WorldWideScience

Sample records for causing stripe rust

  1. Wheat Stripe Rust

    OpenAIRE

    Pace, Mike; Israelsen, Clark; Evans, Kent; Barnhill, James

    2008-01-01

    Stripe rust, or yellow rust, is primarily a foliar fungal disease of wheat, although it can infect spike and stem tissues. If the pathogen infects the spike (head) it causes extensive quality and grain yield loss. The disease is caused by the fungus Puccinia striiformis f. sp. tritici. The fungus can only survive and reproduce on wheat. It survives from one season to the next on volunteer plants.

  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

    Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based...... 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...... that wheat rust fungi can adapt to warmer temperatures and cause severe disease in previously unfavorable environments...

  3. Physical Localization of a Locus from Agropyron cristatum Conferring Resistance to Stripe Rust in Common Wheat.

    Science.gov (United States)

    Zhang, Zhi; Song, Liqiang; Han, Haiming; Zhou, Shenghui; Zhang, Jinpeng; Yang, Xinming; Li, Xiuquan; Liu, Weihua; Li, Lihui

    2017-11-13

    Stripe rust, caused by Puccinia striiformis f. sp. tritici ( Pst ), is one of the most destructive diseases of wheat ( Triticum aestivum L.) worldwide. Agropyron cristatum (L.) Gaertn. (2 n = 28, PPPP), one of the wild relatives of wheat, exhibits resistance to stripe rust. In this study, wheat- A . cristatum 6P disomic addition line 4844-12 also exhibited resistance to stripe rust. To identify the stripe rust resistance locus from A . cristatum 6P, ten translocation lines, five deletion lines and the BC₂F₂ and BC₃F₂ populations of two wheat- A . cristatum 6P whole-arm translocation lines were tested with a mixture of two races of Pst in two sites during 2015-2016 and 2016-2017, being genotyped with genomic in situ hybridization (GISH) and molecular markers. The result indicated that the locus conferring stripe rust resistance was located on the terminal 20% of 6P short arm's length. Twenty-nine 6P-specific sequence-tagged-site (STS) markers mapped on the resistance locus have been acquired, which will be helpful for the fine mapping of the stripe rust resistance locus. The stripe rust-resistant translocation lines were found to carry some favorable agronomic traits, which could facilitate their use in wheat improvement. Collectively, the stripe rust resistance locus from A . cristatum 6P could be a novel resistance source and the screened stripe rust-resistant materials will be valuable for wheat disease breeding.

  4. substitution line for resistance to stripe rust

    Indian Academy of Sciences (India)

    2011-08-19

    Aug 19, 2011 ... c Indian Academy of Sciences. RESEARCH ARTICLE. Molecular cytogenetic characterization of a new wheat Secale africanum. 2R a. (2D) substitution line for resistance to stripe rust. MENGPING LEI, GUANGRONG LI, SUFEN ZHANG, CHENG LIU and ZUJUN YANG. ∗. School of Life Science and ...

  5. Mapping genes for resistance to stripe rust in spring wheat landrace PI 480035

    Science.gov (United States)

    Stripe rust caused by Puccinia striiformis Westend. f. sp. tritici Erikks. is an economically important disease of wheat (Triticum aestivum L.). Hexaploid spring wheat landrace PI 480035 was highly resistant to stripe rust in the field in Washington during 2011 and 2012. The objective of this resear...

  6. leaf and stripe rust resistance among ethiopian grown wheat ...

    African Journals Online (AJOL)

    ADMIN

    pathogen pathotypes. These varieties and lines, therefore, may be utilized in leaf and stripe rust resistance breeding programs. Key words/phrases: Leaf rust, resistance, stripe rust, Triticum aestivum, Triticum turgidum. * Current address: University of Limpopo, School of Agricultural and Environmental Sciences, Private Bag ...

  7. Identification and mapping of leaf, stem and stripe rust resistance quantitative trait loci and their interactions in durum wheat

    OpenAIRE

    Singh, A.; Pandey, M. P.; Singh, A. K.; Knox, R. E.; Ammar, K.; Clarke, J. M.; Clarke, F. R.; Singh, R. P.; Pozniak, C. J.; DePauw, R. M.; McCallum, B. D.; Cuthbert, R. D.; Randhawa, H. S.; Fetch, T. G.

    2012-01-01

    Leaf rust (Puccinia triticina Eriks.), stripe rust (Puccinia striiformis f. tritici Eriks.) and stem rust (Puccinia graminis f. sp. tritici) cause major production losses in durum wheat (Triticum turgidum L. var. durum). The objective of this research was to identify and map leaf, stripe and stem rust resistance loci from the French cultivar Sachem and Canadian cultivar Strongfield. A doubled haploid population from Sachem/Strongfield and parents were phenotyped for seedling reaction to leaf ...

  8. Transfer of stripe rust resistance from Aegilops variabilis to bread ...

    African Journals Online (AJOL)

    In terms of area, the bread wheat producing regions of China comprise the largest area in the world that is constantly threatened by stripe rust epidemics. Consequently, it is important to exploit new adultplant resistance genes in breeding. This study reports the transfer of stripe rust resistance from Aegilops variabilis to ...

  9. Mapping of stripe rust resistance gene in an Aegilops caudata ...

    Indian Academy of Sciences (India)

    ... rust resistance depicted a single major gene conditioning adult plant resistance (APR) with stripe rust reaction varying from TR-20MS in resistant RILs signifying the presence of some minor genes as well. Genetic association with leaf rust resistance revealed that two genes are located at a recombination distance of 13%.

  10. Mapping of stripe rust resistance gene in an Aegilops caudata ...

    Indian Academy of Sciences (India)

    Artificial rust epidemic was created by spraying the infector rows and experimental material with the mixture of uredinospores of Pst isolates 78S84 and 46S119. Stripe rust assessment was according to the modified Cobb's scale. (Peterson et al. 1948). The RIL population was screened at the seedling stage against leaf rust ...

  11. Identification and mapping of leaf, stem and stripe rust resistance quantitative trait loci and their interactions in durum wheat.

    Science.gov (United States)

    Singh, A; Pandey, M P; Singh, A K; Knox, R E; Ammar, K; Clarke, J M; Clarke, F R; Singh, R P; Pozniak, C J; Depauw, R M; McCallum, B D; Cuthbert, R D; Randhawa, H S; Fetch, T G

    2013-02-01

    Leaf rust (Puccinia triticina Eriks.), stripe rust (Puccinia striiformis f. tritici Eriks.) and stem rust (Puccinia graminis f. sp. tritici) cause major production losses in durum wheat (Triticum turgidum L. var. durum). The objective of this research was to identify and map leaf, stripe and stem rust resistance loci from the French cultivar Sachem and Canadian cultivar Strongfield. A doubled haploid population from Sachem/Strongfield and parents were phenotyped for seedling reaction to leaf rust races BBG/BN and BBG/BP and adult plant response was determined in three field rust nurseries near El Batan, Obregon and Toluca, Mexico. Stripe rust response was recorded in 2009 and 2011 nurseries near Toluca and near Njoro, Kenya in 2010. Response to stem rust was recorded in field nurseries near Njoro, Kenya, in 2010 and 2011. Sachem was resistant to leaf, stripe and stem rust. A major leaf rust quantitative trait locus (QTL) was identified on chromosome 7B at Xgwm146 in Sachem. In the same region on 7B, a stripe rust QTL was identified in Strongfield. Leaf and stripe rust QTL around DArT marker wPt3451 were identified on chromosome 1B. On chromosome 2B, a significant leaf rust QTL was detected conferred by Strongfield, and at the same QTL, a Yr gene derived from Sachem conferred resistance. Significant stem rust resistance QTL were detected on chromosome 4B. Consistent interactions among loci for resistance to each rust type across nurseries were detected, especially for leaf rust QTL on 7B. Sachem and Strongfield offer useful sources of rust resistance genes for durum rust breeding.

  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

    Stripe or yellow rust of wheat, caused by Puccinia striiformis f. sp. tritici, is an important disease in many wheat-growing regions of the world. A number of major genes providing resistance to stripe rust have been used in breeding, including one gene that is present in the differential tester...... Carstens V. The objective of this study was to locate and map a stripe rust resistance gene transferred from Carstens V to Avocet S and to use molecular tools to locate a number of genes segregating in the cross Savannah/Senat. One of the genes present in Senat was predicted to be a gene that is present...... 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...

  13. Mapping of stripe rust resistance gene in an Aegilops caudata ...

    Indian Academy of Sciences (India)

    Genetic mapping indicated the introgression of stripe rust resistance gene on wheat chromosome. 5DS in the region carrying leaf rust resistance gene LrAc, but as an independent introgression. Simple sequence repeat (SSR) and sequence-tagged site (STS) markers designed from the survey sequence data of 5DS ...

  14. Genetics of leaf and stripe rust resistance in a bread wheat cultivar ...

    Indian Academy of Sciences (India)

    MYT), Mexico, has shown resistance to leaf rust and stripe rust in the Indian ... rust resistance against. -isogenic line genes present Leaf rust. Stripe rust. Origin. Source. Parentage. Tonichi. –. TR. 10.0. Mexico. RAMC CAR422/Anahuac75. CSP44. Lr48 .... separately have been reported earlier by several authors. Table 2.

  15. Identification of QTL conferring resistance to stripe rust (Puccinia striiformis f. sp. hordei) and leaf rust (Puccinia hordei) in barley using nested association mapping (NAM).

    Science.gov (United States)

    Vatter, Thomas; Maurer, Andreas; Perovic, Dragan; Kopahnke, Doris; Pillen, Klaus; Ordon, Frank

    2018-01-01

    The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM) was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars.

  16. Identification of QTL conferring resistance to stripe rust (Puccinia striiformis f. sp. hordei) and leaf rust (Puccinia hordei) in barley using nested association mapping (NAM)

    Science.gov (United States)

    Vatter, Thomas; Maurer, Andreas; Perovic, Dragan; Kopahnke, Doris; Pillen, Klaus

    2018-01-01

    The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM) was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars. PMID:29370232

  17. Identification of QTL conferring resistance to stripe rust (Puccinia striiformis f. sp. hordei and leaf rust (Puccinia hordei in barley using nested association mapping (NAM.

    Directory of Open Access Journals (Sweden)

    Thomas Vatter

    Full Text Available The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars.

  18. Genetic characterisation of novel resistance alleles to stem rust and stripe rust in wheat-alien introgression lines

    OpenAIRE

    Rahmatov, Mahbubjon

    2016-01-01

    Bread wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) is one of the most important food crops world-wide, but is attacked by many diseases and pests that cause significant yield losses. Globally, stem rust (Sr) (Puccinia graminis f. sp. tritici Erikss & E. Henning), stripe rust (Yr) (Puccinia striiformis Westend. f. sp. tritici Eriks) and leaf rust (Lr) (Puccinia triticina Eriks) are a great threat to wheat production. The majority of the Sr, Yr and Lr resistance genes are already defeated...

  19. Partial resistance to stripe rust and its effect on sustainability of wheat yield

    International Nuclear Information System (INIS)

    Qamar, M.; Din, R.U.; Gardazi, D.A.

    2014-01-01

    Stripe rust (Puccinia striiformis Westend. f. sp. tritici) poses a serious threat to wheat production in cooler areas of Pakistan. The 70% area of wheat in Pakistan is prone to stripe rust disease. It can cause 10-17% yield losses if susceptible cultivars are planted under favorable conditions. Level of partial plant resistance in bread wheat and its impact on sustainable wheat production was studied at the National Agricultural Research Centre, Islamabad under natural conditions in the field. Eleven Pakistani commercial wheat cultivars/advance lines including check (Inqalab 91) were assessed for the level of partial resistance against stripe rust using Area Under the Disease Progress Curve (AUDPC), disease severity (DS) and epidemic growth rate in comparison with wheat cultivar, Inqalab 91. During 2007 cropping season, natural epidemic was developed and relative AUDPC was recorded from 0 to 100% whereas the 2008 cropping season was dry and no stripe rust appeared. Two advanced lines (NR 268 and NR 285) showed the infection type (IT) less than 7 (incompatible reaction) to the mixture of prevailing stripe rust inoculums. Very low level of DS and AUDPC were recorded in the remaining cultivars/lines indicating a high level of partial resistance to stripe rust compared to the susceptible check cultivar, Inqalab 91. Among eight cultivars/lines that showed compatible type of reaction (IT greater then equal to 7), one was resistant (relative AUDPC = 20% of Inqalab 91) and six showed very high resistance levels (relative AUDPC greater then equal to 5%). Maximum level of resistance (relative AUDPC = 0.1%) was observed in advanced line, NR 271. The wheat cultivars/lines that showed a slow disease development (low DS and AUDPC), could be considered as -1 partially resistant for stripe rust infection. The yield (2178 kg ha) of susceptible check cultivar Inqalab-91 during 2007 was reduced to 45% as -1 compared to its yield (3945 kg ha) in epidemic free year (2008). Thus the use

  20. Strategies for Wheat Stripe Rust Pathogenicity Identified by Transcriptome Sequencing.

    Directory of Open Access Journals (Sweden)

    Diana P Garnica

    Full Text Available Stripe rust caused by the fungus Puccinia striiformis f.sp. tritici (Pst is a major constraint to wheat production worldwide. The molecular events that underlie Pst pathogenicity are largely unknown. Like all rusts, Pst creates a specialized cellular structure within host cells called the haustorium to obtain nutrients from wheat, and to secrete pathogenicity factors called effector proteins. We purified Pst haustoria and used next-generation sequencing platforms to assemble the haustorial transcriptome as well as the transcriptome of germinated spores. 12,282 transcripts were assembled from 454-pyrosequencing data and used as reference for digital gene expression analysis to compare the germinated uredinospores and haustoria transcriptomes based on Illumina RNAseq data. More than 400 genes encoding secreted proteins which constitute candidate effectors were identified from the haustorial transcriptome, with two thirds of these up-regulated in this tissue compared to germinated spores. RT-PCR analysis confirmed the expression patterns of 94 effector candidates. The analysis also revealed that spores rely mainly on stored energy reserves for growth and development, while haustoria take up host nutrients for massive energy production for biosynthetic pathways and the ultimate production of spores. Together, these studies substantially increase our knowledge of potential Pst effectors and provide new insights into the pathogenic strategies of this important organism.

  1. 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.

  2. Remapping of the stripe rust resistance gene Yr10 in common wheat.

    Science.gov (United States)

    Yuan, Cuiling; Wu, Jingzheng; Yan, Baiqiang; Hao, Qunqun; Zhang, Chaozhong; Lyu, Bo; Ni, Fei; Caplan, Allan; Wu, Jiajie; Fu, Daolin

    2018-02-23

    Yr10 is an important gene to control wheat stripe rust, and the search for Yr10 needs to be continued. Wheat stripe rust or yellow rust is a devastating fungal disease caused by Puccinia striiformis f. sp. tritici (Pst). Host disease resistance offers a primary source for controlling wheat stripe rust. The stripe rust resistance gene Yr10 confers the race-specific resistance to most tested Pst races in China including CYR29. Early studies proposed that Yr10 was a nucleotide-binding site, leucine-rich repeat gene archived as GenBank accession AF149112 (hereafter designated the Yr10 candidate gene or Yr10 CG ). In this study, we revealed that 15 Chinese wheat cultivars positive for Yr10 CG are susceptible to CYR29. We then expressed the Yr10 CG cDNA in the common wheat 'Bobwhite'. The Yr10 CG -cDNA positive transgenic plants were also susceptible to CYR29. Thus, it is highly unlikely that Yr10 CG corresponds to the Yr10 resistance gene. Using the Yr10 donor 'Moro' and the Pst-susceptible wheat 'Huixianhong', we generated two F 3 populations that displayed a single Mendelian segregation on the Yr10 gene, and used them to remap the Yr10 gene. Six markers were placed in the Yr10 region, with the Yr10 CG gene now mapping about 1.2-cM proximal to the Yr10 locus and the Xsdauw79 marker is completely linked to the Yr10 locus. Apparently, the Yr10 gene has not yet been identified. Fine mapping and positional cloning of Yr10 is important for gene pyramiding for stripe rust resistance in wheat.

  3. 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.

  4. Genetics of adult plant stripe rust resistance in CSP44, a selection ...

    Indian Academy of Sciences (India)

    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 ...

  5. Genetics of adult plant stripe rust resistance in CSP44, a selection ...

    Indian Academy of Sciences (India)

    Unknown

    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 ...

  6. Stripe rust and leaf rust resistance QTL mapping, epistatic interactions, and co-localization with stem rust resistance loci in spring wheat evaluated over three continents.

    Science.gov (United States)

    Singh, A; Knox, R E; DePauw, R M; Singh, A K; Cuthbert, R D; Campbell, H L; Shorter, S; Bhavani, S

    2014-11-01

    In wheat, advantageous gene-rich or pleiotropic regions for stripe, leaf, and stem rust and epistatic interactions between rust resistance loci should be accounted for in plant breeding strategies. Leaf rust (Puccinia triticina Eriks.) and stripe rust (Puccinia striiformis f. tritici Eriks) contribute to major production losses in many regions worldwide. The objectives of this research were to identify and study epistatic interactions of quantitative trait loci (QTL) for stripe and leaf rust resistance in a doubled haploid (DH) population derived from the cross of Canadian wheat cultivars, AC Cadillac and Carberry. The relationship of leaf and stripe rust resistance QTL that co-located with stem rust resistance QTL previously mapped in this population was also investigated. The Carberry/AC Cadillac population was genotyped with DArT(®) and simple sequence repeat markers. The parents and population were phenotyped for stripe rust severity and infection response in field rust nurseries in Kenya (Njoro), Canada (Swift Current), and New Zealand (Lincoln); and for leaf rust severity and infection response in field nurseries in Canada (Swift Current) and New Zealand (Lincoln). AC Cadillac was a source of stripe rust resistance QTL on chromosomes 2A, 2B, 3A, 3B, 5B, and 7B; and Carberry was a source of resistance on chromosomes 2B, 4B, and 7A. AC Cadillac contributed QTL for resistance to leaf rust on chromosome 2A and Carberry contributed QTL on chromosomes 2B and 4B. Stripe rust resistance QTL co-localized with previously reported stem rust resistance QTL on 2B, 3B, and 7B, while leaf rust resistance QTL co-localized with 4B stem rust resistance QTL. Several epistatic interactions were identified both for stripe and leaf rust resistance QTL. We have identified useful combinations of genetic loci with main and epistatic effects. Multiple disease resistance regions identified on chromosomes 2A, 2B, 3B, 4B, 5B, and 7B are prime candidates for further investigation and

  7. 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

    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...... 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...

  8. Genetic analysis and location of gene for resistance to stripe rust in ...

    Indian Academy of Sciences (India)

    2013-08-06

    Aug 6, 2013 ... to rust race CYR26. The gene YrSD in Strube Dickkopf resistant to stripe rust CYR26 using SSR method was located on chromosome 5B. There are four pairs (Wmc640,. Barc59, Wmc783 and Wms497) polymorphic SSR primers on chromosome 5B which produced polymorphic DNA bands between the ...

  9. 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.

  10. Introgression of Chromosome 3Ns from Psathyrostachys huashanica into Wheat Specifying Resistance to Stripe Rust

    Science.gov (United States)

    Kang, Houyang; Wang, Yi; Fedak, George; Cao, Wenguang; Zhang, Haiqin; Fan, Xing; Sha, Lina; Xu, Lili; Zheng, Youliang; Zhou, Yonghong

    2011-01-01

    Wheat stripe rust is a destructive disease in the cool and humid wheat-growing areas of the world. Finding diverse sources of stripe rust resistance is critical for increasing genetic diversity of resistance for wheat breeding programs. Stripe rust resistance was identified in the alien species Psathyrostachys huashanica, and a wheat- P. huashanica amphiploid line (PHW-SA) with stripe rust resistance was reported previously. In this study, a P. huashanica 3Ns monosomic addition line (PW11) with superior resistance to stripe rust was developed, which was derived from the cross between PHW-SA and wheat J-11. We evaluated the alien introgressions PW11-2, PW11-5 and PW11-8 which were derived from line PW11 for reaction to new Pst race CYR32, and used molecular and cytogenetic tools to characterize these lines. The introgressions were remarkably resistant to CYR32, suggesting that the resistance to stripe rust of the introgressions thus was controlled by gene(s) located on P. huashanica chromosome 3Ns. All derived lines were cytologically stable in term of meiotic chromosome behavior. Two 3Ns chromosomes of P. huashanica were detected in the disomic addition line PW11-2. Chromosomes 1B of substitution line PW11-5 had been replaced by a pair of P. huashanica 3Ns chromosomes. In PW11-8, a small terminal segment from P. huashanica chromosome arm 3NsS was translocated to the terminal region of wheat chromosomes 3BL. Thus, this translocated chromosome is designated T3BL-3NsS. These conclusions were further confirmed by SSR analyses. Two 3Ns-specific markers Xgwm181 and Xgwm161 will be useful to rapidly identify and trace the translocated fragments. These introgressions, which had significant characteristics of resistance to stripe rust, could be utilized as novel germplasms for wheat breeding. PMID:21760909

  11. Mapping of stripe rust resistance QTL in Cappelle-Desprez × PBW343 RIL population effective in northern wheat belt of India.

    Science.gov (United States)

    Pawar, Sushma Kumari; Sharma, Davinder; Duhan, Joginder Singh; Saharan, Mahender Singh; Tiwari, Ratan; Sharma, Indu

    2016-06-01

    Stripe rust caused by Puccinia striiformis f. sp. tritici is most important and devastating disease of wheat worldwide, which affects the grain yields, quality and nutrition. To elucidate, the genetic basis of resistance, a mapping population of recombinant inbred lines was developed from a cross between resistant Cappelle-Desprez and susceptible cultivar PBW343 using single-seed descent. Variety PBW343 had been one of the most popular cultivars of North Western Plains Zone, for more than a decade, before succumbing to the stripe rust. Cappelle-Desprez, a source of durable adult plant resistance, has maintained its resistance against stripe rust for a long time in Europe. Map construction and QTL analysis were completed with 1012 polymorphic (DArT and SSR) markers. Screenings for stripe rust disease were carried out in field condition for two consecutive crop seasons (2012-2013 and 2013-2014). Susceptible parent (PBW343) achieved a significant level of disease i.e., 100 % in both the years. In present investigations, resistance in Cappelle-Desprez was found stable and response to the rust ranged from 0 to 1.5 % over the years. The estimated broad-sense heritability (h 2 ) of stripe rust rAUDPC in the mapping population was 0.82. The relative area under the disease progress curve data showed continuous distributions, indicating that trait was controlled multigenically. Genomic region identified on chromosome 2D, was located within the short arm, with flanking markers (Xgwm484-Xcfd73), explained phenotypic variation (PVE) ranged from 13.9 to 31.8 %. The genomic region identified on chromosome 5B was found with the effect of maximum contribution with flanking DArT markers (1376633|F|0-1207571|F|0), PVE ranged from 24 to 27.0 %. This can, therefore, be utilized for marker assisted selection in developing much needed stripe rust resistant lines for the northern wheat belt of India.

  12. Stem and stripe rust resistance in wheat induced by gamma rays and thermal neutrons

    International Nuclear Information System (INIS)

    Skorda, E.A.

    1977-01-01

    Attempts were made to produce rust-resistant mutants in wheat cultivars. Seeds of G-38290 and G-58383 (T. aestivum), Methoni and Ilectra (T. durum) varieties were irradiated with different doses of γ-rays (3.5, 5, 8, 11, 15 and 21 krad) and thermal neutrons (1.7, 4, 5.5, 7.5, 10.5 and 12.5x10 12 ) and the M 1 plants were grown under isolation in the field. The objective was mainly to induce stripe, leaf and stem rust resistance in G-38290, Methoni and Ilectra varieties and leaf rust resistance in G-58383. Mutations for rust resistance were detected by using the ''chimera method'' under natural and artificial field epiphytotic conditions in M 2 and successive generations. The mutants detected were tested for resistance to a broad spectrum of available races. Mutants resistant or moderately resistant to stripe and stem rusts but not to leaf rust, were selected from G-38290. From the other three varieties tested no rust-resistant mutants were detected. The frequency of resistant mutants obtained increased with increased γ-ray dose-rate, but not with increased thermal neutron doses. Some mutants proved to be resistant or moderately resistant to both rusts and others to one of them. Twenty of these mutants were evaluated for yield from M 5 to M 8 . Some of them have reached the final stage of regional yield trials and one, induced by thermal neutrons, was released this year. (author)

  13. 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

  14. Mapping of stripe rust resistance gene in an Aegilops caudate introgression line in wheat and its genetic association with leaf rust resistance.

    Science.gov (United States)

    Toor, Puneet Inder; Kaur, Satinder; Bansal, Mitaly; Yadav, Bharat; Chhuneja, Parveen

    2016-12-01

    A pair of stripe rust and leaf rust resistance genes was introgressed from Aegilops caudata, a nonprogenitor diploid species with the CC genome, to cultivated wheat. Inheritance and genetic mapping of stripe rust resistance gene in backcrossrecombinant inbred line (BC-RIL) population derived from the cross of a wheat-Ae. caudata introgression line (IL) T291- 2(pau16060) with wheat cv. PBW343 is reported here. Segregation of BC-RILs for stripe rust resistance depicted a single major gene conditioning adult plant resistance (APR) with stripe rust reaction varying from TR-20MS in resistant RILs signifying the presence of some minor genes as well. Genetic association with leaf rust resistance revealed that two genes are located at a recombination distance of 13%. IL T291-2 had earlier been reported to carry introgressions on wheat chromosomes 2D, 3D, 4D, 5D, 6D and 7D. Genetic mapping indicated the introgression of stripe rust resistance gene on wheat chromosome 5DS in the region carrying leaf rust resistance gene LrAc, but as an independent introgression. Simple sequence repeat (SSR) and sequence-tagged site (STS) markers designed from the survey sequence data of 5DS enriched the target region harbouring stripe and leaf rust resistance genes. Stripe rust resistance locus, temporarily designated as YrAc, mapped at the distal most end of 5DS linked with a group of four colocated SSRs and two resistance gene analogue (RGA)-STS markers at a distance of 5.3 cM. LrAc mapped at a distance of 9.0 cM from the YrAc and at 2.8 cM from RGA-STS marker Ta5DS_2737450, YrAc and LrAc appear to be the candidate genes for marker-assisted enrichment of the wheat gene pool for rust resistance.

  15. Small RNAs from the wheat stripe rust fungus (Puccinia striiformis f.sp. tritici).

    Science.gov (United States)

    Mueth, Nicholas A; Ramachandran, Sowmya R; Hulbert, Scot H

    2015-09-21

    Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is a costly global disease that burdens farmers with yield loss and high fungicide expenses. This sophisticated biotrophic parasite infiltrates wheat leaves and develops infection structures inside host cells, appropriating nutrients while suppressing the plant defense response. Development in most eukaryotes is regulated by small RNA molecules, and the success of host-induced gene silencing technology in Puccinia spp. implies the existence of a functional RNAi system. However, some fungi lack this capability, and small RNAs have not yet been reported in rust fungi. The objective of this study was to determine whether P. striiformis carries an endogenous small RNA repertoire. We extracted small RNA from rust-infected wheat flag leaves and performed high-throughput sequencing. Two wheat cultivars were analyzed: one is susceptible; the other displays partial high-temperature adult plant resistance. Fungal-specific reads were identified by mapping to the P. striiformis draft genome and removing reads present in uninfected control libraries. Sequencing and bioinformatics results were verified by RT-PCR. Like other RNAi-equipped fungi, P. striiformis produces large numbers of 20-22 nt sequences with a preference for uracil at the 5' position. Precise post-transcriptional processing and high accumulation of specific sRNA sequences were observed. Some predicted sRNA precursors possess a microRNA-like stem-loop secondary structure; others originate from much longer inverted repeats containing gene sequences. Finally, sRNA-target prediction algorithms were used to obtain a list of putative gene targets in both organisms. Predicted fungal target genes were enriched for kinases and small secreted proteins, while the list of wheat targets included homologs of known plant resistance genes. This work provides an inventory of small RNAs endogenous to an important plant pathogen, enabling further exploration of gene

  16. Wheat stripe rust resistance protein WKS1 reduces the ability of the thylakoid-associated ascorbate peroxidase to detoxify reactive oxygen species

    Science.gov (United States)

    Stripe rust is a devastating fungal disease of wheat caused by Puccinia striiformis f. sp. tritici(Pst). The 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 plants transformed w...

  17. Genetics of adult plant stripe rust resistance in CSP44, a selection ...

    Indian Academy of Sciences (India)

    Unknown

    areas of temperate zones (Johnson 1988). Yield losses can be considerable, ranging from about 40 per cent to com- plete destruction of the crop depending upon the growth stage at which the disease attacks. Using diverse genes for resistance against stripe rust disease is the most eco- nomical and environmentally safe ...

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

    Indian Academy of Sciences (India)

    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 ...

  19. Mapping of quantitative adult plant field resistance to leaf rust and stripe rust in two European winter wheat populations reveals co-location of three QTL conferring resistance to both rust pathogens.

    Science.gov (United States)

    Buerstmayr, Maria; Matiasch, Lydia; Mascher, Fabio; Vida, Gyula; Ittu, Marianna; Robert, Olivier; Holdgate, Sarah; Flath, Kerstin; Neumayer, Anton; Buerstmayr, Hermann

    2014-09-01

    We detected several, most likely novel QTL for adult plant resistance to rusts. Notably three QTL improved resistance to leaf rust and stripe rust simultaneously indicating broad spectrum resistance QTL. The rusts of wheat (Puccinia spp.) are destructive fungal wheat diseases. The deployment of resistant cultivars plays a central role in integrated rust disease management. Durability of resistance would be preferred, but is difficult to analyse. The Austrian winter wheat cultivar Capo was released in the 1989 and grown on a large acreage during more than two decades and maintained a good level of quantitative leaf rust and stripe rust resistance. Two bi-parental mapping populations: Capo × Arina and Capo × Furore were tested in multiple environments for severity of leaf rust and stripe rust at the adult plant stage in replicated field experiments. Quantitative trait loci associated with leaf rust and stripe rust severity were mapped using DArT and SSR markers. Five QTL were detected in multiple environments associated with resistance to leaf rust designated as QLr.ifa-2AL, QLr.ifa-2BL, QLr.ifa-2BS, QLr.ifa-3BS, and QLr.ifa-5BL, and five for resistance to stripe rust QYr.ifa-2AL, QYr.ifa-2BL, QYr.ifa-3AS, QYr.ifa-3BS, and QYr.ifa-5A. For all QTL apart from two (QYr.ifa-3AS, QLr.ifa-5BL) Capo contributed the resistance improving allele. The leaf rust and stripe rust resistance QTL on 2AL, 2BL and 3BS mapped to the same chromosome positions, indicating either closely linked genes or pleiotropic gene action. These three multiple disease resistance QTL (QLr.ifa-2AL/QYr.ifa-2AL, QLr.ifa.2BL/QYr.ifa-2BL, QLr.ifa-3BS/QYr.ifa.3BS) potentially contribute novel resistance sources for stripe rust and leaf rust. The long-lasting resistance of Capo apparently rests upon a combination of several genes. The described germplasm, QTL and markers are applicable for simultaneous resistance improvement against leaf rust and stripe rust.

