheat translocation line H9014-14-4-6-1 has all stage resistance. To identify stripe rust resistance genes, the segregating populations were developed from the cross between H9014-14-4-6-1 and Mingxian 169 (a wheat cultivar susceptible to all Pst races identified in China). The seedlings of the parents and F1 plants, F2, F3 and BC1 generations were tested with Pst races under controlled greenhouse conditions. Two genes for resistance to stripe rust were identified, one dominant gene conferred resistance to SUN11-4, temporarily designated YrH9014 and the other recessive gene conferred resistance to CYR33. The bulked segregant analysis and simple sequence repeat (SSR) markers were used to identify polymorphic markers associated with YrH9014. Seven polymorphic SSR markers were used to genotype the F2 population inoculated with SUN11-4. A linkage map was constructed according to the genotypes of seven SSR markers and resistance gene. The molecular map spanned 24.3 cM, and the genetic distance of the two closest markers Xbarc13 and Xbarc55 to gene locus was 1.4 and 3.6 cM, respectively. Based on the position of SSR marker, the resistance gene YrH9014 was located on chromosome arm 2BS. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xbarc13 indicated that YrH9014 was located on chromosome 2B. Based on chromosomal location, the reaction patterns and pedigree analysis, YrH9014 should be a novel resistance gene to stripe rust. This new gene and flanking markers got from this study should be useful for marker-assisted selection (MAS) in breeding programs for stripe rust.

  9. Appraisal of wheat germplasm for adult plant resistance against stripe rust

    Directory of Open Access Journals (Sweden)

    Saleem Kamran

    2015-12-01

    Full Text Available The resurgence of wheat stripe rust is of great concern for world food security. Owing to resistance breakdown and the appearance of new virulent high-temperature adapted races of Puccinia striiformis f. sp. tritici (Pst, many high yielding commercial varieties in the country lost their yield potential. Searching for new sources of resistance is the best approach to mitigate the problem. Quantitative resistance (partial or adult plant or durable resistance is reported to be more stable than race specific resistance. In the current perusal, a repertoire of 57 promising wheat lines along with the KLcheck line Morocco, developed through hybridisation and selection of local and international lines with International Maize and Wheat Improvement Center (CIMMYT origin, were evaluated under natural field conditions at Nuclear Institute for Agriculture and Biology (NIAB during the 2012−2013 and 2013−2014 time periods. Final rust severity (FRS, the area under the rust progress curve (AURPC, the relative area under the rust progress curve (rAURPC, and the coefficient of infection (CI were unraveled to infer the level of quantitative resistance. Final rust severity was recorded when the susceptible check exhibited 100% severity. There were 21 lines which were immune (no disease, 16 which were resistant, five moderately resistant, two resistant-to-moderately resistant, one moderately resistant-to-moderately susceptible, 5 moderately susceptible-to-susceptible, one moderately susceptible, and six exhibited a susceptible response. Nevertheless, 51 lines exhibited a high level of partial resistance while the three lines, NW-5-1212-1, NW-7-30-1, and NW-7-5 all showed a moderate level of partial resistance based on FRS, while 54 lines, on the basis of AURPC and rAURPC, were identified as conferring a high level of partial resistance. Moreover, adult plant resistance was conferred by 47 wheat lines, based on CI value. It was striking that, 13 immune lines

  10. Molecular mapping of a stripe rust resistance gene in Chinese wheat cultivar Mianmai 41

    Institute of Scientific and Technical Information of China (English)

    REN Yong; LI Sheng-rong; WEI Yu-ming; ZHOU Qiang; DU Xiao-ying; HE Yuan-jiang; ZHENG You-liang

    2015-01-01

    Stripe rust, caused by Puccinia stri formis f. sp. tritici (Pst), is one of the most damaging diseases of wheat. Chinese wheat cultivar Mianmai 41 showed high resistance against most of the prevailing Pst races in China. Genetic analysis of the F1, F2 and F2:3 populations from a cross between Mianmai 41 and a susceptible line Mingxian 169 indicated that resistance to Pst race CYR32 was conferred by a single dominant gene, temporarily designated as YrMY41. Molecular marker analysis placed the gene on chromosome 1B near the centromere. Six co-dominant genomic SSR markers Xwmc329, Xwmc406, Xgwm18, Xgwm131, Xgwm413, and Xbarc312, and one STS marker Xwe173 linked with the resistance gene. The two closest lfanking SSR markers were Xgwm18 and Xwmc406, with genetic distances of 2.0 and 4.9 cM, respectively. A seedling test with 29 Pst isolates indicated the reaction patterns of Mianmai 41 were different from those of lines carrying Yr3, Yr9, Yr10, Yr15, Yr26, and YrCH42 on chromosome 1B. Al elic tests indicated that YrMY41 is likely a new al ele at Yr26 locus.

  11. Inheritance and Molecular Mapping of Stripe Rust Resistance Gene Yr88375 in Chinese Wheat Line Zhongliang 88375

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Stripe rust is one of the most important diseases of wheat worldwide. Inheritance of stripe rust resistance and mapping of resistance gene with simple sequence repeat (SSR) markers are studied to formulate efficient strategies for breeding cultivars resistant to stripe rust. Zhongliang 88375, a common wheat line, is highly resistant to all three rusts of wheat in China. The gene conferring rust disease was deduced originating from Elytrigia intermedium. Genetic analysis of Zhongliang 88375 indicated that the resistance to PST race CYR31 was controlled by a single dominant gene, temporarily designated as Yr88375. To molecular map Yr88375, a F2 segregating population consisting of 163 individuals was constructed on the basis of the hybridization between Zhongliang 88375 and a susceptible wheat line Mingxian 169; 320 SSR primer pairs were used for analyzing the genetic linkage relation. Six SSR markers, Xgwm335, Xwmc289, Xwmc810, Xgdm116, Xbarc59, and Xwmc783, are linked to Yr88375 as they were all located on chromosome 5BL. Yr88375 was also located on that chromosome arm, closely linked to Xgdmll6 and Xwmc810 with genetic distances of 3.1 and 3.9 cM, respectively. The furthest marker Xwmc783 was 13.5 cM to Yr88375. Hence, pedigree analysis of Zhongliang 88375 combined with SSR markers supports the conclusion that the highly resistance gene Yr88375 derived from Elytrigia intermedium is a novel gene for resistance to stripe rust in wheat. It could play an important role in wheat breeding programs for stripe rust resistance.

  12. Yr32 for resistance to stripe (yellow) rust present in the wheat cultivar Carstens V

    DEFF Research Database (Denmark)

    Eriksen, L.; Afshari, F.; Christiansen, M.J.;

    2004-01-01

    in Carstens V. For this latter purpose, stripe rust response data from both seedling and field tests on a doubled haploid population consisting of 77 lines were compared to an available molecular map for the same lines using a non-parametric quantitative trait loci (QTL) analysis. Results obtained in Denmark...... in this chromosome arm, it was designated Yr32. Further QTLs originating from Senat were located in chromosomes 1BL, 4D, and 7DS and from Savannah on 5B, but it was not possible to characterize them as unique resistance genes in any definitive way. Yr32 was detected in several wheats, including the North American...

  13. 黄淮麦区小麦资源中高温抗条锈性品种的筛选%Screening of Wheat Cultivars for High Temperature Resistance to Stripe Rust from Wheat Resources in Huanghuai Growth Area

    Institute of Scientific and Technical Information of China (English)

    杨炜迪; 陈宏灏; 王美南

    2008-01-01

    [Objective] The study aimed to screen wheat cultivars with high temperature resistance to stripe rust from the wheat resources in Huanghuai growth area. [Method] Seedlings of 165 wheat cultivars from Huanghuai growth area were identified by wheat stripe rust under high temperature; then the wheat cultivars showing stripe rust at seedling stage were further used to identify the same resistance in field. [Results] 13 cultivars were proved to be stripe rust resistant under high temperature, and the expression stages of stripe rust in the 13 cultivars were revealed. The field identification results confirmed the identification results at seedling stage via inoculation of mixed stripe rust of physiological races. The stripe resistances of wheat cultivars were also proved to be non-race-specific. [Conclusion] Wheat resources in Huanghuai growth area are abundant in wheat cultivars with high temperature resistance to stripe rust.

  14. A novel fungal hyperparasite of Puccinia striiformis f. sp. tritici, the causal agent of wheat stripe rust.

    Directory of Open Access Journals (Sweden)

    Gangming Zhan

    Full Text Available Puccinia striiformis f. sp. tritici (Pst, the causal fungus of wheat stripe rust, was previously reported to be infected by Lecanicillium lecanii, Microdochium nivale and Typhula idahoensis. Here, we report a novel hyperparasite on Pst. This hyperparasitic fungus was identified as Cladosporium cladosporioides (Fresen. GA de Vries based on morphological characteristics observed by light and scanning electron microscopy together with molecular data. The hyperparasite reduced the production and viability of urediniospores and, therefore, could potentially be used for biological control of wheat stripe rust.

  15. Inheritance and Molecular Mapping of an All-Stage Stripe Rust Resistance Gene Derived from the Chinese Common Wheat Landrace "Yilongtuomai".

    Science.gov (United States)

    Wu, Xue-Lian; Wang, Jian-Wei; Cheng, Yu-Kun; Ye, Xue-Ling; Li, Wei; Pu, Zhi-En; Jiang, Qian-Tao; Wei, Yu-Ming; Deng, Mei; Zheng, You-Liang; Chen, Guo-Yue

    2016-09-01

    Yellow or stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating foliar disease that affects common wheat (Triticum aestivum L.) around the world. In China, common wheat landraces are potential sources of disease and abiotic stress resistance genes for wheat improvement. Yilongtuomai (YL), a wheat landrace from Yilong County, Sichuan Province, shows high levels of resistance against most Chinese Pst races. In this study, the resistance of YL to stripe rust disease was examined in detail. Parent strains, YL and Taichung 29, a variety susceptible to Pst race CYR32, and their F1, F2, and F2:3 offspring, were inoculated with CYR32 during the seedling stage in the field or adult-plant stage in the greenhouse. Results indicated that resistance to CYR32 in YL is conferred by a single dominant gene, designated YrYL The segregating F2 population (352 plants), was analyzed in terms of its resistance locus using simple sequence repeats (SSRs), resistance gene analog polymorphisms (RGAPs), and sequence-related amplified polymorphism (SRAP). A linkage group of 6 SSRs, 2 RGAPs, and 1 SRAP was constructed for the YrYL gene. Using the identified SSRs associated with physical mapping of RGAP using Chinese Spring nullisomic-tetrasomic stocks, the YrYL gene was localized to the short arm of chromosome 7D. The gene was flanked by 1 SSR marker, Xbarc92, and 1 RGAP marker, CLRRfor/Ptokin4, at genetic distances of 5.35 and 9.86 cM, respectively. The YrYL gene was compared to other stripe rust resistance genes reported on chromosome 7D by evaluating its reaction patterns to CYR32 and its pedigree relationship. Our results suggest that the YrYL gene is a new stripe rust resistance gene. PMID:27208148

  16. Inheritance and Molecular Mapping of an All-Stage Stripe Rust Resistance Gene Derived from the Chinese Common Wheat Landrace "Yilongtuomai".

    Science.gov (United States)

    Wu, Xue-Lian; Wang, Jian-Wei; Cheng, Yu-Kun; Ye, Xue-Ling; Li, Wei; Pu, Zhi-En; Jiang, Qian-Tao; Wei, Yu-Ming; Deng, Mei; Zheng, You-Liang; Chen, Guo-Yue

    2016-09-01

    Yellow or stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating foliar disease that affects common wheat (Triticum aestivum L.) around the world. In China, common wheat landraces are potential sources of disease and abiotic stress resistance genes for wheat improvement. Yilongtuomai (YL), a wheat landrace from Yilong County, Sichuan Province, shows high levels of resistance against most Chinese Pst races. In this study, the resistance of YL to stripe rust disease was examined in detail. Parent strains, YL and Taichung 29, a variety susceptible to Pst race CYR32, and their F1, F2, and F2:3 offspring, were inoculated with CYR32 during the seedling stage in the field or adult-plant stage in the greenhouse. Results indicated that resistance to CYR32 in YL is conferred by a single dominant gene, designated YrYL The segregating F2 population (352 plants), was analyzed in terms of its resistance locus using simple sequence repeats (SSRs), resistance gene analog polymorphisms (RGAPs), and sequence-related amplified polymorphism (SRAP). A linkage group of 6 SSRs, 2 RGAPs, and 1 SRAP was constructed for the YrYL gene. Using the identified SSRs associated with physical mapping of RGAP using Chinese Spring nullisomic-tetrasomic stocks, the YrYL gene was localized to the short arm of chromosome 7D. The gene was flanked by 1 SSR marker, Xbarc92, and 1 RGAP marker, CLRRfor/Ptokin4, at genetic distances of 5.35 and 9.86 cM, respectively. The YrYL gene was compared to other stripe rust resistance genes reported on chromosome 7D by evaluating its reaction patterns to CYR32 and its pedigree relationship. Our results suggest that the YrYL gene is a new stripe rust resistance gene.

  17. Genetics and Molecular Mapping of a High-Temperature Resistance Gene to Stripe Rust in Seeding-Stage in Winter Wheat Cultivar Lantian 1

    Institute of Scientific and Technical Information of China (English)

    MA Dong-fang; JING Jin-xue; HOU Dong-yuan; LI Qiang; ZHOU Xin-li; DU Jiu-yuan; and LU Qing-lin

    2013-01-01

    Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a severe foliar disease of common wheat (Triticum aestivum L.) in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene(s) for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 (M169). Seedlings of the parents, and F1, F2 and F2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat (SSR) techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively;and the two markers in combination could distinguish the alleles at the resistance locus in 97.9%of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.

  18. 无人机遥感监测小麦条锈病初探%Preliminary study on monitoring wheat stripe rust with using UAV

    Institute of Scientific and Technical Information of China (English)

    冷伟锋; 王海光; 胥岩; 马占鸿

    2012-01-01

    To explore the potential application of unmanned aerial vehicle (UAV) on monitoring wheat stripe rust caused by Puccinia striiformis f. sp. tritici, the image of wheat plots was obtained at the UVA platform. Correlation analyses between disease indexes of stripe rust and four kinds of the reflectance, i. e. the canopy reflectance and the reflectances in red, green and blue band extracted from the image, were conducted. The estimation models between disease indexes and each kind of the reflectance were built using linear regression method. The results showed that there was an extremely significant difference between the reflectances of diseased wheat plots and healthy plots. Disease indexes had positive correlation with the four kinds of the reflectances. Disease index was best fitted by the model with the reflectance in red band as independent variable. The diseased and the healthy areas in the UAV image were distinguished by using ISODATA method. The results indicated that UVA-based monitoring of wheat stripe rust was feasible and image analysis technologies could play a potential role in the monitoring process.

  19. Molecular mapping of a stripe rust resistance gene in wheat line C51

    Indian Academy of Sciences (India)

    Jianmin Zheng; Zehong Yan; Li Zhao; Shizhao Li; Zengyan Zhang; Resewarne Garry; Wuyun Yang; Zongjun Pu

    2014-08-01

    Stripe rust, a major disease in areas where cool temperatures prevail, can strongly influence grain yield. To control this disease, breeders have incorporated seedling resistance genes from a variety of sources outside the primary wheat gene pool. The wheat line C51, introduced from the International Center for Agricultural Research in the Dry Areas (ICARDA), Syria, confers resistance to all races of Puccinia striiformis f. sp. tritici (PST) in China. To map the resistant gene(s) against stripe rust in wheat line C51, 212 F8 recombinant inbred lines (RILs) derived from the cross X440 × C51 were inoculated with Chinese PST race CYR33 (Chinese yellow rust, CYR) in the greenhouse. The result showed that C51 carried a single dominant gene for resistance (designated YrC51) to CYR33. Simple sequence repeat (SSR) and resistance gene-analogue polymorphism (RGAP) markers that were polymorphic between the parents were used for genotyping the 212 F8 RILs. YrC51 was closely linked to two SSR loci on chromosome 2BS with genetic distances of 5.1 cM (Xgwm429) and 7.2 cM (Xwmc770), and to three RGAP markers C51R1 (XLRR For / NLRR For), C51R2 (CLRR Rev / Cre3LR-F) and C51R3 (Pto kin4/ NLRRINV2) with genetic distances of 5.6, 1.6 and 9.2 cM, respectively. These RGAP-linked markers were then converted into STS markers.Among them, one STS marker, C51STS-4, was located at a genetic distance of 1.4 cM to YrC51 and was closely associated with resistance when validated in several populations derived from crosses between C51 and Sichuan cultivars. The results indicated that C51STS-4 can be used for marker assisted selection (MAS) and would facilitate the pyramiding of YrC51 with other genes for stripe rust resistance.

  20. Molecular cytogenetic characterization of a new wheat Secale africanum 2Ra(2D) substitution line for resistance to stripe rust

    Indian Academy of Sciences (India)

    Mengping Lei; Guangrong Li; Sufen Zhang; Cheng Liu; Zujun Yang

    2011-08-01

    A stable, highly fertile wheat Secale africanum substitution line LF24, derived from the F7 generation of a cross between Mianyang11 (MY11) and Triticum durum, S. africanum amphiploid (YF) was identified through molecular cytogenetic analysis. Application of C-banding, in situ hybridization and molecular markers analysis showed that LF24 was a wheat S. africanum 2Ra(2D) substitution line. When inoculated with stripe rust isolates, T. durum and MY11 were highly susceptible, while S. africanum, YF and LF24 were immune. It is confirmed through molecular cytogenetic analysis that the stripe rust resistance of LF24 was derived from S. africanum chromosome 2Ra. We compared the banding patterns and disease resistance of reported chromosomes 2R from different S. cereale introduced into wheat background, and found that there was new stripe rust resistance gene(s) on S. africanum 2Ra. LF24 is a new substitution line which can be used as stripe rust resistant source in wheat improvement.

  1. Study of the Adult-Plant Resistance at Different Growth Stages to Stripe Rust in Wheat

    Institute of Scientific and Technical Information of China (English)

    ZHAO Huan-huan; R P Singh; J Huerta-Espino; YANG Zuo-min; SUN Qi-xin

    2005-01-01

    Components of resistance were investigated for five adult-plant resistant (APR) wheat (Triticum aestivum) cultivars at six growth stages and two temperatures in the greenhouse, and disease progress in a field trial. Chinese cultivar Chuanyu 12displayed high to intermediate infection type (IT) in the greenhouse but was highly resistant in the field. Weebill showed an intermediate IT in the greenhouse and also in the field. Chpaio, Tukuru and Saar, known to carry combinations of Yr18and 2-3 additional minor genes, were highly resistant in both experiments. Greenhouse experiments indicated that the lower IT of APR cultivars initiated at tillering stage. Latent periods (LP) for APR cultivars were generally longer as the growth stage progressed. We conclude that APR to stripe rust can be best characterized in field trials although significant correlations are seen between field severity and IT and LP measured in the greenhouse.

  2. Genetic analysis and location of gene for resistance to stripe rust in wheat international differential host Strubes Dickkopf

    Indian Academy of Sciences (India)

    Feng Jing; Xu Jiao-Jiao; Lin Rin-Ming; He Yue-Qiu; Xu Shi-Chang

    2013-08-01

    Strubes Dickkopf is the sixth differential in the world set for wheat stripe (yellow) rust. It is very important to clarify its genetic character of resistance to stripe rust and to develop the molecular markers linked to resistance genes. The NIL Taichung 29*6/Strubes Dickkopf, which was obtained by Strubes Dickkopf as the gene donor and Taichung 29 as the genetic background through backcross breeding, was crossed with the recurrent parent Taichung 29, inbred, and backcrossed to obtain the F1, F2 and BC1 population. The genetic analysis of the cross Taichung 29/(Taichung 29*6/Strubes Dickkopf) was assessed by inoculating the rust race CYR26 at seedling stage. Bulked segregant analysis (BSA) and F2 segregation analysis were used for detecting polymorphic primers to locate the gene. The resistance of the NIL Taichung 29*6/Strubes Dickkopf to CYR26 was controlled by a single dominant gene, named YrSD. The primer pair Xbarc59 on 5B was linked to YrSD and the genetic distance between Xbarc59 and YrSD was 2.4 cM. The molecular marker Xbarc59 closely linked to the gene YrSD could be used in marker-assisted selection for resistance to stripe rust in wheat breeding programmes.

  3. Characterization of protein kinase PsSRPKL, a novel pathogenicity factor in the wheat stripe rust fungus.

    Science.gov (United States)

    Cheng, Yulin; Wang, Xiaojie; Yao, Juanni; Voegele, Ralf T; Zhang, Yanru; Wang, Wumei; Huang, Lili; Kang, Zhensheng

    2015-08-01

    As in other eukaryotes, protein kinases (PKs) are generally evolutionarily conserved and play major regulatory roles in plant pathogenic fungi. Many PKs have been proven to be important for pathogenesis in model fungal plant pathogens, but little is currently known about their roles in the pathogenesis of cereal rust fungi, devastating pathogens in agriculture worldwide. Here, we report on an in planta highly induced PK gene PsSRPKL from the wheat stripe rust fungus Puccinia striiformis f. sp. tritici (Pst), one of the most important cereal rust fungi. PsSRPKL belongs to a group of PKs that are evolutionarily specific to cereal rust fungi. It shows a high level of intraspecies polymorphism in the kinase domains and directed green fluorescent protein chimers to plant nuclei. Overexpression of PsSRPKL in fission yeast induces aberrant cell morphology and a decreased resistance to environmental stresses. Most importantly, PsSRPKL is proven to be an important pathogenicity factor responsible for fungal growth and responses to environmental stresses, therefore contributing significantly to Pst virulence in wheat. We hypothesize that cereal rust fungi have developed specific PKs as pathogenicity factors for adaptation to their host species during evolution. Thus, our findings provide significant insights into pathogenicity and virulence evolution in cereal rust fungi.

  4. Transcriptome Analysis Provides Insights into the Mechanisms Underlying Wheat Plant Resistance to Stripe Rust at the Adult Plant Stage.

    Directory of Open Access Journals (Sweden)

    Yingbin Hao

    Full Text Available Stripe rust (or yellow rust, which is caused by Puccinia striiformis f. sp. tritici (Pst, is one of the most devastating wheat diseases worldwide. The wheat cultivar Xingzi 9104 (XZ is an elite wheat germplasm that possesses adult plant resistance (APR, which is non-race-specific and durable. Thus, to better understand the mechanism underlying APR, we performed transcriptome sequencing of wheat seedlings and adult plants without Pst infection, and a total of 157,689 unigenes were obtained as a reference. In total, 2,666, 783 and 2,587 differentially expressed genes (DEGs were found to be up- or down-regulated after Pst infection at 24, 48 and 120 hours post-inoculation (hpi, respectively, based on a comparison of Pst- and mock-infected plants. Among these unigenes, the temporal pattern of the up-regulated unigenes exhibited transient expression patterns during Pst infection, as determined through a Gene Ontology (GO enrichment analysis. In addition, a Kyoto Encyclopedia of Genes and Genomes (KEGG pathway analysis showed that many biological processes, including phenylpropanoid biosynthesis, reactive oxygen species, photosynthesis and thiamine metabolism, which mainly control the mechanisms of lignification, reactive oxygen species and sugar, respectively, are involved in APR. In particular, the continuous accumulation of reactive oxygen species may potentially contribute to the ability of the adult plant to inhibit fungal growth and development. To validate the bioinformatics results, 6 candidate genes were selected for further functional identification using the virus-induced gene silencing (VIGS system, and 4 candidate genes likely contribute to plant resistance against Pst infection. Our study provides new information concerning the transcriptional changes that occur during the Pst-wheat interaction at the adult stage and will help further our understanding of the detailed mechanisms underlying APR to Pst.

  5. Transcriptome Analysis Provides Insights into the Mechanisms Underlying Wheat Plant Resistance to Stripe Rust at the Adult Plant Stage.

    Science.gov (United States)

    Hao, Yingbin; Wang, Ting; Wang, Kang; Wang, Xiaojie; Fu, Yanping; Huang, Lili; Kang, Zhensheng

    2016-01-01

    Stripe rust (or yellow rust), which is caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating wheat diseases worldwide. The wheat cultivar Xingzi 9104 (XZ) is an elite wheat germplasm that possesses adult plant resistance (APR), which is non-race-specific and durable. Thus, to better understand the mechanism underlying APR, we performed transcriptome sequencing of wheat seedlings and adult plants without Pst infection, and a total of 157,689 unigenes were obtained as a reference. In total, 2,666, 783 and 2,587 differentially expressed genes (DEGs) were found to be up- or down-regulated after Pst infection at 24, 48 and 120 hours post-inoculation (hpi), respectively, based on a comparison of Pst- and mock-infected plants. Among these unigenes, the temporal pattern of the up-regulated unigenes exhibited transient expression patterns during Pst infection, as determined through a Gene Ontology (GO) enrichment analysis. In addition, a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that many biological processes, including phenylpropanoid biosynthesis, reactive oxygen species, photosynthesis and thiamine metabolism, which mainly control the mechanisms of lignification, reactive oxygen species and sugar, respectively, are involved in APR. In particular, the continuous accumulation of reactive oxygen species may potentially contribute to the ability of the adult plant to inhibit fungal growth and development. To validate the bioinformatics results, 6 candidate genes were selected for further functional identification using the virus-induced gene silencing (VIGS) system, and 4 candidate genes likely contribute to plant resistance against Pst infection. Our study provides new information concerning the transcriptional changes that occur during the Pst-wheat interaction at the adult stage and will help further our understanding of the detailed mechanisms underlying APR to Pst.

  6. Microtubule Polymerization Functions in Hypersensitive Response and Accumulation of H2O2 in Wheat Induced by the Stripe Rust.

    Science.gov (United States)

    Wang, Juan; Wang, Yang; Liu, Xinjie; Xu, Yuanliu; Ma, Qing

    2016-01-01

    The plant cytoskeleton, including microtubules and microfilaments, is one of the important factors in determining the polarity of cell division and growth, as well as the interaction of plants with invading pathogens. In defense responses of wheat against the stripe rust (Puccinia striiformis f. sp. tritici) infection, hypersensitive response is the most crucial event to prevent the spread of pathogens. In order to reveal the effect of microtubules on the hypersensitive cell death and H2O2 accumulation in the interaction of wheat (Triticum aestivum) cv. Suwon 11 with an incompatible race, CYR23, wheat leaves were treated with microtubule inhibitor, oryzalin, before inoculation. The results showed that the frequency of infection sites with hypersensitive response occurrence was significantly reduced, and hypersensitive cell death in wheat leaves was suppressed compared to the control. In addition, the frequency and the incidence of infected cells with H2O2 accumulation were also reduced after the treatment with oryzalin. Those results indicated that microtubules are related to hypersensitive response and H2O2 accumulation in wheat induced by the stripe rust, and depolymerization of microtubules reduces the resistance of plants to pathogen infection in incompatible interaction, suggesting that microtubules play a potential role in the expression of resistance of wheat against the stripe rust fungus. PMID:27610380

  7. Microtubule Polymerization Functions in Hypersensitive Response and Accumulation of H2O2 in Wheat Induced by the Stripe Rust

    Directory of Open Access Journals (Sweden)

    Juan Wang

    2016-01-01

    Full Text Available The plant cytoskeleton, including microtubules and microfilaments, is one of the important factors in determining the polarity of cell division and growth, as well as the interaction of plants with invading pathogens. In defense responses of wheat against the stripe rust (Puccinia striiformis f. sp. tritici infection, hypersensitive response is the most crucial event to prevent the spread of pathogens. In order to reveal the effect of microtubules on the hypersensitive cell death and H2O2 accumulation in the interaction of wheat (Triticum aestivum cv. Suwon 11 with an incompatible race, CYR23, wheat leaves were treated with microtubule inhibitor, oryzalin, before inoculation. The results showed that the frequency of infection sites with hypersensitive response occurrence was significantly reduced, and hypersensitive cell death in wheat leaves was suppressed compared to the control. In addition, the frequency and the incidence of infected cells with H2O2 accumulation were also reduced after the treatment with oryzalin. Those results indicated that microtubules are related to hypersensitive response and H2O2 accumulation in wheat induced by the stripe rust, and depolymerization of microtubules reduces the resistance of plants to pathogen infection in incompatible interaction, suggesting that microtubules play a potential role in the expression of resistance of wheat against the stripe rust fungus.

  8. Microtubule Polymerization Functions in Hypersensitive Response and Accumulation of H2O2 in Wheat Induced by the Stripe Rust.

    Science.gov (United States)

    Wang, Juan; Wang, Yang; Liu, Xinjie; Xu, Yuanliu; Ma, Qing

    2016-01-01

    The plant cytoskeleton, including microtubules and microfilaments, is one of the important factors in determining the polarity of cell division and growth, as well as the interaction of plants with invading pathogens. In defense responses of wheat against the stripe rust (Puccinia striiformis f. sp. tritici) infection, hypersensitive response is the most crucial event to prevent the spread of pathogens. In order to reveal the effect of microtubules on the hypersensitive cell death and H2O2 accumulation in the interaction of wheat (Triticum aestivum) cv. Suwon 11 with an incompatible race, CYR23, wheat leaves were treated with microtubule inhibitor, oryzalin, before inoculation. The results showed that the frequency of infection sites with hypersensitive response occurrence was significantly reduced, and hypersensitive cell death in wheat leaves was suppressed compared to the control. In addition, the frequency and the incidence of infected cells with H2O2 accumulation were also reduced after the treatment with oryzalin. Those results indicated that microtubules are related to hypersensitive response and H2O2 accumulation in wheat induced by the stripe rust, and depolymerization of microtubules reduces the resistance of plants to pathogen infection in incompatible interaction, suggesting that microtubules play a potential role in the expression of resistance of wheat against the stripe rust fungus.

  9. Wheat rusts in the United States in 2015

    Science.gov (United States)

    In 2015 wheat stripe rust caused by Puccinia striiformis f. sp. graminis was widespread throughout the United States. Cool temperatures and abundant rainfall in the southern Great Plains allowed stripe rust to become widely established and spread throughout the Great Plains and eastern United States...

  10. First Report of Orange Rust of Sugarcane Caused by Puccinia kuehnii in Ivory Coast and Cameroon

    Science.gov (United States)

    Orange rust of sugarcane caused by Puccinia kuehnii was detected in Florida in 2007. It was hypothesized that the pathogen originated from Africa because brown rust of sugarcane (syn. common rust) was introduced to the Western Hemisphere from Africa. Requests for rust infected sugarcane samples were...

  11. Development and identification of wheat mutants with some new root characteristics and resistance to stripe rust

    International Nuclear Information System (INIS)

    Wheat production is greatly affected by biotic factors and abiotic stresses. Therefore, it is necessary to develop some new wheat lines with disease resistance, abiotic stress tolerance and other characteristics using mutation techniques and biotechnology. In this study, twelve wheat materials with different backgrounds were tested for root characteristics in vitro and in the field. The results demonstrated that the intermediate materials derived from interspecies crosses between common wheat and Th.intermedium such as Zhong 4 Awnless and L1, Linkang 1 and Ningchun 4, had stronger root system, and showed better resistance to PEG than other wheat varieties. These materials might contain some genes controlling root traits or drought tolerance, and these characteristics might be derived from Th.intermedium. In addition, mature seeds of some materials and the calli derived from immature interspecies hybrid embryos were irradiated with γ-rays. Through field selection and laboratory identification, some new lines were developed from the offspring. Mutant TC2001-16 with a larger root system proved to be tolerant to drought stress, mutant TC2001-31 was resistant to stripe rust. (author)

  12. Molecular Mapping of a Stripe Rust Resistance Gene YrH9020a Transferred from Psathyrostachys huashanica Keng on Wheat Chromosome 6D

    Institute of Scientific and Technical Information of China (English)

    LIU Ze-guang; YAO Wei-yuan; SHEN Xue-xue; CHAO Kai-xiang; FAN Yu; LI Min-zhou; WANG Bao-tong; LI Qiang; JING Jin-xue

    2014-01-01

    Stripe rust (yellow rust), caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat throughout the world. H9020-1-6-8-3 is a translocation line originally developed from interspeciifc hybridization between wheat line 7182 and Psathyrostachys huashanica Keng and is resistant to most Pst races in China. To identify the resistance gene(s) in the translocation line, H9020-1-6-8-3 was crossed with susceptible cultivar Mingxian 169, and seedlings of the parents, F1, F2, F3, and BC1 generations were tested with prevalent Chinese Pst race CYR32 under controlled greenhouse conditions. The results indicated that there is a single dominant gene, temporarily designated as YrH9020a, conferring resistance to CYR32. The resistance gene was mapped by the F2 population from Mingxian 169/H9020-1-6-8-3. It was linked to six microsatellite markers, including Xbarc196, Xbarc202, Xbarc96, Xgpw4372, Xbarc21, and Xgdm141, lfanked by Xbarc96 and Xbarc202 with at 4.5 and 8.3 cM, respectively. Based on the chromosomal locations of these markers and the test of Chinese Spring (CS) nullitetrasomic and ditelosomic lines, the gene was assigned to chromosome 6D. According to the origin and the chromosomal location, YrH9020a might be a new resistance gene to stripe rust. The lfanking markers linked to YrH9020a could be useful for marker-assisted selection in breeding programs.

  13. Distribution, Frequency and Variation of Stripe Rust Resistance Loci Yr10, Lr34/Yr18 and Yr36 in Chinese Wheat Cultivars

    Institute of Scientific and Technical Information of China (English)

    Cuiling Yuan; Hui Jiang; Honggang Wang; Kun Li; Heng Tang; Xianbin Li; Daolin Fu

    2012-01-01

    Wheat stripe rust is a devastating disease in many regions of the world.In wheat,49 resistance genes for stripe rust have been officially documented,but only three genes are cloned,including the race-specific resistance Yr10 candidate gene (Yr10CG) and slow-rusting genes Lr34/Yr18 (hereafter designated as Yr18) and Yr36.In this study,we developed gene-specific markers for these genes and used them to screen a collection of 659 wheat accessions,including 485 Chinese cultivars.Thirteen percent and eleven percent of the tested Chinese cultivars were positive for the markers for Yr10CG and Yr18RH (the resistant haplotype of Yr18),respectively,but none were positive for the Yr36 marker.Since there is a limited use of the Yr10 gene in Chinese wheat,the relatively high frequency of wheat varieties with the Yr10CG marker suggests that the identity of the Yr10 gene is unknown.With regards to the Yr18 gene,29% of the tested cultivars that are used in the Middle and Lower Yangtze Valleys' winter wheat zone were positive for Yr18RH markers.A non-functional allele of Yr18RHwas identified in ‘Mingxian 169',a commonly used susceptible check for studying stripe rust.The data presented here will provide useful information for marker-assisted selection for wheat stripe rust resistance.

  14. Identification and Molecular Mapping of a Stripe Rust Resistance Gene from a Common Wheat Line Qzl80

    Institute of Scientific and Technical Information of China (English)

    DENGZhi-Yong; ZHANGXiang-Qi; WANGXian-Ping; JINGJian-Kang; WANGDao-Wen

    2004-01-01

    YrQz, a stripe rust disease resistance gene was identified in a common wheat (Triticumaestivum L.) line Qz180. This resistance was controlled by a single dominant gene, which was confirmed bygenetic analysis of two 1:2 populations derived from the crosses using Qz180 and two susceptible parents(Mingxian 169 and WL1). Bulked segregant analysis using simple sequence repeat (SSR) and amplifiedfragment length polymorphism (AFLP) markers was conducted in order to map the chromosomal locationof YrQz. The results indicated that YrQzwas located on the long arm of wheat chromosome 2B and residedin a re,on flanked by two SSR loci Xgwm388and Xgwm526. Two AFLP markers P35M48(452) and P36M61(163) were closely linked to KrQz with the genetic distance of 3.4 cM and 4.1 cM, respectively. To ourknowledge, this is the first molecularly mapped stripe rust resistance gene on wheat chromosome 2B.

  15. Molecular Characterization of a New Wheat-Thinopyrum intermedium Translocation Line with Resistance to Powdery Mildew and Stripe Rust

    Directory of Open Access Journals (Sweden)

    Haixian Zhan

    2015-01-01

    Full Text Available A new wheat-Thinopyrum translocation line CH13-21 was selected from the progenies derived from a cross between wheat-Th. intermedium partial amphiploid TAI7047 and wheat line Mianyang11. CH13-21 was characterized by using genomic in situ hybridization (GISH, multicolor-GISH (mc-GISH, multicolor-fluorescence in situ hybridization (mc-FISH and chromosome-specific molecular markers. When inoculated with stripe rust and powdery mildew isolates, CH13-21 displayed novel resistance to powdery mildew and stripe rust which inherited from its Thinopyrum parent. The chromosomal counting analyses indicated that CH13-21 has 42 chromosomes, with normal bivalent pairing at metaphase I of meiosis. GISH probed by Th. intermedium genomic DNA showed that CH13-21 contained a pair of wheat-Th. intermedium translocated chromosomes. Sequential mc-FISH analyses probed by pSc119.2 and pAs1 clearly revealed that chromosome arm 6BS of CH13-21 was replaced by Thinopyrum chromatin in the translocation chromosome. The molecular markers analysis further confirmed that the introduced Th. intermedium chromatin in CH13-21 belonged to the long arm of homoeologous group 6 chromosome. Therefore, CH13-21 was a new T6BS.6Ai#1L compensating Robertsonian translocation line. It concludes that CH13-21 is a new genetic resource for wheat breeding programs providing novel variation for disease resistances.

  16. TaTypA, a Ribosome-Binding GTPase Protein, Positively Regulates Wheat Resistance to the Stripe Rust Fungus.

    Science.gov (United States)

    Liu, Peng; Myo, Thwin; Ma, Wei; Lan, Dingyun; Qi, Tuo; Guo, Jia; Song, Ping; Guo, Jun; Kang, Zhensheng

    2016-01-01

    Tyrosine phosphorylation protein A (TypA/BipA) belongs to the ribosome-binding GTPase superfamily. In many bacterial species, TypA acts as a global stress and virulence regulator and also mediates resistance to the antimicrobial peptide bactericidal permeability-increasing protein. However, the function of TypA in plants under biotic stresses is not known. In this study, we isolated and functionally characterized a stress-responsive TypA gene (TaTypA) from wheat, with three copies located on chromosomes 6A, 6B, and 6D, respectively. Transient expression assays indicated chloroplast localization of TaTypA. The transcript levels of TaTypA were up-regulated in response to treatment with methyl viologen, which induces reactive oxygen species (ROS) in chloroplasts through photoreaction, cold stress, and infection by an avirulent strain of the stripe rust pathogen. Knock down of the expression of TaTypA through virus-induced gene silencing decreased the resistance of wheat to stripe rust accompanied by weakened ROS accumulation and hypersensitive response, an increase in TaCAT and TaSOD expression, and an increase in pathogen hyphal growth and branching. Our findings suggest that TaTypA contributes to resistance in an ROS-dependent manner.

  17. Wheat TaRab7 GTPase is part of the signaling pathway in responses to stripe rust and abiotic stimuli.

    Directory of Open Access Journals (Sweden)

    Furong Liu

    Full Text Available Small GTP-binding proteins function as regulators of specific intercellular fundamental biological processes. In this study, a small GTP-binding protein Rab7 gene, designated as TaRab7, was identified and characterized from a cDNA library of wheat leaves infected with Puccinia striiformis f. sp. tritici (Pst the wheat stripe rust pathogen. The gene was predicted to encode a protein of 206 amino acids, with a molecular mass of 23.13 KDa and an isoeletric point (pI of 5.13. Further analysis revealed the presence of a conserved signature that is characteristic of Rab7, and phylogenetic analysis demonstrated that TaRab7 has the highest similarity to a small GTP binding protein gene (BdRab7-like from Brachypodium distachyon. Quantitative real-time PCR assays revealed that the expression of TaRab7 was higher in the early stage of the incompatible interactions between wheat and Pst than in the compatible interaction, and the transcription level of TaRab7 was also highly induced by environmental stress stimuli. Furthermore, knocking down TaRab7 expression by virus induced gene silencing enhanced the susceptibility of wheat cv. Suwon 11 to an avirulent race CYR23. These results imply that TaRab7 plays an important role in the early stage of wheat-stripe rust fungus interaction and in stress tolerance.

  18. A new early-warning system for stripe rust affecting wheat and triticale: Host-pathogen interactions under different environmental conditions

    DEFF Research Database (Denmark)

    Rodriguez Algaba, Julian; Justesen, Annemarie Fejer; Hovmøller, Mogens Støvring

    Stripe (yellow) rust has been the most damaging disease in Danish organic wheat and triticale production since 2009. There were estimated losses of approximately 50 million DKK (9 million USD) in 2009. Until that time, triticale was considered the most robust cereal crop for organic farming...

  19. Monodehydroascorbate reductase gene, regulated by the wheat PN-2013 miRNA, contributes to adult wheat plant resistance to stripe rust through ROS metabolism.

    Science.gov (United States)

    Feng, Hao; Wang, Xiaojie; Zhang, Qiong; Fu, Yanping; Feng, Chuanxin; Wang, Bing; Huang, Lili; Kang, Zhensheng

    2014-01-01

    Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive wheat diseases worldwide. Varieties with adult plant resistance (APR) maintain effective and durable disease resistance. APR to stripe rust in wheat cultivar XZ9104 (XZ) is associated with extensive hypersensitive cell death and production of reactive oxygen species in the host. MDHAR is an important gene in the AsA-GSH cycle, and it plays an important role in maintaining the reduced pool of AsA scavenging hydrogen peroxide. microRNAs (miRNAs) were shown to engage in post-transcriptional regulation by degrading target mRNAs or repressing gene translation in plants responding to abiotic/biotic stresses. Previously, two novel miRNAs (1136-P3 and PN-2013) were isolated in wheat and the target gene of them was determined using degradome sequencing technology. In this study, the target gene was isolated and characterized as TaMDHAR, a monodehydroascorbate reductase gene. We first demonstrated that the target gene could be cleaved by these two miRNAs in tobacco leaves experimentally. However, TaMDHAR was regulated by PN-2013, not 1136-P3, in wheat-Pst adult incompatible interaction according to the expression patterns. The TaMDHAR knockdown resulted in improved wheat resistance to Pst at the seedling stage, with no influence on 1136-P3 and PN-2013 expression. The TaMDHAR knockdown resulted in a much greater H2O2 accumulation and lower APX and CAT activities together with higher expression in several PR genes. We deduced that TaMDHAR could contribute to the APR of XZ through ROS metabolism as regulated by the AsA-GSH cycle.

  20. Genome-Wide Linkage Mapping of QTL for Adult-Plant Resistance to Stripe Rust in a Chinese Wheat Population Linmai 2 × Zhong 892.

    Science.gov (United States)

    Liu, Jindong; He, Zhonghu; Wu, Ling; Bai, Bin; Wen, Weie; Xie, Chaojie; Xia, Xianchun

    2015-01-01

    Stripe rust is one of the most devastating diseases of wheat (Triticum aestivum) worldwide. Adult-plant resistance (APR) is an efficient approach to provide long-term protection of wheat from the disease. The Chinese winter wheat cultivar Zhong 892 has a moderate level of APR to stripe rust in the field. To determine the inheritance of the APR resistance in this cultivar, 273 F6 recombinant inbred lines (RILs) were developed from a cross between Linmai 2 and Zhong 892. The RILs were evaluated for maximum disease severity (MDS) in two sites during the 2011-2012, 2012-2013 and 2013-2014 cropping seasons, providing data for five environments. Illumina 90k SNP (single nucleotide polymorphism) chips were used to genotype the RILs and their parents. Composite interval mapping (CIM) detected eight QTL, namely QYr.caas-2AL, QYr.caas-2BL.3, QYr.caas-3AS, QYr.caas-3BS, QYr.caas-5DL, QYr.caas-6AL, QYr.caas-7AL and QYr.caas-7DS.1, respectively. All except QYr.caas-2BL.3 resistance alleles were contributed by Zhong 892. QYr.caas-3AS and QYr.caas-3BS conferred stable resistance to stripe rust in all environments, explaining 6.2-17.4% and 5.0-11.5% of the phenotypic variances, respectively. The genome scan of SNP sequences tightly linked to QTL for APR against annotated proteins in wheat and related cereals genomes identified two candidate genes (autophagy-related gene and disease resistance gene RGA1), significantly associated with stripe rust resistance. These QTL and their closely linked SNP markers, in combination with kompetitive allele specific PCR (KASP) technology, are potentially useful for improving stripe rust resistances in wheat breeding.

  1. TaLHY, a 1R-MYB Transcription Factor, Plays an Important Role in Disease Resistance against Stripe Rust Fungus and Ear Heading in Wheat.

    Science.gov (United States)

    Zhang, Zijin; Chen, Jieming; Su, Yongying; Liu, Hanmei; Chen, Yanger; Luo, Peigao; Du, Xiaogang; Wang, Dan; Zhang, Huaiyu

    2015-01-01

    LHY (late elongated hypocotyl) is an important gene that regulates and controls biological rhythms in plants. Additionally, LHY is highly expressed in the SSH (suppression subtractive hybridization) cDNA library-induced stripe rust pathogen (CYR32) in our previous research. To identify the function of the LHY gene in disease resistance against stripe rust, we used RACE-PCR technology to clone TaLHY in the wheat variety Chuannong19. The cDNA of TaLHY is 3085 bp long with an open reading frame of 1947 bp. TaLHY is speculated to encode a 70.3 kDa protein of 648 amino acids , which has one typical plant MYB-DNA binding domain; additionally, phylogenetic tree shows that TaLHY has the highest homology with LHY of Brachypodium distachyon(BdLHY-like). Quantitative fluorescence PCR indicates that TaLHY has higher expression in the leaf, ear and stem of wheat but lower expression in the root. Infestation of CYR32 can result in up-regulated expression of TaLHY, peaking at 72 h. Using VIGS (virus-induced gene silencing) technology to disease-resistant wheat in the fourth leaf stage, plants with silenced TaLHY cannot complete their heading stage. Through the compatible interaction with the stripe rust physiological race CYR32, Chuannong 19 loses its immune capability toward the stripe rust pathogen, indicating that TaLHY may regulate and participate in the heading of wheat, as well as the defense responses against stripe rust infection.

  2. Progress and Perspective in Research of Adult-Plant Resistance to Stripe Rust and Powdery Mildew in Wheat%小麦条锈病和白粉病成株抗性研究进展与展望

    Institute of Scientific and Technical Information of China (English)

    何中虎; 兰彩霞; 陈新民; 邹裕春; 庄巧生; 夏先春

    2011-01-01

    利用成株抗性是小麦抗病育种的重要方向,本文综述了小麦条锈病和白粉病成株抗性鉴定方法、基因定位和克隆及其在育种中的应用.将报道的72个条锈病成株抗性数量性状遗传位点(quantitative trait loci,QTL)和82个白粉病成株抗性QTL整合到一张连锁图谱上,控制2种病害的基因簇(≥5个QTL)有8个,其中位于7DS的Yr18/Lr34/Pm38和1BS的Yr29/Lr46/Pm39对条锈病、叶锈病和白粉病均表现成株抗性,位于4DL的Yr46/Lr67位点可能也对白粉病表现成株抗性,Yr18/Lr34/Pm38和Yr36已被克隆,Yr29/Lr46/Pm39的克隆已取得良好进展,为培育兼抗和成株抗性相结合的品种提供了可用基因.总结了成株抗性在中国小麦育种中的应用现状,并用实例证实了培育成株抗性品种的可行性,建议对兼抗条锈病和白粉病成株抗性的成农4号和小偃6号等进行遗传分析,育种工作者和品种审定部门需要转变观念,将成株抗性利用作为国内条锈病和白粉病抗性育种的重要内容.%Stripe rust, caused by Puccinia striiformis f.sp.tritici, and powdery mildew, caused by Blumeria graminis f.sp.tritici, are the devastating diseases in common wheat (Triticum aestivum L.) worldwide.Use of adult-plant resistance (APR) genes is an important method for the development of durable resistant cultivars.A total of 72 quantitative trait loci (QTLs) for APR to stripe rust and 82 QTLs for APR to powdery mildew were integrated into a linkage map based on the information of DNA markers linked to individual QTL.Eight gene clusters (≥5 QTLs) conferred resistance to both stripe rust and powdery powdery, among them,Yr18/Lr34/Pm38, Yr29/Lr46/Pm39, and Yr46/Lr67 showed resistance to stripe rust, leaf rust and powdery mildew.Yr18/Lr34/Pm38 and Yr36 have been cloned.Xiannong 4 and Xiaoyan 6 were very important resistant germplasm for APR to stripe rust and powdery midew.The application of APR to wheat breeding in China was

  3. The stripe rust resistance gene Yr10 encodes an evolutionary-conserved and unique CC-NBS-LRR sequence in wheat.

    Science.gov (United States)

    Liu, Wei; Frick, Michele; Huel, Réné; Nykiforuk, Cory L; Wang, Xiaomin; Gaudet, Denis A; Eudes, François; Conner, Robert L; Kuzyk, Alan; Chen, Qin; Kang, Zhensheng; Laroche, André

    2014-12-01

    The first seedling or all-stage resistance (R) R gene against stripe rust isolated from Moro wheat (Triticum aestivum L.) using a map-based cloning approach was identified as Yr10. Clone 4B of this gene encodes a highly evolutionary-conserved and unique CC-NBS-LRR sequence. Clone 4E, a homolog of Yr10, but lacking transcription start site (TSS) and putative TATA-box and CAAT-box, is likely a non-expressed pseudogene. Clones 4B and 4E are 84% identical and divergent in the intron and the LRR domain. Gene silencing and transgenesis were used in conjunction with inoculation with differentially avirulent and virulent stripe rust strains to demonstrate Yr10 functionality. The Yr10 CC-NBS-LRR sequence is unique among known CC-NBS-LRR R genes in wheat but highly conserved homologs (E = 0.0) were identified in Aegilops tauschii and other monocots including Hordeum vulgare and Brachypodium distachyon. Related sequences were also identified in genomic databases of maize, rice, and in sorghum. This is the first report of a CC-NBS-LRR resistance gene in plants with limited homologies in its native host, but with numerous homologous R genes in related monocots that are either host or non-hosts for stripe rust. These results represent a unique example of gene evolution and dispersion across species.

  4. 86份贵协系小麦种质资源对条锈病的抗病性评价%Identification of resistance to stripe rust in 86 Guixie wheat germplasm

    Institute of Scientific and Technical Information of China (English)

    王万军; 张庆勤; 曹世勤; 王晓明; 张立异; 黄瑾; 孙振宇; 张勃; 贾秋珍; 金社林

    2016-01-01

    小麦条锈病是发生于甘肃陇南麦区小麦生产上的最主要病害,利用和种植抗病品种(系)是防治该病害最经济有效且有利于保护环境的措施。2011-2013年度连续两年在甘肃省农业科学院植物保护研究所甘谷试验站田间对86份来自贵州大学的贵协系小麦种质资源材料进行了成株期抗条锈病鉴定,结果发现仅有‘贵协1’、‘贵协2’、‘贵协3’、‘贵协7’、‘贵协011-2-6’、‘贵协011-3-16’、‘贵协011-3-29’、‘贵协011-3-31’、‘贵协011-3-34’等9份材料表现抗病,且抗病性相对稳定,可作为一线抗源材料在陇南抗病育种中充分利用。%Wheat stripe rust,caused by biotrophic fungi Puccinia striiformis Westend.f.sp.tritici Erikss.&Henn.,is the most important wheat disease in Longnan region,Gansu Province,China.Eighty-six Guixie wheat germplasms originated from Guizhou University,were identified their resistance to stripe rust in fields at Gangu Testing Station,Institute of Plant Protection,Gansu Academy of Agricultural Sciences (IPP-GAAS)during 2011-2013.The results showed that 9 wheat germplasms including ‘Guixie 1’,‘Guixie 2’,‘Guixie 3’,‘Guixie 7’,‘Guixie 011-2-6’,‘Guixie 011-3-16’,‘Guixie 011-3-29’,‘Guixie 011-3-31’and ‘Guixie 011-3-34’,were resistant to stripe rust in field,and their resistance were relative stable.These 9 wheat germplasms could be recommended as valuable resistance resources for stripe rust in wheat breeding in Longnan region,Gansu Province in the future.

  5. QTL mapping of adult-plant resistance genes to stripe rust and leaf rust in CIMMYT wheat PBW343 and Muu%CIMMYT小麦PBW343和Muu中条锈和叶锈成株抗性QTL分析

    Institute of Scientific and Technical Information of China (English)

    邢丽芳; 李在峰; 刘大群

    2012-01-01

    In order to find the APR (adult-plant resistance) to leaf rust and stripe rust in CIMMYT wheat cultivars PBW343 and Muu, a total of 31 SSR, 16 EST, and 502 DArT markers were used to map QTLs for the resistance to wheat rusts in a recombinant inbred line (RIL population with 146 F6 families derived from the cross PBW343/Muu, using composite interval mapping strategy, two QTLs for APR to stripe rust and one for APR to leaf rust were detected on chromosomes 2AL, 2BL, and 5BL, explaining 8. 89% , 10. 81% and 12. 82% of the pheno-typic variance, respectively. The three QTLs all come from Muu, two QTLs for APR to stripe rust and one for APR to leaf rust will give theory and technology assistant to wheat resistance breeding.%为发掘CIMMYT小麦品种PBW343和Muu中条锈和叶锈成株抗性基因,以PBW343与Muu杂交的146个F6代重组自交系为材料,种植于田间调查鉴定,并利用31个SSR标记、16个EST标记和502个DArT( Diversity Arrays Technology)标记构建连锁图,采用复合区间作图法进行小麦条锈病和叶锈病的成株抗性QTL分析,发现了2个控制小麦抗条锈病和1个控制小麦抗叶锈病的QTL,分别位于2AL、2BL和5BL上,解释8.89%,10.81%和12.82%的表型变异,3个QTL均来自小麦品种Muu.这2个小麦抗条锈QTL和1个抗叶锈QTL的发掘,将为小麦抗病育种提供理论和技术支持.

  6. First Report of Soybean Rust Caused by Phakopsora pachyrhizi in Ghana

    Science.gov (United States)

    Nigeria is the only country in West Africa where soybean rust, caused by Phakopsora pachyrhizi has been officially reported (1). During a disease survey in Ghana in October 2006, soybean (Glycine max) leaves with rust symptoms (tan, angular lesions with erumpent sori exuding urediniospores) were ob...

  7. Control of Wheat Stripe Rust and Ensuring High Yield of Crops under Planting of Wheat Variety Mixtures%小麦多品种混播对条锈病的控制及稳产作用研究

    Institute of Scientific and Technical Information of China (English)

    沈丽; 叶香萍; 廖华明; 何华健; 王胜; 刘如东; 罗林明

    2008-01-01

    Wheat stripe rust has become the facet dangerous disease which threaten safe yield d wheat in Sichuan Province.IT is meaningful to provide technique support for integrated disease control by exploring the effective control measures of wheat stripe rest.Wheat stripe rust dynamic developments of all-planting and mixed-planting have been systematically investigated in this study by taking different mixed-planting combinations among 6 wheat varieties with different resistance levels.The results of this experiment show that the mixed-plantings of 4 and 6 wheat varieties can delay the ocenrance of wheat stripe rust,slow the speed of disease and decline the damage of disease as well as stabilize yield of wheats.

  8. Molecular mapping of stripe rust resistance gene YrSE5756 in synthetic hexaploid wheat and its transfer to common wheat

    International Nuclear Information System (INIS)

    Synthetic hexaploid wheat is an important germplasm resource for transfer of beneficial genes from alien species to common wheat (Triticum aestivum L.). Synthetic hexaploid wheat SE5756 confers a high level of resistance against a wide range of races of Puccinia striiformis West. f. sp. tritici Eriks. et Henn.(Pst). The objectives of this study were to determine the inheritance pattern, adjacent molecular markers, and chromosomal location of the stripe rust resistance gene in SE5756 and to develop new germplasm. We constructed a segregating population of 116 F2 plants and corresponding F2:3 families from a cross between SE5756 and Xinong979 with Pst races CYR32. Genetic analysis revealed that a single dominant gene, tentatively designated as YrSE5756, was responsible for seedling stage stripe rust resistance in SE5756. A genetic map, encompassing Xwmc626, Xwmc269, Xgwm11, Xbarx137, Xwmc419, Xwmc85, Xgpw5237, Xwmc134, WE173, Xwmc631, and YrSE5756, spanned 70.1 cM on chromosome 1BS. Xwmc419 and Xwmc85 were flanking markers tightly linked to YrSE5756 at genetic distances of 2.3 and 1.8 cM. Typical adult plant responses of the SE5756, varieties of the carrier Yr10 and Yr15, Chuanmai 42 (Yr24/Yr26), Yuanfeng 175 (Yr24/Yr26) and Huixianhong resistant to mixture Pst races (CYR32, CYR33 and V26) were experimented. The results showed that YrSE5756 was likely a new resistance stripe rust gene different from Yr24/Yr26, Yr10 and Yr15. From cross and backcross populations of SE5756/Xinong 979, we developed four new wheat lines with large seeds, stripe rust resistance, and improved agronomic traits: N07178-1, N07178-2, N08256-1, and N08256-2. These new germplasm lines could serve as sources of resistance to stripe rust in wheat breeding. SE5756 has the very vital significance in the development of breeding and expand our resistance germplasm resource gene pool. (author)

  9. Construction and characterization of a full-length cDNA library for the wheat stripe rust pathogen (Puccinia striiformis f. sp. tritici

    Directory of Open Access Journals (Sweden)

    Chen Xianming

    2007-06-01

    Full Text Available Abstract Background Puccinia striiformis is a plant pathogenic fungus causing stripe rust, one of the most important diseases on cereal crops and grasses worldwide. However, little is know about its genome and genes involved in the biology and pathogenicity of the pathogen. We initiated the functional genomic research of the fungus by constructing a full-length cDNA and determined functions of the first group of genes by sequence comparison of cDNA clones to genes reported in other fungi. Results A full-length cDNA library, consisting of 42,240 clones with an average cDNA insert of 1.9 kb, was constructed using urediniospores of race PST-78 of P. striiformis f. sp. tritici. From 196 sequenced cDNA clones, we determined functions of 73 clones (37.2%. In addition, 36 clones (18.4% had significant homology to hypothetical proteins, 37 clones (18.9% had some homology to genes in other fungi, and the remaining 50 clones (25.5% did not produce any hits. From the 73 clones with functions, we identified 51 different genes encoding protein products that are involved in amino acid metabolism, cell defense, cell cycle, cell signaling, cell structure and growth, energy cycle, lipid and nucleotide metabolism, protein modification, ribosomal protein complex, sugar metabolism, transcription factor, transport metabolism, and virulence/infection. Conclusion The full-length cDNA library is useful in identifying functional genes of P. striiformis.

  10. Wheat Stripe Rust Resistance Protein WKS1 Reduces the Ability of the Thylakoid-Associated Ascorbate Peroxidase to Detoxify Reactive Oxygen Species.

    Science.gov (United States)

    Gou, Jin-Ying; Li, Kun; Wu, Kati; Wang, Xiaodong; Lin, Huiqiong; Cantu, Dario; Uauy, Cristobal; Dobon-Alonso, Albor; Midorikawa, Takamufi; Inoue, Kentaro; Sánchez, Juan; Fu, Daolin; Blechl, Ann; Wallington, Emma; Fahima, Tzion; Meeta, Madhu; Epstein, Lynn; Dubcovsky, Jorge

    2015-06-01

    Stripe rust is a devastating fungal disease of wheat caused by Puccinia striiformis f. sp tritici (Pst). The WHEAT KINASE START1 (WKS1) resistance gene has an unusual combination of serine/threonine kinase and START lipid binding domains and confers partial resistance to Pst. Here, we show that wheat (Triticum aestivum) plants transformed with the complete WKS1 (variant WKS1.1) are resistant to Pst, whereas those transformed with an alternative splice variant with a truncated START domain (WKS1.2) are susceptible. WKS1.1 and WKS1.2 preferentially bind to the same lipids (phosphatidic acid and phosphatidylinositol phosphates) but differ in their protein-protein interactions. WKS1.1 is targeted to the chloroplast where it phosphorylates the thylakoid-associated ascorbate peroxidase (tAPX) and reduces its ability to detoxify peroxides. Increased expression of WKS1.1 in transgenic wheat accelerates leaf senescence in the absence of Pst. Based on these results, we propose that the phosphorylation of tAPX by WKS1.1 reduces the ability of the cells to detoxify reactive oxygen species and contributes to cell death. This response takes several days longer than typical hypersensitive cell death responses, thus allowing the limited pathogen growth and restricted sporulation that is characteristic of the WKS1 partial resistance response to Pst.

  11. The expression and genetics of resistance to stripe (yellow) rust in three European and four New Zealand wheat cultivars.

    Science.gov (United States)

    Pathan, Amin K; Park, Robert F; Wellings, Colin R; Bariana, Harbans S

    2007-01-01

    Adult plant resistance (APR) to stripe rust in three European (Pegaso, Victo and Aztec) and four New Zealand cultivars (Weka, Kopara, Kokart and Takahe) was characterised using hybrid analysis and tests of allelism. In agreement with earlier work, the APR in most of these cultivars appeared to be controlled by two or more genes with additive effects. It was suggested that heavy selection pressure should be avoided in early generations in breeding programs utilising APR, because lines in which APR genes are heterozygous may display lower levels of resistance due to the incompletely dominant and interactive nature of many APRs. Such lines are capable of generating more resistant progenies following selfing. It was also demonstrated that it is possible to misclassify F2 plants as susceptible if APR genes are in a heterozygous condition, especially in the case of gene(s) conferring intermediate levels of resistance. The presence of a common APR gene in Kopara and Takahe, and perhaps Weka, was suggested because all shared a common parent in their pedigree and no susceptible plants were observed in F2 populations derived from intercrossing them. The difficulties inherent in conducting genetic studies on APRs and the need for large population sizes for such studies were emphasised. PMID:17666772

  12. Identification of an AFLP marker linked to the stripe rust resistance gene Yr1O in wheat

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    AFLP analysis of near-isogenic lines of the stripe rust resistance gene Yr10 was carried out with 6 Pst Ⅰprimers and 10 Taq Ⅰ -primers with the donor parent of Yr10 gene as the check. A total of about 4200 distinguishable bands were amplified, of which 5 were stable. The genetic linkage of the 5 polymorphic DNA fragments with the target gene were tested preliminarily on a segregating F2 population derived from a cross between the gene donor parent "Moro" and susceptible cultivar "Mingxian 169". The DNA fragment PT0502 was found closely linked to the Yr10 gene and cloned and sequenced. Based on the sequence specific primers for PCR were designed and synthesized. Genetic linkage analysis with 195 segregating F2 plants indicated that the genetic distance was 05 cM between the main product SC200 fragment produced by PCR with the primers and the Yr10 gene. The primers can be used to detect the Yr10 gene quickly, effectively and exactly.``

  13. Red stripe caused by Acidovirax avenae subsp. avenae in Louisiana sugarcane

    Science.gov (United States)

    Red stripe of sugarcane caused by Acidovirax avenae subsp. avenae is considered to be of minor importance because, most often when found, only the mild leaf stripe symptom is observed. In 2010, both leaf stripe and the more severe top rot symptom were observed in commercial sugarcane fields in Louis...

  14. Identification and mapping stripe rust resistance gene YrLM168a using extreme individuals and recessive phenotype class in a complicate genetic background.

    Science.gov (United States)

    Feng, Junyan; Chen, Guoyue; Wei, Yuming; Liu, Yaxi; Jiang, Qiantao; Li, Wei; Pu, Zhien; Lan, Xiujin; Dai, Shoufen; Zhang, Min; Zheng, Youliang

    2015-12-01

    The identification and characterization of resistance genes effective against stripe rust of wheat is beneficial for modern wheat breeding programs. Molecular markers to such genes facilitate their deployment. The variety Milan has resistance that is effective against the predominant stripe rust races in the Sichuan region. Two resistant and two susceptible F8 lines from a cross between Milan and the susceptible variety Chuannong 16 were used to investigate inheritance of the Milan resistance. Three F2 populations were developed from crosses between the resistant lines and their susceptible sibling lines (LM168a × LM168c, LM168c × LM168a, LM168b × LM168d) and used for genetic analysis and molecular mapping of the genes for resistance. The stripe rust resistance in LM168a and LM168b was conferred by a single dominant gene, temporarily designated as YrLM168a. Forty-five extreme susceptible plants from the F2 families of LM168d × LM168b were genotyped with 836 simple sequence repeat (SSR) markers to map YrLM168a. YrLM168a was mapped in chromosome 6BL. The nearest flanking markers Xwmc756 and Xbarc146 were 4.6 and 4.6 cM away from the gene at both sides, respectively. The amplification results of twenty extreme resistant (IT 0) and susceptible (IT 4) F2 plants of LM168c × LM168a and LM168a × LM168c with marker Xwmc756 further validated the mapping results. The study suggested that extreme individuals and recessive phenotype class can be successfully used for mapping genes, which should be efficient and reliable. In addition, the flanking markers near YrLM168a should be helpful in marker-assisted breeding.

  15. Characterization of Stripe Rust Resistance Genes in the Wheat Cultivar Chuanmai45

    Directory of Open Access Journals (Sweden)

    Ennian Yang

    2016-04-01

    Full Text Available The objective of this research was to characterize the high level of resistance to stripe that has been observed in the released wheat cultivar, Chuanmai45. A combination of classic genetic analysis, molecular and cytogenetic methods were used to characterize resistance in an F2 population derived from Chuanmai45 and the susceptible Chuanmai42. Inheritance of resistance was shown to be conferred by two genes in Chuanmai45. Fluorescence in situ hybridization (FISH was used along with segregation studies to show that one gene was located on a 1RS.1BL translocation. Molecular markers were employed to show that the other locus was located on chromosome 4B. The defeated gene, Yr24/26, on chromosome 1BL was present in the susceptible parent and lines that recombined this gene with the 1RS.1BL translocation were identified. The germplasm, loci, and associated markers identified in this study will be useful for application in breeding programs utilizing marker-assisted selection.

  16. Genome-Wide Analysis of Simple Sequence Repeats and Efficient Development of Polymorphic SSR Markers Based on Whole Genome Re-Sequencing of Multiple Isolates of the Wheat Stripe Rust Fungus.

    Directory of Open Access Journals (Sweden)

    Huaiyong Luo

    Full Text Available The biotrophic parasitic fungus Puccinia striiformis f. sp. tritici (Pst causes stripe rust, a devastating disease of wheat, endangering global food security. Because the Pst population is highly dynamic, it is difficult to develop wheat cultivars with durable and highly effective resistance. Simple sequence repeats (SSRs are widely used as molecular markers in genetic studies to determine population structure in many organisms. However, only a small number of SSR markers have been developed for Pst. In this study, a total of 4,792 SSR loci were identified using the whole genome sequences of six isolates from different regions of the world, with a marker density of one SSR per 22.95 kb. The majority of the SSRs were di- and tri-nucleotide repeats. A database containing 1,113 SSR markers were established. Through in silico comparison, the previously reported SSR markers were found mainly in exons, whereas the SSR markers in the database were mostly in intergenic regions. Furthermore, 105 polymorphic SSR markers were confirmed in silico by their identical positions and nucleotide variations with INDELs identified among the six isolates. When 104 in silico polymorphic SSR markers were used to genotype 21 Pst isolates, 84 produced the target bands, and 82 of them were polymorphic and revealed the genetic relationships among the isolates. The results show that whole genome re-sequencing of multiple isolates provides an ideal resource for developing SSR markers, and the newly developed SSR markers are useful for genetic and population studies of the wheat stripe rust fungus.

  17. Resistance in Salix against willow leaf rust caused by Melampsora epitea

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Leif [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Crop Production Science

    2000-07-01

    Cultivation of Salix in short rotation forests (SRF), as a source of renewable energy is a relatively recent phenomenon in Sweden. As all other crops under intensive cultivation, Salix are attacked by pests. The economically most important disease is leaf rust caused by Melampsora epitea. For successful plant breeding of new sustainable rust resistant clones, it is important to have knowledge of the inheritance of resistance and the mechanisms underlying rust resistance. Species hybridisation is one technique used in plant breeding, hence the inheritance pattern of rust resistance in hybrids of two species, S. viminalis and S. dasyclados, selected for the purpose, was studied in greenhouse as well as under field conditions. The study in greenhouse showed that hybrids acquire intermediate rust resistance compared to pure species. Plants of same hybrids in field proved to be more resistant than their parental species. Observations in field also showed that abiotic factors such as weather tend to play a significant role in expression of inheritance pattern. It was further indicated that the interaction between rust and Salix might be race-specific. Metabolic changes in Salix, induced by the pathogen in incompatible and compatible interactions were studied in terms of peroxidase and chitinase activity which were measured in S. viminalis inoculated with rust of two different pathotypes of M. epitea rust. Peroxidase activity revealed an earlier response from plants in the incompatible interactions compared to compatible interactions. Records of the chitinase accumulation showed absence of one basic isoform of chitinase in the incompatible interaction. These results demonstrated physiological differences between incompatible and compatible interactions, and gave further indication toward occurrence of race-specific interactions in this pathosystem. Further, with use of molecular biology techniques, a gene designated svpk1, was cloned and partially characterised. The gene

  18. Wheat zinc finger protein TaLSD1, a negative regulator of programmed cell death, is involved in wheat resistance against stripe rust fungus.

    Science.gov (United States)

    Guo, Jun; Bai, Pengfei; Yang, Qian; Liu, Furong; Wang, Xiaodong; Huang, Lili; Kang, Zhensheng

    2013-10-01

    Genetic characterization of the Arabidopsis lesion simulating disease 1 (lsd1) mutant, a lesion mimic mutant (LMM), has revealed the essential role of AtLSD1 in the negative regulation of cell death and disease resistance. The three zinc-finger motifs found in AtLSD1 revealed a novel plant-specific gene family, whose members are significantly related to programmed cell death (PCD). In this study, we characterized a functional homologue to AtLSD1, TaLSD1, in the wheat-stripe rust fungus pathosystem. The expression of TaLSD1 was differentially induced during incompatible and compatible interactions between wheat and Puccinia striiformis f. sp. tritici (Pst) and was up-regulated by oxidative stress generated by methyl viologen (MV). TaLSD1 was found to be predominately localized in the nucleus of onion epidermal cell. Transient overexpression assays in Nicotiana benthamiana demonstrated that TaLSD1 partially inhibited programmed cell death triggered by a mouse Bax protein, whereas expression of TaLSD1 alone had no influence on the phenotype of tobacco. Knocking down the expression of TaLSD1 through virus-induced gene silencing (VIGS) increased wheat resistance against Pst accompanied by an enhanced hypersensitive response (HR), an increase in PR1 gene expression and a reduction in Pst hyphal growth. Our results suggest that TaLSD1 functions negatively in regulating the plant hypersensitive cell death and is involved in disease resistance of wheat against the stripe rust pathogen.

  19. First report of Phakopsora pachyrhizi causing rust on soybean in Malawi

    Science.gov (United States)

    Soybean rust (SBR), caused by Phakopsora pachyrhizi, has rapidly become established in Africa since the first report in Uganda in 1996. The urediniospores, as windborne propagules, have infested new regions of Africa, initiating SBR in many countries, including Ghana and Democratic Republic of the C...

  20. Stripe rust resistance and dough quality of new wheat - Dasypyrum villosum translocation lines T1DL•1V#3S and T1DS•1V#3L and the location of HMW-GS genes.

    Science.gov (United States)

    Zhao, W C; Gao, X; Dong, J; Zhao, Z J; Chen, Q G; Chen, L G; Shi, Y G; Li, X Y

    2015-01-01

    The transfer of agronomically useful genes from wild wheat species into cultivated wheat is one of the most effective approaches to improvement of wheat varieties. To evaluate the transfer of genes from Dasypyrum villosum into Triticum aestivum, wheat quality and disease resistance was evaluated in two new translocation lines, T1DL•1V#3S and T1DS•1V#3L. We examined the levels of stripe rust resistance and dough quality in the two lines, and identified and located the stripe rust resistant genes and high molecular weight glutenin subunit (HMW-GS) genes Glu-V1 of D. villosum. Compared to the Chinese Spring (CS) variety, T1DL•1V#3S plants showed moderate resistance to moderate susceptibility to the stripe rust races CYR33 and Su11-4. However, T1DS•1V#3L plants showed high resistance or immunity to these stripe rusts. The genes for resistance to stripe rust were located on 1VL of D. villosum. In comparison to CS, the dough from T1DS•1V#3L had a significantly shorter developing time (1.45 min) and stable time (1.0 min), a higher weakness in gluten strength (208.5 FU), and a lower farinograph quality index (18). T1DL•1V#3S had a significantly longer developing time (4.2 min) and stable time (5.25 min), a lower weakness in gluten strength (53 FU) and a higher farinograph quality index (78.5). We also found that T1DS•1V#3L had reduced gluten strength and dough quality compared to CS, but T1DL•1V#3S had increased gluten strength and dough quality. The results of SDS-PAGE analysis indicated that Glu-V1 of D. villosum was located on short arm 1VS and long arm 1VL. These results prove that the new translocation lines, T1DS•1V#3L and T1DS•1V#3L, have valuable stripe rust resistance and dough quality traits that will be important for improving wheat quality and resistance in future wheat breeding programs.

  1. Genetic diversity analysis of varieties resistant to stripe rust based on SSR markers%小麦抗条锈品种遗传多样性的SSR分析

    Institute of Scientific and Technical Information of China (English)

    刘文涛; 程登发; 康晓慧; 孙京瑞; 张云慧; 罗宵凤; 张梅; 张利; 张娜

    2011-01-01

    [Objective] Genetic diversity of wheat varieties resistant to stripe rust in the main wheat production areas in China were analyzed by SSR markers to provide a reference for selection of parental materials resistant to wheat stripe rust. [Method] Several dominant wheat cultivars were assessed for resistance to stripe rust at adult stage by using the current races of the stripe rust. Genetic diversity was investigated by SSR markers. [Result] Totally 104 alleles were produced by 27 pairs of SSR primers. The average alleles per pair of primers were 3.85. The polymorphism information content (PIC) ranged from 0.210 to 0.712 with an average value of 0.455. Wheat cultivars resistant to stripe rust had a genetic similarity coefficient of 0.723 on average, which indicated that the genetic diversity of the resistant varieties was low. [Conclusion] Cluster analysis results showed that wheat cultivars resistant to stripe rust were divided into 4 groups,and genetic distance was related to geographical distance to some extent.%[目的]利用SSR标记分析我国几大小麦产区主栽品种中抗锈品种的遗传多样性,为小麦抗条锈育种亲本材料的选择提供参考.[方法]以当前条锈菌优势小种接种成株期小麦,从几大小麦产区主栽品种中筛选出抗条锈品种.然后利用SSR标记对筛选出的抗锈品种的遗传多样性进行分析.[结果]27对SSR引物在上述抗锈品种中共检测到104个等位变异,平均为3.85个;引物的多态信息含量(PIC)在0.210~0.712之间,平均为0.455;抗锈品种间遗传相似系数平均为0.723,表明筛选出的抗锈品种遗传多样性较低,亲缘较近.[结论]聚类分析的结果将抗锈品种分为了4个类群,类群的分布与亲缘的远近和品种的地域有一定的相关性.

  2. Wheat Production and Wheat Rust Management in Canada

    Institute of Scientific and Technical Information of China (English)

    Xue Allen G; Chi Dawn T; Zhang Shu-zhen; Li Zuo-fu

    2012-01-01

    Wheat is Canada's the largest crop with most of the production in the western Canadian Prairie Provinces of Manitoba, Saskatchewan and Alberta. There were approximately 10 million (M) hectares (hm2) seeded to wheat in Canada, including 7 M hm2 of hexaploid spring wheat (Triticum aestivum L.), 2 M hm2 of durum wheat (T. turgidum L. ssp. durum (Desf.) Husn.), and 1 M hm2 of winter wheat (T. aestivum). Within hexaploid wheat there has been diversification into a number of market classes based on different end-use quality criteria. The predominant spring bread wheat class has been the Canada Western Red Spring (CWRS) class. Historically, the disease of major concern in wheat was stem rust, caused by Puccinia graminis f. sp. tritici. The first significant stem rust resistant cultivar in Canada was Thatcher, grown extensively from 1939 until the early 1970s. Thatcher, however, was very susceptible to leaf rust, caused by Puccinia triticina. Over years, improved resistance to both stem and leaf rust was achieved with the release of cultivars with additional genes for resistance, primarily Sr2, Sr6, Sr7a, Sr9b, Lr13, Lr14a, Lr16, and Lr34. The genetic resistance has adequately controlled stem rust but leaf rust continues to cause significant loss, partially due to changes in the P. triticina population which reduced the effectiveness of resistance genes such as Lr13 and Lr16. Stripe rust on wheat, caused by Puccinia striiformis f. sp. tritici, was historically a problem under irrigation in southern Alberta, but since 2000, it has been found annually in the central Canadian prairies and southern Ontario. The genetic basis of resistance to stripe rust in most Canadian wheat cultivars has not been determined, although Yr18 provides partial resistance in many cultivars. In the future, other rust diseases, such as wheat stripe rust, or highly virulent new pathotypes of current rust pathogens, such as P. graminis f. sp. tritici race Ug-99, may pose

  3. Variation and Selection Effects of Resistance to Stripe Rust in the Progenies of Wheat Space Mutagenesis%小麦航天诱变后代的条锈病抗性变异及选择效果研究

    Institute of Scientific and Technical Information of China (English)

    杜久元; 白斌; 金明安; 何春雨; 包文生; 张廷刚; 周祥椿

    2012-01-01

    为明确小麦航天诱变后代条锈病抗性的变异和选择效果,在甘肃陇南用系谱法对8个小麦品种的诱变后代进行了研究。结果表明,兰天10号、兰天14号、兰天17号在SP1(诱变一代)和SP2(诱变二代),PASCAL和85-173-4在SP2的群体病谱均较原品种对照发生了不显著的变异,但它们在SP1和SP2都没有出现显著的条锈病抗性突变体;郑麦9023、陇原031和DORICO在SP2均出现了显著的条锈病抗性突变系且有分离现象。8个品种的SP2和SP3(诱变三代)共获得9个显著的条锈病抗性突变系和12个显著的非条锈病抗性突变系,其中15个突变系的后代都出现了条锈病抗性的分离和变异。经过4代的选择,证明感病品种在SP2出现的抗性不显著提高株系具有一定的选择可靠性,从郑麦9023和陇原031中分别获得了抗条锈、大粒和兼抗条锈、白粉病的优良突变系。这些结果表明,航天诱变小麦种子能够引起后代条锈病抗性的丰富变异;变异可能出现在SP1、SP2或以后世代;对于感病品种在SP2出现的抗性不显著提高株系可以进行选择;不论哪一方面性状的显著突变系,一般会随世代进展出现条锈病抗性的分离和变异,都应作为抗性选择的目标对象而注意保留。%To elucidate the characteristics of variation and selection effects on resistance to stripe rust in the progenies of wheat cultivars by space mutation, the variation of stripe rust resistance in proge- nies of eight space mutant eultivars were analyzed by pedigree selection method in Longnan of Gansu province. Few mutant plants with significant variation of resistance {or stripe rust had been detected in generation SP1 and SP2 of cultivars Lantian 10, Lantian 14 and Lantianl7, and in SP2 of 85-173-4 and PASCAL. In susceptible cultivars Zhengmai 9023, Longyuan 031 and DOR1CO, both mutant plants with high resistant and with severe susceptible to stripe rust were found

  4. Genetic Analysis and Molecular Mapping of an All-Stage Stripe Rust Resistance Gene inTriticum aestivum-Haynaldia villosa Translocation Line V3

    Institute of Scientific and Technical Information of China (English)

    HOU Lu; MA Dong-fang; HU Mao-lin; HE Miao-miao; LU Yan; JING Jin-xue

    2013-01-01

    chromosomal location, the reaction patterns and pedigree analysis,YrV3should be a novel gene for resistance to stripe rust in wheat. These closely linked markers should be useful in stacking genes from different sources for wheat breeding and diversiifcation of resistance genes against stripe rust.

  5. TaEIL1, a wheat homologue of AtEIN3, acts as a negative regulator in the wheat-stripe rust fungus interaction.

    Science.gov (United States)

    Duan, Xiaoyuan; Wang, Xiaojie; Fu, Yanping; Tang, Chunlei; Li, Xiaorui; Cheng, Yulin; Feng, Hao; Huang, Lili; Kang, Zhensheng

    2013-09-01

    Transcription factors (TFs) play crucial roles in the transcriptional regulation of plant development and defence responses. Increasing evidence has implicated ETHYLENE INSENSITIVE3 (EIN3) in the plant defence response to pathogen infection and environmental stimuli. However, the role of EIN3 in wheat resistance to Puccinia striiformis f. sp. tritici (Pst) is not clear. Here, TaEIL1 was isolated by rapid amplification of cDNA ends (RACE) based on a sequence fragment from a wheat-Pst interaction cDNA library. The TaEIL1 protein contains a typical EIN3-binding domain, and transient expression analyses indicated that TaEIL1 is localized in the nucleus. Yeast one-hybrid assay revealed that TaEIL1 exhibits transcriptional activity, and its C-terminus is necessary for the activation of transcription. TaEIL1 transcripts were regulated by environmental stress stimuli and were decreased under salicylic acid (SA) treatment. When wheat leaves were challenged with Pst, the transcript level of TaEIL1 in the compatible interaction was approximately three times higher than that in the incompatible interaction. Knocking down TaEIL1 through the Barley stripe mosaic virus (BSMV) virus-induced gene silencing (VIGS) system attenuated the growth of Pst, with shortened hyphae and reduced hyphal branches, haustorial mother cells and colony size. Moreover, enhanced necrosis was triggered by the Pst avirulent race CYR23, indicating that the hypersensitive response was strengthened in TaEIL1-silenced wheat plants. Thus, the up-regulation of defence-related genes and increased sucrose abundance might contribute to the enhanced disease resistance of wheat to the virulent race CYR31. Taken together, the results suggested that the suppression of TaEIL1 transcripts could enhance the resistance of wheat to stripe rust fungus.

  6. Aster albescens Rust Caused by Aecidium asterum and Its Hyperparasitic Fungus Tuberculina persicina

    Institute of Scientific and Technical Information of China (English)

    HUANG Yun; YE Hua-zhi; CHEN Guang-yan; LIU Zi-ying; DONG Bao-chen

    2005-01-01

    Aster albescens is a medicinal plant. The rust caused by Aecidium asterum is a new record in China and an important disease of A. albescens in Feng Tong-zhai national reservation area. The percentages of diseased plant and the diseased leaf reach 100 and 28% respectively when the disease is serious. The disease results in leaf spot and leaf cast. Tuberculina persicina is a natural hyperparasite of A. asterum and is firstly reported in the world. The hyperparasite attacks aecium of A. asterum and hinderes the release of aeciospores. The symptom of the rust and the morphological characteristics of A.asterum is reported. The hyperparasitism of A. asterum and the morphological characteristics of the Tuberculina persicina are also reported.

  7. Study on Comprehensive Prevention and Control Technology of Wheat Stripe Rust in Nanchong City%南充市小麦条锈病综合防控技术研究

    Institute of Scientific and Technical Information of China (English)

    彭昌家; 李鸿韬; 何海燕; 肖立; 崔德敏; 丁攀; 冯礼斌; 白体坤; 陈如胜; 尹怀中; 龙维国; 文旭; 王婉秋

    2015-01-01

    为了控制条锈病为害,减少农药污染、防治成本和菌源传出数量,确保本地、邻近麦区与中国东部主产麦区生产安全和可持续发展。通过采用田间系统监测和普查、小麦品种抗性鉴定、条锈菌生理小种监测、试验示范和气象资料分析等方法,开展了小麦条锈病综合防控技术研究。结果表明,各主栽小麦品种的抗锈性随着种植年限的增加而降低,并逐步淘汰。3~5年更换一次具有不同抗源的主推品种,实现品种合理布局和多抗源品种集团当家,能有效降低条锈病发生为害。首次探明了小麦间作不同作物防治小麦条锈病的效果为14.84%~62.89%,推行药剂拌种、健身栽培,可推迟并减轻条锈病发生为害,降低越冬菌源量和春季流行程度;探明了条锈病最佳防治方案为拔节期、孕穗期和抽穗扬花期各施药1次;探明了几种新药剂防治条锈病效果和25%丙环唑防治条锈病的适宜用量(600~650 mL/hm2)。首次提出了本市小麦条锈病综合治理策略。搞好防治示范片和应急防控,可以显著提高防治效果,并带动大面积防控落实。1999年以来,全市小麦条锈病偏重至大发生频率虽高达81.25%,但通过应用综合防控技术措施,小麦产量实际损失率均控制在2%以下(特大发生的2002年除外),同时减少农药使用量1591 t。%In order to control the epidemic of stripe rust, reduce the cost and pollution of pesticide, suppress the spread amount of inoculum source, and ensure safe production and sustainable development in wheat producing areas, comprehensive prevention technology research of wheat stripe rust was performed in Nanchong, Sichuan Province. Through systemic monitoring and census in the field, wheat resistance identification, stripe rust physiological race inspection, comprehensive treatment and meteorological data analysis, the results were obtained and

  8. DIVERSITY OF PUCCINIA KUEHNII AND P. MELANOCEPHALA CAUSING RUST DISEASES ON BRAZILIAN SUGARCANE

    Science.gov (United States)

    Sugarcane industry in Brazil suffers yield loss due to brown rust (Puccinia melanocephala) since 1986 and orange rust (P. kuehnii) as recent as 2009. The main control measure for both diseases has been cultivar resistance. Nevertheless, recent onsets of orange rust on previously resistant cultivars ...

  9. TaRAR1 and TaSGT1 associate with TaHsp90 to function in bread wheat (Triticum aestivum L.) seedling growth and stripe rust resistance.

    Science.gov (United States)

    Wang, Guan-Feng; Fan, Renchun; Wang, Xianping; Wang, Daowen; Zhang, Xiangqi

    2015-04-01

    RAR1 and SGT1 are important co-chaperones of Hsp90. We previously showed that TaHsp90.1 is required for wheat seedling growth, and that TaHsp90.2 and TaHsp90.3 are essential for resistance (R) gene mediated resistance to stripe rust fungus. Here, we report the characterization of TaRAR1 and TaSGT1 genes in bread wheat. TaRAR1 and TaSGT1 each had three homoeologs, which were located on wheat groups 2 and 3 chromosomes, respectively. Strong inhibition of seedling growth was observed after silencing TaSGT1 but not TaRAR1. In contrast, decreasing the expression of TaRAR1 or TaSGT1 could all compromise R gene mediated resistance to stripe rust fungus infection. Protein-protein interactions were found among TaRAR1, TaSGT1 and TaHsp90. The N-terminus of TaHsp90, the CHORD-I and CHORD-II domains of TaRAR1 and the CS domain of TaSGT1 may be instrumental for the interactions among the three proteins. Based on this work and our previous study on TaHsp90, we speculate that the TaSGT1-TaHsp90.1 interaction is important for maintaining bread wheat seedling growth. The TaRAR1-TaSGT1-TaHsp90.2 and TaRAR1-TaSGT1-TaHsp90.3 interactions are involved in controlling the resistance to stripe rust disease. The new information obtained here should aid further functional investigations of TaRAR1-TaSGT1-TaHsp90 complexes in regulating bread wheat growth and disease resistance.

  10. 云南咖啡抗锈品种抗锈性丧失原因及防治对策%Cause and Preventive Countermeasures for Breakdown of Resistance to Rust in Rust Resistance Coffee Cultivars in Yunnan

    Institute of Scientific and Technical Information of China (English)

    张洪波; 白学慧; 李锦红; 李文伟; 周华; 胡永亮

    2011-01-01

    According to the occurrence of rust disease in rust resistance coffee cultivars in different growing areas in Yunnan and combined with distribution of races of rust disease in China, investigations and studies on cause for breakdown of resistance to rust in fields are carried out. Results show that interactions between host, pathogen and environment make physiological races of rust resistance coffee cultivars mutation constantly and disability. Study on persistent selection of rust resistance coffee cultivars as well as the importance of rational allocation on persistent of rust resistance of coffee cultivars are described. Measurements to control rust disease are put forward.%针对云南咖啡抗锈品种不同植区出现锈病,结合国内锈病小种分布情况,开展了咖啡大田抗锈性丧失原因的调查研究,结果表明:寄主一病原菌一环境的相互作用,使咖啡锈病生理小种不断变异,导致抗锈性丧失,阐述了持久抗锈品种选育研究和合理配置对咖啡品种抗锈持久的重要性,提出了防治锈病的措施。

  11. 临麦系列春小麦品种抗条锈性分析%Resistance analysis on spring wheat cultivar of Linmai lines to stripe rust in Linxia,Gansu Province

    Institute of Scientific and Technical Information of China (English)

    李永平; 曹世勤; 金社林; 冯晶; 谭璀榕

    2016-01-01

    Wheat stripe rust (yellow rust),caused by Puccinia striiformis f.sp.tritici (Pst ),is one of the most destructive disease in wheat in Linxia,Gansu Province of China.Growing resistant cultivars is the most economi-cal,environmental friendly,and effective method to control stripe rust of wheat.Five planting spring wheat culti-vars,including ‘Linmai 32’,‘Linmai 33’,‘Linmai 34’,‘Linmai 35’and ‘Linmai 36’,which were important wheat varieties in Linxia region since 2000,were selected to evaluate their resistance to stripe rust at all-stage time by artificially inoculating differential races of Pst in Lanzhou greenhouse of Institute of Plant Protection,Gansu Academy of Agricultural Sciences (IPP-GAAS)at seedling stage,and Gangu Testing Station of IPP-GAAS at adult stage in 2013,and natural induced pool at 8 different location in Gansu Province during 2010-2014.The results showed that the wheat varieties ‘Linmai 32’were susceptible to the tested isolates of Pst at seedling stage,middle resistant-susceptible to CYR29 and CYR32,and susceptible to other isolates of Pst at adult stage.The wheat vari-ety ‘Linmai 33’was immune to CYR29 at seedling stage,middle resistant-susceptible at adult stage,and suscepti-ble to other tested isolates of Pst at all stage,and susceptible to natural isolates at 8 different locations in Gansu Province,China.The wheat varieties ‘Linmai 34’and ‘Linmai 36’were susceptible to G22-9,G22-14,and re-sistant to other isolates.They were also susceptible in field since 2013.The wheat variety ‘Linmai 35’was resist-ant to the testing and natural isolates of Pst in all-stage.Artificial inoculation of 24 single isolates of Pst with dif-ferent spectra of pathogenicity was carried out at seedling stage in Beijing greenhouse (Institute of Plant Protec-tion,Chinese Academy of Agricultural Sciences,IPP-CAAS).The results showed that the resistant spectra of the tested Linmai spring varieties were different from that of the

  12. Resistance Potential of Bread Wheat Genotypes Against Yellow Rust Disease Under Egyptian Climate.

    Science.gov (United States)

    Mahmoud, Amer F; Hassan, Mohamed I; Amein, Karam A

    2015-12-01

    Yellow rust (stripe rust), caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F8 recombinant inbred lines (RILs) derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI) was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant) and Sakha-69 (susceptible) were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 2 yellow rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.

  13. Outbreak of Rust Caused by Coleosporium asterum on Solidago virgaurea var. gigantea in Ulleung-do

    OpenAIRE

    Back, Chang-Gi; Nam, Gu-Youn; Lee, Seung-Yeol; Jung, Hee-Young

    2014-01-01

    From June to October 2012, severe outbreaks of rust disease on Solidago virgaurea var. gigantea were observed in 5 different regions of Ulleung-do, Korea. Typical rust symptoms appeared as yellow spots, uredinia on leaves, and massive urediniospores covering the entire plant. Severely infected plants became discolored and died. On the basis of its morphological and molecular characteristics, the causal agent was identified as Coleosporium asterum. This pathogen has been reported as rust disea...

  14. Agro-climatic Risk Zoning of Wheat Stripe Rust in Spring of Sichuan Province%四川省小麦条锈病春季流行的农业气候风险区划

    Institute of Scientific and Technical Information of China (English)

    游超; 肖天贵; 李金建; 张菡

    2012-01-01

    From the perspective of risk zoning, there was little research on the relationship between wheat stripe rust and meteorological condition method during the past years. Based on the theory of agrometeorological disaster risk, this paper developed the agricultural climate risk model to study wheat stripe rust of Sichuan Province in spring with the help of correlation analysis, AHP and range normalization methods. Coinstantaneously, the model included two environmental factors such as climate condition and the number of host plants. Then the risk index was divided into high, medium and low-grades clearly by using the model. After all, with GIS technology, the spring risk zoning of wheat stripe rust in Sichuan Province was carried out. Finally, t he result showed that, the western Sichuan Plateau, as well as the mountainous area of southwest Sichuan and the southwest basin region belonged to the low risk area. Meanwhile, the high and medium area included the the most of Sichuan basin where the wheat stripe rust happened frequently in spring. This paper supplied theoretical basis for the forecast in subarea and integrated control of wheat stripe rust in Sichuan Province. Based on the conclusion which showed that the risk assessment coincided with the actual situation generally, better services for decision-making to disease pests prevention and reduction could be provided.%针对当前从气象风险角度开展小麦条锈病与气象关系研究甚少的状况,从农业气象灾害风险分析理论出发,采用相关分析、层次分析和极差正规化等方法,建立了包含气候条件和寄主存在数量两个环境因子的四川省小麦条锈病春季流行农业气候风险模型,并划分了高、中、低风险等级的指标.在此基础上,利用GIS技术对四川省小麦条锈病春季流行的农业气候风险进行了区划.结果表明,四川省的川西高原地区、川西南山地和盆地西南部是小麦条锈病春季流行低风险区,

  15. Development and Molecular Cytogenetic Identification of a Novel Wheat-Leymus mollis Lm#7Ns (7D Disomic Substitution Line with Stripe Rust Resistance.

    Directory of Open Access Journals (Sweden)

    Xiaofei Yang

    Full Text Available Leymus mollis (2n = 4x = 28, NsNsXmXm possesses novel and important genes for resistance against multi-fungal diseases. The development of new wheat-L. mollis introgression lines is of great significance for wheat disease resistance breeding. M11003-3-1-15-8, a novel disomic substitution line of common wheat cv. 7182 -L. mollis, developed and selected from the BC1F5 progeny between wheat cv. 7182 and octoploid Tritileymus M47 (2n = 8x = 56, AABBDDNsNs, was characterized by morphological and cytogenetic identification, analysis of functional molecular markers, genomic in situ hybridization (GISH, sequential fluorescence in situ hybridization (FISH-genomic in situ hybridization (GISH and disease resistance evaluation. Cytological observations suggested that M11003-3-1-15-8 contained 42 chromosomes and formed 21 bivalents at meiotic metaphase I. The GISH investigations showed that line contained 40 wheat chromosomes and a pair of L. mollis chromosomes. EST-STS multiple loci markers and PLUG (PCR-based Landmark Unique Gene markers confirmed that the introduced L. mollis chromosomes belonged to homoeologous group 7, it was designated as Lm#7Ns. While nulli-tetrasomic and sequential FISH-GISH analysis using the oligonucleotide Oligo-pSc119.2 and Oligo-pTa535 as probes revealed that the wheat 7D chromosomes were absent in M11003-3-1-15-8. Therefore, it was deduced that M11003-3-1-15-8 was a wheat-L. mollis Lm#7Ns (7D disomic substitution line. Field disease resistance demonstrated that the introduced L. mollis chromosomes Lm#7Ns were responsible for the stripe rust resistance at the adult stage. Moreover, M11003-3-1-15-8 had a superior numbers of florets. The novel disomic substitution line M11003-3-1-15-8, could be exploited as an important genetic material in wheat resistance breeding programs and genetic resources.

  16. A new rust disease on wild coffee (Psychotria nervosa) caused by Puccinia mysuruensis sp. nov

    Science.gov (United States)

    Psychotria nervosa, commonly called wild coffee (Rubiaceae) is an important ethno-medicinal plant in India. In 2010 a new rust disease of P. nervosa was observed in three regions of Mysore District, Karnataka (India) with disease incidence ranging from 58% to 63%. Typical symptoms of rust disease we...

  17. Outbreak of Rust Caused by Coleosporium asterum on Solidago virgaurea var. gigantea in Ulleung-do.

    Science.gov (United States)

    Back, Chang-Gi; Nam, Gu-Youn; Lee, Seung-Yeol; Jung, Hee-Young

    2014-03-01

    From June to October 2012, severe outbreaks of rust disease on Solidago virgaurea var. gigantea were observed in 5 different regions of Ulleung-do, Korea. Typical rust symptoms appeared as yellow spots, uredinia on leaves, and massive urediniospores covering the entire plant. Severely infected plants became discolored and died. On the basis of its morphological and molecular characteristics, the causal agent was identified as Coleosporium asterum. This pathogen has been reported as rust disease on S. virgaurea in the Canada and United States. In Korea, rust disease on S. virgaurea var. gigantea was reported as Uromyces rudbeckia in 1992. To the best of our knowledge, C. asterum is a novel rust pathogen on S. virgaurea var. gigantea in Korea.

  18. Development of structural response diagram approach to evaluation of thermal stress caused by thermal striping

    Energy Technology Data Exchange (ETDEWEB)

    Kasahara, Naoto; Yacumpai, Apisara [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Takasho, Hideki

    1999-02-01

    At incomplete mixing area of high temperature and low temperature fluids near the surface of structures, temperature fluctuation of fluid gives thermal fatigue damage to wall structures. This thermohydraulic and thermomechanical coupled phenomenon is called thermal striping, which has so complex mechanism and sometimes causes crack initiation on the structural surfaces that rational evaluation methods are required for screening rules in design codes. In this study, frequency response characteristics of structures and its mechanism were investigated by both numerical and theoretical methods. Based on above investigation, a structural response diagram was derived, which can predict stress amplitude of structures from temperature amplitude and frequency of fluids. Furthermore, this diagram was generalized to be the Non-dimensional structural response diagram by introducing non-dimensional parameters such as Biot number, non-dimensional frequency, and non-dimensional stress. The use of the Non-dimensional structural response diagram appears to evaluate thermal stress caused by thermal striping, rapidly without structural analysis, and rationally with considering attenuation by non-stationary heat transfer and thermal unloading. This diagram can also give such useful information as sensitive frequency range to adjust coupled thermohydraulic and thermomechanical analysis models taking account of four kinds of attenuation factors: turbulent mixing, molecular diffusion, non-stationary heat transfer, and thermal unloading. (author)

  19. Inheritances of Resistance to Powdery Mildew and Stripe Rust in Cryptic Alien Introgression from Thinopyrum intermedium%小偃麦渐渗系对白粉病和条锈病抗性的遗传分析

    Institute of Scientific and Technical Information of China (English)

    詹海仙; 李光蓉; 张晓军; 李欣; 畅志坚

    2012-01-01

    CH5382 is a stable cryptic alien introgression carrying resistance genes of Thinopyrum intermedium. It was highly resistant to both powdery mildew and stripe rust disease. To determine the resistance inheritances in it, CH5382 was crossed with three susceptible cultivars (line ). The adult tests of F1 , F2 and F3 progenies from these crosses and their parents were inoculated with Egt isolate E09 in Taiyuan greenhouse and with mixed Pst isolates including CYR32 at Sichuan disease nursery Respectively. It was consistent to both powdery mildew (IT0) and stripe rust (IT 0; ) for F, plants and their resistant parent CH5382 indicating complete dominance of the two resistances in these crosses. Powdery mildew resistant and susceptible segregation ratios satisfactorily fit 3R: 1S in the F2 populations and segregation ratios for stripe rust reaction of F2 progenies from these crosses suit 3R: 1S. The F2.3 lines displayed a segregation ratio of 1 (all R): 2 segregating: 1 (all S) ,demonstrating that the powdery mildew resistance and stripe rust resistance in CH5382 were conferred by a single dominant gene separately.%CH5382是一个携带中间偃麦草抗性基因的隐形异源渐渗系,它兼抗白粉病和条锈病.为明确其抗性的遗传规律,用高感品种绵阳11、台长29和SY95-71杂交,将其F1、F2、F3家系及其亲本分别在太原温室(用白粉病E09菌系接种)和四川成都电子科技大学农场(用条锈病菌CYR32接种)进行了抗性基因的遗传分析.结果表明,F1对2种病害的抗性分别为免疫(0级),近免疫(0;级);F2分离群体中,白粉病抗感分离比例符合3R:1S;条锈病的抗感分离比例也符合3R:1S;F3家系的抗感分离比例均符合1R:2Seg:1S的理论比例.说明小偃麦渐渗系CH5382对白粉病和条锈病的抗性均受1对显性基因控制.

  20. Target of tae-miR408, a chemocyanin-like protein gene (TaCLP1), plays positive roles in wheat response to high-salinity, heavy cupric stress and stripe rust.

    Science.gov (United States)

    Feng, Hao; Zhang, Qiong; Wang, Qiuling; Wang, Xiaojie; Liu, Jia; Li, Man; Huang, Lili; Kang, Zhensheng

    2013-11-01

    microRNAs (miRNAs) are novel and significant regulators of gene expression at the post-transcriptional level, and they are essential for normal growth and development and adaptation to stress conditions. As miRNAs are a kind of RNAs that do not code proteins, they play roles by repressing gene translation or degrading the corresponding target mRNAs. Plantacyanin-like (basic blue) proteins have been predicted and verified as the target gene of miR408 in wheat and Arabidopsis, respectively. Besides some biochemical characteristics, their detailed biological function remains unknown. In this study, the target gene of a wheat miRNA (tae-miR408), designated TaCLP1, was identified using degradome sequencing and co-transformation technology in tobacco leaves. We isolated the full-length cDNA clone, and defined its product as a chemocyanin-like protein, a kind of plantacyanin. Transcript accumulation of TaCLP1 and tae-miR408 showed contrasting divergent expression patterns in wheat response to Puccinia striiformis f. sp. tritici (Pst) and high copper ion stress. Overexpression of TaCLP1 in yeast (Schizosaccharomyces pombe) significantly increased cell growth under high salinity and Cu²⁺ stresses. Silencing of individual cDNA clones in wheat challenged with Pst indicated that TaCLP1 positively regulates resistance to stripe rust. The results indicate that the target of tae-miR408, TaCLP1, play an important role in regulating resistance of host plants to abiotic stresses and stripe rust, and such interactions can be a valuable resource for investigating stress tolerance in wheat.

  1. Evaluation and inheritance analysis of resistance to stripe rust in American wheat source IR35%美国小麦种质资源IR35抗条锈性评价及遗传分析

    Institute of Scientific and Technical Information of China (English)

    骆惠生; 曹世勤; 黄瑾; 贾秋珍; 张勃; 冯晶; 金社林

    2013-01-01

    2006-2011年对美国小麦种质资源材料‘IR35’进行了抗条锈病评价及遗传分析.结果发现,‘IR35’在苗期、成株期均表现中度抗病,苗期基因推导分析发现该品种含有未知抗条锈病基因;遗传分析表明‘IR35’对条锈菌条中32号的抗病性由1对显性基因控制,对条中33号的抗病性由1对隐性基因控制.‘IR35’可作为小麦抗条锈病资源材料进一步研究利用.%The wheat germplasm ' IR35', which comes from USA, was moderately resistant to stripe rust in all-stage in greenhouse and in field in Gansu Province. The genetic resistance character of ' IR35' was studied. Gene postulation showed that 'IR35' possessed unknown resistant genes or gene combination using differential isolates of Puccinia striiformis at seedling stage. The resistance to stripe rust race CYR32 was controlled by one dominant gene, and one recessive gene to CYR33. The wheat germplasm 'IR35' was worth using in wheat breeding in the future in Gansu Province.

  2. Critical-point model to estimate yield loss caused by Asian soybean rust

    Directory of Open Access Journals (Sweden)

    Anderson Luiz Durante Danelli

    2015-12-01

    Full Text Available ABSTRACTA model to estimate yield loss caused by Asian soybean rust (ASR (Phakopsora pachyrhizi was developed by collecting data from field experiments during the growing seasons 2009/10 and 2010/11, in Passo Fundo, RS. The disease intensity gradient, evaluated in the phenological stages R5.3, R5.4 and R5.5 based on leaflet incidence (LI and number of uredinium and lesions/cm2, was generated by applying azoxystrobin 60 g a.i/ha + cyproconazole 24 g a.i/ha + 0.5% of the adjuvant Nimbus. The first application occurred when LI = 25% and the remaining ones at 10, 15, 20 and 25-day intervals. Harvest occurred at physiological maturity and was followed by grain drying and cleaning. Regression analysis between the grain yield and the disease intensity assessment criteria generated 56 linear equations of the yield loss function. The greatest loss was observed in the earliest growth stage, and yield loss coefficients ranged from 3.41 to 9.02 kg/ha for each 1% LI for leaflet incidence, from 13.34 to 127.4 kg/ha/1 lesion/cm2 for lesion density and from 5.53 to 110.0 kg/ha/1 uredinium/cm2 for uredinium density.

  3. The genome sequence and effector complement of the flax rust pathogen Melampsora lini

    Directory of Open Access Journals (Sweden)

    Adnane eNemri

    2014-03-01

    Full Text Available Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp. Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimise parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analysed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote

  4. First report of Orange Rust of Sugarcane Caused by Puccinia kuehnii in Costa Rica and Nicaragua

    Science.gov (United States)

    Symptoms of orange rust of sugarcane were observed in Costa Rica at Coopeagri Sugar Mill located in Pérez Zeledón, San José, during July 2007 on (a complex hybrid of Saccharum L. species) cultivar, SP 71-5574, and at Providencia Sugar Mill near Muelle and at Cutris Sugar Mill near Los Chiles, in Aug...

  5. First Report of Garlic Rust Caused by Puccinia allii on Allium sativum in Minnesota

    Science.gov (United States)

    In July 2010, Allium sativum, cultivar German Extra Hardy Porcelain plants showing foliar symptoms typical of rust infection were brought to the Plant Disease Clinic at the University of Minnesota by a commercial grower from Fillmore county Minnesota. Infected leaves showed circular to oblong lesio...

  6. MOLECULAR SCREENING OF LEAF RUST AND STRIP RUST RESISTANCE GENES IN F5 BREAD WHEAT IN EGYPT

    OpenAIRE

    Reham M. Abd El-Azeem; S. H. M. Abd-El-Haleem

    2014-01-01

    Highly wheat production in Egypt is constrained due to many diseases. Rust and stripe (yellow) rust diseases consider from the most important wheat diseases in Egypt. Thus, molecular screening of genetically resistant cultivars, varieties, accessions and hybrids offspring through many generations, is one of the most sustainable solutions to overcome these diseases. The objective of this study is screening strip (yellow) rust and leaf rust resistance genes in the three parents ...

  7. Disease Index Inversion of Wheat Stripe Rust on Different Wheat Varieties with Hyperspectral Remote Sensing%基于高光谱遥感技术的不同小麦品种条锈病病情指数的反演

    Institute of Scientific and Technical Information of China (English)

    郭洁滨; 黄冲; 王海光; 孙振宇; 马占鸿

    2009-01-01

    应用混合品种控制小麦条锈病在国内外日益受到重视,通过采集田间不同品种混合小麦条锈病各级病情梯度的高光谱遥感数据,将光谱数据与条锈病病情数据进行相关性分析,利用4个光谱参数构建其与病情指数的同归模型.结果表明,不同小麦晶种组合在不同的病情指数情况下,其冠层光谱信息都表现了一致的变化规律;冠层反射率在可见光区与病情指数为正相关,而在近红外区则达到了显著的负相关;利用690与850 nm处的反射率、SDr、NDVI以及RVI与病情指数构建的回归模型拟合效果较好.研究表明利用高光谱反演条锈病病情指数是可行的,并且小麦不同品种对反演效果影响小大.%It is becoming more and more important to use mixed wheat varieties to control wheat stripe rust. Different wheat va-rieties were planted in field and stripe rust was caused by artificial inoculation. Disease index (DI) was assessed and the canopy reflection data of wheat canopy were obtained by ASD FieldSpec HandHeld FR(325-1 075 nm) made by ASD Company. The correlation analysis between DI and spectral data (reflectance and the first derivative) was conducted, and the estimation models between DI and reflection data (reflectance at 690 and 850 nm, SDr, NDVI and RVI) were built using linear regression method. The results showed that different combinations of wheat varieties had the similar variation at different disease index. DI has posi-tive correlation with reflectance of wheat canopy in visible region, and has significant negative correlation in the near infrared re-gion. DI has stable negative correlation with the first derivative in the region of 700-760 nm and with big fluctuation in other re-gions. The correlation was compared between DI and hyperspectral derivative index, and SDr has the best correlation with DI. DI estimation models were built based on the canopy reflectance at 690 and 850 nm, SDr, NDVI and RVI. The

  8. TaNAC1 acts as a negative regulator of stripe rust resistance in wheat, enhances susceptibility to Pseudomonas syringae, and promotes lateral root development in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Fengtao; Lin, Ruiming; Feng, Jing; Chen, Wanquan; Qiu, Dewen; Xu, Shichang

    2015-01-01

    Plant-specific NAC transcription factors (TFs) constitute a large family and play important roles in regulating plant developmental processes and responses to environmental stresses, but only some of them have been investigated for effects on disease reaction in cereal crops. Virus-induced gene silencing (VIGS) is an effective strategy for rapid functional analysis of genes in plant tissues. In this study, TaNAC1, encoding a new member of the NAC1 subgroup, was cloned from bread wheat and characterized. It is a TF localized in the cell nucleus, and contains an activation domain in its C-terminal. TaNAC1 was strongly expressed in wheat roots and was involved in responses to infection by the obligate pathogen Puccinia striiformis f. sp. tritici and defense-related hormone treatments such as salicylic acid (SA), methyl jasmonate, and ethylene. Knockdown of TaNAC1 with barley stripe mosaic virus-induced gene silencing (BSMV-VIGS) enhanced stripe rust resistance. TaNAC1-overexpression in Arabidopsis thaliana plants gave enhanced susceptibility, attenuated systemic-acquired resistance to Pseudomonas syringae DC3000, and promoted lateral root development. Jasmonic acid-signaling pathway genes PDF1.2 and ORA59 were constitutively expressed in transgenic plants. TaNAC1 overexpression suppressed the expression levels of resistance-related genes PR1 and PR2 involved in SA signaling and AtWRKY70, which functions as a connection node between the JA- and SA-signaling pathways. Collectively, TaNAC1 is a novel NAC member of the NAC1 subgroup, negatively regulates plant disease resistance, and may modulate plant JA- and SA-signaling defense cascades.

  9. TaNAC1 acts as a negative regulator of stripe rust resistance in wheat, enhances susceptibility to Pseudomonas syringae, and promotes lateral root development in transgenic Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Fengtao eWang

    2015-02-01

    Full Text Available Plant-specific NAC transcription factors constitute a large family and play important roles in regulating plant developmental processes and responses to environmental stresses, but only some of them have been investigated for effects on disease reaction in cereal crops. Virus-induced gene silencing (VIGS is an effective strategy for rapid functional analysis of genes in plant tissues. In this study, TaNAC1, encoding a new member of the NAC1 subgroup, was cloned from bread wheat and characterized. It is a transcription factor localized in the cell nucleus, and contains an activation domain in its C-terminal. TaNAC1 was strongly expressed in wheat roots and was involved in responses to infection by the obligate pathogen Puccinia striiformis f. sp. tritici and defense-related hormone treatments such as salicylic acid, methyl jasmonate and ethylene. Knockdown of TaNAC1 with barley stripe mosaic virus-induced gene silencing (BSMV-VIGS enhanced stripe rust resistance. TaNAC1-overexpression in Arabidopsis plants gave enhanced susceptibility, attenuated systemic-acquired resistance to Pseudomonas syringae DC3000, and promoted lateral root development. Jasmonic acid-signaling pathway genes PDF1.2 and ORA59 were constitutively expressed in transgenic plants. TaNAC1 overexpression suppressed the expression levels of resistance-related genes PR1 and PR2 involved in SA signaling and AtWRKY70, which functions as a connection node between the JA- and SA-signaling pathways. Collectively, TaNAC1 is a novel NAC member of the NAC1 subgroup, negatively regulates plant disease resistance, and may modulate plant JA- and SA-signaling defense cascades.

  10. Detection of Puccinia kuehnii Causing Sugarcane Orange Rust with a Loop-Mediated Isothermal Amplification-Based Assay.

    Science.gov (United States)

    Chandra, Amaresh; Keizerweerd, Amber T; Grisham, Michael P

    2016-03-01

    Puccinia kuehnii is a fungal pathogen that causes orange rust in sugarcane, which is now prevalent in many countries. At the early stage of disease, it is almost indistinguishable from brown rust, which is caused by Puccinia melanocephala. Although several PCR assays are available to detect these diseases, the loop-mediated isothermal amplification (LAMP)-based assay has been reported to be more economical and easier to perform. Under isothermal conditions, DNA is amplified with high specificity and rapidity. Moreover, visual judgment of color change without further post-amplification processing makes the method convenient. The present study was undertaken to detect P. kuehnii genomic DNA using four primers corresponding to a unique DNA sequence of P. kuehnii. The LAMP assay was found to be optimal when 8 mM MgSO4 was used and the reaction was incubated at 63 °C for 90 min. Positive samples showed a color change from orange to green upon SYBR Green I dye addition. Specificity of the LAMP test was checked with DNA of P. melanocephala, which showed no reaction. Sensitivity of the LAMP method was observed to be the same as real-time PCR at 0.1 ng, thus providing a rapid and more affordable option for early disease detection. PMID:26837389

  11. Molecular Cytogenetic Characterization of Secale Africanum Introgression Wheat Lines for Resistance to Stripe Rust%抗条锈小麦-非洲黑麦渐渗系的分子细胞学鉴定

    Institute of Scientific and Technical Information of China (English)

    贾举庆; 郭红媛; 李倩冉; 董娟; 杨武德; 杨足君

    2012-01-01

    Secale africanum shows short plant height, cross pollination and excellent resistance to wheat diseases. It is thus essential to study its potential value for wheat improvement. In this study, molecular cytogenetic methods were used to evaluate Secale africanum introgression wheat lines and materials for developing stripe rust resistance substitution and translocation lines were found, which offered good genetic stocks for further utilizing the S. africaum chro-matin in the wheat breeding by chromosome manipulation.%非洲黑麦(Secale a fricanum Stapf)具有矮杆、异花授粉、抗多种小麦病害等优异性状,在小麦可持续性抗病遗传育种中具有重要作用.利用分子细胞生物学的方法对小麦与非洲黑麦育成的渐渗系材料进行鉴定,发现了抗条锈病的新的代换系和易位系材料,为进一步在小麦染色体工程育种中开展非洲黑麦基因资源的利用提供很好的遗传材料.

  12. 小偃麦新种质CH7102抗条锈病特性的遗传分析%Inheritance of Stripe Rust Resistance in Thinopyrum ponticum-derived Wheat Introgression Line CH7102

    Institute of Scientific and Technical Information of China (English)

    刘洁; 畅志坚; 李欣; 张晓军; 詹海仙; 郭慧娟

    2013-01-01

    This study aimed at determining the response to Chinese stripe rust races, the origin and inheritance mode of resistance gene in a new Thinopyrum ponticum-derived wheat introgression line CH7102. Seedlings of Th. ponticum (accession R431), CH7102 and its resistant parent partial amphiploid 'Xiaoyan 7430' as well as all wheat parents were evaluated in the greenhouse using CYR31 and CYR32, the most widely virulent and predominant pathotypes in China. CH7102 was crossed respectively to susceptible cultivars 'Taichung 29' and ' Mianyang 11' and the lines containing known resistance genes, and the resulting segregating populations F2, F3 and BCi were used for genetic analysis of stripe rust response and allelism tests of resistance gene in CH7102. When inoculated with race CYR32 at the adult plant stage, F, plants from both crosses showed infection types (IT) similar to the resistant parent, indicating that resistance was dominant. The segregation ratios in the F2 and BCi populations and F3 lines were consistent with those expected for segregation at a single locus. When tested with the same race at the seedling stage, the segregation for resistant and susceptible showed a good fit with a 15:1 ratio in all F2 populations from crossing CH7102 with five lines containing known resistance genes. The stripe rust resistance in wheat-alien introgression line CH7102 was controlled by a single dominant gene, presumably having been transferred from T. ponticum. Based on the result from allelism tests, the resistance gene in CH7102 was different from the known effective resistance genes Yr5, YrlO, Yrl5 Yr24l Yr26 and Yr41, and is possibly a new gene for resistance to stripe rust.%对衍生于普通小麦与八倍体小偃麦‘小偃7430’杂种后代的抗条锈病新种质CH7102进行抗性鉴定和遗传分析,明确其抗性来源及其遗传方式.采用条锈菌流行小种CYR31、CYR32对CH7102及其亲本进行苗期抗性评价;对CH7102分别与感病品种和已知

  13. Glyphosate inhibits rust diseases in glyphosate-resistant wheat and soybean

    OpenAIRE

    Feng, Paul C. C.; Baley, G. James; Clinton, William P.; Bunkers, Greg J.; Alibhai, Murtaza F.; Paulitz, Timothy C.; Kidwell, Kimberlee K.

    2005-01-01

    Glyphosate is a broad-spectrum herbicide used for the control of weeds in glyphosate-resistant crops. Glyphosate inhibits 5-enolpyruvyl shikimate 3-phosphate synthase, a key enzyme in the synthesis of aromatic amino acids in plants, fungi, and bacteria. Studies with glyphosate-resistant wheat have shown that glyphosate provided both preventive and curative activities against Puccinia striiformis f. sp. tritici and Puccinia triticina, which cause stripe and leaf rusts, respectively, in wheat. ...

  14. 基于高光谱影像的小麦条锈病光谱信息探测与提取%Spectral Information Detection and Extraction of Wheat Stripe Rust Based on Hyperspectral Image

    Institute of Scientific and Technical Information of China (English)

    杨可明; 陈云浩; 郭达志; 蒋金豹

    2008-01-01

    为了理解与定量分析农作物光谱特征和相关参数,基于PHI高光谱影像建立了农作物病害光谱响应与探测模型,即光谱点位与参数模型(FPPM).为了识别和提取小麦条锈病信息,根据多时相高光谱影像光谱特征,提出了一种可调节的多时相归一化植被指数(MT-NDVI).结果表明,FPPM能很好地响应与感知该病害在小麦生长期的光谱特征;结合光谱角制图法(SAM),MT-NDVI能清楚地呈现不同区域该病害的轻重程度,准确地区分和提取小麦条锈病与健康小麦及土壤的信息.%In order to analyze and detect wheat stripe rust disease quantitatively, a Feature Position and Parameter Mode (FPPM) of spectral responses and disease detection is built based on the airborne wheat PHI(Pushbroom hyperspectral imager) images, and a new adjustable Multi-Temporal Normalized Difference Vegetation Index (MT-NDVI) is provided to extract the disease information in terms of the temporal spectral features. The results show that the FPPM can well response and monitor the disease occurring during the wheat growing, and the MT-NDVI method integrating Spectral Angle Mapper(SAM) technique can represent clearly the disease where is serious, slight or not influential, distinguish and extract the disease information accurately from health wheat and soil.

  15. 中草药苍耳、黄瑞香水浸液对小麦条锈病菌的抑制作用%Inhibition Effect of Extract of Daphne giraldii nitsche and Siberian Coeklebu:Fruit on Wheat Stripe Rust

    Institute of Scientific and Technical Information of China (English)

    叶文斌; 张和平; 樊亮

    2013-01-01

      小麦条锈病是小麦生产中的重要病害之一,为了明确中草药苍耳和黄瑞香提取液对小麦条锈病的抑制作用,分别以两种中药水浸液测定其对小麦条锈病菌的抑制作用,以及对小麦条锈病的防治效果.结果显示,不同浓度的苍耳、黄瑞香提取液对小麦条锈菌孢子萌发和菌丝生长均有抑制作用,在浓度为0.50 g/ mL条件下对其孢子的萌发抑制率分别为69.29%和64.44%,对其菌丝生长的抑制率分别为55.44%和44.77%.两种中药浸提液叶面喷施试验结果显示,两种中药浸提液对小麦条锈病都具有显著的防治效果.%Wheat stripe rust is one of the most damaging wheat plant diseases. In this study,different concentration gradients of Daphne giraldii nitsche and Siberian Coeklebu:Fruit extracts were used to control rust sporangium germination and mycelial growth. The results showed that two kinds of herbal medicine aqueous extract inhibited the growth of sporangium germination and mycelia of rust. With 0. 50 g/ mL concentration of Daphne giraldii nitsche and Siberian Coeklebu:Fruit,inhibiting rates of wheat stripe rust spore germination were 69. 29% and 64. 44%,and inhibiting rates of mycelial growth were 5. 44% and 44. 77%,respectively. In conclusion,the study demonstrated that spraying these two kinds of herbal medicine aqueous extracts had significant preventive effect on stripe rust fungi at both seedling and maturity stages.

  16. Over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici) in the California Central valley: A case study Supervivencia estival de la roya estriada (Puccinia striiformis f.sp. tritici) del trigo en el Valle Central de California: Estudio de caso

    OpenAIRE

    Huib Tollenaar

    2012-01-01

    To study the over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici) in the California Central Valley (CCV), temperature records from various locations in the CCV during the period 1950-2009 were examined for the occurrence of lethal maximum temperatures for the uredinia and uredinio-mycelium of this fungus. The lethal upper threshold temperature for the uredinial stage of P.s. tritici, estimated to be 40.5 °C on the basis of data published elsewhere, and the sum, accumulated...

  17. Distribution of the wheat stripe rust and the main influencing factors%平凉市小麦条锈病越夏菌源分布区域精准勘测及主要影响因子研究

    Institute of Scientific and Technical Information of China (English)

    王新俊

    2009-01-01

    通过多年调查研究,明确了当地小麦条锈病菌主要越夏寄主、越夏方式和越夏菌源量的影响因子,精准界定了越夏菌源分布区域;通过对历史资料系统分析,研究筛选出了主要相关因子,采用多元逐步回归方法组建了当地小麦条锈病越夏菌量预测模型,回测准确率为73.91%,对开展其综合治理有积极的指导作用.%After many years' study,the pathogens of local wheat stripe rust and its occurrence rule were found.The distribution areas of the pathogen were also determined.By analyzing historical materials,we chose the main relative factors and constructed the forecasting models for the local wheat stripe rust,which was then tested for its accuracy.

  18. Resistance Potential of Bread Wheat Genotypes Against Yellow Rust Disease Under Egyptian Climate

    Directory of Open Access Journals (Sweden)

    Amer F. Mahmoud

    2015-12-01

    Full Text Available Yellow rust (stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F₈ recombinant inbred lines (RILs derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant and Sakha-69 (susceptible were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 2 <6. However, only 7 RILs showed RRI value <2. Five RILs expressed hypersensitive type of resistance (R against the pathogen and showed the lowest Average Coefficient of Infection (ACI. Bulked segregant analysis (BSA with eight simple sequence repeat (SSR, eight sequence-related amplified polymorphism (SRAP and sixteen random amplified polymorphic DNA (RAPD markers revealed that three SSR, three SRAP and six RAPD markers were found to be associated with the resistance to yellow rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.

  19. Rust essentials

    CERN Document Server

    Balbaert, Ivo

    2015-01-01

    This book is intended for software developers interested in systems level and application programming, and are looking for a quick entry into using Rust and understanding the core features of the framework. It is assumed that you have a basic understanding of Java, C#, Ruby, Python or JavaScript.