  20. Quantitative trait loci for resistance to stripe rust of wheat revealed using global field nurseries and opportunities for stacking resistance genes.

    Science.gov (United States)

    Bokore, Firdissa E; Cuthbert, Richard D; Knox, Ron E; Randhawa, Harpinder S; Hiebert, Colin W; DePauw, Ron M; Singh, Asheesh K; Singh, Arti; Sharpe, Andrew G; N'Diaye, Amidou; Pozniak, Curtis J; McCartney, Curt; Ruan, Yuefeng; Berraies, Samia; Meyer, Brad; Munro, Catherine; Hay, Andy; Ammar, Karim; Huerta-Espino, Julio; Bhavani, Sridhar

    2017-12-01

    Quantitative trait loci controlling stripe rust resistance were identified in adapted Canadian spring wheat cultivars providing opportunity for breeders to stack loci using marker-assisted breeding. Stripe rust or yellow rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss., is a devastating disease of common wheat (Triticum aestivum L.) in many regions of the world. The objectives of this research were to identify and map quantitative trait loci (QTL) associated with stripe rust resistance in adapted Canadian spring wheat cultivars that are effective globally, and investigate opportunities for stacking resistance. Doubled haploid (DH) populations from the crosses Vesper/Lillian, Vesper/Stettler, Carberry/Vesper, Stettler/Red Fife and Carberry/AC Cadillac were phenotyped for stripe rust severity and infection response in field nurseries in Canada (Lethbridge and Swift Current), New Zealand (Lincoln), Mexico (Toluca) and Kenya (Njoro), and genotyped with SNP markers. Six QTL for stripe rust resistance in the population of Vesper/Lillian, five in Vesper/Stettler, seven in Stettler/Red Fife, four in Carberry/Vesper and nine in Carberry/AC Cadillac were identified. Lillian contributed stripe rust resistance QTL on chromosomes 4B, 5A, 6B and 7D, AC Cadillac on 2A, 2B, 3B and 5B, Carberry on 1A, 1B, 4A, 4B, 7A and 7D, Stettler on 1A, 2A, 3D, 4A, 5B and 6A, Red Fife on 2D, 3B and 4B, and Vesper on 1B, 2B and 7A. QTL on 1A, 1B, 2A, 2B, 3B, 4A, 4B, 5B, 7A and 7D were observed in multiple parents. The populations are compelling sources of recombination of many stripe rust resistance QTL for stacking disease resistance. Gene pyramiding should be possible with little chance of linkage drag of detrimental genes as the source parents were mostly adapted cultivars widely grown in Canada.

  1. Characterization of molecular diversity and genome-wide mapping of loci associated with resistance to stripe rust and stem rust in Ethiopian bread wheat accessions.

    Science.gov (United States)

    Muleta, Kebede T; Rouse, Matthew N; Rynearson, Sheri; Chen, Xianming; Buta, Bedada G; Pumphrey, Michael O

    2017-08-04

    The narrow genetic basis of resistance in modern wheat cultivars and the strong selection response of pathogen populations have been responsible for periodic and devastating epidemics of the wheat rust diseases. Characterizing new sources of resistance and incorporating multiple genes into elite cultivars is the most widely accepted current mechanism to achieve durable varietal performance against changes in pathogen virulence. Here, we report a high-density molecular characterization and genome-wide association study (GWAS) of stripe rust and stem rust resistance in 190 Ethiopian bread wheat lines based on phenotypic data from multi-environment field trials and seedling resistance screening experiments. A total of 24,281 single nucleotide polymorphism (SNP) markers filtered from the wheat 90 K iSelect genotyping assay was used to survey Ethiopian germplasm for population structure, genetic diversity and marker-trait associations. Upon screening for field resistance to stripe rust in the Pacific Northwest of the United States and Ethiopia over multiple growing seasons, and against multiple races of stripe rust and stem rust at seedling stage, eight accessions displayed resistance to all tested races of stem rust and field resistance to stripe rust in all environments. Our GWAS results show 15 loci were significantly associated with seedling and adult plant resistance to stripe rust at false discovery rate (FDR)-adjusted probability (P) rust in the Ethiopian wheat accessions. Many of the identified resistance loci were mapped close to previously identified rust resistance genes; however, three loci on the short arms of chromosomes 5A and 7B for stripe rust resistance and two on chromosomes 3B and 7B for stem rust resistance may be novel. Our results demonstrate that considerable genetic variation resides within the landrace accessions that can be utilized to broaden the genetic base of rust resistance in wheat breeding germplasm. The molecular markers identified in

  2. Loci associated with resistance to stripe rust (Puccinia striiformis f. sp. tritici) in a core collection of spring wheat (Triticum aestivum)

    Science.gov (United States)

    Bulli, Peter; Rynearson, Sheri; Chen, Xianming; Pumphrey, Michael

    2017-01-01

    Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst) remains one of the most significant diseases of wheat worldwide. We investigated stripe rust resistance by genome-wide association analysis (GWAS) in 959 spring wheat accessions from the United States Department of Agriculture-Agricultural Research Service National Small Grains Collection, representing major global production environments. The panel was characterized for field resistance in multi-environment field trials and seedling resistance under greenhouse conditions. A genome-wide set of 5,619 informative SNP markers were used to examine the population structure, linkage disequilibrium and marker-trait associations in the germplasm panel. Based on model-based analysis of population structure and hierarchical Ward clustering algorithm, the accessions were clustered into two major subgroups. These subgroups were largely separated according to geographic origin and improvement status of the accessions. A significant correlation was observed between the population sub-clusters and response to stripe rust infection. We identified 11 and 7 genomic regions with significant associations with stripe rust resistance at adult plant and seedling stages, respectively, based on a false discovery rate multiple correction method. The regions harboring all, except three, of the QTL identified from the field and greenhouse studies overlap with positions of previously reported QTL. Further work should aim at validating the identified QTL using proper germplasm and populations to enhance their utility in marker assisted breeding. PMID:28591221

  3. [Prediction model of meteorological grade of wheat stripe rust in winter-reproductive area, Sichuan Basin, China].

    Science.gov (United States)

    Guo, Xiang; Wang, Ming Tian; Zhang, Guo Zhi

    2017-12-01

    The winter reproductive areas of Puccinia striiformis var. striiformis in Sichuan Basin are often the places mostly affected by wheat stripe rust. With data on the meteorological condition and stripe rust situation at typical stations in the winter reproductive area in Sichuan Basin from 1999 to 2016, this paper classified the meteorological conditions inducing wheat stripe rust into 5 grades, based on the incidence area ratio of the disease. The meteorological factors which were biologically related to wheat stripe rust were determined through multiple analytical methods, and a meteorological grade model for forecasting wheat stripe rust was created. The result showed that wheat stripe rust in Sichuan Basin was significantly correlated with many meteorological factors, such as the ave-rage (maximum and minimum) temperature, precipitation and its anomaly percentage, relative humidity and its anomaly percentage, average wind speed and sunshine duration. Among these, the average temperature and the anomaly percentage of relative humidity were the determining factors. According to a historical retrospective test, the accuracy of the forecast based on the model was 64% for samples in the county-level test, and 89% for samples in the municipal-level test. In a meteorological grade forecast of wheat stripe rust in the winter reproductive areas in Sichuan Basin in 2017, the prediction was accurate for 62.8% of the samples, with 27.9% error by one grade and only 9.3% error by two or more grades. As a result, the model could deliver satisfactory forecast results, and predicate future wheat stripe rust from a meteorological point of view.

  4. Characterization and Mapping of Leaf Rust and Stripe Rust Resistance Loci in Hexaploid Wheat Lines UC1110 and PI610750 under Mexican Environments

    Directory of Open Access Journals (Sweden)

    Caixia Lan

    2017-08-01

    Full Text Available Growing resistant wheat varieties is a key method of minimizing the extent of yield losses caused by the globally important wheat leaf rust (LR and stripe rust (YR diseases. In this study, a population of 186 F8 recombinant inbred lines (RILs derived from a cross between a synthetic wheat derivative (PI610750 and an adapted common wheat line (cv. “UC1110” were phenotyped for LR and YR response at both seedling and adult plant stages over multiple seasons. Using a genetic linkage map consisting of single sequence repeats and diversity arrays technology markers, in combination with inclusive composite interval mapping analysis, we detected a new LR adult plant resistance (APR locus, QLr.cim-2DS, contributed by UC1110. One co-located resistance locus to both rusts, QLr.cim-3DC/QYr.cim-3DC, and the known seedling resistance gene Lr26 were also mapped. QLr.cim-2DS and QLr.cim-3DC showed a marginally significant interaction for LR resistance in the adult plant stage. In addition, two previously reported YR APR loci, QYr.ucw-3BS and Yr48, were found to exhibit stable performances in rust environments in both Mexico and the United States and showed a highly significant interaction in the field. Yr48 was also observed to confer intermediate seedling resistance against Mexican YR races, thus suggesting it should be re-classified as an all-stage resistance gene. We also identified 5 and 2 RILs that possessed all detected YR and LR resistance loci, respectively. With the closely linked molecular markers reported here, these RILs could be used as donors for multiple resistance loci to both rusts in wheat breeding programs.

  5. Characterization and Mapping of Leaf Rust and Stripe Rust Resistance Loci in Hexaploid Wheat Lines UC1110 and PI610750 under Mexican Environments.

    Science.gov (United States)

    Lan, Caixia; Hale, Iago L; Herrera-Foessel, Sybil A; Basnet, Bhoja R; Randhawa, Mandeep S; Huerta-Espino, Julio; Dubcovsky, Jorge; Singh, Ravi P

    2017-01-01

    Growing resistant wheat varieties is a key method of minimizing the extent of yield losses caused by the globally important wheat leaf rust (LR) and stripe rust (YR) diseases. In this study, a population of 186 F 8 recombinant inbred lines (RILs) derived from a cross between a synthetic wheat derivative (PI610750) and an adapted common wheat line (cv. "UC1110") were phenotyped for LR and YR response at both seedling and adult plant stages over multiple seasons. Using a genetic linkage map consisting of single sequence repeats and diversity arrays technology markers, in combination with inclusive composite interval mapping analysis, we detected a new LR adult plant resistance (APR) locus, QLr.cim-2DS , contributed by UC1110. One co-located resistance locus to both rusts, QLr.cim-3DC/QYr.cim-3DC , and the known seedling resistance gene Lr26 were also mapped. QLr.cim-2DS and QLr.cim-3DC showed a marginally significant interaction for LR resistance in the adult plant stage. In addition, two previously reported YR APR loci, QYr.ucw-3BS and Yr48 , were found to exhibit stable performances in rust environments in both Mexico and the United States and showed a highly significant interaction in the field. Yr48 was also observed to confer intermediate seedling resistance against Mexican YR races, thus suggesting it should be re-classified as an all-stage resistance gene. We also identified 5 and 2 RILs that possessed all detected YR and LR resistance loci, respectively. With the closely linked molecular markers reported here, these RILs could be used as donors for multiple resistance loci to both rusts in wheat breeding programs.

  6. Effective genes for resistance to stripe rust and virulence of Puccinia ...

    African Journals Online (AJOL)

    The results revealed that stripe rust resistance genes Yr3, Yr5, Yr10, Yr15, Yr26, YrSP and YrCV were resistant, while Yr18 showed moderate susceptibility at all locations. Genes YrA-, Yr2, Yr6, Yr7, Yr8, Yr9, Yr17, Yr27 and gene combinations Opata (Yr27+Yr18) and Super Kauz (Yr9, Yr27, Yr18) were found susceptible.

  7. Cytogenetics and stripe rust resistance of wheat-Thinopyrum elongatum hybrid derivatives.

    Science.gov (United States)

    Li, Daiyan; Long, Dan; Li, Tinghui; Wu, Yanli; Wang, Yi; Zeng, Jian; Xu, Lili; Fan, Xing; Sha, Lina; Zhang, Haiqin; Zhou, Yonghong; Kang, Houyang

    2018-01-01

    Amphidiploids generated by distant hybridization are commonly used as genetic bridge to transfer desirable genes from wild wheat species into cultivated wheat. This method is typically used to enhance the resistance of wheat to biotic or abiotic stresses, and to increase crop yield and quality. Tetraploid Thinopyrum elongatum exhibits strong adaptability, resistance to stripe rust and Fusarium head blight, and tolerance to salt, drought, and cold. In the present study, we produced hybrid derivatives by crossing and backcrossing the Triticum durum-Th. elongatum partial amphidiploid ( Trititrigia 8801, 2 n  = 6 ×  = 42, AABBEE) with wheat cultivars common to the Sichuan Basin. By means of cytogenetic and disease resistance analyses, we identified progeny harboring alien chromosomes and measured their resistance to stripe rust. Hybrid progenies possessed chromosome numbers ranging from 40 to 47 (mean = 42.72), with 40.0% possessing 42 chromosomes. Genomic in situ hybridization revealed that the number of alien chromosomes ranged from 1 to 11. Out of the 50 of analyzed lines, five represented chromosome addition (2 n  = 44 = 42 W + 2E) and other five were chromosome substitution lines (2 n  = 42 = 40 W + 2E). Importantly, a single chromosome derived from wheat- Th. elongatum intergenomic Robertsonian translocations chromosome was occurred in 12 lines. Compared with the wheat parental cultivars ('CN16' and 'SM482'), the majority (70%) of the derivative lines were highly resistant to strains of stripe rust pathogen known to be prevalent in China. The findings suggest that these hybrid-derivative lines with stripe rust resistance could potentially be used as germplasm sources for further wheat improvement.

  8. Mapping of stripe rust resistance gene in an Aegilops caudata ...

    Indian Academy of Sciences (India)

    PUNEET INDER TOOR

    end of 5DS linked with a group of four colocated SSRs and two resistance gene analogue (RGA)-STS markers at a distance of 5.3 cM. ... and LrAc appear to be the candidate genes for marker-assisted enrichment of the wheat gene pool for rust resistance. [Toor P. I., Kaur S., Bansal ..... stocks with reduced alien chromatin.

  9. Identification and Severity Determination of Wheat Stripe Rust and Wheat Leaf Rust Based on Hyperspectral Data Acquired Using a Black-Paper-Based Measuring Method

    Science.gov (United States)

    Ruan, Liu; Wang, Rui; Liu, Qi; Ma, Zhanhong; Li, Xiaolong; Cheng, Pei; Wang, Haiguang

    2016-01-01

    It is important to implement detection and assessment of plant diseases based on remotely sensed data for disease monitoring and control. Hyperspectral data of healthy leaves, leaves in incubation period and leaves in diseased period of wheat stripe rust and wheat leaf rust were collected under in-field conditions using a black-paper-based measuring method developed in this study. After data preprocessing, the models to identify the diseases were built using distinguished partial least squares (DPLS) and support vector machine (SVM), and the disease severity inversion models of stripe rust and the disease severity inversion models of leaf rust were built using quantitative partial least squares (QPLS) and support vector regression (SVR). All the models were validated by using leave-one-out cross validation and external validation. The diseases could be discriminated using both distinguished partial least squares and support vector machine with the accuracies of more than 99%. For each wheat rust, disease severity levels were accurately retrieved using both the optimal QPLS models and the optimal SVR models with the coefficients of determination (R2) of more than 0.90 and the root mean square errors (RMSE) of less than 0.15. The results demonstrated that identification and severity evaluation of stripe rust and leaf rust at the leaf level could be implemented based on the hyperspectral data acquired using the developed method. A scientific basis was provided for implementing disease monitoring by using aerial and space remote sensing technologies. PMID:27128464

  10. Identification and Severity Determination of Wheat Stripe Rust and Wheat Leaf Rust Based on Hyperspectral Data Acquired Using a Black-Paper-Based Measuring Method.

    Science.gov (United States)

    Wang, Hui; Qin, Feng; Ruan, Liu; Wang, Rui; Liu, Qi; Ma, Zhanhong; Li, Xiaolong; Cheng, Pei; Wang, Haiguang

    2016-01-01

    It is important to implement detection and assessment of plant diseases based on remotely sensed data for disease monitoring and control. Hyperspectral data of healthy leaves, leaves in incubation period and leaves in diseased period of wheat stripe rust and wheat leaf rust were collected under in-field conditions using a black-paper-based measuring method developed in this study. After data preprocessing, the models to identify the diseases were built using distinguished partial least squares (DPLS) and support vector machine (SVM), and the disease severity inversion models of stripe rust and the disease severity inversion models of leaf rust were built using quantitative partial least squares (QPLS) and support vector regression (SVR). All the models were validated by using leave-one-out cross validation and external validation. The diseases could be discriminated using both distinguished partial least squares and support vector machine with the accuracies of more than 99%. For each wheat rust, disease severity levels were accurately retrieved using both the optimal QPLS models and the optimal SVR models with the coefficients of determination (R2) of more than 0.90 and the root mean square errors (RMSE) of less than 0.15. The results demonstrated that identification and severity evaluation of stripe rust and leaf rust at the leaf level could be implemented based on the hyperspectral data acquired using the developed method. A scientific basis was provided for implementing disease monitoring by using aerial and space remote sensing technologies.

  11. Identification and Severity Determination of Wheat Stripe Rust and Wheat Leaf Rust Based on Hyperspectral Data Acquired Using a Black-Paper-Based Measuring Method.

    Directory of Open Access Journals (Sweden)

    Hui Wang

    Full Text Available It is important to implement detection and assessment of plant diseases based on remotely sensed data for disease monitoring and control. Hyperspectral data of healthy leaves, leaves in incubation period and leaves in diseased period of wheat stripe rust and wheat leaf rust were collected under in-field conditions using a black-paper-based measuring method developed in this study. After data preprocessing, the models to identify the diseases were built using distinguished partial least squares (DPLS and support vector machine (SVM, and the disease severity inversion models of stripe rust and the disease severity inversion models of leaf rust were built using quantitative partial least squares (QPLS and support vector regression (SVR. All the models were validated by using leave-one-out cross validation and external validation. The diseases could be discriminated using both distinguished partial least squares and support vector machine with the accuracies of more than 99%. For each wheat rust, disease severity levels were accurately retrieved using both the optimal QPLS models and the optimal SVR models with the coefficients of determination (R2 of more than 0.90 and the root mean square errors (RMSE of less than 0.15. The results demonstrated that identification and severity evaluation of stripe rust and leaf rust at the leaf level could be implemented based on the hyperspectral data acquired using the developed method. A scientific basis was provided for implementing disease monitoring by using aerial and space remote sensing technologies.

  12. 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

  13. The dissection and SSR mapping of a high-temperature adult-plant stripe rust resistance gene in American spring wheat cultivar Alturas

    Science.gov (United States)

    Stripe rust is one of major diseases in wheat production worldwide. The best economic and efficient method is to utilize resistant varieties. Alturas has high-temperature adult-plant resistance. In order to determine stripe rust resistance characteristics, resistance gene combination and molecular m...

  14. Identification and characterization of pleiotropic and co-located resistance loci to leaf rust and stripe rust in bread wheat cultivar Sujata.

    Science.gov (United States)

    Lan, Caixia; Zhang, Yelun; Herrera-Foessel, Sybil A; Basnet, Bhoja R; Huerta-Espino, Julio; Lagudah, Evans S; Singh, Ravi P

    2015-03-01

    Two new co-located resistance loci, QLr.cim - 1AS/QYr.cim - 1AS and QLr.cim - 7BL/YrSuj , in combination with Lr46 / Yr29 and Lr67/Yr46 , and a new leaf rust resistance quantitative trait loci, conferred high resistance to rusts in adult plant stage. The tall Indian bread wheat cultivar Sujata displays high and low infection types to leaf rust and stripe rust, respectively, at the seedling stage in greenhouse tests. It was also highly resistant to both rusts at adult plant stage in field trials in Mexico. The genetic basis of this resistance was investigated in a population of 148 F5 recombinant inbred lines (RILs) derived from the cross Avocet × Sujata. The parents and RIL population were characterized in field trials for resistance to leaf rust during 2011 at El Batán, and 2012 and 2013 at Ciudad Obregón, Mexico, and for stripe rust during 2011 and 2012 at Toluca, Mexico; they were also characterized three times for stripe rust at seedling stage in the greenhouse. The RILs were genotyped with diversity arrays technology and simple sequence repeat markers. The final genetic map was constructed with 673 polymorphic markers. Inclusive composite interval mapping analysis detected two new significant co-located resistance loci, QLr.cim-1AS/QYr.cim-1AS and QLr.cim-7BL/YrSuj, on chromosomes 1AS and 7BL, respectively. The chromosomal position of QLr.cim-7BL overlapped with the seedling stripe rust resistance gene, temporarily designated as YrSuj. Two previously reported pleiotropic adult plant resistance genes, Lr46/Yr29 and Lr67/Yr46, and a new leaf rust resistance quantitative trait loci derived from Avocet were also mapped in the population. The two new co-located resistance loci are expected to contribute to breeding durable rust resistance in wheat. Closely linked molecular markers can be used to transfer all four resistance loci simultaneously to modern wheat varieties.

  15. 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.

  16. Genomic and pedigree-based prediction for leaf, stem, and stripe rust resistance in wheat.

    Science.gov (United States)

    Juliana, Philomin; Singh, Ravi P; Singh, Pawan K; Crossa, Jose; Huerta-Espino, Julio; Lan, Caixia; Bhavani, Sridhar; Rutkoski, Jessica E; Poland, Jesse A; Bergstrom, Gary C; Sorrells, Mark E

    2017-07-01

    Genomic prediction for seedling and adult plant resistance to wheat rusts was compared to prediction using few markers as fixed effects in a least-squares approach and pedigree-based prediction. The unceasing plant-pathogen arms race and ephemeral nature of some rust resistance genes have been challenging for wheat (Triticum aestivum L.) breeding programs and farmers. Hence, it is important to devise strategies for effective evaluation and exploitation of quantitative rust resistance. One promising approach that could accelerate gain from selection for rust resistance is 'genomic selection' which utilizes dense genome-wide markers to estimate the breeding values (BVs) for quantitative traits. Our objective was to compare three genomic prediction models including genomic best linear unbiased prediction (GBLUP), GBLUP A that was GBLUP with selected loci as fixed effects and reproducing kernel Hilbert spaces-markers (RKHS-M) with least-squares (LS) approach, RKHS-pedigree (RKHS-P), and RKHS markers and pedigree (RKHS-MP) to determine the BVs for seedling and/or adult plant resistance (APR) to leaf rust (LR), stem rust (SR), and stripe rust (YR). The 333 lines in the 45th IBWSN and the 313 lines in the 46th IBWSN were genotyped using genotyping-by-sequencing and phenotyped in replicated trials. The mean prediction accuracies ranged from 0.31-0.74 for LR seedling, 0.12-0.56 for LR APR, 0.31-0.65 for SR APR, 0.70-0.78 for YR seedling, and 0.34-0.71 for YR APR. For most datasets, the RKHS-MP model gave the highest accuracies, while LS gave the lowest. GBLUP, GBLUP A, RKHS-M, and RKHS-P models gave similar accuracies. Using genome-wide marker-based models resulted in an average of 42% increase in accuracy over LS. We conclude that GS is a promising approach for improvement of quantitative rust resistance and can be implemented in the breeding pipeline.

  17. Secretome Characterization and Correlation Analysis Reveal Putative Pathogenicity Mechanisms and Identify Candidate Avirulence Genes in the Wheat Stripe Rust Fungus Puccinia striiformis f. sp. tritici.

    Science.gov (United States)

    Xia, Chongjing; Wang, Meinan; Cornejo, Omar E; Jiwan, Derick A; See, Deven R; Chen, Xianming

    2017-01-01

    Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici ( Pst ), is one of the most destructive diseases of wheat worldwide. Planting resistant cultivars is an effective way to control this disease, but race-specific resistance can be overcome quickly due to the rapid evolving Pst population. Studying the pathogenicity mechanisms is critical for understanding how Pst virulence changes and how to develop wheat cultivars with durable resistance to stripe rust. We re-sequenced 7 Pst isolates and included additional 7 previously sequenced isolates to represent balanced virulence/avirulence profiles for several avirulence loci in seretome analyses. We observed an uneven distribution of heterozygosity among the isolates. Secretome comparison of Pst with other rust fungi identified a large portion of species-specific secreted proteins, suggesting that they may have specific roles when interacting with the wheat host. Thirty-two effectors of Pst were identified from its secretome. We identified candidates for Avr genes corresponding to six Yr genes by correlating polymorphisms for effector genes to the virulence/avirulence profiles of the 14 Pst isolates. The putative AvYr76 was present in the avirulent isolates, but absent in the virulent isolates, suggesting that deleting the coding region of the candidate avirulence gene has produced races virulent to resistance gene Yr76 . We conclude that incorporating avirulence/virulence phenotypes into correlation analysis with variations in genomic structure and secretome, particularly presence/absence polymorphisms of effectors, is an efficient way to identify candidate Avr genes in Pst . The candidate effector genes provide a rich resource for further studies to determine the evolutionary history of Pst populations and the co-evolutionary arms race between Pst and wheat. The Avr candidates identified in this study will lead to cloning avirulence genes in Pst , which will enable us to understand molecular mechanisms

  18. Molecular implications from ssr markers for stripe rust (puccinia striiformis F.Sp. tritici) resistance gene in bread wheat line N95175

    International Nuclear Information System (INIS)

    Ali, M.; Ji, W.G.; Hu, Y.G; Zhong, H.; Wang, C.Y.; Baloch, G.M.

    2010-01-01

    Stripe rust caused by Puccinia striiformis f. sp. tritici is one of the most devastating diseases of wheat in China as well as in Pakistan. In the present studies F2 population was established by crossing N95175 resistant to stripe rust race CYR32 with two susceptible lines Huixianhong and Abbondanza to molecularly tag resistance gene existing in wheat line N95175. The segregation of phenotype was accorded with an expected 3:1 ratio in both combinations studied and fit the model of a single dominant gene controlling stripe rust resistance in N95175. Thirty five SSR primer pairs were screened on the parents and bulks and also on individuals since resistance gene to be located in chromosome 1B. The result indicated that most of resistant plants amplified same band as resistant parent while susceptible plants amplified same as susceptible parents studied and considered that markers co-segregated with resistant loci in N95175. This yellow rust resistance gene was considered to be Yr26 originally thought to be also located in chromosome arm 1BS linked to marker loci Xgwm273 and Xgwm11 with genetic distances ranging from 1.075cM to 2.74cM in both combinations studied. However, the closest loci were observed 2.67cM for Xgwm273 and 1.075cM for Xgwm11 in Huixianhong XN95175 and Abbondanza XN95175 crosses respectively. Hence, it has been concluded that the PCR-based micro satellite markers Xgwm273 and Xgwm11 located in chromosome 1B were shown to be very effective for the detection of Yr26 gene in segregating population and can be applied in future wheat breeding strategies. (author)

  19. Genome-wide association mapping for stripe rust (Puccinia striiformis F. sp. tritici) in US Pacific Northwest winter wheat (Triticum aestivum L.).

    Science.gov (United States)

    Naruoka, Y; Garland-Campbell, K A; Carter, A H

    2015-06-01

    Potential novel and known QTL for race-specific all-stage and adult plant resistance to stripe rust were identified by genome-wide association mapping in the US PNW winter wheat accessions. Stripe rust (Puccinia striiformis F. sp. tritici; also known as yellow rust) is a globally devastating disease of wheat (Triticum aestivum L.) and a major threat to wheat production in the US Pacific Northwest (PNW), therefore both adult plant and all-stage resistance have been introduced into the winter wheat breeding programs in the PNW. The goal of this study was to identify quantitative trait loci (QTL) and molecular markers for these resistances through genome-wide association (GWAS) mapping in winter wheat accessions adapted to the PNW. Stripe rust response for adult plants was evaluated in naturally occurring epidemics in a total of nine environments in Washington State, USA. Seedling response was evaluated with three races under artificial inoculation in the greenhouse. The panel was genotyped with the 9K Illumina Wheat single nucleotide polymorphism (SNP) array and additional markers linked to previously reported genes and QTL for stripe rust resistance. The population was grouped into three sub-populations. Markers linked to Yr17 and previously reported QTL for stripe rust resistance were identified on chromosomes 1B, 2A, and 2B. Potentially novel QTL associated with race-specific seedling response were identified on chromosomes 1B and 1D. Potentially novel QTL associated with adult plant response were located on chromosomes 2A, 2B, 3B, 4A, and 4B. Stripe rust was reduced when multiple alleles for resistance were present. The resistant allele frequencies were different among sub-populations in the panel. This information provides breeders with germplasm and closely linked markers for stripe rust resistance to facilitate the transfer of multiple loci for durable stripe rust resistance into wheat breeding lines and cultivars.

  20. Influence of stripe rust infection on the photosynthetic characteristics and antioxidant system of susceptible and resistant wheat cultivars at the adult plant stage.

    Science.gov (United States)

    Chen, Yang-Er; Cui, Jun-Mei; Su, Yan-Qiu; Yuan, Shu; Yuan, Ming; Zhang, Huai-Yu

    2015-01-01

    Wheat stripe rust (Puccinia striiformis f. sp. tritici, Pst), is one of the most serious diseases of wheat (Triticum aestivum L.) worldwide. To gain a better understanding of the protective mechanism against stripe rust at the adult plant stage, the differences in photosystem II and antioxidant enzymatic systems between susceptible and resistant wheat in response to stripe rust disease (P. striiformis) were investigated. We found that chlorophyll fluorescence and the activities of the antioxidant enzymes were higher in resistant wheat than in susceptible wheat after stripe rust infection. Compared with the susceptible wheat, the resistant wheat accumulated a higher level of D1 protein and a lower level of reactive oxygen species after infection. Furthermore, our results demonstrate that D1 and light-harvesting complex II (LHCII) phosphorylation are involved in the resistance to stripe rust in wheat. The CP29 protein was phosphorylated under stripe rust infection, like its phosphorylation in other monocots under environmental stresses. More extensive damages occur on the thylakoid membranes in the susceptible wheat compared with the resistant wheat. The findings provide evidence that thylakoid protein phosphorylation and antioxidant enzyme systems play important roles in plant responses and defense to biotic stress.

  1. Characterization of Novel Gene Yr79 and Four Additional Quantitative Trait Loci for All-Stage and High-Temperature Adult-Plant Resistance to Stripe Rust in Spring Wheat PI 182103.

    Science.gov (United States)

    Feng, Junyan; Wang, Meinan; See, Deven R; Chao, Shiaoman; Zheng, Youliang; Chen, Xianming

    2018-04-25

    Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important disease of wheat worldwide. Exploring new resistance genes is essential for breeding resistant wheat cultivars. PI 182103, a spring wheat landrace originally from Pakistan, has shown a high level of resistance to stripe rust in fields for many years, but genes for resistance to stripe rust in the variety have not been studied. To map the resistance gene(s) in PI 182103, 185 recombinant inbred lines (RILs) were developed from a cross with Avocet Susceptible (AvS). The RIL population was genotyped with simple sequence repeat (SSR) and single nucleotide polymorphism markers and tested with races PST-100 and PST-114 at the seedling stage under controlled greenhouse conditions and at the adult-plant stage in fields at Pullman and Mt. Vernon, Washington under natural infection by the stripe rust pathogen in 2011, 2012, and 2013. A total of five quantitative trait loci (QTL) were detected. QyrPI182103.wgp-2AS and QyrPI182103.wgp-3AL were detected at the seedling stage, QyrPI182103.wgp-4DL was detected only in Mt. Vernon field tests, and QyrPI182103.wgp-5BS was detected in both seedling and field tests. QyrPI182103.wgp-7BL was identified as a high-temperature adult-plant resistance gene and detected in all field tests. Interactions among the QTL were mostly additive, but some negative interactions were detected. The 7BL QTL was mapped in chromosomal bin 7BL 0.40 to 0.45 and identified as a new gene, permanently designated as Yr79. SSR markers Xbarc72 and Xwmc335 flanking the Yr79 locus were highly polymorphic in various wheat genotypes, indicating that the molecular markers are useful for incorporating the new gene for potentially durable stripe rust resistance into new wheat cultivars.

  2. Genetic effects for controlling stripe rust (Puccinia striiformis f. sp. tritici resistance in wheat through joint segregation analysis

    Directory of Open Access Journals (Sweden)

    Kalim Ullah

    2016-06-01

    Full Text Available Mixed inheritance analysis using joint segregation analysis (JSA for stripe rust (Puccinia striiformis f. sp. tritici resistance was carried out in six basic populations (P1, F1, P2, BC1, BC2 and F2 of four wheat crosses (Hashim-08 × LU-26, Farid-06 × Shafaq, Parula × Blue Silver, TD-1 × D-97603 during crop season 2009 to 2012. Genes controlling stripe rust resistance were assessed by using area under disease progress curve (AUDPC. The AUDPC was controlled by mixed two additive-dominant-epistatic major genes plus additive-dominant-epistasis of polygenes in cross Hashim-08 × LU-26 (model E, while in Farid-06 × Shafaq, it was controlled by mixed two major additive-dominant genes plus additive-dominant polygenes (model E-2. In cross Parula × Blue Silver, the AUDPC was managed by additive, dominance and epistasis of two major genes (model B-1, however, it was controlled by mixed one major gene and additive dominant polygenes in cross TD-1 × D-97603 (model D-1. Genetic variation and heritability was higher in major genes than polygene for all the crosses showing that AUDPC was mainly controlled by major genes. The genetic behavior of the AUDPC revealed that stripe rust resistance was controlled by mixed interaction of one to two major genes plus polygenes.

  3. [Genetic analysis and molecular mapping of stripe rust resistance gene in a restore line of Thermo-Photo sensitive hybrid wheat MR168].

    Science.gov (United States)

    Ren, Yong; Li, Sheng-Rong; Li, Jun; Zhou, Qiang; DU, Xiao-Ying; Li, Tai-Jun; Yang, Wu-Yun; Zheng, You-Liang

    2011-11-01

    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 wheat SSR markers.Five SSR markers on chromosome 1BS including Xgwm18, Xbarc187, Xwmc269, Xgwm273, and Xwmc406 were linked with YrMR168. The resistance gene was closely linked to Xgwm18 and Xbarc187 with the genetic distances of 1.9 and 2.4 cM, respectively. Xgwm18 and Xbarc187 could be used for molecular marker assisted selection of YrMR168 in hybrid wheat breeding program.

  4. Wheat rusts in the United States in 2016

    Science.gov (United States)

    In 2016, 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 State...

  5. Screening of wheat germplasm for the source of resistance against leaf and stripe rust under climatic conditions in Bhakkar

    International Nuclear Information System (INIS)

    Bhatti, M.A.; Burhan, M.; Shahzad, M.A.; Aslam, M.

    2009-01-01

    A field experiment was conducted to assess the level of resistance and susceptibility against stripe and leaf rust of wheat at Arid Zone Research 1, Institute, Bhakkar during, Rabi 2009, One hundred wheat genotypes were sown in second week of November. Each test line/variety of planted in two rows of 2 meter reach will two row of Morocco after every three entries to increase the disease pressure, fest lines/ varieties were inoculated thrice with highly susceptible Morocco and two most virulent Lr-26 and Lr-23 patho type. Out of eighty four test entries/varieties screened against le leaf rust, 5 exhibited resistant 21 moderately susceptible, 20 susceptible, 28 moderately resistant and 10 were highly susceptible. The present investigation indicated that there was no highly resistant lines/variety with zero disease severity. On the other hand, as regards stripe rust, out of thirty seven lines/varieties only two lines were susceptible to disease, Among other lines/ varieties, 12 resistant, 11 moderately resistant, 6 moderately susceptible and 2 susceptible against disease. Four (4) lines /varieties proved as highly resistant with zero disease severity.

  6. Molecular cytogenetic characterization and stripe rust response of a trigeneric hybrid involving Triticum, Psathyrostachys, and Thinopyrum.

    Science.gov (United States)

    Kang, Houyang; Zeng, Jian; Xie, Quan; Tao, Shan; Zhong, Meiyu; Zhang, Haiqin; Fan, Xing; Sha, Lina; Xu, Lili; Zhou, Yonghong

    2012-05-01

    Trigeneric hybrids offer opportunities to transfer alien traits into cultivated wheat. In this study, a new trigeneric hybrid involving species of Triticum, Psathyrostachys, and Thinopyrum was synthesized by crossing Triticum aestivum L. (wheat)--Thinopyrum intermedium (Host) Barkworth & D.R. Dewey amphiploid Zhong 3 with wheat--Psathyrostachys huashanica Keng ex Kuo amphiploid PHW-SA. Crossability of the two amphiploids was 19.74%, and the fertility of the hybrid was 16.20%. The mean meiotic configuration of the trigeneric hybrid (2n=56) was 13.06 I+17.24 IIring+3.73 IIrod+0.28 III+0.04 IV. GISH analysis indicated that the trigeneric F1 had seven P. huashanica chromosomes and seven Th. intermedium chromosomes. The mean chromosome numbers of F2, F3, and F4 progenies were 2n=49.24, 2n=48.13, and 2n=46.78, respectively, a gradual decrease. GISH analysis revealed that most F2 and F3 plants had 2–10 Th. intermedium chromosomes and 0–4 P. huashanica chromosomes. In the F4 progenies, 1–7 Th. intermedium chromosomes were labeled, but no P. huashanica chromosomes were detected. It seems that Th. intermedium chromosomes are more likely than P. huashanica chromosomes to be transmitted to the progenies. The stripe rust response of PHW-SA was expressed in the F1 and some F2 and F3 progenies. The trigeneric hybrid could be a useful bridge for transfering P. huashanica and Th. intermedium chromosomes to common wheat.

  7. Constructing Physical and Genomic Maps for Puccinia striiformis f. sp. tritici, the Wheat Stripe Rust Pathogen, by Comparing Its EST Sequences to the Genomic Sequence of P. graminis f. sp. tritici, the Wheat Stem Rust Pathogen

    OpenAIRE

    Jinbiao Ma; Xianming Chen; Meinan Wang; Zhensheng Kang

    2009-01-01

    The wheat stripe rust fungus, Puccinia striiformis f. sp. tritici (Pst), does not have a known alternate host for sexual reproduction, which makes it impossible to study gene linkages through classic genetic and molecular mapping approaches. In this study, we compared 4,219 Pst expression sequence tags (ESTs) to the genomic sequence of P. graminis f. sp. tritici (Pgt), the wheat stem rust fungus, using BLAST searches. The percentages of homologous genes varied greatly among different Pst libr...

  8. Host status of false brome grass to the leaf rust fungus Puccinia brachypodii and the stripe rust fungus P. Striiformis

    NARCIS (Netherlands)

    Barbieri, M.; Marcel, T.C.; Niks, R.E.

    2011-01-01

    Purple false brome grass (Brachypodium distachyon) has recently emerged as a model system for temperate grasses and is also a potential model plant to investigate plant interactions with economically important pathogens such as rust fungi. We determined the host status of five Brachypodium species

  9. Mining centuries old in-situ conserved Turkish wheat landraces for grain yield and stripe rust resistance genes

    Directory of Open Access Journals (Sweden)

    Deepmala Sehgal

    2016-11-01

    Full Text Available Wheat landraces in Turkey are an important genetic resource for wheat improvement. An exhaustive five-year (2009-2014 effort made by the International Winter Wheat Improvement Programme (IWWIP a cooperative program between the Ministry of Food, Agriculture and Livestock of Turkey, the International Center for Maize and Wheat Improvement (CIMMYT and the International Center for Agricultural Research in the Dry Areas (ICARDA, led to the collection and documentation of around 2,000 landrace populations from 55 provinces throughout Turkey. This study reports the genetic characterization of a subset of bread wheat landraces collected in 2010 from 11 diverse provinces using genotyping-by-sequencing (GBS technology. The potential of this collection to identify loci determining grain yield and stripe rust resistance via genome-wide association (GWA analysis was explored. A high genetic diversity (diversity index = 0.260 and a moderate population structure based on highly inherited spike traits was revealed in the panel. The linkage disequilibrium decayed at 10 cM across the whole genome and was slower as compared to other landrace collections. In addition to previously reported QTL, GWA analysis also identified new candidate genomic regions for stripe rust resistance, grain yield and spike productivity components. New candidate genomic regions reflect the potential of this landrace collection to further increase genetic diversity in elite germplasm.

  10. 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.

  11. Wheat hypersensitive-induced reaction genes TaHIR1 and TaHIR3 are involved in response to stripe rust fungus infection and abiotic stresses.

    Science.gov (United States)

    Duan, Yinghui; Guo, Jun; Shi, Xuexia; Guan, Xiangnan; Liu, Furong; Bai, Pengfei; Huang, Lili; Kang, Zhensheng

    2013-02-01

    KEY MESSAGE : TaHIR1 and TaHIR3 play positive roles in resistance to the stripe rust fungus via inducing HR and regulating defense-related genes, but are negatively regulated by various abiotic stimuli. Plant hypersensitive-induced reaction (HIR) genes are known to be associated with the hypersensitive response and disease defense. In wheat, two HIR genes, TaHIR1 and TaHIR3, have been identified and found to be up-regulated after infection with the stripe rust fungus. Here, we further determined their roles in defense against abiotic stresses and the stripe rust pathogen, Puccinia striiformis f. sp. tritici. TaHIR1 and TaHIR3 proteins were localized in the plasma membrane of tobacco cells. The expression of TaHIR1 and TaHIR3 was reduced by the environmental stimuli, including low temperature, drought, and high salinity stresses. In addition, the expression of TaHIR1 and TaHIR3 was down-regulated by exogenously applied ethrel and abscisic acid, whereas expression was not affected by treatments with salicylic acid and methyl jasmonate. Furthermore, barley stripe mosaic virus-induced gene silencing of TaHIR1 and TaHIR3 reduced resistance in wheat cultivar Suwon11 against an avirulent stripe rust pathotype CYR23 and area of necrotic cells neighboring the infection sites, and altered the expression levels of defense-related genes. These results suggest that TaHIR1 and TaHIR3 function positively in the incompatible interaction of wheat-stripe rust fungus, but exhibit negative transcriptional response to abiotic stresses.

  12. Saturation Mapping of a Major Effect QTL for Stripe Rust Resistance on Wheat Chromosome 2B in Cultivar Napo 63 Using SNP Genotyping Arrays

    Directory of Open Access Journals (Sweden)

    Dejun Han

    2017-04-01

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

  13. 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. The ...

  14. Rust scoring guide

    NARCIS (Netherlands)

    Anonymous,

    1986-01-01

    This brief guide for identifying rust diseases of smaill grain cereals contains color photos depicting the growth stages of small grain cereal crops and provides instructions for recording rust severity and field response for stripe rust (Puccinia striiformis), stem rust (P. graminis), and leaf rust

  15. Rust scoring guide

    OpenAIRE

    Anonymous

    1986-01-01

    This brief guide for identifying rust diseases of smaill grain cereals contains color photos depicting the growth stages of small grain cereal crops and provides instructions for recording rust severity and field response for stripe rust (Puccinia striiformis), stem rust (P. graminis), and leaf rust (P. recondita).

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Zijin Zhang

    Full Text Available 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.

  18. Genome-wide association mapping reveals a rich genetic architecture of stripe rust resistance loci in emmer wheat (Triticum turgidum ssp. dicoccum).

    Science.gov (United States)

    Liu, Weizhen; Maccaferri, Marco; Chen, Xianming; Laghetti, Gaetano; Pignone, Domenico; Pumphrey, Michael; Tuberosa, Roberto

    2017-11-01

    SNP-based genome scanning in worldwide domesticated emmer germplasm showed high genetic diversity, rapid linkage disequilibrium decay and 51 loci for stripe rust resistance, a large proportion of which were novel. Cultivated emmer wheat (Triticum turgidum ssp. dicoccum), one of the oldest domesticated crops in the world, is a potentially rich reservoir of variation for improvement of resistance/tolerance to biotic and abiotic stresses in wheat. Resistance to stripe rust (Puccinia striiformis f. sp. tritici) in emmer wheat has been under-investigated. Here, we employed genome-wide association (GWAS) mapping with a mixed linear model to dissect effective stripe rust resistance loci in a worldwide collection of 176 cultivated emmer wheat accessions. Adult plants were tested in six environments and seedlings were evaluated with five races from the United States and one from Italy under greenhouse conditions. Five accessions were resistant across all experiments. The panel was genotyped with the wheat 90,000 Illumina iSelect single nucleotide polymorphism (SNP) array and 5106 polymorphic SNP markers with mapped positions were obtained. A high level of genetic diversity and fast linkage disequilibrium decay were observed. In total, we identified 14 loci associated with field resistance in multiple environments. Thirty-seven loci were significantly associated with all-stage (seedling) resistance and six of them were effective against multiple races. Of the 51 total loci, 29 were mapped distantly from previously reported stripe rust resistance genes or quantitative trait loci and represent newly discovered resistance loci. Our results suggest that GWAS is an effective method for characterizing genes in cultivated emmer wheat and confirm that emmer wheat is a rich source of stripe rust resistance loci that can be used for wheat improvement.

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

    Directory of Open Access Journals (Sweden)

    Jindong Liu

    Full Text Available 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.

  20. The development of quick, robust, quantitative phenotypic assays for describing the host-nonhost landscape to stripe rust.

    Science.gov (United States)

    Dawson, Andrew M; Bettgenhaeuser, Jan; Gardiner, Matthew; Green, Phon; Hernández-Pinzón, Inmaculada; Hubbard, Amelia; Moscou, Matthew J

    2015-01-01

    Nonhost resistance is often conceptualized as a qualitative separation from host resistance. Classification into these two states is generally facile, as they fail to fully describe the range of states that exist in the transition from host to nonhost. This poses a problem when studying pathosystems that cannot be classified as either host or nonhost due to their intermediate status relative to these two extremes. In this study, we investigate the efficacy of the Poaceae-stripe rust (Puccinia striiformis Westend.) interaction for describing the host-nonhost landscape. First, using barley (Hordeum vulgare L.) and Brachypodium distachyon (L.) P. Beauv. We observed that macroscopic symptoms of chlorosis and leaf browning were associated with hyphal colonization by P. striiformis f. sp. tritici, respectively. This prompted us to adapt a protocol for visualizing fungal structures into a phenotypic assay that estimates the percent of leaf colonized. Use of this assay in intermediate host and intermediate nonhost systems found the frequency of infection decreases with evolutionary divergence from the host species. Similarly, we observed that the pathogen's ability to complete its life cycle decreased faster than its ability to colonize leaf tissue, with no incidence of pustules observed in the intermediate nonhost system and significantly reduced pustule formation in the intermediate host system as compared to the host system, barley-P. striiformis f. sp. hordei. By leveraging the stripe rust pathosystem in conjunction with macroscopic and microscopic phenotypic assays, we now hope to dissect the genetic architecture of intermediate host and intermediate nonhost resistance using structured populations in barley and B. distachyon.

  1. Cytogenetic study and stripe rust response of the derivatives from a wheat - Thinopyrum intermedium - Psathyrostachys huashanica trigeneric hybrid.

    Science.gov (United States)

    Kang, Hou-Yang; Tang, Lin; Li, Dai-Yan; Diao, Cheng-Dou; Zhu, Wei; Tang, Yao; Wang, Yi; Fan, Xing; Xu, Li-Li; Zeng, Jian; Sha, Li-Na; Yu, Xiao-Fang; Zhang, Hai-Qin; Zhou, Yong-Hong

    2017-05-01

    To transfer multiple desirable alien genes into common wheat, we previously reported a new trigeneric hybrid synthesized by crossing a wheat - Thinopyrum intermedium partial amphiploid with wheat - Psathyrostachys huashanica amphiploid. Here, the meiotic behavior, chromosome constitution, and stripe rust resistance of F 5 derivatives from the wheat - Th. intermedium - P. huashanica trigeneric hybrid were studied. Cytological analysis indicated the F 5 progenies had chromosome numbers of 42-50 (average 44.96). The mean meiotic configuration was 1.28 univalents, 21.74 bivalents, 0.04 trivalents, and 0.02 tetravalents per pollen mother cell. In 2n = 42 lines, the average pairing configuration was 0.05 I + 19.91 II (ring) + 1.06 II (rod) + 0.003 IV, suggesting these lines were cytologically stable. Most lines with 2n = 43, 44, 46, 48, or 50, bearing a high frequency of univalents or multivalents, showed abnormal meiotic behavior. Genomic in situ hybridization karyotyping results revealed that 25 lines contained 1-7 Th. intermedium chromosomes, but no P. huashanica chromosomes were found among the 27 self-pollinated progenies. At meiosis, univalents (1-5) possessing Th. intermedium hybridization signals were detected in 19 lines. Bivalents (1-3) expressing fluorescence signals were observed in 12 lines. Importantly, 21 lines harbored wheat - Th. intermedium chromosomal translocations with various alien translocation types. Additionally, two homozygous lines, K13-668-10 and K13-682-12, possessed a pair of wheat - Th. intermedium small fragmental translocations. Compared with the recurrent parent Zhong 3, most lines showed high resistance to the stripe rust (Puccinia striiformis f. sp. tritici) pathogens prevalent in China, including race V26/Gui22. This paper reports a highly efficient technical method for inducing alien translocation between wheat and Th. intermedium by trigeneric hybridization. These lines might be potentially valuable germplasm resources for further

  2. The development of quick, robust, quantitative phenotypic assays for describing the host-nonhost landscape to stripe rust

    Directory of Open Access Journals (Sweden)

    Andrew Marc Dawson

    2015-10-01

    Full Text Available Nonhost resistance is often conceptualized as a qualitative separation from host resistance. Classification into these two states is generally facile, as they fail to fully describe the range of states that exist in the transition from host to nonhost. This poses a problem when studying pathosystems that cannot be classified as either host or nonhost due to their intermediate status relative to these two extremes. In this study, we investigate the efficacy of the Poaceae-stripe rust (Puccinia striiformis Westend. interaction for describing the host-nonhost landscape. First, using barley (Hordeum vulgare L. and Brachypodium distachyon (L. P. Beauv. we observed that macroscopic symptoms of chlorosis and leaf browning were associated with hyphal colonization by P. striiformis f. sp. tritici, respectively. This prompted us to adapt a protocol for visualizing fungal structures into a phenotypic assay that estimates the percent of leaf colonized. Use of this assay in intermediate host and intermediate nonhost systems found the frequency of infection decreases with evolutionary divergence from the host species. Similarly, we observed that the pathogen’s ability to complete its life cycle decreased faster than its ability to colonize leaf tissue, with no incidence of pustules observed in the intermediate nonhost system and significantly reduced pustule formation in the intermediate host system as compared to the host system, barley-P. striiformis f. sp. hordei. By leveraging the stripe rust pathosystem in conjunction with macroscopic and microscopic phenotypic assays, we now hope to dissect the genetic architecture of intermediate host and intermediate nonhost resistance using structured populations in barley and B. distachyon.

  3. Identification of expressed genes during compatible interaction between stripe rust (Puccinia striiformis and wheat using a cDNA library

    Directory of Open Access Journals (Sweden)

    Huang Lili

    2009-12-01

    Full Text Available Abstract Background Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst, is one of the most destructive diseases of wheat worldwide. To establish compatibility with the host, Pst forms special infection structures to invade the plant with minimal damage to host cells. Although compatible interaction between wheat and Pst has been studied using various approaches, research on molecular mechanisms of the interaction is limited. The aim of this study was to develop an EST database of wheat infected by Pst in order to determine transcription profiles of genes involved in compatible wheat-Pst interaction. Results Total RNA, extracted from susceptible infected wheat leaves harvested at 3, 5 and 8 days post inoculation (dpi, was used to create a cDNA library, from which 5,793 ESTs with high quality were obtained and clustered into 583 contigs and 2,160 singletons to give a set of 2,743 unisequences (GenBank accessions: GR302385 to GR305127. The BLASTx program was used to search for homologous genes of the unisequences in the GenBank non-redundant protein database. Of the 2,743 unisequences, 52.8% (the largest category were highly homologous to plant genes; 16.3% to fungal genes and 30% of no-hit. The functional classification of all ESTs was established based on the database entry giving the best E-value using the Bevan's classification categories. About 50% of the ESTs were significantly homologous to genes encoding proteins with known functions; 20% were similar to genes encoding proteins with unknown functions and 30% did not have significant homology to any sequence in the database. The quantitative real-time PCR (qRT-PCR analysis determined the transcription profiles and their involvement in the wheat-Pst interaction for seven of the gene. Conclusion The cDNA library is useful for identifying the functional genes involved in the wheat-Pst compatible interaction, and established a new database for studying Pst pathogenesis genes

  4. Role of Alternate Hosts in Epidemiology and Pathogen Variation of Cereal Rusts.

    Science.gov (United States)

    Zhao, Jie; Wang, Meinan; Chen, Xianming; Kang, Zhensheng

    2016-08-04

    Cereal rusts, caused by obligate and biotrophic fungi in the genus Puccinia, are important diseases that threaten world food security. With the recent discovery of alternate hosts for the stripe rust fungus (Puccinia striiformis), all cereal rust fungi are now known to be heteroecious, requiring two distinct plant species serving as primary or alternate hosts to complete their sexual life cycle. The roles of the alternate hosts in disease epidemiology and pathogen variation vary greatly from species to species and from region to region because of different climatic and cropping conditions. We focus this review on rust fungi of small grains, mainly stripe rust, stem rust, leaf rust, and crown rust of wheat, barley, oat, rye, and triticale, with emphases on the contributions of alternate hosts to the development and management of rust diseases.

  5. Isolation and molecular cytogenetic characterization of a wheat - Leymus mollis double monosomic addition line and its progenies with resistance to stripe rust.

    Science.gov (United States)

    Yang, Xiaofei; Li, Xin; Wang, Changyou; Chen, Chunhuan; Tian, Zengrong; Ji, Wanquan

    2017-12-01

    A common wheat - Leymus mollis (2n = 4x = 28, NsNsXmXm) double monosomic addition line, M11003-4-3-8/13/15 (2n = 44 = 42T.a + L.m2 + L.m3), with stripe rust resistance was developed (where T.a represents Triticum aestivum chromosome, L.m represents L. mollis chromosome, and L.m2/3 represents L. mollis chromosome of homoeologous groups 2 and 3). The progenies of line M11003-4-3-8/13/15 were characterized by cytological observation, specific molecular markers, fluorescence in situ hybridization (FISH), and genomic in situ hybridization (GISH). Among the progenies, there existed five different types (I, II, III, IV, and V) of chromosome constitution, the formulas of which were 2n = 44 = 42T.a + 1L.m2 + 1L.m3, 2n = 43 = 42T.a + 1L.m2, 2n = 43 = 42T.a + 1L.m3, 2n = 42 = 42T.a, and 2n = 44 = 42T.a + 2L.m2, respectively. Field disease screening showed that types I and III showed high resistance to stripe rust, while types II, IV, and V were susceptible. Leymus mollis was almost immune to stripe rust, whereas the wheat parent, cultivar 7182, was susceptible. Therefore, we concluded that the stripe rust resistance originated from L. mollis. These various lines could be further fully exploited as important disease resistance materials to enrich wheat genetic resources.

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

    International Nuclear Information System (INIS)

    Wang, Y.J.; Wang, C.Y.; Zhang, H.

    2015-01-01

    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)

  7. A change in temperature modulates defence to yellow (stripe) rust in wheat line UC1041 independently of resistance gene Yr36.

    Science.gov (United States)

    Bryant, Ruth R M; McGrann, Graham R D; Mitchell, Alice R; Schoonbeek, Henk-Jan; Boyd, Lesley A; Uauy, Cristobal; Dorling, Steve; Ridout, Christopher J

    2014-01-08

    Rust diseases are of major importance in wheat production worldwide. With the constant evolution of new rust strains and their adaptation to higher temperatures, consistent and durable disease resistance is a key challenge. Environmental conditions affect resistance gene performance, but the basis for this is poorly understood. Here we show that a change in day temperature affects wheat resistance to Puccinia striiformis f. sp tritici (Pst), the causal agent of yellow (or stripe) rust. Using adult plants of near-isogenic lines UC1041 +/- Yr36, there was no significant difference between Pst percentage uredia coverage in plants grown at day temperatures of 18°C or 25°C in adult UC1041 + Yr36 plants. However, when plants were transferred to the lower day temperature at the time of Pst inoculation, infection increased up to two fold. Interestingly, this response was independent of Yr36, which has previously been reported as a temperature-responsive resistance gene as Pst development in adult UC1041 -Yr36 plants was similarly affected by the plants experiencing a temperature reduction. In addition, UC1041 -Yr36 plants grown at the lower temperature then transferred to the higher temperature were effectively resistant and a temperature change in either direction was shown to affect Pst development up to 8 days prior to inoculation. Results for seedlings were similar, but more variable compared to adult plants. Enhanced resistance to Pst was observed in seedlings of UC1041 and the cultivar Shamrock when transferred to the higher temperature. Resistance was not affected in seedlings of cultivar Solstice by a temperature change in either direction. Yr36 is effective at 18°C, refining the lower range of temperature at which resistance against Pst is conferred compared to previous studies. Results reveal previously uncharacterised defence temperature sensitivity in the UC1041 background which is caused by a change in temperature and independently of Yr36. This novel

  8. 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.

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

    Science.gov (United States)

    Ling, Peng; Wang, Meinan; Chen, Xianming; Campbell, Kimberly Garland

    2007-06-04

    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. 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. The full-length cDNA library is useful in identifying functional genes of P. striiformis.

  10. Genetic analysis of rust resistance genes in global wheat cultivars: an overview

    International Nuclear Information System (INIS)

    Aktar-Uz-Zaman, Md; Tuhina-Khatun, Mst; Hanafi, Mohamed Musa; Sahebi, Mahbod

    2017-01-01

    Rust is the most devastating fungal disease in wheat. Three rust diseases, namely, leaf or brown rust caused by Puccinia triticina Eriks, stem or black rust caused by Puccinia graminis f. sp. tritici West, and stripe or yellow rust caused by Puccinia striiformis f. Tritici Eriks, are the most economically significant and common diseases among global wheat cultivars. Growing cultivars resistant to rust is the most sustainable, cost-effective and environmentally friendly approach for controlling rust diseases. To date, more than 187 rust resistance genes (80 leaf rust, 58 stem rust and 49 stripe rust) have been derived from diverse wheat or durum wheat cultivars and the related wild species using different molecular methods. This review provides a detailed discussion of the different aspects of rust resistance genes, their primitive sources, their distribution in global wheat cultivars and the importance of durable resistant varieties for controlling rust diseases. This information will serve as a foundation for plant breeders and geneticists to develop durable rust-resistant wheat varieties through marker-assisted breeding or gene pyramiding

  11. New Rust Disease of Korean Willow (Salix koreensis) Caused by Melampsora yezoensis, Unrecorded Pathogen in Korea.

    Science.gov (United States)

    Yun, Yeo Hong; Ahn, Geum Ran; Yoon, Seong Kwon; Kim, Hoo Hyun; Son, Seung Yeol; Kim, Seong Hwan

    2016-12-01

    During the growing season of 2015, leaf specimens with yellow rust spots were collected from Salix koreensis Andersson, known as Korean willow, in riverine areas in Cheonan, Korea. The fungus on S. koreensis was identified as the rust species, Melampsora yezoensis , based on the morphology of urediniospores observed by light and scanning electron microscopy, and the molecular properties of the internal transcribed spacer rDNA region. Pathogenicity tests confirmed that the urediniospores are the causal agent of the rust symptoms on the leaves and young stems of S. koreensis . Here, we report a new rust disease of S. koreensis caused by the rust fungus, M. yezoensis , a previously unrecorded rust pathogen in Korea.

  12. 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.

  13. Rust urine after intense hand drumming is caused by extracorpuscular hemolysis.

    Science.gov (United States)

    Tobal, Diego; Olascoaga, Alicia; Moreira, Gabriela; Kurdián, Melania; Sanchez, Fernanda; Roselló, Maria; Alallón, Walter; Martinez, Francisco Gonzalez; Noboa, Oscar

    2008-07-01

    During Carnival, groups of > or =60 drummers go drumming with their hands and marching for periods of 2 to 4 h. The objective of this study was to determine the frequency and type of urinary abnormalities after candombe drumming and to evaluate possible pathogenic mechanisms. For analysis of pathogenic mechanisms, a group of individuals were prospectively evaluated before and after candombe drumming. Candombe drummers were recruited in January 2006, 1 wk before prolonged drumming. After clinical evaluation, urine and blood samples were obtained before and immediately after drumming. Forty-five healthy individuals (four women and 41 men), median age 31 yr (14 to 56), were evaluated. Predrumming urine and plasma samples were obtained for 30 individuals. Nineteen (42%) of 45 had a previous history of rust urine emission temporally related with candombe drumming. After drumming, 18 of 26 showed urine abnormalities; six of 26 showed rust urine, eight of 26 had microhematuria, and seven of 26 had proteinuria >1 g/L. The candombe drummers who showed rust urine after heavy drumming presented significantly higher levels of lactate dehydrogenase and total bilirubin when compared with those without urine abnormalities. Haptoglobin was significantly lower in the rust urine group. Fragmented red cells were observed in the blood smear of individuals with rust urine. Rust urine after drumming was associated with previous episodes of rust urine and glucosuria. Taken together, these data confirm that rust urine is caused by extracorpuscular hemolysis.

  14. 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.

  15. 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

    . The sudden change was explained by the appearance of an exotic and aggressive Pst race that attacked most of the triticale varieties grown at that time, resulting in yield losses of 50-100% for organic farmers. At present, Tulus is the most widely grown triticale variety in Denmark. Although originally......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...... resistant it was susceptible under field conditions in March 2012. All Pst isolates from Tulus, obtained from multiple locations, were identified as the ‘Kranich’-race, and were avirulent on Tulus under experimental conditions. In May and June 2012 Tulus recovered on a country-wide scale and was resistant...