  20. 冬小麦品种‘兰天23号’苗期抗条锈性遗传分析%Inheritance of resistance of wheat variety ‘Lantian 23’ against stripe rust at seedling stage

    Institute of Scientific and Technical Information of China (English)

    黄苗苗; 金社林; 李亚凯; 黄瑾; 贾秋珍; 孙振宇; 张勃; 王晓明; 王万军; 曹世勤

    2015-01-01

    2014年在甘肃省农业科学院植物保护研究所兰州温室,进行了‘兰天23号’/‘铭贤169’组合的亲本及其F1、F2、BC1代对条锈菌主要流行小种 CYR32、CYR33及新菌系 G22-9的遗传分析。结果表明,接种 CYR33,F2代植株抗感分离比为144R∶54S,符合3R∶1S 的理论比值;接种 CYR32,F2代植株抗感分离比为62R∶22S,符合3R∶1S的理论比值;接种 G22-9,F2代植株抗感分离比为85R∶24S,符合3R∶1S 的理论比值;F1代植株对供试菌系均表现免疫,BC1代植株抗感分离比均符合1R∶1S 的理论比值,表明‘兰天23号’对3个供试条锈菌系的抗病性均由1对显性抗性基因控制。通过系谱分析推知,该抗病基因来源于抗病亲本‘SXAF4-7’。%The winter wheat variety ‘Lantian 23’is an important cultivar in Gansu Province,China.It was used as male parent and hybridized with the susceptible cultivar ‘Mingxian 1 69’at Gangu Testing Station,Institute of Plant Protection,Gansu Academy of Agricultural Sciences (IPP,GAAS).To study the resistant inheritance of wheat variety ‘Lantian 23’to stripe rust at seedling stage,the P1 ,P2 ,F1 ,F2 and BC1 populations of the crosses with susceptible variety ‘Mingxian 1 69’were inoculated in Lanzhou greenhouses in IPP of GAAS with three races (isolates)of Puccinia striiformis f.sp.tritici ,including CYR33,CYR32,and G22-9.The results showed that the segregation ratio for the cross of ‘Lantian 23 ’and ‘Mingxian 1 69 ’was 144∶54 in F2 plants when tested with CYR33,which was accorded with the expected value for 3R∶1S by Chi-square (χ2 )testing for probability of goodness fit.When tested with CYR32 and G22-9,the segregation ratio for the cross of ‘Lantian 23 ’and‘Mingxian 1 69’were 62∶22 and 85∶24,also accorded with the expected value for 3R∶1S by Chi-square (χ2 )tes-ting for probability of goodness fit.When tested with CYR33,CYR32,and G22-9,F1 populations were immune, and BC1

  1. Genetic analysis and molecular mapping of stripe rust resistance gene in a restore line of Thermo-Photo sensitive hybrid wheat MR168%两系杂交小麦恢复系MR168抗条锈病基因遗传分析及分子标记定位

    Institute of Scientific and Technical Information of China (English)

    任勇; 李生荣; 李俊; 周强; 杜小英; 李太军; 杨武云; 郑有良

    2011-01-01

    小麦条锈病是影响杂交小麦普及推广的重要因素.文章利用基因推导法和SSR分子标记技术,研究了温光型两系杂交小麦恢复系MR168的抗条锈性遗传规律及其控制基因染色体位置.结果表明,MR168对CY29、CY31、CY32、CY33等条锈菌生理小种表现高抗至免疫;对SY95-71/MR168杂交组合的正反交F1、BC1、F2和F3群体分单株接种鉴定显示,MR168对CY32号小种的抗性受1对显性核基因控制,该抗病基因来源于春小麦品种辽春10号.利用集群分离分析法(Bulked segregant analysis,BSA)和简单重复序列(Simple sequence repeat,SSR)分子标记分析抗病亲本MR168、感病亲本SY95-71及183个F2代单株,发现了与MR168抗条锈病基因连锁的5个微卫星标记Xgwm273、Xgwm18、Xbarc187、Xwmc269、Xwmc406,并将该基因初步定位在1BS着丝粒附近,暂命名为YrMR168;构建了包含YrMR168的SSR标记遗传图谱,距离YrMR168最近的两个微卫星位点是Xgwm18和Xbarc18 7,遗传距离分别为1.9 cM和2.4 cM,这两个微卫星标记可用于杂交小麦抗条锈病分子标记辅助育种.%Stripe rust, caused by Puccinia striiformis f. Sp. Tritici, is an important limiting factor to popularize hybrid wheat. The objectives of this study were to map a stripe rust resistance gene in a Chinese thermo-photo-sensitive hybrid wheat restore line MR168 using gene postulation and SSR markers. MR168 was highly resistant to 23 Pst races including CYR29, CYR31, CYR32, and CYR33. The populations F1, BC1, F2, and F3 from the cross between MR168 and SY95-71 (a wheat cultivar susceptible to Pst races) were inoculated with the race of Pst CYR32 of China in greenhouse. MR168 carried a single dominant gene for resistance to CYR32, tentatively designated YrMR168. It originated from Liaochun 10, a spring wheat variety. A total of 183 F2 plants, the resistant and susceptible parents and resistant and susceptible bulks were used for resistance gene mapping with 329 pairs of

  2. Stripe pattern in the intensity profile of collimated soft x-ray beams caused by surface corrugation of the refocusing mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, D., E-mail: schmitz@helmholtz-berlin.de; Siewert, F.; Zeschke, T.

    2015-02-21

    The effect of progress in surface finishing of optical components on the collimated-beam properties of soft x-ray beamlines at synchrotron radiation facilities is demonstrated: a stripe pattern, experimentally observed in the 2D intensity profile of beamlines with optical components manufactured 10–15 years ago, would be strongly attenuated if the existing refocusing mirror was replaced by an ultra-precise mirror manufactured with state-of-the-art of today surface finishing techniques. The observed stripe pattern is not caused by diffraction because its period length did not change with photon energy. Instead it can be explained with geometrical optics and is due to the height profile of the refocusing mirror which has been independently measured with a long trace profiler and used as an input in our raytracing simulations.

  3. Stripe pattern in the intensity profile of collimated soft x-ray beams caused by surface corrugation of the refocusing mirrors

    International Nuclear Information System (INIS)

    The effect of progress in surface finishing of optical components on the collimated-beam properties of soft x-ray beamlines at synchrotron radiation facilities is demonstrated: a stripe pattern, experimentally observed in the 2D intensity profile of beamlines with optical components manufactured 10–15 years ago, would be strongly attenuated if the existing refocusing mirror was replaced by an ultra-precise mirror manufactured with state-of-the-art of today surface finishing techniques. The observed stripe pattern is not caused by diffraction because its period length did not change with photon energy. Instead it can be explained with geometrical optics and is due to the height profile of the refocusing mirror which has been independently measured with a long trace profiler and used as an input in our raytracing simulations

  4. 小麦新抗源CH7103抗条锈基因的遗传及其与已知基因的关系%Inheritance of Stripe Rust Resistance Gene in Wheat Line CH7103 Introgressed from Thinopyrum ponticum and Its Allelism with Known Genes

    Institute of Scientific and Technical Information of China (English)

    白云; 李欣; 张丛卓; 张晓军; 詹海仙; 畅志坚

    2011-01-01

    为了更好地利用小麦条锈病新抗源,以衍生于八倍体小偃麦"小偃7430"的新抗源CH7103为材料,对其抗条锈性及抗病基因的来源、遗传模式和细胞学特征及其与已知抗病基因的关系进行了分析和鉴定.结果表明,CH7103苗期和成株期对条锈菌系条中31、32号生理小种表现免疫或近免疫,与其抗性供体小偃7430及其野生亲本的抗病侵染型相似,而其小麦亲本均感病,说明CH7103对条锈病的抗性来自彭提卡偃麦草.抗×感的F1代均表现免疫,侵染型为0~0;级,且F2、F2∶3、BC1代的抗、感分离比均符合显性单基因控制的分离模式.通过等住性检测,初步明确CH7103含有的抗条锈病基因与已有的抗CYR32小种的基因Yr5、Yr10、Yr15、Yr41不存在等位关系,可能属于新的抗小麦条锈病基因.细胞学研究表明,CH7103及其与小麦品种"中国春"等杂种F1的染色体数目均为2n=42,绝大多数花粉母细胞具有2n=21Ⅱ的配对构型,并能与小麦染色体完好配对.说明CH7103不含较大的外源染色体片段,是一个携带偃麦草抗条锈病基因的异源渐渗系.%CH7103 is a Thinopyrum ponticurn-derived wheat breeding line, which was resistant to stripe rust and powdery mildew, and derived from cross between partial amphiploid Xiaoyan7430 and wheat susceptible cultivars. This study was made to determine the inheritance of resistance to stripe rust in CH7103, and to characterize the origin of the resistance gene and its allelism with known genes, The disease screening demonstrated that CH7103 and its donor Xiaoyan7430 as well as the wild parent were resistant at the seedling and adult stages to CYR31 and CYR32 of the prevalent and most widely virulent in China, whereas all the wheat parents involved were susceptible, indicating that the stripe rust resistance in CH7103 was possibly derived from Th. ponticum. Genetic analysis on the F1,F2, F2∶3 and BC1 populations from stripe rust resistant

  5. Primeira ocorrência de ferrugem em capim-limão causada por Puccinia cymbopogonis no Brasil First report of the lemongrass rust fungi caused by Puccinia cymbopogonis in Brazil

    Directory of Open Access Journals (Sweden)

    João Batista Vida

    2006-03-01

    Full Text Available È registrada a primeira ocorrência de ferrugem em capim-limão (Cymbopogon citratus (DC. Stapf, causada por Puccinia cymbopogonis Mass., no Brasil, Estado do Paraná.It is reported the first occurrence of the lemongrass (Cymbopogon citratus (DC. Stapf rust fungi caused by Puccinia cymbopogonis Mass. in Brazil, State of Paraná.

  6. Did transmission of Helicobacter pylori from humans cause a disease outbreak in a colony of Stripe-faced Dunnarts (Sminthopsis macroura?

    Directory of Open Access Journals (Sweden)

    Every Alison L

    2011-02-01

    Full Text Available Abstract Since the discovery that Helicobacter pylori causes a range of pathologies in the stomachs of infected humans, it has become apparent that Helicobacters are found in a diverse range of animal species where they are frequently associated with disease. In 2003 and 2004, there were two outbreaks of increased mortality associated with gastric bleeding and weight-loss in a captive colony of the Australian marsupial, the Stripe-faced Dunnart (Sminthopsis macroura. The presence of gastric pathology led to an investigation of potential Helicobacter pathogenesis in these animals. Histological examination revealed the presence of gastritis, and PCR analysis confirmed the presence of Helicobacter infection in the stomachs of these marsupials. Surprisingly, sequencing of 16S rRNA from these bacteria identified the species as H. pylori and PCR confirmed the strain to be positive for the important pathogenesis factor, cagA. We therefore describe, for the first time, an apparent reverse zoonotic infection of Stripe-faced Dunnarts with H. pylori. Already prone to pathological effects of stress (as experienced during breeding season, concomitant H. pylori infection appears to be a possible essential but not sufficient co-factor in prototypic gastric bleeding and weight loss in these marsupials. The Stripe-faced Dunnart could represent a new model for investigating Helicobacter-driven gastric pathology. Infections from their human handlers, specifically of H. pylori, may be a potential risk to captive colonies of marsupials.

  7. Cytological effect of Tilt 250 EC in the successive phases of the Triticale rust disease process caused by Puccinia recondita f. sp. tritici

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    Krystyna Brzezicka-Szymczyk

    2014-02-01

    Full Text Available The disease process caused by rust (Puccinia recondita f. sp. tritici in Triticale (Triticale-Wittmack cv. Bolero and the effect of the application of the propikonazole - Tilt 250 EC are described. In plants not protected chemically one could observe the whole pathogen developmental cycle ending with the appearance of uredinia with urediniospores. The highest pathogen susceptibility to chemical agent was observed at the time of inoculation, during incubation and at the beginning of the actual disease. By inhibiting the ergosterol biosynthesis in the fungus cells the preparation (propikonazole inhibited the development of the intra- and extracellular mycelium. The mycelium degeneration manifested itself by the irregular growth of intercellular hyphae, perforation of septa, homogenization of protoplasts and cell collapse. The thickening of the cell wall, modification of the perihaustorial space and protoplast obliteration were observed in the haustoria.

  8. Cytogenetic Characteristics and Resistance to Stripe Rust of Derivatives from Hybrid between Triticum monococcum and Wild Oat%一粒小麦×野燕麦衍生系细胞学特征及条锈病抗性鉴定

    Institute of Scientific and Technical Information of China (English)

    王秀波; 王琪琳; 苟红亮; 韩德俊; 康振生

    2012-01-01

    在一粒小麦与葡萄牙野燕麦远缘杂交后代中,选育了5个形态学稳定的抗条锈病衍生系(‘一粒葡')YLP1、YLP-7、YLP-9、YLP-13和YLP-16,为筛选含有外源染色体且抗性优良的植株,对该衍生系的细胞学特征和抗病性进行了鉴定.细胞学初步鉴定表明:根尖染色体数目均为2n=42,花粉母细胞减数分裂中期Ⅰ染色体构型为2n=21Ⅱ;5个选系与‘中国春’杂交F1花粉母细胞减数分裂中期Ⅰ的异常细胞构型率为16%~50%;初步鉴定这5个‘一粒葡’材料均为易位系,验证了‘一粒葡’是远缘杂交的后代.用9个条锈菌小种分别对9个株系进行苗期抗病性鉴定,有5个株系YLP-1-4、YLP-7、YLP-9-1、YLP-9-3、YLP-16-1对所有参试小种都表现为高抗,且与已知的Yr5、Yr10、Yr15、Yr24/Yr26基因不同,表明‘一粒葡’中可能含有新的抗病基因,可作为抗源用于小麦抗病育种.%Five lines of YLP, YLP-1, YLP-7, YLP-9, YLP-13 and YLP-16,the distant hybridization generations from Triticum monococcum and Avena fatua L. , which stability resistance to Puccinia striiformis f. sp. tritici. (Pst) were selected as experiment materials. In order to choose containing alien chromosomes and the strongest resistant plants, we made cytogenetic analysis and resistance evaluation of these hybrid derivatives. 2n= 42 chromosomes were observed after identification root tip in cytology and the chromosome configuration of most pollen mother cell during metaphase of meiosis I were 2n = 21 Ⅱ ;In the pollen mother cell of FL plants from five derivatives and Chinese Spring,the frequency of abnormal cells were 16% ~50%. Primary identification showed that these materials were translocation lines. YLP were verified generations from distant hybridization. The resistance of these selected nine lines to nine races of stripe rust were done during seedling stage,five lines (YLP-1-4, YLP-7, YLP-9-1 .YLP-9-3 and YLP-16-1) resistant to all of

  9. 平凉市小麦条锈病越冬菌源分布区域勘定及主要影响因子研究%Distribution area of overwintering pathogen source of wheat stripe rust and its main affecting factors in Pingliang

    Institute of Scientific and Technical Information of China (English)

    王新俊

    2014-01-01

    Through years of investigation,we confirmed that overwintering area of wheat stripe rust in Pingliang City was located in the wheat planting regions under altitude of 1 980 m and its main overwintering area distributed at altitude below 1 750 m.Based on comprehensive analysis of historical data for wheat stripe rust during 27 years,the main factors affecting the amount of overwintering pathogen were selected,including the occurrence degree on autumn seedlings of the year,total precipitation from November to February in winter,average temperature in January next year and days of snow covering before January 31 next year.Using multiple stepwise regression method,a prediction model for the local overwintering pathogens were set up,with back measurement accuracy of 72%.%通过多年调查研究,明确了甘肃省平凉市小麦条锈病菌越冬区域为海拔1980 m 以下的小麦种植区,主要越冬区域在海拔1750 m 以下;在对该市27年小麦条锈病历史资料系统分析的基础上,研究筛选出了当年秋苗发病程度、冬季11月-翌年2月降水总量、翌年1月份平均气温、翌年1月31日前积雪日数等小麦条锈病越冬菌量的主要影响因子,采用多元逐步回归方法组建了当地小麦条锈病越冬菌量预测模型,回测准确率为72%,对开展其综合治理有积极的指导作用。

  10. Over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici in the California Central valley: A case study Supervivencia estival de la roya estriada (Puccinia striiformis f.sp. tritici del trigo en el Valle Central de California: Estudio de caso

    Directory of Open Access Journals (Sweden)

    Huib Tollenaar

    2012-12-01

    Full Text Available To study the over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici in the California Central Valley (CCV, temperature records from various locations in the CCV during the period 1950-2009 were examined for the occurrence of lethal maximum temperatures for the uredinia and uredinio-mycelium of this fungus. The lethal upper threshold temperature for the uredinial stage of P.s. tritici, estimated to be 40.5 °C on the basis of data published elsewhere, and the sum, accumulated during ten consecutive days, of the respective lethal temperature quotients (ALTQio, accounting for the partial lethal effect of the daily ambient temperatures between 30 and 40.5 °C on the uredinial stage of P.s. tritici, were used as yardsticks for thermal lethality. The results indicate that, in these 60 yr, the uredinia and the uredinio-mycelium of P.s. tritici could not possibly have over-summered at any of the locations studied. The Sierra Nevada Mountains, together with the Tulelake Basin and the coastal zone of the Pacific Ocean are the only two areas in California with appropriate environmental conditions for the summer-survival of the uredinial stage of stripe rust. Therefore, it is presumed that the inoculum for the initial infections of P.s. tritici in wheat fields in the CCV during the following growing season originates in either one or both of these areas, although, a potential third source of inoculum for the initial infections of stripe rust in the CCV could also be involved. Namely, the possible presence of telia with viable teliospores of P.s. tritici in autumn on straw of the threshed wheat fields or on volunteer wheat plants in the CCV, in conjunction with the accidental concurrence of nearby stripe rust susceptible barberry (Berberis spp., could lead to the development of alternative, endogenous sources of inoculum in the CCV.Para estudiar la supervivencia estival de la roya estriada (Puccinia striiformis f.sp. tritici del trigo

  11. Leaf Rust of Wheat: Pathogen Biology, Variation and Host Resistance

    Directory of Open Access Journals (Sweden)

    James Kolmer

    2013-01-01

    Full Text Available Rusts are important pathogens of angiosperms and gymnosperms including cereal crops and forest trees. With respect to cereals, rust fungi are among the most important pathogens. Cereal rusts are heteroecious and macrocyclic requiring two taxonomically unrelated hosts to complete a five spore stage life cycle. Cereal rust fungi are highly variable for virulence and molecular polymorphism. Leaf rust, caused by Puccinia triticina is the most common rust of wheat on a worldwide basis. Many different races of P. triticina that vary for virulence to leaf rust resistance genes in wheat differential lines are found annually in the US. Molecular markers have been used to characterize rust populations in the US and worldwide. Highly virulent races of P. triticina are selected by leaf rust resistance genes in the soft red winter wheat, hard red winter wheat and hard red spring wheat cultivars that are grown in different regions of the US. Cultivars that only have race-specific leaf rust resistance genes that are effective in seedling plants lose their effective resistance and become susceptible within a few years of release. Cultivars with combinations of race non-specific resistance genes have remained resistant over a period of years even though races of the leaf rust population have changed constantly.

  12. Holographic stripes.

    Science.gov (United States)

    Rozali, Moshe; Smyth, Darren; Sorkin, Evgeny; Stang, Jared B

    2013-05-17

    We construct inhomogeneous asymptotically anti-de Sitter black hole solutions corresponding to the spontaneous breaking of translational invariance and the formation of striped order in the boundary field theory. We find that the system undergoes a second-order phase transition in both the fixed density and fixed chemical potential ensembles, for sufficiently large values of the axion coupling. We investigate the phase structure as a function of the temperature, axion coupling, and the stripe width. The bulk solutions have striking geometrical features related to a magnetoelectric effect associated with the existence of a near-horizon topological insulator. At low temperatures, the horizon becomes highly inhomogeneous and tends to pinch off. PMID:25167395

  13. Glyphosate Control of Orange and Brown Rusts in Glyphosate-Sensitive Sugarcane Cultivars

    Science.gov (United States)

    Technical Abstract: Brown and orange rust diseases cause substantial yield reductions on sugarcane (Saccharum spp.) in Florida and other regions where sugarcane is grown. Brown rust caused by Puccinia melanocephala Syd. & P. Syd has been present in Florida since 1978 and orange rust caused by Pucci...

  14. Specificity of a Rust Resistance Suppressor on 7DL in the Spring Wheat Cultivar Canthatch.

    Science.gov (United States)

    Talajoor, Mina; Jin, Yue; Wan, Anmin; Chen, Xianming; Bhavani, Sridhar; Tabe, Linda; Lagudah, Evans; Huang, Li

    2015-04-01

    The spring wheat 'Canthatch' has been shown to suppress stem rust resistance genes in the background due to the presence of a suppressor gene located on the long arm of chromosome 7D. However, it is unclear whether the suppressor also suppresses resistance genes against leaf rust and stripe rust. In this study, we investigated the specificity of the resistance suppression. To determine whether the suppression is genome origin specific, chromosome location specific, or rust species or race specific, we introduced 11 known rust resistance genes into the Canthatch background, including resistance to leaf, stripe, or stem rusts, originating from A, B, or D genomes and located on different chromosome homologous groups. F1 plants of each cross were tested with the corresponding rust race, and the infection types were scored and compared with the parents. Our results show that the Canthatch 7DL suppressor only suppressed stem rust resistance genes derived from either the A or B genome, and the pattern of the suppression is gene specific and independent of chromosomal location.

  15. Spatial scaling relationships for spread of disease caused by a wind-dispersed plant pathogen

    OpenAIRE

    Mundt, Christopher C.; Sackett, Kathryn E.

    2012-01-01

    Spatial scale is of great importance to understanding the spread of organisms exhibiting long-distance dispersal (LDD). We tested whether epidemics spread in direct proportion to the size of the host population and size of the initial disease focus. This was done through analysis of a previous study of the effects of landscape heterogeneity variables on the spread of accelerating epidemics of wheat (Triticum aestivum) stripe rust, caused by the fungus Puccinia striiformis f. sp. tritici. End-...

  16. 75 FR 54461 - Black Stem Rust; Additions of Rust-Resistant Varieties

    Science.gov (United States)

    2010-09-08

    ... States. The disease is caused by a fungus that reduces the quality and yield of infected wheat, oat... Research Service of the United States Department of Agriculture (USDA) at its Cereal Rust Laboratory in...

  17. Inheritance of Resistance Chinese Wheat Stripe Rust Races CYR30 and CYR31 in Durum Wheat Line SWAHEN 3%硬粒小麦SWAHEN 3抗条锈(条中30、31)性状的遗传分析

    Institute of Scientific and Technical Information of China (English)

    杨武云; 余毅; 胡晓蓉; 杨家秀; 颜济; 杨俊良

    2001-01-01

    硬粒小麦SWAHEN 3成株期对中国条锈病新小种条中30(CYR30)和条中31(CYR31)免疫-高抗。为明确SWAHEN 3抗条锈性状的遗传规律,将SWAHEN 3与高感硬粒小麦品种Kappli杂交,获得杂种F1、F2群体;将SWAHEN 3与川育12等5个四川高感普通小麦品种杂交,获得杂种F1。对抗×感硬粒小麦杂种F1、F2群体分小种(CYR30和CYR31)接种鉴定,结果表明,杂种F1抗性反应与抗病亲本SWAHEN 3一致,为免疫-高抗;杂种F2群体中免疫-高抗单株与抗-高感单株之比符合两对显性互补基因分离比例9∶7。对抗病硬粒小麦×感病普通小麦杂种F1分小种(CYR30和CYR31)接种鉴定,结果表明,杂种F1抗性反应也与抗病亲本SWAHEN 3一致,为免疫-高抗。分析表明,SWAHEN 3对条中30、31的抗性受两对显性互补基因控制,其抗性基因能在与四川高产小麦的杂交后代中完全表达。%SWAHEN 3, a durum wheat line introduced from CIMMYT, was highly resistant to Chinese new stripe rust races CYR30 and CYR31 at adult stage. In order to determince the inheritance of resistance in it, SWAHEN 3 was crossed with a highly susceptible durum variety Kappli and five highly susceptible cultivars of Sichuan common wheat. Analysis of data from F1~F2 of cross between SWAHEN 3 and Kappli revealed that the resistance to CYR30 and CYR31 of SWAHEN 3 was controlled by two complementary dominant genes. And all of F1 hybrids of SWAHEN 3 crossed with five Sichuan common wheat cultivars were immune to the two Chinese stripe rust races. This result could indicated the resistance of SWAHEN 3 could be expressed in common wheat.

  18. Limited divergence among populations of rice striped stem borer in southeast China caused by gene flow: Implications for resistance management

    Institute of Scientific and Technical Information of China (English)

    Chao YANG; Xiao YANG; Qiang FU; Kai XU; Bao-Rong LU

    2012-01-01

    Rice striped stem borer (RSSB,Chilo suppressalis) is a serious lepidopteron pest occurring in rice ecosystems of Asia and Europe.Genetically modified (GM) insect-resistant Bt rice has been developed to deter lepidopteron pests including RSSB.The concern of resistance evolution to the Bt toxin by the pests under commercial cultivation of GM Bt rice and the need of effective management of the resistance encourage the studies of genetic variation and divergence,as well as gene flow of RSSB populations.We analyzed 13 RSSB populations fed on water-oats or rice plants,respectively,from southeast China applying the fluorescent amplified fragment length polymorphism fingerprints.A generally moderate level of genetic variation was detected in the populations,as estimated by Nei's genetic diversity (0.27) and Shannon's index (0.42).The FsT- and AMOVA values indicated a low level (~ 12%) of genetic divergence among the RSSB populations.A relatively frequent gene flow (an average Nm =2.62) was detected among the 12 RSSB populations,which may explain the limited genetic divergence among the rice-feeding populations.This explanation gains support by the assignment test of the corresponding populations,suggesting that a considerable proportion of individuals was contributed from non-native populations.Our results revealed that the moderate level of genetic diversity combined with relatively frequent gene flow among RSSB populations across a large geographical range may slow down the resistance evolution of the RSSB populations,given that a proper measure of resistance management is taken.

  19. Comparative transcript profiling of Lr1- and Lr34-mediated leaf rust resistance in wheat

    Science.gov (United States)

    Leaf rust caused by the fungus Puccinia triticina is a widespread disease of wheat. Host resistance strategies to control leaf rust have relied upon race-specific and non-race specific leaf rust resistance (Lr) genes. Although race-specific Lr genes are efficient in halting pathogen growth, high lev...

  20. The Big Rust and the Red Queen: Long-Term Perspectives on Coffee Rust Research.

    Science.gov (United States)

    McCook, Stuart; Vandermeer, John

    2015-09-01

    Since 2008, there has been a cluster of outbreaks of the coffee rust (Hemileia vastatrix) across the coffee-growing regions of the Americas, which have been collectively described as the Big Rust. These outbreaks have caused significant hardship to coffee producers and laborers. This essay situates the Big Rust in a broader historical context. Over the past two centuries, coffee farmers have had to deal with the "curse of the Red Queen"-the need to constantly innovate in the face of an increasing range of threats, which includes the rust. Over the 20th century, particularly after World War II, national governments and international organizations developed a network of national, regional, and international coffee research institutions. These public institutions played a vital role in helping coffee farmers manage the rust. Coffee farmers have pursued four major strategies for managing the rust: bioprospecting for resistant coffee plants, breeding resistant coffee plants, chemical control, and agroecological control. Currently, the main challenge for researchers is to develop rust control strategies that are both ecologically and economically viable for coffee farmers, in the context of a volatile, deregulated coffee industry and the emergent challenges of climate change. PMID:26371395

  1. The Big Rust and the Red Queen: Long-Term Perspectives on Coffee Rust Research.

    Science.gov (United States)

    McCook, Stuart; Vandermeer, John

    2015-09-01

    Since 2008, there has been a cluster of outbreaks of the coffee rust (Hemileia vastatrix) across the coffee-growing regions of the Americas, which have been collectively described as the Big Rust. These outbreaks have caused significant hardship to coffee producers and laborers. This essay situates the Big Rust in a broader historical context. Over the past two centuries, coffee farmers have had to deal with the "curse of the Red Queen"-the need to constantly innovate in the face of an increasing range of threats, which includes the rust. Over the 20th century, particularly after World War II, national governments and international organizations developed a network of national, regional, and international coffee research institutions. These public institutions played a vital role in helping coffee farmers manage the rust. Coffee farmers have pursued four major strategies for managing the rust: bioprospecting for resistant coffee plants, breeding resistant coffee plants, chemical control, and agroecological control. Currently, the main challenge for researchers is to develop rust control strategies that are both ecologically and economically viable for coffee farmers, in the context of a volatile, deregulated coffee industry and the emergent challenges of climate change.

  2. Gene discovery in EST sequences from the wheat leaf rust fungus Puccinia triticina sexual spores, asexual spores and haustoria, compared to other rust and corn smut fungi

    Directory of Open Access Journals (Sweden)

    Wynhoven Brian

    2011-03-01

    Full Text Available Abstract Background Rust fungi are biotrophic basidiomycete plant pathogens that cause major diseases on plants and trees world-wide, affecting agriculture and forestry. Their biotrophic nature precludes many established molecular genetic manipulations and lines of research. The generation of genomic resources for these microbes is leading to novel insights into biology such as interactions with the hosts and guiding directions for breakthrough research in plant pathology. Results To support gene discovery and gene model verification in the genome of the wheat leaf rust fungus, Puccinia triticina (Pt, we have generated Expressed Sequence Tags (ESTs by sampling several life cycle stages. We focused on several spore stages and isolated haustorial structures from infected wheat, generating 17,684 ESTs. We produced sequences from both the sexual (pycniospores, aeciospores and teliospores and asexual (germinated urediniospores stages of the life cycle. From pycniospores and aeciospores, produced by infecting the alternate host, meadow rue (Thalictrum speciosissimum, 4,869 and 1,292 reads were generated, respectively. We generated 3,703 ESTs from teliospores produced on the senescent primary wheat host. Finally, we generated 6,817 reads from haustoria isolated from infected wheat as well as 1,003 sequences from germinated urediniospores. Along with 25,558 previously generated ESTs, we compiled a database of 13,328 non-redundant sequences (4,506 singlets and 8,822 contigs. Fungal genes were predicted using the EST version of the self-training GeneMarkS algorithm. To refine the EST database, we compared EST sequences by BLASTN to a set of 454 pyrosequencing-generated contigs and Sanger BAC-end sequences derived both from the Pt genome, and to ESTs and genome reads from wheat. A collection of 6,308 fungal genes was identified and compared to sequences of the cereal rusts, Puccinia graminis f. sp. tritici (Pgt and stripe rust, P. striiformis f. sp

  3. Prospects for advancing defense to cereal rusts through genetical genomics.

    Science.gov (United States)

    Ballini, Elsa; Lauter, Nick; Wise, Roger

    2013-01-01

    Rusts are one of the most severe threats to cereal crops because new pathogen races emerge regularly, resulting in infestations that lead to large yield losses. In 1999, a new race of stem rust, Puccinia graminis f. sp. tritici (Pgt TTKSK or Ug99), was discovered in Uganda. Most of the wheat and barley cultivars grown currently worldwide are susceptible to this new race. Pgt TTKSK has already spread northward into Iran and will likely spread eastward throughout the Indian subcontinent in the near future. This scenario is not unique to stem rust; new races of leaf rust (Puccinia triticina) and stripe rust (Puccinia striiformis) have also emerged recently. One strategy for countering the persistent adaptability of these pathogens is to stack complete- and partial-resistance genes, which requires significant breeding efforts in order to reduce deleterious effects of linkage drag. These varied resistance combinations are typically more difficult for the pathogen to defeat, since they would be predicted to apply lower selection pressure. Genetical genomics or expression Quantitative Trait Locus (eQTL) analysis enables the identification of regulatory loci that control the expression of many to hundreds of genes. Integrated deployment of these technologies coupled with efficient phenotyping offers significant potential to elucidate the regulatory nodes in genetic networks that orchestrate host defense responses. The focus of this review will be to present advances in genetical genomic experimental designs and analysis, particularly as they apply to the prospects for discovering partial disease resistance alleles in cereals.

  4. Experts note possible discovery of Asian Soybean Rust spores

    OpenAIRE

    Johnson, Mary Ann

    2005-01-01

    Virginia Tech scientists say that there has been a change in the status of the fungus causing Asian Soybean Rust but that the new information is still too preliminary for any action on the part of the Commonwealth's soybean producers.

  5. Major gene for field stem rust resistance co-locates with resistance gene Sr12 in "Thatcher" wheat

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effecting stem rust resistance genes. "Thatcher" wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was ...

  6. Spread, genetic variation and methods for the detection of Puccinia kuehnii, the causal agent of sugarcane orange rust.

    Science.gov (United States)

    Sugarcane is susceptible to infection by two rust pathogens, Puccinia melanocephala and P. kuehnii, causing brown and orange rust, respectively. Orange rust of sugarcane was first reported in the Western hemisphere in Florida in July 2007. The pathogen was found to be distributed widely throughout t...

  7. InIdentification and characterization of pathotypes in Puccinia horiana, a rust pathogen of Chrysanthemum x morifolium

    NARCIS (Netherlands)

    Backer, de M.; Alaei, H.; Bockstaele, van E.; Roldan-Ruiz, I.; Lee, van der T.; Maes, M.; Heungens, K.

    2011-01-01

    Puccinia horiana is the causal agent of chrysanthemum white rust or Japanese rust. This microcyclic autoecious rust has a quarantine status and can cause major damage in the commercial production of Chrysanthemum x morifolium. Given the international and often trans-continental production of plantin

  8. Wheat production and wheat rust management in Canada%加拿大小麦生产和锈病防治

    Institute of Scientific and Technical Information of China (English)

    Allen G. Xue; Dawn T. Chi; 张淑珍; 李卓夫; 徐鹏飞; 姜良宇; 范素杰; 王欣

    2012-01-01

    Wheat is Canada's largest crop with most of the production in the western Canadian Prairie Provinces of Manitoba, Saskatchewan and Alberta. There were approximately ten million hm2 seeded to wheat in Canada, including seven million hm2 of hexaploid spring wheat (Triticum aestivum L), two million hm2 of durum wheat (T. Turgkjum L ssp. Durum (Desf.) Husn.), and one million hm2 of winter wheat (T. Aestivum). Within hexaploid wheat there has been diversification into a number of market classes based on differentend-use quality criteria. The predominant spring bread wheat class has been the Canada Western Red Spring (CWRS) class. Historically, the disease of major concern in wheat was stem rust, caused by Pucdnia graminis f. Sp. Tritid. The first significant stem rust resistant cuttivar in Canada was Thatcher, grown extensively from 1939 until the early 1970s. Thatcher, however, was very susceptible to leaf rust, caused by Pucdnia triticina. Over the years, improved resistance to both stem and leaf rust was achieved with the release of cultivars with additional genes for resistance, primarily Sr2, Sr6, Sr7a, Sr9b, Lr13, Lr14a, Lr16, and Lr34. The genetic resistance has adequately controlled stem rust but leaf rust continues to cause significant losses, partially due to changes in the P. Triticina population which reduced the effectiveness of resistance genes such as Lr13 and Lr16. Stripe rust on wheat, caused by Pucdnia striiformis f. Sp. Tritid, was historically a problem under irrigation in southern Alberta, but since 2000 it has been found annually in the central Canadian prairies and southern Ontario. The genetic basis of resistance to stripe rust in most Canadian wheat cultivars has not been determined, although VTI8 provides partial resistance in many cultivars. In the future, other rust diseases such as wheat stripe rust, or highly virulent new pathotypes of current rust pathogens, such as P. Graminis f. Sp. Tritid race Ug-99, may pose new threats to cereal

  9. Nonhost resistance to rust pathogens – a continuation of continua

    Directory of Open Access Journals (Sweden)

    Jan eBettgenhaeuser

    2014-12-01

    Full Text Available The rust fungi (order: Pucciniales are a group of widely distributed fungal plant pathogens, which can infect representatives of all vascular plant groups. Rust diseases significantly impact several crop species and considerable research focuses on understanding the basis of host specificity and nonhost resistance. Like many pathogens, rust fungi vary considerably in the number of hosts they can infect, such as wheat leaf rust (Puccinia triticina, which can only infect species in the genera Triticum and Aegilops, whereas Asian soybean rust (Phakopsora pachyrhizi is known to infect over 95 species from over 42 genera. A greater understanding of the genetic basis determining host range has the potential to identify sources of durable resistance for agronomically important crops. Delimiting the boundary between host and nonhost has been complicated by the quantitative nature of phenotypes in the transition between these two states. Plant-pathogen interactions in this intermediate state are characterized either by (1 the majority of accessions of a species being resistant to the rust or (2 the rust only being able to partially complete key components of its life cycle. This leads to a continuum of disease phenotypes in the interaction with different plant species, observed as a range from compatibility (host to complete immunity within a species (nonhost. In this review we will highlight how the quantitative nature of disease resistance in these intermediate interactions is caused by a continuum of defense barriers, which a pathogen needs to overcome for successfully establishing itself in the host. To illustrate continua as this underlying principle, we will discuss the advances that have been made in studying nonhost resistance towards rust pathogens, particularly cereal rust pathogens.

  10. Advances in Localization and Molecular Markers of Wheat Leaf Rust Resistance Genes

    Institute of Scientific and Technical Information of China (English)

    YANG Wen-xiang; LIU Da-qun

    2004-01-01

    Genetic resistance is the most economical method of reducing yield losses caused by wheat leaf rust. To identify the leaf rust resistance genes in commonly used parental germplasm and released cultivars become very important for utilizing the genetic resistance tc wheat leaf rust fully. Up to date, about 90 leaf rust resistance genes have been found,of which 51 genes have been located and mapped to special chromosomes, and 56 genes have been designated officially according to the standards set forth in the Catalogue of Gene Symbols for wheat. Twenty-four wheat leaf rust resistance genes have been developed for their molecular markers. It is very important to isolate, characterize, and map leaf rust resistance genes due to the resistance losses of the genes caused by the pathogen continuously.

  11. Wheat Rust Toolbox Related to New Initiatives on Yellow Rust

    DEFF Research Database (Denmark)

    Hansen, Jens Grønbech; Lassen, Poul

    of interactive maps; including information on surveillance (disease data over years and across countries for all three rusts) and graphs and maps indicating the distribution of UG99 and related pathotypes. Graphs and maps are integrated with, and disseminated, via the Rust SPORE web portal at FAO (http...... as several other Institutions and information platforms in the Durable Rust Resistance in Wheat project under the BGRI. From the outset the databases and information tools were developed to handle all three rust types. The EuroWheat platform already contains data on yellow rust pathotypes from Europe (1993...... – 2009), and as soon as possible this will be expanded to cover all global yellow rust data available via the GRRC. The presentation will focus on experiences from the previous work on global databases and web based information systems, as well as propose ideas how the toolbox can be helpful regarding...

  12. Transformation of the flax rust fungus, Melampsora lini: selection via silencing of an avirulence gene

    OpenAIRE

    Lawrence, Gregory J.; Dodds, Peter N.; Ellis, Jeffrey G.

    2009-01-01

    Rust fungi cause devastating diseases on many important food crops, with a damaging stem rust epidemic currently affecting wheat production in Africa and the Middle East. These parasitic fungi propagate exclusively on plants, precluding the use of many biotechnological tools available for other culturable fungi. In particular the lack of a stable transformation system has been an impediment to the genetic manipulation required for molecular analysis of rust pathogenicity. We have developed an...

  13. Disease management of leek rust, a study at field, farm and regional level.

    NARCIS (Netherlands)

    Jong, de P.D.

    1995-01-01

    Leek rust, caused by Puccinia allii Rud., is an important disease of leek ( Allium porrum L.) in the Netherlands. The quality decrease of the product associated with a light infestation of leek rust may cause severe economic loss to the grower. The aim of this study is to develop an improved pathosy

  14. First report of Pantoea ananatis (Syn. Erwinia uredovora) being associated with peanut rust in Georgia

    Science.gov (United States)

    Peanut rust is caused by the fungus Puccinia arachidis. This disease, if not treated can cause severe damage and defoliation. While sequencing DNA of urediniospores of the rust fungus, BLAST analysis detected many sequences corresponding to the bacterial species Pantoea ananatis. This bacterium, ...

  15. Reaction of peanut cultivars to late leafspot and rust

    Directory of Open Access Journals (Sweden)

    Nimitr Vorasoot

    2003-05-01

    Full Text Available Late leafspot caused by Phaeoisariopsis personata (Berk. & M.A. Curtis van Arx and rust caused by Puccinia arachidis Speg. are among the most serious diseases of peanut. Although fungicide application is effective in controlling the diseases, its high cost is considered uneconomical in many developing countries. In this situation, the use of resistant cultivars offers a better alternative. The objective of this study was to evaluate seven peanut cultivars for their resistances to late leafspot and rust. Peanut cultivars were planted in a randomized complete block design (RCBD with 4 replications at Khon Kaen University Experimental Farm. Natural infection of late leafspot and rust were allowed. Disease score, sporulation index and lesion number per 100 cm2 of leaf area were recorded as the resistance parameters of both diseases. Pod yield, seed yield, shelling percentage, pod number per plant and pod length were also measured. NC 17135 was the most resistant to late leafspot and moderately resistant to rust. NC 17090 was the most resistant to rust but susceptible to late leafspot. NC 17135 and NC 17090 should be recommended as sources of late leafspot and rust resistance, respectively. The two Thai released cultivars, Tainan 9 and Lampang were highly susceptible to both diseases.

  16. Prospects for Advancing Defense to Cereal Rusts through Genetical Genomics

    Directory of Open Access Journals (Sweden)

    Elsa eBallini

    2013-05-01

    Full Text Available Rusts are one of the most severe threats to cereal crops because new pathogen races emerge regularly, resulting in infestations that lead to large yield losses. In 1999, a new race of stem rust, Puccinia graminis f. sp. tritici (Pgt TTKSK or Ug99, was discovered in Uganda. Most of the wheat and barley cultivars grown currently worldwide are susceptible to this new race. Pgt TTKSK has already spread northward into Iran and will likely spread eastward throughout the Indian subcontinent in the near future. This scenario is not unique to stem rust; new races of leaf rust (Puccinia triticina and stripe rust (Puccinia striiformis have also emerged recently. One strategy for countering the persistent adaptability of these pathogens is to stack complete- and partial-resistance genes, which requires significant breeding efforts in order to reduce deleterious effects of linkage drag. These varied resistance combinations are typically more difficult for the pathogen to defeat, since they would be predicted to apply lower selection pressure. Genetical genomics or expression Quantitative Trait Locus (eQTL analysis enables the identification of regulatory loci that control the expression of many to hundreds of genes. Integrated deployment of these technologies coupled with efficient phenotyping offers significant potential to elucidate the regulatory nodes in genetic networks that orchestrate host defense responses. The focus of this review will be to present advances in genetical genomic experimental designs and analysis, particularly as they apply to the prospects for discovering partial disease resistance alleles in cereals.

  17. Effector proteins of rust fungi

    Directory of Open Access Journals (Sweden)

    Ben ePetre

    2014-08-01

    Full Text Available Rust fungi include many species that are devastating crop pathogens. To develop resistant plants, a better understanding of rust virulence factors, or effector proteins, is needed. Thus far, only six rust effector proteins have been described: AvrP123, AvrP4, AvrL567, AvrM, RTP1 and PGTAUSPE-10-1. Although some are well established model proteins used to investigate mechanisms of immune receptor activation (avirulence activities or entry into plant cells, how they work inside host tissues to promote fungal growth remains unknown. The genome sequences of four rust fungi (two Melampsoraceae and two Pucciniaceae have been analyzed so far. Genome-wide analyses of these species, as well as transcriptomics performed on a broader range of rust fungi, revealed hundreds of small secreted proteins considered as rust candidate secreted effector proteins (CSEPs. The rust community now needs high-throughput approaches (effectoromics to accelerate effector discovery/characterization and to better understand how they function in planta. However, this task is challenging due to the non-amenability of rust pathosystems (obligate biotrophs infecting crop plants to traditional molecular genetic approaches mainly due to difficulties in culturing these species in vitro. The use of heterologous approaches should be promoted in the future.

  18. Effector proteins of rust fungi.

    Science.gov (United States)

    Petre, Benjamin; Joly, David L; Duplessis, Sébastien

    2014-01-01

    Rust fungi include many species that are devastating crop pathogens. To develop resistant plants, a better understanding of rust virulence factors, or effector proteins, is needed. Thus far, only six rust effector proteins have been described: AvrP123, AvrP4, AvrL567, AvrM, RTP1, and PGTAUSPE-10-1. Although some are well established model proteins used to investigate mechanisms of immune receptor activation (avirulence activities) or entry into plant cells, how they work inside host tissues to promote fungal growth remains unknown. The genome sequences of four rust fungi (two Melampsoraceae and two Pucciniaceae) have been analyzed so far. Genome-wide analyses of these species, as well as transcriptomics performed on a broader range of rust fungi, revealed hundreds of small secreted proteins considered as rust candidate secreted effector proteins (CSEPs). The rust community now needs high-throughput approaches (effectoromics) to accelerate effector discovery/characterization and to better understand how they function in planta. However, this task is challenging due to the non-amenability of rust pathosystems (obligate biotrophs infecting crop plants) to traditional molecular genetic approaches mainly due to difficulties in culturing these species in vitro. The use of heterologous approaches should be promoted in the future.

  19. Rust fungi and global change.

    Science.gov (United States)

    Helfer, Stephan

    2014-02-01

    Rust fungi are important components of ecological communities and in ecosystem function. Their unique life strategies as biotrophic pathogens with complicated life cycles could make them vulnerable to global environmental change. While there are gaps in our knowledge, especially in natural plant–rust systems, this review of the exposure of rust fungi to global change parameters revealed that some host–rust relationships would decline under predicted environmental change scenarios, whereas others would either remain unchanged or become more prevalent. Notably, some graminicolous rusts are negatively affected by higher temperatures and increased concentrations of atmospheric CO2. An increase of atmospheric O3 appears to favour rust diseases on trees but not those on grasses. Combined effects of CO2 and O3 are intermediary. The most important global drivers for the geographical and host plant range expansion and prevalence of rusts, however, are global plant trade, host plant genetic homogenization and the regular occurrence of conducive environmental conditions, especially the availability of moisture. However, while rusts thrive in high-humidity environments, they can also survive in desert habitats, and as a group their environmental tolerance is large, with no conclusive change in their overall prevalence predictable to date.

  20. Optimal alarm system applied in coffee rust

    Directory of Open Access Journals (Sweden)

    Luciene Resende Gonçalves

    2014-02-01

    Full Text Available Alarm systems have very great utility in detecting and warning of catastrophes. This methodology was applied via TARSO model with Bayesian estimation, serving as a forecasting mechanism for coffee rust disease. The coffee culture is very susceptible to this disease causing several records of incidence in most cultivated crops. Researches involving this limiting factor for production are intense and frequent, indicating environmental factors as responsible for the epidemics spread, which does not occur if these factors are not favorable. The fitting type used by the a posteriori probability, allows the system to be updated each time point. The methodology was applied to the rust index series in the presence of the average temperature series. Thus, it is possible to verify the alarm resulted or in a high catastrophe detection in points at which the catastrophe has not occurred, or in the low detections if the point was already in the catastrophe state.

  1. POPULATION GENETICS OF THE WHEAT LEAF RUST FUNGUS, PUCCINIA TRITICINA IN CENTRAL ASIA

    Science.gov (United States)

    Wheat leaf rust, caused by Puccinia triticina, is a major disease of wheat in Central Asia. Single uredinial isolates from Armenia, Azerbaijan, Tajikistan, Kazakhstan, Uzbekistan, and Kyrgyzstan, 131 in total, were tested for virulence to 20 isolines of Thatcher wheat with single leaf rust resistan...

  2. Duplications and losses in gene families of rust pathogens highlight putative effectors

    Directory of Open Access Journals (Sweden)

    Amanda L. Pendleton

    2014-06-01

    Full Text Available Rust fungi are a group of fungal pathogens that cause some of the world’s most destructive diseases of trees and crops. A shared characteristic among rust fungi is obligate biotrophy, the inability to complete a lifecycle without a host. This dependence on a host species likely affects patterns of gene expansion, contraction, and innovation within rust pathogen genomes. The establishment of disease by biotrophic pathogens is reliant upon effector proteins that are encoded in the fungal genome and secreted from the pathogen into the host’s cell apoplast or within the cells. This study uses a comparative genomic approach to elucidate putative effectors and determine their evolutionary histories. We used OrthoMCL to identify nearly 20,000 gene families in proteomes of sixteen diverse fungal species, which include fifteen basidiomycetes and one ascomycete. We inferred patterns of duplication and loss for each gene family and identified families with distinctive patterns of expansion/contraction associated with the evolution of rust fungal genomes. To recognize potential contributors for the unique features of rust pathogens, we identified families harboring secreted proteins that: i arose or expanded in rust pathogens relative to other fungi, or ii contracted or were lost in rust fungal genomes. While the origin of rust fungi appears to be associated with considerable gene loss, there are many gene duplications associated with each sampled rust fungal genome. We also highlight two putative effector gene families that have expanded in Cqf that we hypothesize have roles in pathogenicity.

  3. La Roya naranja de la caña de azúcar, una enfermedad emergente: su impacto y comparación con la roya marrón English Translation: Orange rust of sugarcane, an emerging disease: its impact and comparison to brown rust.

    Science.gov (United States)

    Sugarcane orange rust, caused by Puccinia kuehnii, was first detected in Florida in 2007, the first for Western Hemisphere. Subsequently, it has spread to the majority of sugarcane producing countries in the hemisphere. Orange rust is distinguished from brown rust its pustule size which is slightl...

  4. Effector proteins of rust fungi

    OpenAIRE

    Ben ePetre; Joly, David L.; Sébastien eDuplessis

    2014-01-01

    Rust fungi include many species that are devastating crop pathogens. To develop resistant plants, a better understanding of rust virulence factors, or effector proteins, is needed. Thus far, only six rust effector proteins have been described: AvrP123, AvrP4, AvrL567, AvrM, RTP1 and PGTAUSPE-10-1. Although some are well established model proteins used to investigate mechanisms of immune receptor activation (avirulence activities) or entry into plant cells, how they work inside host tissues to...

  5. Effector proteins of rust fungi

    OpenAIRE

    Petre, Benjamin; Joly, David L.; Duplessis, Sébastien

    2014-01-01

    Rust fungi include many species that are devastating crop pathogens. To develop resistant plants, a better understanding of rust virulence factors, or effector proteins, is needed. Thus far, only six rust effector proteins have been described: AvrP123, AvrP4, AvrL567, AvrM, RTP1, and PGTAUSPE-10-1. Although some are well established model proteins used to investigate mechanisms of immune receptor activation (avirulence activities) or entry into plant cells, how they work inside host tissues t...

  6. Tamper resistant magnetic stripes

    Science.gov (United States)

    Naylor, Richard Brian; Sharp, Donald J.

    1999-01-01

    This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180.degree. opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40.degree. C., is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable time limits.

  7. Screening for Sugarcane Brown Rust in the First Clonal Stage of the Canal Point Sugarcane Breeding Program

    OpenAIRE

    Duli Zhao; R. Wayne Davidson; Miguel Baltazar; Comstock, Jack C.; Per McCord; Sushma Sood

    2015-01-01

    Sugarcane (Saccharum spp.) brown rust (caused by Puccinia melanocephala Syd. & P. Syd.) was first reported in the United States in 1978 and is still one of the great challenges for sugarcane production. A better understanding of sugarcane genotypic variation in response to brown rust will help optimize breeding and selection strategies for disease resistance. Brown rust ratings were scaled from non-infection (0) to severe infection (4) with intervals of 0.5 and routinely recorded for geno...

  8. Spin stripes in nanotubes

    OpenAIRE

    Kleiner, Alex

    2002-01-01

    It is shown here that electrons on the surface of a nanotube in a perpendicular magnetic field undergo spin-chirality separation along the circumference. Stripes of spin-polarization propagate along the tube, with a spatial pattern that can be modulated by the electron filling.

  9. Barberry rust survey – developing tools for diagnosis, analysis and data management

    DEFF Research Database (Denmark)

    Justesen, Annemarie Fejer; Hansen, Jens Grønbech; Hovmøller, Mogens Støvring;

    Barberry (Berberis spp.) may serve as alternate host of several Puccinia species including Puccinia graminis and P. striiformis causing stem and yellow rust on cereals and grasses, respectively. In order to study the importance of barberry in the epidemiology of Puccinia species in the CWANA regi...... a rust survey was initiated. The aim was to 1) develop a surveillance protocol 2) develop molecular diagnostic tools for identifying Puccinia spp. from aecial samples, and 3) develop a data management and display system of results as part of the Wheat Rust ToolBox (http....... arrhenatheri and P. striiformoides on barberry species. Survey and DNA sample maps with species designation were displayed in the Wheat Rust ToolBox. The future aim is to integrate barberry rust survey data based on molecular diagnostics and infection assays from research groups world-wide in order to gain...

  10. Infection of Brachypodium distachyon with selected grass rust pathogens.

    Science.gov (United States)

    Ayliffe, Michael; Singh, Davinder; Park, Robert; Moscou, Matthew; Pryor, Tony

    2013-08-01

    The model temperate grass Brachypodium distachyon is considered a nonhost for wheat rust diseases caused by Puccinia graminis f. sp. tritici, P. triticina, and P. striiformis. Up to 140 Brachypodium accessions were infected with these three rust species, in addition to P. graminis ff. spp. avena and phalaridis. Related B. distachyon lines showed similar cytological nonhost resistance (NHR) phenotypes, and an inverse relationship between P. graminis f. sp. tritici and P. striiformis growth was observed in many lines, with accessions that allowed the most growth of P. graminis f. sp. tritici showing the least P. striiformis development and vice versa. Callose deposition patterns during infection by all three rust species showed similarity to the wheat basal defense response while cell death that resulted in autofluorescence did not appear to be a major component of the defense response. Infection of B. distachyon with P. graminis f. sp. avena and P. graminis f. sp. phalaridis produced much greater colonization, indicating that P. graminis rusts with Poeae hosts show greater ability to infect B. distachyon than those with Triticeae hosts. P. striiformis infection of progeny from two B. distachyon families demonstrated that these NHR phenotypes are highly heritable and appear to be under relatively simple genetic control, making this species a powerful tool for elucidating the molecular basis of NHR to cereal rust pathogens.

  11. Unveiling common responses of Medicago truncatula to appropriate and inappropriate rust species

    Directory of Open Access Journals (Sweden)

    Maria Carlota eVaz Patto

    2014-11-01

    Full Text Available Little is known about the nature of effective defense mechanisms in legumes to pathogens of remotely related plant species. Some rust species are among pathogens with broad host range causing dramatic losses in various crop plants. To understand and compare the different host and nonhost resistance responses of legume species against rusts, we characterized the reaction of the model legume Medicago truncatula to one appropriate (Uromyces striatus and two inappropriate (U. viciae-fabae and U. lupinicolus rusts. We found that similar pre and post-haustorial mechanisms of resistance appear to be operative in M. truncatula against appropriate and inappropriate rust fungus. The appropriate U. striatus germinated better on M. truncatula accessions then the inappropriate U. viciae-fabae and U. lupinicolus, but once germinated, germ tubes of the three rusts had a similar level of success in finding stomata and forming an appressoria over a stoma. However responses to different inappropriate rust species also showed some specificity, suggesting a combination of non specific and specific responses underlying this legume nonhost resistance to rust fungi. Further genetic and expression analysis studies will contribute to the development of the necessary molecular tools to use the present information on host and nonhost resistance mechanisms to breed for broad-spectrum resistance to rust in legume species.

  12. An analysis of the risk of introduction of additional strains of the rust puccinia psidii Winter ('Ohi'a Rust) to Hawai'i

    Science.gov (United States)

    Loope, Lloyd; La Rosa, Anne Marie

    2010-01-01

    In April 2005, the rust fungus Puccinia psidii (most widely known as guava rust or eucalyptus rust) was found in Hawai'i. This was the first time this rust had been found outside the Neotropics (broadly-defined, including subtropical Florida, where the rust first established in the 1970s). First detected on a nursery-grown 'ohi'a plant, it became known as ''ohi'a rust'in Hawai'i. The rust spread rapidly and by August 2005 had been found throughout the main Hawaiian Islands. The rust probably reached Hawai'i via the live plant trade or via the foliage trade. In Hawai'i, the rust has infected three native plant species and at least eight non-native species. Effects have been substantial on the endangered endemic plant Eugenia koolauensis and the introduced rose apple, Syzygium jambos. Billions of yellow, asexual urediniospores are produced on rose apple, but a complete life cycle (involving sexual reproduction) has not yet been observed. The rust is autoecious (no alternate host known) on Myrtaceae. The strain introduced into Hawai'i is found sparingly on 'ohi'a (Metrosideros polymorpha), the dominant tree of Hawai'i's forests, with sporadic damage detected to date. The introduction of a rust strain that causes widespread damage to 'ohi'a would be catastrophic for Hawai'i's native biodiversity. Most imports of material potentially contaminated with rust are shipped to Hawai'i from Florida and California (from which P. psidii was reported in late 2005 by Mellano, 2006). Florida is known to have multiple strains. The identity of the strain or strains in California is unclear, but one of them is known to infect myrtle, Myrtus communis, a species commonly imported into Hawai'i. It is important to ecosystem conservation and commercial forestry that additional rust strains or genotypes be prevented from establishing in Hawai'i. The purpose of this analysis of risk is to evaluate the need for an interim rule by the Hawai'i Department of Agriculture to regulate plant

  13. Suomi NPP VIIRS Striping Analysis using Radiative Transfer Model Calculations

    Science.gov (United States)

    Wang, Z.; Cao, C.

    2015-12-01

    Modern satellite radiometers such as VIIRS have many detectors with slightly different relative spectral response (RSR). These differences can introduce artifacts such as striping in the imagery. In recent studies we have analyzed the striping pattern related to the detector level RSR difference in VIIRS Thermal Emissive Bands (TEB) M15 and M16, which includes line-by-line radiative transfer model (LBLRTM) detector level response study and onboard detector stability evaluation using the solar diffuser. Now we extend these analysis to the Reflective Solar Bands (RSB) using MODTRAN atmospheric radiative transfer model (RTM) for detector level radiance simulation. Previous studies analyzed the striping pattern in the images of VIIRS ocean color and reflectance in RSB, further studies about the root cause for striping are still needed. In this study, we will use the MODTRAN model at spectral resolution of 1 cm^-1 under different atmospheric conditions for VIIRS RSB, for example band M1 centered at 410nm which is used for Ocean Color product retrieval. The impact of detector level RSR difference, atmospheric dependency, and solar geometry on the striping in VIIRS SDR imagery will be investigated. The cumulative histogram method used successfully for the TEB striping analysis will be used to quantify the striping. These analysis help S-NPP and J1 to better understand the root cause for VIIRS image artifacts and reduce the uncertainties in geophysical retrievals to meet the user needs.

  14. Photon energy absorption rate of a striped Hall gas

    OpenAIRE

    Ishizuka, Y.; Aoyama, T.; Maeda, N.; Ishikawa, K

    2004-01-01

    Using symmetries of the current correlation function, we analyze the frequency dependence of the photon energy absorption rate of a striped Hall gas. Since the magnetic translational symmetry is spontaneously broken in the striped Hall gas, a Nambu-Goldstone (NG) mode appears. It is shown that the NG mode causes a sharp absorption at the zero energy in the long wavelength limit by using the single mode approximation. The photon energy absorption rate at the NG mode frequency strongly depends ...

  15. Characteristics of superior soybean breeding lines tolerance to rust (Phakopsora pachyrhizi Syd.

    Directory of Open Access Journals (Sweden)

    Alfi Inayati

    2016-04-01

    Full Text Available Soybean rust caused by Phakopsora pachyrhizi is one of the most important diseases which limits soybean production. The aim of this study was to evaluate the resistance of 28 superior soybean lines and their tolerance to rust. The study was conducted at a screen house and arranged in a completely randomized design (CRD; three replications. All genotypes tested were artificially inoculated with P. pachyrhizi, and a set of un-inoculated genotypes was planted as a comparison. Number of pustules was recorded weekly, and resistant criteria was rated based on the International working group on soybean rust IWGSR method. Lesion color (LC, sporulation level (SL, number of uredia (NoU, frequency of pustule which had uredia, and yield were also recorded. Among 28 genotypes tested, only one was categorized as resistant and 2 genotypes were susceptible. Resistant genotypes had few pustules, lower AUDPC values, low disease severity, and Reddish Brown lesion type. Soybean rust affected yield components, i.e. number of intact pods and yield per plant. Yield loses due to rust in this study varied from 5-89%, and the average was 51%. The set of lines from Tanggamus pedigree showed more resistant to rust but less tolerant compared to Sinabung pedigree.How to CiteInayati, A., & Yusnawan, E. (2016. Characteristics of superior soybean breeding lines tolerancet to rust (Phakopsora pachyrhizi Syd.. Biosaintifika: Journal of Biology & Biology Education, 8(1, 47-55.

  16. Archaeophytopathology of Global Soybean Rust

    Science.gov (United States)

    Phakopsora pachyrhizi and P. meibomiae are two rust species that infect soybean (Glycine max). A number of other hosts support the uredinial growth of these Phakopsora, including Pachyrhizus erosus, Pueraria lobata, and Vigna unguiculata, but no aecial host is known. Traditionally, these two species...

  17. LMFBR thermal-striping evaluation

    International Nuclear Information System (INIS)

    Thermal striping is defined as the fluctuating temperature field that is imposed on a structure when fluid streams at different temperatures mix in the vicinity of the structure surface. Because of the uncertainty in structural damage in LMFBR structures subject to thermal striping, EPRI has funded an effort for the Rockwell International Energy Systems Group to evaluate this problem. This interim report presents the following information: (1) a Thermal Striping Program Plan which identifies areas of analytic and experimental needs and presents a program of specific tasks to define damage experienced by ordinary materials of construction and to evaluate conservatism in the existing approach; (2) a description of the Thermal Striping Test Facility and its operation; and (3) results from the preliminary phase of testing to characterize the fluid environment to be applied in subsequent thermal striping damage experiments

  18. Molecular mapping and improvement of leaf rust resistance in wheat breeding lines.

    Science.gov (United States)

    Tsilo, Toi J; Kolmer, James A; Anderson, James A

    2014-08-01

    Leaf rust, caused by Puccinia triticina, is the most common and widespread disease of wheat (Triticum aestivum) worldwide. Deployment of host-plant resistance is one of the strategies to reduce losses due to leaf rust disease. The objective of this study was to map genes for adult-plant resistance to leaf rust in a recombinant inbred line (RIL) population originating from MN98550-5/MN99394-1. The mapping population of 139 RILs and five checks were evaluated in 2005, 2009, and 2010 in five environments. Natural infection occurred in the 2005 trials and trials in 2009 and 2010 were inoculated with leaf rust. Four quantitative trait loci (QTL) on chromosomes 2BS, 2DS, 7AL, and 7DS were detected. The QTL on 2BS explained up to 33.6% of the phenotypic variation in leaf rust response, whereas the QTL on 2DS, 7AL, and 7DS explained up to 15.7, 8.1, and 34.2%, respectively. Seedling infection type tests conducted with P. triticina races BBBD and SBDG confirmed that the QTL on 2BS and 2DS were Lr16 and Lr2a, respectively, and these genes were expressed in the seedling and field plot tests. The Lr2a gene mapped at the same location as Sr6. The QTL on 7DS was Lr34. The QTL on 7AL is a new QTL for leaf rust resistance. The joint effects of all four QTL explained 74% of the total phenotypic variation in leaf rust severity. Analysis of different combinations of QTL showed that the RILs containing all four or three of the QTL had the lowest average leaf rust severity in all five environments. Deployment of these QTL in combination or with other effective genes will lead to successful control of leaf rust.