  16. Characterization of molecular diversity and genome-wide mapping of loci associated with resistance to stripe rust and stem rust in Ethiopian bread wheat accessions

    OpenAIRE

    Muleta, Kebede T.; Rouse, Matthew N.; Rynearson, Sheri; Chen, Xianming; Buta, Bedada G.; Pumphrey, Michael O.

    2017-01-01

    Background The narrow genetic basis of resistance in modern wheat cultivars and the strong selection response of pathogen populations have been responsible for periodic and devastating epidemics of the wheat rust diseases. Characterizing new sources of resistance and incorporating multiple genes into elite cultivars is the most widely accepted current mechanism to achieve durable varietal performance against changes in pathogen virulence. Here, we report a high-density molecular characterizat...

  17. Constructing Physical and Genomic Maps for Puccinia striiformis f. sp. tritici, the Wheat Stripe Rust Pathogen, by Comparing Its EST Sequences to the Genomic Sequence of P. graminis f. sp. tritici, the Wheat Stem Rust Pathogen.

    Science.gov (United States)

    Ma, Jinbiao; Chen, Xianming; Wang, Meinan; Kang, Zhensheng

    2009-01-01

    The wheat stripe rust fungus, Puccinia striiformis f. sp. tritici (Pst), does not have a known alternate host for sexual reproduction, which makes it impossible to study gene linkages through classic genetic and molecular mapping approaches. In this study, we compared 4,219 Pst expression sequence tags (ESTs) to the genomic sequence of P. graminis f. sp. tritici (Pgt), the wheat stem rust fungus, using BLAST searches. The percentages of homologous genes varied greatly among different Pst libraries with 54.51%, 51.21%, and 13.61% for the urediniospore, germinated urediniospore, and haustorial libraries, respectively, with an average of 33.92%. The 1,432 Pst genes with significant homology with Pgt sequences were grouped into physical groups corresponding to 237 Pgt supercontigs. The physical relationship was demonstrated by 12 pairs (57%), out of 21 selected Pst gene pairs, through PCR screening of a Pst BAC library. The results indicate that the Pgt genome sequence is useful in constructing Pst physical maps.

  18. Constructing Physical and Genomic Maps for Puccinia striiformis f. sp. tritici, the Wheat Stripe Rust Pathogen, by Comparing Its EST Sequences to the Genomic Sequence of P. graminis f. sp. tritici, the Wheat Stem Rust Pathogen

    Directory of Open Access Journals (Sweden)

    Jinbiao Ma

    2009-01-01

    Full Text Available The wheat stripe rust fungus, Puccinia striiformis f. sp. tritici (Pst, does not have a known alternate host for sexual reproduction, which makes it impossible to study gene linkages through classic genetic and molecular mapping approaches. In this study, we compared 4,219 Pst expression sequence tags (ESTs to the genomic sequence of P. graminis f. sp. tritici (Pgt, the wheat stem rust fungus, using BLAST searches. The percentages of homologous genes varied greatly among different Pst libraries with 54.51%, 51.21%, and 13.61% for the urediniospore, germinated urediniospore, and haustorial libraries, respectively, with an average of 33.92%. The 1,432 Pst genes with significant homology with Pgt sequences were grouped into physical groups corresponding to 237 Pgt supercontigs. The physical relationship was demonstrated by 12 pairs (57%, out of 21 selected Pst gene pairs, through PCR screening of a Pst BAC library. The results indicate that the Pgt genome sequence is useful in constructing Pst physical maps.

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

    Science.gov (United States)

    Soybean rust, caused by the fungal pathogen P. pachyrhizi, has been reported in 10 African countries since the first report in Uganda in 1996. In 2016, a severe epidemic caused “clouds” of urediniospores to be observed when walking through fields in mid-October 2016 in Jimma Ethiopia. In the first ...

  20. Reaction of some soybean mutant lines to natural rust fungus caused by (phakopsora pachyrhizi SYD)

    International Nuclear Information System (INIS)

    Rivai Ratma

    1988-01-01

    Reaction of some soybean mutant lines to natural rust fungus caused by (Phakopsora pachyrhizi SYD). Eleven soybean mutant lines of orba variety derived from gamma fungus disease in the wet season 1985/86 at the experimental station of Citayam, Bogor. Based on IWGSR rating system, soybean mutant lines No 18/Psj was moderately resistant to rust fungus disease. The other mutant lines, 14/PsJ, 15/PsJ, 19/PsJ, 20/PsJ, 106/PsJ, 102/PsJ, 111/PsJ, 118/PsJ, 119/PsJ and 220/PsJ were susceptible. (author). 11 refs

  1. Reaction of some soybean mutant lines to natural rust fungus caused by (phakopsora pachyrhizi syd)

    International Nuclear Information System (INIS)

    Ratma, R.

    1988-01-01

    Reaction of some soybean mutant lines to natural rust fungus caused by (phakopsora pachyhizi syd). Eleven soybean mutant lines of orba variety derived from gamma fungus disease in the wet season 1985/86 at the experimental station of Citayam, Bogor. Based on IWGSR rating system, soybean mutant lines No 18/PsJ was moderately resistant to rust fungus disease. The other mutant lines, 14/PsJ, 15/PsJ, 20/PsJ, 102/PsJ, 106/PsJ, 111/PsJ, 118/PsJ, 119/PsJ and 220/PsJ were susceptible. (author). 4 figs.; 8 refs

  2. Next generation sequencing provides rapid access to the genome of Puccinia striiformis f. sp. tritici, the causal agent of wheat stripe rust.

    Directory of Open Access Journals (Sweden)

    Dario Cantu

    Full Text Available BACKGROUND: The wheat stripe rust fungus (Puccinia striiformis f. sp. tritici, PST is responsible for significant yield losses in wheat production worldwide. In spite of its economic importance, the PST genomic sequence is not currently available. Fortunately Next Generation Sequencing (NGS has radically improved sequencing speed and efficiency with a great reduction in costs compared to traditional sequencing technologies. We used Illumina sequencing to rapidly access the genomic sequence of the highly virulent PST race 130 (PST-130. METHODOLOGY/PRINCIPAL FINDINGS: We obtained nearly 80 million high quality paired-end reads (>50x coverage that were assembled into 29,178 contigs (64.8 Mb, which provide an estimated coverage of at least 88% of the PST genes and are available through GenBank. Extensive micro-synteny with the Puccinia graminis f. sp. tritici (PGTG genome and high sequence similarity with annotated PGTG genes support the quality of the PST-130 contigs. We characterized the transposable elements present in the PST-130 contigs and using an ab initio gene prediction program we identified and tentatively annotated 22,815 putative coding sequences. We provide examples on the use of comparative approaches to improve gene annotation for both PST and PGTG and to identify candidate effectors. Finally, the assembled contigs provided an inventory of PST repetitive elements, which were annotated and deposited in Repbase. CONCLUSIONS/SIGNIFICANCE: The assembly of the PST-130 genome and the predicted proteins provide useful resources to rapidly identify and clone PST genes and their regulatory regions. Although the automatic gene prediction has limitations, we show that a comparative genomics approach using multiple rust species can greatly improve the quality of gene annotation in these species. The PST-130 sequence will also be useful for comparative studies within PST as more races are sequenced. This study illustrates the power of NGS for

  3. First report of Phakopsora pachyrhizi on soybean causing rust in Tanzania

    Science.gov (United States)

    Phakopsora pachyrhizi Syd. was reported on legume hosts other than soybean in Tanzania as early as 1979. Soybean rust (SBR), caused by P. pachyrhizi, was first reported on soybean in Africa in Uganda in 1996, and its introduction into Africa was proposed to occur through urediniospores blowing from ...

  4. First Report of Orange Rust of Sugarcane caused by Puccinia kuehnii in Ecuador

    Science.gov (United States)

    Orange rust, Puccinia kuehnii (W. Krüger) E.J. Butler, is an important disease of sugarcane (complex hybrid of Saccharum L. species) that causes yield losses, and impacts breeding programs. Initially confined to the Asia-Oceania region (5), P. kuehnii was reported in Florida in June 2007 (2) and lat...

  5. 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...

  6. Effects of planting density and the composition of wheat cultivar mixtures on stripe rust: an analysis taking into account limits to the replication of controls.

    Science.gov (United States)

    Garrett, K A; Mundt, C C

    2000-12-01

    ABSTRACT The effect of plant density on disease is not well understood in populations of a single host plant genotype and has been studied even less in mixtures of host genotypes. We performed an experiment to evaluate the effect of wheat planting density on infection by Puccinia striiformis in experimental plots with a single wheat genotype and in plots with two genotypes making up a range of frequencies. Stripe rust severity in single-genotype plots increased with planting density in 1997 but decreased with planting density in 1998. Disease in host mixtures was compared to the weighted mean of disease levels in the corresponding single-genotype plots. The design of the field experiment included limited replication of these reference treatments (that is, there was not a unique pair of single-genotype plots for each mixture plot); therefore, we devised an analysis based on collapsing the data into independent mean observations. Disease reduction due to host diversity was less when one genotype predominated than when both host genotypes were present at nearly equal frequencies. The greatest mean host-diversity effect for reduced disease was at the intermediate planting density of 250 seeds per m(2).

  7. Characterization of a pathogenesis-related thaumatin-like protein gene TaPR5 from wheat induced by stripe rust fungus.

    Science.gov (United States)

    Wang, Xiaojie; Tang, Chunlei; Deng, Lin; Cai, Gaolei; Liu, Xinying; Liu, Bo; Han, Qingmei; Buchenauer, Heinrich; Wei, Guorong; Han, Dejun; Huang, Lili; Kang, Zhensheng

    2010-05-01

    Pathogenesis-related (PR) proteins, induced in plants in response to various biotic and abiotic stresses, have been assumed to play a role in plant defense system. Proteins of the PR5 family, also named thaumatin-like proteins (TLPs), have been detected in numerous plant species. In this research, a novel PR5 gene, designated as TaPR5, was isolated and characterized from wheat leaves (cv. Suwon 11) infected by the stripe rust pathotype CY23 (incompatible interaction) using the rapid amplification of cDNA ends (RACE). TaPR5 was predicted to encode a protein of 173 amino acids with an estimated molecular mass of 17.6 kDa and a theoretical pI of 4.64. The deduced amino acid sequence of TaPR5 showed a significant sequence similarity with PR5 and TLPs from barley and other plants and contained a putative signal peptide at the amino terminus. Southern blot analysis indicated that TaPR5 is coded by a single-copy gene. Quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed that TaPR5 transcript is significantly induced and upregulated in the incompatible interaction while in the compatible interaction a relative low level of the transcript was detected. TaPR5 was also induced by phytohormones (SA, JA and ABA) and stress stimuli (wounding, cold temperature and high salinity). Using an assay of onion epidermal cells indicated accumulation of TaPR5 protein in the apoplast. The immunocytochemical method showed that the TaPR5 protein was detected on cell walls of wheat leaves in the incompatible interaction at markedly higher labeling density compared with the compatible interaction.

  8. 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)

  9. 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.

  10. The Lr34 adult plant rust resistance gene provides seedling resistance in durum wheat without senescence

    OpenAIRE

    Rinaldo, Amy; Gilbert, Brian; Boni, Rainer; Krattinger, Simon G.; Singh, Davinder; Park, Robert F.; Lagudah, Evans; Ayliffe, Michael

    2017-01-01

    Summary The hexaploid wheat (Triticum aestivum) adult plant resistance gene, Lr34/Yr18/Sr57/Pm38/Ltn1, provides broad?spectrum resistance to wheat leaf rust (Lr34), stripe rust (Yr18), stem rust (Sr57) and powdery mildew (Pm38) pathogens, and has remained effective in wheat crops for many decades. The partial resistance provided by this gene is only apparent in adult plants and not effective in field?grown seedlings. Lr34 also causes leaf tip necrosis (Ltn1) in mature adult plant leaves when ...

  11. Stem rust of small grains and grasses caused by Puccinia graminis.

    Science.gov (United States)

    Leonard, Kurt J; Szabo, Les J

    2005-03-01

    shown to infect 74 species in 34 genera in artificial inoculations of seedlings, but only 28 of those species belonging to eight genera were known to be natural hosts of the fungus. Other formae speciales of P. graminis have narrower host ranges than P. graminis f. sp. tritici. Disease symptoms: Infections in cereals or grasses occur mainly on stems and leaf sheaths, but occasionally they may be found on leaf blades and glumes as well. The first macroscopic symptom is usually a small chlorotic fleck, which appears a few days after infection. About 8-10 days after infection, a pustule several millimetres long and a few millimetres wide is formed by rupture of the host epidermis from pressure of a mass of brick-red urediniospores produced in the infection. These uredinial pustules are generally linear or diamond shaped and may enlarge up to 10 mm long. The powdery masses of urediniospores appear similar to rust spots on a weathered iron surface. With age, the infection ceases production of brick-red urediniospores and produces a layer of black teliospores in their place, causing the stems of heavily infected plants to appear blackened late in the season.

  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 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. First Report of Soybean Rust, Caused by Phakopsora pachyrhizi, on Kudzu (Pueraria montana var. lobata) in Illinois

    Science.gov (United States)

    Soybean rust, caused by Phakopsora pachyrhizi, was first observed on soybean (Glycine max) in the continental United States in Louisiana in 2004, and on kudzu (Pueraria montana var. lobata) in the United States in 2005. Kudzu is a leguminous weed that is prevalent in the southern United States with ...

  14. Real-time PCR detection of Puccinia chrysanthemi causing brown rust of chrysanthemum

    Science.gov (United States)

    Fungi responsible for rust diseases are among the most challenging organisms to identify, as many identification keys are based on host identity. In the U.S., numerous rust fungi are quarantine-significant plant pathogens. As such, accurate identification is crucial to prevent the inadvertent introd...

  15. 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...

  16. 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

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

    Science.gov (United States)

    Nemri, Adnane; Saunders, Diane G O; Anderson, Claire; Upadhyaya, Narayana M; Win, Joe; Lawrence, Gregory J; Jones, David A; Kamoun, Sophien; Ellis, Jeffrey G; Dodds, Peter N

    2014-01-01

    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 most 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 optimize 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 analyzed 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 infection on their

  18. 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.

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

    Science.gov (United States)

    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. Growth-chamber studies demonstrated wheat rust control at multiple plant growth stages with a glyphosate spray dose typically recommended for weed control. Rust control was absent in formulation controls without glyphosate, dependent on systemic glyphosate concentrations in leaf tissues, and not mediated through induction of four common systemic acquired resistance genes. A field test with endemic stripe rust inoculum confirmed the activities of glyphosate pre- and postinfestation. Preliminary greenhouse studies also demonstrated that application of glyphosate in glyphosate-resistant soybeans suppressed Asian soybean rust, caused by Phakopsora pachyrhizi. PMID:16293685

  20. Yellow Rust Epidemics Worldwide Were Caused by Pathogen Races from Divergent Genetic Lineages

    DEFF Research Database (Denmark)

    Ali, Sajid; Rodriguez Algaba, Julian; Thach, Tine

    2017-01-01

    We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s) or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed that these epide......We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s) or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed...

  1. 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...

  2. Yellow rust protection on the wheat

    OpenAIRE

    Hanzalová, Alena; Bartoš, Pavel

    2015-01-01

    Heavy incidence of yellow rust in the years 2014 and 2015 has proved high deleterious effects of this rust. For this reason this publication deals with yellow rust on wheat. Rusts on wheat cause losses every year. In the years of an epidemic yield can be decreased by more than a half. Epidemics of stem rust and yellow rust occur in irregular intervals. Leaf rust causes damage every year particularly in central and southern part of Moravia. Chemical control limits yield losses, however in the ...

  3. Rapid detection of Puccinia triticina causing leaf rust of wheat by PCR and loop mediated isothermal amplification.

    Science.gov (United States)

    Manjunatha, C; Sharma, Sapna; Kulshreshtha, Deepika; Gupta, Sangeeta; Singh, Kartar; Bhardwaj, Subhash C; Aggarwal, Rashmi

    2018-01-01

    Leaf rust of wheat caused by Puccinia triticina has significant impact on wheat production worldwide. Effective and quick detection methodologies are required to mitigate yield loss and time constraints associated with monitoring and management of leaf rust of wheat. In the present study, detection of P. triticina has been simplified by developing a rapid, reliable, efficient and visual colorimetric method i.e., loop mediated isothermal amplification of DNA (LAMP). Based on in silico analysis of P. triticina genome, PTS68, a simple sequence repeat was found highly specific to leaf rust fungus. A marker (PtRA68) was developed and its specificity was validated through PCR technique which gave a unique and sharp band of 919 bp in P. triticina pathotypes only. A novel gene amplification method LAMP which enables visual detection of pathogen by naked eye was developed for leaf rust pathogen. A set of six primers was designed from specific region of P. triticina and conditions were optimised to complete the observation process in 60 minutes at 65o C. The assay developed in the study could detect presence of P. triticina on wheat at 24 hpi (pre-symptomatic stage) which was much earlier than PCR without requiring thermal cycler. Sensitivity of LAMP assay developed in the study was 100 fg which was more sensitive than conventional PCR (50 pg) and equivalent to qPCR (100 fg). The protocol developed in the study was utilized for detection of leaf rust infected samples collected from different wheat fields. LAMP based colorimetric detection assay showed sky blue color in positive reaction and violet color in negative reaction after addition of 120 μM hydroxyl napthol blue (HNB) solution to reaction mixture. Similarly, 0.6 mg Ethidium bromide/ml was added to LAMP products, placed on transilluminator to witness full brightness in positive reaction and no such brightness could be seen in negative reaction mixture. Further, LAMP products spread in a ladder like banding pattern in

  4. EPIDEMIOLOGY OF WHEAT LEAF AND STEM RUST IN THE CENTRAL GREAT PLAINS OF THE USA.

    Science.gov (United States)

    Eversmeyer, M. G.; Kramer, C. L.

    2000-01-01

    Wheat (Triticum aestivum L) is grown throughout the grasslands from southern Mexico into the prairie provinces of Canada, a distance of nearly 4200 km. The total area seeded to wheat varies considerably each year; however, from 28 to 32 million ha are planted in the Great Plains of the United States alone. Generally in the central Great Plains, an area from central Texas through central Nebraska, 15 million ha are seeded to winter wheat each year. A wide range of environmental conditions exist throughout this area that may affect the development and final severity of wheat leaf rust (caused by Puccinia triticina L), stripe rust (caused by P. striiformis), and stem rust (caused by P. graminis Pers. f. sp tritici) epidemics and the subsequent reduction in wheat yields. Variation in severity of rust epidemics in this area depends on differences in crop maturity at the time of infection by primary inoculum, host resistance used, and environmental conditions. The interrelationships among time, host, pathogen and environment are complex, and studying the interactions is very difficult. Historically, cultivars with new or different leaf rust resistance genes become ineffective after several years of large-scale production within the Great Plains, and then cultivars carrying new or different resistance genes must be developed and released into production. This is the typical "boom and bust" cycle of the cereal rust resistance genes in the central Great Plains.

  5. 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. ...

  6. Rhexocercosporidium panacis sp. nov., a new anamorphic species causing rusted root of ginseng (Panax [corrected] quinquefolius).

    Science.gov (United States)

    Reeleder, R D

    2007-01-01

    A new species of the anamorphic genus Rhexocercosporidium is described. Isolates of a Rhex-Rhexocercosporidium sp. were obtained from ginseng (Panax quinquefolius) roots with symptoms of rusted root. These isolates were found to be genetically and morphologically distinct from the only described species in this genus, R. carotae. Sequence data from the ribosomal DNA region spanning the internal transcribed spacers 1 and 2 and from a portion of the 3-tubulin gene of the ginseng Rhexocercosporidium were compared to those of R. carotae. Parsimony analyses of sequence data showed that R. carotae and the ginseng isolates belonged to distinct but closely related clades. Conidia of a typical ginseng isolate were significantly shorter and possessed fewer septa than R. carotae but shared rhexolytic secession of conidia with R. carotae. The binomial Rhexocercosporidium panacis is proposed to accommodate isolates of this genus that are associated with the rusted root disease.

  7. Characterization of a novel wheat NAC transcription factor gene involved in defense response against stripe rust pathogen infection and abiotic stresses.

    Science.gov (United States)

    Xia, Ning; Zhang, Gang; Liu, Xin-Ying; Deng, Lin; Cai, Gao-Lei; Zhang, Yi; Wang, Xiao-Jie; Zhao, Jie; Huang, Li-Li; Kang, Zhen-Sheng

    2010-12-01

    Proteins encoded by the NAC gene family constitute one of the largest plant-specific transcription factors, which have been identified to play many important roles in both abiotic and biotic stress adaptation, as well as in plant development regulation. In the current paper, a full-length cDNA sequence of a novel wheat NAC gene, designated as TaNAC4, was isolated using in silico cloning and the reverse transcription PCR (RT-PCR) methods. TaNAC4 sharing high homology with rice OsNAC4 gene was predicted to encode a protein of 308 amino acid residues, which contained a plant-specific NAC domain in the N-terminus. Transient expression analysis indicated that the deduced TaNAC4 protein was localized in the nucleus of onion epidemical cells. Yeast one-hybrid assay revealed that the C-terminal region of the TaNAC4 protein had transcriptional activity. The expression of TaNAC4 was largely higher in the wheat seedling roots, than that in leaves and stems. TaNAC4 transcript in wheat leaves was induced by the infection of strip rust pathogen, and also by exogenous applied methyl jasmonate (MeJA), ABA and ethylene. However, salicylic acid (SA) had no obvious effect on TaNAC4 expression. Environmental stimuli, including high salinity, wounding, and low-temperature also induced TaNAC4 expression. These results indicate that this novel TaNAC4 gene functions as a transcriptional activator involved in wheat response to biotic and abiotic stresses.

  8. Determination of rust resistance genes in pakistani bread wheats

    International Nuclear Information System (INIS)

    Qamar, M.; Ahmad, S.D.; Rabbani, M.A.; Shinwari, Z.K.

    2014-01-01

    Stripe and leaf rusts are the major constraints to bread wheat production in Pakistan. Molecular markers were used to investigate the presence of leaf rust and stripe rust resistance gene cluster Lr34/Yr18 and stem rust resistance gene Sr2 in 52 Pakistani bread wheat cultivars/lines. PCR amplification of DNA fragments using DNA marker csLV-34 showed that 13 of the studied cultivars/lines, namely 03FJ26, NR 337, NR 339, NR 347, NR 350, Manthar, Margalla 99, Iqbal 2000, Saleem 2000, Wafaq 2001, Marwat 2001, Pirsabak 2004 and Fareed 2006 carry leaf rust and stripe rust resistance genes Lr34/Yr18. Stem rust resistance gene Sr2 was observed in 36 Pakistani spring wheat cultivars/lines using stm560.3tgag marker. The slow rusting gene Sr2 needs to be combined with additional stem rust resistance genes to establish durable resistance against Ug99 in modern wheat cultivars. Low frequency of Lr34/Yr18 was found in Pakistani wheats. This gene cluster needs to be incorporated into Pakistani wheats for durable rust resistance. (author)

  9. The Lr34 adult plant rust resistance gene provides seedling resistance in durum wheat without senescence.

    Science.gov (United States)

    Rinaldo, Amy; Gilbert, Brian; Boni, Rainer; Krattinger, Simon G; Singh, Davinder; Park, Robert F; Lagudah, Evans; Ayliffe, Michael

    2017-07-01

    The hexaploid wheat (Triticum aestivum) adult plant resistance gene, Lr34/Yr18/Sr57/Pm38/Ltn1, provides broad-spectrum resistance to wheat leaf rust (Lr34), stripe rust (Yr18), stem rust (Sr57) and powdery mildew (Pm38) pathogens, and has remained effective in wheat crops for many decades. The partial resistance provided by this gene is only apparent in adult plants and not effective in field-grown seedlings. Lr34 also causes leaf tip necrosis (Ltn1) in mature adult plant leaves when grown under field conditions. This D genome-encoded bread wheat gene was transferred to tetraploid durum wheat (T. turgidum) cultivar Stewart by transformation. Transgenic durum lines were produced with elevated gene expression levels when compared with the endogenous hexaploid gene. Unlike nontransgenic hexaploid and durum control lines, these transgenic plants showed robust seedling resistance to pathogens causing wheat leaf rust, stripe rust and powdery mildew disease. The effectiveness of seedling resistance against each pathogen correlated with the level of transgene expression. No evidence of accelerated leaf necrosis or up-regulation of senescence gene markers was apparent in these seedlings, suggesting senescence is not required for Lr34 resistance, although leaf tip necrosis occurred in mature plant flag leaves. Several abiotic stress-response genes were up-regulated in these seedlings in the absence of rust infection as previously observed in adult plant flag leaves of hexaploid wheat. Increasing day length significantly increased Lr34 seedling resistance. These data demonstrate that expression of a highly durable, broad-spectrum adult plant resistance gene can be modified to provide seedling resistance in durum wheat. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  10. Tracking the distribution of Puccinia psidii genotypes that cause rust disease on diverse myrtaceous trees and shrubs

    Science.gov (United States)

    Amy L. Ross-Davis; Rodrigo N. Graca; Acelino C. Alfenas; Tobin L. Peever; Jack W. Hanna; Janice Y. Uchida; Rob D. Hauff; Chris Y. Kadooka; Mee-Sook Kim; Phil G. Cannon; Shigetou Namba; Nami Minato; Sofia Simeto; Carlos A. Perez; Min B. Rayamajhi; Mauricio Moran; D. Jean Lodge; Marcela Arguedas; Rosario Medel-Ortiz; M. Armando Lopez-Ramirez; Paula Tennant; Morag Glen; Ned B. Klopfenstein

    2014-01-01

    Puccinia psidii Winter (Basidiomycota, Uredinales) is a biotrophic rust fungus that was first reported in Brazil from guava in 1884 (Psidium guajava; Winter 1884) and later from eucalypt in 1912 (Joffily 1944). Considered to be of neotropical origin, the rust has also been reported to infect diverse myrtaceous hosts elsewhere in South America, Central America, the...

  11. Inheritance and bulked segregant analysis of leaf rust and stem rust resistance genes in eight durum wheat genotypes

    Science.gov (United States)

    Leaf rust, caused by Puccinia triticina (Pt) and stem rust caused by Puccinia graminis f. sp. tritici (Pgt) are important diseases of durum wheat. This study determined the inheritance and genomic locations of leaf rust resistance (Lr) genes to Pt-race BBBQJ and stem rust resistance (Sr) genes to Pg...

  12. Yellow Rust Epidemics Worldwide Were Caused by Pathogen Races from Divergent Genetic Lineages

    Directory of Open Access Journals (Sweden)

    Sajid Ali

    2017-06-01

    Full Text Available We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed that these epidemics were often driven by races from few but highly divergent genetic lineages. PstS1 was predominant in North America; PstS2 in West Asia and North Africa; and both PstS1 and PstS2 in East Africa. PstS4 was prevalent in Northern Europe on triticale; PstS5 and PstS9 were prevalent in Central Asia; whereas PstS6 was prevalent in epidemics in East Africa. PstS7, PstS8 and PstS10 represented three genetic lineages prevalent in Europe. Races from other lineages were in low frequencies. Virulence to Yr9 and Yr27 was common in epidemics in Africa and Asia, while virulence to Yr17 and Yr32 were prevalent in Europe, corresponding to widely deployed resistance genes. The highest diversity was observed in South Asian populations, where frequent recombination has been reported, and no particular race was predominant in this area. The results are discussed in light of the role of invasions in shaping pathogen population across geographical regions. The results emphasized the lack of predictability of emergence of new races with high epidemic potential, which stresses the need for additional investments in population biology and surveillance activities of pathogens on global food crops, and assessments of disease vulnerability of host varieties prior to their deployment at larger scales.

  13. Yellow Rust Epidemics Worldwide Were Caused by Pathogen Races from Divergent Genetic Lineages

    Science.gov (United States)

    Ali, Sajid; Rodriguez-Algaba, Julian; Thach, Tine; Sørensen, Chris K.; Hansen, Jens G.; Lassen, Poul; Nazari, Kumarse; Hodson, David P.; Justesen, Annemarie F.; Hovmøller, Mogens S.

    2017-01-01

    We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s) or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed that these epidemics were often driven by races from few but highly divergent genetic lineages. PstS1 was predominant in North America; PstS2 in West Asia and North Africa; and both PstS1 and PstS2 in East Africa. PstS4 was prevalent in Northern Europe on triticale; PstS5 and PstS9 were prevalent in Central Asia; whereas PstS6 was prevalent in epidemics in East Africa. PstS7, PstS8 and PstS10 represented three genetic lineages prevalent in Europe. Races from other lineages were in low frequencies. Virulence to Yr9 and Yr27 was common in epidemics in Africa and Asia, while virulence to Yr17 and Yr32 were prevalent in Europe, corresponding to widely deployed resistance genes. The highest diversity was observed in South Asian populations, where frequent recombination has been reported, and no particular race was predominant in this area. The results are discussed in light of the role of invasions in shaping pathogen population across geographical regions. The results emphasized the lack of predictability of emergence of new races with high epidemic potential, which stresses the need for additional investments in population biology and surveillance activities of pathogens on global food crops, and assessments of disease vulnerability of host varieties prior to their deployment at larger scales. PMID:28676811

  14. 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.

  15. Molecular characterization of the rDNA-ITS sequence and a PCR diagnostic technique for Pileolaria terebinthi, the cause of pistachio rust

    Directory of Open Access Journals (Sweden)

    Hossein ALAEI

    2013-01-01

    Full Text Available Eleven samples of the most important pistachio rust (caused by Pileolaria terebinthi (DC. Cast.,, which causes disease on Beneh (Pistacia atlantica Desf. subsp. mutica (Fisch. & Mey. Rech. F and Kasoor (Pistacia khinjuk Stocks., were collected from herbarium specimens and pistachio fields at the Pistachio Research Institute in Rafsanjan, Iran. The complete sequences of ribosomal DNA internal transcribed spacers ITS1 and ITS2 (rDNA ITS from the samples were determined and analysed. In general, very little rDNA ITS sequence variation was observed between rDNA ITS sequences of P. terebinthi samples. The length of the PCR fragments was 621 bp (for ITS1F-ITS4 and 1177 bp (for ITS1F-rust1, and consisted of 67 bp at the 3 ́ end of 18S rDNA, 93 bp of ITS1 region, 154 bp of 5.8S rDNA, 246 bp of the ITS2 region, 57 bp (for ITS1F-ITS4 and 613 bp (for ITS1F-rust1 at the 5 ́ end of the 28S rDNA. Restriction fragment length polymorphisms (RFLPs of the rDNA-ITS region were used to identify Pileolaria terebinthi. Three strong bands of 105, 134 and 381 bp and five bands of 105, 134, 200, 301 and 437 bp are observed for the fragment of “ITS1F-ITS4” and “ITS1F-rust1”, respectively. A PCR-RFLP diagnostic technique provided effective identification of the species by a unique pattern with the specific restriction enzyme XapI (ApoI.