  19. Nonhost resistance of rice to rust pathogens.

    Science.gov (United States)

    Ayliffe, Michael; Devilla, Rosangela; Mago, Rohit; White, Rosemary; Talbot, Mark; Pryor, Anthony; Leung, Hei

    2011-10-01

    Rice is atypical in that it is an agricultural cereal that is immune to fungal rust diseases. This report demonstrates that several cereal rust species (Puccinia graminis f. sp tritici, P. triticina, P. striiformis, and P. hordei) can infect rice and produce all the infection structures necessary for plant colonization, including specialized feeding cells (haustoria). Some rust infection sites are remarkably large and many plant cells are colonized, suggesting that nutrient uptake occurs to support this growth. Rice responds with an active, nonhost resistance (NHR) response that prevents fungal sporulation and that involves callose deposition, production of reactive oxygen species, and, occasionally, cell death. Genetic variation for the efficacy of NHR to wheat stem rust and wheat leaf rust was observed. Unlike cereal rusts, the rust pathogen (Melampsora lini) of the dicotyledenous plant flax (Linum usitatissimum) rarely successfully infects rice due to an apparent inability to recognize host-derived signals. Morphologically abnormal infection structures are produced and appressorial-like structures often don't coincide with stomata. These data suggest that basic compatibility is an important determinate of nonhost infection outcomes of rust diseases on cereals, with cereal rusts being more capable of infecting a cereal nonhost species compared with rust species that are adapted for dicot hosts.

  20. Assessing the variability of Red Stripe Disease in Louisiana sugarcane using precision agriculture methods

    Science.gov (United States)

    Symptoms of red stripe disease caused by Acidovorax avenae subsp. avenae in Louisiana between 1985 and 2010 were limited to the leaf stripe form which caused no apparent yield loss. During 2010, the more severe top rot form was observed, and a study was initiated to investigate the distribution of r...

  1. Heritable, de novo resistance to leaf rust and other novel traits in selfed descendants of wheat responding to inoculation with wheat streak mosaic virus.

    Science.gov (United States)

    Seifers, Dallas L; Haber, Steve; Martin, Terry J; McCallum, Brent D

    2014-01-01

    Stable resistance to infection with Wheat streak mosaic virus (WSMV) can be evolved de novo in selfing bread wheat lines subjected to cycles of WSMV inoculation and selection of best-performing plants or tillers. To learn whether this phenomenon might be applied to evolve resistance de novo to pathogens unrelated to WSMV, we examined the responses to leaf rust of succeeding generations of the rust- and WSMV-susceptible cultivar 'Lakin' following WSMV inoculation and derived rust-resistant sublines. After three cycles of the iterative protocol five plants, in contrast to all others, expressed resistance to leaf and stripe rust. A subset of descendant sublines of one of these, 'R1', heritably and uniformly expressed the new trait of resistance to leaf rust. Such sublines, into which no genes from a known source of resistance had been introgressed, conferred resistance to progeny of crosses with susceptible parents. The F1 populations produced from crosses between, respectively, susceptible and resistant 'Lakin' sublines 4-3-3 and 4-12-3 were not all uniform in their response to seedling inoculation with race TDBG. In seedling tests against TDBG and MKPS races the F2s from F1 populations that were uniformly resistant had 3∶1 ratios of resistant to susceptible individuals but the F2s from susceptible F1 progenitors were uniformly susceptible. True-breeding lines derived from resistant individuals in F2 populations were resistant to natural stripe and leaf rust inoculum in the field, while the 'Lakin' progenitor was susceptible. The next generation of six of the 'Lakin'-derived lines exhibited moderate to strong de novo resistance to stem rust races TPMK, QFCS and RKQQ in seedling tests while the 'Lakin' progenitor was susceptible. These apparently epigenetic effects in response to virus infection may help researchers fashion a new tool that expands the range of genetic resources already available in adapted germplasm.

  2. Heritable, de novo resistance to leaf rust and other novel traits in selfed descendants of wheat responding to inoculation with wheat streak mosaic virus.

    Directory of Open Access Journals (Sweden)

    Dallas L Seifers

    Full Text Available Stable resistance to infection with Wheat streak mosaic virus (WSMV can be evolved de novo in selfing bread wheat lines subjected to cycles of WSMV inoculation and selection of best-performing plants or tillers. To learn whether this phenomenon might be applied to evolve resistance de novo to pathogens unrelated to WSMV, we examined the responses to leaf rust of succeeding generations of the rust- and WSMV-susceptible cultivar 'Lakin' following WSMV inoculation and derived rust-resistant sublines. After three cycles of the iterative protocol five plants, in contrast to all others, expressed resistance to leaf and stripe rust. A subset of descendant sublines of one of these, 'R1', heritably and uniformly expressed the new trait of resistance to leaf rust. Such sublines, into which no genes from a known source of resistance had been introgressed, conferred resistance to progeny of crosses with susceptible parents. The F1 populations produced from crosses between, respectively, susceptible and resistant 'Lakin' sublines 4-3-3 and 4-12-3 were not all uniform in their response to seedling inoculation with race TDBG. In seedling tests against TDBG and MKPS races the F2s from F1 populations that were uniformly resistant had 3∶1 ratios of resistant to susceptible individuals but the F2s from susceptible F1 progenitors were uniformly susceptible. True-breeding lines derived from resistant individuals in F2 populations were resistant to natural stripe and leaf rust inoculum in the field, while the 'Lakin' progenitor was susceptible. The next generation of six of the 'Lakin'-derived lines exhibited moderate to strong de novo resistance to stem rust races TPMK, QFCS and RKQQ in seedling tests while the 'Lakin' progenitor was susceptible. These apparently epigenetic effects in response to virus infection may help researchers fashion a new tool that expands the range of genetic resources already available in adapted germplasm.

  3. STRIPE: Remote Driving Using Limited Image Data

    Science.gov (United States)

    Kay, Jennifer S.

    1997-01-01

    Driving a vehicle, either directly or remotely, is an inherently visual task. When heavy fog limits visibility, we reduce our car's speed to a slow crawl, even along very familiar roads. In teleoperation systems, an operator's view is limited to images provided by one or more cameras mounted on the remote vehicle. Traditional methods of vehicle teleoperation require that a real time stream of images is transmitted from the vehicle camera to the operator control station, and the operator steers the vehicle accordingly. For this type of teleoperation, the transmission link between the vehicle and operator workstation must be very high bandwidth (because of the high volume of images required) and very low latency (because delayed images can cause operators to steer incorrectly). In many situations, such a high-bandwidth, low-latency communication link is unavailable or even technically impossible to provide. Supervised TeleRobotics using Incremental Polyhedral Earth geometry, or STRIPE, is a teleoperation system for a robot vehicle that allows a human operator to accurately control the remote vehicle across very low bandwidth communication links, and communication links with large delays. In STRIPE, a single image from a camera mounted on the vehicle is transmitted to the operator workstation. The operator uses a mouse to pick a series of 'waypoints' in the image that define a path that the vehicle should follow. These 2D waypoints are then transmitted back to the vehicle, where they are used to compute the appropriate steering commands while the next image is being transmitted. STRIPE requires no advance knowledge of the terrain to be traversed, and can be used by novice operators with only minimal training. STRIPE is a unique combination of computer and human control. The computer must determine the 3D world path designated by the 2D waypoints and then accurately control the vehicle over rugged terrain. The human issues involve accurate path selection, and the

  4. Progress Towards Genetics and Breeding for Minor Genes Based Resistance to Ug99 and Other Rusts in CIMMYT High-Yielding Spring Wheat

    Institute of Scientific and Technical Information of China (English)

    Ravi Prakash Singh; Sybil Herrera-Foessel; Julio Huerta-Espino; Sukhwinder Singh; Sridhar Bhavani; Caixia Lan; and Bhoja Raj Basnet

    2014-01-01

    Wheat rusts continue to cause signiifcant losses worldwide despite major efforts given to their genetic control. This is due to frequent evolution and selection of virulence in pathogen overcoming the deployed race-speciifc resistance genes. Although the life of effective race-speciifc resistance genes can be prolonged by using gene combinations, an alternative approach being implemented at CIMMYT is to deploy varieties that posses adult plant resistance (APR) based on combinations of minor, slow rusting genes. When present alone, the APR genes do not confer adequate resistance especially under high disease pressure; however, combinations of 4 or 5 minor genes usually result in “near-immunity” or a high level of resistance. Although only a few APR genes are catalogued, various APR QTLs are now known and could lead to further characterization of additional genes. Four characterized genes have pleiotropic effects in conferring partial APR to all 3 rusts and powdery mildew, thus simplifying the task of breeding wheat varieties that are resistant to multiple diseases. Signiifcant progress was made recently in developing high-yielding wheat germplasm that possesses high levels of APR to all three rusts by implementing a Mexico-Kenya shuttle breeding scheme. Parents with APR to Ug99 were hybridized with high-yielding parents that had adequate to high levels of APR to leaf rust and yellow rust. Segregating populations and advanced lines from these crosses were selected under high rust pressures in Mexico (leaf rust and yellow rust) and Kenya (Ug99 stem rust and yellow rust) to identify high-yielding progenies that possess high to adequate APR to all three rusts. International distribution of these high-yielding wheats is underway through CIMMYT international yield trials and screening nurseries. It is expected that several wheat varieties with APR to three rusts will be released and grown in various countries in the near-future that will allow determining the

  5. Abnormal relationship between rust particles size and rust layer compactness of weathering steels

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to reveal evolution of the rust layer during atmospheric corrosion,commercial weathering steel(WS) 09CuPCrNi and a recently developed bainite WS were subjected to a salt fog test.The protection and compactness of the rust layer were evaluated by electrochemical analysis,absorption-desorption test,etc.The experimental results indicate that more compact rust layer could be derived from the rust particles with larger size.The well-established notion that the rust particle growth can induce the decreme...

  6. Relationship of Soil Properties and Sugarcane Yields to Red Stripe in Louisiana.

    Science.gov (United States)

    Johnson, Richard M; Grisham, Michael P; Warnke, Kathryn Z; Maggio, Jeri R

    2016-07-01

    Symptoms of red stripe disease caused by Acidovorax avenae subsp. avenae in Louisiana between 1985 and 2010 were limited to the leaf stripe form, which caused no apparent yield loss. During 2010, the more severe top rot form was observed, and a study was initiated to investigate the distribution of red stripe in the field and determine its effects on cane and sugar yields. Soil properties data, red stripe incidence, and sugarcane yields were all highly variable and were not randomly distributed in the field. Combined harvest data showed a negative correlation between yield components and red stripe incidence, with the strongest relationship between sucrose per metric ton and disease incidence. Red stripe incidence was positively correlated with several soil properties, including phosphorus, potassium, zinc, and calcium. Red stripe incidence also was found to increase with increasing nitrogen rate, with the greatest effects in heavy soils. Results also indicated that using red-stripe-infected cane as a seed source can significantly decrease shoot emergence, stalk population, and subsequent cane and sugar yields. These combined data suggest that red stripe disease can exhibit a highly variable rate of infection in commercial sugarcane fields and may also significantly decrease sugar yields. PMID:27003508

  7. Sexual structures and recombination of the wheat rust fungus Puccinia striiformis on Berberis vulgaris.

    Science.gov (United States)

    Rodriguez-Algaba, Julian; Walter, Stephanie; Sørensen, Chris K; Hovmøller, Mogens S; Justesen, Annemarie F

    2014-09-01

    An isolate of the basidiomycete Puccinia striiformis, which causes yellow (stripe) rust on wheat, was selfed on the newly discovered alternate host, Berberis vulgaris. This allowed a study of the segregation of molecular markers and virulence in the progeny isolates, and of the development of fungal sexual structures and spore forms. Pycnia and aecia were obtained after inoculation of B. vulgaris with basidiospores resulting from germinating teliospores from infected wheat leaves. Subsequent inoculation of wheat with aeciospores from bulked aecia resulted in 16 progeny isolates of the S1 generation. Genotyping with 42 simple sequence repeat (SSR) markers confirmed a parental origin of progeny isolates. Of the 42 analyzed loci, 15 were heterozygous in the parental isolate and 14 revealed segregation in the progenies. This resulted in 11 new multilocus genotypes (MLGs), which confirmed segregation following sexual reproduction. Additionally, parental and progeny isolates were phenotyped using a genetic stock of wheat genotypes representing 21 resistance genes. All S1 progeny isolates had virulence for 14 out of 15 loci where the parental isolate was virulent. This was consistent with the hypothesis that virulence in plant pathogens is often recessive to avirulence, i.e., only expressed in a homozygous state. Furthermore, no segregation was observed for five out of six loci, for which the parental isolate had an avirulent phenotype. The results for one of the two segregating virulence/avirulence loci suggested that the parental isolate was heterozygous with Avr alleles resulting in different but clearly avirulent phenotypes. The other locus indicated that additional genes modifying the phenotypic expression of avirulence were involved. PMID:25042987

  8. Emerging Yr26-virulent races of Puccinia striiformis f. sp. tritici are threatening the wheat production in the Sichuan Basin, China

    Science.gov (United States)

    Stripe rust, caused by Puccinia striiformis f. sp. tritici , is one of the most destructive diseases of wheat in the world. The Sichuan Basin is one of the most important regions of wheat production and stripe rust epidemics in China. Stripe rust resistance gene Yr26 (the same gene as Yr24) has bee...

  9. Finite element simulation for damage detection of surface rust in steel rebars using elastic waves

    Science.gov (United States)

    Tang, Qixiang; Yu, Tzuyang

    2016-04-01

    Steel rebar corrosion reduces the integrity and service life of reinforced concrete (RC) structures and causes their gradual and sudden failures. Early stage detection of steel rebar corrosion can improve the efficiency of routine maintenance and prevent sudden failures from happening. In this paper, detecting the presence of surface rust in steel rebars is investigated by the finite element method (FEM) using surface-generated elastic waves. Simulated wave propagation mimics the sensing scheme of a fiber optic acoustic generator mounted on the surface of steel rebars. Formation of surface rust in steel rebars is modeled by changing material's property at local elements. In this paper, various locations of a fiber optic acoustic transducer and a receiver were considered. Megahertz elastic waves were used and different sizes of surface rust were applied. Transient responses of surface displacement and pressure were studied. It is found that surface rust is most detectable when the rust location is between the transducer and the receiver. Displacement response of intact steel rebar is needed in order to obtain background-subtracted response with a better signal-to-noise ratio. When the size of surface rust increases, reduced amplitude in displacement was obtained by the receiver.

  10. Screening oat populations for rust resistant mutants

    International Nuclear Information System (INIS)

    In 1972 a two million M2 plants were grown at Morden, Manitoba. Thirteen plants which were thought to have possible resistance to race CI0 of oat stem rust were harvested. After extensive seedling and adult plant rust tests the best of the selected plant progenies was crossed and backcrossed to Rodney 0, a stem rust susceptible oat. The resistance in this line M-72-6 was found to be controlled by a single gene. In 1973 another two million M2 plants were examined for rust resistance at Morden and 38 were harvested. None of the M2 plants selected in 1973 appeared to have any seedling or adult resistance when examined more thoroughly in the greenhouse and again in the field in 1974. In 1974 one million M2 plants were examined for resistance and 73 selected. None appeared to have any resistance when tested further. The strain CI3034 which was good adult plant stem rust resistance associated with weak straw and a light green plant colour was treated with gamma radiation and EMS in 1973 and the M2 grown in the C10 rust nursery at Morden in 1974. A considerable number of dark green plants were present in all treatments but unfortunately all were found to be stem rust susceptible. Thus it would appear to be difficult if not impossible to separate the rust resistance in CI3034 from the undesirable characters, weak straw and light green plant colour. (author)

  11. Development of a diagnostic co-dominant marker for stem rust resistance gene Sr47 introgressed from Aegilops speltoides into durum wheat

    Science.gov (United States)

    Stem rust (caused by Puccinia graminis f. sp. tritici, abbreviated as Pgt) resistance gene Sr47, originally transferred from Aegilops speltoides to durum wheat (Triticum turgidum subsp. durum) line DAS15, confers a high level of resistance to Pgt race TTKSK (known as Ug99). Recently, the durum Rust...

  12. Variation in chromosome constitution of the Xiaoyan series partial amphiploids and its relations to stripe rust and stem rust resistance

    Science.gov (United States)

    In the tertiary gene pool of wheat, tall wheatgrass Thinopyrum ponticum (2n = 10x = 70) is an excellent source of resistance genes against numerous wheat diseases. The creation of wheat-Th. ponticum partial amphiploids is an intermediate step for transferring the useful genes from Th. ponticum to w...

  13. Image processing methods for quantitatively detecting soybean rust from multispectral images

    Science.gov (United States)

    Soybean rust, caused by Phakopsora pachyrhizi, is one of the most destructive diseases for soybean production. It often causes significant yield loss and may rapidly spread from field to field through airborne urediniospores. In order to implement timely fungicide treatments for the most effective c...

  14. RAPD markers linked to a block of genes conferring rust resistance to the common bean

    Directory of Open Access Journals (Sweden)

    Faleiro Fábio Gelape

    2000-01-01

    Full Text Available Rust, caused by the fungus Uromyces appendiculatus, may cause a significant loss to common bean (Phaseolus vulgaris L. yield. RAPD markers tightly linked to the resistance genes may be used in breeding programs to aid the development of rust-resistant bean cultivars. In this sense, the objective of the present work was to identify RAPD markers linked to a rust resistance gene block present in the cultivar Ouro Negro. Two hundred and fourteen F2 individuals from a cross between the resistant cultivar Ouro Negro and the susceptible cultivar US Pinto 111 were inoculated with a mixture of eight races of U. appendiculatus. The segregation ratio obtained suggested that resistance is monogenic and dominant. Bulked segregant analysis was used in conjunction with the RAPD technique to search for markers linked to rust resistance genes. Two molecular markers flanking the rust resistance gene block were identified, one at 5.8 ± 1.6 cM (OX11(630 and the other at 7.7 ± 1.7 cM (OF10(1,050 of the gene. Simulated indirect selection efficiency in the F2 population using the two markers was 100%. The molecular markers identified in this work are currently being used for the selection of disease-resistant plants in the commom bean breeding program of the Federal University of Viçosa.

  15. Changing the game: using integrative genomics to probe virulence mechanisms of the stem rust pathogen Puccinia graminis f. sp. tritici

    OpenAIRE

    Melania eFigueroa; Narayana Mithur Upadhyaya; Jana eSperschneider; Robert ePark; Les eSzabo; Brian eSteffenson; Jeffrey eEllis; Peter eDodds

    2016-01-01

    The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt) poses a threat to food security. These concerns have catalyzed an extensive global effort towards controlling this disease. Substantial research and breeding programs target the identification and introduction of new stem rust resistance (Sr) genes in cultivars for genetic protection against the disease. Such resistance genes typically encode immune receptor proteins that recognize ...

  16. Changing the Game: Using Integrative Genomics to Probe Virulence Mechanisms of the Stem Rust Pathogen Puccinia graminis f. sp. tritici

    OpenAIRE

    Figueroa, Melania; Upadhyaya, Narayana M.; Sperschneider, Jana; Park, Robert F.; Szabo, Les J.; Steffenson, Brian; Ellis, Jeff G.; Dodds, Peter N.

    2016-01-01

    The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt) poses a threat to food security. These concerns have catalyzed an extensive global effort toward controlling this disease. Substantial research and breeding programs target the identification and introduction of new stem rust resistance (Sr) genes in cultivars for genetic protection against the disease. Such resistance genes typically encode immune receptor proteins that recognize s...

  17. The influence of canopy density on willow leaf rust (Melampsora epitea) severity in willow short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Toome, M.; Heinsoo, K.; Holm, B.; Luik, A. [Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1A, Tartu 51014 (Estonia)

    2010-08-15

    Willow short rotation coppice is used as a renewable energy source and also as a vegetation filter for purifying wastewater. Wastewater irrigation might change microclimatic conditions and increase the canopy density in plantations, which might decrease production due to leaf rust (Melampsora epitea). The aim of this study was to estimate the impact of the canopy density on rust abundance on willows. For that, we counted rust pustules on leaves of five different willow clones from dense and sparse areas in both the wastewater irrigated and control part of the plantation. The results demonstrated clear differences between clones; clone '81090' was very susceptible, '78183' susceptible, '78021' fairly tolerant and 'Tora' rust resistant. Clone 'Gudrun', which was previously reported resistant, had severe rust damages in Estonia. In the case of clones '78183' and '78021' there were significantly more rust pustules per leaf unit area at areas with denser canopy, which confirmed that higher plant density could result in biomass losses caused by leaf rust. No differences, however, were detected between dense and sparse areas of hybrid clone 'Gudrun', most probably because in this particular case leaves from upper canopy layer were used. There was a tendency detected that clones with a higher number of shoots per plant had more rust damages on their leaves, however, the correlation was not statistically confirmed. In conclusion, the impact of canopy density on rust abundance is clone-specific and significant in the case of clones on which infection starts from the lower part of the canopy. (author)

  18. Environmental quality for striped bass

    Energy Technology Data Exchange (ETDEWEB)

    Coutant, C. C.

    1980-01-01

    Effects of environmental changes on the quality of life for striped bass populations can be evaluated objectively with modern procedures of environmental risk analysis. Such analysis requires knowledge of the sources of risk in the context of environmental requirements of the species. A prime environmental requirement of striped bass appears to be a suitable thermal structure that accommodates the hereditary thermal niche, which changes with age. Strong thermal preferences had promoted striped bass survival in the pristine natural estuaries of eastern North America, but they may increase risks to the species in some new environments and in native ones that are altered by man. The magnitude and likelihood of risks for striped bass from many pollutants and physical changes (structures or water flow, for example) depend upon the fish's thermally controlled distribution. The importance of a species' thermal niche and of the thermal structure of aquatic environments for population success is only beginning to be recognized and included in risk assessments.

  19. Epidemiology of bean rust in Ethiopia.

    NARCIS (Netherlands)

    Habtu Assefa,

    1994-01-01

    Field and greenhouse experiments were conducted to study the epidemiology of rust ( Uromyces appendiculatus ) on beans ( Phaseolus vulgaris L.) in Ethiopia. The experiments were conducted under low input conditions reflecting the traditional bean production practices. Surveys identified five major

  20. Putative Rust Fungal Effector Proteins in Infected Bean and Soybean Leaves.

    Science.gov (United States)

    Cooper, Bret; Campbell, Kimberly B; Beard, Hunter S; Garrett, Wesley M; Islam, Nazrul

    2016-05-01

    The plant-pathogenic fungi Uromyces appendiculatus and Phakopsora pachyrhizi cause debilitating rust diseases on common bean and soybean. These rust fungi secrete effector proteins that allow them to infect plants, but their effector repertoires are not understood. The discovery of rust fungus effectors may eventually help guide decisions and actions that mitigate crop production loss. Therefore, we used mass spectrometry to identify thousands of proteins in infected beans and soybeans and in germinated fungal spores. The comparative analysis between the two helped differentiate a set of 24 U. appendiculatus proteins targeted for secretion that were specifically found in infected beans and a set of 34 U. appendiculatus proteins targeted for secretion that were found in germinated spores and infected beans. The proteins specific to infected beans included family 26 and family 76 glycoside hydrolases that may contribute to degrading plant cell walls. There were also several types of proteins with structural motifs that may aid in stabilizing the specialized fungal haustorium cell that interfaces the plant cell membrane during infection. There were 16 P. pachyrhizi proteins targeted for secretion that were found in infected soybeans, and many of these proteins resembled the U. appendiculatus proteins found in infected beans, which implies that these proteins are important to rust fungal pathology in general. This data set provides insight to the biochemical mechanisms that rust fungi use to overcome plant immune systems and to parasitize cells.

  1. Genetic analysis of seedling resistance to crown rust in five diploid oat (Avena strigosa) accessions.

    Science.gov (United States)

    Cabral, A L; Park, R F

    2016-02-01

    Crown rust, caused by Puccinia coronata Corda f. sp. avenae Eriks., is a serious menace in oats, for which resistance is an effective means of control. Wild diploid oat accessions are a source of novel resistances that first need to be characterised prior to introgression into locally adapted oat cultivars. A genetic analysis of resistance to crown rust was carried out in three diverse diploid oat accessions (CIav6956, CIav9020, PI292226) and two cultivars (Saia and Glabrota) of A. strigosa. A single major gene conditioning resistance to Australian crown rust pathotype (Pt) 0000-2 was identified in each of the three accessions. Allelism tests suggested that these genes are either the same, allelic, or tightly linked with less than 1 % recombination. Similarly, a single gene was identified in Glabrota, and possibly two genes in Saia; both cultivars previously reported to carry two and three crown rust resistance genes, respectively. The identified seedling resistance genes could be deployed in combination with other resistance gene(s) to enhance durability of resistance to crown rust in hexaploid oat. Current diploid and hexaploid linkage maps and molecular anchor markers (simple sequence repeat [SSR] and diversity array technology [DArT] markers) should facilitate their mapping and introgression into hexaploid oat.

  2. 76 FR 3011 - Black Stem Rust; Additions of Rust-Resistant Varieties

    Science.gov (United States)

    2011-01-19

    ... / Wednesday, January 19, 2011 / Rules and Regulations#0;#0; ] DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service 7 CFR Part 301 Black Stem Rust; Additions of Rust-Resistant Varieties AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Direct final rule; confirmation of...

  3. 75 FR 44881 - Black Stem Rust; Additions of Rust-Resistant Varieties

    Science.gov (United States)

    2010-07-30

    ... / Friday, July 30, 2010 / Rules and Regulations#0;#0; ] DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service 7 CFR Part 301 Black Stem Rust; Additions of Rust-Resistant Varieties AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Direct final rule; confirmation of effective...

  4. Tagging and mapping of SSR marker for rust resistance gene in lentil (Lens culinaris Medikus subsp. culinaris).

    Science.gov (United States)

    Dikshit, H K; Singh, Akanksha; Singh, D; Aski, M; Jain, Neelu; Hegde, V S; Basandrai, A K; Basandrai, D; Sharma, T R

    2016-06-01

    Lentil, as an economical source of protein, minerals and vitamins, plays important role in nutritional security of the common man. Grown mainly in West Asia, North Africa (WANA) region and South Asia, it suffers from several biotic stresses such as wilt, rust, blight and broomrape. Lentil rust caused by autoecious fungus Uromyces viciae fabae (Pers.) Schroet is a serious lentil disease in Algeria, Bangladesh, Ethiopia, India, Italy, Morocco, Pakistan and Nepal. The disease symptoms are observed during flowering and early podding stages. Rust causes severe yield losses in lentil. It can only be effectively controlled by identifying the resistant source, understanding its inheritance and breeding for host resistance. The obligate parasitic nature of pathogen makes it difficult to maintain the pathogen in culture and to apply it to screen segregating progenies under controlled growth conditions. Hence, the use of molecular markers will compliment in identification of resistant types in different breeding programs. Here, we studied the inheritance of resistance to rust in lentil using F₁, F₂ and F₂:₃ from cross PL 8 (susceptible) x L 4149 (resistant) varieties. The phenotyping of lentil population was carried out at Sirmour, India. The result of genetic analysis revealed that a single dominant gene controls rust resistance in lentil genotype L 4149. The F2 population from this cross was used to tag and map the rust resistance gene using SSR and SRAP markers. Markers such as 270 SRAP and 162 SSR were studied for polymorphism and 101 SRAP and 33 SSRs were found to be polymorphic between the parents. Two SRAP and two SSR markers differentiated the resistant and susceptible bulks. SSR marker Gllc 527 was estimated to be linked to rust resistant locus at a distance of 5.9 cM. The Gllc 527 marker can be used for marker assisted selection for rust resistance; however, additional markers closer to rust resistant locus are required. The markers linked to the rust

  5. Leaf rust resistance in wheat line RL6062 is an allele at the Lr3 locus

    Science.gov (United States)

    RL6062, a 'Thatcher' backcross line of wheat (Triticum aestivum L.) has resistance to leaf rust (caused by Puccinia triticina) derived from a line of common wheat from Iran. RL6062 has an intermediate infection type (IT) of small to moderate uredinia surrounded by distinct chlorosis. RL6062 was cros...

  6. Sources of stem rust resistance in wheat-alien introgression lines

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis f. sp. tritici, is one of the most devastating diseases of wheat and the novel highly virulent race of TTKSK and its lineage are threatening wheat production worldwide. The objective of the study was to identify new sources of resistance in wheat-alien introgre...

  7. First report of soybean rust (Phakopsora pachyrhizi) on Florida beggarweed (Desmodium tortuosum) in Alabama

    Science.gov (United States)

    Soybean rust, caused by the fungus Phakopsora pachyrhizi, was detected on Florida Beggarweed (Desmodium tortuosum) for the first time in Alabama in November, 2009. The pathogen was observed on plants collected from a field at the Wiregrass Research and Extension Center in Headland, Alabama located i...

  8. Genome Wide Association Analysis of Leaf Rust Response in a Worldwide Germplasm Collection of Durum Wheat

    Science.gov (United States)

    Leaf rust (caused by Puccinia triticina Eriks.) is increasingly impacting durum wheat production with the recent appearance of races with virulence to widely grown cultivars in many durum producing areas worldwide. A highly virulent P. triticina race on durum wheat was recently collected in Kansas....

  9. Molecular mapping of R11, a novel rust resistance gene in sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Sunflower production in North America has recently been threatened by the evolution of new virulent pathotypes of sunflower rust caused by the fungus Puccinia helianthi Schwein. Rf ANN-1742, an ‘HA 89’ backcross restorer line derived from wild annual sunflower (Helianthus annuus L), was identified a...

  10. URS Brava – a new oat cultivar with partial resistance to crown rust

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Federizzi

    2015-08-01

    Full Text Available The cultivar URS Brava, obtained from a simple cross between the line ‘UFRGS 995078-2’ and the cultivar ‘URS 21’, shows high grain yield and stability, high grain quality, desirable agronomical traits and partial resistance to crown rust, caused by the fungus Puccinia coronata f. sp. avenae.

  11. Orange rust: A new surgarcane disease in Florida

    Science.gov (United States)

    Orange rust of sugarcane was observed approximately 5 miles east of Belle Glade, Florida on CP 80-1743 (a complex hybrid of Sacharum L. species) during the lsat week of June 2007. Orange rust pustules are cinnamon-orange in color, oval and smaller than the darker brown elongate rust pustules of the ...

  12. Aspects of durable resistance in wheat to yellow rust.

    NARCIS (Netherlands)

    Danial, D.L.

    1994-01-01

    In Kenya, the number of virulence factors of the yellow rust populations showed a considerable increase and a wide variability. Selecting for complete to near complete resistance to yellow rust and other cereal rust diseases, was followed by a rapid erosion of resistance.Partial resistance in wheat

  13. Striped ratio grids for scatter estimation

    Science.gov (United States)

    Hsieh, Scott S.; Wang, Adam S.; Star-Lack, Josh

    2016-03-01

    Striped ratio grids are a new concept for scatter management in cone-beam CT. These grids are a modification of conventional anti-scatter grids and consist of stripes which alternate between high grid ratio and low grid ratio. Such a grid is related to existing hardware concepts for scatter estimation such as blocker-based methods or primary modulation, but rather than modulating the primary, the striped ratio grid modulates the scatter. The transitions between adjacent stripes can be used to estimate and subtract the remaining scatter. However, these transitions could be contaminated by variation in the primary radiation. We describe a simple nonlinear image processing algorithm to estimate scatter, and proceed to validate the striped ratio grid on experimental data of a pelvic phantom. The striped ratio grid is emulated by combining data from two scans with different grids. Preliminary results are encouraging and show a significant reduction of scatter artifact.

  14. Amino acid uptake in rust fungi.

    Science.gov (United States)

    Struck, Christine

    2015-01-01

    The plant pathogenic rust fungi colonize leaf tissue and feed off their host plants without killing them. Certain economically important species of different genera such as Melampsora, Phakopsora, Puccinia, or Uromyces are extensively studied for resolving the mechanisms of the obligate biotrophy. As obligate parasites rust fungi only can complete their life cycle on living hosts where they grow through the leaf tissue by developing an extended network of intercellular hyphae from which intracellular haustoria are differentiated. Haustoria are involved in key functions of the obligate biotrophic lifestyle: suppressing host defense responses and acquiring nutrients. This review provides a survey of rust fungi nitrogen nutrition with special emphasis on amino acid uptake. A variety of sequences of amino acid transporter genes of rust fungi have been published; however, transport activity of only three in planta highly up-regulated amino acid permeases have been characterized. Functional and immunohistochemical investigations have shown the specificity and localization of these transporters. Sequence data of various genome projects allowed identification of numerous rust amino acid transporter genes. An in silico analysis reveals that these genes can be classified into different transporter families. In addition, genetic and molecular data of amino acid transporters have provided new insights in the corresponding metabolic pathways.

  15. Genetic analysis and molecular mapping of crown rust resistance in common wheat.

    Science.gov (United States)

    Niu, Zhixia; Puri, Krishna D; Chao, Shiaoman; Jin, Yue; Sun, Yongliang; Steffenson, Brian J; Maan, Shivcharan S; Xu, Steven S; Zhong, Shaobin

    2014-03-01

    This is the first report on genetic analysis and genome mapping of major dominant genes for near non-host resistance to barley crown rust ( Puccinia coronata var. hordei ) in common wheat. Barley crown rust, caused by Puccinia coronata var. hordei, primarily occurs on barley (Hordeum vulgare L.) in the Great Plain regions of the United States. However, a few genotypes of common wheat (Triticum aestivum L.) were susceptible to this pathogen among 750 wheat accessions evaluated. To investigate the genetics of crown rust resistance in wheat, a susceptible winter wheat accession PI 350005 was used in crosses with two resistant wheat varieties, Chinese Spring and Chris. Analysis of F1 plants and F2 populations from these two crosses indicated that crown rust resistance is controlled by one and two dominant genes in Chris and Chinese Spring, respectively. To determine the chromosome location of the resistance gene Cr1 in Chris, a set of 21 monosomic lines derived from Chris was used as female parents to cross with a susceptible spring type selection (SSTS35) derived from the PI 350005/Chris cross. Monosomic analysis indicated that Cr1 is located on chromosome 5D in Chris and one of the crown rust resistance genes is located on chromosome 2D in Chinese Spring. The other gene in Chinese Spring is not on 5D and thus is different from Cr1. Molecular linkage analysis and QTL mapping using a population of 136 doubled haploid lines derived from Chris/PI 350005 further positioned Cr1 between SSR markers Xwmc41-2 and Xgdm63 located on the long arm of chromosome 5D. Our study suggests that near non-host resistance to crown rust in these different common wheat genotypes is simply inherited.

  16. Genetics and Mapping of Seedling Resistance to Ug99 Stem Rust in the Winter Wheat Cultivar Triumph 64 and Differentiation of SrTmp, SrCad, and Sr42

    Science.gov (United States)

    Stem rust, caused by the fungus Puccinia graminis f. sp. tritici Eriks. & E. Henn. (Pgt), is an important disease of wheat that can be controlled by deploying effective stem rust resistance (Sr) genes. The emergence of virulent Pgt races in Africa, namely Ug99 and its variants, has stimulated the se...

  17. Identification of Green Rust in Groundwater

    DEFF Research Database (Denmark)

    Christiansen, Bo C.; Balic Zunic, Tonci; Dideriksen, Knud;

    2009-01-01

    Green rust, a family of Fe(II),Fe(III) layered double hydroxides, is believed to be present in environments close to the Fe(II)/Fe(III) transition zone. Attempts to identify members of this family in nature have proven difficult because the material is oxidized after only a few minutes exposure...... to air. In this paper, we present a sampling method for capturing green rust so it is not oxidized. We then we used the method to identify the compound in a groundwater sample taken below the water table from fractures in granite. X-ray diffraction patterns were weak, but clearly identical to those...... of synthetic GRCO3, the green rust familymemberwherecarbonate and water occupy the interlayer between the iron-hydroxide layers. The method was then tested on samples taken from an artesian well and a deep underground experimental station, both within the Fe(II)/Fe(III) redox zone. In both cases, GRCO3 could...

  18. Finite Element Analysis Of Thermal Transients In Multi-Stripe Laser Diode Arrays

    Science.gov (United States)

    Lippincott, Wendy L.; Clement, Anne E.

    1989-05-01

    The NASTRAN finite element code was used to simulate the temperature transients in the active area of laser diode arrays caused by driving the array with a pulsed waveform. A ten-stripe multi-quantum-well (MQW) structure was used. The thermal impedance of the array was also determined and compared to experimental values obtained by monitoring the threshold dependance of the device during pulsed and cw operation. The single-stripe diode was also modeled for comparison purposes.

  19. The barley stem rust-resistance gene Rpg1 is a novel disease-resistance gene with homology to receptor kinases

    OpenAIRE

    Brueggeman, R.; Rostoks, N.; Kudrna, D.; Kilian, A.; Han, F.; Chen, J; Druka, A.; Steffenson, B.; Kleinhofs, A

    2002-01-01

    Stem rust caused by Puccinia graminis f. sp. tritici was among the most devastating diseases of barley in the northern Great Plains of the U.S. and Canada before the deployment of the stem rust-resistance gene Rpg1 in 1942. Since then, Rpg1 has provided durable protection against stem rust losses in widely grown barley cultivars (cvs.). Extensive efforts to clone Rpg1 by synteny with rice provided excellent flanking markers but failed to yield the gene because it does ...

  20. Comparison of multi- and hyperspectral imaging data of leaf rust infected wheat plants

    Science.gov (United States)

    Franke, Jonas; Menz, Gunter; Oerke, Erich-Christian; Rascher, Uwe

    2005-10-01

    In the context of precision agriculture, several recent studies have focused on detecting crop stress caused by pathogenic fungi. For this purpose, several sensor systems have been used to develop in-field-detection systems or to test possible applications of remote sensing. The objective of this research was to evaluate the potential of different sensor systems for multitemporal monitoring of leaf rust (puccinia recondita) infected wheat crops, with the aim of early detection of infected stands. A comparison between a hyperspectral (120 spectral bands) and a multispectral (3 spectral bands) imaging system shows the benefits and limitations of each approach. Reflectance data of leaf rust infected and fungicide treated control wheat stand boxes (1sqm each) were collected before and until 17 days after inoculation. Plants were grown under controlled conditions in the greenhouse and measurements were taken under consistent illumination conditions. The results of mixture tuned matched filtering analysis showed the suitability of hyperspectral data for early discrimination of leaf rust infected wheat crops due to their higher spectral sensitivity. Five days after inoculation leaf rust infected leaves were detected, although only slight visual symptoms appeared. A clear discrimination between infected and control stands was possible. Multispectral data showed a higher sensitivity to external factors like illumination conditions, causing poor classification accuracy. Nevertheless, if these factors could get under control, even multispectral data may serve a good indicator for infection severity.

  1. Zoete rust : een muzikale soap-detective

    NARCIS (Netherlands)

    Maas, P.

    1989-01-01

    De komedie' Zoete Rust' werd geschreven in opdracht van Theater de Tobbe in Voorburg . Naast de circa 120 professionele voorstellingen die elk seizoen in dit theater plaats vinden, organiseert De Tobbe een maal per laar een eigen theaterproduktie, die wordt gespeeld door het Tobbe-toneel, een ad-hoc

  2. Genetic Analysis and Molecular Tagging a Novel Yellow Rust Resistance Gene Derived from Synthetic Hexaploid Wheat Germplasm M08

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-yue; LI Li-hui

    2008-01-01

    Yellow rust of wheat(caused by Puccinia striiformis Westend.f sp.tritici Eriks.)has been periodically epidemic and severely damaged wheat production in China.The development of resistant cultivars could be an effective way to reduce yield losses of wheat caused by yellow rust.Rust reaction tests and genetic analysis indicated that M08,the synthetic hexaploid wheat derived from hybridization between Triticum durum(2n=6X=28;genome AABB)and Aegilops tauschii (2n=2X=14;genome DD),showed resistance to current prevailing yellow rust races at seedling stage,which was controlled by a single dominant gene,designated as YrAm.Bulked segregant analysis was used to identify microsatellite markers linked to gene YrAm in an F2 population derived from cross M08(resistant)×Jinan 17(susceptible).Three microsatellite marker loci Xgwm77,Xgwm285,and Xgwm131 located on chromosome 3B were mapped to the YrAm locus. Xgwm131 was the closest marker locus and showed a linkage distance of 7.8 cM to the resistance locus.Thus,it is assumed that YrAm for resistance to yellow rust may be derived from Triticum durum and is located on the long arm of chromosome 3B.

  3. Control of Asian soybean rust with mancozeb, a multi-site fungicide

    Directory of Open Access Journals (Sweden)

    Luís Henrique Carregal Pereira da Silva

    2015-03-01

    Full Text Available An experiment conducted in the field the action of mancozeb, a fungicide of multi-site action was tested, to control soybean rust caused by Phakopsora pachyrhizi. Its performance was compared to that of the mixture cyproconazole (DMI + azoxystrobin (QoI. The soybean cultivar NA 7337 RR was used with a population of 400,000 plants/ha cultivated in 20m2 plots. Treatments consisted of mancozeb levels (1.5 and 2.0 kg/ha applied four, six and eight times. The DMI + QoI mixture was applied three times at 0.3 L/ha + Nimbus. Rust severity was assessed six times in the plots and data were integrated as the area under the disease progress curve (AUDPC. The plots were harvested and grain yield was expressed as kg/ha. Data on AUDPC and yield were subjected to analysis of variance and means compared according to Turkey's test (p = 0.005. Treatments with mancozeb were superior to DMI + QoI mixture both for rust control and grain yield. Four applications of 2.0 k/ha mancozeb were more efficient than three applications of the mixture used as standard. Mancozeb has the potential to be added to fungicide mixtures in the establishment of soybean rust anti-resistance strategy.

  4. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in 'Thatcher' Wheat.

    Science.gov (United States)

    Hiebert, Colin W; Kolmer, James A; McCartney, Curt A; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N; Spielmeyer, Wolfgang

    2016-01-01

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. 'Thatcher' wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in 'Thatcher' and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for 'Thatcher'-derived APR in several environments and this resistance was enhanced in the presence of Lr34.

  5. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in 'Thatcher' Wheat.

    Directory of Open Access Journals (Sweden)

    Colin W Hiebert

    Full Text Available Stem rust, caused by Puccinia graminis (Pgt, is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. 'Thatcher' wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in 'Thatcher' and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for 'Thatcher'-derived APR in several environments and this resistance was enhanced in the presence of Lr34.

  6. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in ‘Thatcher’ Wheat

    Science.gov (United States)

    Hiebert, Colin W.; Kolmer, James A.; McCartney, Curt A.; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N.; Spielmeyer, Wolfgang

    2016-01-01

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. ‘Thatcher’ wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in ‘Thatcher’ and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for ‘Thatcher’-derived APR in several environments and this resistance was enhanced in the presence of Lr34. PMID:27309724

  7. Are stripes beneficial? Dazzle camouflage influences perceived speed and hit rates.

    Directory of Open Access Journals (Sweden)

    Bettina von Helversen

    Full Text Available In the animal kingdom, camouflage refers to patterns that help potential prey avoid detection. Mostly camouflage is thought of as helping prey blend in with their background. In contrast, disruptive or dazzle patterns protect moving targets and have been suggested as an evolutionary force in shaping the dorsal patterns of animals. Dazzle patterns, such as stripes and zigzags, are thought to reduce the probability with which moving prey will be captured by impairing predators' perception of speed. We investigated how different patterns of stripes (longitudinal-i.e., parallel to movement direction-and vertical-i.e., perpendicular to movement direction affect the probability with which humans can hit moving objects and if differences in hitting probability are caused by a misperception of speed. A first experiment showed that longitudinally striped objects were hit more often than unicolored objects. However, vertically striped objects did not differ from unicolored objects. A second study examining the link between perceived speed and hitting probability showed that longitudinally and vertically striped objects were both perceived as moving faster and were hit more often than unicolored objects. In sum, our results provide evidence that striped patterns disrupt the perception of speed, which in turn influences how often objects are hit. However, the magnitude and the direction of the effects depend on additional factors such as speed and the task setup.

  8. Are stripes beneficial? Dazzle camouflage influences perceived speed and hit rates.

    Science.gov (United States)

    von Helversen, Bettina; Schooler, Lael J; Czienskowski, Uwe

    2013-01-01

    In the animal kingdom, camouflage refers to patterns that help potential prey avoid detection. Mostly camouflage is thought of as helping prey blend in with their background. In contrast, disruptive or dazzle patterns protect moving targets and have been suggested as an evolutionary force in shaping the dorsal patterns of animals. Dazzle patterns, such as stripes and zigzags, are thought to reduce the probability with which moving prey will be captured by impairing predators' perception of speed. We investigated how different patterns of stripes (longitudinal-i.e., parallel to movement direction-and vertical-i.e., perpendicular to movement direction) affect the probability with which humans can hit moving objects and if differences in hitting probability are caused by a misperception of speed. A first experiment showed that longitudinally striped objects were hit more often than unicolored objects. However, vertically striped objects did not differ from unicolored objects. A second study examining the link between perceived speed and hitting probability showed that longitudinally and vertically striped objects were both perceived as moving faster and were hit more often than unicolored objects. In sum, our results provide evidence that striped patterns disrupt the perception of speed, which in turn influences how often objects are hit. However, the magnitude and the direction of the effects depend on additional factors such as speed and the task setup. PMID:23637795

  9. Efeito de fungicidas cúpricos, aplicados isoladamente ou em combinação com mancozeb, na expressão de sintomas de fitotoxicidade e controle da ferrugem causada por Puccinia psidii em goiabeira Effect of copper fungicides, sprayed alone or in combination with mancozeb, in expression of phytotoxicity symptoms and rust control caused by Puccinia psidii in guava

    Directory of Open Access Journals (Sweden)

    Antonio de Goes

    2004-08-01

    used in Experiment 1, plus a treatment with tebucunazole in order to evaluate the rust control. In Experiment 1 none of the fungicides tested caused phytotoxicity symptoms and abortion of fruits less than 15 mm in diameter. The fungicides caused higher phytotoxicity in fruits between 25 and 35 mm but not in fruits larger than 40 mm diameter. Copper fungicides combined with mancozeb lead to a slight toxicity, but when applied the mancozeb alone did not lead to phytotoxicity sympton. In The Experiment 2, it was observed that copper fungicides applied alone were efficient to control rust as well as the combination of mancozeb and cuprous oxide or hydroxide and the fungicide tebuconazole.

  10. Fine Mapping of RppP25, a Southern Rust Resistance Gene in Maize

    Institute of Scientific and Technical Information of China (English)

    Panfeng Zhao; Guobin Zhang; Xiaojun Wu; Na Li; Dianyi Shi; Dengfeng Zhang; Chunfang Ji

    2013-01-01

    Southern rust (Puccinia polysora Underw.) is a major disease that can cause severe yield losses in maize (Zea mays L.).In our previous study,a major gene RppP25 that confers resistance to southern rust was identified in inbred line P25.Here,we report the fine mapping and candidate gene analysis of RppP25from the near-isogenic line F939,which harbors RppP25 in the genetic background of the susceptible inbred line F349.The inheritance of resistance to southern rust was investigated in the BC1F1 and BC3F1 populations,which were derived from a cross between F939 and F349 (as the recurrent parent).The 1:1 segregation ratio of resistance to susceptible plants in these two populations indicated that the resistance is controlled by a single dominant gene.Ten markers,including three simple sequence repeat (SSR) markers and seven insertion/deletion (InDel) markers,were developed in the RppP25 region.RppP25 was delimited to an interval between P091 and M271,with an estimated length of 40 kb based on the physical map of B73.In this region,a candidate gene was identified that was predicted to encode a putative nucleotide-binding site leucine-rich repeat (NBS-LRR) protein.Two co-segregated markers will aid in pyramiding diverse southern rust resistance alleles into elite materials,and thereby improve southern rust resistance worldwide.

  11. Theoretical studies on the mechanisms of laser rust removal

    Science.gov (United States)

    Wang, Yupei; Zhang, Zunyue; Liu, Guigeng; Song, Feng

    2016-05-01

    Our studies introduce the three-layer model of laser rust removal by rotational mirror scanner and develop dry laser cleaning model Firstly, theoretically simulate the temperature field of the rotational mirror scanner. Use the superposition model of the instantaneous thermal source point from a point to a line, from a line to an area, to simulate the temperature field distribution of rust and iron with thermal source on its surface and how it varies with time. And then take the temperature field distribution of rotational mirror scanner as the thermal load and use ANSYS to solve the thermal conductivity equations with complicated boundary conditions, and calculate the temperature field distribution it can be found that the temperature of the rust surface reaches the melting even the boiling point of the rust, so the rust can be removed by the ablation effect. From the thermal stress distribution of rust and iron in the depth orientation, the thermal stress existed in the rust and iron is large enough to remove the last rust layer in one time. So ablation layer, thermal stress removal layer and substrate consist of the three-layer model of laser rust removal by rotational mirror scanner.

  12. Ultrafast charge localization in a stripe-phase nickelate

    Energy Technology Data Exchange (ETDEWEB)

    Coslovich, Giacomo; Huber, Bernhard; Lee, Wei-Sheng; Sasagawa, Takao; Hussain, Zahid; Bechtel, Hans A.; Martin, Michael C.; Shen, Zhi-Xun; W. Schoenlein, Robert; A. Kaindl, Robert

    2013-08-30

    Self-organized electronically-ordered phases are a recurring feature in correlated materials, resulting in e.g. fluctuating charge stripes whose role in high-Tc superconductivity is under debate. However, the relevant cause-effect relations between real-space charge correlations and low-energy excitations remain hidden in time-averaged studies. Here, we reveal ultrafast charge localization and lattice vibrational coupling as dynamical precursors of stripe formation in the model compound La1.75Sr0.25NiO4, using ultrafast and equilibrium mid-infrared spectroscopy. The opening of a pseudogap at a crossover temperature T* far above long-range stripe formation establishes the onset of electronic localization which is accompanied by an enhanced Fano asymmetry of Ni-O stretch vibrations. Ultrafast excitation triggers a sub-picosecond dynamics exposing the synchronous modulation of electron-phonon coupling and charge localization. These results illuminate the role of localization in forming the pseudogap in nickelates, opening a path to understanding this mysterious phase in a broad class of complex oxides.

  13. Study on Diversity of Rust Fungi in Ningxia%宁夏锈菌多样性研究

    Institute of Scientific and Technical Information of China (English)

    查仙芳; 沈瑞清; 南宁丽

    2009-01-01

    对宁夏隶属于真菌界锈菌纲(目)的锈菌进行调查、整理,并对宁夏锈菌的分布和寄主进行了初步的多样性分析.调查结果表明,宁夏锈菌有1纲1目6科13属84种,分别寄生于182种植物上,是引起植物锈病的菌源.%Rust fungi in Ningxia were investigated and sort up. There were 84 species, 13 genus, 6 families, 1 order and 1 class of rust fungi which hosted in 182 plants and caused rust diseases. Meanwhile, the diversity of distribution and host was primarily analyzed.

  14. Assessing the Effects of Suomi NPP VIIRS M15/M16 Detector Radiometric Stability and Relative Spectral Response Variation on Striping

    Directory of Open Access Journals (Sweden)

    Zhuo Wang

    2016-02-01

    Full Text Available Modern satellite radiometers have many detectors with different relative spectral response (RSR. Effect of RSR differences on striping and the root cause of striping in sensor data record (SDR radiance and brightness temperature products have not been well studied. A previous study used MODTRAN radiative transfer model (RTM to analyze striping. In this study, we make efforts to find the possible root causes of striping. Line-by-Line RTM (LBLRTM is used to evaluate the effect of RSR difference on striping and the atmospheric dependency for VIIRS bands M15 and M16. The results show that previous study using MODTRAN is repeatable: the striping is related to the difference between band-averaged and detector-level RSR, and the BT difference has some atmospheric dependency. We also analyzed VIIRS earth view (EV data with several striping index methods. Since the EV data is complex, we further analyze the onboard calibration data. Analysis of Variance (ANOVA test shows that the noise along track direction is the major reason for striping. We also found evidence of correlation between solar diffuser (SD and blackbody (BB for detector 1 in M15. Digital Count Restoration (DCR and detector instability are possibly related to the striping in SD and EV data, but further analysis is needed. These findings can potentially lead to further SDR processing improvements.

  15. Leaf stripe resistance of spring barley cultivars

    OpenAIRE

    Pinnschmidt, Hans O; Nielsen, Bent J.

    2006-01-01

    Results of six years of screening trials clearly indicate that effective resistance against barley leaf stripe is available, also in modern cultivars. Among the spring barley cultivars that are currently most widely grown in Denmark, Cabaret, Troon, Sebastian, Justina and Brazil appear most resistant, but only Brazil combines a favourable resistance performance (= low mean and standard deviation of environment-adjusted leaf stripe incidence) with a high number of observations (= years of test...

  16. If I Rest,I Rust

    Institute of Scientific and Technical Information of China (English)

    Orison; Swett; Marden; 陆小丫

    2003-01-01

    选注者言:流水不腐,户枢不蠹。人的才干又何尝不是如此?If I Rest,I Rust 的标题就让我们玩味再三!思之再三,权译:吾“休”则“锈”。宝剑锋从磨砺出, 梅花香自苦寒来。此言非虚!

  17. Modeling Blister Rust Incidence in Whitebark Pine at Northern Rocky Mountain Alpine Treelines: A Geospatial Approach

    OpenAIRE

    Smith, Emily Katherine

    2009-01-01

    The status of whitebark pine (Pinus albicaulis), a foundation and keystone species and a pioneer establisher at alpine treeline, is threatened by the invasive and exotic fungal pathogen (Cronartium ribicola) that causes white pine blister rust in five-needled pines. Originally thought to be limited to moderate environments, the disease is now found extensively throughout colder and dryer regions east of the Continental Divide, including alpine treeline. My research objective was to determine ...

  18. Structural studies on the development of soybean rust (Phakopsora pachyrhizi Syd.) in susceptible soybean leaves

    International Nuclear Information System (INIS)

    Where soybeans are cultivated in the tropics, soybean rust may cause heavy crop losses. Resistance found so far was only of local and temporary value. More substantial breeding efforts are needed, but these may require a better understanding of the pathogen's biology and evolutionary capacity, the infection process and the host-pathogen relationships. The report deals with the infection process and the development of the fungus in a susceptible host variety. (author)

  19. Sugarcane brown rust – determining genetic variation in the pathogen and identifying potential novel sources of resistance

    Science.gov (United States)

    A major reason for the withdrawal of sugarcane cultivars from production in is the breakdown of resistance to brown rust caused by Puccinia melanaocephala. Genetic characterization of diversity among races of P. melanocephala would help in breeding for resistance to the pathogen. Breeding for durabl...

  20. Molecular Mapping of Adult-Plant Race-Specific Leaf Rust Resistance Gene Lr12 in Bread Wheat

    Science.gov (United States)

    Wheat (Triticum aestivum) gene Lr12 provides adult-plant race-specific resistance to leaf rust caused by Puccinia triticina. It is completely linked or identical to Lr31, which confers seedling resistance only when the complementary gene Lr27 is also present. F2 and F2-derived F3 families were devel...

  1. Changing the game: using integrative genomics to probe virulence mechanisms of the stem rust pathogen Puccinia graminis f. sp. tritici

    Science.gov (United States)

    The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt) poses a threat to food security. These concerns have catalyzed an extensive global effort towards controlling this disease. Substantial research and breeding programs target the identifica...

  2. Registration of a male fertility restorer oilseed sunflower germplasm HA-R9 resistant to sunflower rust

    Science.gov (United States)

    The sunflower (Helianthus annuus L.) germplasm HA-R9 (Reg. No.xxx, PI 667595) was developed by the USDA-ARS, Sunflower and Plant Biology Research Unit in collaboration with the Agricultural Experiment Station of North Dakota State University and released in January, 2013. Sunflower rust (caused by P...

  3. Genes for "Reverse" fruit striping in squash (Cucurbita pepo).

    Science.gov (United States)

    Paris, Harry S

    2009-01-01

    Longitudinal striping is a common fruit color pattern in Cucurbita pepo and is conferred by any of several alleles at the light coloration-1 locus. Normally, dark stripes appear over the fruit surface areas between the 10 main subepidermal vein tracts with the lighter background color over and adjacent to these vein tracts. Less commonly, the striping is "reversed," that is, lighter than the background color. The present work was conducted to elucidate the mode of inheritance of reverse striping. The results indicated that reverse striping is conferred by the complementary interaction of an allele for striping with a heretofore unidentified allele at the light coloration-2 locus which is hereby designated l-2(R). Fruits of plants carrying an allele for striping and that are homozygous for l-2(R) have completely reversed striping, whereas those heterozygous for l-2(R) have striping that is completely normal or that is partially normal and partially reversed.

  4. Incomplete resistance to coffee leaf rust (Hemileia vastatrix)

    NARCIS (Netherlands)

    Eskes, T.K.A.B.

    1983-01-01

    Incomplete resistance to coffee leaf rust ( Hemileia vastatrix ) may be of value in obtaining durable resistance, which is of great importance for the perennial coffee crop. Methods were developed to assess incomplete resistance to coffee leaf rust by using illustrated scales ranging from 0 t

  5. Stem rust spores elicit rapid RPG1 phosphorylation

    Science.gov (United States)

    Stem rust threatens cereal production worldwide. Understanding the mechanism by which durable resistance genes, such as Rpg1, function is critical. We show that the RPG1 protein is phosphorylated within 5 min by exposure to spores from avirulent but not virulent races of stem rust. Transgenic mutant...

  6. 77 FR 65840 - Chrysanthemum White Rust Regulatory Status and Restrictions

    Science.gov (United States)

    2012-10-31

    ...; ] DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service 7 CFR Part 319 RIN 0579-AD67 Chrysanthemum White Rust Regulatory Status and Restrictions AGENCY: Animal and Plant Health Inspection Service... chrysanthemum white rust (CWR) outbreaks and the importation of plant material that is a host of CWR. CWR is...

  7. 77 FR 46339 - Chrysanthemum White Rust Regulatory Status and Restrictions

    Science.gov (United States)

    2012-08-03

    ...; ] DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service 7 CFR Part 319 RIN 0579-AD67 Chrysanthemum White Rust Regulatory Status and Restrictions AGENCY: Animal and Plant Health Inspection Service... chrysanthemum white rust (CWR) outbreaks and the importation of plant material that is a host of...

  8. Green rusts in electrochemical and microbially influenced corrosion of steel

    Science.gov (United States)

    Refait, Philippe; Abdelmoula, Mustapha; Génin, Jean-Marie R.; Sabot, René

    2006-06-01

    Green rusts have been identified as corrosion products of steel in neutral or slightly alkaline aqueous media. They were mainly observed in carbonated media, where the carbonated green rust is obtained, and in seawater, where the sulphated variety is obtained. In the first case, the formation of the carbonated green rust competes with that of siderite FeCO 3. It is favoured when the dissolution of iron is accompanied by the reduction of dissolved oxygen and the formation of OH - ions. In the second case, the formation of the sulphated variety competes with that of the chlorinated variety. The sulphated green rust is obtained since the layered structure of green rusts is characterised by a strong affinity for divalent anions. Finally, the oxidation of green rusts leads to the various constituents of 'common' rust. The conditions favouring the formation of a ferric compound keeping the crystal structure of green rusts is discussed. To cite this article: P. Refait et al., C. R. Geoscience 338 (2006).

  9. Evaporation of elongated droplets on chemically stripe-patterned surfaces

    NARCIS (Netherlands)

    Jansen, H.P.; Zandvliet, H.J.W.; Kooij, E.S.

    2015-01-01

    We investigate the evaporation of elongated droplets on chemically striped patterned surfaces. Variation of elongation is achieved by depositing droplets on surfaces with varying ratios of hydrophobic and hydrophilic stripe widths. Elongated droplets evaporate faster than more spherical droplets. Bo

  10. Rust fungi on Annonaceae: the genus Sphaerophragmium.

    Science.gov (United States)

    Beenken, Ludwig; Berndt, Reinhard

    2010-01-01

    Seven species of the rust genus Sphaerophragmium occur on members of the tropical plant family Annonaceae. Uropyxis gerstneri is recombined to S. gerstneri. A new species, S. xylopiae, is described from Xylopia acutiflora. The host plant of S. boanense is identified as Mitrella sp. Sphaerophragmium pulchrum is transferred to Dicheirinia. The anatomy of telia with teliospores and parasitizing mycelium is described and illustrated in detail. A new type of M-haustorium, which emanates laterally from intracellular hypha, is detected in S. monodorae. An identification key is given.

  11. 76 FR 13970 - Notice of Request for Extension of Approval of an Information Collection; Black Stem Rust...

    Science.gov (United States)

    2011-03-15

    ... categorized as either rust-resistant or rust-susceptible. Rust-resistant plants do not pose a risk of... Animal and Plant Health Inspection Service Notice of Request for Extension of Approval of an Information Collection; Black Stem Rust; Identification Requirements for Addition of Rust-Resistant Varieties...