  16. Sources of resistance to yellow rust and stem rust in wheat-alien introgressions

    OpenAIRE

    Rahmatov, Mahbubjon

    2013-01-01

    Wheat is the staple food and the main source of caloric intake in most developing countries, and thereby an important source in order to maintain food security for the growing populations in those countries. Stem rust Puccinia graminis f. sp. tritici, and yellow rust P. striiformis f. sp. tritici of wheat continues to cause severe damage locally and globally, thereby contributing to food insecurity. In this paper biology and taxonomy of stem rust and yellow rust, breeding for resistance, util...

  17. 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.

  18. Postulation of rust resistance genes in Nordic spring wheat genotypes and identification of widely effective sources of resistance against the Australian rust flora.

    Science.gov (United States)

    Randhawa, Mandeep; Bansal, Urmil; Lillemo, Morten; Miah, Hanif; Bariana, Harbans

    2016-11-01

    Wild relatives, landraces and cultivars from different geographical regions have been demonstrated as the sources of genetic variation for resistance to rust diseases. This study involved assessment of diversity for resistance to three rust diseases among a set of Nordic spring wheat cultivars. These cultivars were tested at the seedling stage against several pathotypes of three rust pathogens in the greenhouse. All stage stem rust resistance genes Sr7b, Sr8a, Sr12, Sr15, Sr17, Sr23 and Sr30, and leaf rust resistance genes Lr1, Lr3a, Lr13, Lr14a, Lr16 and Lr20 were postulated either singly or in different combinations among these cultivars. A high proportion of cultivars were identified to carry linked rust resistance genes Sr15 and Lr20. Although 51 cultivars showed variation against Puccinia striiformis f. sp. tritici (Pst) pathotypes used in this study, results were not clearly contrasting to enable postulation of stripe rust resistance genes in these genotypes. Stripe rust resistance gene Yr27 was postulated in four cultivars and Yr1 was present in cultivar Zebra. Cultivar Tjalve produced low stripe rust response against all Pst pathotypes indicating the presence either of a widely effective resistance gene or combination of genes with compensating pathogenic specificities. Several cultivars carried moderate to high level of APR to leaf rust and stripe rust. Seedling stem rust susceptible cultivar Aston exhibited moderately resistant to moderately susceptible response, whereas other cultivars belonging to this class were rated moderately susceptible or higher. Molecular markers linked with APR genes Yr48, Lr34/Yr18/Sr57, Lr68 and Sr2 detected the presence of these genes in some genotypes.

  19. Commandra Blister Rust

    Science.gov (United States)

    David W. Johnson

    1986-01-01

    Commandra blister rust is a disease of hard pines that is caused by a fungus growing in the inner bark. The fungus (Cronartium commandrae Pk.) has a complex life cycle. It infects hard pines but needs an alternate host, an unrelated plant, to spread from one pine to another.

  20. First report of Puccinia psidii caused rust-disease epiphytotic on the invasive shrub Rhodomyrtus tomentosa in Florida

    Science.gov (United States)

    Rhodomyrtus tomentosa (Aiton) Hassk. (downy-rose myrtle, Family: Myrtaceae) of south Asian origin is an invasive shrub that has formed monotypic stands in Florida. During the winter and spring of 2010-2012, a rust disease of epiphytotic proportion was observed on young foliage, stem terminals and i...

  1. Rust disease of eucalypts, caused by Puccinia psidii, did not originate via host jump from guava in Brazil

    Science.gov (United States)

    Rodrigo N. Graca; Amy L. Ross-Davis; Ned B. Klopfenstein; Mee-Sook Kim; Tobin L. Peever; Phil G. Cannon; Cristina P. Aun; Eduardo G. Mizubuti; Acelino C. Alfenas

    2013-01-01

    The rust fungus, Puccinia psidii, is a devastating pathogen of introduced eucalypts (Eucalyptus spp.) in Brazil where it was first observed in 1912. This pathogen is hypothesized to be endemic to South and Central America and to have first infected eucalypts via a host jump from native guava (Psidium guajava). Ten microsatellite markers were used to genotype 148 P....

  2. First report of Puccinia psidii caused rust disease epiphytotic on the invasive shrub Rhodomyrtus tomentosa in Florida

    Science.gov (United States)

    M. B. Rayamajhi; P. D. Pratt; N. B. Klopfenstein; A. L. Ross-Davis; L. Rodgers

    2013-01-01

    Rhodomyrtus tomentosa (Aiton) Hassk. (downy-rose myrtle, family: Myrtaceae), of South Asian origin, is an invasive shrub that has formed monotypic stands in Florida (3). During the winter and spring of 2010 through 2012, a rust disease of epiphytotic proportion was observed on young foliage, stem terminals, and immature fruits of this shrub in natural areas of Martin...

  3. Molecular and genetic study of wheat rusts | Le Maitre | African ...

    African Journals Online (AJOL)

    Molecular and genetic study of wheat rusts. ... Puccinia triticina, Puccinia graminis and Puccinia striiformis cause leaf, stem and yellow rust, respectively. Wheat rusts can cause ... Breeding resistant cultivars is a long process and requires an accurate picture of the current and future pathogen population. Differentiation of ...

  4. Molecular and genetic study of wheat rusts | Le Maitre | African ...

    African Journals Online (AJOL)

    Puccinia triticina, Puccinia graminis and Puccinia striiformis cause leaf, stem and yellow rust, respectively. Wheat rusts can cause losses as high as 70%. The rusts ability to evolve fungicide resistance has resulted in the use of resistant cultivars as the primary method of control. Breeding resistant cultivars is a long process ...

  5. Winnie Rust

    African Journals Online (AJOL)

    Owner

    Om te trek is om jou kortstondig in 'n liminale staat te bevind. Nóg by jou vertrekpunt, nóg by jou uiteindelike bestemming, sonder die geborgenheid wat hierdie twee vaste plekke kwansuis bied. In 'n hele aantal opsigte is Trek van Winnie Rust 'n beskrywing van verskil- lende liminale state. Dit is egter nie 'n reisverhaal met ...

  6. Seeing Rust

    Science.gov (United States)

    2004-01-01

    The rust color of the Martian landscape is apparent in this low-resolution thumbnail image taken by the panoramic camera on the Mars Exploration Rover Spirit. This image is part of a larger image currently stored onboard the rover in its memory.

  7. 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.

  8. Utilization of the cropgro-soybean model to estimate yield loss caused by Asian rust in cultivars with different cycle

    Directory of Open Access Journals (Sweden)

    Rafael de Ávila Rodrigues

    2012-01-01

    Full Text Available In recent years, crop models have increasingly been used to simulate agricultural features. The DSSAT (Decision Support System for Agrotechnology Transfer is an important tool in modeling growth; however, one of its limitations is related to the unaccounted-for effect of diseases. Therefore, the goals of this study were to calibrate and validate the CSM CROPGRO-Soybean for the soybean cultivars M-SOY 6101 and MG/BR 46 (Conquista, analyze the performance and the effect of Asian soybean rust on these cultivars under the environmental conditions of Viçosa, Minas Gerais, Brazil. The experimental data for the evaluation, testing, and adjustment of the genetic coefficients for the cultivars, M-SOY 6101 and MG/BR 46 (Conquista, were obtained during the 2006/2007, 2007/2008 and 2009/2010 growing seasons. GLUE (Generalized Likelihood Uncertainty Estimation was used for the estimation of the genetic coefficients, and pedotransfer functions have been utilized to estimate the physical characteristics of the soil. For all of the sowing dates, the early season cultivar, M-SOY 6101, exhibited a lower variance in yield, which represents more stability with regard to the interannual climate variability, i.e., the farmers who use this cultivar will have in 50% of the crop years analyzed, a higher yield than a late-season cultivar. The MG/BR 46 (Conquista cultivar demonstrated a greater probability of obtaining higher yield in years with favorable weather conditions. However, in the presence of the Asian soybean rust, yield is heavily affected. The early cultivar, M-SOY 6101, showed a lower risk of being affected by the rust and consequently exhibited less yield loss considering the scenario D90 (condensation on the leaf surface occurs when the relative humidity is greater than or equal to 90%, for a sowing date of November 14.

  9. Development of RAPD based markers for wheat rust resistance ...

    African Journals Online (AJOL)

    Rust diseases are the major cause of low yield of wheat in Pakistan. Wheat breeders all over the world as well as in Pakistan are deriving rust resistance genes from alien species like Triticum ventricosum and introducing them in common wheat (Triticum aestivum). One such example is the introgression of rust resistance ...

  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. Phenotypic and genotypic characterization of race TKTTF of Puccinia graminis f. sp. tritici that caused a wheat stem rust epidemic in southern Ethiopia in 2013-2014

    Science.gov (United States)

    A severe stem rust epidemic occurred in southern Ethiopia during November 2013 to January 2014 with yield losses close to 100% on the most widely grown wheat cultivar, 'Digalu'. Sixty-four stem rust samples collected from the regions were analyzed. A meteorological model for airborne spore dispersal...

  12. Rust transformation/rust compatible primers

    Science.gov (United States)

    Emeric, Dario A.; Miller, Christopher E.

    1993-01-01

    Proper surface preparation has been the key to obtain good performance by a surface coating. The major obstacle in preparing a corroded or rusted surface is the complete removal of the contaminants and the corrosion products. Sandblasting has been traditionally used to remove the corrosion products before painting. However, sandblasting can be expensive, may be prohibited by local health regulations and is not applicable in every situation. To get around these obstacles, Industry developed rust converters/rust transformers and rust compatible primers (high solids epoxies). The potential use of these products for military equipment led personnel of the Belvoir Research, Development and Engineering Center (BRDEC) to evaluate the commercially available rust transformers and rust compatible primers. Prior laboratory experience with commercially available rust converters, as well as field studies in Hawaii and Puerto Rico, revealed poor performance, several inherent limitations, and lack of reliability. It was obvious from our studies that the performance of rust converting products was more dependent on the amount and type of rust present, as well as the degree of permeability of the coating, than on the product's ability to form an organometallic complex with the rust. Based on these results, it was decided that the Military should develop their own rust converter formulation and specification. The compound described in the specification is for use on a rusted surface before the application of an organic coating (bituminous compounds, primer or topcoat). These coatings should end the need for sandblasting or the removing of the adherent corrosion products. They also will prepare the surface for the application of the organic coating. Several commercially available rust compatible primers (RCP) were also tested using corroded surfaces. All of the evaluated RCP failed our laboratory tests for primers.

  13. Evaluation of rumble stripes.

    Science.gov (United States)

    2010-01-01

    The objective of this study were to: a) monitor the initial installations of rumble stripes and b) evaluate the results of rumble stripe installations. : Ten rural, two-lane road locations were selected by the Kentucky Transportation Cabinet across t...

  14. Rust disease of eucalypts, caused by Puccinia psidii, did not originate via host jump from guava in Brazil.

    Science.gov (United States)

    Graça, Rodrigo N; Ross-Davis, Amy L; Klopfenstein, Ned B; Kim, Mee-Sook; Peever, Tobin L; Cannon, Phil G; Aun, Cristina P; Mizubuti, Eduardo S G; Alfenas, Acelino C

    2013-12-01

    The rust fungus, Puccinia psidii, is a devastating pathogen of introduced eucalypts (Eucalyptus spp.) in Brazil where it was first observed in 1912. This pathogen is hypothesized to be endemic to South and Central America and to have first infected eucalypts via a host jump from native guava (Psidium guajava). Ten microsatellite markers were used to genotype 148 P. psidii samples from eucalypts and guava plus five additional myrtaceous hosts across a wide geographic range of south-eastern Brazil and Uruguay. Principal coordinates analysis, a Bayesian clustering analysis and a minimum-spanning network revealed two major genetic clusters among the sampled isolates, one associated with guava and another associated with eucalypts and three additional hosts. Multilocus genotypes infecting guava differed by multiple mutational steps at eight loci compared with those infecting eucalypts. Approximate Bayesian computation revealed that evolutionary scenarios involving a coalescence event between guava- and eucalypt-associated pathogen populations within the past 1000 years are highly unlikely. None of the analyses supported the hypothesis that eucalypt-infecting P. psidii in Brazil originated via host jump from guava following the introduction of eucalypts to Brazil approximately 185 years ago. The existence of host-associated biotypes of P. psidii in Brazil indicates that this diversity must be considered when assessing the invasive threat posed by this pathogen to myrtaceous hosts worldwide. © 2013 John Wiley & Sons Ltd.

  15. Fusiform Rust of Southern Pines

    Science.gov (United States)

    W. R. Phelps; F. L. Czabator

    1978-01-01

    Fusiform rust, caused by the fungus Cronartium fusiforme Hedg. & Hunt ex Cumm., is distributed in the Southern United States from Maryland to Florida and west to Texas and southern Arkansas. Infections by the fungus, which develops at or near the point of infection, result in tapered, spindle-shaped swells, called galls, on branches and stems of pines. (see photo...

  16. 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.

  17. 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.

  18. Lighting up superconducting stripes

    Science.gov (United States)

    Ergeçen, Emre; Gedik, Nuh

    2018-02-01

    Cuprate superconductors display a plethora of complex phases as a function of temperature and carrier concentration, the understanding of which could provide clues into the mechanism of superconductivity. For example, when about one-eighth of the conduction electrons are removed from the copper oxygen planes in cuprates such as La2‑xBaxCuO4 (LBCO), the doped holes (missing electrons) organize into one-dimensional stripes (1). The bulk superconducting transition temperature (Tc) is greatly reduced, and just above Tc, electrical transport perpendicular to the planes (along the c axis) becomes resistive, but parallel to the copper oxygen planes, resistivity remains zero for a range of temperatures (2). It was proposed a decade ago (3) that this anisotropic behavior is caused by pair density waves (PDWs); superconducting Cooper pairs exist along the stripes within the planes but cannot tunnel to the adjacent layers. On page 575 of this issue, Rajasekaran et al. (4) now report detection of this state in LBCO using nonlinear reflection of high-intensity terahertz (THz) light.

  19. Inheritance and Bulked Segregant Analysis of Leaf Rust and Stem Rust Resistance in Durum Wheat Genotypes.

    Science.gov (United States)

    Aoun, Meriem; Kolmer, James A; Rouse, Matthew N; Chao, Shiaoman; Bulbula, Worku Denbel; Elias, Elias M; Acevedo, Maricelis

    2017-12-01

    Leaf rust, caused by Puccinia triticina, and stem rust, caused by P. graminis f. sp. tritici, are important diseases of durum wheat. This study determined the inheritance and genomic locations of leaf rust resistance (Lr) genes to P. triticina race BBBQJ and stem rust resistance (Sr) genes to P. graminis f. sp. tritici race TTKSK in durum accessions. Eight leaf-rust-resistant genotypes were used to develop biparental populations. Accessions PI 192051 and PI 534304 were also resistant to P. graminis f. sp. tritici race TTKSK. The resulting progenies were phenotyped for leaf rust and stem rust response at seedling stage. The Lr and Sr genes were mapped in five populations using single-nucleotide polymorphisms and bulked segregant analysis. Five leaf-rust-resistant genotypes carried single dominant Lr genes whereas, in the remaining accessions, there was deviation from the expected segregation ratio of a single dominant Lr gene. Seven genotypes carried Lr genes different from those previously characterized in durum. The single dominant Lr genes in PI 209274, PI 244061, PI387263, and PI 313096 were mapped to chromosome arms 6BS, 2BS, 6BL, and 6BS, respectively. The Sr gene in PI 534304 mapped to 6AL and is most likely Sr13, while the Sr gene in PI 192051 could be uncharacterized in durum.

  20. Characterization and comparative analysis of the genome of Puccinia sorghi Schwein, the causal agent of maize common rust.

    Science.gov (United States)

    Rochi, Lucia; Diéguez, María José; Burguener, Germán; Darino, Martín Alejandro; Pergolesi, María Fernanda; Ingala, Lorena Romina; Cuyeu, Alba Romina; Turjanski, Adrián; Kreff, Enrique Domingo; Sacco, Francisco

    2018-03-01

    Rust fungi are one of the most devastating pathogens of crop plants. The biotrophic fungus Puccinia sorghi Schwein (Ps) is responsible for maize common rust, an endemic disease of maize (Zea mays L.) in Argentina that causes significant yield losses in corn production. In spite of this, the Ps genomic sequence was not available. We used Illumina sequencing to rapidly produce the 99.6Mbdraft genome sequence of Ps race RO10H11247, derived from a single-uredinial isolate from infected maize leaves collected in the Argentine Corn Belt Region during 2010. High quality reads were obtained from 200bppaired-end and 5000bpmate-paired libraries and assembled in 15,722 scaffolds. A pipeline which combined an ab initio program with homology-based models and homology to in planta enriched ESTs from four cereal pathogenic fungus (the three sequenced wheat rusts and Ustilago maydis) was used to identify 21,087 putative coding sequences, of which 1599 might be part of the Ps RO10H11247 secretome. Among the 458 highly conserved protein families from the euKaryotic Orthologous Groups (KOG) that occur in a wide range of eukaryotic organisms, 97.5% have at least one member with high homology in the Ps assembly (TBlastN, E-value⩽e-10) covering more than 50% of the length of the KOG protein. Comparative studies with the three sequenced wheat rust fungus, and microsynteny analysis involving Puccinia striiformis f. sp. tritici (Pst, wheat stripe rust fungus), support the quality achieved. The results presented here show the effectiveness of the Illumina strategy for sequencing dikaryotic genomes of non-model organisms and provides reliable DNA sequence information for genomic studies, including pathogenic mechanisms of this maize fungus and molecular marker design. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Induced resistance to rust disease in lentil

    International Nuclear Information System (INIS)

    Paul, Amitava; Singh, D.P.

    2006-01-01

    Considerable yield reduction in lentil is due to rust caused by Uromyces fabae. So far the sources of resistance to rust are available in the small seeded background. There is a need to develop rust resistant/tolerant bold seeded cultivars. Mutations were induced by gamma rays (10 and 15 kR) for incorporating resistance to rust in K-75(Mallika), a high yielding bold seeded, but rust susceptible cultivar at Pantnagar which is the hot spot for this disease. Dry seeds (300) were irradiated for each treatment. In M 1 generation, individual plants from each treatment were selfed and harvested separately which constituted the M 2 generation. In M 2 individual plant progenies were scored following a rating scale of 1 (Free) to 9(highly susceptible). At 15 kR dose, 8 plants were resistant (score 3.0) and 14 plants were tolerant (score 5.0) to rust, while in control and 10 kR populations, all plants were susceptible or highly susceptible having score of 7 or 9, respectively. The M 2 plants segregated in ratio of 1 resistant: 3 susceptible. The progenies of resistant/tolerant M 2 plants were bred true in the M 3 generation suggesting that the resistance to rust is controlled by one recessive gene. (author)

  2. A review of soybean rust from a South African perspective

    OpenAIRE

    J. Antony Jarvie

    2010-01-01

    This review article describes the nature of the soybean rust pathogen, its interaction with the soybean host and documents some of the history of soybean rust in South Africa. Soybean rust has affected soybean cropping in parts of South Africa since 2001. The disease causes leaf lesions, which may progress to premature defoliation and ultimately result in grain yield loss in susceptible soybean genotypes. Chemical control measures have been successfully employed to limit commercial yield loss...

  3. 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

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

    Science.gov (United States)

    Amanda L. Pendleton; Katherine E. Smith; Nicolas Feau; Francis M. Martin; Igor V. Grigoriev; Richard Hamelin; C.Dana Nelson; J.Gordon Burleigh; John M. Davis

    2014-01-01

    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...

  5. Using hierarchical clustering of secreted protein families to classify and rank candidate effectors of rust fungi

    Science.gov (United States)

    Rust fungi are obligate biotrophic pathogens causing considerable damage on crop plants. P. graminis f. sp. tritici, the causal agent of wheat stem rust, and M. larici-populina, the poplar rust pathogen, have strong deleterious impact on wheat and poplar wood production, respectively. The recently r...

  6. Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases

    Science.gov (United States)

    Jacob, Sherry R.; Srinivasan, Kalyani; Radhamani, J.; Parimalan, R.; Sivaswamy, M.; Tyagi, Sandhya; Yadav, Mamata; Kumari, Jyotisna; Deepali; Sharma, Sandeep; Bhagat, Indoo; Meeta, Madhu; Bains, N. S.; Chowdhury, A. K.; Saha, B. C.; Bhattacharya, P. M.; Kumari, Jyoti; Singh, M. C.; Gangwar, O. P.; Prasad, P.; Bharadwaj, S. C.; Gogoi, Robin; Sharma, J. B.; GM, Sandeep Kumar; Saharan, M. S.; Bag, Manas; Roy, Anirban; Prasad, T. V.; Sharma, R. K.; Dutta, M.; Sharma, Indu; Bansal, K. C.

    2016-01-01

    A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat–Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011–14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels. PMID:27942031

  7. Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases.

    Directory of Open Access Journals (Sweden)

    Sundeep Kumar

    Full Text Available A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat-Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011-14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu, a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab, a hotspot for stripe rust and at Cooch Behar (West Bengal, a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels.

  8. Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases.

    Science.gov (United States)

    Kumar, Sundeep; Archak, Sunil; Tyagi, R K; Kumar, Jagdish; Vk, Vikas; Jacob, Sherry R; Srinivasan, Kalyani; Radhamani, J; Parimalan, R; Sivaswamy, M; Tyagi, Sandhya; Yadav, Mamata; Kumari, Jyotisna; Deepali; Sharma, Sandeep; Bhagat, Indoo; Meeta, Madhu; Bains, N S; Chowdhury, A K; Saha, B C; Bhattacharya, P M; Kumari, Jyoti; Singh, M C; Gangwar, O P; Prasad, P; Bharadwaj, S C; Gogoi, Robin; Sharma, J B; Gm, Sandeep Kumar; Saharan, M S; Bag, Manas; Roy, Anirban; Prasad, T V; Sharma, R K; Dutta, M; Sharma, Indu; Bansal, K C

    2016-01-01

    A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat-Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011-14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels.

  9. 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.

  10. short communication sources of stem rust resistance in ethiopian ...

    African Journals Online (AJOL)

    Administrator

    Stem or black rust of wheat caused by the fungus Puccinia graminis f. sp. tritici Ericks and Henn (Pgt) is an important disease on wheat ... for their response to stem rust (Puccinia graminis f. sp. trictici) infection under greenhouse condition at Kulumsa. Agricultural .... are the phenotypic expression of host-pathogen interaction.

  11. RESEARCH ARTICLE Genetics and mapping of a new leaf rust ...

    Indian Academy of Sciences (India)

    Leaf rust caused by the fungus Pucciniatriticina,is one of the most widespread diseases of bread wheat (TriticumaestivumL.). Though, rust diseases have chemical control, genetic resistance in the host is the most economical and environment-friendly method. Wild relatives of wheat are reservoir of useful genes, including ...

  12. stem rust seedling resistance genes in ethiopian wheat cultivars

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Stem rust caused by Puccinia graminis f. sp. tritici is one of the major biotic limiting factors for wheat production in Ethiopia. Host plant resistance is the best option to manage stem rust from its economic and environmental points of view. Wheat cultivars are released for production without carrying race specific tests against ...

  13. White pines, blister rust, and management in the Southwest

    Science.gov (United States)

    D. A. Conklin; M Fairweather; D Ryerson; B Geils; D Vogler

    2009-01-01

    White pines in New Mexico and Arizona are threatened by the invasive disease white pine blister rust, Cronartium ribicola. Blister rust is already causing severe damage to a large population of southwestern white pine in the Sacramento Mountains of southern New Mexico. Recent detection in northern and western New Mexico suggests that a major expansion of the...

  14. Genetic analysis of resistance to soybean rust disease | Kiryowa ...

    African Journals Online (AJOL)

    Soybean rust (Phakopsora pachyrhizi Sydow.) causes the most damage of all the pathogens known to attack soybean (Glycine max. Merril). A study was conducted in Uganda to estimate the magnitude of genetic parameters controlling soybean rust resistance and to estimate narrow sense heritability of the resistance.

  15. Stem rust seedling resistance genes in Ethiopian wheat cultivars ...

    African Journals Online (AJOL)

    Stem rust caused by Puccinia graminis f. sp. tritici is one of the major biotic limiting factors for wheat production in Ethiopia. Host plant resistance is the best option to manage stem rust from its economic and environmental points of view. Wheat cultivars are released for production without carrying race specific tests against ...

  16. 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.

  17. Resistência de genótipos de soja à Phakopsora pachyrhizi Resistance of soybean genotipes of the cerrado region to rust caused by Phakopsora pachyrhizi

    Directory of Open Access Journals (Sweden)

    Luís Antônio Siqueira de Azevedo

    2007-09-01

    Full Text Available O presente trabalho teve como objetivo, quantificar a resistência à Phakopsora pachyrhizi em 50 genótipos de soja na região do cerrado. Foi conduzido em Uberlândia, MG , um experimento em casa de vegetação, durante o período de janeiro a julho de 2004. Foram avaliados os seguintes parâmetros de resistência: período latente médio, número médio de pústulas por cm² e severidade da ferrugem. Com base nesses parâmetros, calculou-se a área abaixo da curva de progresso da doença. Após, análise de variância e teste de médias que foram comparadas pelo teste de Duncan ao nível de 5% de probabilidade, utilizando-se o software ESTAT. Foram encontradas diferenças significativas entre os genótipos de soja para os parâmetros estudados. As cultivares Emgopa 313 e Monsoy 8211 apresentaram menor período latente médio, menor número de pústulas, severidade e área abaixo da curva do progresso da doença, sendo classificadas como resistentes ao patógeno no experimento realizado.The aim of the present study, was to quantify the resistance in fifty soybean genotipes of the cerrado region to the rust caused by Phakopsora pachyrhizi .One experiment in greenhouse were conducted in Uberlândia , MG from January to July 2004. Average latent period, number of pustules per cm² and disease severity were evaluated. Based on these parameters, it was calculated the area under the disease progress curve. Significant differences were found among the soybean genotipes to the three studied parameters. The cultivars Emgopa 313 and Monsoy 8211 were more resistant to Pkakopsora pachyrhizi in greenhouse experiment.

  18. Mapping of stripe rust resistance gene in an Aegilops caudata ...

    Indian Academy of Sciences (India)

    PUNEET INDER TOOR

    binding site and leucine-rich repeats (NBS-LRR) genes on wheat chromosome 5DS, NBS-LRR protein sequences were fetched from B. distachyon protein file and BLAST searched against 5DS survey sequence. Wheat contigs containing. NBS-LRR sequences were annotated to locate the posi- tions of NBS-LRR encoding ...

  19. Invasion of the striped mollusks

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Introduced to this country only five years ago, the prolific zebra mussel has infested the Great Lakes and has already begun to move into fresh waters beyond the region. Dense populations in utility water systems have caused serious problems, reducing plant efficiency and blocking lines used for cooling and fire fighting. Experts say the striped mollusk has the potential to become the industry's worst biological problem, possibly affecting 70% of US power plants. While it appears that the invader is here to stay, EPRI and others continue to develop and refine techniques to control mussel growth

  20. Demonstration of pathotype specificity in stem rust of perennial ryegrass.

    Science.gov (United States)

    Pfender, W

    2009-10-01

    Rust diseases cause significant damage in forage and seed crops of perennial ryegrass (Lolium perenne), which is highly heterozygous and heterogeneous and thus presents difficulty in genetic analysis. There has been no definitive demonstration of the existence of pathotypes for stem rust or other rusts of perennial ryegrass, although experiments with crown rust (Puccinia coronata) of this host are strongly suggestive of pathotype specificity. We made single-pustule isolates of P. graminis subsp. graminicola, and applied them individually to a set of genetically diverse, clonally propagated individuals of L. perenne. There were clear examples of different patterns of virulence among isolates across the different plant clones, including qualitative and quantitative differences in resistance. These data demonstrate the existence of pathotype specificity in stem rust of L. perenne, information which will be useful in breeding for disease resistance.

  1. Pathological and molecular characterizations of slow leaf rusting in ...

    African Journals Online (AJOL)

    Sundeep

    2012-10-18

    110012, India. 5CIMMYT South Asia, Singha Durbar Road, Kathmandu, Nepal. Accepted 5 September, 2012. Leaf rust caused by Puccinia triticina, is a globally important fungal disease of wheat (Triticum aestivum L. em. Thell) ...

  2. HOW to Identify and Control Stem Rusts of Jack Pine

    Science.gov (United States)

    Kathryn Robbins; Dale K. Smeltzer; D. W. French

    Damage to jack pine caused by rust fungi includes growth reduction, cankers, death (by girdling or wind breakage), and creation of entryways for other fungi and insects. Seedlings and saplings are more seriously affected than older trees.

  3. A review of soybean rust from a South African perspective

    Directory of Open Access Journals (Sweden)

    J. Antony Jarvie

    2010-01-01

    Full Text Available This review article describes the nature of the soybean rust pathogen, its interaction with the soybean host and documents some of the history of soybean rust in South Africa. Soybean rust has affected soybean cropping in parts of South Africa since 2001. The disease causes leaf lesions, which may progress to premature defoliation and ultimately result in grain yield loss in susceptible soybean genotypes. Chemical control measures have been successfully employed to limit commercial yield losses in South Africa; however, controlling the effects of this disease through host-resistance or tolerance mechanisms remains a long-term goal.

  4. Invasion of the striped mollusks

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    Introduced to this country only five years ago, the prolific zebra mussel has infested the Great Lakes and has already begun to move into fresh waters beyond the region. Dense populations in utility water systems have caused serious problems, reducing plant efficiency and blocking lines used for cooling and fire fighting. Experts say the striped mollusk has the potential to become the industry's worst biological problem, possibly affecting 70% of US power plants. While it appears that the invader is here to stay, EPRI and others continue to develop and refine techniques to control mussel growth. This article describes how the mollusk got here, reviews the problems it can cause and what is being done to mitigate the problems and control the growth and spread of the mollusk.

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

    DEFF Research Database (Denmark)

    Hansen, Jens Grønbech; Lassen, Poul

    A wheat rust toolbox was developed in the frame of the Borlaug Global Rust Initiative (BGRI) to support the early warning and monitoring of stem rust on a global scale. The toolbox consists of a number of databases and web applications for data management, quality control, dissemination and display...... 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://www.fao.org/agriculture/crops/rust/stem/rust......-report/en/). The Wheat rust toolbox is one of several International research platforms hosted by Aarhus University, and it uses the same ICT framework and databases as EuroWheat (www.eurowheat.org) and EuroBlight (www.EuroBlight.net). The Wheat Rust Toolbox will also serve the Global Rust Reference Centre (GRRC) as well...

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

    Science.gov (United States)

    Bettgenhaeuser, Jan; Gilbert, Brian; Ayliffe, Michael; Moscou, Matthew J.

    2014-01-01

    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. PMID:25566270

  7. Nonhost resistance to rust pathogens - a continuation of continua.

    Science.gov (United States)

    Bettgenhaeuser, Jan; Gilbert, Brian; Ayliffe, Michael; Moscou, Matthew J

    2014-01-01

    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.

  8. 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.

  9. Investigating Gene Function in Cereal Rust Fungi by Plant-Mediated Virus-Induced Gene Silencing.

    Science.gov (United States)

    Panwar, Vinay; Bakkeren, Guus

    2017-01-01

    Cereal rust fungi are destructive pathogens, threatening grain production worldwide. Targeted breeding for resistance utilizing host resistance genes has been effective. However, breakdown of resistance occurs frequently and continued efforts are needed to understand how these fungi overcome resistance and to expand the range of available resistance genes. Whole genome sequencing, transcriptomic and proteomic studies followed by genome-wide computational and comparative analyses have identified large repertoire of genes in rust fungi among which are candidates predicted to code for pathogenicity and virulence factors. Some of these genes represent defence triggering avirulence effectors. However, functions of most genes still needs to be assessed to understand the biology of these obligate biotrophic pathogens. Since genetic manipulations such as gene deletion and genetic transformation are not yet feasible in rust fungi, performing functional gene studies is challenging. Recently, Host-induced gene silencing (HIGS) has emerged as a useful tool to characterize gene function in rust fungi while infecting and growing in host plants. We utilized Barley stripe mosaic virus-mediated virus induced gene silencing (BSMV-VIGS) to induce HIGS of candidate rust fungal genes in the wheat host to determine their role in plant-fungal interactions. Here, we describe the methods for using BSMV-VIGS in wheat for functional genomics study in cereal rust fungi.

  10. 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...

  11. 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.

  12. Lr67 and Lr34 rust resistance genes have much in common – they confer broad spectrum resistance to multiple pathogens in wheat

    Science.gov (United States)

    2013-01-01

    Background Adult plant rust resistance genes Lr67 and Lr34 confer race non-specific resistance to multiple fungal pathogens of wheat. Induced, susceptible mutants were characterised for both genes. Results Three categories of Lr34 mutants were identified that were either partial susceptible, fully susceptible or hyper-susceptible to stripe rust and leaf rust. The likely impact of the mutational change on the predicted Lr34 protein correlated with differences in response to rust infection. Four independent Lr67 mutants were recovered that were susceptible to stripe rust, leaf rust and stem rust pathogens, including one possible hyper-susceptible Lr67 mutant. Conclusions Detailed study of Lr34 mutants revealed that subtle changes in resistance response to multiple pathogens were correlated with mutational changes in the predicted protein. Recovery of independent Lr67 mutants indicates that as for Lr34, a single gene at the Lr67 locus is likely to confer resistance to multiple pathogens. The infection phenotypes of Lr67 mutants closely resembled that of Lr34 mutants. PMID:23819608

  13. Two distinct classes of QTL determine rust resistance in sorghum.

    Science.gov (United States)

    Wang, Xuemin; Mace, Emma; Hunt, Colleen; Cruickshank, Alan; Henzell, Robert; Parkes, Heidi; Jordan, David

    2014-12-31

    Agriculture is facing enormous challenges to feed a growing population in the face of rapidly evolving pests and pathogens. The rusts, in particular, are a major pathogen of cereal crops with the potential to cause large reductions in yield. Improving stable disease resistance is an on-going major and challenging focus for many plant breeding programs, due to the rapidly evolving nature of the pathogen. Sorghum is a major summer cereal crop that is also a host for a rust pathogen Puccinia purpurea, which occurs in almost all sorghum growing areas of the world, causing direct and indirect yield losses in sorghum worldwide, however knowledge about its genetic control is still limited. In order to further investigate this issue, QTL and association mapping methods were implemented to study rust resistance in three bi-parental populations and an association mapping set of elite breeding lines in different environments. In total, 64 significant or highly significant QTL and 21 suggestive rust resistance QTL were identified representing 55 unique genomic regions. Comparisons across populations within the current study and with rust QTL identified previously in both sorghum and maize revealed a high degree of correspondence in QTL location. Negative phenotypic correlations were observed between rust, maturity and height, indicating a trend for both early maturing and shorter genotypes to be more susceptible to rust. The significant amount of QTL co-location across traits, in addition to the consistency in the direction of QTL allele effects, has provided evidence to support pleiotropic QTL action across rust, height, maturity and stay-green, supporting the role of carbon stress in susceptibility to rust. Classical rust resistance QTL regions that did not co-locate with height, maturity or stay-green QTL were found to be significantly enriched for the defence-related NBS-encoding gene family, in contrast to the lack of defence-related gene enrichment in multi-trait effect

  14. Exploding Stars and Stripes

    Science.gov (United States)

    2011-03-01

    The discovery of a pattern of X-ray "stripes" in the remains of an exploded star may provide the first direct evidence that a cosmic event can accelerate particles to energies a hundred times higher than achieved by the most powerful particle accelerator on Earth. This result comes from a very long observation of the Tycho supernova remnant with NASA's Chandra X-ray Observatory. It could explain how some of the extremely energetic particles bombarding the Earth, called cosmic rays, are produced. "We've seen lots of intriguing structures in supernova remnants, but we've never seen stripes before," said Kristoffer Eriksen, a postdoctoral researcher at Rutgers University who led the study. "This made us think very hard about what's happening in the blast wave of this powerful explosion." This latest study from Chandra provides support for a theory about how magnetic fields can be dramatically amplified in such blast waves. In this theory, the magnetic fields become highly tangled and the motions of the particles very turbulent near the expanding supernova shock wave at the front edge of the supernova remnant. High-energy charged particles can bounce back and forth across the shock wave repeatedly, gaining energy with each crossing. Theoretical models of the motion of the most energetic particles -- which are mostly protons -- are predicted to leave a messy network of holes and dense walls corresponding to weak and strong regions of magnetic fields, respectively. The X-ray stripes discovered by the Chandra researchers are thought to be regions where the turbulence is greater and the magnetic fields more tangled than surrounding areas, and may be the walls predicted by the theory. Electrons become trapped in these regions and emit X-rays as they spiral around the magnetic field lines. However, the regular and almost periodic pattern of the X-ray stripes was not predicted by the theory. "It was a big surprise to find such a neatly arranged set of stripes," said co

  15. Leaf rust of cultivated barley: pathology and control.

    Science.gov (United States)

    Park, Robert F; Golegaonkar, Prashant G; Derevnina, Lida; Sandhu, Karanjeet S; Karaoglu, Haydar; Elmansour, Huda M; Dracatos, Peter M; Singh, Davinder

    2015-01-01

    Leaf rust of barley is caused by the macrocyclic, heteroecious rust pathogen Puccinia hordei, with aecia reported from selected species of the genera Ornithogalum, Leopoldia, and Dipcadi, and uredinia and telia occurring on Hordeum vulgare, H. vulgare ssp. spontaneum, Hordeum bulbosum, and Hordeum murinum, on which distinct parasitic specialization occurs. Although Puccinia hordei is sporadic in its occurrence, it is probably the most common and widely distributed rust disease of barley. Leaf rust has increased in importance in recent decades in temperate barley-growing regions, presumably because of more intensive agricultural practices. Although total crop loss does not occur, under epidemic conditions yield reductions of up to 62% have been reported in susceptible varieties. Leaf rust is primarily controlled by the use of resistant cultivars, and, to date, 21 seedling resistance genes and two adult plant resistance (APR) genes have been identified. Virulence has been detected for most seedling resistance genes but is unknown for the APR genes Rph20 and Rph23. Other potentially new sources of APR have been reported, and additivity has been described for some of these resistances. Approaches to achieving durable resistance to leaf rust in barley are discussed.

  16. 78 FR 27855 - Black Stem Rust; Additions of Rust-Resistant Species and Varieties

    Science.gov (United States)

    2013-05-13

    .... APHIS-2012-0108] Black Stem Rust; Additions of Rust-Resistant Species and Varieties AGENCY: Animal and... stem rust quarantine and regulations by adding two varieties to the list of rust-resistant Berberis species and varieties and one variety to the list of rust-resistant Mahonia species and varieties. This...

  17. Genetics of leaf rust resistance in the hard red winter wheat cultivars Santa Fe and Duster

    Science.gov (United States)

    Leaf rust caused by Puccinia triticina is a common and important disease of hard red winter wheat in the Great Plains of the United States. The hard red winter wheat cultivars 'Santa Fe' and 'Duster' have had effective leaf rust resistance since their release in 2003 and 2006, respectively. Both cul...

  18. Wheat stem rust in South Africa: Current status and future research ...

    African Journals Online (AJOL)

    . In South Africa, stem rust caused by Puccinia graminis Pers. f. sp. tritici. Eriks. & E. Henn. (Pgt) is an important disease of wheat. Records of stem rust occurrence in South Africa date back to the late 1720's, when it was first discovered in the ...

  19. White pine blister rust resistance in limber pine: Evidence for a major gene

    Science.gov (United States)

    A. W. Schoettle; R. A. Sniezko; A. Kegley; K. S. Burns

    2014-01-01

    Limber pine (Pinus flexilis) is being threatened by the lethal disease white pine blister rust caused by the non-native pathogen Cronartium ribicola. The types and frequencies of genetic resistance to the rust will likely determine the potential success of restoration or proactive measures. These first extensive inoculation trials using individual tree seed collections...

  20. Current and future molecular approaches to investigate the white pine blister rust pathosystem

    Science.gov (United States)

    B. A. Richardson; A. K. M. Ekramoddoulah; J.-J. Liu; M.-S. Kim; N. B. Klopfenstein

    2010-01-01

    Molecular genetics is proving to be especially useful for addressing a wide variety of research and management questions on the white pine blister rust pathosystem. White pine blister rust, caused by Cronartium ribicola, is an ideal model for studying biogeography, genetics, and evolution because: (1) it involves an introduced pathogen; (2) it includes multiple primary...

  1. Resistance to white pine blister rust in Pinus flexilis and P

    Science.gov (United States)

    Anna W. Schoettle; Richard A. Sniezko; Angelia Kegley; Jerry Hill; Kelly S. Burns

    2010-01-01

    The non-native fungus Cronartium ribicola, that causes white pine blister rust (WPBR), is impacting or threatening limber pine, Pinus flexilis, and Rocky Mountain bristlecone pine, Pinus aristata. In the Southern Rockies, where the rust invasion is still expanding, we have the opportunity to be proactive and prepare the landscape for invasion. Genetic...

  2. Effect of fungicide on the development of wheat stem rust and yield ...

    African Journals Online (AJOL)

    Stem rust caused by Puccinia graminis f.sp tritici Erik. & E. Henn. is a highly destructive disease of wheat (Triticum aestivum L.). The effects of fungicide application on stem rust (Puccinia graminis tritici) epidemics and yield of three bread wheat varieties varying in reaction to the disease were studied in two major wheat ...

  3. Genomic dissection of nonhost resistance to wheat stem rust in Brachypodium distachyon

    Science.gov (United States)

    Wheat stem rust caused by the fungus Puccinia graminis f.sp. tritici (Pgt) is a devastating disease that has largely been controlled for decades by the deployment of resistance genes. However, new races of this pathogen have emerged that overcome many important wheat stem rust resistance genes used ...

  4. Effect of orange rust on sugarcane breeding program at canal Point

    Science.gov (United States)

    Orange rust of sugarcane (Saccharum spp. hybrids), caused by Puccinia kuehnii (W. Krüger) E.J. Butler, appeared in the Western Hemisphere ten years ago. Orange rust substantially reduces yields in susceptible sugarcane genotypes. Majority of the commercial cultivars were susceptible at the time of o...

  5. Identification of unique genetic sources of soybean rust resistance from the USDA germplasm collection

    Science.gov (United States)

    Soybean rust (SBR) is caused by the fungal pathogen Phakopsora pachyrhizi. Thus far, six rust resistance loci (Rpp1, 2, 3, 4, 5, and 6) have been reported. On the basis of field and greenhouse phenotyping assays between 2006 and 2011, we identified 75 SBR-resistant plant introductions (PIs). Crosses...

  6. Crown rust control on oats

    International Nuclear Information System (INIS)

    Frey, K.J.; Browning, J.A.; Simons, M.D.

    1976-01-01

    Attempts have been made to test the relative effectiveness of EMS treatment for inducing tolerance to crown rust among oat strains Clintland-60 of different ploidy levels. One strain of diploid and one of tetraploid oats were treated with EMS. These two strains are as susceptible to damage from crown rust as are cultivars of hexaploid oats. Multiline cultivars of oats have been shown to provide adequate protection from economic loss due to crown-rust disease in Iowa. Since 1968, eleven multiline cultivars of oats have been released from the Iowa station for use in commercial production in the midwestern USA. During the past two winter seasons, the effectiveness of multiline oat cultivars against crown-rust disease has been researched in Texas, USA, which has a ''long rust season'' of about four months, not an Iowa ''short rust season''. The protection against crown rust afforded by the multiline cultivars appeared equally good in Texas and Iowa. The seasonal productions of crown-rust spores relative to completely resistant and susceptible checks were nearly identical in both environments. Fifteen new isolines of oats have been developed for use in multiline varieties, with seed supplies sufficiently large for immediate use

  7. 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.

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

    Science.gov (United States)

    Pendleton, Amanda L; Smith, Katherine E; Feau, Nicolas; Martin, Francis M; Grigoriev, Igor V; Hamelin, Richard; Nelson, C Dana; Burleigh, J Gordon; Davis, John M

    2014-01-01

    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 16 diverse fungal species, which include 15 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.

  9. 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...

  10. 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

  11. Climate change impacts on coffee rust disease

    Science.gov (United States)

    Alfonsi, W. M. V.; Koga-Vicente, A.; Pinto, H. S.; Alfonsi, E. L., Sr.; Coltri, P. P.; Zullo, J., Jr.; Patricio, F. R.; Avila, A. M. H. D.; Gonçalves, R. R. D. V.

    2016-12-01

    Changes in climate conditions and in extreme weather events may affect the food security due to impacts in agricultural production. Despite several researches have been assessed the impacts of extremes in yield crops in climate change scenarios, there is the need to consider the effects in pests and diseases which increase losses in the sector. Coffee Arabica is an important commodity in world and plays a key role in Brazilian agricultural exports. Although the coffee crop has a world highlight, its yield is affected by several factors abiotic or biotic. The weather as well pests and diseases directly influence the development and coffee crop yield. These problems may cause serious damage with significant economic impacts. The coffee rust, caused by the fungus Hemileia vastarix,is among the diseases of greatest impact for the crop. The disease emerged in Brazil in the 70s and is widely spread in all producing regions of coffee in Brazil, and in the world. Regions with favorable weather conditions for the pathogen may exhibit losses ranging from 30% to 50% of the total grain production. The evaluation of extreme weather events of coffee rust disease in futures scenarios was carried out using the climatic data from CMIP5 models, data field of coffee rust disease incidence and, incubation period simulation data for Brazilian municipalities. Two Regional Climate Models were selected, Eta-HadGEM2-ES and Eta-MIROC5, and the Representative Concentration Pathways 8.5 w/m2 was adopted. The outcomes pointed out that in these scenarios the period of incubation tends to decrease affecting the coffee rust disease incidence, which tends to increase. Nevertheless, the changing in average trends tends to benefit the reproduction of the pathogen. Once the temperature threshold for the disease reaches the adverse conditions it may be unfavorable for the incidence.

  12. 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...

  13. Molecular Characterization of wheat stem rust races in Kenya

    Science.gov (United States)

    Stem or black rust caused by Puccinia graminis f. sp. tritici (Pgt) Erikss. & Henning causes severe losses to wheat (Triticum aestivum L.), historically threatening global wheat production. Characterizing prevalent isolates of Pgt would enhance the knowledge of population dynamics and evolution of t...

  14. Registration of eight soybean germplasm lines resistant to soybean rust

    Science.gov (United States)

    Soybean rust (SBR), caused by the fungus Phakopsora pachyrhizi Sydow is a threat to soybean [Glycine max (L.) Merr.] production worldwide. Although SBR has not caused widespread damage in North America, the crop is still threatened by the disease because most cultivars in production are susceptible...

  15. Essential Oils for Alternative Teak Rust Control

    Directory of Open Access Journals (Sweden)

    Pedro Raymundo Argüelles Osorio

    2018-03-01

    Full Text Available ABSTRACT The objectives of this study were to evaluate the effect of lemon grass, citronella grass, Mexican-tea and noni essential oils on urediniospore germination of Olivea neotectonae , the agent responsible for rust in Teak (Tectona grandis L.f.; to evaluate the phytotoxic effect of these essential oils on teak seedlings; and to evaluate the use of essential oils to control rust in teak plants when preventively and curatively applied. We found that the noni and lemon grass essential oils inhibited 100% of urediniospore germination. On the other hand, the essential oils from noni and lemon grass caused phytotoxicity when applied to seedlings at concentrations of 2000 and 1500 μL L-1, respectively. The major constituents found in lemon grass essential oil were Geranial and Neral, while Octanoic Acid was found in noni oil. Lower values in the area below the rust progress curve were observed with the preventive application of lemon grass and noni essential oils.

  16. 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.

  17. Barley Stem Rust Resistance Genes: Structure and Function

    Directory of Open Access Journals (Sweden)

    Andris Kleinhofs

    2009-07-01

    Full Text Available Rusts are biotrophic pathogens that attack many plant species but are particularly destructive on cereal crops. The stem rusts (caused by have historically caused severe crop losses and continue to threaten production today. Barley ( L. breeders have controlled major stem rust epidemics since the 1940s with a single durable resistance gene . As new epidemics have threatened, additional resistance genes were identified to counter new rust races, such as the complex locus against races QCCJ and TTKSK. To understand how these genes work, we initiated research to clone and characterize them. The gene encodes a unique protein kinase with dual kinase domains, an active kinase, and a pseudokinase. Function of both domains is essential to confer resistance. The and genes are closely linked and function coordinately to confer resistance to several wheat ( L. stem rust races, including the race TTKSK (also called Ug99 that threatens the world's barley and wheat crops. The gene encodes typical resistance gene domains NBS, LRR, and protein kinase but is unique in that all three domains reside in a single gene, a previously unknown structure among plant disease resistance genes. The gene encodes an actin depolymerizing factor that functions in cytoskeleton rearrangement.

  18. Protecting steel from rusting by rust. The mechanism of rust formation and its control

    International Nuclear Information System (INIS)

    Kimura, Masao

    2008-01-01

    Weathering steel, when exposed outdoors for a few years, forms a protective layer resulting in reduction of the corrosion rate. The state of rusts is fundamental for understanding its mechanisms, but the structure and its relationship with the mechanism have not been understood. In this study, a new crystallographic approach was applied to reveal nano-structure of rusts with using of X-ray synchrotron radiation. It has been shown that additional elements alter the corrosion process in its early stage, resulting in formation of protective rusts. (author)

  19. 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...

  20. 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.

  1. Genome-Wide Association Mapping of Crown Rust Resistance in Oat Elite Germplasm.

    Science.gov (United States)

    Klos, Kathy Esvelt; Yimer, Belayneh A; Babiker, Ebrahiem M; Beattie, Aaron D; Bonman, J Michael; Carson, Martin L; Chong, James; Harrison, Stephen A; Ibrahim, Amir M H; Kolb, Frederic L; McCartney, Curt A; McMullen, Michael; Fetch, Jennifer Mitchell; Mohammadi, Mohsen; Murphy, J Paul; Tinker, Nicholas A

    2017-07-01

    Oat crown rust, caused by f. sp. , is a major constraint to oat ( L.) production in many parts of the world. In this first comprehensive multienvironment genome-wide association map of oat crown rust, we used 2972 single-nucleotide polymorphisms (SNPs) genotyped on 631 oat lines for association mapping of quantitative trait loci (QTL). Seedling reaction to crown rust in these lines was assessed as infection type (IT) with each of 10 crown rust isolates. Adult plant reaction was assessed in the field in a total of 10 location-years as percentage severity (SV) and as infection reaction (IR) in a 0-to-1 scale. Overall, 29 SNPs on 12 linkage groups were predictive of crown rust reaction in at least one experiment at a genome-wide level of statistical significance. The QTL identified here include those in regions previously shown to be linked with seedling resistance genes , , , , , and and also with adult-plant resistance and adaptation-related QTL. In addition, QTL on linkage groups Mrg03, Mrg08, and Mrg23 were identified in regions not previously associated with crown rust resistance. Evaluation of marker genotypes in a set of crown rust differential lines supported as the identity of . The SNPs with rare alleles associated with lower disease scores may be suitable for use in marker-assisted selection of oat lines for crown rust resistance. Copyright © 2017 Crop Science Society of America.

  2. Genome-wide association study of rust traits in orchardgrass using SLAF-seq technology.

    Science.gov (United States)

    Zeng, Bing; Yan, Haidong; Liu, Xinchun; Zang, Wenjing; Zhang, Ailing; Zhou, Sifan; Huang, Linkai; Liu, Jinping

    2017-01-01

    While orchardgrass ( Dactylis glomerata L.) is a well-known perennial forage species, rust diseases cause serious reductions in the yield and quality of orchardgrass; however, genetic mechanisms of rust resistance are not well understood in orchardgrass. In this study, a genome-wide association study (GWAS) was performed using specific-locus amplified fragment sequencing (SLAF-seq) technology in orchardgrass. A total of 2,334,889 SLAF tags were generated to produce 2,309,777 SNPs. ADMIXTURE analysis revealed unstructured subpopulations for 33 accessions, indicating that this orchardgrass population could be used for association analysis. Linkage disequilibrium (LD) analysis revealed an average r 2 of 0.4 across all SNP pairs, indicating a high extent of LD in these samples. Through GWAS, a total of 4,604 SNPs were found to be significantly ( P  rust trait. The bulk analysis discovered a number of 5,211 SNPs related to rust trait. Two candidate genes, including cytochrome P450, and prolamin were implicated in disease resistance through prediction of functional genes surrounding each high-quality SNP ( P  rust traits based on GWAS analysis and bulk analysis. The large number of SNPs associated with rust traits and these two candidate genes may provide the basis for further research on rust resistance mechanisms and marker-assisted selection (MAS) for rust-resistant lineages.

  3. The Stripe State in Cupratesa

    Directory of Open Access Journals (Sweden)

    Lee T.-K.

    2012-03-01

    Full Text Available Since the discovery of high temperature superconductors (HTS two decades ago, many anomalous properties have been reported. One of the most interesting properties is the possible existence of the stripe state consisting of one dimensional charge-density modulation coupled with some kind of spin ordering. X-ray and neutron scattering experiments and recently high resolution scanning tunneling microscopy have reported direct evidences of such a structure. In particular it has found in the La-Sr-Cu-O (LSCO family the existence of the half-doped stripe with average of half a hole in one charge modulation period below and about 1/8 hole density. These results have fueled the idea about the presence of these charge or spin density wave states competing with the superconducting phase in underdoped HTS. They may even contribute to the pairing mechanism. In this talk, we will demonstrate that the presence of these stripes is actually a natural consequence of the strongly interacting t-J model by using a variational approach which provides a good enough accuracy to address the subtle result. Furthermore we show that half-doped stripes could be stabilized in hole-doped systems if we assume a simple electron-phonon interaction to renormalize the electron mass. However we have not found any evidence to support half-doped stripes in electron-doped systems.

  4. 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

  5. Fighting Asian soybean rust

    Directory of Open Access Journals (Sweden)

    Caspar eLangenbach

    2016-06-01

    Full Text Available Phakopsora pachyrhizi is a biotrophic fungus provoking Asian soybean rust (SBR disease. SBR poses a major threat to global soybean production. Though several resistance genes provided soybean immunity to certain P. pachyrhizi races, the pathogen swiftly overcame this resistance. Therefore, fungicides are the only current means to control SBR. However, insensitivity to fungicides is soaring in P. pachyrhizi and, therefore, alternative measures are needed for SBR control. In this article, we discuss the different approaches for fighting SBR and their potential, disadvantages, and advantages over other measures. These encompass conventional breeding for SBR resistance, transgenic approaches, exploitation of transcription factors, secondary metabolites, and antimicrobial peptides, RNAi/HIGS, and biocontrol strategies. It seems that an integrating approach exploiting different measures is likely to provide the best possible means for the effective control of SBR.

  6. 75 FR 44881 - Black Stem Rust; Additions of Rust-Resistant Varieties

    Science.gov (United States)

    2010-07-30

    ...-0035] Black Stem Rust; Additions of Rust-Resistant Varieties AGENCY: Animal and Plant Health Inspection... direct final rule notified the public of our intention to amend the black stem rust quarantine and regulations by adding 21 varieties to the list of rust-resistant Berberis species or cultivars and 2 varieties...

  7. 76 FR 3011 - Black Stem Rust; Additions of Rust-Resistant Varieties

    Science.gov (United States)

    2011-01-19

    ...-0088] Black Stem Rust; Additions of Rust-Resistant Varieties AGENCY: Animal and Plant Health Inspection... notified the public of our intention to amend the black stem rust quarantine and regulations by adding four varieties to the list of rust-resistant Berberis species or cultivars. We did not receive any written...

  8. 75 FR 54461 - Black Stem Rust; Additions of Rust-Resistant Varieties

    Science.gov (United States)

    2010-09-08

    .... APHIS-2010-0088] Black Stem Rust; Additions of Rust-Resistant Varieties AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Direct final rule. SUMMARY: We are amending the black stem rust quarantine and regulations by adding four varieties to the list of rust-resistant Berberis species or cultivars...

  9. Improving striping operations through system optimization.

    Science.gov (United States)

    2015-09-01

    Striping operations generate a significant workload for Missouri Department of Transportation (MoDOT) maintenance : operations. The requirement for each striping crew to replenish its stock of paint and other consumable items from a bulk storage : fa...

  10. Coffee Leaf Rust Epidemics ( Hemileia vastatrix ) in Montane Coffee ...

    African Journals Online (AJOL)

    Besides drastic reduction in the forest cover and low average yield, the crop is attacked by several diseases among which coffee berry disease, coffee wilt disease and coffee leaf rust caused by Colletotrichum kahawae, Gibberella xylarioides and Hemileia vastatrix, respectively, are the major fungal diseases contributing to ...

  11. White pine blister rust resistance research in Minnesota and Wisconsin

    Science.gov (United States)

    Andrew David; Paul Berrang; Carrie Pike

    2012-01-01

    The exotic fungus Cronartium ribicola causes the disease white pine blister rust on five-needled pines throughout North America. Although the effects of this disease are perhaps better known on pines in the western portion of the continent, the disease has also impacted regeneration and growth of eastern white pine (Pinus strobus L. ...

  12. Sources of stem rust resistance in Ethiopian tetraploid wheat ...

    African Journals Online (AJOL)

    Stem or black rust of wheat caused by the fungus Puccinia graminis f. sp. tritici Ericks and Henn (Pgt) is an important disease on wheat worldwide. Pgt is an obligate biotroph, heteroceous in its life cycle and heterothallic in mating type. Seedlings of 41 emmer (Triticum dicoccum), 56 durum (T. durum) wheat accessions were ...

  13. White pine blister rust in the interior Mountain West

    Science.gov (United States)

    Kelly Burns; Jim Blodgett; Dave Conklin; Brian Geils; Jim Hoffman; Marcus Jackson; William Jacobi; Holly Kearns; Anna Schoettle

    2010-01-01

    White pine blister rust is an exotic, invasive disease of white, stone, and foxtail pines (also referred to as white pines or five-needle pines) in the genus Pinus and subgenus Strobus (Price and others 1998). Cronartium ribicola, the fungus that causes WPBR, requires an alternate host - currants and gooseberries in the genus Ribes and species of Pedicularis...

  14. Developing clones of Eucalyptus cloeziana resistant to rust (Puccinia psidii)

    Science.gov (United States)

    Rafael F. Alfenas; Marcelo M. Coutinho; Camila S. Freitas; Rodrigo G. Freitas; Acelino C. Alfenas

    2012-01-01

    Besides its high resistance to Chrysoporthe cubensis canker, Eucalyptus cloeziana F. Muell. is a highly valuable tree species for wood production. It can be used for furniture, electric poles, fence posts, and charcoal. Nevertheless, it is highly susceptible to the rust caused by Puccinia psidii, which...

  15. Comparisons of visual rust assessments and DNA levels of Phakopsora pachyrhizi in soybean genotypes varying in rust resistance

    Science.gov (United States)

    Soybean resistance to Phakopsora pachyrhizi, the cause of soybean rust, has been characterized by the following three infection types (i) immune response (IM; complete resistance) with no visible lesions, (ii) resistant reaction with reddish brown (RB) lesions (incomplete resistance), and (iii) susc...

  16. Monitoring quantity and quality of striped catfish pond effluent

    NARCIS (Netherlands)

    Heijden, van der P.G.M.; Poelman, M.; Bosma, R.H.; Long, N.; Son, V.M.

    2012-01-01

    The production of striped catfish and other fish species in ponds has several possible impacts on the environment, one of which is caused by the discharge of pond waste water (effluent), which is enriched with nitrogen and phosphorous compounds as result of feeding and fish faeces. To restrict the

  17. Bi-sensory, striped representations: comparative insights from owl and platypus.

    Science.gov (United States)

    Pettigrew, John D

    2004-01-01

    Bi-sensory striped arrays are described in owl and platypus that share some similarities with the other variant of bi-sensory striped array found in primate and carnivore striate cortex: ocular dominance columns. Like ocular dominance columns, the owl and platypus striped systems each involve two different topographic arrays that are cut into parallel stripes, and interdigitated, so that higher-order neurons can integrate across both arrays. Unlike ocular dominance stripes, which have a separate array for each eye, the striped array in the middle third of the owl tectum has a separate array for each cerebral hemisphere. Binocular neurons send outputs from both hemispheres to the striped array where they are segregated into parallel stripes according to hemisphere of origin. In platypus primary somatosensory cortex (S1), the two arrays of interdigitated stripes are derived from separate sensory systems in the bill, 40,000 electroreceptors and 60,000 mechanoreceptors. The stripes in platypus S1 cortex produce bimodal electrosensory-mechanosensory neurons with specificity for the time-of-arrival difference between the two systems. This "thunder-and-lightning" system would allow the platypus to estimate the distance of the prey using time disparities generated at the bill between the earlier electrical wave and the later mechanical wave caused by the motion of benthic prey. The functional significance of parallel, striped arrays is not clear, even for the highly-studied ocular dominance system, but a general strategy is proposed here that is based on the detection of temporal disparities between the two arrays that can be used to estimate distance.

  18. Frequency and distribution of the brown rust resistance gene Bru1 and implications for the Louisiana sugarcane breeding programme

    Science.gov (United States)

    Brown rust, caused by the fungus Puccinia melanocephala, is an important disease of sugarcane posing an increasing threat to sugarcane industries worldwide. A major gene, Bru1, has been shown to contribute a significant proportion of brown rust resistance in multiple sugarcane industries. The recent...