  12. Host jumps shaped the diversity of extant rust fungi (Pucciniales).

    Science.gov (United States)

    McTaggart, Alistair R; Shivas, Roger G; van der Nest, Magriet A; Roux, Jolanda; Wingfield, Brenda D; Wingfield, Michael J

    2016-02-01

    The aim of this study was to determine the evolutionary time line for rust fungi and date key speciation events using a molecular clock. Evidence is provided that supports a contemporary view for a recent origin of rust fungi, with a common ancestor on a flowering plant. Divergence times for > 20 genera of rust fungi were studied with Bayesian evolutionary analyses. A relaxed molecular clock was applied to ribosomal and mitochondrial genes, calibrated against estimated divergence times for the hosts of rust fungi, such as Acacia (Fabaceae), angiosperms and the cupressophytes. Results showed that rust fungi shared a most recent common ancestor with a mean age between 113 and 115 million yr. This dates rust fungi to the Cretaceous period, which is much younger than previous estimations. Host jumps, whether taxonomically large or between host genera in the same family, most probably shaped the diversity of rust genera. Likewise, species diversified by host shifts (through coevolution) or via subsequent host jumps. This is in contrast to strict coevolution with their hosts. Puccinia psidii was recovered in Sphaerophragmiaceae, a family distinct from Raveneliaceae, which were regarded as confamilial in previous studies. PMID:26459939

  13. Genetic analysis of leaf rust resistance in six durum wheat genotypes.

    Science.gov (United States)

    Loladze, Alexander; Kthiri, Dhouha; Pozniak, Curtis; Ammar, Karim

    2014-12-01

    Leaf rust, caused by Puccinia triticina, is one of the main fungal diseases limiting durum wheat production. This study aimed to characterize previously undescribed genes for leaf rust resistance in durum wheat. Six different resistant durum genotypes were crossed to two susceptible International Maize and Wheat Improvement Center (CIMMYT) lines and the resulting F1, F2, and F3 progenies were evaluated for leaf rust reactions in the field and under greenhouse conditions. In addition, allelism tests were conducted. The results of the study indicated that most genotypes carried single effective dominant or recessive seedling resistance genes; the only exception to this was genotype Gaza, which carried one adult plant and one seedling resistance gene. In addition, it was concluded that the resistance genes identified in the current study were neither allelic to LrCamayo or Lr61, nor were they related to Lr3 or Lr14a, the genes that already are either ineffective or are considered to be vulnerable for breeding purposes. A complicated allelic or linkage relationship between the identified genes is discussed. The results of the study will be useful for breeding for durable resistance by creating polygenic complexes. PMID:24906010

  14. A simulation model for epidemics of stem rust in ryegrass seed crops.

    Science.gov (United States)

    Pfender, W F; Upper, D

    2015-01-01

    A simulation model (STEMRUST_G, named for stem rust of grasses) was created for stem rust (caused by Puccinia graminis subsp. graminicola) in perennial ryegrass grown to maturity as a seed crop. The model has a daily time step and is driven by weather data and an initial input of disease severity from field observation. Key aspects of plant growth are modeled. Disease severity is modeled as rust population growth, where individuals are pathogen colonies (pustules) grouped in cohorts defined by date of initiation and plant part infected. Infections due to either aerial spread or within-plant contact spread are modeled. Pathogen cohorts progress through life stages that are modeled as disease cycle components (colony establishment, latent period, infectious period, and sporulation) affected by daily weather variables, plant growth, and fungicide application. Fungicide effects on disease cycle components are modeled for two commonly used active ingredients, applied preinfection or postinfection. Previously validated submodels for certain disease cycle components formed the framework for integrating additional processes, and the complete model was calibrated with field data from 10 stem rust epidemics. Discrepancies between modeled outcomes and the calibration data (log10[modeled]-log10[observed]) had a mean near zero but considerable variance, with 1 standard deviation=0.5 log10 units (3.2-fold). It appears that a large proportion of the modeling error variance may be due to variability in field observations of disease severity. An action threshold for fungicide application was derived empirically, using a constructed weather input file favorable for disease development. The action threshold is a negative threshold, representing a level of disease (latent plus visible) below which damaging levels of disease are unable to develop before the yield-critical crop stage. The model is in the public domain and available on the Internet.

  15. Creation of variation in Basella for rust resistance through mutagenesis

    International Nuclear Information System (INIS)

    African spinach, basella is grown as a leafy vegetable in Central Africa. Basella cultivars belong to the species Basella alba and B. rubra which are seed propagated and are likely Asiatic in origin. Basella alba seeds were irradiated with doses of 50, 100, 200, 300 and 500 Gy to create variation for rust resistance which is caused by the fungus, Uromyces basellae Sidow. The effects of irradiation were investigated on seed germination, plant mortality and height. Seed germination varied from 97% for those irradiated with 50 Gy to 39% with 500 Gy, and LD50 for seed germination was between 300 to 400 Gy. Doses between 50 and 150 Gy did not cause any mortality of plants obtained from irradiated seeds; however, doses between 200 to 500 Gy caused high mortality among such plants. Irradiation with 150 Gy inhibited plant growth by 48% in relation to the growth of control plants. Based on the results, radiation doses above 150 and up to 400 Gy were used for the production of desired variation. (author). 11 refs, 9 figs

  16. Current status, likely migration and strategies to mitigate the threat to wheat production from race UG99 (TTKS) of stem rust pathogen

    Science.gov (United States)

    Stem or black rust, caused by Puccinia graminis tritici, has historically caused severe losses to wheat (Triticum aestivum) production worldwide. Successful control of the disease for over three decades through the use of genetic resistance has resulted in a sharp decline in research activity in rec...

  17. Identification and characterization of resistance to yellow rust and powdery mildew in wild emmer wheat and their transfer to bread wheat.

    NARCIS (Netherlands)

    Silfhout, van C.H.

    1989-01-01

    In wild emmer wheat three different kinds of genes for resistance to yellow rust were found, namely genes causing overall resistance, genes causing adult-plant resistance and genes which induce resistance detectable at higher temperatures. At least eleven different and probably novel major genes for

  18. Incorporation of Monovalent Cations in Sulfate Green Rust

    DEFF Research Database (Denmark)

    Christiansen, B. C.; Dideriksen, K.; Katz, A.;

    2014-01-01

    Green rust is a naturally occurring layered mixed-valent ferrous-ferric hydroxide, which can react with a range of redox-active compounds. Sulfate-bearing green rust is generally thought to have interlayers composed of sulfate and water. Here, we provide evidence that the interlayers also contain...... with water showed that Na+ and K+ were structurally fixed in the interlayer, whereas Rb+ and Cs+ could be removed, resulting in a decrease in the basal layer spacing. The incorporation of cations in the interlayer opens up new possibilities for the use of sulfate green rust for exchange reactions with both...

  19. Slow rusting response of different wheat genotypes against the leaf rust in relation to epidemiological factors in Faisalabad

    International Nuclear Information System (INIS)

    Wheat genotypes were screened against leaf rust to evaluate slow rusting response. Among one hundred and sixty varieties/lines, 86 showed response to leaf rust while all other remained immune or showed no response. The slow rusting, wheat varieties/ lines displayed 20-40% severity level and these were Maxi-Pak65, Blue silver, Pothohar, Punjab81, Faisalabd-83, Shalimar-88, Kohnoor-83, Pasban-90, Inqilab-91, Uqab-99-94105, Punjab-76, Parwaz-94, HD2169, HD2179, HD2204, HD2285, Lr27+31, LrB, LR17, Lr14A, Lr15 and Yr1-E-1 while the fast rusting varieties/lines that showed severity level up to 90% were WL-711, Morocco, PAK-1, Punjab-85 and Chakwal-86 SA42, SA75, Lr1, Lr2A, Lr2B. Lr23, Lr3KA, Lr3g, Lr10, Lr18, Lr21, Lr24, Yr2-E35 and 95153 respectively. Slow rusting genotypes exhibited low AUDPC (200-400) values while fast rusters displayed high AUDPC (400-1500) values. Leaf rust severity displayed significant correlation with maximum and minimum temperatures, rainfall and sunshine radiation. It was observed that with an increase of these environmental conditions a significant increase in disease severity was recorded

  20. Stripe glasses in ferromagnetic thin films

    Science.gov (United States)

    Principi, Alessandro; Katsnelson, Mikhail I.

    2016-02-01

    Domain walls in magnetic multilayered systems can exhibit a very complex and fascinating behavior. For example, the magnetization of thin films of hard magnetic materials is in general perpendicular to the thin-film plane, thanks to the strong out-of-plane anisotropy, but its direction changes periodically, forming an alternating spin-up and spin-down stripe pattern. The latter is stabilized by the competition between the ferromagnetic coupling and dipole-dipole interactions, and disappears when a moderate in-plane magnetic field is applied. It has been suggested that such a behavior may be understood in terms of a self-induced stripe glassiness. In this paper we show that such a scenario is compatible with the experimental findings. The strong out-of-plane magnetic anisotropy of the film is found to be beneficial for the formation of both stripe-ordered and glassy phases. At zero magnetic field the system can form a glass only in a narrow interval of fairly large temperatures. An in-plane magnetic field, however, shifts the glass transition towards lower temperatures, therefore enabling it at or below room temperature. In good qualitative agreement with the experimental findings, we show that a moderate in-plane magnetic field of the order of 50 mT can lead to the formation of defects in the stripe pattern, which sets the onset of the glass transition.

  1. Audiogram of a striped dolphin (Stenella coeruleoalba)

    NARCIS (Netherlands)

    Kastelein, R.A.; Hagedoorn, M.; Au, W.W.L.; Haan, de D.

    2003-01-01

    The underwater hearing sensitivity of a striped dolphin was measured in a pool using standard psycho-acoustic techniques. The go/no-go response paradigm and up¿down staircase psychometric method were used. Auditory sensitivity was measured by using 12 narrow-band frequency-modulated signals having c

  2. Patterns of genomic variation in the poplar rust fungus Melampsora larici-populina identify pathogenesis-related factors

    Directory of Open Access Journals (Sweden)

    Antoine ePersoons

    2014-09-01

    Full Text Available Melampsora larici-populina is a fungal pathogen responsible for foliar rust disease on poplar trees, which causes damage to forest plantations worldwide, particularly in Northern Europe. The reference genome of the isolate 98AG31 was previously sequenced using a whole genome shotgun strategy, revealing a large genome of 101 megabases containing 16,399 predicted genes, which included secreted protein genes representing poplar rust candidate effectors. In the present study, the genomes of 15 isolates collected over the past 20 years throughout the French territory, representing distinct virulence profiles, were characterized by massively parallel sequencing to assess genetic variation in the poplar rust fungus. Comparison to the reference genome revealed striking structural variations. Analysis of coverage and sequencing depth identified large missing regions between isolates related to the mating type loci. More than 611,824 single-nucleotide polymorphism (SNP positions were uncovered overall, indicating a remarkable level of polymorphism. Based on the accumulation of non-synonymous substitutions in coding sequences and the relative frequencies of synonymous and non-synonymous polymorphisms (i.e. PN/PS, we identify candidate genes that may be involved in fungal pathogenesis. Correlation between non-synonymous SNPs in genes encoding secreted proteins and pathotypes of the studied isolates revealed candidate genes potentially related to virulences 1, 6 and 8 of the poplar rust fungus.

  3. Noise-induced striped trajectories of Rossler systems

    Institute of Scientific and Technical Information of China (English)

    Huang Zhi-hua; Dong Ya-Li

    2007-01-01

    In the paper,the generation of striped trajectories in phase space by noise-injection is considered. With suitable amplitudes of noise,the steady-state system orbits appear in rectangular striped shape.The relationship between the shape(including the range and the number of stripes)and some parameters is discussed.The result shows that noise can also generate the striped shape effectively and simply,which is similar to the newly-discovered striped pattern generated by controlled Rossler systems.

  4. Diagonal stripes in the spin glass phase of cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Seibold, G., E-mail: goetz@physik.tu-cottbus.d [Institut fuer Physik, BTU Cottbus, Post Box 101344, 03013 Cottbus (Germany); Lorenzana, J. [SMC-INFM-CNR and Dipartimento di Fisica, Universita di Roma ' La Sapienza' , P.le Aldo Moro 5, I-00185 Roma (Italy)

    2010-12-15

    Based on the unrestricted Gutzwiller approximation we study the possibility that the diagonal incommensurate spin scattering in the spin glass phase of lanthanum cuprates originates from stripe formation. Similar to the metallic phase two types of diagonal stripe structures appear to be stable: (a) site-centered textures which have one hole per site along the stripe and (b) ferromagnetic stair-case structures which are the diagonal equivalent to bond-centered stripes in the metallic phase and which on average have a filling of 3/4 holes per stripe site. We give a detailed analysis of the stability of both diagonal textures with regard to the vertical ones.

  5. Rust disease continues to threaten California garlic crop

    OpenAIRE

    Koike, Steven T.; Smith, Richard; Davis, R. Michael; Nunez, J. Joe; Voss, Ron E.

    2001-01-01

    In 1998, following the very wet EI Niño weather event, a devastating outbreak of rust disease severely damaged the garlic crop in California. The disease also occurred in 1999 and 2000, indicating that rust may have developed into an annual problem. We identified the pathogen as Puccinia allii. In our study, it infected allium crops such as garlic, onion and chives, but not leek, elephant garlic or shallot. Currently registered materials did not control the disease, but tebuconazole (Folicur)...

  6. Corrosion in drinking water pipes: the importance of green rusts.

    Science.gov (United States)

    Swietlik, Joanna; Raczyk-Stanisławiak, Urszula; Piszora, Paweł; Nawrocki, Jacek

    2012-01-01

    Complex crystallographic composition of the corrosion products is studied by diffraction methods and results obtained after different pre-treatment of samples are compared. The green rusts are found to be much more abundant in corrosion scales than it has been assumed so far. The characteristic and crystallographic composition of corrosion scales and deposits suspended in steady waters were analyzed by X-ray diffraction (XRD). The necessity of the examination of corrosion products in the wet conditions is indicated. The drying of the samples before analysis is shown to substantially change the crystallographic phases originally present in corrosion products. On sample drying the unstable green rusts is converted into more stable phases such as goethite and lepidocrocite, while the content of magnetite and siderite decreases. Three types of green rusts in wet materials sampled from tubercles are identified. Unexpectedly, in almost all corrosion scale samples significant amounts of the least stable green rust in chloride form was detected. Analysis of corrosion products suspended in steady water, which remained between tubercles and possibly in their interiors, revealed complex crystallographic composition of the sampled material. Goethite, lepidocrocite and magnetite as well as low amounts of siderite and quartz were present in all samples. Six different forms of green rusts were identified in the deposits separated from steady waters and the most abundant was carbonate green rust GR(CO(3)(2-))(I).

  7. Geysers from the Tiger Stripes of Enceladus

    Science.gov (United States)

    Kohler, Susanna

    2015-10-01

    Enceladus, the sixth-largest moon of Saturn, is a cold, icy world but its also remarkably active. Recent studies have charted over a hundred geysers venting gas and dust into space from Enceladus south polar region. New research addresses the question of how the moons extreme surface terrain influences the locations and behavior of these geysers.Active PlumesEnceladus orbiting within Saturns E ring. Enceladus plumes probably created this ring. [NASA/JPL/Space Science Institute]A decade ago, scientists discovered that Enceladus south polar region is home to a prominent set of four fractures known as the tiger stripes. This region was found to contain roughly 100 geyser jets, which form plumes of gas and dust venting into space at a combined rate of ~200 kilograms per second! These plumes are probably the source of the material in Saturns E ring, in which Enceladus orbits.Recently, Carolyn Porco (UC Berkeley and CICLOPS Space Science Institute) led a study that analyzed 6.5 years of Cassini data, surveying the locations and orientations of 101 geysers. The outcome was peculiar: the geysers are distributed along the tiger stripes, but their directions are not all pointing vertically from the surface (see the video below!).Now, Paul Helfenstein (Cornell University) has teamed up with Porco to examine whether the surface terrain surrounding the geysers affects where the jets erupt, what direction they point, and even when theyre active.Surface InfluenceHelfenstein and Porco demonstrate that the locations and behavior of the geysers are very likely influenced by Enceladus surface features in this region. In particular, they find:The spacing of the geyser jets on Enceladus is not random.The jets are roughly uniformly distributed along the three most active tiger stripes, spaced about 5 kilometers apart. This fixed spacing might be due to shear fractures produced by fault motion along the tiger stripes cutting across the stripes at regular intervals and providing

  8. Relation Between Open Circuit Potential and Polarization Resistance with Rust and Corrosion Monitoring of Mild Steel

    Science.gov (United States)

    Choudhary, S.; Garg, A.; Mondal, K.

    2016-07-01

    The present work discusses continuous corrosion assessment from a unique correlation of open circuit potential (OCP) and linear polarization resistance with rust formation on mild steel after prolong exposure in 3.5% NaCl salt fog environment. The OCP measurement and linear polarization tests were carried out of the rusted samples only without the removal of rust. It also discusses the strong influence of the composition, fraction, and morphology of the rust layers with OCP and linear polarization resistance. The rust characterization was done after the measurement of OCP and linear polarization resistance of the rusted steel samples. Therefore, monitoring of both the OCP and linear polarization resistance of the rusted mild steels coupled with rust characterization could be used for easy and dynamic assessment of the nature of corrosion.

  9. Urediospores of Puccinia spp. and other rusts are warm-temperature ice nucleators and harbor ice nucleation active bacteria

    OpenAIRE

    A. R. Moukahel; Gonçalves, F.L.T.; Asaad, S.; Samsatly, J.; Glaux, C.; Sands, D C; C. E. Morris; Bigg, E. K.

    2012-01-01

    In light of various features of the biology of the rust fungi and of the epidemiology of the plant diseases they cause that illustrate the important role of rainfall in their life history, we have characterized the ice nucleation activity (INA) of the aerially disseminated spores (urediospores) of this group of fungi. Urediospores of this obligate plant parasite were collected from natural infections from 7 species of weeds in France, from coffee in Brazil and from field and greenhouse...

  10. Urediospores of rust fungi are ice nucleation active at > −10 °C and harbor ice nucleation active bacteria

    OpenAIRE

    C. E. Morris; Sands, D C; Glaux, C.; Samsatly, J.; Asaad, S.; A. R. Moukahel; Gonçalves, F.L.T.; Bigg, E. K.

    2013-01-01

    Various features of the biology of the rust fungi and of the epidemiology of the plant diseases they cause illustrate the important role of rainfall in their life history. Based on this insight we have characterized the ice nucleation activity (INA) of the aerially disseminated spores (urediospores) of this group of fungi. Urediospores of this obligate plant parasite were collected from natural infections of 7 species of weeds in France, from coffee in Brazil and from field and greenhouse-gro...

  11. A plant gene up-regulated at rust infection sites.

    Science.gov (United States)

    Ayliffe, Michael A; Roberts, James K; Mitchell, Heidi J; Zhang, Ren; Lawrence, Gregory J; Ellis, Jeffrey G; Pryor, Tony J

    2002-05-01

    Expression of the fis1 gene from flax (Linum usitatissimum) is induced by a compatible rust (Melampsora lini) infection. Infection of transgenic plants containing a beta-glucuronidase (GUS) reporter gene under the control of the fis1 promoter showed that induction is highly localized to those leaf mesophyll cells within and immediately surrounding rust infection sites. The level of induction reflects the extent of fungal growth. In a strong resistance reaction, such as the hypersensitive fleck mediated by the L6 resistance gene, there is very little fungal growth and a microscopic level of GUS expression. Partially resistant flax leaves show levels of GUS expression that were intermediate to the level observed in the fully susceptible infection. Sequence and deletion analysis using both transient Agrobacterium tumefaciens expression and stable transformation assays have shown that the rust-inducible fis1 promoter is contained within a 580-bp fragment. Homologs of fis1 were identified in expressed sequence tag databases of a range of plant species including dicots, monocots, and a gymnosperm. Homologous genes isolated from maize (Zea mays; mis1), barley (Hordeum vulgare; bis1), wheat (Triticum aestivum; wis1), and Arabidopsis encode proteins that are highly similar (76%-82%) to the FIS1 protein. The Arabidopsis homologue has been reported to encode a delta1-pyrroline-5-carboxylate dehydrogenase that is involved in the catabolism of proline to glutamate. RNA-blot analysis showed that mis1 in maize and the bis1 homolog in barley are both up-regulated by a compatible infection with the corresponding species-specific rust. The rust-induced genes homologous to fis1 are present in many plants. The promoters of these genes have potential roles for the engineering of synthetic rust resistance genes by targeting transgene expression to the sites of rust infection.

  12. Determining the order of resistance genes against Stagonospora nodorum blotch, Fusarium head blight and stem rust on wheat chromosome 3BS

    Science.gov (United States)

    Fungal diseases of wheat occur every year in the U.S., leading to significant grain yield losses. Stagonospora nodorum blotch (SNB), Fusarium head blight (FHB) and stem rust (SR) are caused by the fungi Stagonospora nodorum, Fusarium graminearum and Puccinia graminis, respectively. These leaf and he...

  13. Below-ground plant parts emit herbivore-induced volatiles: olfactory responses of a predatory mite to tulip bulbs infested by rust mites

    NARCIS (Netherlands)

    N.S. Aratchige; I. Lesna; M.W. Sabelis

    2004-01-01

    Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract pred

  14. Rph22: mapping of a novel leaf rust resistance gene introgressed from the non-host Hordeum bulbosum L. into cultivated barley (Hordeum vulgare L.)

    NARCIS (Netherlands)

    Johnston, P.A.; Niks, R.E.; Meiyalaghan, V.; Blanchet, E.; Pickering, R.

    2013-01-01

    A resistance gene (Rph22) to barley leaf rust caused by Puccinia hordei was introgressed from the non-host species Hordeum bulbosum into cultivated barley. The H. bulbosum introgression in line ‘182Q20’ was located to chromosome 2HL using genomic in situ hybridisation (GISH). Using molecular markers

  15. Rust fungi on some poaceous weeds of wheat crops in Pakistan

    OpenAIRE

    NAJAM-UL-SEHAR AFSHAN*; ABDUL REHMAN NIAZI

    2013-01-01

    The article enlists common poaceous weeds found in wheat crop sand their specific parasitic rust fungi. In this study, four (04) plant taxa of Poaceae infected with rust fungi are collected from different wheat crops grown in different areas of Pakistan. The rust fungi are isolated, characterized and identified. All these host plants are known weeds of wheat crop in Pakistan. This work would help to identify and enlist the potential rust fungi on weeds of wheat crop that could be utilized to ...

  16. Capillary flow driven gradient generation in fluid stripes for biomaterial and biomedical applications

    Science.gov (United States)

    Hancock, Matthew; He, Jiankang; Piraino, Francesco; Camci-Unal, Gulden; Khademhosseini, Ali

    2011-11-01

    A simple and inexpensive bench-top method is presented employing passive mechanisms to generate centimeters-long gradients of molecules and particles in under a second with only a coated glass slide and a micropipette. By patterning hydrophilic regions on a substrate, a stripe of prepolymer solution is held in place on a glass slide by a hydrophobic boundary. Adding a droplet to one end of this ``pre-wet'' stripe causes a rapid capillary flow that spreads the droplet along the stripe to generate a gradient in the relative concentrations of the droplet and pre-wet solutions. Experiments and theoretical models characterize the flows and gradient profiles and their dependence on the fluid volumes, properties, and stripe geometry. A bench-top rapid prototyping method allows the user to design and fabricate the coated slides using only tape and hydrophobic spray. Gradient biomaterials are produced by crosslinking gradients of prepolymer solutions. Applications include producing a soluble drug gradient over cells in shear-protected microwells, generating a concentration gradient of cells encapsulated in three dimensions within a homogeneous biopolymer, and synthesizing a biomaterial with encapsulated cells exhibiting a gradient in cell spreading.

  17. Effects of different heat treatments on lipid quality of striped catfish (Pangasius hypophthalmus

    Directory of Open Access Journals (Sweden)

    Zdzisław Domiszewski

    2011-09-01

    Full Text Available   Background. As a result of consumer acceptance and low price production, sales of striped catfish fillets continue to grow. Striped catfish fillets, due to their white meat and lack of fish scent, can be an alternative to fish such as cod or hake. The paper analysed the influence of four different kinds of heat treatment: boiling with and without the addition of salt, frying, microwave cooking, microwave cooking without water on the composition of fatty acids and the lipid oxidation and hydrolysis level of striped catfish fillets. Material and methods. Assays were performed on striped catfish fillets (Pangasius hypophthalmus, Sauvage 1878, which were bought from local supermarket. Fillets one year before expiration date were assayed. Quality of fish lipids was determined by an analysis of the following factors: peroxide value (PV, anisidine value (AsV, TOTOX value, conjugated dienes (CD, acid value (AV, along with an analysis of the composition of fatty acid (FA via gas chromatography. Results. It was shown that conventional cooking and microwave cooking of striped catfish fillets results in an approximately 10% change in the amount of PUFA, including EPA and DHA, whereas the percentages of SFA and MUFA remain unchanged. The amount of the sum of EPA and DHA in 100 g of raw fillet was 16.5 mg, whereas after conventional cooking, microwave cooking and frying the sum of EPA and DHA was respectively: 12, 22 and 23 mg. It was observed that conventional cooking causes an average 10% loss of fat, a change not observed in case of microwave cooking. In spite of a substantial influence of heat treatment on the amount of both primary and secondary oxidation products, striped catfish lipids maintained good quality after the treatment – PV of every sample was below 3 meq O2/kg lipids, and AsV below 1.5. The addition of salt during boiling caused a 16-fold increase in the amount of peroxides and a fourfold increase in the amount of secondary oxidation

  18. The fundamental thermal niche of adult landlocked striped bass

    Science.gov (United States)

    Bettoli, P.W.

    2005-01-01

    Researchers have described the temperatures selected by landlocked striped bass Morone saxatilis in different locales throughout the USA. However, seasonally low concentrations of dissolved oxygen (DO) in many systems prevented striped bass from using the cool waters (literature estimates. These results also represent the first unbiased field estimates of the influence of season on the thermal ecology of adult striped bass. The thermal characteristics of habitats considered optimal in habitat suitability index models for adult landlocked striped bass (i.e., 18-24??C) should be revised to include cooler waters. ?? Copyright by the American Fisheries Society 2005.

  19. Molecular cloning and characterization of two hypersensitive induced reaction genes from wheat infected by stripe rust pathogen

    Science.gov (United States)

    A novel gene induced during hypersensitive reaction (HIR) in wheat was identified using in silico cloning and designated as TaHIR2. The TaHIR2 gene was deduced to encode a 284-amino acid protein, whose molecular mass and isoelectric point (pI) were 31.05 kD and 5.18, respectively. Amino acid sequenc...

  20. Selection of Arabic coffee progenies with rust resistance

    Directory of Open Access Journals (Sweden)

    Gustavo Hiroshi Sera

    2014-07-01

    Full Text Available The aim of this study was to select high-yielding coffee progenies with resistance to coffee leaf rust for the State of Paraná (Brazil. Field experiments in a randomized block design were carried out in Itaguajé and Congonhinhas. Yield, vegetative vigor and rust resistance of nine progenies of Arabic coffee and three check cultivars were evaluated. Many genotypes derived from “Sarchimor” and “Catucaí” were susceptible. Three coffee genotypes of Sarchimor germplasm and the F6 generation of genotype “Catuaí x (Catuaí x BA-10 coffee” were selected to advance generations and are promising to become new cultivars for being higher-yielding than ‘IAPAR 59’ and ‘Tupi IAC 1669-33’ and having a large number of plants with complete rust resistance.

  1. Wheat Rust Information Resources - Integrated tools and data for improved decision making

    DEFF Research Database (Denmark)

    Hodson, David; Hansen, Jens Grønbech; Lassen, Poul;

    Wheat rusts present an ever-changing global threat to the worlds wheat crop. Emergence of virulent new races in one region has implications for other regions, due to wind-borne or human-borne movements. Therefore informed decision making regarding control and mitigation of wheat rusts requires...... giving access to an unprecedented set of data for rust surveys, alternate hosts (barberry), rust pathotypes, trap nurseries and resistant cultivars. Standardized protocols for data collection have permitted the development of a comprehensive data management system, named the Wheat Rust Toolbox...

  2. Anisotropic flow in striped superhydrophobic channels

    CERN Document Server

    Zhou, Jiajia; Schmid, Friederike; Vinogradova, Olga I

    2012-01-01

    We report results of dissipative particle dynamics simulations and develop a semi-analytical theory and of an anisotropic flow in a parallel-plate channel with two superhydrophobic striped walls. Our approach is valid for any local slip at the gas sectors and an arbitrary distance between the plates, ranging from a thick to a thin channel. It allows us to optimize area fractions, slip lengths, channel thickness and texture orientation to maximize a transverse flow. Our results may be useful for extracting effective slip tensors from global measurements, such as the permeability of a channel, in experiments or simulations, and may also find applications in passive microfluidic mixing.

  3. Weather and Climate Indicators for Coffee Rust Disease

    Science.gov (United States)

    Georgiou, S.; Imbach, P. A.; Avelino, J.; Anzueto, F.; del Carmen Calderón, G.

    2014-12-01

    Coffee rust is a disease that has significant impacts on the livelihoods of those who are dependent on the Central American coffee sector. Our investigation has focussed on the weather and climate indicators that favoured the high incidence of coffee rust disease in Central America in 2012 by assessing daily temperature and precipitation data available from 81 weather stations in the INSIVUMEH and ANACAFE networks located in Guatemala. The temperature data were interpolated to determine the corresponding daily data at 1250 farms located across Guatemala, between 400 and 1800 m elevation. Additionally, CHIRPS five day (pentad) data has been used to assess the anomalies between the 2012 and the climatological average precipitation data at farm locations. The weather conditions in 2012 displayed considerable variations from the climatological data. In general the minimum daily temperatures were higher than the corresponding climatology while the maximum temperatures were lower. As a result, the daily diurnal temperature range was generally lower than the corresponding climatological range, leading to an increased number of days where the temperatures fell within the optimal range for either influencing the susceptibility of the coffee plants to coffee rust development during the dry season, or for the development of lesions on the coffee leaves during the wet season. The coffee rust latency period was probably shortened as a result, and farms at high altitudes were impacted due to these increases in minimum temperature. Factors taken into consideration in developing indicators for coffee rust development include: the diurnal temperature range, altitude, the environmental lapse rate and the phenology. We will present the results of our study and discuss the potential for each of the derived weather and climatological indicators to be used within risk assessments and to eventually be considered for use within an early warning system for coffee rust disease.

  4. [Specific molecular markers of the rust resistance gene M4 in flax].

    Science.gov (United States)

    Bo, Tian-Yue; Ye, Hua-Zhi; Wang, Shi-Quan; Yang, Jian-Chun; Li, Xiao-Bing; Zhai, Wen-Xue

    2002-10-01

    Flax (Linum usitatissimum L.) is an important fiber and oil-producing crop. Flax rust, caused by Melampsora lini Ehrenb. Lev., occurs worldwide and can cause severe losses in seed yield and fiber quality. In order to identify molecular markers linked to the flax rust resistant gene M4, RAPD analysis of NM4, a near-isogenic line containing the M4 gene, and the recurrent parent Bison was carried out with 540 decamer primers. The primer OPA18 could stably amplify a specific fragment, OPA18(432), in the NM4 line. The OPA18(432) marker was testified to be closely linked to the M4 gene with a genetic distance of 2.1 cM through the analysis of the F2 mapping population derived from a cross of Bison x NM4. Based on the sequence of OPA18(432), the specific PCR primers were designed, and a SCAR marker for the M4 gene was produced. Amplification of different resistant materials proved that the maker is specific for the M4 gene. This marker has been used successfully in marker-assisted selection in the flax breeding program. PMID:12561479

  5. Critical assessment of the evidence for striped nanoparticles

    CERN Document Server

    Stirling, Julian; Sweetman, Adam; Djuranovic, Predrag; Guo, Quanmin; Granwehr, Josef; Lévy, Raphaël; Moriarty, Philip

    2013-01-01

    There is now a significant body of literature in which it is claimed that stripes form in the ligand shell of suitably functionalised Au nanoparticles. This stripe morphology has been proposed to strongly affect the physicochemical and biochemical properties of the particles. We critique the published evidence for striped nanoparticles in detail, with a particular focus on the interpretation of scanning tunnelling microscopy (STM) data (as this is the only technique which ostensibly provides direct evidence for the presence of stripes). Through a combination of an exhaustive re-analysis of the original data with new experimental measurements of a simple control sample comprising entirely unfunctionalised particles, we conclusively show that all of the STM evidence for striped nanoparticles published to date can instead be explained by a combination of well-known instrumental artefacts, strong observer bias, and/or improper data acquisition/analysis protocols. We also critically re-examine the evidence for the...

  6. Genetic analysis and SSR mapping of stem rust resistance gene from wheat mutant D51

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Wheat (Triticum aestivum L.) stem rust caused by Puccinia graminis f.sp.tritici is one of the main diseases of wheat worldwide.Wheat mutant line D51,which forms a highly susceptive cultivar 'L6239' to the three races notated and cultured with immature embryos,shows resistance to prevailing races 21C3CPH,21C3CKH,and 21C3CTR of P.graminis f.sp.tritici in China.In this study,the number and the expression stages of the resistance genes in mutant D51 were studied using inoculation identification and microsatellite (SSR) marker analysis.Two F1 populations from the crosses of D51×L6239 (60 individuals) and D51 × Chinese Spring (60 individuals),their F2 populations (185 and 175 individuals respectively) at the seedling stage,and one F2 population derived from the cross of D51×L6239 (194 individuals) at the adult stage were inoculated with pathogen race 21C3CPH to test for resistance.All F1 individuals of the two crosses were immune to stem rust at both seedling and adult stages.The response pattern of the three F2 populations showed that the R:S segregation ratio was 3:1,suggesting that the stem rust resistance of D51 is controlled by a single dominant gene,and is expressed during the entire growth period.The identification of the stem rust resistance by the F3 progeny test confirmed the credibility of the F2 population test.Segregating populations and small population analyses were used to identify chromosomal regions and molecular markers linked to the gene by the SSR marker method.A total of 675 SSR markers and 185 individuals of the D51 x L6239 F2 population were used to search genetically linked markers to the target gene.Using Mapmaker 3.0 and Map-draw with Kosambi's function and other options set at default values,molecular mapping revealed that the gene was located on chromosome 5DS,linked with and flanked by two SSR markers,Xgwml90 and Xwmc150,at 18.58 and 21.33 cM,respectively.It has been reported that only one stem rust resistant gene,Sr30,is located on the

  7. Deletion mutation as a means of isolating avirulence genes in flax rust.

    Science.gov (United States)

    Timmis, J N; Whisson, D L; Binns, A M; Mayo, M J; Mayo, G M

    1990-05-01

    The interaction between flax rust,Melampsora lini, and its host, flax,Linum usitatissimum, has been extensively studied, and certain genetic features make the system an appropriate choice to utilize in isolating genes conferring avirulence in rust. A mutant that was selected for virulence on Lx plants was isolated, after treatment with gamma rays, from a strain that is genotypicallyA-L5,A-L6,A-L7,A-Lx/A-L5,A-L6,a-L7,a-Lx. These four specificities are tightly linked. Breeding tests showed that this mutant was genotypicallyA-L5,A-L6,a-L7,a-Lx/a-L5,a-L6,a-L7,a-Lx and, when made homozygous for the mutant chromosome, was virulent onL5,L6,L7, andLx. This result excludes somatic recombination as a source of the mutation and indicates deletion as a likely cause. A 250 bp genomic sequence from a strain of rust homozygous for these four linked avirulence genes (A-L5,A-L6,A-L7,A-Lx) was isolated, using a method that allows the differential cloning of the specific DNA sequences located within a deletion in the mutant genome. This clone hybridized to two EcoRI bands in genomic DNA from the strain homozygous for the four linked avirulence genes and from the strain homozygousA-L5 andA-L6 and heterozygousA-L7 andA-Lx, but showed no homology to DNA from the strain carrying the putative chromosomal deletion. The correlation between the genetically characterized deletion mutation and the isolation of a sequence from within a region of chromosome missing from this strain of rust suggests that this 250 bp tract may be part of, or closely linked to, the defined set of avirulence genes. PMID:24226362

  8. Reductive and sorptive properties of sulfate green rust (GRSO4)

    DEFF Research Database (Denmark)

    Nedel, Sorin

    The Fe(II), Fe(III) hydroxide containing sulfate in its structure, called sulfate green rust (GRSO4), can effectively reduce and convert contaminants to less mobile and less toxic forms. However, the ability of GRSO4 to remove positively charged species from solution, via sorption, is very limited...

  9. Transformation of Chlorinated Hydrocarbons on Synthetic Green Rusts

    Science.gov (United States)

    Green rusts (GRs) are layered double hydroxides that contain both ferrous and ferric ions in their structure. GRs can potentially serve as a chemical reductant for degradation of chlorinated hydrocarbons. GRs are found in zerovalent iron based permeable reactive barriers and in c...

  10. Improvement of wheat in Zambia using incomplete resistance against rusts

    NARCIS (Netherlands)

    Milliano, de W.A.J.

    1983-01-01

    The programme of wheat improvement developed in Zambia used local facilities (finance, personnel, infrastructure), low budget, and few personnel. Incomplete resistance against rusts was used to obtain durable resistance.The abiotic conditions, socio-economic status of the farmers, cropping methods,

  11. Facilitation of Rice Stripe Virus Accumulation in the Insect Vector by Himetobi P Virus VP1

    Directory of Open Access Journals (Sweden)

    Shuo Li

    2015-03-01

    Full Text Available The small brown planthopper (SBPH is the main vector for rice stripe virus (RSV, which causes serious rice stripe disease in East Asia. To characterize the virus-vector interactions, the SBPH cDNA library was screened with RSV ribonucleoprotein (RNP as bait using a GAL4-based yeast two-hybrid system. The interaction between RSV-RNP and the Himetobi P virus (HiPV, an insect picorna-like virus VP1 protein was identified. The relationships between HiPV and RSV in SBPH were further investigated, and the results showed that the titer of RSV was commonly higher in single insect that exhibited more VP1 expression. After the VP1 gene was repressed by RNA silencing, the accumulation of RSV decreased significantly in the insect, whereas the virus acquisition ability of SBPH was unaffected, which suggests that HiPV VP1 potentially facilitates the accumulation of RSV in SBPH.

  12. Systemic herpesvirus and morbillivirus co-infection in a striped dolphin (Stenella coeruleoalba).

    Science.gov (United States)

    Soto, S; González, B; Willoughby, K; Maley, M; Olvera, A; Kennedy, S; Marco, A; Domingo, M

    2012-01-01

    During 2007 a dolphin morbillivirus epizootic affected the western Mediterranean and several striped dolphins (Stenella coeruleoalba) stranded on the Catalonian coasts. One of those animals had severe lymphoid depletion, necrosis and syncytial formation in lymph nodes and spleen, with large basophilic nuclear inclusions compatible with herpesvirus detected by immunohistochemical and ultrastructural examination. Non-suppurative encephalitis with associated morbillivirus antigen and morbillivirus antigen within alveolar macrophages were also observed. A pan-herpesvirus nested polymerase chain reaction amplified a sequence virtually identical to two cetacean herpesvirus sequences previously identified in systemic infections in an Atlantic Cuvier's beaked whale (Ziphius cavirostris) and in a Mediterranean striped dolphin. The herpesviral infection was probably secondary to the immunosuppression caused by the morbillivirus. To our knowledge, this is the first report of a cetacean co-infected by dolphin morbillivirus and herpesvirus with evidence of lesions attributable to both viruses.

  13. Critical assessment of the evidence for striped nanoparticles.

    Science.gov (United States)

    Stirling, Julian; Lekkas, Ioannis; Sweetman, Adam; Djuranovic, Predrag; Guo, Quanmin; Pauw, Brian; Granwehr, Josef; Lévy, Raphaël; Moriarty, Philip

    2014-01-01

    There is now a significant body of literature which reports that stripes form in the ligand shell of suitably functionalised Au nanoparticles. This stripe morphology has been proposed to strongly affect the physicochemical and biochemical properties of the particles. We critique the published evidence for striped nanoparticles in detail, with a particular focus on the interpretation of scanning tunnelling microscopy (STM) data (as this is the only technique which ostensibly provides direct evidence for the presence of stripes). Through a combination of an exhaustive re-analysis of the original data, in addition to new experimental measurements of a simple control sample comprising entirely unfunctionalised particles, we show that all of the STM evidence for striped nanoparticles published to date can instead be explained by a combination of well-known instrumental artefacts, or by issues with data acquisition/analysis protocols. We also critically re-examine the evidence for the presence of ligand stripes which has been claimed to have been found from transmission electron microscopy, nuclear magnetic resonance spectroscopy, small angle neutron scattering experiments, and computer simulations. Although these data can indeed be interpreted in terms of stripe formation, we show that the reported results can alternatively be explained as arising from a combination of instrumental artefacts and inadequate data analysis techniques. PMID:25402426

  14. Critical assessment of the evidence for striped nanoparticles.

    Directory of Open Access Journals (Sweden)

    Julian Stirling

    Full Text Available There is now a significant body of literature which reports that stripes form in the ligand shell of suitably functionalised Au nanoparticles. This stripe morphology has been proposed to strongly affect the physicochemical and biochemical properties of the particles. We critique the published evidence for striped nanoparticles in detail, with a particular focus on the interpretation of scanning tunnelling microscopy (STM data (as this is the only technique which ostensibly provides direct evidence for the presence of stripes. Through a combination of an exhaustive re-analysis of the original data, in addition to new experimental measurements of a simple control sample comprising entirely unfunctionalised particles, we show that all of the STM evidence for striped nanoparticles published to date can instead be explained by a combination of well-known instrumental artefacts, or by issues with data acquisition/analysis protocols. We also critically re-examine the evidence for the presence of ligand stripes which has been claimed to have been found from transmission electron microscopy, nuclear magnetic resonance spectroscopy, small angle neutron scattering experiments, and computer simulations. Although these data can indeed be interpreted in terms of stripe formation, we show that the reported results can alternatively be explained as arising from a combination of instrumental artefacts and inadequate data analysis techniques.

  15. Rotational Electrophoresis of Striped Metallic Microrods

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K A; Meier, J A; Dougherty, G M; Santiago, J G

    2005-11-28

    Analytical models are developed for the translation and rotation of metallic rods in a uniform electric field. The limits of thin and thick electric double layers are considered. These models include the effect of stripes of different metals along the length of the particle. Modeling results are compared to experimental measurements for metallic rods. Experiments demonstrate the increased alignment of particles with increasing field strength and the increase in degree of alignment of thin versus thick electric double layers. The metal rods polarize in the applied field and align parallel to its direction due to torques on the polarized charge. The torque due to polarization has a second order dependence on the electric field strength. The particles are also shown to have an additional alignment torque component due to non-uniform densities along their length. The orientation distributions of dilute suspensions of particles are also shown to agree well with results predicted by a rotational convective-diffusion equation.

  16. Comparison of barley stripe mosaic virus strains.

    Science.gov (United States)

    Hafez, Elsayed E; Abdel Aleem, Engy E; Fattouh, Faiza A

    2008-01-01

    BSMV (barley stripe mosaic virus) particles were obtained in a pure state from infected host plant tissues of Hordeum vulgare. The three genomic parities (alpha, beta and gamma) were amplified by PCR using specific primers for each particle; each was cloned. Partial sequence of the alpha, beta and gamma segments was determined for the Egyptian isolate of barley stripe mosaic virus (BSMV AE1). Alignment of nucleotide sequences with that of other known strains of the virus, BSMV type strains (CV17, ND18 and China), and the generation of phylogenetic trees was performed. A low level of homology was detected comparing 467 bp of the a and 643 bp of the segments to that of the other strains, and thus BSMV alpha and beta segments were in separate clusters. However, 1154 bp of the gamma segments of BSMV AE1 showed a high level of homology especially to strain BSMV ND18, as they both formed a distinct cluster. Northern blotting of pure BSMV AE1 virus and H. vulgare-infected tissue were compared using an alpha ND18 specific probe. Western blotting using antibodies specific for the coat protein (CP) and the triple gene block 1 (TGB1) protein, which are both encoded by the beta ND18 segment, still indicated a high level of similarity between proteins produced by BSMV ND18 and AE1. We suggest that the BSMV AE1 isolate is a distinct strain of BSMV which reflects the genetic evolutionary divergence among BSMV strains and members of the Hordeivirus group. PMID:18533473

  17. GENETICS OF STEM RUST RESISTANCE IN THE SPRING WHEAT CULTIVAR THATCHER AND THE ENHANCEMENT OF STEM RUST RESISTANCE BY LR34

    Science.gov (United States)

    Three recombinant inbred line populations from the crosses RL6071/Thatcher, RL6071/RL6058 (Thatcher Lr34), and Thatcher/RL6058, were used to study the genetics of stem rust resistance in Thatcher. Segregation of stem rust resistance in each population was used to determine the number of genes confer...

  18. 金属防锈剂的防锈性能及试验验证%Anti-Rust Properties and Test Validation of Metal Anti-Rust Agents

    Institute of Scientific and Technical Information of China (English)

    侯万果; 王子君; 田前进

    2014-01-01

    The effects of types of anti-rust agents,surfactants,water quality and pH on anti-rust properties of metal anti-rust agents are discussed through analyzing anti-rust mechanism for metal anti-rust agents,and the test verifi-cation is conducted.The results show that in a certain range,the anti-rust properties of metal anti-rust agents with the same or similar molecular structure are improved with the growth of carbon chain.When the molecular structure contains a hydrophobic hydrocarbon group of appropriate length,the anti -rust properties are improved with the in-crease of polar group.The certain surfactants will reduce the anti-rust properties of anti-rust agents.With respect to the distilled water,the tap water reduces the anti-rust properties of metal anti-rust agents.The metal anti-rust a-gents have good anti-rust effect on the 10#steel,brass and aluminum LY12 as pH is 8~8.5.%通过分析金属防锈剂的防锈机理,探讨了防锈剂种类、表面活性剂、水质和 pH值对金属防锈剂防锈性能的影响,并进行了试验验证。结果表明,在一定范围内相同或相似分子结构金属防锈剂的防锈性能随碳链的增长而不断提高;当分子结构中含有适当长度疏水性烃基时,其防锈性能随极性基团的增加而有所提高;某些表面活性剂会降低防锈剂的防锈性能;相对于蒸馏水,自来水则会削弱金属防锈剂的防锈性能;pH值为8~8.5时金属防锈剂对10#钢、黄铜和LY12铝均有较好的防锈效果。

  19. Kinetics of structural rust transformation in environments containing chloride and SO2

    International Nuclear Information System (INIS)

    The behaviour of the rusts produced on low carbon steel exposed in industrial atmospheres, at different distances from the sea, was studied by simulating the wetting-drying cycle in a CEBELCOR type apparatus. Coupons electrode potential was monitored and rust layer was analyzed by gravimetric techniques, optical microscopy and Moessbauer spectroscopy. A particular chloride/sulfur ratio in the atmosphere was found, for which there is a particular behaviour in rust formation. For this ratio, corrosion rates were much less than expected. it is postulated a kinetic mechanism for rust layer formation as the origin of this special behavior. An electrode potential similar to that in a weathering steel was observed, this is reflected in the low corrosion rate obtained. The proposed kinetic mechanism for rust formation under these exposure conditions enables new research lines on layer formation and the development of protective rust for industrial marine atmospheres. (Author) 8 refs

  20. Reduction of Uncorrelated Striping Noise—Applications for Hyperspectral Pushbroom Acquisitions

    Directory of Open Access Journals (Sweden)

    Christian Rogass

    2014-11-01

    Full Text Available Hyperspectral images are of increasing importance in remote sensing applications. Imaging spectrometers provide semi-continuous spectra that can be used for physics based surface cover material identification and quantification. Preceding radiometric calibrations serve as a basis for the transformation of measured signals into physics based units such as radiance. Pushbroom sensors collect incident radiation by at least one detector array utilizing the photoelectric effect. Temporal variations of the detector characteristics that differ with foregoing radiometric calibration cause visually perceptible along-track stripes in the at-sensor radiance data that aggravate succeeding image-based analyses. Especially, variations of the thermally induced dark current dominate and have to be reduced. In this work, a new approach is presented that efficiently reduces dark current related stripe noise. It integrates an across-effect gradient minimization principle. The performance has been evaluated using artificially degraded whiskbroom (reference and real pushbroom acquisitions from EO-1 Hyperion and AISA DUAL that are significantly covered by stripe noise. A set of quality indicators has been used for the accuracy assessment. They clearly show that the new approach outperforms a limited set of tested state-of-the-art approaches and achieves a very high accuracy related to ground-truth for selected tests. It may substitute recent algorithms in the Reduction of Miscalibration Effects (ROME framework that is broadly used to reduce radiometric miscalibrations of pushbroom data takes.

  1. Thermal striping in nuclear reactors: POD analysis of LES simulations and experiment

    Science.gov (United States)

    Merzari, Elia; Alvarez, Andres; Marin, Oana; Obabko, Aleksandr; Lomperski, Steve; Aithal, Shashi

    2015-11-01

    Thermal fatigue caused due to thermal striping impacts design and analyses of a wide-range of industrial apparatus. This phenomena is of particular significance in nuclear reactor applications, primarily in sodium cooled fast reactors. In order to conduct systematic analyses of the thermal striping phenomena a simplified experimental set-up was designed and built at Argonne National Laboratory. In this set-up two turbulent jets with a temperature difference of about 20K were mixed in a rectangular tank. The jets entered the tank via 2 hexagonal inlets. Two different inlet geometries were studied, both experimentally and via high-fidelity LES simulations. Proper Orthogonal Decomposition (POD) was performed on the turbulent velocity field in the tank to identify the most dominant energetic modes. The POD analyses of the experimental data in both inlet geometrical configurations were compared with LES simulations. Detailed POD analyses are presented to highlight the impact of geometry on the velocity and thermal fields. These can be correlated with experimental and numerical data to assess the impact of thermal striping on the design of the upper plenum of sodium-cooled nuclear reactors. ALCF.

  2. A-site ordering and stripe phases in manganite films

    Energy Technology Data Exchange (ETDEWEB)

    Sudheendra, L. [Universitaet Goettingen (Germany); Moshnyaga, V. [Universitaet Goettingen (Germany)], E-mail: vmosnea@gwdg.de; Lebedev, O.I. [EMAT, University of Antwerp (Belgium); Gehrke, K. [Universitaet Goettingen (Germany); Belenciuc, A.; Shapoval, O. [Institute of Applied Physics, ASM (Moldova, Republic of); Tendeloo, G. van [EMAT, University of Antwerp (Belgium); Samwer, K. [Universitaet Goettingen (Germany)

    2008-04-01

    Insulating and metallic stripes above and below the Curie temperature, T{sub C}, respectively, were observed by a high-resolution scanning tunneling microscopy (STM) and/or spectroscopy (STS) in A-site ordered and macroscopically strain free epitaxial La{sub 0.75}Ca{sub 0.25}MnO{sub 3} film grown on MgO substrate. The 'insulating' stripes were found to be incommensurable to the lattice and aligned along (1 1 0) direction. Metallic stripes were commensurable with periodicity 2a{sub p}{approx}0.8 nm and aligned parallel to the crystallographic a/b-axis. Formation of these stripes involves competing charge, orbital, and lattice orders and is an outcome of an overlapping of electron wave functions mediated by the local lattice-strain distribution, existed even in A-site ordered film due to the difference in cation radii of La and Ca.

  3. Barley stripe mosaic virus: Structure and relationship to the tobamoviruses

    International Nuclear Information System (INIS)

    Barley stripe mosaic virus (BSMV) is the type member of the genus Hordeivirus, rigid, rod-shaped viruses in the family Virgaviridae. We have used fiber diffraction and cryo-electron microscopy to determine the helical symmetry of BSMV to be 23.2 subunits per turn of the viral helix, and to obtain a low-resolution model of the virus by helical reconstruction methods. Features in the model support a structural relationship between the coat proteins of the hordeiviruses and the tobamoviruses. - Highlights: • We report a low-resolution structure of barley stripe mosaic virus. • Barley stripe mosaic virus has 23.2 subunits per turn of the viral helix. • We compare barley stripe mosaic virus with tobacco mosaic virus

  4. Minimum mean square error method for stripe nonuniformity correction

    Institute of Scientific and Technical Information of China (English)

    Weixian Qian; Qian Chen; Guohua Gu

    2011-01-01

    @@ Stripe nonuniformity is very typical in line infrared focal plane (IRFPA) and uncooled starring IRFPA.We develop the minimum mean square error (MMSE) method for stripe nonuniformity correction (NUC).The goal of the MMSE method is to determine the optimal NUC parameters for making the corrected image the closest to the ideal image.%Stripe nonuniformity is very typical in line infrared focal plane (IRFPA) and uncooled starring IRFPA.We develop the minimum mean square error (MMSE) method for stripe nonuniformity correction (NUC).The goal of the MMSE method is to determine the optimal NUC parameters for making the corrected image the closest to the ideal image. Moreover, this method can be achieved in one frame, making it more competitive than other scene-based NUC algorithms. We also demonstrate the calibration results of our algorithm using real and virtual infrared image sequences. The experiments verify the positive effect of our algorithm.

  5. Curcurbita pepo subspecies delineates striped cucumber beetle (Acalymma vittatum) preference

    Science.gov (United States)

    Brzozowski, L; Leckie, B M; Gardner, J; Hoffmann, M P; Mazourek, M

    2016-01-01

    The striped cucumber beetle (Acalymma vittatum (F.)) is a destructive pest of cucurbit crops, and management could be improved by host plant resistance, especially in organic farming systems. However, despite the variation in striped cucumber beetle preference observed within the economically important species, Cucurbita pepo L., plant breeders and entomologists lacked a simple framework to classify and exploit these differences. This study used recent phylogenetic evidence and bioassays to organize striped cucumber beetle preference within C. pepo. Our results indicate preference contrasts between the two agriculturally relevant subspecies: C. pepo subsp. texana and C. pepo subsp. pepo. Plants of C. pepo subsp. pepo were more strongly preferred than C. pepo subsp. texana plants. This structure of beetle preference in C. pepo will allow plant breeders and entomologists to better focus research efforts on host plant non-preference to control striped cucumber beetles. PMID:27347423

  6. Online identification guides for Australian smut fungi (Ustilaginomycotina) and rust fungi (Pucciniales)

    OpenAIRE

    Shivas, Roger G.; Beasley, Dean R.; McTaggart, Alistair R.

    2014-01-01

    Interactive identification keys for Australian smut fungi (Ustilaginomycotina and Pucciniomycotina, Microbotryales) and rust fungi (Pucciniomycotina, Pucciniales) are available online at http://collections.daff.qld.gov.au. The keys were built using Lucid software, and facilitate the identification of all known Australian smut fungi (317 species in 37 genera) and 100 rust fungi (from approximately 360 species in 37 genera). The smut and rust keys are illustrated with over 1,600 and 570 images ...

  7. Associated callus culture technique for in vitro growth of rust fungi

    OpenAIRE

    A.A. Kuvalekar; Gandhe, K. R.

    2010-01-01

    Uromyces hobsoni, a rust fungus, infects Jasminum officinale var. grandiflorum. The infection frequently leads to malformations in tissues, mainly leaves and stems. Disease progression can be assessed morphologically by observing the extent of malformation and occurrence of sporulation. The rust fungi, in general, are obligate parasites, and need a living host to complete their life cycle. The difficulty of in vitro propagation of rust fungi has been a major obstacle in their detailed bioc...

  8. WRR4, a broad-spectrum TIR-NB-LRR gene from Arabidopsis thaliana that confers white rust resistance in transgenic oilseed Brassica crops.

    Science.gov (United States)

    Borhan, Mohammad Hossein; Holub, Eric B; Kindrachuk, Colin; Omidi, Mansour; Bozorgmanesh-Frad, Ghazaleh; Rimmer, S Roger

    2010-03-01

    White blister rust caused by Albugo candida (Pers.) Kuntze is a common and often devastating disease of oilseed and vegetable brassica crops worldwide. Physiological races of the parasite have been described, including races 2, 7 and 9 from Brassica juncea, B. rapa and B. oleracea, respectively, and race 4 from Capsella bursa-pastoris (the type host). A gene named WRR4 has been characterized recently from polygenic resistance in the wild brassica relative Arabidopsis thaliana (accession Columbia) that confers broad-spectrum white rust resistance (WRR) to all four of the above Al. candida races. This gene encodes a TIR-NB-LRR (Toll-like/interleukin-1 receptor-nucleotide binding-leucine-rich repeat) protein which, as with other known functional members in this subclass of intracellular receptor-like proteins, requires the expression of the lipase-like defence regulator, enhanced disease susceptibility 1 (EDS1). Thus, we used RNA interference-mediated suppression of EDS1 in a white rust-resistant breeding line of B. napus (transformed with a construct designed from the A. thaliana EDS1 gene) to determine whether defence signalling via EDS1 is functionally intact in this oilseed brassica. The eds1-suppressed lines were fully susceptible following inoculation with either race 2 or 7 isolates of Al. candida. We then transformed white rust-susceptible cultivars of B. juncea (susceptible to race 2) and B. napus (susceptible to race 7) with the WRR4 gene from A. thaliana. The WRR4-transformed lines were resistant to the corresponding Al. candida race for each host species. The combined data indicate that WRR4 could potentially provide a novel source of white rust resistance in oilseed and vegetable brassica crops.

  9. Changing the Game: Using Integrative Genomics to Probe Virulence Mechanisms of the Stem Rust Pathogen Puccinia graminis f. sp. tritici.

    Science.gov (United States)

    Figueroa, Melania; Upadhyaya, Narayana M; Sperschneider, Jana; Park, Robert F; Szabo, Les J; Steffenson, Brian; Ellis, Jeff G; Dodds, Peter N

    2016-01-01

    The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt) poses a threat to food security. These concerns have catalyzed an extensive global effort toward controlling this disease. Substantial research and breeding programs target the identification and introduction of new stem rust resistance (Sr) genes in cultivars for genetic protection against the disease. Such resistance genes typically encode immune receptor proteins that recognize specific components of the pathogen, known as avirulence (Avr) proteins. A significant drawback to deploying cultivars with single Sr genes is that they are often overcome by evolution of the pathogen to escape recognition through alterations in Avr genes. Thus, a key element in achieving durable rust control is the deployment of multiple effective Sr genes in combination, either through conventional breeding or transgenic approaches, to minimize the risk of resistance breakdown. In this situation, evolution of pathogen virulence would require changes in multiple Avr genes in order to bypass recognition. However, choosing the optimal Sr gene combinations to deploy is a challenge that requires detailed knowledge of the pathogen Avr genes with which they interact and the virulence phenotypes of Pgt existing in nature. Identifying specific Avr genes from Pgt will provide screening tools to enhance pathogen virulence monitoring, assess heterozygosity and propensity for mutation in pathogen populations, and confirm individual Sr gene functions in crop varieties carrying multiple effective resistance genes. Toward this goal, much progress has been made in assembling a high quality reference genome sequence for Pgt, as well as a Pan-genome encompassing variation between multiple field isolates with diverse virulence spectra. In turn this has allowed prediction of Pgt effector gene candidates based on known features of Avr genes in other plant pathogens, including the related flax rust

  10. Changing the game: using integrative genomics to probe virulence mechanisms of the stem rust pathogen Puccinia graminis f. sp. tritici

    Directory of Open Access Journals (Sweden)

    Melania eFigueroa

    2016-02-01

    Full Text Available The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt poses a threat to food security. These concerns have catalyzed an extensive global effort towards controlling this disease. Substantial research and breeding programs target the identification and introduction of new stem rust resistance (Sr genes in cultivars for genetic protection against the disease. Such resistance genes typically encode immune receptor proteins that recognize specific components of the pathogen, known as avirulence (Avr proteins. A significant drawback to deploying cultivars with single Sr genes is that they are often overcome by evolution of the pathogen to escape recognition through alterations in Avr genes. Thus, a key element in achieving durable rust control is the deployment of multiple effective Sr genes in combination, either through conventional breeding or transgenic approaches, to minimize the risk of resistance breakdown. In this situation, evolution of pathogen virulence would require simultaneous changes in multiple Avr genes in order to bypass recognition. However, choosing the optimal Sr gene combinations to deploy is a challenge that requires detailed knowledge of the pathogen Avr genes with which they interact and the virulence phenotypes of Pgt existing in nature. Identifying specific Avr genes from Pgt will provide screening tools to enhance pathogen virulence monitoring, assess heterozygosity and propensity for mutation in pathogen populations, and confirm individual Sr gene functions in crop varieties carrying multiple effective resistance genes. Towards this goal, much progress has been made in assembling a high quality reference genome sequence for Pgt, as well as a Pan-genome encompassing variation between multiple field isolates with diverse virulence spectra. In turn this has allowed prediction of Pgt effector gene candidates based on known features of Avr genes in other plant pathogens

  11. SFIO a striped file I/O library for MPI

    OpenAIRE

    Gabrielyan, Emin; Hersch, R. D.

    2001-01-01

    This paper presents the design and evaluation of a Striped File I/O (SFIO) library for parallel I/O within an MPI environment. We present techniques for optimizing communications and disk accesses for small striping factors. Using MPI derived datatype capabilities, we transmit fragmented data over the network by single MPI transfers. We present the I/O performance of the SFIO library on DEC Alpha clusters, both for the Fast Ethernet and for the TNET communication networks.

  12. Inhibitive Performance of a Rust Converter on Corrosion of Mild Steel

    Science.gov (United States)

    Zhao, X. D.; Cheng, Y. F.; Fan, W.; Vladimir, C.; Volha, V.; Alla, T.

    2014-11-01

    In this work, a rust converter consisting of two steps of processing solutions was prepared to convert iron rust of the steel surface into a protective conversion film. The performance of the converter was evaluated in both neutral and acidic solutions by various electrochemical measurements, including potentiodynamic polarization curves and electrochemical impedance spectroscopy, and surface characterization. The effect of temperature was investigated. It was found that the rust converter is able to effectively convert the iron rust into a conversion film, serving as a barrier layer to block corrosive species from reaching the steel surface.

  13. Rust fungi on some poaceous weeds of wheat crops in Pakistan

    Directory of Open Access Journals (Sweden)

    NAJAM-UL-SEHAR AFSHAN*

    2013-12-01

    Full Text Available The article enlists common poaceous weeds found in wheat crop sand their specific parasitic rust fungi. In this study, four (04 plant taxa of Poaceae infected with rust fungi are collected from different wheat crops grown in different areas of Pakistan. The rust fungi are isolated, characterized and identified. All these host plants are known weeds of wheat crop in Pakistan. This work would help to identify and enlist the potential rust fungi on weeds of wheat crop that could be utilized to control these noxious weeds in future.

  14. Taxonomy of mayapple rust: the genus Allodus resurrected.

    Science.gov (United States)

    Minnis, Andrew M; McTaggart, Alistair R; Rossman, Amy Y; Aime, M Catherine

    2012-01-01

    Mayapple rust is a common, disfiguring disease that is widespread in temperate eastern North America wherever the host, Podophyllum peltatum, occurs. Puccinia podophylli, the etiological agent of this rust, has been shown to be distantly related to both Puccinia and Uromyces as exemplified by their types. A systematic study was made to determine the generic classification of P. podophylli. Phylogenetic analyses of two rDNA loci from multiple specimens support the recognition of this taxon as a separate genus of Pucciniaceae. Based on historical literature and type material, P. podophylli was found to represent the type of the forgotten genus Allodus and it is correctly named Allodus podophylli. A neotype is designated for Puccinia podophylli Schwein. (≡ Allodus podophylli) and a lectotype is designated for Aecidium podophylli. PMID:22495446

  15. Studies on general resistance to stem rust in wheat

    International Nuclear Information System (INIS)

    Eight cultivars that were thought to have field resistance to stem rust were selected and crossed to produce four four-cultivar hybrids. From those crosses lines were produced that lacked seedling resistance to race 15B-1 of stem rust but had good field resistance to it. They also proved to have field resistance to many other races and it is hoped that the resistance is general. Genetic studies indicated that there is some variation in the lines, but resistance is generally inherited as a quantitative character with several largely recessive genes having small additive effects. This suggests that in an induced mutation programme, no one plant is likely to accumulate sufficient mutant genes that it will appear resistant. (author)

  16. Resistance of European winter wheat germplasm to leaf rust

    OpenAIRE

    Winzeler, Michael; Mesterházy, Ákos; Park, Robert

    2000-01-01

    International audience Seventy two wheat cultivars and breeding lines were tested for at least two years in up to ten European countries for resistance against leaf rust under field conditions. In addition, seedling resistance was determined with local races and with defined isolates to postulate resistance genes. Nine entries (Batis, Capo, RE9001, RE9801, Terza, Toronit, Titlis, Barra, Beaufort) were highly resistant at all locations, and were regarded as excellent sources of resistance f...