  19. Identification of nine pathotype-specific genes conferring resistance to fusiform rust in loblolly pine (Pinus taeda L.)

    Science.gov (United States)

    Henry Amerson; C. Dana Nelson; Thomas L. Kubisiak; E.George Kuhlman; Saul Garcia

    2015-01-01

    Nearly two decades of research on the host-pathogen interaction in fusiform rust of loblolly pine is detailed. Results clearly indicate that pathotype-specific genes in the host interacting with pathogen avirulence cause resistance as defined by the non-gall phenotype under favorable environmental conditions for disease development. In particular, nine fusiform rust...

  20. White pine blister rust in high-elevation white pines: Screening for simply-inherited, hypersensitive resistance

    Science.gov (United States)

    Detlev R. Vogler; Annette Delfino-Mix; Anna W. Schoettle

    2006-01-01

    Recent concern about survival and recovery of high-elevation white pine ecosystems has returned white pine blister rust (caused by Cronartiurn ribicola) to prominence as a significant threat to forest health in the western U.S. (Sainman et al., 2003). This, in turn, has spurred new research into potential rust-resistance mechanisms in high-elevation...

  1. Discovery of a novel stem rust resistance allele in durum wheat that exhibits differential reactions to Ug99 isolates

    Science.gov (United States)

    Wheat stem rust, caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn, can incur yield losses on susceptible cultivars of durum wheat, Triticum turgidum ssp. durum (Desf.) Husnot. Though several durum cultivars possess the stem rust resistance gene Sr13, additional genes in durum wheat effec...

  2. Distribution and frequency of Bru1, a major brown rust resistance gene, in the sugarcane world collection

    Science.gov (United States)

    Brown rust, caused by Puccinia melanocephala, is an important disease of sugarcane worldwide. Molecular markers for a major brown rust resistance gene, Bru1, were used to screen a total of 1,282 clones in the World Collection of Sugarcane and Related Grasses (WCSRG) to determine the distribution and...

  3. Genetic mapping of stem rust resistance to Puccinia graminis f. sp. tritici race TRTTF in the Canadian wheat cultivar 'Harvest'

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn.(Pgt), is a destructive disease of wheat that can be controlled by deploying effective stem rust resistance (Sr) genes. Highly virulent races of Pgt in Africa have been detected and characterized. These include race T...

  4. 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...

  5. Validação de escala diagramática para estimativa de desfolha provocada pela ferrugemasiática em soja Validation of diagrammatic scale for estimating defoliation caused by the Asian rust in soybeans

    Directory of Open Access Journals (Sweden)

    Mario Hirano

    2010-09-01

    Full Text Available Este estudo teve como objetivo avaliar a precisão e acurácia de avaliadores com o uso de escala diagramática, em estimativas de desfolha provocada por doenças em soja. A escala apresenta seis níveis de severidade de desfolha (5, 15, 45, 65, 85 e 100%. As imagens utilizadas para avaliação foram obtidas em parcelas atacadas por ferrugem asiática (Phakopsora pachyrhizi, apresentando diferentes níveis de desfolha. A validação foi feita por dez avaliadores, utilizando-se como parâmetro de comparação dados reais da área com cobertura foliar, obtidos através de processamento de imagens, nos softwares Paint Shop Pro 4, e Adobe Photoshop 7.0. Quando não foi utilizada a escala, os avaliadores apresentaram tendência de subestimar a severidade de desfolha nos níveis mais baixos e de superestimar em níveis altos. A acurácia e precisão dos avaliadores aumentaram com o auxílio da escala diagramática.This study aimed to evaluate the precision and accuracy of evaluators using diagrammatic scale to estimate defoliation caused by diseases in soybean. The scale had six levels of severity of defoliation (5, 15, 45, 65, 85 and 100%. The images used for evaluation were obtained in plots attacked by Asian soybean rust (Phakopsora pachyrhizi, presenting different levels of defoliation. The validation was performed by ten evaluators, comparing estimated data with the actual data of the area coverage leaf, obtained by processing images in Paint Shop Pro 4 software, and Adobe Photoshop 7.0. The evaluators presented tendency to underestimate the defoliation in the lower levels of severity and overestimate the defoliation in high levels of severity, when the scale was not used. The accuracy and precision of the evaluators increased with the use of the scale diagrammatic.

  6. 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.

  7. 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.

  8. A consensus map for Ug99 stem rust resistance loci in wheat.

    Science.gov (United States)

    Yu, Long-Xi; Barbier, Hugues; Rouse, Matthew N; Singh, Sukhwinder; Singh, Ravi P; Bhavani, Sridhar; Huerta-Espino, Julio; Sorrells, Mark E

    2014-07-01

    This consensus map of stem rust genes, QTLs, and molecular markers will facilitate the identification of new resistance genes and provide a resource of in formation for development of new markers for breeding wheat varieties resistant to Ug99. The global effort to identify new sources of resistance to wheat stem rust, caused by Puccinia graminis f. sp. tritici race group Ug99 has resulted in numerous studies reporting both qualitative genes and quantitative trait loci. The purpose of our study was to assemble all available information on loci associated with stem rust resistance from 21 recent studies on Triticum aestivum L. (bread wheat) and Triticum turgidum subsp. durum desf. (durum wheat). The software LPmerge was used to construct a stem rust resistance loci consensus wheat map with 1,433 markers incorporating Single Nucleotide Polymorphism, Diversity Arrays Technology, Genotyping-by-Sequencing as well as Simple Sequence Repeat marker information. Most of the markers associated with stem rust resistance have been identified in more than one population. Several loci identified in these populations map to the same regions with known Sr genes including Sr2, SrND643, Sr25 and Sr57 (Lr34/Yr18/Pm38), while other significant markers were located in chromosome regions where no Sr genes have been previously reported. This consensus map provides a comprehensive source of information on 141 stem rust resistance loci conferring resistance to stem rust Ug99 as well as linked markers for use in marker-assisted selection.

  9. 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.

  10. Characterization of Brachypodium distachyon as a nonhost model against switchgrass rust pathogen Puccinia emaculata.

    Science.gov (United States)

    Gill, Upinder S; Uppalapati, Srinivasa R; Nakashima, Jin; Mysore, Kirankumar S

    2015-05-08

    Switchgrass rust, caused by Puccinia emaculata, is an important disease of switchgrass, a potential biofuel crop in the United States. In severe cases, switchgrass rust has the potential to significantly affect biomass yield. In an effort to identify novel sources of resistance against switchgrass rust, we explored nonhost resistance against P. emaculata by characterizing its interactions with six monocot nonhost plant species. We also studied the genetic variations for resistance among Brachypodium inbred accessions and the involvement of various defense pathways in nonhost resistance of Brachypodium. We characterized P. emaculata interactions with six monocot nonhost species and identified Brachypodium distachyon (Bd21) as a suitable nonhost model to study switchgrass rust. Interestingly, screening of Brachypodium accessions identified natural variations in resistance to switchgrass rust. Brachypodium inbred accessions Bd3-1 and Bd30-1 were identified as most and least resistant to switchgrass rust, respectively, when compared to tested accessions. Transcript profiling of defense-related genes indicated that the genes which were induced in Bd21after P. emaculata inoculation also had higher basal transcript abundance in Bd3-1 when compared to Bd30-1 and Bd21 indicating their potential involvement in nonhost resistance against switchgrass rust. In the present study, we identified Brachypodium as a suitable nonhost model to study switchgrass rust which exhibit type I nonhost resistance. Variations in resistance response were also observed among tested Brachypodium accessions. Brachypodium nonhost resistance against P. emaculata may involve various defense pathways as indicated by transcript profiling of defense related genes. Overall, this study provides a new avenue to utilize novel sources of nonhost resistance in Brachypodium against switchgrass rust.

  11. 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.

  12. 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...

  13. 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.

  14. Genotype-by-sequencing facilitates genetic mapping of a stem rust resistance locus in Aegilops umbellulata, a wild relative of cultivated wheat

    OpenAIRE

    Edae, Erena A.; Olivera, Pablo D.; Jin, Yue; Poland, Jesse A.; Rouse, Matthew N.

    2016-01-01

    Background Wild relatives of wheat play a significant role in wheat improvement as a source of genetic diversity. Stem rust disease of wheat causes significant yield losses at the global level and stem rust pathogen race TTKSK (Ug99) is virulent to most previously deployed resistance genes. Therefore, the objective of this study was to identify loci conferring resistance to stem rust pathogen races including Ug99 in an Aegilops umbelluata bi-parental mapping population using genotype-by-seque...

  15. Characterization of mild steel pre rusted and rust converted surfaces through advanced electrochemical analysis

    International Nuclear Information System (INIS)

    Riaz, F.; Rizvi, Z.H.; Arshad, K.

    2008-01-01

    The present work evaluates the anti corrosive properties of a tannin based rust converter applied on the pre rusted steel coupons as compared with the grit blasted bare metal and pre rusted steel coupons. The mechanism and the corrosion control behaviour of the rust converter are characterized and monitored using EIS technique. The result suggested that when the tannin based rust converter applied on the pre rusted/corroded coupon, the protection properties of the mild steel coupon clearly improved because of the more compact conversion layer being formed on the coupon. It is inferred that the rust converter can be applied on the pre rusted samples as an alternative technique to the surface preparation for protection purpose. (author)

  16. A dynamic, web-based resource to identify rust fungi (Pucciniales in southern Africa

    Directory of Open Access Journals (Sweden)

    Alistair R. McTaggart

    2017-09-01

    Full Text Available Rust fungi (Pucciniales are some of the most important plant pathogens that cause diseases of agricultural and tree crops. There are approximately 8,000 described species worldwide. The rust fungi of South Africa were extensively studied by Ethel M. Doidge (1887 – 1965, who listed 468 species. Many nomenclatural and taxonomic changes, together with the discovery of new species and incursions of exotic species, have subsequently outdated Doidge’s monograph. To address this problem, we have developed an interactive Lucid key for the identification of 50 species of rust fungi in 17 genera from countries in southern Africa. The key is dynamic and may be updated in real-time. The Lucid key provides a platform to progressively provide descriptions and images for all rust fungi in southern Africa. Plant pathologists and mycologists are invited to participate in the development of this resource.

  17. Durable resistance to wheat stem rust needed.

    Science.gov (United States)

    Ayliffe, Michael; Singh, Ravi; Lagudah, Evans

    2008-04-01

    The recent outbreak of a new wheat stem rust race capable of parasitizing many commercial wheat cultivars highlights the need for durable disease resistance in crop plants. More advanced breeding approaches using quantitative disease resistance genes and resistance gene pyramids are being used to combat wheat stem rust and other diseases, though widespread adoption of these breeding methodologies is needed to maintain resistance efficacy. Advances in understanding the molecular basis of plant disease resistance at both host and nonhost levels offers further possibilities for stem rust resistance using biotechnological approaches. However, truly durable resistance to wheat stem rust and other phytopathogens seems an unlikely prospect in the face of continually evolving pathogen populations.

  18. Using hierarchical clustering of secreted protein families to classify and rank candidate effectors of rust fungi.

    Science.gov (United States)

    Saunders, Diane G O; Win, Joe; Cano, Liliana M; Szabo, Les J; Kamoun, Sophien; Raffaele, Sylvain

    2012-01-01

    Rust fungi are obligate biotrophic pathogens that cause considerable damage on crop plants. Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, and Melampsora larici-populina, the poplar leaf rust pathogen, have strong deleterious impacts on wheat and poplar wood production, respectively. Filamentous pathogens such as rust fungi secrete molecules called disease effectors that act as modulators of host cell physiology and can suppress or trigger host immunity. Current knowledge on effectors from other filamentous plant pathogens can be exploited for the characterisation of effectors in the genome of recently sequenced rust fungi. We designed a comprehensive in silico analysis pipeline to identify the putative effector repertoire from the genome of two plant pathogenic rust fungi. The pipeline is based on the observation that known effector proteins from filamentous pathogens have at least one of the following properties: (i) contain a secretion signal, (ii) are encoded by in planta induced genes, (iii) have similarity to haustorial proteins, (iv) are small and cysteine rich, (v) contain a known effector motif or a nuclear localization signal, (vi) are encoded by genes with long intergenic regions, (vii) contain internal repeats, and (viii) do not contain PFAM domains, except those associated with pathogenicity. We used Markov clustering and hierarchical clustering to classify protein families of rust pathogens and rank them according to their likelihood of being effectors. Using this approach, we identified eight families of candidate effectors that we consider of high value for functional characterization. This study revealed a diverse set of candidate effectors, including families of haustorial expressed secreted proteins and small cysteine-rich proteins. This comprehensive classification of candidate effectors from these devastating rust pathogens is an initial step towards probing plant germplasm for novel resistance components.

  19. Using hierarchical clustering of secreted protein families to classify and rank candidate effectors of rust fungi.

    Directory of Open Access Journals (Sweden)

    Diane G O Saunders

    Full Text Available Rust fungi are obligate biotrophic pathogens that cause considerable damage on crop plants. Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, and Melampsora larici-populina, the poplar leaf rust pathogen, have strong deleterious impacts on wheat and poplar wood production, respectively. Filamentous pathogens such as rust fungi secrete molecules called disease effectors that act as modulators of host cell physiology and can suppress or trigger host immunity. Current knowledge on effectors from other filamentous plant pathogens can be exploited for the characterisation of effectors in the genome of recently sequenced rust fungi. We designed a comprehensive in silico analysis pipeline to identify the putative effector repertoire from the genome of two plant pathogenic rust fungi. The pipeline is based on the observation that known effector proteins from filamentous pathogens have at least one of the following properties: (i contain a secretion signal, (ii are encoded by in planta induced genes, (iii have similarity to haustorial proteins, (iv are small and cysteine rich, (v contain a known effector motif or a nuclear localization signal, (vi are encoded by genes with long intergenic regions, (vii contain internal repeats, and (viii do not contain PFAM domains, except those associated with pathogenicity. We used Markov clustering and hierarchical clustering to classify protein families of rust pathogens and rank them according to their likelihood of being effectors. Using this approach, we identified eight families of candidate effectors that we consider of high value for functional characterization. This study revealed a diverse set of candidate effectors, including families of haustorial expressed secreted proteins and small cysteine-rich proteins. This comprehensive classification of candidate effectors from these devastating rust pathogens is an initial step towards probing plant germplasm for novel resistance components.

  20. Using Hierarchical Clustering of Secreted Protein Families to Classify and Rank Candidate Effectors of Rust Fungi

    Science.gov (United States)

    Saunders, Diane G. O.; Win, Joe; Cano, Liliana M.; Szabo, Les J.; Kamoun, Sophien; Raffaele, Sylvain

    2012-01-01

    Rust fungi are obligate biotrophic pathogens that cause considerable damage on crop plants. Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, and Melampsora larici-populina, the poplar leaf rust pathogen, have strong deleterious impacts on wheat and poplar wood production, respectively. Filamentous pathogens such as rust fungi secrete molecules called disease effectors that act as modulators of host cell physiology and can suppress or trigger host immunity. Current knowledge on effectors from other filamentous plant pathogens can be exploited for the characterisation of effectors in the genome of recently sequenced rust fungi. We designed a comprehensive in silico analysis pipeline to identify the putative effector repertoire from the genome of two plant pathogenic rust fungi. The pipeline is based on the observation that known effector proteins from filamentous pathogens have at least one of the following properties: (i) contain a secretion signal, (ii) are encoded by in planta induced genes, (iii) have similarity to haustorial proteins, (iv) are small and cysteine rich, (v) contain a known effector motif or a nuclear localization signal, (vi) are encoded by genes with long intergenic regions, (vii) contain internal repeats, and (viii) do not contain PFAM domains, except those associated with pathogenicity. We used Markov clustering and hierarchical clustering to classify protein families of rust pathogens and rank them according to their likelihood of being effectors. Using this approach, we identified eight families of candidate effectors that we consider of high value for functional characterization. This study revealed a diverse set of candidate effectors, including families of haustorial expressed secreted proteins and small cysteine-rich proteins. This comprehensive classification of candidate effectors from these devastating rust pathogens is an initial step towards probing plant germplasm for novel resistance components. PMID:22238666

  1. Strategies for improving rust resistance in oats

    International Nuclear Information System (INIS)

    Harder, D.E.; McKenzie, R.I.H.; Martens, J.W.; Brown, P.D.

    1977-01-01

    During the history of breeding oats for rust resistance in Canada the known sources of resistance proved inadequate to counter the virulence potential of both stem rust (Puccinia graminis avenae) and crown rust (P. coronata avenae). A major programme to overcome the rust problem was undertaken at Winnipeg, involving four alternate approaches: (1) A search for new resistance in wild oat species, particularly Avena sterilis, has provided a wealth of good resistance to crown rust, but less to stem rust. Much of the A. sterilis-derived crown rust resistance is now being used world-wide; (2) Efforts at synthesizing new resistance by mutation breeding methods have not been successful. Of about seven million plants examined, only one showed significant new resistance, but this was associated with poor plant type; (3) Resistance with low levels of expression but which appears broadly effective has been observed against both stem and crown rusts. It appears that numbers of these low-level genes exist, and that they can be accumulated to provide increasingly effective resistance. Problems in using this type of resistance in a practical way are discussed; (4) Excellent rust resistance has been found in lower ploidy species such as A. barbata, but it was not previously possible to stabilize this resistance in hexaploid species. By using mutagenic treatments attempts have been made to translocate smaller portions of the A. barbata chromosome carrying the resistance to the hexaploid cultivar Rodney. In conclusion, mutation breeding methods at present appear to have limited application in synthesizing new rust-resistant genotypes in oats. The search for already existing genetic resistance and its synthesis into multi-genic resistant lines appears to be the most effective way at present of resolving the rust problem in oats. (author)

  2. Disruption of Rpp1-mediated soybean rust immunity by virus-induced gene silencing

    Science.gov (United States)

    Cooper, Bret; Campbell, Kimberly B; McMahon, Michael B; Luster, Douglas G

    2013-01-01

    Phakopsora pachyrhizi, a fungus that causes rust disease on soybean, has potential to impart significant yield loss and disrupt food security and animal feed production. Rpp1 is a soybean gene that confers immunity to soybean rust, and it is important to understand how it regulates the soybean defense system and to use this knowledge to protect commercial crops. It was previously discovered that some soybean proteins resembling transcription factors accumulate in the nucleus of Rpp1 soybeans. To determine if they contribute to immunity, Bean pod mottle virus was used to attenuate or silence the expression of their genes. Rpp1 plants subjected to virus-induced gene silencing exhibited reduced amounts of RNA for 5 of the tested genes, and the plants developed rust-like symptoms after subsequent inoculation with fungal spores. Symptoms were associated with the accumulation of rust fungal RNA and protein. Silenced plants also had reduced amounts of RNA for the soybean Myb84 transcription factor and soybean isoflavone O-methyltransferase, both of which are important to phenylpropanoid biosynthesis and lignin formation, crucial components of rust resistance. These results help resolve some of the genes that contribute to Rpp1-mediated immunity and improve upon the knowledge of the soybean defense system. It is possible that these genes could be manipulated to enhance rust resistance in otherwise susceptible soybean cultivars. PMID:24401541

  3. Molecular mapping of a sunflower rust resistance gene from HAR6.

    Science.gov (United States)

    Bulos, Mariano; Ramos, María L; Altieri, Emiliano; Sala, Carlos A

    2013-03-01

    Sunflower rust, caused by Puccinia helianthi Schw., can result in significant yield losses in cultivated sunflower (Helianthus annuus L. var. macrocarpus Ckll.). HAR6 is a germplasm population resistant to most predominant rust races. The objectives of this study were to map the resistance factor present in HAR6 (R HAR6 ), and to provide and validate molecular tools for the identification of this gene for marker assisted selection purposes. Virulence reaction of seedlings for the F2 population and F2:3 families suggested that a single dominant gene confers rust resistance in HAR6-1, a selected rust resistance line from the original population. Genetic mapping with eight markers covered 97.4 cM of genetic distance on linkage group 13 of the sunflower consensus map. A co-dominant marker ZVG61 is the closest marker distal to R HAR6 at a genetic distance of 0.7 cM, while ORS581, a dominant marker linked in the coupling phase, is proximal to R HAR6 at a genetic distance of 1.5 cM. Validation of these markers was assessed by converting a susceptible line into a rust resistant isoline by means of marker assisted backcrossing. The application of these results to assist the breeding process and to design new strategies for rust control in sunflower is discussed.

  4. Disruption of Rpp1-mediated soybean rust immunity by virus-induced gene silencing.

    Science.gov (United States)

    Cooper, Bret; Campbell, Kimberly B; McMahon, Michael B; Luster, Douglas G

    2013-01-01

    Phakopsora pachyrhizi, a fungus that causes rust disease on soybean, has potential to impart significant yield loss and disrupt food security and animal feed production. Rpp1 is a soybean gene that confers immunity to soybean rust, and it is important to understand how it regulates the soybean defense system and to use this knowledge to protect commercial crops. It was previously discovered that some soybean proteins resembling transcription factors accumulate in the nucleus of Rpp1 soybeans. To determine if they contribute to immunity, Bean pod mottle virus was used to attenuate or silence the expression of their genes. Rpp1 plants subjected to virus-induced gene silencing exhibited reduced amounts of RNA for 5 of the tested genes, and the plants developed rust-like symptoms after subsequent inoculation with fungal spores. Symptoms were associated with the accumulation of rust fungal RNA and protein. Silenced plants also had reduced amounts of RNA for the soybean Myb84 transcription factor and soybean isoflavone O-methyltransferase, both of which are important to phenylpropanoid biosynthesis and lignin formation, crucial components of rust resistance. These results help resolve some of the genes that contribute to Rpp1-mediated immunity and improve upon the knowledge of the soybean defense system. It is possible that these genes could be manipulated to enhance rust resistance in otherwise susceptible soybean cultivars.

  5. Relación entre Incidencia y Severidad de la Roya Asiática de la Soya Causada por Phakopsora pachyrhizi Sydow & Sydow Relationship Between Incidence and Severity of Asian Soybean Rust Caused by Phakopsora pachyrhizi Sydow & Sydow

    Directory of Open Access Journals (Sweden)

    Felipe Rafael Garcés Fiallos

    2011-12-01

    Full Text Available Se relaciona la incidencia con la severidad de la roya asiática de la soya, donde los valores generados por las ecuaciones pueden ser usados en cualquier estudio de este patosistema, proporcionando una herramienta para evaluar la incidencia como también la severidad. Se generaron gradientes de la enfermedad mediante el uso de fungicidas y momentos de aplicación, de manera preventiva y curativa. El experimento de campo con el cultivar Nidera 5909 RG, fue distribuido en bloques completos al azar. La intensidad de la roya asiática fue medida en los estratos inferior, medio y superior de la planta, a través de diferentes conteos de incidencia (porcentaje y severidad (lesiones cm-2, urédias cm-2 y porcentaje en folíolos. Las regresiones realizadas, presentaron una correlación significativa entre incidencia y severidad a 1% de probabilidad. Con los datos obtenidos, el evaluador puede escoger el método de cuantificación mas razonable o confiable a su criterio para otros trabajos de investigación o aplicar un determinado control de la enfermedad, utilizando las ecuaciones lineales generadas, facilitando el trabajo de cuantificar la roya asiática, bien se busque medir la incidencia (% o el número de lesiones cm-2, urédias cm-2 o severidad (%.Incidence is related to severity of the Asian soybean rust, where values generated by the equations can be used in any study of this pathosystem, providing a tool to evaluate incidence as well severity. Gradients of the disease were generated by means of the use of fungicides and moments of application, in a preventive and curative way. The field experiment with the cultivar Nidera RG 5909, was distributed in a randomized complete block. The intensity of Asian rust layers was measured in the lower, middle and top of the plant, through various counts of incidence (percentage and severity (lesions cm-2, uredinia cm-2 and percentage in leaflets. The regressions showed a significant correlation between

  6. Multiple genotypes within aecial clusters in Puccinia graminis and Puccinia coronata: improved understanding of the biology of cereal rust fungi.

    Science.gov (United States)

    Berlin, Anna; Samils, Berit; Andersson, Björn

    2017-01-01

    Cereal rust fungi ( Puccinia spp.) are among the most economically important plant pathogens. These fungi have a complex life cycle, including five spore stages and two hosts. They infect one grass host on which they reproduce clonally and cause the cereal rust diseases, while the alternate host is required for sexual reproduction. Although previous studies clearly demonstrate the importance of the alternate host in creating genetic diversity in cereal rust fungi, little is known about the amount of novel genotypes created in each successful completion of a sexual reproduction event. In this study, single sequence repeat markers were used to study the genotypic diversity within aecial clusters by genotyping individual aecial cups. Two common cereal rusts, Puccinia graminis causing stem rust and Puccinia coronata the causal agent of crown rust were investigated. We showed that under natural conditions, a single aecial cluster usually include several genotypes, either because a single pycnial cluster is fertilized by several different pycniospores, or because aecia within the cluster are derived from more than one fertilized adjoining pycnial cluster, or a combination of both. Our results imply that although sexual events in cereal rust fungi in most regions of the world are relatively rare, the events that occur may still significantly contribute to the genetic variation within the pathogen populations.

  7. Difference between Cr and Ni K-edge XANES spectra of rust layers formed on Fe-based binary alloys exposed to Cl-rich environment

    International Nuclear Information System (INIS)

    Konishi, Hiroyuki; Mizuki, Jun'ichiro; Yamashita, Masato; Uchida, Hitoshi

    2005-01-01

    The rust layer formed on weathering steel possesses a strong protective ability against corrosives in an atmospheres. This ability is related to the structure of the rust layer. The difference in the protective ability of a rust layer. The difference in the protective ability of a rust layer in a Cl-rich environment between conventional weathering steel containing Cr and advanced weathering steel containing Ni is believed to be caused by the differences in local structural and chemical properties between alloying elements. Cr and Ni, in the rust layer. In order to examine the effect of these alloying elements on the structure of the rust layer formed on steel in a Cl-rich environment, we have performed Cr and Ni K-edge X-ray absorption near-edge structure (XANES) measurements for the rust layer of Fe-Cr and Fe-Ni binary alloys exposed to a Cl-rich atmosphere using synchrotron radiation. The results of the Cr K-edge XANES measurements for the rust layer of Fe-Cr binary alloys show that the atomic geometry around Cr depends on the concentration of Cr. Therefore, it is expected that the local structure around Cr in the rust layer is unstable. On the other hand, from the results of the Ni K-edge XANES measurements for the rust layer of Fe-Ni binary alloys. Ni is considered to be positioned at a specific site in the crystal structure of a constituent of the rust layer, such as akaganeite or magnetite. As a consequence, Ni negligibly interacts with Cl - ions in the rust layer. (author)

  8. First report of the white pine blister rust fungus, Cronartium ribicola, infecting Pinus flexilis on Pine Mountain, Humboldt National Forest, Elko County, northeastern Nevada, U.S.A.

    Science.gov (United States)

    Detlev R. Vogler; Patricia E. Maloney; Tom Burt; Jacob W. Snelling

    2017-01-01

    In 2013, while surveying for five-needle white pine cone crops in northeastern Nevada, we observed white pine blister rust, caused by the rust pathogen Cronartium ribicola Fisch., infecting branches and stems of limber pines (Pinus flexilis James) on Pine Mountain (41.76975°N, 115.61622°W), Humboldt National Forest,...

  9. Blister rust resistance among 19 families of whitebark pine, Pinus albicaulis, from Oregon and Washington – early results from an artificial inoculation trial

    Science.gov (United States)

    Angelia Kegley; Richard A. Sniezko; Robert Danchok; Douglas P. Savin

    2012-01-01

    Whitebark pine is considered one of the most susceptible white pine species to white pine blister rust, the disease caused by the non-native pathogen Cronartium ribicola. High mortality from blister rust and other factors in much of the range in the United States and Canada have raised serious concerns about the future viability of this high-...

  10. Historic Rust College: Fulfilling a Mission.

    Science.gov (United States)

    Hoffman, Carl

    1989-01-01

    Describes Rust College, a Mississippi college dedicated to educating Blacks from economically and educationally impoverished backgrounds. Discusses the college's financial management, recent fund-raising efforts, building program, and academic programs. Examines the role of the predominantly Black college and Rust's mission to help students…

  11. Screening oat populations for rust resistant mutants

    International Nuclear Information System (INIS)

    McKenzie, R.I.H.; Martens, J.W.; Harder, D.E.; Brown, P.D.

    1976-01-01

    In 1972 a two million M 2 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 M 2 plants were examined for rust resistance at Morden and 38 were harvested. None of the M 2 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 M 2 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 M 2 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)

  12. Rust-Bio: a fast and safe bioinformatics library

    NARCIS (Netherlands)

    J. Köster (Johannes)

    2015-01-01

    textabstractWe present Rust-Bio, the first general purpose bioinformatics library for the innovative Rust programming language. Rust-Bio leverages the unique combination of speed, memory safety and high-level syntax offered by Rust to provide a fast and safe set of bioinformatics algorithms and data

  13. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    Mona Singh

    2017-12-08

    Dec 8, 2017 ... leaf rust race 77-5 under artificial epiphytotic conditions. NILF3s were tested in two isolated nurseries inoculated with mixture of leaf and stem rust races. The generations raised at Wellington were naturally exposed to leaf and stem rusts, as Wellington is a natural hot spot for the two rusts (Nagarajan et al.

  14. Molecular mapping of stem and leaf rust resistance in wheat.

    Science.gov (United States)

    Khan, R R; Bariana, H S; Dholakia, B B; Naik, S V; Lagu, M D; Rathjen, A J; Bhavani, S; Gupta, V S

    2005-09-01

    Stem rust caused by Puccinia graminis f. sp. tritici Eriks and Henn and leaf rust caused by Puccinia triticina Rob. ex Desm. are major constraints to wheat production worldwide. In the present study, F(4)-derived SSD population, developed from a cross between Australian cultivars 'Schomburgk' and 'Yarralinka', was used to identify molecular markers linked to rust resistance genes Lr 3 a and Sr 22. A total of 1,330 RAPD and 100 ISSR primers and 33 SSR primer pairs selected ob the basis of chromosomal locations of these genes were used. The ISSR marker UBC 840(540) was found to be linked with Lr 3 a in repulsion at a distance of 6.0 cM. Markers cfa 2019 and cfa 2123 flanked Sr 22 at a distance of 5.9 cM (distal) and 6.0 cM (proximal), respectively. The use of these markers in combination would predict the presence or absence of Sr 22 in breeding populations. A previously identified PCR-based diagnostic marker STS 638 linked to Lr 20 was validated in this population. This marker showed a recombination value of 7.1 cM with Lr 20.

  15. Determination of Radiographic Healing: An Assessment of Consistency Using RUST and Modified RUST in Metadiaphyseal Fractures.