  17. Bioprospecting endophytic bacteria for biological control of coffee leaf rust

    OpenAIRE

    Shiomi Humberto Franco; Silva Harllen Sandro Alves; Melo Itamar Soares de; Nunes Flávia Vieira; Bettiol Wagner

    2006-01-01

    Suppression of plant diseases due to the action of endophytic microorganisms has been demonstrated in several pathosystems. Experiments under controlled conditions involving endophytic bacteria isolated from leaves and branches of Coffea arabica L and Coffea robusta L were conducted with the objective of evaluating the inhibition of germination of Hemileia vastatrix Berk. & Br., race II, urediniospores and the control of coffee leaf rust development in tests with leaf discs, detached leaves, ...

  18. The past, present and future of breeding rust resistant wheat.

    Science.gov (United States)

    Ellis, Jeffrey G; Lagudah, Evans S; Spielmeyer, Wolfgang; Dodds, Peter N

    2014-01-01

    Two classes of genes are used for breeding rust resistant wheat. The first class, called R (for resistance) genes, are pathogen race specific in their action, effective at all plant growth stages and probably mostly encode immune receptors of the nucleotide binding leucine rich repeat (NB-LRR) class. The second class is called adult plant resistance genes (APR) because resistance is usually functional only in adult plants, and, in contrast to most R genes, the levels of resistance conferred by single APR genes are only partial and allow considerable disease development. Some but not all APR genes provide resistance to all isolates of a rust pathogen species and a subclass of these provides resistance to several fungal pathogen species. Initial indications are that APR genes encode a more heterogeneous range of proteins than R proteins. Two APR genes, Lr34 and Yr36, have been cloned from wheat and their products are an ABC transporter and a protein kinase, respectively. Lr34 and Sr2 have provided long lasting and widely used (durable) partial resistance and are mainly used in conjunction with other R and APR genes to obtain adequate rust resistance. We caution that some APR genes indeed include race specific, weak R genes which may be of the NB-LRR class. A research priority to better inform rust resistance breeding is to characterize further APR genes in wheat and to understand how they function and how they interact when multiple APR and R genes are stacked in a single genotype by conventional and GM breeding. An important message is do not be complacent about the general durability of all APR genes.

  19. The past, present and future of breeding rust resistant wheat

    Directory of Open Access Journals (Sweden)

    Jeffrey G Ellis

    2014-11-01

    Full Text Available Two classes of genes are used for breeding rust resistant wheat. The first class, called R (for resistance genes, are pathogen race-specific in their action, effective at all plant growth stages and probably mostly encode immune receptors of the nucleotide binding leucine rich repeat (NB-LRR class. The second class called Adult Plant Resistance genes (APR because resistance is usually functional only in adult plants, and, in contrast to most R genes, the levels of resistance conferred by single APR genes are only partial and allow considerable disease development. Some but not all APR genes provide resistance to all isolates of a rust pathogen species and a subclass of these provides resistance to several fungal pathogen species. Initial indications are that APR genes encode a more heterogeneous range of proteins than R proteins. Two APR genes, Lr34 and Yr36, have been cloned from wheat and their products are an ABC transporter and a protein kinase, respectively. Lr34 and Sr2 have provided long lasting and widely used (durable partial resistance and are mainly used in conjunction with other R and APR genes to obtain adequate rust resistance. We caution that some APR genes indeed include race-specific, weak R genes which may be of the NB-LRR class. A research priority to better inform rust resistance breeding is to characterize further APR genes in wheat and to understand how they function and how they interact when multiple APR and R genes are stacked in a single genotype by conventional and GM breeding. An important message is do not be complacent about the general durability of all APR genes.

  20. Resistance of alloplasmic wheats to brown leaf rust

    Directory of Open Access Journals (Sweden)

    Alexander Lvovivh SECHNYAK

    2010-11-01

    Full Text Available The reaction of alloplasmic and euplasmic lines of wheat on brown leaf rust was studied in the condition of field infectious nursery in 2002, 2004, 2006 and 2007. The influence of cytoplasmic genome on resistance of the investigated lines varied for years and probably was mainly specific to race. However the positive effect of alloplasm from Aegilops squarrosa var. typica on resistance to pathogene was stable and universal.

  1. A pigeonpea gene confers resistance to Asian soybean rust in soybean.

    Science.gov (United States)

    Kawashima, Cintia G; Guimarães, Gustavo Augusto; Nogueira, Sônia Regina; MacLean, Dan; Cook, Doug R; Steuernagel, Burkhard; Baek, Jongmin; Bouyioukos, Costas; Melo, Bernardo do V A; Tristão, Gustavo; de Oliveira, Jamile Camargos; Rauscher, Gilda; Mittal, Shipra; Panichelli, Lisa; Bacot, Karen; Johnson, Ebony; Iyer, Geeta; Tabor, Girma; Wulff, Brande B H; Ward, Eric; Rairdan, Gregory J; Broglie, Karen E; Wu, Gusui; van Esse, H Peter; Jones, Jonathan D G; Brommonschenkel, Sérgio H

    2016-06-01

    Asian soybean rust (ASR), caused by the fungus Phakopsora pachyrhizi, is one of the most economically important crop diseases, but is only treatable with fungicides, which are becoming less effective owing to the emergence of fungicide resistance. There are no commercial soybean cultivars with durable resistance to P. pachyrhizi, and although soybean resistance loci have been mapped, no resistance genes have been cloned. We report the cloning of a P. pachyrhizi resistance gene CcRpp1 (Cajanus cajan Resistance against Phakopsora pachyrhizi 1) from pigeonpea (Cajanus cajan) and show that CcRpp1 confers full resistance to P. pachyrhizi in soybean. Our findings show that legume species related to soybean such as pigeonpea, cowpea, common bean and others could provide a valuable and diverse pool of resistance traits for crop improvement. PMID:27111723

  2. 金属零部件防锈包装技术介绍%Metal Parts Rust-proof Packaging Technology Introd-u ction

    Institute of Scientific and Technical Information of China (English)

    张晓刚

    2014-01-01

    This article describes the great loss in equipment manufacturing industry caused by corrosion and elaborates three rust-proof technologies .%本文介绍了因锈蚀问题给装备制造各行业带来了巨大的损失,了解防锈技术就变得重要起来,针对三种防锈技术进行了阐述。

  3. Individual-based model of young-of-the-year striped bass population dynamics. II. Factors affecting recruitment in the Potomac River, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, J.H. (Univ. of South Alabama, Mobile, AL (United States)); Rose, K.A. (Oak Ridge National Lab., TN (United States)); Rutherford, E.S.; Houde, E.D. (Univ. of Maryland System, Solomons, MD (United States))

    1993-05-01

    An individual-based model of the population dynamics of young-of-the-year striped bass Morone saxatilis in the Potomac River, Maryland, was used to test the hypothesis that historically high recruitment variability can be explained by changes in environmental and biological factors that result in relatively small changes in growth and mortality rates of striped bass larvae. The four factors examined were (1) size distribution of female parents, (2) zooplankton prey density during the development of striped bass larvae, (3) density of completing larval white perch M. americana, and (4) temperature during larval development. Simulation results suggest that variations in female size and in prey for larvae alone could cause 10-fold variability in recruitment. But no single factor alone caused changes in vital rates of age-0 fish that could account for the 145-fold variability in the Potomac River index of juvenile recruitment. However, combined positive or negative effects of two or more factors resulted in more than a 150-fold simulated recruitment variability, suggesting that combinations of factors can account for the high observed annual variability in striped bass recruitment success. Higher cumulative mortality of feeding larvae and younger life stages than of juveniles was common to all simulations. supporting the contention that striped bass year-class strength is determined prior to metamorphosis. 76 refs., 7 figs., 4 tabs.

  4. Evaluation of fatigue damage induced by thermal striping in a T junction using the three dimensional coupling method and frequency response method

    International Nuclear Information System (INIS)

    Thermal fatigue cracking induced by thermal stratification, cycling and striping have been observed in several PWR plants. Especially, thermal striping, the highly fluctuating thermal layer, became one of the significant problems, since it can cause un predicted high cycle thermal fatigue (HCTF) at piping systems. This problem are usually found in T junctions of energy cooling systems, where cold and hot flows with high level of turbulence mix together. Thermal striping can cause the networks of fatigue crack at the vicinity of weld parts and these cracks can propagate to significant depth in a relatively short time. Therefore, thermal striping and fatigue crack initiations should be predicted in advance to prevent the severe failure of piping systems. The final goal of this research is to develop a rational thermal and mechanical model considering thermohydraulic characteristics of thermal striping and an evaluation procedure to predict the initiation of thermal fatigue crack. As a first step, we evaluated the fatigue damage in a T junction using two widely used methods. Then, we analyzed the results of each method and conducted comparisons and verifications

  5. A perspective of leaf rust race fhprn and its impact on leaf rust resistance in pakistani wheat varieties

    International Nuclear Information System (INIS)

    Leaf rust infected leaves of a widely growing variety Seher-06 were collected in wheat season of 2011-12. The leaf rust isolates were assessed on Thatcher derived Lr isogenic lines and a race FHPRN was identified. Seventy six wheat varieties/lines besides Lr isogenic lines were screened against this race for seedling in glass house and for adult plant resistance at Bahawalpur and Faisalabad during 2012-13. Lr1, Lr2a, Lr9, Lr19, Lr24, Lr10+27+31 (Gatcher) and Lr28 were found completely resistant at both stages against FHPRN. Molecular screening of the wheat varieties/lines indicated the presence of leaf rust resistance genes Lr9 (0%), Lr13 (43%), Lr19 (1%), Lr20 (0%), Lr24 (4%), Lr26 (23%), Lr28 (0%), Lr34 (38%), Lr37 (1%) and Lr47 (1%) in them. Field data suggested that As-02 (Lr10+26+34), Bhakar-02 (Lr13) and Shafaq-06 (Lr10+13+27) were resistant; Pasban-90 (Lr10+13+26+27), Chenab-2000 (Lr10+13+26+27+31+34), Fbd-08 (Lr10), Millat-11 (unknown) and Punjab-11 (unknown) were found moderately resistant; Blue silver (Lr13+14a), Pak-81 (Lr10+23+26+31), Bahawalpur-97 (Lr13+26) and Lasani-08 (Lr13+27+31) were susceptible while Sh-88 (unknown), Auqab-2000 (Lr10+23+26+27+31), Iqbal-2000 (Lr3+10+13+26+27+31), Bahawalpur-2000 (Lr34) and Seher-06 (Lr10+27+31) were found highly susceptible against FHPRN. Present and previous studies revealed the presence of Lr3, 10, 13, 14a, 23, 26, 27, 31 and 34 in the Pakistani wheat varieties yet lacking Lr9, 19, 24 and 28. Therefore, the latter genes and their effective combinations should be incorporated in Pakistani varieties to combat leaf rust effectively. (author)

  6. Gene expression patterns of wheat rust resistance gene Lr34/Yr18 indicate novel mode of action

    Science.gov (United States)

    The Lr34/Yr18 resistance gene provides durable, adult-plant, slow-rusting resistance to leaf rust and yellow rust of wheat. Patterns of gene expression were examined by microarray analysis in inoculated and mock-inoculated flag leaves of two pairs of near isogenic lines for Lr34/Yr18 (Thatcher/Thatc...

  7. Postulation of seedling leaf rust resistance genes in 84 Chinese winter wheat cultivars

    Institute of Scientific and Technical Information of China (English)

    REN Xiao-li; LIU Tai-guo; LIU Bo; GAO Li; CHEN Wan-quan

    2015-01-01

    Wheat leaf rust (caused byPuccinia triticina) is one of the most important fungal diseases in China. There are tens of winter wheat cultivars which are approved to be released by the government at a national level and more than 100 wheat cultivars at the provincial level. But there is no information about leaf rust (Lr) genes in these cultivars, which makes it dififcult for farmers and breeders to select which cultivars they should plant in their ifelds and use in their breeding programs. The objec-tive of this paper was to identify the leaf rust resistant genes at seedling stage present in the 84 commercial wheat cultivars from China that have been released in the past few years. A set of 20 near isogenic lines with Thatcher background and 6 lines with knownLr genes were used to test the virulence of 12 races ofP. triticina (Pt). By comparing the infection types (ITs) produced on the 84 cultivars by the 12Pt races with the ITs on the differential sets, theLrgenes were postulated. In addition, 8 molecular markers ofLr genes such asLr9,Lr10,Lr19,Lr20,Lr21,Lr24,Lr26 andLr29, which are closely linked to or co-segregated with theLr gene, were used for further validation of the genes in the 84 Chinese winter wheat cultivars. TwelveLr genes, includingLr1, Lr3,(Lr3bg), (Lr3ka), Lr11, Lr13, Lr14a, Lr16, Lr26, Lr27, Lr30 andLr31 were postulated to be present either singly or in combinations in these Chinese wheat cultivars.Lr3 andLr26 were detected most often in the tested cultivars, with frequencies of 51.2 and 38.1%, respectively. No wheatLr genes were detected in 16 cultivars, and 4 cultivars may carry unknownLr genes other than those used in this study.Lr9,Lr20,Lr21,Lr24,Lr25andLr29 were not present in any of the 84 tested accessions.

  8. Dynamical Layer Decoupling in a Stripe-ordered, High T_c Superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Berg, E.

    2010-04-06

    In the stripe-ordered state of a strongly-correlated two-dimensional electronic system, under a set of special circumstances, the superconducting condensate, like the magnetic order, can occur at a non-zero wave-vector corresponding to a spatial period double that of the charge order. In this case, the Josephson coupling between near neighbor planes, especially in a crystal with the special structure of La{sub 2-x}Ba{sub x}CuO{sub 4}, vanishes identically. We propose that this is the underlying cause of the dynamical decoupling of the layers recently observed in transport measurements at x = 1/8.

  9. Epistatic adult plant resistance in wheat to stem rust cosegregates with Sr12 seedling resistance

    Science.gov (United States)

    Wheat adult plant resistance (APR) to stem rust is desirable. Researchers have characterized the inheritance of APR in cultivar Thatcher as complex. In order to identify the loci providing APR in Thatcher, we evaluated 160 RILs derived from Thatcher/McNeal for stem rust reaction in the field in Keny...

  10. Morphology and AFLP markers suggest three Hordeum chilense ecotypes that differ in avoidance to rust fungi

    NARCIS (Netherlands)

    Vaz Patto, M.C.; Aardse, A.; Buntjer, J.; Rubiales, D.; Martin, A.; Niks, R.E.

    2001-01-01

    In Hordeum chilense Roem. & Schult., a high variation in the level of avoidance to infection of barley leaf rust (Puccinia hordei Otth) occurs. Probably resulting from the properties of the stomata, the rust germ tube overgrows stomata, and the infection process fails in an early stage. In the prese

  11. An accurate DNA marker assay for stem rust resistance gene Sr2 in wheat

    Science.gov (United States)

    The stem rust resistance gene Sr2 has provided broad-spectrum protection against stem rust (Puccinia graminis) since its wide spread deployment in wheat from the 1940s. Because Sr2 confers partial resistance which is difficult to select under field conditions, a DNA marker is desirable that accurate...

  12. Rusting Evolution of MnCuP Weathering Steel Submitted to Simulated Industrial Atmospheric Corrosion

    Science.gov (United States)

    Hao, Long; Zhang, Sixun; Dong, Junhua; Ke, Wei

    2012-05-01

    The rusting evolution of MnCuP weathering steel in a simulated industrial atmosphere as a function of corrosion duration was investigated by corrosion weight gain, scanning electron microscopy, X-ray diffraction, and electrochemical methods. The results indicate that the corrosion kinetics is related closely to the rust composition and electrochemical properties. The corrosion rate is higher during the first corrosion stage, and it is lower during the second corrosion stage. During the first corrosion stage, the rust layer is in low density, discontinuous, and loose, with a lower relative abundance of α-FeOOH. During the second corrosion stage, a compact and protective inner rust layer forms with a higher relative abundance of α-FeOOH, contributing to enhanced rust layer resistance. The rust initially enhances and then stabilizes the cathodic process, but the anodic process tends to be inhibited by the protective rust layer. Electrochemical impedance spectroscopy tests indicate that it is more scientific to evaluate the rust layer protective ability by charge transfer resistance.

  13. Molecular tagging of a novel rust resistance gene R12 in sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Sunflower production in North America has recently suffered economic losses in yield and seed quality from sunflower rust (Puccinia helianthi Schwein.) because of the increasing incidence and lack of resistance to new rust races. RHA 464, a newly released sunflower male fertility restorer line, is r...

  14. Cell orientation on a stripe-micropatterned surface

    Institute of Scientific and Technical Information of China (English)

    SUN JianGuo; TANG Jian; DING JianDong

    2009-01-01

    Stripe-micropatterned surfaces have recently been a unique tool to study cell orientation. In this paper,we prepared,by the photolithography transfer technique,stable gold (Au) micropatterns on PEG hydrogel surfaces with defined cell-resistant (PEG hydrogel) and cell-adhesive (gold microstripes) proparties. 3T3 fibroblasts were cultured on Au-microstripe surfaces to observe cell adhesion and orientation. Five statistical parameters were defined and used to describe cell orientation on micropatterns.With the increase of inter-stripe distance,the orientational order parameter,the ratio of long and short axes of a cell,and the occupation fraction of cells on stripes increased gradually,whereas the spreading area of a single cell decreased. The abrupt changes of these four parameters did not happen at the same inter-distance. The adhesion ratio of a cell on Au stripes over cell spreading area did not change monotonically as a function of inter-stripe distance. The combination of the 5 statistical parameters represented well the cell orientation behaviors semi-quantitatively.

  15. Characterization of Rust Layer Formed on Low Alloy Steel Exposed in Marine Atmosphere

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The iron rust phases formed on Iow alloy steels containing different quantities of Cr element have been characterizedusing EPMA, Raman spectroscopy, TEM, optical microscopy etc. The ion selective properties of synthesized rust filmswith the same phase constituent as the atmospheric corrosion products were investigated using self-made apparatus.The results showed that corrosion loss of steels exposed in marine atmosphere decreased rapidly as the Cr contentof the steel was increased. Cr-containing steels were covered by a uniform compacted rust layer composed of fineparticles with an average diameter of several nanometers. Inner rust layer of Cr-containing steel (2 mass fraction)was composed of α-CrxFel-xOOH, with Cr content of about 5 mass fraction. Such rust layer showed cation selectiveproperty, and could depress the penetration of Cl- to contact substrate steel directly.

  16. Associated callus culture technique for in vitro growth of rust fungi

    Directory of Open Access Journals (Sweden)

    A.A. Kuvalekar

    2010-08-01

    Full Text Available Uromyces hobsoni, a rust fungus, infects Jasminum officinale var. grandiflorum. The infection frequently leads to malformations in tissues, mainly leaves and stems. Disease progression can be assessed morphologically by observing the extent of malformation and occurrence of sporulation. The rust fungi, in general, are obligate parasites, and need a living host to complete their life cycle. The difficulty of in vitro propagation of rust fungi has been a major obstacle in their detailed biochemical and molecular analysis. In this paper, we report successful in vitro culture of rust fungi with induction of callus from infected leaves of host plants which contain initial differentiated structures like haustoria and intercellular hyphae. This ‘associated callus culture’ technique has opened new paths for studying host-pathogen interactions of rust fungi.

  17. QTL analysis of crown rust resistance in perennial ryegrass under conditions of natural and artificial infection

    DEFF Research Database (Denmark)

    Schejbel, Britt; Jensen, Louise Friis Bach; Xing, Yongzhong;

    2007-01-01

    Crown rust is an economically devastating disease of perennial ryegrass. Both artificial crown rust inoculations, with the possibility of several selection cycles in one year, as well as marker-assisted selection can be used for more efficient breeding of new resistant cultivars. The objective...... of this study was to map quantitative trait loci (QTL) for response to crown rust infection in perennial ryegrass. In order to identify relevant markers for response to crown rust infection, QTL mapping was performed on a ryegrass mapping population which was evaluated for resistance in the field for two years...... as well as by artificial pathogen inoculations using a detached leaf assessment. The broad sense heritability values for the field, detached leaf and combined assays were 0.42, 0.56, and 0.64, respectively, indicating a good potential for selection for crown rust resistance. A total of six QTLs were...

  18. Chaotic and Arnold stripes in weakly chaotic Hamiltonian systems.

    Science.gov (United States)

    Custódio, M S; Manchein, C; Beims, M W

    2012-06-01

    The dynamics in weakly chaotic Hamiltonian systems strongly depends on initial conditions (ICs) and little can be affirmed about generic behaviors. Using two distinct Hamiltonian systems, namely one particle in an open rectangular billiard and four particles globally coupled on a discrete lattice, we show that in these models, the transition from integrable motion to weak chaos emerges via chaotic stripes as the nonlinear parameter is increased. The stripes represent intervals of initial conditions which generate chaotic trajectories and increase with the nonlinear parameter of the system. In the billiard case, the initial conditions are the injection angles. For higher-dimensional systems and small nonlinearities, the chaotic stripes are the initial condition inside which Arnold diffusion occurs.

  19. Effects of water velocity on activity of juvenile striped bass

    Energy Technology Data Exchange (ETDEWEB)

    Bowles, R.R.; Griffith, J.S.; Coutant, C.C.

    1976-07-01

    The swimming activity of juvenile striped bass (Morone saxatilis Walbaum) 8 to 80 mm long was investigated in a test chamber simulating, on a small scale, a fixed-screen cooling water intake structure. As water velocity increased from 0 to 30 cm/sec area and distance traveled by juvenile bass 10 to 80 mm long decreased. However, as water velocity increased from 0 to 3 cm/sec the area and distance covered by larval bass increased. The presence of food increased the activity of larval bass, but decreased the activity of juveniles. Area ranged by striped bass at test velocities ranging from 0 to 30 cm/sec increased in proportion to body length. Juvenile striped bass tested at acclimation temperatures between 20 and 5/sup 0/C experienced a 30% reduction of activity. Activity was also reduced as temperature increased from 20 to 30/sup 0/C.

  20. Stripes in cuprate superconductors: Excitations and dynamic dichotomy

    Energy Technology Data Exchange (ETDEWEB)

    Seibold, G., E-mail: goetz@physik.tu-cottbus.de [Institut fuer Physik, BTU Cottbus, P.O. Box 101344, 03013 Cottbus (Germany); Grilli, M.; Lorenzana, J. [SMC-INFM-CNR, Dipartimento di Fisica, Universita di Roma ' La Sapienza' , P.le Aldo Moro 5, I-00185 Roma (Italy)

    2012-11-01

    We present a short account of the present experimental situation of stripes in cuprates followed by a review of our present understanding of their ground state and excited state properties. Collective modes, the dynamical structure factor, and the optical conductivity of stripes are computed using the time-dependent Gutzwiller approximation applied to realistic one band and three band Hubbard models, and are found to be in excellent agreement with experiment. On the other hand, experiments like angle-resolved photoemission and scanning tunneling microscopy show the coexistence of stripes at high energies with Fermi liquid quasiparticles at low energies. We show that a phenomenological model going beyond mean-field can reconcile this dynamic dichotomy.

  1. Strong-Coupling and the Stripe Phase of ^3He

    Science.gov (United States)

    Wiman, Joshua J.; Sauls, J. A.

    2016-09-01

    Thin films of superfluid 3He were predicted, based on weak-coupling BCS theory, to have a stable phase which spontaneously breaks translational symmetry in the plane of the film. This crystalline superfluid, or "stripe" phase, develops as a one-dimensional periodic array of domain walls separating degenerate B phase domains. We report calculations of the phases and phase diagram for superfluid 3He in thin films using a strong-coupling Ginzburg-Landau theory that accurately reproduces the bulk 3He superfluid phase diagram. We find that the stability of the Stripe phase is diminished relative to the A phase, but the Stripe phase is stable in a large range of temperatures, pressures, confinement, and surface conditions.

  2. Stable multidimensional soliton stripes in two-component Bose-Einstein condensates

    Energy Technology Data Exchange (ETDEWEB)

    Brazhnyi, Valeriy A. [Centro de Fisica do Porto, Faculdade de Ciencias, Universidade do Porto, R. Campo Alegre 687, Porto 4169-007 (Portugal); Perez-Garcia, Victor M., E-mail: victor.perezgarcia@uclm.es [Departamento de Matematicas, E. T. S. de Ingenieros Industriales, and Instituto de Matematica Aplicada a la Ciencia y la Ingenieria, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

    2011-06-15

    Highlights: > Soliton-stripes (multidimensional extensions of dark solitons) are constructed in multicomponent BECs. > A second component filling the core of the stripe leads to reduced instabilities while propagating in homogeneous media. > In the presence of a trap arbitrarily long-lived stripes can be constructed by increasing the core filling. - Abstract: We discuss how to construct stable multidimensional extensions of one-dimensional dark solitons, the so-called soliton stripes, in two-species Bose-Einstein condensates in the immiscible regime. We show how using a second component to fill the core of a dark soliton stripe leads to reduced instabilities while propagating in homogeneous media. We also discuss how in the presence of a trap arbitrarily long-lived dark soliton stripes can be constructed by increasing the filling of the dark stripe core. Numerical evidences of the robustness of the dark soliton stripes in collision scenarios are also provided.

  3. Color-Stripe Structured Light Robust to Surface Color and Discontinuity

    CERN Document Server

    Lee, Kwang Hee; Lee, Sang Wook

    2015-01-01

    Multiple color stripes have been employed for structured light-based rapid range imaging to increase the number of uniquely identifiable stripes. The use of multiple color stripes poses two problems: (1) object surface color may disturb the stripe color and (2) the number of adjacent stripes required for identifying a stripe may not be maintained near surface discontinuities such as occluding boundaries. In this paper, we present methods to alleviate those problems. Log-gradient filters are employed to reduce the influence of object colors, and color stripes in two and three directions are used to increase the chance of identifying correct stripes near surface discontinuities. Experimental results demonstrate the effectiveness of our methods.

  4. Laser light stripe measurements assure correct piston assembly

    Science.gov (United States)

    Stein, Norbert; Frohn, Heiko

    1993-12-01

    Two VIKON-3D optical inspection systems assure the correct assembly of piston rings and guard rings in a new Volkswagen piston/rod assembly line. Both systems use laser light stripe measurements to locate and identify the relevant parts with high accuracy. The piston ring assembly is checked dynamically in video real time using laser light stripe and parallel projection techniques. In addition structured light is used to verify the correct piston/rod assembly. Both inspection systems are fully integrated into the manufacturing line. All types of pistons assembled can be checked without any mechanical changes to the measurement setup.

  5. Distinguishing Patterns of Charge Order: Stripes or Checkerboards

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, J.A.

    2010-04-06

    In two dimensions, quenched disorder always rounds transitions involving the breaking of spatial symmetries so, in practice, it can often be difficult to infer what form the symmetry breaking would take in the 'ideal,' zero disorder limit. We discuss methods of data analysis which can be useful for making such inferences, and apply them to the problem of determining whether the preferred order in the cuprates is 'stripes' or 'checkerboards.' In many cases we show that the experiments clearly indicate stripe order, while in others (where the observed correlation length is short), the answer is presently uncertain.

  6. Assessing Wheat Yellow Rust Disease through Hyperspectral Remote Sensing

    Science.gov (United States)

    Krishna, G.; Sahoo, R. N.; Pargal, S.; Gupta, V. K.; Sinha, P.; Bhagat, S.; Saharan, M. S.; Singh, R.; Chattopadhyay, C.

    2014-12-01

    The potential of hyperspectral reflectance data was explored to assess severity of yellow rust disease (Biotroph Pucciniastriiformis) of winter wheat in the present study. The hyperspectral remote sensing data was collected for winter wheat (Triticum aestivum L.) cropat different levels of disease infestation using field spectroradiometer over the spectral range of 350 to 2500 nm. The partial least squares (PLS) and multiple linear (MLR) regression techniques were used to identify suitable bands and develop spectral models for assessing severity of yellow rust disease in winter wheat crop. The PLS model based on the full spectral range and n = 36, yielded a coefficient of determination (R2) of 0.96, a standard error of cross validation (SECV) of 12.74 and a root mean square error of cross validation (RMSECV) of 12.41. The validation analysis of this PLS model yielded r2 as 0.93 with a SEP (Standard Error of Prediction) of 7.80 and a RMSEP (Root Mean Square Error of prediction) of 7.46. The loading weights of latent variables from PLS model were used to identify sensitive wavelengths. To assess their suitability multiple linear regression (MLR) model was applied on these wavelengths which resulted in a MLR model with three identified wavelength bands (428 nm, 672 nm and 1399 nm). MLR model yielded acceptable results in the form of r2 as 0.89 for calibration and 0.90 for validation with SEP of 3.90 and RMSEP of 3.70. The result showed that the developed model had a great potential for precise delineation and detection of yellow rust disease in winter wheat crop.

  7. Screening and incorporation of rust resistance from Allium cepa into bunching onion (Allium fistulosum) via alien chromosome addition.

    Science.gov (United States)

    Wako, Tadayuki; Yamashita, Ken-ichiro; Tsukazaki, Hikaru; Ohara, Takayoshi; Kojima, Akio; Yaguchi, Shigenori; Shimazaki, Satoshi; Midorikawa, Naoko; Sakai, Takako; Yamauchi, Naoki; Shigyo, Masayoshi

    2015-04-01

    Bunching onion (Allium fistulosum L.; 2n = 16), bulb onion (Allium cepa L. Common onion group), and shallot (Allium cepa L. Aggregatum group) cultivars were inoculated with rust fungus, Puccinia allii, isolated from bunching onion. Bulb onions and shallots are highly resistant to rust, suggesting they would serve as useful resources for breeding rust resistant bunching onions. To identify the A. cepa chromosome(s) related to rust resistance, a complete set of eight A. fistulosum - shallot monosomic alien addition lines (MAALs) were inoculated with P. allii. At the seedling stage, FF+1A showed a high level of resistance in controlled-environment experiments, suggesting that the genes related to rust resistance could be located on shallot chromosome 1A. While MAAL, multi-chromosome addition line, and hypoallotriploid adult plants did not exhibit strong resistance to rust. In contrast to the high resistance of shallot, the addition line FF+1A+5A showed reproducibly high levels of rust resistance.

  8. Effect of Phosphate on the Oxidation of Hydroxysulfate Green Rust

    Science.gov (United States)

    Benali, Omar; Abdelmoula, Mustapha; Génin, Jean.-Marie R.

    2005-04-01

    During Hydroxysulfate green rust GR(SO42) oxidation, lepidocrocite and goethite were formed. The oxidation of GR(SO42-) in the presence of phosphate ions, also involved the formation of poorly crystallized lepidocrocite but not that of goethite. The dissolution of lepidocrocite is inhibited by adsorption of phosphate ions as confirmed by X-ray photoelectron spectroscopy. The formation of the poorly crystallized protective layer against corrosion is effectively due to the phosphate ions which adsorb on the surface of lepidocrocite, and prevents it to turn into a well crystallized oxide.

  9. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  10. Registration of ‘Puma’ soft white winter wheat

    Science.gov (United States)

    Resistance to strawbreaker foot rot (caused by Oculimacula yallundae Crous & W. Gams and O. acuformis Crous & W. Gams), stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici Eriks.), and Cephalosporium stripe (caused by Cephalosporium gramineum Nisikado and Ikata) are important traits ...

  11. Inhibitory Effect of Camptothecin against Rice Bacterial Brown Stripe Pathogen Acidovorax avenae subsp. avenae RS-2.

    Science.gov (United States)

    Dong, Qiaolin; Luo, Ju; Qiu, Wen; Cai, Li; Anjum, Syed Ishtiaq; Li, Bin; Hou, Mingsheng; Xie, Guanlin; Sun, Guochang

    2016-01-01

    Camptothecin (CPT) has anticancer, antiviral, and antifungal properties. However, there is a dearth of information about antibacterial activity of CPT. Therefore, in this study, we investigated the inhibitory effect of CPT on Acidovorax avenae subsp. avenae strain RS-2, the pathogen of rice bacterial brown stripe, by measuring cell growth, DNA damage, cell membrane integrity, the expression of secretion systems, and topoisomerase-related genes, as well as the secretion of effector protein Hcp. Results indicated that CPT solutions at 0.05, 0.25, and 0.50 mg/mL inhibited the growth of strain RS-2 in vitro, while the inhibitory efficiency increased with an increase in CPT concentration, pH, and incubation time. Furthermore, CPT treatment affected bacterial growth and replication by causing membrane damage, which was evidenced by transmission electron microscopic observation and live/dead cell staining. In addition, quantitative real-time PCR analysis indicated that CPT treatment caused differential expression of eight secretion system-related genes and one topoisomerase-related gene, while the up-regulated expression of hcp could be justified by the increased secretion of Hcp based on the ELISA test. Overall, this study indicated that CPT has the potential to control the bacterial brown stripe pathogen of rice. PMID:27472315

  12. The role of green rust in the environment: a review O papel do green rust no ambiente

    Directory of Open Access Journals (Sweden)

    Lucia H. G. Chaves

    2005-06-01

    Full Text Available Iron(II-iron(III hydroxy-salts known as green rusts (GRs initially were identified and studied as corrosion products of steel and iron. Recently they were discovered as minerals present in hydromorphic soils and sediments. Different studies have suggested that GRs, due to their high reactivity, play an important role in the fate and transport of many contaminants in suboxic soils, sediments and aquifers where microbial reduction rates are limited by low carbon content. Also, GRs have considerable potential for applications such as water-purification processes and gas adsorbents. However, as GRs are only a transient state during the reduction of ferric iron and are converted to more stable forms, it is still necessary to continue studies about their behavior.Hidróxidos de ferro (II-ferro(III conhecidos como "green rust" (GR, inicialmente foram identificados e estudados como sendo os produtos provenientes da corrosão do aço e do ferro. Recentemente esses hidróxidos foram encontrados na forma mineral em solos hidromórficos e em sedimentos. Devido a sua alta reatividade, muitos trabalhos têm mostrado que esses hidróxidos desempenham um importante papel no destino e transporte de muitos contaminantes em solos subóxicos, sedimentos e aqüíferos, onde a taxa de redução microbiana é limitada pelo baixo conteúdo de carbono. Os "green rusts" também podem ser utilizados nos processos de purificação de águas e como adsorventes de gases. Entretanto, como GR são considerados uma fase transitória durante a redução do íon férrico e são, rapidamente, convertidos para formas mais estáveis, é necessário que os estudos sobre seu comportamento continuem.

  13. Study of Rust Effect on the Corrosion Behavior of Reinforcement Steel Using Impedance Spectroscopy

    Science.gov (United States)

    Bensabra, Hakim; Azzouz, Noureddine

    2013-12-01

    Most studies on corrosion of steel reinforcement in concrete are conducted on steel samples with polished surface (free of all oxides) in order to reproduce the same experimental conditions. However, before embedding in concrete, the steel bars are often covered with natural oxides (rust), which are formed during exposure to the atmosphere. The presence of this rust may affect the electrochemical behavior of steel rebar in concrete. In order to understand the effect of rust on the corrosion behavior of reinforcement steel, potentiodynamic and electrochemical impedance spectroscopy (EIS) tests were carried out in a simulated concrete pore solution using steel samples with two different surface conditions: polished and rusted samples. The obtained results have shown that the presence of rust on the steel bar has a negative effect on its corrosion behavior, with or without the presence of chlorides. This detrimental effect can be explained by the fact that the rust provokes a decrease of the electrolyte resistance at the metal-concrete interface and reduces the repassivating ability. In addition, the rust layer acts as a barrier against the hydroxyl ion diffusion, which prevents the realkalinization phenomenon.

  14. Introgression of a leaf rust resistance gene from Aegilops caudata to bread wheat

    Indian Academy of Sciences (India)

    Amandeep Kaur Riar; Satinder Kaur; H. S. Dhaliwal; Kuldeep Singh; Parveen Chhuneja

    2012-08-01

    Rusts are the most important biotic constraints limiting wheat productivity worldwide. Deployment of cultivars with broad spectrum rust resistance is the only environmentally viable option to combat these diseases. Identification and introgression of novel sources of resistance is a continuous process to combat the ever evolving pathogens. The germplasm of nonprogenitor Aegilops species with substantial amount of variability has been exploited to a limited extent. In the present investigation introgression, inheritance and molecular mapping of a leaf rust resistance gene of Ae. caudata (CC) acc. pau3556 in cultivated wheat were undertaken. An F2 population derived from the cross of Triticum aestivum cv.WL711 – Ae. caudata introgression line T291-2 with wheat cultivar PBW343 segregated for a single dominant leaf rust resistance gene at the seedling and adult plant stages. Progeny testing in F3 confirmed the introgression of a single gene for leaf rust resistance. Bulked segregant analysis using polymorphic D-genome-specific SSR markers and the cosegregation of the 5DS anchored markers (Xcfd18, Xcfd78, Xfd81 and Xcfd189) with the rust resistance in the F2 population mapped the leaf rust resistance gene (LrAC) on the short arm of wheat chromosome 5D. Genetic complementation and the linked molecular markers revealed that LrAC is a novel homoeoallele of an orthologue Lr57 already introgressed from the 5M chromosome of Ae. geniculata on 5DS of wheat.

  15. A reassessment of the risk of rust fungi developing resistance to fungicides.

    Science.gov (United States)

    Oliver, Richard P

    2014-11-01

    Rust fungi are major pathogens of many annual and perennial crops. Crop protection is largely based on genetic and chemical control. Fungicide resistance is a significant issue that has affected many crop pathogens. Some pathogens have rapidly developed resistance and hence are regarded as high-risk species. Rust fungi have been classified as being low risk, in spite of sharing many relevant features with high-risk pathogens. An examination of the evidence suggests that rust fungi may be wrongly classified as low risk. Of the nine classes of fungicide to which resistance has developed, six are inactive against rusts. The three remaining classes are quinone outside inhibitors (QoIs), demethylation inhibitors (DMIs) and succinate dehydrogenase inhibitors (SDHIs). QoIs have been protected by a recently discovered intron that renders resistant mutants unviable. Low levels of resistance have developed to DMIs, but with limited field significance. Older SDHI fungicides were inactive against rusts. Some of the SDHIs introduced since 2003 are active against rusts, so it may be that insufficient time has elapsed for resistance to develop, especially as SDHIs are generally sold in mixtures with other actives. It would therefore seem prudent to increase the level of vigilance for possible cases of resistance to established and new fungicides in rusts.

  16. Neutron scattering studies of stripe correlations in curate oxide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Masaki, E-mail: fujita@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan)

    2012-11-01

    In the last quarter of a century, neutron-scattering measurements have provided important clues for understanding the novel magnetism of carrier doped cuprate oxides. Discovery of evidence for charge-density-wave (CDW) and spin-density-wave (SDW) orders in La{sub 1.6-x}Nd{sub 0.4}Sr{sub x}CuO{sub 4} with x {approx} 1/8 has attracted much attention on the universality of inhomogeneous carrier distribution in CuO{sub 2} planes, namely stripe correlations, and its relevance to the superconductivity. Here we review the nature of charge and spin stripe orders in a prototypical superconducting La-214 system, which has been investigated mainly by neutron scattering measurements. After introducing the hole concentration range, where the each order can be observed, characteristic features of low-energy spin fluctuations in the stripe ordered and disordered La{sub 2-x}Ba{sub x}CuO{sub 4} with x {approx} 1/8 will be discussed in terms of fluctuating stripes. The impact of magnetic field and impurity substitution on the orders is also presented, followed by a comparative study on electron-doped cuprates. Finally, we will give a brief summary of experimental trends.

  17. Siim Nestor soovitab : Supreme 7aastane. White Stripes / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2005-01-01

    Kolmik Supreme tähistab oma 7. tegutsemisaastat 24. juunil Von Krahlis, kus toimub ka Krecki debüütalbumi "If You Live" (väljaandjaks ettevõte Umblu) esitlus. Detroidi blues-rock duo White Stripes esitleb oma uut albumit "Get Behind Me Satan" 29. juunil Tallinnas klubis Hollywood

  18. Dissolved oxygen concentration affects hybrid striped bass growth

    Science.gov (United States)

    Management of dissolved oxygen (DO) concentration in ponds at night during the growing season is important because fish growth and yield are greater in ponds with higher nightly DO concentrations. Three studies were conducted to quantify performance traits and metabolic responses of hybrid striped b...

  19. Earth Magnetism: Teaching "Magnetic Stripes" to Secondary Science Students

    Science.gov (United States)

    Thomas, Owain

    2002-01-01

    Pupils need to grasp many linked concepts to understand how observed magnetic stripes can be produced by sea floor spreading, as required by some courses. This article suggest simple practical demonstrations that can be of great help. (Contains 2 online resources and 2 figures.)

  20. Endogenous silencing of Puccinia triticina pathogenicity genes through in planta-expressed sequences leads to the suppression of rust diseases on wheat.

    Science.gov (United States)

    Panwar, Vinay; McCallum, Brent; Bakkeren, Guus

    2013-02-01

    Rust fungi are destructive plant pathogens. The draft genomes of several wheat-infecting species have been released and potential pathogenicity genes identified through comparative analyses to fungal pathogens that are amenable to genetic manipulation. Functional gene analysis tools are needed to understand the infection process of these obligate parasites and to confirm whether predicted pathogenicity genes could become targets for disease control. We have modified an Agrobacterium tumefaciens-mediated in planta-induced transient gene silencing (PITGS) assay for use in Triticum spp. (wheat), and used this assay to target predicted wheat leaf rust fungus, Puccinia triticina (Pt) pathogenicity genes, a MAP kinase (PtMAPK1), a cyclophilin (PtCYC1) and calcineurin B (PtCNB), to analyze their roles in disease. Agroinfiltration effectively delivered hairpin silencing constructs in wheat, leading to the generation of fungal gene-specific siRNA molecules in infiltrated leaves, and resulting in up to 70% reduction in transcription of the endogenous target genes in superinfected Pt. In vivo silencing caused severe disease suppression, compromising fungal growth and sporulation, as viewed by confocal microscopy and measured by reductions in fungal biomass and emergence of uredinia. Interestingly, using the same gene constructs, suppression of infection by Puccinia graminis and Puccinia striiformis was also achieved. Our results show that A. tumefaciens-mediated PITGS can be used as a reverse-genetics tool to discover gene function in rust fungi. This proof-of-concept study indicates that the targeted fungal transcripts might be important in pathogenesis, and could potentially be used as promising targets for developing RNA interference-based resistance against rust fungi.

  1. Magnetic coupling and exchange stiffness in striped MnAs films

    Science.gov (United States)

    Tolinski, T.; Lindner, J.; Lenz, K.; Baberschke, K.; Ney, A.; Hesjedal, T.; Pampuch, C.; Däweritz, L.; Koch, R.; Ploog, K. H.

    2004-12-01

    We provide the first direct evidence of interactions in a self-organized pattern of coexisting ferromagnetic and paramagnetic MnAs stripe domains as a function of the coupling strength between the stripes (inter) and within one stripe (intra). The value of the intra exchange constant A = 17.7 × 10-10 erg/cm is determined unambiguously from spin wave resonance. Additionally, in-plane ferromagnetic resonance measurements reveal the presence of a strong coupling between the neighboring stripes, which can dominate the weak intra-stripe interaction.

  2. Biological Control of Yellow Nutsedge with the Indigenous Rust Fungus Puccinia canaliculata.

    Science.gov (United States)

    Phatak, S C; Sumner, D R; Wells, H D; Bell, D K; Glaze, N C

    1983-03-25

    Yellow nutsedge (Cyperus esculentus L.) is a serious weed problem in the United States and other countries. An indigenous rust fungus [Puccinia canaliculata (Schw.) Lagerh.], pathogenic on yellow nutsedge, was released in early spring as a potential biological control agent. The fungus inhibited nutsedge flowering and new tuber formation. The fungus also dehydrated and killed nutsedge plants. The successful control of yellow nutsedge by a rust epiphytotic under experimental conditions demonstrates the potential use of the rust in an integrated weed management system. PMID:17735196

  3. The effect of nitrogen application on the development of rusts on wheat varieties

    Directory of Open Access Journals (Sweden)

    M. E. Haggag

    2014-11-01

    Full Text Available The effect of four different levels of nitrogen fertilization on the severity of rusts on three local Egyptian wheat varieties have been investigated. Nitrogen fertilizer was at the rates 0, 40, 60, and 80 kg nitrogen per feddan. Data obtained indicated that resistance of the varieties did not change while percent severity of postules on susceptible, moderately susceptible and moderately resistant varieties was increased as the level of nitrogen fertilization increased. Heavy doses of nitrogen promoted the size and frequency of postules and hence the rust growth and predisposed the plants to higher infection with rusts.

  4. Corrosion-Resistant Amorphous Alloy Ribbons for Electromagnetic Filtration of Iron Rusts from Water

    OpenAIRE

    Kawashima, Asahi; Asami, Katsuhiko; Sato, Takeaki; Hashimoto, Koji

    1985-01-01

    An attempt was made to use corrosion-resistant amorphous Fe-9Cr-13P-7C alloy ribbons as an electromagnetic filter material for trapping various iron rusts suspended in water at 40℃. The ferrimagnetic Fe_3O_4 rust was trapped with the 100% efficiency and paramagnetic rusts such as α-Fe_2O_3, α-FeOOH and amorphous ferric oxyhydroxide were trapped with certain efficiencies at the magnetic field strength of 0.5-10 kOe. The regeneration of the filter by back-washing was easy. The trapping capacity...

  5. Leaf rust (Puccinia triticina) resistance in wheat (Triticum aestivum) cultivars grown in Northern Europe 1992-2002.

    Science.gov (United States)

    Hysing, Shu-Chin; Singh, Ravi P; Huerta-Espino, Julio; Merker, Arnulf; Liljeroth, Erland; Diaz, Oscar

    2006-12-01

    Diversity of resistance to leaf rust caused by Puccinia triticina can be enhanced in wheat (Triticum aestivum) cultivars through a better knowledge of resistance genes that are present in important cultivars and germplasm. Multi-pathotype tests on 84 wheat cultivars grown in Denmark, Finland, Norway and Sweden during 1992-2002 and 39 differential testers enabled the postulation of nine known genes for seedling resistance to leaf rust. Genes Lr1, Lr2a, Lr3, Lr10, Lr13, Lr14a, Lr17, Lr23 and Lr26 were found singly or in combination in 47 of the cultivars (55.9%). The most frequently occurring genes in cultivars grown in Sweden were Lr13 (20.4%), Lr14a (14.8%) and Lr26 (14.8%). Lr14a was the most common gene in cultivars grown in Norway (18.7%), Lr13 in Denmark (35.5%) and Lr10 in Finland (20.0%). Although 28 cultivars (33.3%) exhibited a response pattern that could not be assigned to resistance genes or combinations present in the tester lines, several pathotypes carried virulence and hence these genes or combinations are of limited use. Nine cultivars (10.7%) lacked detectable seedling resistance. One cultivar was resistant to all pathotypes used in the study. PMID:17362328

  6. Pyramiding the disease resistant genes to southern rust and stalk rot in maize(Zea mays L.) with marker-assisted selection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Southern corn rust(SCR) caused by Puccinia polysora Underw and maize stalk rot caused by Pythium inflatum Matthews(MSR-2) are two destructive diseases of maize(Zea mays L.) in China.Our previous studies indicated that maize inbred line Qi319 is highly resistant to SCR but susceptible to MSR-2,while inbred line 1145 is highly resistant to MSR-2 but susceptible to SCR.The SCR resistant gene(RppQ) in Qi319 and MSR-2 resistant gene(Rpi1) in 1145 have been mapped on chromosome 10 and 4 respectively.In this resea...

  7. Modeling the effects of potential salinity shifts on the recovery of striped bass in the Savannah River estuary, Georgia-South Carolina, United States

    Science.gov (United States)

    Reinert, T.R.; Peterson, J.T.

    2008-01-01

    Increased salinity in spawning and nursery grounds in the Savannah River estuary was cited as the primary cause of a 97% decrease in adult striped bass (Morone saxatilis) and a concomitant 96% decrease in striped bass egg production. Restoration efforts focused on environmental remediation and stock enhancement have resulted in restored salinity patterns and increased egg and adult abundances. However, future water needs or harbor development may preclude further recovery by reducing freshwater inflow or increasing salinity intrusion. To assess the effect of potential changes in the salinity regime, we developed models relating discharge, tidal phase, and salinity to striped bass egg and early larval survival and re-cast these in a quantitative Bayesian belief network. The model indicated that a small upstream shift (???1.67 km) in the salinity regime would have the least impact on striped bass early life history survival, whereas shifts >1.67 km would have progressively larger impacts, with a 8.33-km shift potentially reducing our estimated survival probability by >28%. Such an impact could have cumulative and long-term detrimental effects on the recovery of the Savannah River striped bass population. The available salinity data were collected during average and low flows, so our model represents some typical and some extreme conditions during a striped bass spawning season. Our model is a relatively simplistic, "first-order" attempt at evaluating potential effects of changes in the Savannah River estuarine salinity regime and points to areas of concern and potential future research. ?? 2008 Springer Science+Business Media, LLC.

  8. Visualization analysis of tiger-striped flow mark generation phenomena in injection molding

    Science.gov (United States)

    Owada, Shigeru; Yokoi, Hidetoshi

    2016-03-01

    The generation mechanism of tiger-striped flow marks of polypropylene (PP)/rubber/talc blends in injection molding was investigated by dynamic visualization analysis in a glass-inserted mold. The analysis revealed that the behavior of the melt flow front correlates with the flow mark generation. The cloudy part in the tiger-striped flow marks corresponded to the low transcription rate area of the melt diverging near the cavity wall, while the glossy part corresponded to the high transcription rate area of the melt converging toward the cavity wall side. The melt temperature at the high transcription rate area was slightly lower than that at the low transcription rate area. These phenomena resulted due to the difference in the temperature of the melt front that was caused by the asymmetric fountain flow. These results suggest the followings; At the moment when the melt is broken near the one side of cavity wall due to piling the extensional strains up to a certain level, the melt spurts out near the broken side. It results in generating asymmetric fountain flow temporarily to relax the extensional front surface, which moves toward the opposite side to form the high transcription area.

  9. DE-STRIPING FOR TDICCD REMOTE SENSING IMAGE BASED ON STATISTICAL FEATURES OF HISTOGRAM

    Directory of Open Access Journals (Sweden)

    H.-T. Gao

    2016-06-01

    Full Text Available Aim to striping noise brought by non-uniform response of remote sensing TDI CCD, a novel de-striping method based on statistical features of image histogram is put forward. By analysing the distribution of histograms,the centroid of histogram is selected to be an eigenvalue representing uniformity of ground objects,histogrammic centroid of whole image and each pixels are calculated first,the differences between them are regard as rough correction coefficients, then in order to avoid the sensitivity caused by single parameter and considering the strong continuity and pertinence of ground objects between two adjacent pixels,correlation coefficient of the histograms is introduces to reflect the similarities between them,fine correction coefficient is obtained by searching around the rough correction coefficient,additionally,in view of the influence of bright cloud on histogram,an automatic cloud detection based on multi-feature including grey level,texture,fractal dimension and edge is used to pre-process image.Two 0-level panchromatic images of SJ-9A satellite with obvious strip noise are processed by proposed method to evaluate the performance, results show that the visual quality of images are improved because the strip noise is entirely removed,we quantitatively analyse the result by calculating the non-uniformity ,which has reached about 1% and is better than histogram matching method.

  10. De-Striping for Tdiccd Remote Sensing Image Based on Statistical Features of Histogram

    Science.gov (United States)

    Gao, Hui-ting; Liu, Wei; He, Hong-yan; Zhang, Bing-xian; Jiang, Cheng

    2016-06-01

    Aim to striping noise brought by non-uniform response of remote sensing TDI CCD, a novel de-striping method based on statistical features of image histogram is put forward. By analysing the distribution of histograms,the centroid of histogram is selected to be an eigenvalue representing uniformity of ground objects,histogrammic centroid of whole image and each pixels are calculated first,the differences between them are regard as rough correction coefficients, then in order to avoid the sensitivity caused by single parameter and considering the strong continuity and pertinence of ground objects between two adjacent pixels,correlation coefficient of the histograms is introduces to reflect the similarities between them,fine correction coefficient is obtained by searching around the rough correction coefficient,additionally,in view of the influence of bright cloud on histogram,an automatic cloud detection based on multi-feature including grey level,texture,fractal dimension and edge is used to pre-process image.Two 0-level panchromatic images of SJ-9A satellite with obvious strip noise are processed by proposed method to evaluate the performance, results show that the visual quality of images are improved because the strip noise is entirely removed,we quantitatively analyse the result by calculating the non-uniformity ,which has reached about 1% and is better than histogram matching method.

  11. Sustained eruptions on Enceladus explained by turbulent dissipation in tiger stripes

    CERN Document Server

    Kite, Edwin S

    2016-01-01

    Spacecraft observations suggest that the plumes of Saturn's moon Enceladus draw water from a subsurface ocean, but the sustainability of conduits linking ocean and surface is not understood. Observations show sustained (though tidally modulated) fissure eruptions throughout each orbit, and since the 2005 discovery of the plumes. Peak plume flux lags peak tidal extension by $\\sim$1 radian, suggestive of resonance. Here we show that a model of the tiger stripes as tidally-flexed slots that puncture the ice shell can simultaneously explain the persistence of the eruptions through the tidal cycle, the phase lag, and the total power output of the tiger stripe terrain, while suggesting that the eruptions are maintained over geological timescales. The delay associated with flushing and refilling of \\emph{O}(1) m-wide slots with ocean water causes erupted flux to lag tidal forcing and helps to buttress slots against closure, while tidally pumped in-slot flow leads to heating and mechanical disruption that staves off ...

  12. Online identification guides for Australian smut fungi (Ustilaginomycotina) and rust fungi (Pucciniales).

    Science.gov (United States)

    Shivas, Roger G; Beasley, Dean R; McTaggart, Alistair R

    2014-12-01

    Interactive identification keys for Australian smut fungi (Ustilaginomycotina and Pucciniomycotina, Microbotryales) and rust fungi (Pucciniomycotina, Pucciniales) are available online at http://collections.daff.qld.gov.au. The keys were built using Lucid software, and facilitate the identification of all known Australian smut fungi (317 species in 37 genera) and 100 rust fungi (from approximately 360 species in 37 genera). The smut and rust keys are illustrated with over 1,600 and 570 images respectively. The keys are designed to assist a wide range of end-users including mycologists, plant health diagnosticians, biosecurity scientists, plant pathologists, and university students. The keys are dynamic and will be regularly updated to include taxonomic changes and incorporate new detections, taxa, distributions and images. Researchers working with Australian smut and rust fungi are encouraged to participate in the on-going development and improvement of these keys. PMID:25734028

  13. Rust characterisation of ancient iron artefacts exposed to indoor atmospheric corrosion

    International Nuclear Information System (INIS)

    A corpus of eleven iron artefacts exposed several centuries to indoor atmospheric corrosion has been collected. The general morphology of the rust layers has been studied as well as the iron substrate. Second phase particles (slag inclusions) and minor elements (carbon, phosphorus) were detected. The compositions of the rust layers have been analysed by EPMA on cross sections. The distribution of endogenous and exogenous elements has been studied. An original analytical method (micro XRD under synchrotron radiation) was used to study the structure distribution on thin film transverse sections. Using this technique, the different constitutive crystallized phases in the rust layer have been localised. Goethite has been detected preferentially in inner layers, lepidocrocite in outer layers. The goethite to lepidocrocite content ratio in the rust layers, the so-called protective ability index α/γ has been calculated and compared to values found in literature. (authors)

  14. BARLEY LEAF RUST (PUCCINIA HORDEI OTTH. PATHOGEN IN THE NORTH CAUCASUS: SPREAD AND RASE COMPOSITION

    Directory of Open Access Journals (Sweden)

    Danilova A. V.

    2014-09-01

    Full Text Available The spread of barley dwarf rust pathogen has been studied in five agro-climatic zones of North Caucasus in 2012-2013. The race composition of the North Caucasian pathogen population was identified

  15. Recent invasion of world-wide wheat growing areas by two aggressive strains of Puccinia striiformis

    DEFF Research Database (Denmark)

    Walter, Stephanie; Ali, Sajid; Justesen, Annemarie Fejer;

    2012-01-01

    The ever more frequent and severe large-scale epidemics of wheat yellow/stripe rust disease (caused by Puccinia striiformis) pose a severe threat to the world’s wheat production (Hovmøller et al. 2010). The onset of a new series of world-wide wheat yellow rust epidemics in 2000 has been linked...

  16. 16 CFR 23.10 - Misuse of “corrosion proof,” “noncorrosive,” “corrosion resistant,” “rust proof,” “rust resistant...

    Science.gov (United States)

    2010-01-01

    ... INDUSTRIES § 23.10 Misuse of “corrosion proof,” “noncorrosive,” “corrosion resistant,” “rust proof,” “rust resistant,” etc. (a) It is unfair or deceptive to: (1) Use the terms “corrosion proof,” “noncorrosive... the product will be immune from rust and other forms of corrosion during the life expectancy of...

  17. Genetically engineered stem rust resistance in barley using the Rpg1 gene

    OpenAIRE

    Horvath, Henriette; Rostoks, Nils; Brueggeman, Robert; Steffenson, Brian; von Wettstein, Diter; Kleinhofs, Andris

    2002-01-01

    The stem-rust-susceptible barley cv. Golden Promise was transformed by Agrobacterium-mediated transformation of immature zygotic embryos with the Rpg1 genomic clone of cv. Morex containing a 520-bp 5′ promoter region, 4,919-bp gene region, and 547-bp 3′ nontranscribed sequence. Representatives of 42 transgenic barley lines obtained were characterized for their seedling infection response to pathotype Pgt-MCC of the stem rust fungus Puccinia graminis f. sp. tritici. Golden Promise was converte...

  18. Stripe-PZT Sensor-Based Baseline-Free Crack Diagnosis in a Structure with a Welded Stiffener

    Science.gov (United States)

    An, Yun-Kyu; Shen, Zhiqi; Wu, Zhishen

    2016-01-01

    This paper proposes a stripe-PZT sensor-based baseline-free crack diagnosis technique in the heat affected zone (HAZ) of a structure with a welded stiffener. The proposed technique enables one to identify and localize a crack in the HAZ using only current data measured using a stripe-PZT sensor. The use of the stripe-PZT sensor makes it possible to significantly improve the applicability to real structures and minimize man-made errors associated with the installation process by embedding multiple piezoelectric sensors onto a printed circuit board. Moreover, a new frequency-wavenumber analysis-based baseline-free crack diagnosis algorithm minimizes false alarms caused by environmental variations by avoiding simple comparison with the baseline data accumulated from the pristine condition of a target structure. The proposed technique is numerically as well as experimentally validated using a plate-like structure with a welded stiffener, reveling that it successfully identifies and localizes a crack in HAZ. PMID:27649200

  19. Stripe-PZT Sensor-Based Baseline-Free Crack Diagnosis in a Structure with a Welded Stiffener.

    Science.gov (United States)

    An, Yun-Kyu; Shen, Zhiqi; Wu, Zhishen

    2016-01-01

    This paper proposes a stripe-PZT sensor-based baseline-free crack diagnosis technique in the heat affected zone (HAZ) of a structure with a welded stiffener. The proposed technique enables one to identify and localize a crack in the HAZ using only current data measured using a stripe-PZT sensor. The use of the stripe-PZT sensor makes it possible to significantly improve the applicability to real structures and minimize man-made errors associated with the installation process by embedding multiple piezoelectric sensors onto a printed circuit board. Moreover, a new frequency-wavenumber analysis-based baseline-free crack diagnosis algorithm minimizes false alarms caused by environmental variations by avoiding simple comparison with the baseline data accumulated from the pristine condition of a target structure. The proposed technique is numerically as well as experimentally validated using a plate-like structure with a welded stiffener, reveling that it successfully identifies and localizes a crack in HAZ. PMID:27649200

  20. Development of Electric Rust Prevention Machining Method in End Mill Cutting

    Science.gov (United States)

    Nishikawa, Naohiro; Tsukamoto, Shinya; Ohashi, Kazuhito; Miyake, Ryusuke; Iyama, Toshirou; Mizuno, Masahiro

    In a machining plant, cutting fluids, such as water immiscible or miscible types are in danger of harming an operator's health. Moreover, infinite cost and heavy environmental loading have arisen as issues for waste fluid disposal treatment. The electric rust prevention machining method has prevented the fatal rust of work pieces by supplying a slight electric current while using only harmless water and non-using rust preventive agent. The application of this method to the end mill cutting is being experimentally investigated. A stable electric current supply is realized by using a constant current control and an appropriate electrode combination. In addition, this method achieved rust prevention of work pieces for 3 hours. Moreover, an effective rust prevention time and current area of 1 hour is clarified and rust prevention power is indicated as a low 0.0122W. Afterwards, it was evaluated that hydrogen embrittlement of work piece was safe in practical use. Subsequently, cutting performance using this method as machining on a work piece dipped in water is compared with conventional cutting methods. When performing light cutting, this method is inferior to a water immiscible cutting fluid, however surface roughness is improved more than with a water miscible cutting fluid. Therefore, this method is considered to have potential as a the new environmental harmonic machining method.

  1. Striping noise mitigation in ATMS brightness temperatures and its impact on cloud LWP retrievals

    Science.gov (United States)

    Ma, Yuan; Zou, Xiaolei

    2015-07-01

    Advanced Technology Microwave Sounder (ATMS) on board Suomi National Polar-orbiting Partnership (NPP) satellite provides global distributions of microwave brightness temperature measurements at 22 temperature and humidity sounding channels twice daily. However, the differences between observations and brightness temperature simulations exhibit a systematic along-track striping noise for all channels. In this study, a set of 22 "optimal" filters is designed to remove the striping noise in different channels. It is shown that the original method for ATMS striping noise mitigation developed by Qin et al. can be simplified and made suitable for use in an operational context. Impacts of striping noise mitigation on small-scale weather features are investigated by comparing ATMS cloud liquid water path (LWP) retrieved before and after striping noise mitigation. It is shown that the optimal filters do not affect small-scale cloud features while smoothing out striping noise in brightness temperatures. It is also shown that the striping noise is present in the LWP retrievals if the striping noise in brightness temperatures of ATMS channels 1 and 2 is not removed. The amplitude of the striping noise in LWP is linearly related to the magnitude of striping noise in ATMS brightness temperature observations.

  2. A summary of information on the rust Puccinia psidii Winter (guava rust) with emphasis on means to prevent introduction of additional strains to Hawaii

    Science.gov (United States)

    Loope, Lloyd

    2010-01-01

    The neotropical rust fungus Puccinia psidii(P. psidii) was originally described from the host common guava in its native Brazil but has been found since on hosts throughout the myrtle family (Myrtaceae), including a dramatic host jump to nonnative Eucalyptus plantations. Most rust fungi are able to live only on a very narrow range of host species. P. psidii is unusual both for having a broad host range and for the intensity of its damage to susceptible young growth. This rust first got a foothold in the United States in Florida more than three decades ago. The U.S. Department of Agriculture (USDA) has since considered it a nonactionable, nonreportable pest. Hawaii and Florida are the only two states with native species in the myrtle family. Over a period of 30 years, this rust has done little damage to any of the scattered native Myrtaceae in Florida, although the host range of the rust has gradually grown to about 30 mostly nonnative species in the family, apparently because of increasing genetic variety of the rust by repeated introductions. However, Florida’s native Myrtaceae are among the roughly 1,100 neotropical species that are largely resistant to P. psidii. The 3,000 species of non-neotropical Myrtaceae of the Pacific, Australia, Asia, and Africa are expected to prove much more vulnerable to P. psidii. Little is known about the genetics or genetic strains of P. psidii, although existing literature shows that there are numerous strains that have differential ability to infect suites of host plants.

  3. Adult neurogenesis in the four-striped mice (Rhabdomys pumilio)

    Institute of Scientific and Technical Information of China (English)

    Olatunbosun O Olaleye; Amadi O Ihunwo

    2014-01-01

    In this study, we investigated non-captive four-striped mice (Rhabdomys pumilio) for evidence that adult neurogenesis occurs in the adult brain of animal models in natural environment. Ki-67 (a marker for cell proliferation) and doublecortin (a marker for immature neurons) immunos-taining conifrmed that adult neurogenesis occurs in the active sites of subventricular zone of the lateral ventricle with the migratory stream to the olfactory bulb, and the subgranular zone of the dentate gyrus of the hippocampus. No Ki-67 proliferating cells were observed in the striatum substantia nigra, amygdala, cerebral cortex or dorsal vagal complex. Doublecortin-immunore-active cells were observed in the striatum, third ventricle, cerebral cortex, amygdala, olfactory bulb and along the rostral migratory stream but absent in the substantia nigra and dorsal vagal complex. The potential neurogenic sites in the four-striped mouse species could invariably lead to increased neural plasticity.

  4. Glyphosate sobre a resistência à ferrugem (Puccinia psidii do eucalipto Glyphosate on eucalyptus resistance to rust (Puccinia psidii

    Directory of Open Access Journals (Sweden)

    L.D. Tuffi Santos

    2007-03-01

    ça. Conclui-se que o glyphosate não afetou a resistência do eucalipto a Puccinia psidii, ocorrendo diminuição da severidade da doença em plantas expostas ao glyphosate via deriva, e que existe tolerância diferencial entre os clones ao herbicida.Glyphosate is the herbicide most applied on eucalyptus plantations for weed control, acting directly on the shikimic acid pathway, the main via for the formation of compounds connected with the natural defenses of the plant, such as lignin, salicytic acid and phytoalexins. Thus, glyphosate contact with the leaves of the plant through drift may have important consequences for disease resistance. The aim of our research was to evaluate glyphosate drift involvement with severity of rust caused by Puccinia psidii in genotypes with different levels of resistance to the pathogen, after inoculation in a controlled environment. Seedlings of four clones, two heterozygote clones resistant to rust (UFV01 and UFV02 and two homozygote clones susceptible to rust (UFV03 and UFV04 were submitted to sub-doses of 0 (control; 28.8, 57.6, 86.4 and 115.2 g ha-1 of glyphosate simulating drift. Three days after glyphosate application, the plants were inoculated with UFV01 isolated from P. psidii obtained from Eucalyptus grandis in the Itapetininga region. On day 21 after inoculation, the following parameters were evaluated: rust intensity, by means of a diagrammatic scale with four classes of severity (SO and S2 resistant to rust and S2 and S3 susceptible to rust, number of pustules per leaf area, area affected by rust, average number of urediniospores cm-2, glyphosate percentage intoxication, and average number of urediniospores/pustule. Clone UFV04 was found to be the most susceptible while UFV01 was the most tolerant to the herbicide. Drift did not change the level of resistance to rust with respect to the resistant genotypes (UFV01 and UFV02 which presented no pustule both in plants exposed to drift and control plants. Susceptibility was maintained

  5. NATURAL TRANSVERSE VIBRATIONS OF A PRESTRESSED ORTHOTROPIC PLATE-STRIPE

    Directory of Open Access Journals (Sweden)

    Egorychev Oleg Aleksandrovich

    2012-10-01

    Full Text Available The article represents a new outlook at the boundary-value problem of natural vibrations of a homogeneous pre-stressed orthotropic plate-stripe. In the paper, the motion equation represents a new approximate hyperbolic equation (rather than a parabolic equation used in the majority of papers covering the same problem describing the vibration of a homogeneous orthotropic plate-stripe. The proposed research is based on newly derived boundary conditions describing the pin-edge, rigid, and elastic (vertical types of fixing, as well as the boundary conditions applicable to the unfixed edge of the plate. The paper contemplates the application of the Laplace transformation and a non-standard representation of a homogeneous differential equation with fixed factors. The article proposes a detailed representation of the problem of natural vibrations of a homogeneous orthotropic plate-stripe if rigidly fixed at opposite sides; besides, the article also provides frequency equations (no conclusions describing the plate characterized by the following boundary conditions: rigid fixing at one side and pin-edge fixing at the opposite side; pin-edge fixing at one side and free (unfixed other side; rigid fixing at one side and elastic fixing at the other side. The results described in the article may be helpful if applied in the construction sector whenever flat structural elements are considered. Moreover, specialists in solid mechanics and theory of elasticity may benefit from the ideas proposed in the article.

  6. Gaze Stripes: Image-Based Visualization of Eye Tracking Data.

    Science.gov (United States)

    Kurzhals, Kuno; Hlawatsch, Marcel; Heimerl, Florian; Burch, Michael; Ertl, Thomas; Weiskopf, Daniel

    2016-01-01

    We present a new visualization approach for displaying eye tracking data from multiple participants. We aim to show the spatio-temporal data of the gaze points in the context of the underlying image or video stimulus without occlusion. Our technique, denoted as gaze stripes, does not require the explicit definition of areas of interest but directly uses the image data around the gaze points, similar to thumbnails for images. A gaze stripe consists of a sequence of such gaze point images, oriented along a horizontal timeline. By displaying multiple aligned gaze stripes, it is possible to analyze and compare the viewing behavior of the participants over time. Since the analysis is carried out directly on the image data, expensive post-processing or manual annotation are not required. Therefore, not only patterns and outliers in the participants' scanpaths can be detected, but the context of the stimulus is available as well. Furthermore, our approach is especially well suited for dynamic stimuli due to the non-aggregated temporal mapping. Complementary views, i.e., markers, notes, screenshots, histograms, and results from automatic clustering, can be added to the visualization to display analysis results. We illustrate the usefulness of our technique on static and dynamic stimuli. Furthermore, we discuss the limitations and scalability of our approach in comparison to established visualization techniques.

  7. Evaluation of Local Wheat Cultivars Susceptibility to infection with Black Stem Rust

    International Nuclear Information System (INIS)

    The present study was conducted to assess the susceptibility of seven local wheat cultivars from Palestine to infection with black stem rust caused by Puccinia graminis f. sp. tritici. Two techniques of disease inoculation were applied during bioassays: global inoculation of entire wheat plants with urediospores and localized inoculation with urediospores and localized inoculation with urediospores on wheat leaf-pieces incubated under humid conditions. Susceptibility of tested cultivars was evaluated according to disease scale based on number and size of typical unredial pustules that appeared after inoculation on entire plants or leaf pieces. Results obtained on bioassay of susceptibility and disease rating on entire plants indicated that Anbar, Kamata and Hetiya safra cultivars were the least susceptible to P. g. tritici infection, whereas Debiya beda cultivar was the most susceptible. The other tested cultivars such as Nab-El-Jama, sawda and Senf 870 were moderately susceptible. On leaf-pieces, Anbar and Kamatat were the least susceptible cultivars, whereas Debiya beda and Nab-El-Jamal were the most susceptible cultivars. The other tested cultivars such as Debiya swada, Senf 870 and Hetiya safra were moderately susceptible. Significant reductions were obtained for the size of unredial postules formed on leaf-pieces when inoculated in an unwounded state compared to the wounded indicating the importance of wounds during inoculation. The global results indicated the possibility of using above method of disease inoculating, scaling and rating for evaluation of wheat cultivars susceptibility for the eventual use in breeding program for resistant varieties in Palestine. (author)

  8. Characterization of Five Novel Mitoviruses in the White Pine Blister Rust Fungus Cronartium ribicola

    Science.gov (United States)

    Liu, Jun-Jun; Chan, Danelle; Xiang, Yu; Williams, Holly; Li, Xiao-Rui; Sniezko, Richard A.; Sturrock, Rona N.

    2016-01-01

    The white pine blister rust (WPBR) fungus Cronartium ribicola (J.C. Fisch.) is an exotic invasive forest pathogen causing severe stem canker disease of native white pine trees (subgenus Strobus) in North America. The present study reports discovery of five novel mitoviruses in C. ribicola by deep RNA sequencing. The complete genome of each mitovirus was determined by rapid amplification of cDNA ends (RACE) and reverse transcriptase-polymerase chain reaction (RT-PCR). A single open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) was detected in each of the viral genomes using mitochondrial genetic codes. Phylogenetic analysis indicated that the C. ribicola mitoviruses (CrMV1 to CrMV5) are new putative species of the genus Mitovirus. qRT-PCR and RNA-Seq analyses revealed that viral RNAs were significantly increased in fungal mycelia in cankered pine stems compared to expression during two different stages of spore development, suggesting that viral genome replication and transcription benefit from active growth of the host fungus. CrMVs were widespread with relatively high levels of minor allele frequency (MAF) in western North America. As the first report of mitoviruses in the Class Pucciniomycetes, this work allows further investigation of the dynamics of a viral community in the WPBR pathosystem, including potential impacts that may affect pathogenicity and virulence of the host fungus. PMID:27196406

  9. Quantification and Gene Expression Analysis of Histone Deacetylases in Common Bean during Rust Fungal Inoculation.

    Science.gov (United States)

    Melmaiee, Kalpalatha; Kalavacharla, Venu Kal; Brown, Adrianne; Todd, Antonette; Thurston, Yaqoob; Elavarthi, Sathya

    2015-01-01

    Histone deacetylases (HDACs) play an important role in plant growth, development, and defense processes and are one of the primary causes of epigenetic modifications in a genome. There was only one study reported on epigenetic modifications of the important legume crop, common bean, and its interaction with the fungal rust pathogen Uromyces appendiculatus prior to this project. We measured the total active HDACs levels in leaf tissues and observed expression patterns for the selected HDAC genes at 0, 12, and 84 hours after inoculation in mock inoculated and inoculated plants. Colorimetric analysis showed that the total amount of HDACs present in the leaf tissue decreased at 12 hours in inoculated plants compared to mock inoculated control plants. Gene expression analyses indicated that the expression pattern of gene PvSRT1 is similar to the trend of total active HDACs in this time course experiment. Gene PvHDA6 showed increased expression in the inoculated plants during the time points measured. This is one of the first attempts to study expression levels of HDACs in economically important legumes in the context of plant pathogen interactions. Findings from our study will be helpful to understand trends of total active HDACs and expression patterns of these genes under study during biotic stress.

  10. Quantification and Gene Expression Analysis of Histone Deacetylases in Common Bean during Rust Fungal Inoculation

    Directory of Open Access Journals (Sweden)

    Kalpalatha Melmaiee

    2015-01-01

    Full Text Available Histone deacetylases (HDACs play an important role in plant growth, development, and defense processes and are one of the primary causes of epigenetic modifications in a genome. There was only one study reported on epigenetic modifications of the important legume crop, common bean, and its interaction with the fungal rust pathogen Uromyces appendiculatus prior to this project. We measured the total active HDACs levels in leaf tissues and observed expression patterns for the selected HDAC genes at 0, 12, and 84 hours after inoculation in mock inoculated and inoculated plants. Colorimetric analysis showed that the total amount of HDACs present in the leaf tissue decreased at 12 hours in inoculated plants compared to mock inoculated control plants. Gene expression analyses indicated that the expression pattern of gene PvSRT1 is similar to the trend of total active HDACs in this time course experiment. Gene PvHDA6 showed increased expression in the inoculated plants during the time points measured. This is one of the first attempts to study expression levels of HDACs in economically important legumes in the context of plant pathogen interactions. Findings from our study will be helpful to understand trends of total active HDACs and expression patterns of these genes under study during biotic stress.

  11. Estimation of variability and heritability for morphological traits and leaf rust severity in spring wheat

    Directory of Open Access Journals (Sweden)

    Rudra Bhattarai

    2014-12-01

    Full Text Available The seed materials were received from National Wheat Research Program, Bhairahawa and field experiment was conducted at Regional Agricultural Research Station Tarahara during 2012 and 2013 in wheat growing season. The topography of the experimental site was 130 masl with sandy loam soil. The trial included 24 wheat genotypes laid out in alpha lattice design in eight sub blocks within two main blocks. The eastern region of Nepal has been facing the problem of sterility caused by different stresses during reproductive growth stage. So we need to develop the early maturing variety with high yielding potential that could escape the reproductive damage from rainfall, hot westerly wind and leaf rust epidemic. In this study, we identified BL3594, NL1026, NL297, BL3978 and NL1140 as early maturing wheat genotypes with 102, 102, 101, 97 and 102 days of maturity, respectively. The genotypes varied significantly for heading days, maturity days, plant height, spikes per meter square, grain per spikes and grain yield ton per hector. The most stable yield producing genotypes were BL3264, BL3535, BL3623, NL1135 and BL3978. The variety BL3978 had maturity duration of 97 days, even earlier than check variety NL297. The genotypes NL1093 and NL1094 had highest grain per spikes although had negative correlation coefficient with panicle length consequently led to the lower yield. The new genotypes like BL3978, BL3594 and NL1140 should be promote as appropriate varieties for terai region of Nepal.

  12. Characterization of Five Novel Mitoviruses in the White Pine Blister Rust Fungus Cronartium ribicola.

    Science.gov (United States)

    Liu, Jun-Jun; Chan, Danelle; Xiang, Yu; Williams, Holly; Li, Xiao-Rui; Sniezko, Richard A; Sturrock, Rona N

    2016-01-01

    The white pine blister rust (WPBR) fungus Cronartium ribicola (J.C. Fisch.) is an exotic invasive forest pathogen causing severe stem canker disease of native white pine trees (subgenus Strobus) in North America. The present study reports discovery of five novel mitoviruses in C. ribicola by deep RNA sequencing. The complete genome of each mitovirus was determined by rapid amplification of cDNA ends (RACE) and reverse transcriptase-polymerase chain reaction (RT-PCR). A single open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) was detected in each of the viral genomes using mitochondrial genetic codes. Phylogenetic analysis indicated that the C. ribicola mitoviruses (CrMV1 to CrMV5) are new putative species of the genus Mitovirus. qRT-PCR and RNA-Seq analyses revealed that viral RNAs were significantly increased in fungal mycelia in cankered pine stems compared to expression during two different stages of spore development, suggesting that viral genome replication and transcription benefit from active growth of the host fungus. CrMVs were widespread with relatively high levels of minor allele frequency (MAF) in western North America. As the first report of mitoviruses in the Class Pucciniomycetes, this work allows further investigation of the dynamics of a viral community in the WPBR pathosystem, including potential impacts that may affect pathogenicity and virulence of the host fungus. PMID:27196406

  13. Impurity and magnetic field effects on the stripes in cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Yoji, E-mail: koike@teion.apph.tohoku.ac.jp [Department of Applied Physics, Tohoku University, 6-6-05 Aoba, Aramaki, Sendai 980-8579 (Japan); Adachi, Tadashi [Department of Applied Physics, Tohoku University, 6-6-05 Aoba, Aramaki, Sendai 980-8579 (Japan)

    2012-11-01

    Impurity and magnetic field effects on the stripes are reviewed not only in the La-based cuprates but also in the other high-T{sub c} cuprates. It has turned out that the so-called 1/8 anomaly takes place not only in the La-based cuprates but also in the hole-doped high-T{sub c} cuprates universally, when adequate pinning centers are introduced. Impurity-induced magnetism tends to emerge at low temperatures in a wide range of hole concentration in LSCO, Bi2201 and YBCO where superconductivity appears. Accordingly, it is possible that the dynamically fluctuating stripes exist universally in the hole-doped high-T{sub c} cuprates and play an important role in the appearance of the high-T{sub c} superconductivity. For the hole-doped high-T{sub c} cuprates, it has turned out that magnetic field effects on the stripes are small in samples where the stripes are well stabilized statically in zero field, while field-induced magnetism is observed under magnetic fields parallel to the c-axis in underdoped samples where magnetism is not well developed in zero field. The field-induced magnetism has been observed in some optimally doped samples also, but it has never been observed in overdoped samples. Field-induced CDW has been observed in slightly overdoped BSCCO. These results are understood fundamentally in terms of the theoretical phase diagram as a function of magnetic field, based on the Ginzburg-Landau theory with competing antiferromagnetic and superconducting order parameters. It is also possible to understand that the field-induced magnetism and CDW are due to pinning of the dynamically fluctuating stripes by vortex cores as in the case of the pinning by impurities. In the electron-doped high-T{sub c} cuprates, on the other hand, impurity-induced magnetism has never been observed. The nature of the field-induced magnetism observed in the electron-doped cuprates is different from that in the hole-doped ones.

  14. Characterization of a tryptophan 2-monooxygenase gene from Puccinia graminis f. sp. tritici involved in auxin biosynthesis and rust pathogenicity.

    Science.gov (United States)

    Yin, Chuntao; Park, Jeong-Jin; Gang, David R; Hulbert, Scot H

    2014-03-01

    The plant hormone indole-3-acetic acid (IAA) is best known as a regulator of plant growth and development but its production can also affect plant-microbe interactions. Microorganisms, including numerous plant-associated bacteria and several fungi, are also capable of producing IAA. The stem rust fungus Puccinia graminis f. sp. tritici induced wheat plants to accumulate auxin in infected leaf tissue. A gene (Pgt-IaaM) encoding a putative tryptophan 2-monooxygenase, which makes the auxin precursor indole-3-acetamide (IAM), was identified in the P. graminis f. sp. tritici genome and found to be expressed in haustoria cells in infected plant tissue. Transient silencing of the gene in infected wheat plants indicated that it was required for full pathogenicity. Expression of Pgt-IaaM in Arabidopsis caused a typical auxin expression phenotype and promoted susceptibility to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000.

  15. Evaluation of locally available feed resources for striped catfish (Pangasianodon hypophthalmus)

    OpenAIRE

    Da, Chau Thi

    2012-01-01

    This thesis investigated and compared inputs and outputs, economic factors and current feed use in small-scale farming systems producing striped catfish (Pangasianodon hypophthalmus) in the Mekong Delta. The nutrient content of locally available natural feed resources for striped catfish was determined and growth performance, feed utilisation and body indices were analysed in pond-cultured striped catfish fed diets where fish meal protein was replaced with protein from local feed resources. ...

  16. Heat to Electricity Conversion by a Graphene Stripe with Heavy Chiral Fermions

    OpenAIRE

    Shafranjuk, S. E.

    2012-01-01

    A conversion of thermal energy into electricity is considered in the electrically polarized graphene stripes with zigzag edges where the heavy chiral fermion (HCF) states are formed. The stripes are characterized by a high electric conductance Ge and by a significant Seebeck coefficient S. The electric current in the stripes is induced due to a non-equilibrium thermal injection of "hot" electrons. This thermoelectric generation process might be utilized for building of thermoelectric generato...

  17. The effect of environmental hypercapnia and size on nitrite toxicity in the striped catfish (Pangasianodon hypophthalmus)

    DEFF Research Database (Denmark)

    Hvas, Malthe; Damsgaard, Christian; Gam, Le Thi Hong;

    2016-01-01

    Striped catfish (Pangasianodon hypophthalmus) are farmed intensively at high stocking densities in Vietnam where they are likely to encounter environmental hypercapnia as well as occasional high levels of aquatic nitrite. Nitrite competes with Cl- for uptake at the branchial HCO3-/Cl- exchanger...... to a reduced nitrite uptake. To assess the effect of hypercapnia on nitrite uptake, fish were cannulated in the dorsal aorta, allowing repeated blood sampling for measurements of haemoglobin derivatives, plasma ions and acid-base status during exposure to 0.9 mM nitrite alone and in combination with...... acute and 48 h acclimated hypercapnia over a period of 72 h. Nitrite uptake was initially reduced during the hypercapnia-induced acidosis, but after pH recovery the situation was reversed, resulting in higher plasma nitrite concentrations and lower functional haemoglobin levels that eventually caused...

  18. Zebra Stripes through the Eyes of Their Predators, Zebras, and Humans.

    Directory of Open Access Journals (Sweden)

    Amanda D Melin

    Full Text Available The century-old idea that stripes make zebras cryptic to large carnivores has never been examined systematically. We evaluated this hypothesis by passing digital images of zebras through species-specific spatial and colour filters to simulate their appearance for the visual systems of zebras' primary predators and zebras themselves. We also measured stripe widths and luminance contrast to estimate the maximum distances from which lions, spotted hyaenas, and zebras can resolve stripes. We found that beyond ca. 50 m (daylight and 30 m (twilight zebra stripes are difficult for the estimated visual systems of large carnivores to resolve, but not humans. On moonless nights, stripes are difficult for all species to resolve beyond ca. 9 m. In open treeless habitats where zebras spend most time, zebras are as clearly identified by the lion visual system as are similar-sized ungulates, suggesting that stripes cannot confer crypsis by disrupting the zebra's outline. Stripes confer a minor advantage over solid pelage in masking body shape in woodlands, but the effect is stronger for humans than for predators. Zebras appear to be less able than humans to resolve stripes although they are better than their chief predators. In conclusion, compared to the uniform pelage of other sympatric herbivores it appears highly unlikely that stripes are a form of anti-predator camouflage.

  19. PCR markers for Triticum speltoides leaf rust resistance gene Lr51 and their use to develop isogenic hard red spring wheat lines

    OpenAIRE

    Helguera, M; Vanzetti, L.; Soria, M; Khan, I A; Kolmer, J.; Dubcovsky, Jorge

    2005-01-01

    New leaf rust resistance genes are needed in wheat (Triticum aestivum L.) to provide additional sources of resistance to the highly variable and dynamic leaf rust pathogen Puccinia triticina Eriks. Leaf rust resistance gene Lr51, located within a segment of Triticum speltoides Taush chromosome IS translocated to the long arm of chromosome 1B of bread wheat, is resistant to the current predominant races of leaf rust in the USA. The objectives of this study were to determine the genetic length ...

  20. The Lr46 gene conditions partial adult-plant resistance to yellow rust, stem rust, and powdery mildew in Thatcher wheat

    Science.gov (United States)

    Disease resistance is a critical goal for many wheat improvement programs. Wheat cultivars are often attacked by multiple diseases, including the rusts and powdery mildew. F6 recombinant inbred lines (RILs) derived from the cross of Thatcher*3/CI13227 that had been previously characterized as having...

  1. Development of a new anti-rust paint for rusted metal%新型带锈防锈漆的研制

    Institute of Scientific and Technical Information of China (English)

    应鹏展; 王雅晴

    2001-01-01

    A new anti-rust paint for rusted material was developed by addition of zinc phosphate, zinc oxide, aluminum tripolyphosphate, barium chromate and other auxiliaries, which result in phosphating, and chromating of rusted metal surface to obtain continuous, uniform and fine protective film. Addition of 0.05%~0.10% cobalt and manganese dryer can greatly improve drying rate of paint film. The anti-rust paint is stable in long-term storage and its parameters meet the requirement of national standard. Preparation of the title paint is simple and low cost.%研制了一种新型带锈防锈漆。通过加入磷酸锌、氧化锌、三聚磷酸铝、铬酸钡等助剂,使金属带锈表面锈层磷化、钝化,形成连续、均匀、致密的保护层。加入0.05%~0.10%的钴锰催干剂,显著提高了漆膜的干燥速度。该带锈防锈漆制备工艺简单、成本低、长期贮存性能稳定,各项指标均符合国家标准。

  2. Expression of a Thatcher wheat adult plant stem rust resistance QTL on chromosome arm 2BL is enhanced by Lr34

    Science.gov (United States)

    An F6 recombinant inbred line (RIL) spring wheat population derived from RL6071, a stem rust susceptible line and RL6058, a backcross line of Thatcher wheat with Lr34 that is highly resistant to stem rust, was evaluated for adult plant stem rust resistance in North Dakota in 1999, and in Kenya in 20...

  3. A baseline analysis of the distribution, host-range, and severity of the rust Puccinia Psidii in the Hawaiian islands, 2005-2010

    Science.gov (United States)

    Anderson, Robert C.

    2012-01-01

    Puccinia psidii was first described by Winter (1884) on guava (Psidium guajava L.) in Brazil. The rust is still a major pest of native guava in Brazil and is often referred to as “guava rust” internationally. It is unusual among rust fungi because of its broad and ever-expanding host-range within the Myrtaceae plant family (Simpson et al. 2006). The pathogen is regarded as a major threat to Eucalyptus plantations and other Myrtaceae worldwide (Coutinho et al. 1998, Grgurinovic et al. 2006, Glen et al. 2007). Infections of leaves and meristems are particularly severe on susceptible seedlings, cuttings, young trees, and coppice, causing plants to be stunted and multi-branched, inhibiting normal growth and development, and sometimes causing death to young seedlings (Booth et al. 2000, Rayachhetry et al. 2001). The fungus has expanded its host-range in Brazil, affecting both native and introduced Myrtaceae (Coutinho et al. 1998). Since its discovery in 1884, P. psidii has continually been discovered to have an expanding host-range within the Myrtaceae, affecting hosts throughout much of South and Central America and the Caribbean. Spreading out originally from Brazil in 1884, the fungus has been reported on hosts in the following countries (first record in parentheses): Paraguay (1884), Uruguay (1889), Ecuador (1891), Colombia (1913), Puerto Rico (1913), Cuba (1926), Dominican Republic (1933), Venezuela (1934), Jamaica (1936), Argentina (1946), Dominica (1948), Trinidad and Tobago (1951), Guatemala (1968), United States (Florida; 1977), Mexico (1981), El Salvador (1987), and Costa Rica (1998) (Simpson et al. 2006). It is possible that P. psidii was present in El Salvador and Costa Rica prior to 1980, but was not reported until 1987 and 1998, respectively. Until recently, Puccinia psidii was restricted to the Neotropics, Mexico, and the state of Florida in the United States. While the rust has been present in Florida for over 30 years, only recently has it spread

  4. Genetic Analysis of Major and Minor Gene(s) Resistant to Stripe Rust in Important Resource Wheat Line Jinghe891-1

    Institute of Scientific and Technical Information of China (English)

    XU Shi-chang; ZHANG Jing-yuan; ZHAO Wen-sheng; WU Li-ren; ZHANG Ji-xin; YUAN Zhen-dong

    2002-01-01

    Inheritance of line Jinghe891-1 resistant to pathotype of Puccinia striiformis in two patterns of temperature (Normal: day 18℃/night 10℃, High: day 24℃/night 15℃ )was studied in this paper. The results showed that there were at least two pairs of dominant major genes and one pair of recessive minor genes in Jinghe 891-1. The two pairs of major genes that conferred resistance to CY31 were allelic or linked closely with resistance gene in Jubilejna Ⅱ , Kangyin655 and T. spelta Album. They were novel resistance genes and were inherited in a repeated or independent mode. The minor genes, which could modify the major genes,were sensitive to temperature and conferred resistance to all pathotypes of Puccinia striiformis in China. It is recommended that this line can be used as an important resource stock.

  5. Composition and structure of an iron-bearing, layered double hydroxide (LDH) - Green rust sodium sulphate

    DEFF Research Database (Denmark)

    Christiansen, B. C.; Balic-Zunic, T.; Petit, P. O.;

    2009-01-01

    Mixed-valent Fe(II),Fe(III)-layered hydroxide, known as green rust, was synthesized from slightly basic, sodium sulphate solutions in an oxygen-free glove box. Solution conditions were monitored with pH and Eh electrodes and optimized to ensure a pure sulphate green-rust phase. The solid...... was characterised using Mossbauer spectroscopy, X-ray diffraction, scanning electron microscopy and atomic force microscopy. The composition of the solution from which the green rust precipitated was established by mass and absorption spectroscopy. The sulphate form of green rust is composed of brucite-like layers......(III)(3)(SO4)(2)(OH)(18)center dot 12H(2)O, space group P-3, a = 9.528(6) angstrom, c = 10.968(8) angstrom and Z = 1. Green rust sodium sulphate, GR(Na,SO4) crystallizes in thin, hexagonal plates. Particles range from less than 50 nm to 2 mu m in diameter and are 40 nm thick or less. The material is redox...

  6. QTL mapping provides evidence for lack of association of the avoidance of leaf rust in Hordeum chilense with stomata density

    NARCIS (Netherlands)

    Vaz Patto, M.C.; Rubiales, D.; Martin, A.; Hernandez, P.; Lindhout, W.H.; Niks, R.E.; Stam, P.

    2003-01-01

    In cereals, rust fungi are among the most harmful pathogens. Breeders usually rely on short-lived hypersensitivity resistance. As an alternative, "avoidance" may be a more durable defence mechanism to protect plants to rust fungi. In Hordeum chilense avoidance is based on extensive wax covering of s

  7. Transformation of hydroxycarbonate green rust into crystalline iron (hydr)oxides: Influences of reaction conditions and underlying mechanisms

    NARCIS (Netherlands)

    Wang, Xiaoming; Liu, Fan; Tan, W.; Feng, Xionghan; Koopal, L.K.

    2013-01-01

    Green rusts (GRs) are found as intermediate products between FeII hydroxides and FeIII oxyhydroxides in various anoxic environments. The transformation of hydroxycarbonate green rust GR1(CO32-) by air oxidation at different conditions and the underlying mechanisms were investigated using X-ray diffr

  8. Concerted action of two avirulent spore effectors activates Reaction to Puccinia graminis 1 (Rpg1)-mediated cereal stem rust resistance

    Science.gov (United States)

    The barley stem rust resistance gene Reaction to Puccinia graminis 1 (Rpg1), encoding a receptor-like kinase, confers durable resistance to the stem rust pathogen Puccinia graminis f. sp. tritici. The fungal urediniospores form adhesion structures with the leaf epidermal cells within 1 h of inocula...

  9. Morphology of germlings of urediniospores and its value for the identification and classification of grass rust fungi.

    NARCIS (Netherlands)

    Swertz, Ch.A.

    1994-01-01

    The identification and classification of grass rust fungi is often difficult since most traditionally used morphological characters are quantitative and subjective. Besides, when using the host range as a taxonomic criterion, it is important to realize that a rust fungus may have jumped to a new hos

  10. Screening of New Resistance Sources of Wheat Leaf Rust%小麦叶锈病新抗源筛选

    Institute of Scientific and Technical Information of China (English)

    刘成; 闫红飞; 宫文萍; 李光蓉; 刘大群; 杨足君

    2013-01-01

    小麦叶锈病是小麦生产的主要病害之一,发病严重时往往导致大幅度减产.叶锈菌生理小种的变异易导致抗病基因抗性的丧失,因此不断获得新抗源对小麦抗病育种至关重要.小麦近缘植物中含有丰富的小麦育种所需的抗病基因.本研究从小麦-近缘植物双二倍体、附加系、代换系或易位系等创新种质中筛选出小麦叶锈病新抗源,为利用这些新抗源打下基础.苗期对116份供试材料人工接种美国堪萨斯州流行的小麦叶锈菌混合生理小种(Lrcomp),其中部分材料人工接种09-9-1441-1等5个中国当前流行的叶锈菌生理小种进行抗性鉴定,筛选获得新抗源.116份种质中,31份免疫、近免疫或高抗Lrcomp.含有希尔斯山羊草、尾状山羊草、拟斯卑尔脱山羊草、两芒山羊草、卵穗山羊草、沙融山羊草、柱穗山羊草、顶芒山羊草、小伞山羊草、偏凸山羊草、中间偃麦草、茸毛偃麦草、长穗偃麦草、粗穗披碱草、栽培黑麦、非洲黑麦、提莫菲维小麦染色质的部分种质免疫或高抗Lrcomp,而含二角山羊草、无芒山羊草、沙生冰草、多年生簇毛麦和1年生簇毛麦染色质的种质表现中感至高感Lrcomp.希尔斯山羊草4S染色体、尾状山羊草C#1和D#1染色体和两芒山羊草、顶芒山羊草中可能含有未被报道的抗Lr-comp的新基因,值得进一步向小麦转育.小麦-粗穗披碱草1HtS.1BL罗伯逊易位系对Lrcomp及09-9-1441-1和09-9-1426-1等5个中国当前流行叶锈菌生理小种近免疫,值得利用染色体工程等方法获得小片段抗病易位系应用于我国小麦抗叶锈育种.%Wheat leaf rust,one of the most major diseases of wheat,greatly reduce wheat yield when wheat cultivars are infected.It is important to continuously screen and obtain new resistance sources for wheat breeding due to the resistance losses caused by mutant of leaf rust races.Wheat-relatives harbor resistance

  11. Mycobacterial infections in striped bass from Delaware Bay

    Science.gov (United States)

    Ottinger, C.A.; Brown, J.J.; Densmore, Christine L.; Starliper, C.E.; Blazer, V.S.; Weyers, H.S.; Beauchamp, K.A.; Rhodes, M.W.; Kator, H.; Gauthier, David T.; Vogelbein, W.K.

    2007-01-01

    Eighty striped bass Morone saxatilis were obtained from Delaware Bay using commercial gill nets set adjacent to Woodland Beach (n = 70) and Bowers Beach (n = 10) in December 2003. Fish were examined for gross lesions. Total lengths (TLs) and eviscerated weights were determined to calculate condition factors (K). Portions of spleens were aseptically harvested for bacterial culture, and portions of spleens, kidneys (anterior and posterior), livers, and gonads were obtained for histological examination. The size distribution of the striped bass was relatively homogeneous; the mean TL was about 600 mm for all samples. Mean K exceeded 0.95 in all samples and was not significantly different (P > 0.05) among samples. Significant differences in mycobacterial infection prevalence (P ??? 0.05) were observed among samples; samples obtained at Woodland Beach (WB) on December 10 (53.8%, n = 13) and December 17 (7.1%, n = 42) exhibited the most striking differences in prevalence. Mycobacterial infection intensity ranged from 1 ?? 102 to 1 ?? 107 colony-forming units per gram of spleen. Acanthocephalan infection prevalence and intensity, non-acid-fast bacterial infection prevalence, and fish sex ratio were also significantly different among the samples (P ??? 0.05). Similar to the mycobacterial infections, differences in sex ratio, acanthocephalan infection, and non-acid-fast bacterial infection were observed between the WB samples taken on December 10 and 17. However, no significant associations (P > 0.05) were observed between sex ratio or these infections and mycobacterial infection. The differences in bacterial and parasite infection prevalence and intensity and fish sex ratio in some samples indicate that these fish had a different history and that the epizootiology of mycobacterial infection in striped bass from Delaware Bay may be relatively complex. ?? Copyright by the American Fisheries Society 2007.

  12. Behavior and Body Patterns of the Larger Pacific Striped Octopus.

    Directory of Open Access Journals (Sweden)

    Roy L Caldwell

    Full Text Available Over thirty years ago anecdotal accounts of the undescribed Larger Pacific Striped Octopus suggested behaviors previously unknown for octopuses. Beak-to-beak mating, dens shared by mating pairs, inking during mating and extended spawning were mentioned in publications, and enticed generations of cephalopod biologists. In 2012-2014 we were able to obtain several live specimens of this species, which remains without a formal description. All of the unique behaviors listed above were observed for animals in aquaria and are discussed here. We describe the behavior, body color patterns, and postures of 24 adults maintained in captivity. Chromatophore patterns of hatchlings are also shown.

  13. Behavior and Body Patterns of the Larger Pacific Striped Octopus.

    Science.gov (United States)

    Caldwell, Roy L; Ross, Richard; Rodaniche, Arcadio; Huffard, Christine L

    2015-01-01

    Over thirty years ago anecdotal accounts of the undescribed Larger Pacific Striped Octopus suggested behaviors previously unknown for octopuses. Beak-to-beak mating, dens shared by mating pairs, inking during mating and extended spawning were mentioned in publications, and enticed generations of cephalopod biologists. In 2012-2014 we were able to obtain several live specimens of this species, which remains without a formal description. All of the unique behaviors listed above were observed for animals in aquaria and are discussed here. We describe the behavior, body color patterns, and postures of 24 adults maintained in captivity. Chromatophore patterns of hatchlings are also shown.

  14. Sagittarius stream 3-d kinematics from SDSS Stripe 82

    OpenAIRE

    Koposov, Sergey E.; Belokurov, Vasily; Evans, N. Wyn

    2013-01-01

    Using multi-epoch observations of the Stripe 82 region done by Sloan Digital Sky Survey, we measure precise statistical proper motions of the stars in the Sagittarius stellar stream. The multi-band photometry and SDSS radial velocities allow us to efficiently select Sgr members and thus enhance the proper motion precision to ~0.1 mas/yr. We measure separately the proper motion of a photometrically selected sample of the main sequence turn-off stars, as well as of a spectroscopically selected ...

  15. Response to "Critical Assessment of the Evidence for Striped Nanoparticles".

    Directory of Open Access Journals (Sweden)

    Quy Khac Ong

    Full Text Available Stirling et al., (10.1371/journal.pone.0108482 presented an analysis on some of our publications on the formation of stripe-like domains on mixed-ligand coated gold nanoparticles. The authors shed doubts on some of our results however no valid argument is provided against what we have shown since our first publication: scanning tunneling microscopy (STM images of striped nanoparticles show stripe-like domains that are independent of imaging parameters and in particular of imaging speed. We have consistently ruled out the presence of artifacts by comparing sets of images acquired at different tip speeds, finding invariance of the stipe-like domains. Stirling and co-workers incorrectly analyzed this key control, using a different microscope and imaging conditions that do not compare to ours. We show here data proving that our approach is rigorous. Furthermore, we never solely relied on image analysis to draw our conclusions; we have always used the chemical nature of the particles to assess the veracity of our images. Stirling et al. do not provide any justification for the spacing of the features that we find on nanoparticles: ~1 nm for mixed ligand particles and ~ 0.5 nm for homoligand particles. Hence our two central arguments remain unmodified: independence from imaging parameters and dependence on ligand shell chemical composition. The paper report observations on our STM images; none is a sufficient condition to prove that our images are artifacts. We thoroughly addressed issues related to STM artifacts throughout our microscopy work. Stirling et al. provide guidelines for what they consider good STM images of nanoparticles, such images are indeed present in our literature. They conclude that the evidences we provided to date are insufficient, this is a departure from one of the authors' previous article which concluded that our images were composed of artifacts. Given that four independent laboratories have reproduced our measurements and

  16. Sonora exploratory study for the detection of wheat-leaf rust

    Science.gov (United States)

    Payne, R. W. (Principal Investigator)

    1980-01-01

    The applicability of LANDSAT remote sensing technology to the detection of a wheat-leaf-rust epidemic in Sonora, Mexico, during 1977 was investigated. LANDSAT data acquired during crop years 1975-76 and 1976-77 were clustered, classified, and analyzed in order to detect agricultural changes. Analysis of 1977 data indicates a significant proportion of the identified wheat is stressed (potentially rust-infected). Additional analyses show a significant increase in fallowing during the year, as well as a substantial decrease in reservoir levels in the Sonora agricultural region. Ground observations are required to substantiate these analyses. The possibility exists that heat-rust is not LANDSAT detectable and that the clusters identified as containing stressed signatures represent different varieties of wheat or perhaps nonwheat crops.

  17. Reflexion M\\"ossbauer analysis of the in situ oxidation products hydroxycarbonate green rust

    CERN Document Server

    Naille, Sebastien; Louber, Didier; Jean, Paul Moulin; Ruby, Christian; 10.1088/1742-6596/217/1/012084

    2010-01-01

    The purpose of this study is to determine the nature of the oxidation products of FeII-III hydroxycarbonate FeII4FeIII2(OH)12CO3~3H2O (green rust GR(CO32-)) by using the miniaturised M\\"ossbauer spectrometer MIMOS II. Two M\\"ossbauer measurements methods are used: method (i) with green rust pastes coated with glycerol and spread into Plexiglas sample holders, and method (ii) with green rust pastes in the same sample holders but introduced into a gas-tight cell with a beryllium window under a continuous nitrogen flow. Method (ii) allows us to follow the continuous deprotonation of GR(CO32-) into the fully ferric deprotonated form FeIII6O4(OH)8CO3~3H2O by adding the correct amount of H2O2, without any further oxidation or degradation of the samples.

  18. Is the striped mealybug, Ferrisia virgata, a vector of huanglongbing bacterium ‘Candidatus Liberibacter asiaticus’

    Science.gov (United States)

    This is the first report of ‘Ca. L. asiaticus’ (Las) present in striped mealybugs feeding on Las-infected periwinkle plants. In November 2010, specimens of a common greenhouse pest, the striped mealybug Ferrisia virgata (Cockerell) (Pseudococcidae; Hemiptera), were collected from Las-infected periw...

  19. Color Fringes Bordering Black Stripes at the Bottom of a Swimming Pool

    Science.gov (United States)

    Fuster, Gonzalo; Rojas, Roberto; Slüsarenko, Viktor

    2016-09-01

    We have observed a nice example of chromatic dispersion due to refraction in water, in the form of color fringes bordering the black stripes that exist at the bottom of a swimming pool. Here we give a qualitative description of the phenomenon, explaining the role of the black stripes and the dispersive index of refraction of water.

  20. Osmoregulatory effects of hypophysectomy and homologous prolactin replacement in hybrid striped bass

    DEFF Research Database (Denmark)

    Jackson, Leslie F; McCormick, Stephen D; Madsen, Steffen S;

    2005-01-01

    The effects of ovine prolactin (oPRL) and striped bass prolactin (sbPRL; Morone saxatilis) on plasma osmolality, electrolyte balance, and gill Na+,K+-ATPase activity were investigated in hypophysectomized (Hx), freshwater (FW)-acclimated, hybrid striped bass (M. saxatilis x Morone chrysops...

  1. First report of rust caused by Puccinia carduorum on Italian thistle in Tunisia

    Science.gov (United States)

    Italian thistle (Carduus pycnocephalus L.), family Asteraceae, is a common weed in rangelands, pasturelands, and cereal crops in Tunisia where it is rapidly spreading and becoming agriculturally important due to its competitive ability. It is also a problematic invasive weed in the western United S...

  2. Rust resistance in Arabic Coffee cultivars in northern Paraná

    Directory of Open Access Journals (Sweden)

    Leandro Del Grossi

    2013-02-01

    Full Text Available The objective of the study was to evaluate the resistance to rust in coffee cultivars developed by research institutes of Brazil in Paraná state. Resistance to the local leaf rust races was assessed in high disease intensity field conditions at Londrina and Congonhinhas in 2009 and 2010.The cultivars were developed by the EPAMIG/UFV, IAPAR, IAC and MAPA/Procafé. The resistant standard 'IAPAR 59' and the susceptible standards Catuaí Vermelho IAC 144' and 'Bourbon Amarelo' were used. A randomized block design with three replications and plots with 10 plants was used. A scale from 1 to 5 based on the rust intensity was used to evaluate the resistance. The Catiguá MG 1, Catiguá MG 2, IAPAR 59, IPR 98, IPR 104, Palma II, Paraíso H-419-10-6-2-5-1, Paraíso H-419-10-6-2-10-1, Paraíso H-419-10-6-2-12-1, Pau Brasil MG 1 and Sacramento MG 1 cultivars presented complete resistance to rust at Londrina and Congonhinhas. The cultivars derived from the Catucaí germplasm were susceptible or showed different levels of partial resistance. Partial resistance to the rust was observed in several coffees derived from "Hibrido de Timor". 'Acauã' and 'Obatã IAC 1669-20' presented complete resistance at Londrina, but at Congonhinhas, they were partially resistant, indicating that different rust races have occurred at these two locations.

  3. Annotation of a hybrid partial genome of the Coffee Rust (Hemileia vastatrix contributes to the gene repertoire catalogue of the Pucciniales

    Directory of Open Access Journals (Sweden)

    Marco Aurelio Cristancho

    2014-10-01

    Full Text Available Coffee leaf rust caused by the fungus Hemileia vastatrix is the most damaging disease to coffee worldwide. The pathogen has recently appeared in multiple outbreaks in coffee producing countries resulting in significant yield losses and increases in costs related to its control. New races/isolates are constantly emerging as evidenced by the presence of the fungus in plants that were previously resistant. Genomic studies are opening new avenues for the study of the evolution of pathogens, the detailed description of plant-pathogen interactions and the development of molecular techniques for the identification of individual isolates. For this purpose we sequenced 8 different H. vastatrix isolates using NGS technologies and gathered partial genome assemblies due to the large repetitive content in the coffee rust hybrid genome; 74.4% of the assembled contigs harbor repetitive sequences. A hybrid assembly of 333Mb was built based on the 8 isolates; this assembly was used for subsequent analyses.Analysis of the conserved gene space showed that the hybrid H. vastatrix genome, though highly fragmented, had a satisfactory level of completion with 91.94% of core protein-coding orthologous genes present. RNA-Seq from urediniospores was used to guide the de novo annotation of the H. vastatrix gene complement. In total, 14,445 genes organized in 3,921 families were uncovered; a considerable proportion of the predicted proteins (73.8% were homologous to other Pucciniales species genomes. Several gene families related to the fungal lifestyle were identified, particularly 483 predicted secreted proteins that represent candidate effector genes and will provide interesting hints to decipher virulence in the coffee rust fungus. The genome sequence of Hva will serve as a template to understand the molecular mechanisms used by this fungus to attack the coffee plant, to study the diversity of this species and for the development of molecular markers to distinguish

  4. Radiative striped wind model for gamma-ray bursts

    CERN Document Server

    Bégué, D; Lyubarski, Y

    2016-01-01

    In this paper we revisit the striped wind model in which the wind is accelerated by magnetic reconnection. In our treatment, radiation is included as an independent component, and two scenarios are considered. In the first one, radiation cannot stream efficiently through the reconnection layer, while the second scenario assumes that radiation is homogeneous in the striped wind. We show how these two assumptions affect the dynamics. In particular, we find that the asymptotic radial evolution of the Lorentz factor is not strongly modified whether radiation can stream through the reconnection layer or not. On the other hand, we show that the width, density and temperature of the reconnection layer are strongly dependent on these assumptions. We then apply the model to the gamma-ray burst context and find that photons cannot diffuse efficiently through the reconnection layer below radius $r_{\\rm D}^{\\Delta} \\sim 10^{10.5}$ cm, which is about an order of magnitude below the photospheric radius. Above $r_{\\rm D}^{\\...

  5. Rotationally driven 'zebra stripes' in Earth's inner radiation belt.

    Science.gov (United States)

    Ukhorskiy, A Y; Sitnov, M I; Mitchell, D G; Takahashi, K; Lanzerotti, L J; Mauk, B H

    2014-03-20

    Structured features on top of nominally smooth distributions of radiation-belt particles at Earth have been previously associated with particle acceleration and transport mechanisms powered exclusively by enhanced solar-wind activity. Although planetary rotation is considered to be important for particle acceleration at Jupiter and Saturn, the electric field produced in the inner magnetosphere by Earth's rotation can change the velocity of trapped particles by only about 1-2 kilometres per second, so rotation has been thought inconsequential for radiation-belt electrons with velocities of about 100,000 kilometres per second. Here we report that the distributions of energetic electrons across the entire spatial extent of Earth's inner radiation belt are organized in regular, highly structured and unexpected 'zebra stripes', even when the solar-wind activity is low. Modelling reveals that the patterns are produced by Earth's rotation. Radiation-belt electrons are trapped in Earth's dipole-like magnetic field, where they undergo slow longitudinal drift motion around the planet because of the gradient and curvature of the magnetic field. Earth's rotation induces global diurnal variations of magnetic and electric fields that resonantly interact with electrons whose drift period is close to 24 hours, modifying electron fluxes over a broad energy range into regular patterns composed of multiple stripes extending over the entire span of the inner radiation belt. PMID:24646996

  6. LONGITUDINALLY STRIPED FABRIC DESIGN WITH A MODIFIED WEIGHT

    Directory of Open Access Journals (Sweden)

    OANA Dorina

    2014-05-01

    Full Text Available There are cases when the mass of woven fabrics requiring amendment intervening in the internal structure of the fabric, the reason most often for economic reasons, but also for the diversification by look. The internal structure of striped fabric obtained by combining groups wire ties, densities and / or different fineness creates a specific case on change of fabric weight. Each stripe is a woven fabric whose features differ, in some cases significantly to the bars side by side. This is the reason why the change of mass of such a woven fabrics, it is not so simple as in the case of fabric with a uniform structure. Changing the whole of the fabric weight can be done by changing the mass of each partial woven fabrics.The proposed method for mass modification consists in identifying and determining the partial structural fabric components and their mass change. To change the mass densities chosen method which involves designing a woven fabrics with weft yarn density, so the fabric assembly reference model resulted in a new woven fabric with a mass change After studying the structural features of these fabrics, and methods used to design woven fabrics with weight change , it has been found that there are other ways to solve this problem they known by has can achieve the same results but the simplest way.

  7. Systemic sarcocystosis in a striped skunk (Mephitis mephitis).

    Science.gov (United States)

    Burcham, G N; Ramos-Vara, J A; Vemulapalli, R

    2010-05-01

    A striped skunk with neurological signs was euthanized and examined via necropsy. Histologically, protozoa were found in multiple tissues. Protozoal schizonts measured 15 to 25 mum in diameter and contained 4 to 6 mum crescent-shaped merozoites. Protozoa were associated with necrosis and inflammation in the lung, brain, liver, and nasal epithelium. Immunohistochemistry labeled protozoa strongly positive for Sarcocystis neurona. Polymerase chain reaction-amplified products from the protozoan were 99.6% identical to the corresponding portion of the nuclear small subunit ribosomal RNA gene of S neurona. S neurona origin was further confirmed by amplifying a 451-base pair DNA fragment from the skunk lung, which differed by just 2 or 3 base pairs from the small subunit ribosomal RNA gene of S neurona. Striped skunks act as intermediate and aberrant hosts for S neurona; however, S neurona has rarely been found in extraneural tissues in any species, and systemic sarcocystosis has not been reported in skunks. Additionally, canine distemper virus infection was confirmed with histopathology and immunohistochemistry. Concurrent canine distemper suggests that immunosuppression may have played a role in S neurona infection in this skunk. PMID:20375428

  8. Zebrafish stripes as a model for vertebrate colour pattern formation.

    Science.gov (United States)

    Singh, Ajeet Pratap; Nüsslein-Volhard, Christiane

    2015-01-19

    Colour patterns are prominent features of many animals and have important functions in communication, such as camouflage, kin recognition and mate choice. As targets for natural as well as sexual selection, they are of high evolutionary significance. The molecular mechanisms underlying colour pattern formation in vertebrates are not well understood. Progress in transgenic tools, in vivo imaging and the availability of a large collection of mutants make the zebrafish (Danio rerio) an attractive model to study vertebrate colouration. Zebrafish display golden and blue horizontal stripes that form during metamorphosis as mosaics of yellow xanthophores, silvery or blue iridophores and black melanophores in the hypodermis. Lineage tracing revealed the origin of the adult pigment cells and their individual cellular behaviours during the formation of the striped pattern. Mutant analysis indicated that interactions between all three pigment cell types are required for the formation of the pattern, and a number of cell surface molecules and signalling systems have been identified as mediators of these interactions. The understanding of the mechanisms that underlie colour pattern formation is an important step towards deciphering the genetic basis of variation in evolution. PMID:25602311

  9. Comparative severity of experimentally induced mycobacteriosis in striped bass Morone saxatilis and hybrid tilapia Oreochromis spp.

    Science.gov (United States)

    Wolf, J C; Smith, S A

    1999-11-30

    Twenty striped bass Morone saxatilis and 20 hybrid tilapia Oreochromis niloticus x O. mossambicus x O. aureus each received a single intramuscular injection of 1.6 x 10(6) colony forming units per gram body weight of Mycobacterium marinum. Striped bass manifested significantly greater clinical and microscopic disease compared to tilapia. Whereas all the striped bass had died or were clinically ill by Day 8 post-infection, there was no apparent disruption of normal behaviour, physical appearance, or growth in any of the sacrificed or surviving tilapia. Histologically, granulomas in striped bass were generally larger and less discrete, with a higher proportion of heavily vacuolated macrophages, and large cores of necrotic cells. Visceral granulomas in tilapia were smaller, with a higher proportion of epithelioid macrophages, more pigment-containing cells, more peripheral lymphocytes, and virtually no central necrosis. Visceral granulomas were 18-fold more numerous in striped bass than in tilapia. Based upon histomorphometric data, mean proportions of acid-fast bacteria within pronephros granulomas were 4-fold greater in striped bass than tilapia, and striped bass granulomas averaged more than twice as large as tilapia granulomas. In the anterior kidney of striped bass, a positive correlation existed between mean mycobacterial proportions and mean necrosis scores. In tilapia, mean mycobacterial proportions correlated negatively with mean granuloma numbers, whereas there was no correlation between these parameters in striped bass. Results suggest that intrinsic functional differences in the immunologic systems of striped bass and hybrid tilapia may contribute to inter-species variation in mycobacteriosis susceptibility. PMID:10686670

  10. Control of Fe(O,OH)6 nano-network structures of rust for high atmospheric-corrosion resistance

    International Nuclear Information System (INIS)

    A new-type of weathering steel containing 3.0 mass% Ni and 0.4 mass% Cu ('advanced weathering steel') exhibits good atmospheric-corrosion resistance in an atmosphere containing relatively high air-born salinity. Here, we show that the high performance was successfully achieved by controlling Fe(O,OH)6 nano-network structures of rust formed on their surfaces. A novel technique using synchrotron radiation has been developed for the in situ observation of rust-formation during wet-dry cycles. It has been revealed that the evolution of Fe(O,OH)6 nano-network structures of rust formed on the advanced weathering steel was more unique than those of conventional weathering steel and mild steel. At an early stage of reaction, Fe2NiO4 and CuO phases precipitate, which provide sites for the nucleation of the Fe(O,OH)6 nano-network resulting in the formation of rust composed of fine and dense-packed grains. The existence of Fe2NiO4 in the nano-network changes the ion-exchanging properties of rust from anion to cation selective. Then, the rust on the advanced weathering steel 'breathes out' chloride ions from the rust/steel interface, and protects steel for more than a century by reducing the life cycle maintenance cost in an environment-friendly manner

  11. Direct proof of static charge stripe correlations in La2-xBaxCuO4

    Science.gov (United States)

    Chen, X. M.; Thampy, V.; Mazzoli, C.; Barbour, A.; Gu, G.; Hill, J. P.; Tranquada, J. M.; Dean, M. P. M.; Wilkins, S. B.

    The nature of charge stripe order in the cuprates, and in particular whether the stripes are static or dynamic, is a key issue in understanding the relationship between stripes and superconductivity. In La2-xBaxCuO4 (LBCO) a low temperature structural distortion is widely believed to pin stripes into fixed, static domains, but such an assertion has never been directly verified. We performed resonant soft x-ray photon correlation spectroscopy (XPCS) to probe the charge order Bragg peak of 1/8 doped LBCO. At low temperatures, we observe time-independent x-ray speckle patterns persisting for more than three hours, proving the static nature of the stripes and we go on to discuss how stripe order melts with increasing temperature. Our results demonstrate that the combination of XPCS with diffraction limited light sources such as the National Synchrotron Light Source II can probe the dynamics of even subtle order parameters such as stripes in the cuprates. Work performed at Brookhaven National Laboratory was supported by the US Department of Energy, Division of Materials Science, under Contract No. DE-AC02-98CH10886. Use of the National Synchrotron Light Source II was supported under Contract No. DE-SC0012704.

  12. Quantitative Trait Loci for Resistance to Stripe Disease in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to map the quantitative trait loci for rice stripe resistance, a molecular linkage map was constructed based on the lines to rice stripe were investigated by both artificial inoculation at laboratory and natural infection in the field, and the ratios of ranged from 0 to 134.08 and from 6.25 to 133.6 under artificial inoculation at laboratory and natural infection in the field, respectively,and showed a marked bias towards resistant parent (Zhaiyeqing 8), indicating that the resistance to rice stripe was controlled by quantitative trait loci (QTL). QTL analysis showed that the QTLs detected by the two inoculation methods were completely different.Only one QTL, qSTV7, was detected under artificial inoculation, at which the Zhaiyeqing 8 allele increased the resistance to rice stripe, while two QTLs, qSTV5 and qSTV1, were detected under natural infection, in which resistant alleles came from Zhaiyeqing 8and Wuyujing 3, respectively. These results showed that resistant parent Zhaiyeqing 8 carried the alleles associated with the resistance to rice stripe virus and the small brown planthopper, and susceptible parent Wuyujing 3 also carried the resistant allele to rice stripe virus. In comparison with the results previously reported, QTLs detected in the study were new resistant genes to rice stripe disease. This will provide a new resistant resource for avoiding genetic vulnerability for single utilization of the resistant gene Stvb-i.

  13. Testing the thermal-niche oxygen-squeeze hypothesis for estuarine striped bass

    Science.gov (United States)

    Kraus, Richard T.; Secor, D.H.; Wingate, Rebecca L.

    2015-01-01

    In many stratified coastal ecosystems, conceptual and bioenergetics models predict seasonal reduction in quality and quantity of fish habitat due to high temperatures and hypoxia. We tested these predictions using acoustic telemetry of 2 to 4 kg striped bass (Morone saxatilis Walbaum) and high-resolution spatial water quality sampling in the Patuxent River, a sub-estuary of the Chesapeake Bay, during 2008 and 2009. Striped bass avoided hypoxic (dissolved oxygen ≤2 mg·l−1) subpycnocline waters, but frequently occupied habitats with high temperatures (>25 °C) in the summer months, as cooler habitats were typically not available. Using traditional concepts of the seasonal thermal-niche oxygen-squeeze, most of the Patuxent estuary would beconsidered unsuitable habitat for adult striped bass during summer. Application of a bioenergetics model revealed that habitats selected by striped bass during summer would support positive growth rates assuming fish could feed at one-half ofmaximum consumption. Occupancy of the estuary during summer by striped bass in this study was likely facilitated by sufficient prey and innate tolerance of high temperatures by sub-adult fish of the size range that we tagged. Our results help extend the thermalniche oxygen-squeeze hypothesis to native populations of striped bass in semi-enclosed coastal systems. Tolerance of for supraoptimal temperatures in our study supports recent suggestions by others that the thermal-niche concept for striped bass should be revised to include warmer temperatures.

  14. In situ hybridization for the detection of rust fungi in paraffin embedded plant tissue sections

    Science.gov (United States)

    Rust fungi infect a wide range of plant species making them of particular interest to plant pathologists. In order to study the interactions between these important pathogenic fungi and their host plants it is useful to be able to differentiate fungal tissue from plant tissue. This can be accomplish...

  15. Chromosome engineering to enhance utility of alien-derived stem rust resistance

    Science.gov (United States)

    In the past 50 years, a number of stem rust (Sr) resistance genes identified from wild relatives of wheat have been incorporated into wheat genomes through chromosome engineering. Some of these genes, including Sr25, Sr26, Sr32, Sr37, Sr39, Sr40, Sr43, Sr44, SrR, and three unnamed novel Sr genes fr...

  16. Analysis of the Lr34/Yr18 rust resistance region in wheat germplasm

    Science.gov (United States)

    An insertion/deletion size variant located at the csLV34 locus on chromosome 7D within an intron sequence of a sulphate transporter-like gene tightly linked to the Lr34/Yr18 dual rust resistance was used to examine a global collection of wheat cultivars, landraces and D genome containing diploid and...

  17. Association analysis identifies Melampsora ×columbiana poplar leaf rust resistance SNPs.

    Directory of Open Access Journals (Sweden)

    Jonathan La Mantia

    Full Text Available Populus species are currently being domesticated through intensive time- and resource-dependent programs for utilization in phytoremediation, wood and paper products, and conversion to biofuels. Poplar leaf rust disease can greatly reduce wood volume. Genetic resistance is effective in reducing economic losses but major resistance loci have been race-specific and can be readily defeated by the pathogen. Developing durable disease resistance requires the identification of non-race-specific loci. In the presented study, area under the disease progress curve was calculated from natural infection of Melampsora ×columbiana in three consecutive years. Association analysis was performed using 412 P. trichocarpa clones genotyped with 29,355 SNPs covering 3,543 genes. We found 40 SNPs within 26 unique genes significantly associated (permutated P<0.05 with poplar rust severity. Moreover, two SNPs were repeated in all three years suggesting non-race-specificity and three additional SNPs were differentially expressed in other poplar rust interactions. These five SNPs were found in genes that have orthologs in Arabidopsis with functionality in pathogen induced transcriptome reprogramming, Ca²⁺/calmodulin and salicylic acid signaling, and tolerance to reactive oxygen species. The additive effect of non-R gene functional variants may constitute high levels of durable poplar leaf rust resistance. Therefore, these findings are of significance for speeding the genetic improvement of this long-lived, economically important organism.

  18. Confocal microscopy of Spitzenkörper dynamics during growth and differentiation of rust fungi

    NARCIS (Netherlands)

    Dijksterhuis, J

    2003-01-01

    The membrane-selective fluorescent dye FM4-64, N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)py ridium dibromide, was used to stain the apical vesicle cluster within the specialized Spitzenkorper of the germ tube of the rust fungi Uromyces vignae and Puccinia graminis f. sp.

  19. Confocal microscopy of Spitzenkorper dynamics during growth and differentiation of rust fungi

    NARCIS (Netherlands)

    Dijksterhuis, J

    2003-01-01

    The membrane-selective fluorescent dye FM4-64, N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)py ridium dibromide, was used to stain the apical vesicle cluster within the specialized Spitzenkorper of the germ tube of the rust fungi Uromyces vignae and Puccinia graminis f. sp.

  20. Reaction to rust by a subset of sorghum accessions from Zimbabwe

    Science.gov (United States)

    Sorghum rust (Puccinia purpurea) is a foliar disease that affects sorghum productivity worldwide. The use of resistant sources is the most effective and stable way to control the disease. In this study, 68 sorghum accessions from the Zimbabwe collection maintained by the USDA-ARS, Plant Genetic Re...

  1. Virulence of wheat yellow rust races and resistance genes of wheat cultivars in Ecuador

    NARCIS (Netherlands)

    Ochoa, J.B.; Danial, D.L.; Paucar, B.

    2007-01-01

    Virulence factors of the yellow rust, Puccinia striiformis, populations in bread wheat were studied in Ecuador between 1973 and 2004. The number of virulence factors has increased markedly from very few in the early seventies to 16 at the end of the 90s. Isolates belonging to race 0E0 seem to be the

  2. Interrelations between citrus rust mite, Hirsutella thompsonii and greasy spot on citrus in Surinam

    NARCIS (Netherlands)

    Brussel, van E.W.

    1975-01-01

    Counts of citrus rust mite (Phyllocoptruta oleivora (Ashm.)) on leaves and fruit of citrus rose to a peak in the two dry seasons, the build up taking 4-5 weeks. It then decreased partly through infection by the entomogenous fungus Hirsutellathompsonii Fisher and partly through a decline in feed qual

  3. The formation of green rust induced by tropical river biofilm components

    Energy Technology Data Exchange (ETDEWEB)

    Jorand, F., E-mail: jorand@pharma.uhp-nancy.fr [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France); Zegeye, A. [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France); Ghanbaja, J. [Service Commun de Microscopies Electroniques et Microanalyses X (SCMEM), Nancy-Universite, Bvd des Aiguillettes, BP 239, 54506, Vandoeuvre-les-Nancy (France); Abdelmoula, M. [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France)

    2011-06-01

    In the Sinnamary Estuary (French Guiana), a dense red biofilm grows on flooded surfaces. In order to characterize the iron oxides in this biofilm and to establish the nature of secondary minerals formed after anaerobic incubation, we conducted solid analysis and performed batch incubations. Elemental analysis indicated a major amount of iron as inorganic compartment along with organic matter. Solid analysis showed the presence of two ferric oxides ferrihydrite and lepidocrocite. Bacteria were abundant and represented more than 10{sup 11} cells g{sup -1} of dry weight among which iron reducers were revealed. Optical and electronic microscopy analysis revealed than the bacteria were in close vicinity of the iron oxides. After anaerobic incubations with exogenous electron donors, the biofilm's ferric material was reduced into green rust, a Fe{sup II}-Fe{sup III} layered double hydroxide. This green rust remained stable for several years. From this study and previous reports, we suggest that ferruginous biofilms should be considered as a favorable location for GR biomineralization when redox conditions and electron donors availability are gathered. - Research highlights: {yields} Characterization of ferruginous biofilm components by solid analysis methods. {yields} Lepidocrocite and ferrihydrite were the main iron oxides. {yields} Anaerobic incubation of biofilm with electron donors produced green rust. {yields} Biofilm components promote the formation of the green rust. {yields} Ferruginous biofilm could contribute to the natural mercury attenuation.

  4. Nested Association Mapping of Stem Rust Resistance in Wheat Using Genotyping by Sequencing

    Science.gov (United States)

    Rouse, Matthew N.; Tsilo, Toi J.; Macharia, Godwin K.; Bhavani, Sridhar; Jin, Yue; Anderson, James A.

    2016-01-01

    We combined the recently developed genotyping by sequencing (GBS) method with joint mapping (also known as nested association mapping) to dissect and understand the genetic architecture controlling stem rust resistance in wheat (Triticum aestivum). Ten stem rust resistant wheat varieties were crossed to the susceptible line LMPG-6 to generate F6 recombinant inbred lines. The recombinant inbred line populations were phenotyped in Kenya, South Africa, and St. Paul, Minnesota, USA. By joint mapping of the 10 populations, we identified 59 minor and medium-effect QTL (explained phenotypic variance range of 1% – 20%) on 20 chromosomes that contributed towards adult plant resistance to North American Pgt races as well as the highly virulent Ug99 race group. Fifteen of the 59 QTL were detected in multiple environments. No epistatic relationship was detected among the QTL. While these numerous small- to medium-effect QTL are shared among the families, the founder parents were found to have different allelic effects for the QTL. Fourteen QTL identified by joint mapping were also detected in single-population mapping. As these QTL were mapped using SNP markers with known locations on the physical chromosomes, the genomic regions identified with QTL could be explored more in depth to discover candidate genes for stem rust resistance. The use of GBS-derived de novo SNPs in mapping resistance to stem rust shown in this study could be used as a model to conduct similar marker-trait association studies in other plant species. PMID:27186883

  5. Determination of Rate of Degradation of Iron Plates Due To Rust Using Image Processing -A Review

    Directory of Open Access Journals (Sweden)

    Priyanka Choudhary

    2014-03-01

    Full Text Available Abstract: most of industries and bridges around us make use of iron for manufacturing their products. On the other hand corrosion is a natural process that deteriorates the integrity of iron surface. Therefore, rusting of iron takes place. To avoid unwanted accidents in industries and bridges, it is necessary to detect rusting in earlier stage, so that it can be prevented. Digital image processing for the detection of the rusting provides fast, accurate and objectives results. In this research paper, we have done a systematic review of algorithms that help us to detect the rust area from a metal (iron.it has been found that most of researches are bring their images, processing series in usage for this purpose due to its simplicity in implementing and due to fact the images help capturing the visual inspection process easily and due to the ground teeth. The image processing techniques explored by other peoples based on in-depth analysis, we have also proposed a novel technique to overcome the limitation.

  6. Determination of Rate of Degradation of Iron Plates due to Rust using Image Processing

    Directory of Open Access Journals (Sweden)

    Priyanka Choudhary

    2015-02-01

    Full Text Available Most of industries and bridges around us make use of iron for manufacturing their products. On the other hand corrosion is a natural process that deteriorates the integrity of iron surface. Therefore, rusting of iron takes place. To avoid unwanted accidents in industries and bridges, it is necessary to detect rusting in earlier stage, so that it can be prevented. Digital image processing for the detection of the rusting provides fast, accurate and objectives results. In this research paper, we have done a systematic review of algorithms that help us to detect the rust area from a metal (iron.it has been found that most of researches are bring their images, processing series in usage for this purpose due to its simplicity in implementing and due to fact the images help capturing the visual inspection process easily and due to the ground teeth. The image processing techniques explored by other peoples based on in-depth analysis, we have also proposed a novel technique to overcome the limitation.

  7. Molecular mapping of leaf rust resistance genes in the wheat line Yu 356-9

    Institute of Scientific and Technical Information of China (English)

    HAN Liu-sha; LI Zai-feng; WANG Jia-zhen; SHI Ling-zhi; ZHU Lin; LI Xing; LIU Da-qun; Syed J A Shah

    2015-01-01

    The Chinese wheat line Yu 356-9 exhibits a high level of resistance to leaf rust. In order to decipher the genetic base of resistance in Yu 356-9, gene postulation, inheritance analyses, and chromosome linkage mapping were carried out. Gene postulation completed using 15 leaf rust pathotypes and 36 isogenic lines indicated that Yu 356-9 was resistant to al pathotypes tested. F1 and F2 plants from the cross Yu 356-9 (resistant)/Zhengzhou 5389 (susceptible) were tested with leaf rust pathotype“FHNQ”in the greenhouse. Results indicated a 3:1 segregation ratio, indicative of the presence of a single dominant leaf rust resistance gene in Yu 356-9 which was temporarily designated as LrYu. Bulk segregant analysis and molecular marker assays were used to map LrYu. Five simple sequence repeat (SSR) markers on chromosome 2BS were found closely linked to LrYu. Among these markers, Xwmc770 is the most closely linked, with a genetic distance of 5.7 cM.

  8. Search for partial resistance to leaf rust in a collection of ancient Spanish wheats

    NARCIS (Netherlands)

    Martinez, F.; Niks, R.E.; Moral, A.; Urbano, J.M.; Rubiales, D.

    2001-01-01

    A collection of 917 accessions of Spanish durum and bread wheat was screened for resistance to leaf rust (Puccinia triticina) under field conditions at three locations. Resistance levels ranged from very low to very high, high susceptibility being most frequent. Relative disease severity (referred t

  9. Histological, genetical and epidemiological studies on partial resistance in wheat to wheat leaf rust.

    NARCIS (Netherlands)

    Broers, L.H.M.; Jacobs, Th.

    1989-01-01

    Partial resistance (PR) of wheat to wheat leaf rust acted in two steps. The first step led to a reduced infection frequency (IF), the second step to a longer latency period (LP).The genes for a prolonged LP inherited in a recessive way and showed additive gene action. The PR-genotype Akabozu carried

  10. International testing of incomplete resistance against brown rust (Puccinia recondita) in IPHR wheat lines.

    NARCIS (Netherlands)

    Milliano, de W.A.J.; Beek, M.A.; Zadoks, J.C.

    1986-01-01

    Promising wheat lines from FAO's International Program for Horizontal Resistance (IPHR) in Brazil and Zambia were tested in the Netherlands against brown rust (Puccinia recondita. f.sp.tritici). Race nursery tests were performed on isolated field plots using five monopustular isolates from the Nethe

  11. Prehaustorial and posthaustorial resistance to wheat leaf rust in diploid wheat

    NARCIS (Netherlands)

    Anker, C.C.

    2001-01-01

    In modern wheat cultivars, resistance to wheat leaf rust, Puccinia triticina , is either based on hypersensitivity resistance or on partial resistance. Hypersensitivity resistance in wheat is monogenic, often complete and posthaustorial: it is induced after the formation of a haustorium by the patho

  12. High diversity of genes for nonhost resistance of barley to heterologous rust fungi

    NARCIS (Netherlands)

    Jafary, H.; Albertazzi, G.; Marcel, T.C.; Niks, R.E.

    2008-01-01

    Inheritance studies on the nonhost resistance of plants would normally require interspecific crosses that suffer from sterility and abnormal segregation. Therefore, we developed the barley¿Puccinia rust model system to study, using forward genetics, the specificity, number, and diversity of genes in

  13. Introgression of a New Stem Rust Resistance Gene from Aegilops markgrafii into Wheat

    Science.gov (United States)

    In a prior study, we reported that an Alcedo/Aegilops markgrafii disomic addition line, AIII(D) (2n=44), was resistant to three races of the Ug99 lineage and five North American races of stem rust pathogen in wheat and the resistance originated from the alien chromosome. In this study, our objectiv...

  14. Bipartite Ramsey numbers involving stars, stripes and trees

    Directory of Open Access Journals (Sweden)

    Michalis Christou

    2013-11-01

    Full Text Available The Ramsey number R(m, n is the smallest integer p such that any blue-red colouring of the edges of the complete graph Kp forces the appearance of a blue Km or a red Kn. Bipartite Ramsey problems deal with the same questions but the graph explored is the complete bipartite graph instead of the complete graph. We consider special cases of the bipartite Ramsey problem. More specifically we investigate the appearance of simpler monochromatic graphs such as stripes, stars and trees under a 2-colouring of the edges of a bipartite graph. We give the Ramsey numbers Rb(mP2, nP2, Rb(Tm, Tn, Rb(Sm, nP2, Rb(Tm, nP2 and Rb(Sm, Tn.

  15. Fermi-surface reconstruction by stripe order in cuprate superconductors

    Science.gov (United States)

    Laliberté, F.; Chang, J.; Doiron-Leyraud, N.; Hassinger, E.; Daou, R.; Rondeau, M.; Ramshaw, B.J.; Liang, R.; Bonn, D.A.; Hardy, W.N.; Pyon, S.; Takayama, T.; Takagi, H.; Sheikin, I.; Malone, L.; Proust, C.; Behnia, K.; Taillefer, Louis

    2011-01-01

    The origin of pairing in a superconductor resides in the underlying normal state. In the cuprate high-temperature superconductor YBa2Cu3Oy (YBCO), application of a magnetic field to suppress superconductivity reveals a ground state that appears to break the translational symmetry of the lattice, pointing to some density-wave order. Here we use a comparative study of thermoelectric transport in the cuprates YBCO and La1.8−xEu0.2SrxCuO4 (Eu-LSCO) to show that the two materials exhibit the same process of Fermi-surface reconstruction as a function of temperature and doping. The fact that in Eu-LSCO this reconstruction coexists with spin and charge modulations that break translational symmetry shows that stripe order is the generic non-superconducting ground state of hole-doped cuprates. PMID:21847106

  16. Structure-guided unidirectional variation de-striping in the infrared bands of MODIS and hyperspectral images

    Science.gov (United States)

    Zhang, Yaozong; Zhang, Tianxu

    2016-07-01

    Images taken using moderate resolution imaging spectroradiometer (MODIS) and hyperspectral imaging systems, especially in their infrared bands, usually lead to undesired stripe noises, which seriously affect the image quality. A variational de-striping model has been proven to have good performance, but knowing how to detect stripes effectively, especially to distinguish them from edges/textures, is still challenging. In this paper, a structure-guided unidirectional variational (SGUV) model that considers the structure of stripes is proposed. Because of the use of structure information, which textures and edges do not have, the proposed algorithm can effectively distinguish stripes from image textures and almost does not blur details while removing stripes. Comparative experiments based on real stripe images demonstrated that the proposed method provides optimal qualitative and quantitative results.

  17. Economic analysis of the proposed rule to prevent arrival of new genetic strains of the rust fungus Puccinia psidii in Hawai?i.

    Science.gov (United States)

    Burnett, Kimberly; D'Evelyn, Sean; Loope, Lloyd; Wada, Christopher A.

    2012-01-01

    Since its first documented introduction to Hawai‘i in 2005, the rust fungus P. psidii has already severely damaged Syzygium jambos (Indian rose apple) trees and the federally endangered Eugenia koolauensis (nioi). Fortunately, the particular strain has yet to cause serious damage to ‘ōhi‘a, which comprises roughly 80% of the state’s native forests and covers 400,000 ha. Although the rust has affected less than 5% of Hawaii’s ‘ōhi‘a trees thus far, the introduction of more virulent strains and the genetic evolution of the current strain are still possible. Since the primary pathway of introduction is Myrtaceae plant material imported from outside the state, potential damage to ‘ohi‘a can be minimized by regulating those high-risk imports. We discuss the economic impact on the state’s florist, nursery, landscaping, and forest plantation industries of a proposed rule that would ban the import of non-seed Myrtaceae plant material and require a one-year quarantine of seeds. Our analysis suggests that the benefits to the forest plantation industry of a complete ban on non-seed material would likely outweigh the costs to other affected sectors, even without considering the reduction in risk to ‘ōhi‘a. Incorporating the value of ‘ōhi‘a protection would further increase the benefit-cost ratio in favor of an import ban.

  18. Striped Bass Spawning in Non-Estuarine Portions of the Savannah River

    Energy Technology Data Exchange (ETDEWEB)

    Martin, D.; Paller, M.

    2007-04-17

    Historically, the estuarine portions of the Savannah River have been considered to be the only portion of the river in which significant amounts of striped bass (Morone saxatilis) spawning normally occur. A reexamination of data from 1983 through 1985 shows a region between River Kilometers 144 and 253 where significant numbers of striped bass eggs and larvae occur with estimated total egg production near that currently produced in the estuarine reaches. It appears possible that there are two separate spawning populations of striped bass in the Savannah River.

  19. Stem Rust Resistance in a Geographically Diverse Collection of Spring Wheat Lines Collected from Across Africa

    Science.gov (United States)

    Prins, Renée; Dreisigacker, Susanne; Pretorius, Zakkie; van Schalkwyk, Hester; Wessels, Elsabet; Smit, Corneli; Bender, Cornel; Singh, Davinder; Boyd, Lesley A.

    2016-01-01

    Following the emergence of the Ug99 lineage of Puccinia graminis f. sp. tritici (Pgt) a collective international effort has been undertaken to identify new sources of wheat stem rust resistance effective against these races. Analyses were undertaken in a collection of wheat genotypes gathered from across Africa to identify stem rust resistance effective against the Pgt races found in Eastern and Southern Africa. The African wheat collection consisted of historic genotypes collected in Kenya, South Africa, Ethiopia, Sudan, Zambia, Morocco, and Tunisia, and current South African breeding lines. Both Bayesian cluster and principal coordinate analyses placed the wheat lines from Sudan in a distinct group, but indicated a degree of genetic relatedness among the other wheat lines despite originating from countries across Africa. Seedling screens with Pgt race PTKST, pedigree information and marker haplotype analysis confirmed the presence of Sr2, Sr36, Sr24, Sr31, and Lr34/Yr18/Sr57 in a number of the lines. A genome-wide association study (GWAS) undertaken with Diversiry Arrays Technology (DArT) and stem rust (Sr) gene associated markers and Stem Area Infected (SAI) and Reaction Type (RT) field phenotypes, collected from trials carried out across two seasons in Kenya in 2009 and in South Africa in 2011, identified 29 marker-trait associations (MTA). Three MTA were in common between SAI and RT, with the biggest effect MTA being found on chromosome 6AS. Two wheat lines, W1406 and W6979 that exhibited high levels of adult plant stem rust resistance were selected to generate bi-parental mapping populations. Only the MTA on chromosomes 6AS and 3BS, and the locus Lr34/Yr18/Sr57 were confirmed following QTL mapping. Additional stem rust resistance QTL, not detected by the GWAS, were found on chromosomes 2BS, 2DL, 3DL, and 4D. PMID:27462322

  20. Pushing the boundaries of resistance: insights from Brachypodium-rust interactions

    Directory of Open Access Journals (Sweden)

    Melania eFigueroa

    2015-07-01

    Full Text Available The implications of global population growth urge transformation of current food and bioenergy production systems to sustainability. Members of the family Poaceae are of particular importance both in food security and for their applications as biofuel substrates. For centuries, rust fungi have threatened the production of valuable crops such as wheat, barley, oat and other small grains; similarly, biofuel crops can also be susceptible to these pathogens. Emerging rust pathogenic races with increased virulence and recurrent rust epidemics around the world point out the vulnerability of monocultures. Basic research in plant immunity, especially in model plants, can make contributions to understanding plant resistance mechanisms and improve disease management strategies. The development of the grass Brachypodium distachyon as a genetically tractable model for monocots, especially temperate cereals and grasses, offers the possibility to overcome the experimental challenges presented by the genetic and genomic complexities of economically valuable crop plants. The numerous resources and tools available in Brachypodium have opened new doors to investigate the underlying molecular and genetic bases of plant-microbe interactions in grasses and evidence demonstrating the applicability and advantages of working with B. distachyon is increasing. Importantly, several interactions between B. distachyon and devastating plant pathogens, such rust fungi, have been examined in the context of non-host resistance. Here, we discuss the use of B. distachyon in these various pathosystems. Exploiting B. distachyon to understand the mechanisms underpinning disease resistance to non-adapted rust fungi may provide effective and durable approaches to fend off these pathogens. The close phylogenetic relationship among Brachypodium spp. and grasses with industrial and agronomic value support harnessing this model plant to improve cropping systems and encourage its use in

  1. Pushing the boundaries of resistance: insights from Brachypodium-rust interactions.

    Science.gov (United States)

    Figueroa, Melania; Castell-Miller, Claudia V; Li, Feng; Hulbert, Scot H; Bradeen, James M

    2015-01-01

    The implications of global population growth urge transformation of current food and bioenergy production systems to sustainability. Members of the family Poaceae are of particular importance both in food security and for their applications as biofuel substrates. For centuries, rust fungi have threatened the production of valuable crops such as wheat, barley, oat, and other small grains; similarly, biofuel crops can also be susceptible to these pathogens. Emerging rust pathogenic races with increased virulence and recurrent rust epidemics around the world point out the vulnerability of monocultures. Basic research in plant immunity, especially in model plants, can make contributions to understanding plant resistance mechanisms and improve disease management strategies. The development of the grass Brachypodium distachyon as a genetically tractable model for monocots, especially temperate cereals and grasses, offers the possibility to overcome the experimental challenges presented by the genetic and genomic complexities of economically valuable crop plants. The numerous resources and tools available in Brachypodium have opened new doors to investigate the underlying molecular and genetic bases of plant-microbe interactions in grasses and evidence demonstrating the applicability and advantages of working with B. distachyon is increasing. Importantly, several interactions between B. distachyon and devastating plant pathogens, such rust fungi, have been examined in the context of non-host resistance. Here, we discuss the use of B. distachyon in these various pathosystems. Exploiting B. distachyon to understand the mechanisms underpinning disease resistance to non-adapted rust fungi may provide effective and durable approaches to fend off these pathogens. The close phylogenetic relationship among Brachypodium spp. and grasses with industrial and agronomic value support harnessing this model plant to improve cropping systems and encourage its use in translational

  2. Numerical Simulation of Thermal Striping Phenomena in a T-Junction Piping System Using Large Eddy Simulation

    Science.gov (United States)

    Tanaka, Masa-Aki; Ohshima, Hiroyuki; Monji, Hideaki

    At the Japan Atomic Energy Agency (JAEA), the simulation code “MUGTHES (MUlti Geometry simulation code for THErmal-hydraulic and Structure heat conduction analysis in boundary fitted coordinate)” has been developed to evaluate thermal striping phenomena that are caused by the turbulence mixing of fluids at different temperatures. In this paper, numerical schemes for thermal-hydraulic simulation employed in MUGTHES are described, including the LES model. A simple method to limit numerical oscillation is adopted in energy equation solutions. A new iterative method to solve the Poisson equation in the BFC system is developed for effective transient calculations. This method is based on the BiCGSTAB method and the SOR technique. As the code validation of MUGTHES, a numerical simulation in a T-junction piping system with the LES approach was conducted. Numerical results related to velocity and fluid temperature distributions were compared with existing water experimental data and the applicability of numerical schemes with the LES model in MUGTHES to the thermal striping phenomenon was confirmed.

  3. RR Lyrae stars in the SDSS Stripe 82 region: period-color and amplitude-color relations

    Science.gov (United States)

    Ngeow, C.-C.; Kanbur, S.; Bhardwaj, A.; Singh, H.

    2016-05-01

    Investigation of period-color (PC) and amplitude-color (AC) relations at the maximum and minimum light for RR Lyrae (RRL) stars can be used to probe the interaction of the hydrogen ionization front with photosphere at the atmosphere for this type of pulsating variables. For example, theoretical calculation indicated that such interaction would occur at the minimum light for RRL stars and caused a flat PC relation. In the past, the PC and AC relations have been investigated by using either the (V - R) or (V - I) colors. Here, we extend previous works to multi-bands by analyzing the RRL stars in SDSS (Sloan Digitized Sky Survey) Stripe 82 region, at which multi-epoch data are available for RRL stars located within the footprint of Stripe 82 region in ugriz bands. We present the PC and AC relations in four colors after correcting for extinction. We found that the structure of PC and AC relations for this sample of RRL stars is more complicated than a linear regression fit.

  4. SM-1蜡膜防锈油的研制%Preparation of SM-1 Rust Prevention Oil

    Institute of Scientific and Technical Information of China (English)

    谭胜; 付洪瑞; 陈学军; 刘东志

    2000-01-01

    以JD脂及酸和合成十八胺的复合物为成膜材料,制备了一种蜡膜防锈油。结果表明,该油具有油膜薄、防锈性好和油基稳定等特点,可用于机床、金属零备件及军械装备的封存与防护。%The SM-1 rust prevention oil was prepared by using complex of fatty acid and stearyl amine as basic film forming material, and a certain amount of oil soluble inhibitor was added. It was shown that the SM-1 rust prevention oil had favourite features in stability and rust prevention. It could be appropriate for sealing and rust preventing of machine tool, metal parts and ordnances.

  5. Control Efficacy of Common Fungicides against Yam Stripe Disease%常用杀菌剂防治山药斑纹病药效试验

    Institute of Scientific and Technical Information of China (English)

    舒锐; 焦健; 姚甜甜; 兰成云; 许念芳; 刘少军

    2015-01-01

    Yam stripe disease is one of the main diseases of yam, which causes the death of leaves and stems, and can also have a negative effect on the growth and yield of yam. Control efficacy of common fungicides against yam stripe disease was studied, and results showed that 75% chlorothalonil WP, 80% mancozeb WP and 50%thiram WP all had good effects on control against yam stripe disease.%山药斑纹病是危害山药生长的主要病害之一,造成山药叶片和蔓枯死,对山药生长及其产量造成了很大影响。试验通过采用多种常用杀菌剂对山药斑纹病进行防治试验,结果表明,百菌清75%可湿性粉剂、代森锰锌80%可湿性粉剂、福美双50%可湿性粉剂对山药斑纹病的防治效果最好,可在生产中推广使用。

  6. Contaminants in striped bass from the flint and Apalachicola Rivers 1986-1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Five striped bass (Morone saxitilis), collected between April 1986 and May 1989 from the Flint River at Albany, Georgia, and the Apalachicola River at...

  7. Striped Marlin (Tetrapturus audax) Hardparts and Gonads Collected by the PIRO Hawaii Longline Observer Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Compilation of all samples collected from striped marlin collected and brought to the Aiea Heights Research Facility by the PIRO Hawaii Longline Observer Program...

  8. Operational Plan and Environmental Assessment for Striped Skunk and Raccoon Management : Benton Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The action proposed in this plan is to trap and remove striped skunk and raccoon at Benton Lake National Wildlife Refuge. The purpose of the action is to manage,...

  9. Concerted action of two avirulent spore effectors activates Reaction to Puccinia graminis 1 (Rpg1)-mediated cereal stem rust resistance

    OpenAIRE

    Nirmala, Jayaveeramuthu; Drader, Tom; Lawrence, Paulraj K.; Yin, Chuntao; Hulbert, Scot; Steber, Camille M; Steffenson, Brian J.; Les J Szabo; von Wettstein, Diter; Kleinhofs, Andris

    2011-01-01

    The barley stem rust resistance gene Reaction to Puccinia graminis 1 (Rpg1), encoding a receptor-like kinase, confers durable resistance to the stem rust pathogen Puccinia graminis f. sp. tritici. The fungal urediniospores form adhesion structures with the leaf epidermal cells within 1 h of inoculation, followed by hyphae and haustorium formation. The RPG1 protein is constitutively expressed and not phosphorylated. On inoculation with avirulent urediniospores, it is phosphorylated in vivo wit...

  10. Propagation of dark stripe beams in nonlinear media: Snake instability and creation of optical vortices

    DEFF Research Database (Denmark)

    Mamaev, A.V.; Saffman, M.; Zozulya, A.A.

    1996-01-01

    We analyze the evolution of (1+1) dimensional dark stripe beams in bulk media with a photorefractive nonlinear response. These beams, including solitary wave solutions, are shown to be unstable with respect to symmetry breaking and formation of structure along the initially homogeneous coordinate....... Experimental results show the complete sequence of events starting from self-focusing of the stripe, its bending due to the snake instability, and subsequent decay into a set of optical vortices....

  11. Interpretation of FAENA and TIFFSS experiment : Comparison of temperature evaluation methods on thermal striping

    OpenAIRE

    笠原 直人; Yves LEJEAIL

    2000-01-01

    Since thermal striping is a coupled thermohydraulic and thermomechanical phenomenon, sodium mock-up tests were usually required to confirm structural integrity. CEA and JNC have developed evaluation procedures of thermal striping to establish design-by-analysis methodology for this phenomenon. In order to compare and to validate these methods, two benchmark problems were planned under EJCC contract. One of benchmarks provided by CEA is temperature and fatigue evaluation of tubes and plates te...

  12. Crisscrossed stripe order from interlayer tunneling in hole-doped cuprates

    OpenAIRE

    Maharaj, Akash V.; Hosur, Pavan; Raghu, S.

    2014-01-01

    Motivated by recent observations of charge order in the pseudogap regime of hole-doped cuprates, we show that {\\it crisscrossed} stripe order can be stabilized by coherent, momentum-dependent interlayer tunneling, which is known to be present in several cuprate materials. We further describe how subtle variations in the couplings between layers can lead to a variety of stripe ordering arrangements, and discuss the implications of our results for recent experiments in underdoped cuprates.

  13. High-Contrast Color-Stripe Pattern for Rapid Structured-Light Range Imaging

    CERN Document Server

    Je, Changsoo; Park, Rae-Hong

    2015-01-01

    For structured-light range imaging, color stripes can be used for increasing the number of distinguishable light patterns compared to binary BW stripes. Therefore, an appropriate use of color patterns can reduce the number of light projections and range imaging is achievable in single video frame or in "one shot". On the other hand, the reliability and range resolution attainable from color stripes is generally lower than those from multiply projected binary BW patterns since color contrast is affected by object color reflectance and ambient light. This paper presents new methods for selecting stripe colors and designing multiple-stripe patterns for "one-shot" and "two-shot" imaging. We show that maximizing color contrast between the stripes in one-shot imaging reduces the ambiguities resulting from colored object surfaces and limitations in sensor/projector resolution. Two-shot imaging adds an extra video frame and maximizes the color contrast between the first and second video frames to diminish the ambigui...

  14. Edge instability in a chiral stripe domain under an electric current and skyrmion generation

    Science.gov (United States)

    Lin, Shi-Zeng

    2016-07-01

    Motivated by the recent experimental observations on the skyrmion creation by cutting chiral stripe domains under a current drive [Jiang et al., Science 349, 283 (2015), 10.1126/science.aaa1442], we study the mechanism of skyrmion generation by simulating the dynamics of stripe domains. Our theory for skyrmion generation is based on the fact that there are two half skyrmions attached to the ends of a stripe domain. These half skyrmions move due to the coupling between the skyrmion topological charge and current. As a consequence, the stripe domain is bent or stretched depending on the direction of motion of the half skyrmions. For a large current, skyrmions are created by chopping the stripe domains via strong bending or stretching. Our theory provides an explanation to the experiments and is supported by the new experiments. Furthermore, we predict that skyrmions can also be generated using a Bloch stripe domain under a spin transfer torque which can be realized in B20 compounds.

  15. Kinetics of structural rust transformation in environments containing chloride and SO2

    Directory of Open Access Journals (Sweden)

    Valencia, A.

    2003-12-01

    Full Text Available The behavior of the rusts produced on low carbon steel exposed in industrial atmospheres, at different distances from the sea, was studied by simulating the wetting-drying cycle in a CEBELCOR type apparatus. Coupons electrode potential was monitored and rust layer was analyzed by gravimetric techniques, optical microscopy and Mössbauer spectroscopy. A particular chloride/sulfur ratio in the atmosphere was found, for which there is a particular behavior in rust formation. For this ratio, corrosion rates were much less than expected. It is postulated a kinetic mechanism for rust layer formation as the origin of this special behavior. An electrode potential similar to that in a weathering steel was observed, this is reflected in the low corrosion rate obtained. The proposed kinetic mechanism for rust formation under these exposure conditions enables new research lines on layer formation and the development of protective rust for industrial marine atmospheres.Se estudió el comportamiento de las herrumbres de un acero de bajo carbono expuesto en la simulación de atmósferas industriales con diferentes distancias al mar, con del ciclo de humectación y secado en el ensayo CEBELCOR y en soluciones representativas de las atmósferas en cuestión. Se hizo seguimiento del potencial de electrodo de los cuerpos de prueba y se analizó la capa de productos de corrosión por técnicas gravimétricas, microscopía óptica y espectroscopia Mössbauer. Se determinó un valor de cloruros y sulfatos en la atmósfera que genera un comportamiento particular en la formación de la herrumbre, presentando velocidades de corrosión menores a las esperadas para el tenor de agentes agresivos, y se postuló un mecanismo cinético en la formación de la película como causante del fenómeno particular. Se observó un comportamiento del potencial próximo al de un acero autoprotector, que se refleja en una menor velocidad de corrosión. La propuesta del mecanismo cin

  16. A study of the evolution of rust on Mo-Cu-bearing fire-resistant steel submitted to simulated atmospheric corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Hao Long [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Wencui Road 62, Shenyang 110016 (China); Zhang Sixun [College of Material and Metallurgy, Northeastern University, Wenhua Road 3, Shenyang 110004 (China); Technical Centre of Laiwu Steel Group, Ltd., Changsheng Road 23, Laiwu 271104 (China); Dong Junhua, E-mail: jhdong@imr.ac.cn [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Wencui Road 62, Shenyang 110016 (China); Ke Wei [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Wencui Road 62, Shenyang 110016 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer The rusting evolution of a Mo-Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated. Black-Right-Pointing-Pointer The rusting evolution of the steel is related to the rust composition, structure, and electrochemical characteristics. Black-Right-Pointing-Pointer Increased content of {alpha}-FeOOH and decreased {gamma}-FeOOH and Fe{sub 3}O{sub 4} indicate the enhanced resistance of the rust. Black-Right-Pointing-Pointer Mo and Cu are involved in the formation of molybdate and Cu(I)-bearing compounds in the rust. - Abstract: The corrosion evolution of a Mo-Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated by corrosion weight gain, XRD, EPMA, XPS, and polarization curves. The results indicate that the corrosion kinetics is closely related to the rust composition and electrochemical properties. As the corrosion proceeds, the relative content of {gamma}-FeOOH and Fe{sub 3}O{sub 4} decreases and {alpha}-FeOOH increases, and the rust layer becomes compact and adherent to steel substrate. Molybdenum and copper enrich in the inner rust layer, especially at the bottom of the corrosion nest, forming non-soluble molybdate and Cu(I)-bearing compounds responsible for enhanced corrosion resistance of the rust layer.

  17. A study of the evolution of rust on Mo–Cu-bearing fire-resistant steel submitted to simulated atmospheric corrosion

    International Nuclear Information System (INIS)

    Highlights: ► The rusting evolution of a Mo–Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated. ► The rusting evolution of the steel is related to the rust composition, structure, and electrochemical characteristics. ► Increased content of α-FeOOH and decreased γ-FeOOH and Fe3O4 indicate the enhanced resistance of the rust. ► Mo and Cu are involved in the formation of molybdate and Cu(I)-bearing compounds in the rust. - Abstract: The corrosion evolution of a Mo–Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated by corrosion weight gain, XRD, EPMA, XPS, and polarization curves. The results indicate that the corrosion kinetics is closely related to the rust composition and electrochemical properties. As the corrosion proceeds, the relative content of γ-FeOOH and Fe3O4 decreases and α-FeOOH increases, and the rust layer becomes compact and adherent to steel substrate. Molybdenum and copper enrich in the inner rust layer, especially at the bottom of the corrosion nest, forming non-soluble molybdate and Cu(I)-bearing compounds responsible for enhanced corrosion resistance of the rust layer.

  18. Draft Genome of the Wheat Rust Pathogen (Puccinia triticina) Unravels Genome-Wide Structural Variations during Evolution.

    Science.gov (United States)

    Kiran, Kanti; Rawal, Hukam C; Dubey, Himanshu; Jaswal, Rajdeep; Devanna, B N; Gupta, Deepak Kumar; Bhardwaj, Subhash C; Prasad, P; Pal, Dharam; Chhuneja, Parveen; Balasubramanian, P; Kumar, J; Swami, M; Solanke, Amolkumar U; Gaikwad, Kishor; Singh, Nagendra K; Sharma, Tilak Raj

    2016-01-01

    Leaf rust is one of the most important diseases of wheat and is caused by Puccinia triticina, a highly variable rust pathogen prevalent worldwide. Decoding the genome of this pathogen will help in unraveling the molecular basis of its evolution and in the identification of genes responsible for its various biological functions. We generated high quality draft genome sequences (approximately 100- 106 Mb) of two races of P. triticina; the variable and virulent Race77 and the old, avirulent Race106. The genomes of races 77 and 106 had 33X and 27X coverage, respectively. We predicted 27678 and 26384 genes, with average lengths of 1,129 and 1,086 bases in races 77 and 106, respectively and found that the genomes consisted of 37.49% and 39.99% repetitive sequences. Genome wide comparative analysis revealed that Race77 differs substantially from Race106 with regard to segmental duplication (SD), repeat element, and SNP/InDel characteristics. Comparative analyses showed that Race 77 is a recent, highly variable and adapted Race compared with Race106. Further sequence analyses of 13 additional pathotypes of Race77 clearly differentiated the recent, active and virulent, from the older pathotypes. Average densities of 2.4 SNPs and 0.32 InDels per kb were obtained for all P. triticina pathotypes. Secretome analysis demonstrated that Race77 has more virulence factors than Race 106, which may be responsible for the greater degree of adaptation of this pathogen. We also found that genes under greater selection pressure were conserved in the genomes of both races, and may affect functions crucial for the higher levels of virulence factors in Race77. This study provides insights into the genome structure, genome organization, molecular basis of variation, and pathogenicity of P. triticina The genome sequence data generated in this study have been submitted to public domain databases and will be an important resource for comparative genomics studies of the more than 4000 existing

  19. Essential oils for rust control on coffee plants Óleos essenciais no controle da ferrugem em cafeeiro

    Directory of Open Access Journals (Sweden)

    Ricardo Borges Pereira

    2012-02-01

    Full Text Available Rust is considered the most important disease in coffee because it causes severe defoliation in plants and, consequently, reduction in productivity. This study evaluated the in vitro effect of essential oils of cinnamon, citronella, lemongrass, clove, tea tree, thyme, neem and eucalyptus on the germination of urediniospores of Hemileia vastatrix; the effectiveness of these oils to control rust on seedlings of coffee cultivars Catucaí 2SL, Catuaí IAC 62 and Mundo Novo 379/19 in the greenhouse; and the effect of more promising oils on urediniospores of H. vastatrix by transmission electron microscopy (TEM. All the essential oils inhibited the germination of urediniospores with increasing concentrations. All oils promoted partial control of the disease in the greenhouse. However, the oils of thyme, clove and citronella, at a concentration of 1000 µL L-1, were most effective in controlling the disease on cultivars Catucaí 2SL, Catuaí IAC 62 and Mundo Novo 379/19, respectively. The images generated in TEM showed that urediniospores exposed to oils of clove, citronella and thyme promoted cellular disorganization and cytoplasmic vacuolization, which was more pronounced in urediniospores exposed to citronella oil. The oils of thyme, clove and citronella are promising for the control of rust in coffee.A ferrugem é considerada a doença de maior importância no cafeeiro, pois causa acentuada desfolha nas plantas e, consequentemente, redução na produtividade. Este trabalho avaliou o efeito in vitro de óleos essenciais de canela, citronela, capim-limão, cravo-da-índia, árvore-de-chá, tomilho, nim e eucalipto na germinação de urediniósporos de Hemileia vastatrix; a eficácia desses óleos no controle da ferrugem em mudas de cafeeiro das cultivares Catucaí 2SL, Catuaí IAC 62 e Mundo Novo 379/19 em casa de vegetação; e o efeito dos óleos mais promissores sobre urediniósporos de H. vastatrix por meio de microscopia eletrônica de transmiss

  20. Structural lability of Barley stripe mosaic virus virions.

    Directory of Open Access Journals (Sweden)

    Valentin V Makarov

    Full Text Available Virions of Barley stripe mosaic virus (BSMV were neglected for more than thirty years after their basic properties were determined. In this paper, the physicochemical characteristics of BSMV virions and virion-derived viral capsid protein (CP were analyzed, namely, the absorption and intrinsic fluorescence spectra, circular dichroism spectra, differential scanning calorimetry curves, and size distributions by dynamic laser light scattering. The structural properties of BSMV virions proved to be intermediate between those of Tobacco mosaic virus (TMV, a well-characterized virus with rigid rod-shaped virions, and flexuous filamentous plant viruses. The BSMV virions were found to be considerably more labile than expected from their rod-like morphology and a distant sequence relation of the BSMV and TMV CPs. The circular dichroism spectra of BSMV CP subunits incorporated into the virions, but not subunits of free CP, demonstrated a significant proportion of beta-structure elements, which were proposed to be localized mostly in the protein regions exposed on the virion outer surface. These beta-structure elements likely formed during virion assembly can comprise the N- and C-terminal protein regions unstructured in the non-virion CP and can mediate inter-subunit interactions. Based on computer-assisted structure modeling, a model for BSMV CP subunit structural fold compliant with the available experimental data was proposed.

  1. Early warning system for coffee rust disease based on error correcting output codes: a proposal

    Directory of Open Access Journals (Sweden)

    David Camilo Corrales

    2014-12-01

    Full Text Available Colombian coffee producers have had to face the severe consequences of the coffee rust disease since it was first reported in the country in 1983. Recently, machine learning researchers have tried to predict infection through classifiers such as decision trees, regression Support Vector Machines (SVM, non-deterministic classifiers and Bayesian Networks, but it has been theoretically and empirically demonstrated that combining multiple classifiers can substantially improve the classification performance of the constituent members. An Early Warning System (EWS for coffee rust disease was therefore proposed based on Error Correcting Output Codes (ECOC and SVM to compute the binary functions of Plant Density, Shadow Level, Soil Acidity, Last Nighttime Rainfall Intensity and Last Days Relative Humidity.

  2. A curious case of resistance to a new encounter pathogen: myrtle rust in Australia.

    Science.gov (United States)

    Tobias, Peri A; Guest, David I; Külheim, Carsten; Hsieh, Ji-Fan; Park, Robert F

    2016-06-01

    Resistance genes (R genes) in plants mediate a highly specific response to microbial pathogens, often culminating in localized cell death. Such resistance is generally pathogen race specific and believed to be the result of evolutionary selection pressure. Where a host and pathogen do not share an evolutionary history, specific resistance is expected to be absent or rare. Puccinia psidii, the causal agent of myrtle rust, was recently introduced to Australia, a continent rich in myrtaceous taxa. Responses within species to this new pathogen range from full susceptibility to resistance. Using the myrtle rust case study, we examine models to account for the presence of resistance to new encounter pathogens, such as the retention of ancient R genes through prolonged 'trench warfare', pairing of resistance gene products and the guarding of host integrity.

  3. The corrosion protection mechanism of rust converters: An electrochemical impedance spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Collazo, A. [ENCOMAT Group, ETSEI, Universidade de Vigo, Campus Universitario, 36310 Vigo (Spain); Novoa, X.R., E-mail: rnovoa@uvigo.e [ENCOMAT Group, ETSEI, Universidade de Vigo, Campus Universitario, 36310 Vigo (Spain); Perez, C.; Puga, B. [ENCOMAT Group, ETSEI, Universidade de Vigo, Campus Universitario, 36310 Vigo (Spain)

    2010-08-30

    Oxide converters represent an interesting alternative for the protection of steel surfaces that have some degree of rust. Although the mechanism of these converters is not clear, it is assumed that they react with iron oxides and generate new compounds that may have a passivation effect on the steel surface. This last point is not well established, and several authors have even spoken of an accelerating effect of these compounds. We present here a study of the electrochemical behaviour of iron oxides immersed in the rust converter. The modulus of the impedance increases significantly after a certain time of immersion, suggesting that the electronic conductivity and, consequently, the rate of the cathodic reaction tend to decrease.

  4. Histology and Ultrastructure of Transitional Changes in Skin Morphology in the Juvenile and Adult Four-Striped Mouse (Rhabdomys pumilio)

    OpenAIRE

    Eranée Stewart; Moyosore Salihu Ajao; Amadi Ogonda Ihunwo

    2013-01-01

    The four-striped mouse has a grey to brown coloured coat with four characteristic dark stripes interspersed with three lighter stripes running along its back. The histological differences in the skin of the juvenile and adult mouse were investigated by Haematoxylin and Eosin and Masson Trichrome staining, while melanocytes in the skin were studied through melanin-specific Ferro-ferricyanide staining. The ultrastructure of the juvenile skin, hair follicles, and melanocytes was also explored. I...

  5. How to make stripes: deciphering the transition from non-periodic to periodic patterns in Drosophila segmentation.

    Science.gov (United States)

    Schroeder, Mark D; Greer, Christina; Gaul, Ulrike

    2011-07-01

    The generation of metameric body plans is a key process in development. In Drosophila segmentation, periodicity is established rapidly through the complex transcriptional regulation of the pair-rule genes. The 'primary' pair-rule genes generate their 7-stripe expression through stripe-specific cis-regulatory elements controlled by the preceding non-periodic maternal and gap gene patterns, whereas 'secondary' pair-rule genes are thought to rely on 7-stripe elements that read off the already periodic primary pair-rule patterns. Using a combination of computational and experimental approaches, we have conducted a comprehensive systems-level examination of the regulatory architecture underlying pair-rule stripe formation. We find that runt (run), fushi tarazu (ftz) and odd skipped (odd) establish most of their pattern through stripe-specific elements, arguing for a reclassification of ftz and odd as primary pair-rule genes. In the case of run, we observe long-range cis-regulation across multiple intervening genes. The 7-stripe elements of run, ftz and odd are active concurrently with the stripe-specific elements, indicating that maternal/gap-mediated control and pair-rule gene cross-regulation are closely integrated. Stripe-specific elements fall into three distinct classes based on their principal repressive gap factor input; stripe positions along the gap gradients correlate with the strength of predicted input. The prevalence of cis-elements that generate two stripes and their genomic organization suggest that single-stripe elements arose by splitting and subfunctionalization of ancestral dual-stripe elements. Overall, our study provides a greatly improved understanding of how periodic patterns are established in the Drosophila embryo.

  6. Mass stranding of striped dolphin, Stenella coeruleoalba, at Augusta, Western Australia: notes on clinical pathology and general observations.

    Science.gov (United States)

    Gales, N J

    1992-10-01

    Seventeen striped dolphins, Stenella coeruleoalba, were found stranded on a West Australian beach. Three animals died before a rescue attempt was made and a further three died during the rescue. The remaining dolphins were released 24 km offshore and were not seen again. One dolphin was noted to have a broken mandible. Evidence of physical trauma to the other dolphins was minimal; one adult female was observed with some peeling skin. Blood was collected for analysis. All dolphins were slightly dehydrated and had a leukogram typical of a stressed animal. Plasma biochemistry reflected primary muscle trauma. There were no clues to the cause of the stranding; observed pathology reflected damage that occurred as a direct consequence of stranding. PMID:1474667

  7. Transcriptomic and metabolomic analyses identify a role for chlorophyll catabolism and phytoalexin during Medicago nonhost resistance against Asian soybean rust.

    Science.gov (United States)

    Ishiga, Yasuhiro; Uppalapati, Srinivasa Rao; Gill, Upinder S; Huhman, David; Tang, Yuhong; Mysore, Kirankumar S

    2015-08-12

    Asian soybean rust (ASR) caused by Phakopsora pachyrhizi is a devastating foliar disease affecting soybean production worldwide. Understanding nonhost resistance against ASR may provide an avenue to engineer soybean to confer durable resistance against ASR. We characterized a Medicago truncatula-ASR pathosystem to study molecular mechanisms of nonhost resistance. Although urediniospores formed appressoria and penetrated into epidermal cells of M. truncatula, P. pachyrhizi failed to sporulate. Transcriptomic analysis revealed the induction of phenylpropanoid, flavonoid and isoflavonoid metabolic pathway genes involved in the production of phytoalexin medicarpin in M. truncatula upon infection with P. pachyrhizi. Furthermore, genes involved in chlorophyll catabolism were induced during nonhost resistance. We further characterized one of the chlorophyll catabolism genes, Stay-green (SGR), and demonstrated that the M. truncatula sgr mutant and alfalfa SGR-RNAi lines showed hypersensitive-response-like enhanced cell death upon inoculation with P. pachyrhizi. Consistent with transcriptomic analysis, metabolomic analysis also revealed the accumulation of medicarpin and its intermediate metabolites. In vitro assay showed that medicarpin inhibited urediniospore germination and differentiation. In addition, several triterpenoid saponin glycosides accumulated in M. truncatula upon inoculation with P. pachyrhizi. In summary, using multi-omic approaches, we identified a correlation between phytoalexin production and M. truncatula defense responses against ASR.

  8. Major transcriptome reprogramming underlies floral mimicry induced by the rust fungus Puccinia monoica in Boechera stricta.

    Directory of Open Access Journals (Sweden)

    Liliana M Cano

    Full Text Available Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P. monoica-induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments and terpenoid biosynthesis (major floral volatile compounds were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry.

  9. Resistance to leaf rust in coffee carrying S H3 gene and others S H genes

    Directory of Open Access Journals (Sweden)

    Gustavo Hiroshi Sera

    2007-09-01

    Full Text Available The aim of this work was to evaluate the resistance to rust in coffee carrying S H3 gene and other S H genes. Twenty one CIFC’s coffee trees with several resistance genes S H were evaluated in field conditions. All the evaluated coffees carrying Sh3 gene presented resistance to the rust. It was possible that rust races with the virulence gene v3 in the Paraná State didn’t exist. The S H3 gene in combination with genes S H5, S H6, S H7, S H8, S H9 and S H? would be very important to obtain cultivars with more durable resistance to the rust.O objetivo deste trabalho foi avaliar a resistência à ferrugem em cafeeiros portadores do gene S H3 e outros genes S H em Londrina, Paraná, Brasil. Foram avaliados vinte e um cafeeiros do CIFC com diferentes genes S H de resistência em condição de alta incidência natural em campo. Todos os cafeeiros avaliados portadores do gene S H3 apresentaram resistência à ferrugem. É possível que não existam raças de ferrugem com o gene de virulência v3 no Paraná. Plantas portadoras do gene S H3 em combinação com os genes S H5, S H6, S H7, S H8, S H9 e S H? seria muito importante para obter cultivares com resistência mais durável à ferrugem.

  10. Efficient dechlorination of carbon tetrachloride by hydrophobic green rust intercalated with dodecanoate anions

    DEFF Research Database (Denmark)

    Ayala Luis, Karina Barbara; Ginette Anneliese Cooper, Nicola; Bender Koch, Christian;

    2012-01-01

    The reductive dechlorination of carbon tetrachloride (CT) by Fe-II-Fe-III hydroxide (green rust) intercalated with dodecanoate, (Fe4Fe2III)-Fe-II (OH)(12)(C12H23O2)(2)center dot gamma H2O (designated GR(C12)), at pH similar to 8 and at room temperature was investigated. CT at concentration levels...

  11. IPR 107 – Dwarf arabic coffee cultivar with resistance to coffee leaf rust

    Directory of Open Access Journals (Sweden)

    Tumoru Sera

    2013-01-01

    Full Text Available ‘IPR 107’ was derived from a cross between ‘IAPAR 59’ and ‘Mundo Novo IAC 376-4’. ‘IPR 107’ is a dwarf medium sizeplant with medium precocity in ripening and with complete resistance to rust races in this time. This cultivar presents superior qualityand high yield in many coffee regions.

  12. Resistance against barley leaf rust (Puccinia hordei) in West-European spring barley germplasm

    OpenAIRE

    Niks, Rients; Walther, Ursula; Jaiser, Heidi; Martinez, Fernando; Rubiales, Diego

    2000-01-01

    International audience The level and type of resistance against leaf rust (Puccinia hordei) was determined in modern spring barley germplasm. In field trials all over Europe most accessions were in some locations and years significantly less infected than the moderately resistant reference ,Grit'. Differentiating P. hordei isolates indicated that most accessions carried hypersensitivity (Rph) genes. A virulence survey indicated that among the known resistance genes, only Rph7 is still full...

  13. Analysis and modelling of effects of leaf rust and Septoria tritici blotch on wheat growth.

    Science.gov (United States)

    Robert, Corinne; Bancal, Marie-Odile; Nicolas, Pierre; Lannou, Christian; Ney, Bertrand

    2004-05-01

    A model to predict Septoria tritici blotch (STB) and leaf rust effects on wheat growth was constructed and evaluated in two steps. At the leaf scale, Bastiaans' approach that predicts the relative photosynthesis of a wheat leaf infected with a single disease, was extended to the case of two diseases, one biotrophic and one necrotrophic by considering the leaf rust-STB complex. A glasshouse experiment with flag leaves inoculated either singly with one disease or with two diseases combined was performed to check the leaf damage model. No interaction of the two diseases on photosynthesis loss was observed when they occurred simultaneously on the same leaf. In a second step, the single-leaf model was extended to the canopy scale to model the effects of the leaf rust-STB complex on the growth of a wheat crop. The model predicts the effects of disease on the growth of an affected crop relative to the growth of a healthy crop. The canopy model accounted for different contributions to photosynthetic activity of leaf layers, derived from their position in the canopy and their natural leaf senescence. Treatments differing in nitrogen fertilization, microclimatic conditions, and wheat cultivars were implemented in a field experiment to evaluate the model. The model accurately estimated the effect of disease on crop growth for each cultivar, with differences from experimental values lower than 10%, which suggests that this model is well suited to aid an understanding of disease effects on plant growth. A reduction in green leaf area was the main effect of disease in these field experiments and STB accounted for more than 70% of the reduction in plant growth. Simulations suggested that the production of rust spores may result in a loss of biomass from diseased crops and that stem photosynthesis may need to be considered in modelling diseased crop growth.

  14. Role of micronutrients in defense to white rust and Alternaria blight infecting Indian mustard.

    Science.gov (United States)

    Rathi, A S; Singh, Dhiraj; Avtar, Ram; Kumar, Pawan

    2015-03-01

    Field experiments were carried out at Oilseeds Research Area of CCS Haryana Agricultural University, Hisar during rabi, 2008-09 to 2011-12 to find out the possible role of soil application of different micronutrients alone and in combinations in defense to white rust and Alternaria blight diseases in Indian mustard [Brassica juncea (L.) Czern & Coss.]. Among the sole application of micronutrients, minimum disease severity of both white rust (35.0%) and Alternaria blight (31.8%) was observed when S @ 40 kg ha in the form of Gypsum was applied as basal dose in the soil. When Gypsum was supplemented with Borax @10 kg ha(-1) or with ZnSO4 @15 kg ha(-1) the level of tolerance seems to be improved for both the diseases as compared to the sole treatment of each nutrient, i.e., ZnSO4 @ 15 kg/ha, Borax @ 10 kg ha' and Gypsum @ 250 kg ha(-1). Furthermore, minimum disease severity of both white rust (31.3 %) and Alternaria blight (26.3 %) was observed with soil application of ZnSO4 @ 15 kg ha(-1) + Borax @ 10 kg ha(-1) + Gypsum @250 kg ha(-1) as basal dose as compared to the severity of white rust (43.6%) and Alternaria blight (38.6%) in untreated check. Significant increase in seed yield (1612 kg ha(-1)) was also recorded in above mentioned treatment as compared to the yield (1337 kg ha(-1)) in untreated check. These findings will also be helpful in maintaining soil health and minimizing the losses due to both the fungal diseases for eco-friendly sustainability of Indian mustard.

  15. Analysis on Abrasive Selection and De-rust Quality and Cost%磨料选择与船舶除锈质量及成本分析

    Institute of Scientific and Technical Information of China (English)

    丁霞琴; 孔德陆

    2014-01-01

    分析不同种类磨料对船舶除锈质量及成本的影响,介绍几种典型磨料表面处理的清洁效果和消耗性试验的结果,分析钢砂磨料在船舶除锈中的作用,提出在PSPC标准下合金钢砂的正确运用以及选择钢砂的建议。%Different abrasive will directly affect the de-rust quality and cost of shipbuilding .The experimental results of cleaning surface and consumption caused by different abrasive was introduced .The result showed that steel grit abrasive is excel-lent.Some suggestions of how to use alloy-grit correctly were put forward ccording to PSPC requirement .

  16. Scaphoid and pronator fat stripes are unreliable soft tissue signs in the detection of radiographically occult fractures

    Energy Technology Data Exchange (ETDEWEB)

    Annamalai, G.; Raby, N. E-mail: n.raby@clinmed.gla.ac.uk

    2003-10-01

    AIM: To determine the clinical value of scaphoid and pronator fat stripes in identifying occult underlying scaphoid and distal radius fractures, respectively. MATERIALS AND METHODS: In our department, all patients with clinically suspected scaphoid fractures and normal scaphoid series of radiographs undergo magnetic resonance imaging (MRI) of the wrist. We selected 50 cases with unequivocal MRI evidence of scaphoid fracture, 50 cases with distal radius fracture and 50 cases with no MRI evidence of bony injury. All 150 initial plain radiographs were examined retrospectively in random order without knowledge of the MRI findings and the scaphoid and pronator fat stripes scrutinized. RESULTS: The scaphoid fat stripe was abnormal in only 25 cases (50%) with confirmed scaphoid fracture on MRI. The pronator fat stripe was abnormal in 13 cases (26%) with confirmed distal radius fracture. In the 50 cases with no MRI evidence of bony injury, the scaphoid fat stripe and pronator fat stripe were abnormal in 25 (50%) and 15 (30%) cases, respectively. The sensitivity and specificity for an abnormal scaphoid fat stripe was 50%. The sensitivity and specificity for an abnormal pronator fat stripe was 26 and 70%, respectively. CONCLUSION: Scaphoid and pronator fat stripes are poor predictors of the presence or absence of underlying occult fractures.

  17. Cryptosexuality and the genetic diversity paradox in coffee rust, Hemileia vastatrix.

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Carvalho

    Full Text Available BACKGROUND: Despite the fact that coffee rust was first investigated scientifically more than a century ago, and that the disease is one of the major constraints to coffee production--constantly changing the socio-economic and historical landscape of the crop--critical aspects of the life cycle of the pathogen, Hemileia vastatrix, remain unclear. The asexual urediniospores are regarded as the only functional propagule: theoretically, making H. vastatrix a clonal species. However, the well-documented emergence of new rust pathotypes and the breakdown in genetic resistance of coffee cultivars, present a paradox. METHODS AND RESULTS: Here, using computer-assisted DNA image cytometry, following a modified nuclear stoichiometric staining technique with Feulgen, we show that meiosis occurs within the urediniospores. Stages of spore development were categorised based on morphology, from the spore-mother cell through to the germinating spore, and the relative nuclear DNA content was quantified statistically at each stage. CONCLUSIONS: Hidden sexual reproduction disguised within the asexual spore (cryptosexuality could explain why new physiological races have arisen so often and so quickly in Hemileia vastatrix. This could have considerable implications for coffee breeding strategies and may be a common event in rust fungi, especially in related genera occupying the same basal phylogenetic lineages.

  18. Transfer of genes for stem rust resistance from Agropyron elongatum and imperial rye to durum wheat

    International Nuclear Information System (INIS)

    The Agropyron elongatum gene for stem rust resistance on chromosome 6A of Knott's Thatcher translocation line was transferred to a susceptible local durum wheat variety, Jaya, through a series of back-crosses. Plants heterozygous for the Agropyron translocation always show at least one open bivalent. Homozygotes have not been obtained, probably because of the absence of male transmission in durum background. Monotelosomic addition of the short arm of Imperial rye chromosome 3R (formerly ''G'' of Sears), which carries a gene(s) for resistance to wheat stem rust, was obtained in the local durum variety. Rust-resistant plants from parents having the added rye telocentric were irradiated with gamma rays just before meiosis, and the pollen obtained from the irradiated spikes was used to pollinate euploid plants. In addition, seeds harvested from 2n+1 resistant plants were irradiated with thermal neutrons and the resistant M1 plants were selfed to raise M2 families. Two durum-rye translocation lines were obtained following irradiation. DRT-1 was transmitted normally through the female gametes but showed no male transmission. As a result of this, homozygotes have not been obtained. Gametic transmission rates of DRT-2 are being tested. Alien translocations, which show normal gametic and zygotic transmissions in the hexaploid wheat, may behave differently in a tetraploid background. The results indicate that alien genetic transfers may be more difficult to obtain in durum wheat, probably owing to the reduced buffering effect of the tetraploid genome. (author)

  19. Effector-mining in the poplar rust fungus Melampsora larici populina secretome

    Directory of Open Access Journals (Sweden)

    Cecile eLorrain

    2015-12-01

    Full Text Available The poplar leaf rust fungus, Melampsora larici-populina has been established as a tree-microbe interaction model. Understanding the molecular mechanisms controlling infection by pathogens appears essential for durable management of tree plantations. In biotrophic plant parasites, effectors are known to condition host cell colonization. Thus, investigation of candidate secreted effector proteins is a major goal in the poplar-poplar rust interaction. Unlike oomycetes, fungal effectors do not share conserved motifs and candidate prediction relies on a set of a priori criteria established from reported bona fide effectors. Secretome prediction, genome-wide analysis of gene families and transcriptomics of M. larici-populina have led to catalogues of more than a thousand secreted proteins. Automatized effector mining pipelines hold great promise for rapid and systematic identification and prioritization of candidate secreted effector proteins for functional characterization. In this review, we report on and discuss the current status of the poplar rust fungus secretome and prediction of candidate effectors in this species.

  20. Exploring the role of asexual multiplication in poplar rust epidemics: impact on diversity and genetic structure.

    Science.gov (United States)

    Barrès, Benoît; Dutech, Cyril; Andrieux, Axelle; Halkett, Fabien; Frey, Pascal

    2012-10-01

    Fungal plant pathogens, especially rust fungi (Pucciniales), are well known for their complex life cycles, which include phases of sexual and asexual reproduction. The effect of asexual multiplication on population genetic diversity has been investigated in the poplar rust fungus Melampsora larici-populina using a nested hierarchical sampling scheme. Four hierarchical levels were considered: leaf, twig, tree and site. Both cultivated and wild poplar stands were sampled at two time points at the start and end of rust epidemics. A total of 641 fungal isolates was analysed using nine microsatellite markers. This study revealed that the genetic signature of asexual multiplication in the wild poplar stand was seen only at lower hierarchical levels (leaf and twig). Moreover, we observed an erosion of clonal structure through time, with an increase in both gene and genotypic diversity. New genotypes contributed to host infection over time, which demonstrates the importance of allo-infection in the epidemic process in this host-pathogen system. Compared with the wild stands, the nearly lack of detection of clonal structure in the cultivated stands reflects the higher infection level on cultivated poplars. More generally, this genetic analysis illustrates the utility of population genetics approach for elucidating the proportion of asexual reproduction in the multiplication of isolates during an epidemic, and for proper quantification of asexual dispersal in plant pathogens.