    Science.gov (United States)

    Litrenta, Jody; Tornetta, Paul; Mehta, Samir; Jones, Clifford; OʼToole, Robert V; Bhandari, Mohit; Kottmeier, Stephen; Ostrum, Robert; Egol, Kenneth; Ricci, William; Schemitsch, Emil; Horwitz, Daniel

    2015-11-01

    To determine the reliability of the Radiographic Union Scale for Tibia (RUST) score and a new modified RUST score in quantifying healing and to define a value for radiographic union in a large series of metadiaphyseal fractures treated with plates or intramedullary nails. Healing was evaluated using 2 methods: (1) evaluation of interrater agreement in a series of radiographs and (2) analysis of prospectively gathered data from 2 previous large multicenter trials to define thresholds for radiographic union. Part 1: 12 orthopedic trauma surgeons evaluated a series of radiographs of 27 distal femur fractures treated with either plate or retrograde nail fixation at various stages of healing in random order using a modified RUST score. For each radiographic set, the reviewer indicated if the fracture was radiographically healed. Part 2: The radiographic results of 2 multicenter randomized trials comparing plate versus nail fixation of 81 distal femur and 46 proximal tibia fractures were reviewed. Orthopaedic surgeons at 24 trauma centers scored radiographs at 3, 6, and 12 months postoperatively using the modified RUST score above. Additionally, investigators indicated if the fracture was healed or not healed. The intraclass correlation coefficient (ICC) with 95% confidence intervals was determined for each cortex, the standard and modified RUST score, and the assignment of union for part 1 data. The RUST and modified RUST that defined "union" were determined for both parts of the study. ICC: The modified RUST score demonstrated slightly higher ICCs than the standard RUST (0.68 vs. 0.63). Nails had substantial agreement, whereas plates had moderate agreement using both modified and standard RUST (0.74 and 0.67 vs. 0.59 and 0.53). The average standard and modified RUST at union among all fractures was 8.5 and 11.4. Nails had higher standard and modified RUST scores than plates at union. The ICC for union was 0.53 (nails: 0.58; plates: 0.51), which indicates moderate

  16. Bulk temperature measurement in thermally striped pipe flows

    International Nuclear Information System (INIS)

    Lemure, N.; Olvera, J.R.; Ruggles, A.E.

    1995-12-01

    The hot leg flows in some Pressurized Water Reactor (PWR) designs have a temperature distribution across the pipe cross-section. This condition is often referred to as a thermally striped flow. Here, the bulk temperature measurement of pipe flows with thermal striping is explored. An experiment is conducted to examine the feasibility of using temperature measurements on the external surface of the pipe to estimate the bulk temperature of the flow. Simple mixing models are used to characterize the development of the temperature profile in the flow. Simple averaging techniques and Backward Propagating Neural Net are used to predict bulk temperature from the external temperature measurements. Accurate bulk temperatures can be predicted. However, some temperature distributions in the flow effectively mask the bulk temperature from the wall and cause significant error in the bulk temperature predicted using this technique

  17. Study Of Rust Preventive Characteristics Of Rust Preventive Oil From Polarization Curve Measurement

    Directory of Open Access Journals (Sweden)

    Iwashima D.

    2015-06-01

    Full Text Available Fe-Cu-C sintered steels are widely used as powder materials, because of its small volumetric shrinkage. However, Cu, which acts as cathode enhance formation of rust Fe2O3·xH2O during fabrication. To prevent formation of Fe2O3·xH2O rust preventive oils are widely used. High viscosity of those rust preventive oils decrease workability. While, low viscosity degrade rust preventive performance. Therefore, it is necessary to develop new rust preventive oils with contradictory properties of low viscosity and superior rust prevention. In this study, we developed technique to quantitatively evaluate rust prevention ability by measuring polarization curve through thin corrosive solution on Fe-Cu-C sintered steels coated with rust preventive oils. The electrochemical measurements were carried out in corrosive solution of 0.35 mass % NaCl. Using a double capillary was added dropwise to the specimen. From the experimental, it is possible to evaluate the corrosion rate quantitatively in the surface of specimen, which was coated with rust preventive oil through thin corrosive solution. From the measurement results, Corrosion rate is reduced by coating the rust preventive oil. Especially, corrosion rate of the specimen coated with oil that showed best performance indicated 10000 times better than that of without oil ones. Zn addition negative correlation between corrosion rate and period of potential oscillation.

  18. Adult Plant Leaf Rust Resistance Derived from Toropi Wheat is Conditioned by Lr78 and Three Minor QTL.

    Science.gov (United States)

    Kolmer, J A; Bernardo, A; Bai, G; Hayden, M J; Chao, S

    2018-02-01

    Leaf rust caused by Puccinia triticina is an important disease of wheat in many regions worldwide. Durable or long-lasting leaf rust resistance has been difficult to achieve because populations of P. triticina are highly variable for virulence to race-specific resistance genes, and respond to selection by resistance genes in released wheat cultivars. The wheat cultivar Toropi, developed and grown in Brazil, was noted to have long-lasting leaf rust resistance that was effective only in adult plants. The objectives of this study were to determine the chromosome location of the leaf rust resistance genes derived from Toropi in two populations of recombinant inbred lines in a partial Thatcher wheat background. In the first population, a single gene with major effects on chromosome 5DS that mapped 2.2 centimorgans distal to IWA6289, strongly reduced leaf rust severity in all 3 years of field plot tests. This gene for adult plant leaf rust resistance was designated as Lr78. In the second population, quantitative trait loci (QTL) with small effects on chromosomes 1BL, 3BS, and 4BS were found. These QTL expressed inconsistently over 4 years of field plot tests. The adult plant leaf rust resistance derived from Toropi involved a complex combination of QTL with large and small effects.

  19. 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.

  20. Structure of titanium-doped goethite rust

    International Nuclear Information System (INIS)

    Nakayama, Takenori; Ishikawa, Tatsuo; Konno, Toyohiko J.

    2005-01-01

    To investigate the influence of titanium addition on the formation and structure of goethite (α-FeOOH) rust which is one of main corrosion products of weathering steel, the artificially synthesized α-FeOOH rusts were prepared by hydrolysis of aqueous solutions of Fe(III) containing Ti(IV) at different atomic ratios (Ti/Fe) in the range 0-0.1. The obtained rusts particles were observed by TEM. Characterization by XRD, N 2 absorption, Moessbauer spectroscopy was also done. TEM observation revealed that the α-FeOOH rust particle size increased with the increase of Ti/Fe, and that Ti-enriched poorly crystalline particles were formed around the rust particles. XRD confirmed that the crystallite size increased with the increase of Ti/Fe, while the XRD peaks decreased in intensity. Specific surface area obtained by N 2 absorption increased with the increase of Ti/Fe. It is deduced from the obtained results that the addition of Ti(IV) increases the crystallite size of α-FeOOH, and produces double domain particles consisting of the particle core and a porous poorly crystalline shell. It is thought that such unique rust structure produced by titanium addition contributes to the protective properties of rust layer of the weathering steel

  1. 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...

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

    Indian Academy of Sciences (India)

    2014-08-18

    Aug 18, 2014 ... McIntosh R. A., Dubcovsky J., Rogers W. J., Morris C., Appels R. and Xia X. C. 2010 Catalogue of gene symbols for wheat: 2010. Supplement. Annu. Wheat Newslett. 56, 273–282. McIntosh R. A., Yamazaki Y., Dubcovsky J., Rogers J., Morris C.,. Somers D. J. et al. 2008 Catalogue of gene symbols for wheat ...

  3. Genetic analysis and location of gene for resistance to stripe rust in ...

    Indian Academy of Sciences (India)

    2013-08-06

    Aug 6, 2013 ... anchor qualitative characteristics, so the gene can be directly located on the wheat genetic map. Also, the sequences of. SSR primers are open for easy genome research applica- tion and have become second-generation molecular markers. (Gupta et al. 2002), and play an important role in the wheat.

  4. Allelic variation at loci controlling stripe rust resistance in spring wheat

    Indian Academy of Sciences (India)

    2014-08-20

    Aug 20, 2014 ... 1Department of Plant Genomics & Biotechnology, PARC Institute of Advanced Studies in Agriculture, National Agricultural. Research Centre, Islamabad 45500, Pakistan. 2National Institute for Genomics & Advanced Biotechnology, National Agricultural Research Centre,. Park Road, Islamabad 45500, ...

  5. Allelic variation at loci controlling stripe rust resistance in spring wheat

    Indian Academy of Sciences (India)

    ... Studies in Agriculture, National Agricultural Research Centre, Islamabad 45500, Pakistan; National Institute for Genomics & Advanced Biotechnology, National Agricultural Research Centre, Park Road, Islamabad 45500, Pakistan; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, ...

  6. Genetic analysis and location of gene for resistance to stripe rust in ...

    Indian Academy of Sciences (India)

    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 ...

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

    Indian Academy of Sciences (India)

    2014-08-18

    Aug 18, 2014 ... markers.Among them, one STS marker, C51STS-4, was located at a genetic distance of 1.4 cM to YrC51 and was closely ..... 118. Horticulture Australia, Christchurch, New. Zealand. Fu D. L., Cristobal U., Assaf D., Ann B., Lynn E., Chen X. M. et al. 2009 A Kinase-START gene confers temperature dependent.

  8. Allelic variation at loci controlling stripe rust resistance in spring wheat

    Indian Academy of Sciences (India)

    ... National Agricultural Research Centre, Islamabad 45500, Pakistan; National Institute for Genomics & Advanced Biotechnology, National Agricultural Research Centre, Park Road, Islamabad 45500, Pakistan; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada ...

  9. Molecular mapping of stripe rust resistance gene Yr51 in chromosome 4AL of wheat

    Czech Academy of Sciences Publication Activity Database

    Randhawa, M.; Bansal, U.; Valárik, Miroslav; Klocová, Barbora; Doležel, Jaroslav; Bariana, H.

    2014-01-01

    Roč. 127, č. 2 (2014), s. 317-324 ISSN 0040-5752 R&D Projects: GA ČR GAP501/10/1740; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : TRITICUM-AESTIVUM L. * DIVERSITY ARRAYS * MAP Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.790, year: 2014

  10. Evaluation of chemical seed treatments for control of stripe rust in spring wheat, 2012

    Science.gov (United States)

    The study was conducted in a field with Palouse silt loam near Pullman, WA. Fertilizer (Osmocota 14-14-14) was applied at 60 lb/A at the time of cultivation on 8 May 12. A randomized block design was used with four replications for each of the seven treatments and a non-treated control. For each plo...

  11. Evaluation of chemical seed treatments for control of stripe rust in winter wheat, 2012

    Science.gov (United States)

    The study was conducted in a field with Palouse silt loam near Pullman, WA. Fertilizer (Osmocota 14-14-14) was applied at 60 lb/A at the time of cultivation on 20 Oct 11. A randomized block design was used with four replications for each of the seven treatments and a non-treated control. For each pl...

  12. Allelic variation at loci controlling stripe rust resistance in spring wheat

    Indian Academy of Sciences (India)

    2014-08-20

    Aug 20, 2014 ... (2012) for the detection of Yr9 and Sr31 in Pakistani wheat varieties. Similarly, Pretorius et al. (2012) also used iag95 to detect Sr31 in African wheat. These studies indicated the reliability of marker iag95. Although this marker has been proved diagnostic, it can- not be used to differentiate the heterozygotes ...

  13. 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.

  14. Stock characteristics of Hudson River striped bass

    International Nuclear Information System (INIS)

    Hoff, T.B.; McLaren, J.B.; Cooper, J.C.

    1988-01-01

    Striped bass, because of their tremendous popularity both commercially and recreationally, were a principal focus of the Hudson River power plant case. Between 1976 and 1979, over 23,000 age-II and older striped bass were studied as one facet of an extensive research program on the spring population in the Hudson River. Samples were collected from the overwintering as well as the spawning portion of the striped bass population, and included immature as well as mature fish. At least 12 age-groups contributed to spawning each year. Of these 12, age-groups III, IV, and V usually were most abundant, but the percentage of the population represented by any single age-group varied as the result of fluctuations in year-class strength. Males first became sexually mature at age II and females at age IV. Fast-growing individuals within a year class tended to mature earlier. Fecundity increased with the size of fish, reaching an observed maximum of about 3 million eggs per female. Although significant annual variations in maturity and growth were detected for Hudson River striped bass, there was no evidence of a consistent change in either variable that might be associated with increasing power plant operations and a reduction in striped bass abundance. Age at maturity and age structure are the two life history components that differ the most between the Hudson River population and other striped bass populations. 36 refs., 7 tabs

  15. Genome-Wide Association Mapping of Leaf Rust Response in a Durum Wheat Worldwide Germplasm Collection.

    Science.gov (United States)

    Aoun, Meriem; Breiland, Matthew; Kathryn Turner, M; Loladze, Alexander; Chao, Shiaoman; Xu, Steven S; Ammar, Karim; Anderson, James A; Kolmer, James A; Acevedo, Maricelis

    2016-11-01

    Leaf rust (caused by Erikss. []) is increasingly impacting durum wheat ( L. var. ) production with the recent appearance of races with virulence to widely grown cultivars in many durum producing areas worldwide. A highly virulent race on durum wheat was recently detected in Kansas. This race may spread to the northern Great Plains, where most of the US durum wheat is produced. The objective of this study was to identify sources of resistance to several races from the United States and Mexico at seedling stage in the greenhouse and at adult stage in field experiments. Genome-wide association study (GWAS) was used to identify single-nucleotide polymorphism (SNP) markers associated with leaf rust response in a worldwide durum wheat collection of 496 accessions. Thirteen accessions were resistant across all experiments. Association mapping revealed 88 significant SNPs associated with leaf rust response. Of these, 33 SNPs were located on chromosomes 2A and 2B, and 55 SNPs were distributed across all other chromosomes except for 1B and 7B. Twenty markers were associated with leaf rust response at seedling stage, while 68 markers were associated with leaf rust response at adult plant stage. The current study identified a total of 14 previously uncharacterized loci associated with leaf rust response in durum wheat. The discovery of these loci through association mapping (AM) is a significant step in identifying useful sources of resistance that can be used to broaden the relatively narrow leaf rust resistance spectrum in durum wheat germplasm. Copyright © 2016 Crop Science Society of America.

  16. 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.

  17. A genome-wide association study of field and seedling response to stem rust pathogen races reveals combinations of race-specific resistance genes in North American spring wheat

    Science.gov (United States)

    Stem rust of wheat caused by the fungal pathogen Puccinia graminis f. sp. tritici historically caused major yield losses of wheat worldwide. To understand the genetic basis of stem rust resistance in conventional North American spring wheat, genome-wide association analysis (GWAS) was conducted on a...

  18. Molecular and genetic study of wheat rusts

    African Journals Online (AJOL)

    Nicholas Le Maitre

    Phylogenetic trees were created for leaf and stem rust pathotypes. Field isolates of ... Key words: Prevalence, microsatellite, amplified fragment length polymorphisms (AFLP), phylogeny, Puccinia. INTRODUCTION. Puccinia triticina Eriks ..... Genetic distances and reconstruction phylogenetic trees from microsatellite DNA.

  19. Rust Inhibitor And Fungicide For Cooling Systems

    Science.gov (United States)

    Adams, James F.; Greer, D. Clay

    1988-01-01

    Mixture of benzotriazole, benzoic acid, and fungicide prevents growth of rust and fungus. Water-based cooling mixture made from readily available materials prevents formation of metallic oxides and growth of fungi in metallic pipes. Coolant remains clear and does not develop thick sludge tending to collect in low points in cooling systems with many commercial rust inhibitors. Coolant compatible with iron, copper, aluminum, and stainless steel. Cannot be used with cadmium or cadmium-plated pipes.

  20. 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.

  1. 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.

  2. Modelos de ponto crítico para estimar danos causados pela ferrugem da folha da aveia branca Critical yield models to estimate the damage caused by leaf rust in white oat

    Directory of Open Access Journals (Sweden)

    Erlei Melo Reis

    2008-09-01

    Full Text Available Em experimentos conduzidos no campo, nas safras agrícolas de 1995 e 1996, gerou-se o gradiente da intensidade da ferrugem da folha da aveia branca, cultivar UPF 13, pela aplicação nos órgãos aéreos de doses crescentes do fungicida triadimenol. As equações das funções de dano foram obtidas pela correlação entre o rendimento de grãos e a incidência da doença em diferentes estádios fenológicos da cultura. Na safra de 1995 as equações obtidas foram R= 2.103,5 - 17,983I e R= 2.404,6 - 12,832I, respectivamente para alongamento e emborrachamento, e em 1996, R= 3.889,2 - 27,871I e R= 5.366,4 - 20,999I, respectivamente para emborrachamento e floração (R= rendimento de grãos e I= incidência foliar. Estas equações, contendo o coeficiente de dano, permitem calcular o limiar de dano econômico (LDE tomado como critério indicador do momento para o início do controle químico da ferrugem da folha da aveia. As reduções no rendimento de grãos, no peso do hectolitro e no peso de mil sementes, atingiram, respectivamente 57,13%, 16,64% e 21,49% na safra 1995 e 19,79%, 13,39% e 16,33%, na safra 1996.In field experiments carried out in the 1995 and 1996 growing seasons, the gradient of leaf rust intensity on the white oat cultivar UPF 13 was generated by spraying the above ground plant parts of the crop with different rates of the fungicide triadimenol. Damage equations were obtained relating grain yield and disease incidence at different growing stages. In the 1995 growing season the equations were: R= 2,103.5 -17.983I and R= 2,404.6 - 12.832I, for elongation and boot stage, respectively, and for 1996, R= 3,889.2 - 27.871I and R= 5,366.4 - 20.999I (where R= grain yield; I= disease as foliar incidence, for booting and flowering stages respectively. These equations, having the damage coefficient, may be used to calculate the economic damage threshold (LDE as a criterion to indicate the moment for the fungicide application to control leaf

  3. Detection of soybean rust contamination in soy leaves by FTIR photoacoustic spectroscopy

    Science.gov (United States)

    Andrade, L. H. C.; Freitas, P. G.; Mantovani, B. G.; Figueiredo, M. S.; Lima, R. A.; Lima, S. M.; Rangel, M. A. S.; Mussury, R. M.

    2008-01-01

    In this work the Photoacoustic Infrared Spectroscopy from 4000 to 400 cm-1 was applied, by the first time to our knowledge, to diagnostic the soy bean rust or Asian rust contamination on soy leafs caused by the fungi Phakopsora pachyrhizi. The obtained results shown that a premature, fast and precise diagnosis can be achieved using this technique before it can be detect by the conventional visual method. The early identification of the fungi infection avoid massive lost in the soy production and decrease the intense use of fungicide whose is necessary when the infection is in advanced stagy.

  4. Environment-Friendly Control of Pear Scab and Rust Using Lime Sulfur

    Directory of Open Access Journals (Sweden)

    Ju Hoon Cha

    2018-03-01

    Full Text Available Pear scab and rust are the major diseases causing severe epidemics in organic cultivation of pear trees. Incidences of pear scab and rust were compared in organically managed plots and conventionally managed plots to obtain optimum application schedule of environment-friendly control agents in organically managed plots. Organically cultural practice with 10 time-applications of lime sulfur and Bordeaux mixture showed higher than 40% of control efficacies of pear scab and rust compared to conventionally cultural practice. Organically cultural practice with 8 time-applications of lime sulfur considering weather condition showed higher than 30% of control efficacies of pear scab compared to conventionally cultural practice. The results suggest that proper application of environment-friendly control agents such as lime sulfur considering weather condition will enable effective control of the major diseases for organic cultivation of pear.

  5. METHODS OF OBTAINING LONGITUDINAL STRIPES LAYOUTS

    Directory of Open Access Journals (Sweden)

    OANA Dorina

    2014-05-01

    Full Text Available From the technological point of view it is necessary that the phase of warping to be done two or three multiple warp, which results in two or three rolls of the warp final will meet only the warping. To achieve longitudinal striped fabric spinning machines is necessary to have all tensioning mechanism dispensing rolls which requires their special construction. The homogeneity of the fabric from the point of view of the warp yarns tension must be ensured by synchronizing operation of the tensioning two cutting mechanisms of the two reels on which the wires are wound with a degree of waving and thus the fuel consumption at the different weaving. It is recommended that the design be adopted average float bonds, such that the wires can be wrapped around more than two final reels. In terms of manufacturing technology with longitudinal stripes fabrics have a more complicated and expensive technology to cross-striped fabrics for the manufacture of which technology is simplified. Cross-striped fabrics containing groups of warp threads those linked to floating average is materially different. Due to this degree of crimping of wires in the stripes with different bonds makes their contract to be different, having a direct influence on the wires consumption. The different contraction of wire weaving makes warp yarn length, contained in a linked reports are so different that it requires winding wires with different bonds also differing on the final rolls.

  6. Bioinspired Heterogeneous Structural Color Stripes from Capillaries.

    Science.gov (United States)

    Zhao, Ze; Wang, Huan; Shang, Luoran; Yu, Yunru; Fu, Fanfan; Zhao, Yuanjin; Gu, Zhongze

    2017-12-01

    As an important characteristic of many creatures, structural colors play a crucial role in the survival of organisms. Inspired by these features, an intelligent structural color material with a heterogeneous striped pattern and stimuli-responsivity by fast self-assembly of colloidal nanoparticles in capillaries with a certain diameter range are presented here. The width, spacing, color, and even combination of the structural color stripe patterns can be precisely tailored by adjusting the self-assembly parameters. Attractively, with the integration of a near-infrared (NIR) light responsive graphene hydrogel into the structural color stripe pattern, the materials are endowed with light-controlled reversible bending behavior with self-reporting color indication. It is demonstrated that the striped structural color materials can be used as NIR-light-triggered dynamic barcode labels for the anti-counterfeiting of different products. These features of the bioinspired structural color stripe pattern materials indicate their potential values for mimicking structural color organisms, which will find important applications in constructing intelligent sensors, anti-counterfeiting devices, and so on. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Guiding thermomagnetic avalanches with soft magnetic stripes

    Energy Technology Data Exchange (ETDEWEB)

    Vlasko-Vlasov, V. K.; Colauto, F.; Benseman, T.; Rosenmann, D.; Kwok, W. -K.

    2017-12-01

    We demonstrate the potential for manipulating the ultrafast dynamics of thermomagnetic flux avalanches (TMA) in superconducting films with soft magnetic stripes deposited on the film. By tuning the in-plane magnetization of the stripes, we induce lines of strong magnetic potentials for Abrikosov vortices, resulting in guided slow motion of vortices along the stripe edges and preferential bursts of TMA along the stripes. Furthermore, we show that transversely polarized stripes can reduce the TMA size by diverting magnetic flux away from the major trunk of the TMA into interstripe gaps. Our data indicate that TMAs are launched from locations with enhanced vortex entry barrier, where flux accumulation followed by accelerated vortex discharge significantly reduces the threshold of the applied field ramping speed required for the creation of TMAs. Finally, vortex-antivortex annihilation at the moving front of an expanding TMA can account for the enhanced TMA activity in the receding branches of the sample's magnetization cycle and the preferred propagation of TMAs into maximum trapped flux regions.

  8. 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

  9. Identifying leaf rust resistance gene Lr19 in durum wheat using ...

    African Journals Online (AJOL)

    Leaf rust, caused by Puccinia triticina Eriks., is an important disease affecting durum wheat (Triticum turgidum ssp. durum) worldwide, particularly in the Mediterranean region. The disease can be controlled through the use of plant host resistance. Based on seedling resistance tests of 103 durum genotypes against a bulk of ...

  10. 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...

  11. Rust resistance in seedling families of Pinus albicaulis and Pinus strobiformis and implications for restoration

    Science.gov (United States)

    R. A. Sniezko; A. Kegley; R. Danchok; J. Hamlin; J. Hill; D. Conklin

    2011-01-01

    Infection and mortality levels from Cronartium ribicola, the fungus causing white pine blister rust, are very high in parts of the geographic range of Pinus albicaulis (whitebark pine) and P. strobiformis (Southwestern white pine). Genetic resistance to this non-native fungus will be one of the key factors in maintaining or restoring populations of these species in...

  12. 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.

  13. Preempting the pathogen: Blister rust and proactive management of high-elevation pines

    Science.gov (United States)

    Sue Miller; Anna Schoettle; Kelly Burns; Richard Sniezko; Patty Champ

    2017-01-01

    White pine blister rust has been spreading through western forests since 1910, causing widespread mortality in a group that includes some of the oldest and highest-elevation pines in the United States. The disease has recently reached Colorado and is expected to travel through the southern Rockies. Although it cannot be contained, RMRS researchers and collaborators are...

  14. Discovery of a seventh Rpp soybean rust resistance locus in soybean accession PI 605823

    Science.gov (United States)

    Soybean rust, caused by the obligate biotrophic fungal pathogen Phakopsora pachyrhizi Syd. & Syd, is a disease threat to soybean production in regions of the world with mild winters. Host plant resistance to P. pachyrhizi conditioned by Rpp genes has been found in numerous soybean accessions, and at...

  15. Molecular and cytogenetic characterization of wheat introgression lines carrying the stem rust resistance gene Sr39.

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis Pers.:Pers. f.sp. tritici Eriks. and Henn., poses a serious threat to global wheat production because of the emergence of Pgt-TTKSK (Ug99). The TTKSK resistant gene Sr39 was derived from Aegilops speltoides through chromosome translocation. In this study, we ch...

  16. Label-Free Detection of Soybean Rust Spores using Photonic Crystal Biosensors

    Science.gov (United States)

    Soybean rust, caused by the fungus Phakopsora pachyrhizi, is one of the most devastating foliar diseases affecting soybeans grown worldwide. The disease was reported for the first time in the United States in 2004. Early spore detection, prior to the appearance of visible symptoms, is critical to ef...

  17. Proactive intervention to sustain high-elevation pine ecosystems threatened by white pine blister rust

    Science.gov (United States)

    Anna W. Schoettle; Richard A. Sniezko

    2007-01-01

    Only recently have efforts begun to address how management might prepare currently healthy forests to affect the outcome of invasion by established non-native pests. Cronartium ribicola, the fungus that causes the disease white pine blister rust (WPBR), is among the introductions into North America where containment and eradication have failed; the...

  18. From select agent to established pathogen: The response to Phakopsora pachyrhizi (soybean rust) in North America

    Science.gov (United States)

    The pathogen causing soybean rust, Phakopsora pachyrhizi Syd., was first described in Japan in 1902. The disease was important in the Eastern Hemisphere for many decades before the fungus was reported in Hawaii in 1994, which was followed by reports from countries in Africa and South America. In 200...

  19. A new soybean rust resistance allele from PI 423972 at the Rpp4 locus

    Science.gov (United States)

    Phakopsora pachyrhizi is a fungal pathogen and the cause of Asian soybean rust (SBR). P. pachyrhizi invaded the continental United States in 2004 and has since been a threat to the soybean industry. There are six described loci that harbor resistance to P. pachyrhizi (Rpp) genes. The resistance of P...

  20. First report of Soybean Rust (Phakopsora pachyrhizi) on Florida Beggarweed (Desmodium tortuosum) in Alabama

    Science.gov (United States)

    Soybean rust (SBR), 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 not observed in 2010 or 2011, probably because of the exceptionally dry, hot weather in the region. The pathogen ...

  1. Soybean germplasm accession seedling reactions to soybean rust isolates from Georgia

    Science.gov (United States)

    Soybean rust (SBR), caused by Phakopsora pachyrhizi, is a threat to soybean [Glycine max (L.) Merr.] production in regions of the world where winters are not cold enough to completely eliminate the many hosts of the fungus, so resistant soybean cultivars would be useful in managing this disease. Res...

  2. The IAC stripe82 legacy project

    Science.gov (United States)

    Román, Javier; Fliri, Juergen; Trujillo, Ignacio

    2017-03-01

    We present new deep co-adds of data taken within Stripe 82 of the Sloan Digital Sky Survey (SDSS), especially stacked to reach the faintest surface brightness limits of this data set. Our reduction puts special emphasis on preserving the characteristics of the background (sky + diffuse light) in the input images using a non-aggressive sky subtraction strategy, resulting in an exquisite quality on extremely faint structures. The IAC Stripe 82 co-adds offer a rather unique possibility to study the low surface brightness Universe like stellar haloes and disc truncations, low surface brightness, tidal galactic interactions, extremely faint dwarf galaxies, intra-cluster light or diffuse light from galactic dust. The imaging data is publicly available at http://www.iac.es/proyecto/stripe82/.

  3. 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. PMID:24497941

  4. Improving striping operations through system optimization - phase 2 : final report.

    Science.gov (United States)

    2016-07-01

    Striping operations generate a significant workload for MoDOT maintenance operations. The requirement for each striping crew : to replenish its stock of paint and other consumable items from a bulk storage facility, along with the necessity to make s...

  5. Probing optically silent superfluid stripes in cuprates

    Science.gov (United States)

    Rajasekaran, S.; Okamoto, J.; Mathey, L.; Fechner, M.; Thampy, V.; Gu, G. D.; Cavalleri, A.

    2018-02-01

    In many theoretical models of high-temperature superconductors, remnants of superconductivity persist to temperatures higher than the transition temperature, TC. Rajasekaran et al. used nonlinear terahertz spectroscopy to probe this region of the phase diagram of a cuprate superconductor that is well known for a stripe phase that appears for certain doping levels (see the Perspective by Ergeçen and Gedik). For a sample deep in the stripe phase, a large nonlinear signal persisted from the superconducting region up to temperatures much higher than TC. The findings suggest the formation of a peculiar spatially modulated superconducting state called the pair-density wave.

  6. 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

  7. Marker-assisted pyramiding of Thinopyrumderived leaf rust ...

    Indian Academy of Sciences (India)

    2017-03-20

    Mar 20, 2017 ... (Short Title: Marker assisted pyramiding of leaf rust resistance genes). Key words: Wheat, leaf rust, molecular marker, gene pyramiding,marker assisted selection. Abstract. The study was undertaken to pyramid two effective leaf rust resistance genes (Lr19 and Lr24) derived from Thinopyrum(syn.Agropyron) ...

  8. Frequency of comandra blister rust infection episodes on lodgepole pine

    Science.gov (United States)

    William R. Jacobi; Brian W. Geils; Jane E. Taylor

    2002-01-01

    Comandra blister rust is a damaging canker disease of lodgepole pine in the Central Rocky Mountains. Our knowledge of previous blister rust outbreaks and the effects of weather and climate on rust epidemiology has not been sufficient to explain the frequency and severity of disease outbreaks. Thus, we sought to describe the seasonal and annual frequency and duration of...

  9. Development of wheat germplasm for stem rust resistance in eastern ...

    African Journals Online (AJOL)

    Wheat (Triticum aestivum) rust outbreak is the primary production constraint in Eastern Africa. Ethiopia, Kenya and Uganda are hot spots for the epidemic of rusts, due to higher rates of evolution of new pathogen races, especially of the virulent stem rust (Puccinia graminis) race, Ug99. The objective of this study was to ...

  10. 77 FR 65840 - Chrysanthemum White Rust Regulatory Status and Restrictions

    Science.gov (United States)

    2012-10-31

    ... Inspection Service 7 CFR Part 319 [Docket No. APHIS-2012-0001] RIN 0579-AD67 Chrysanthemum White Rust... should amend our process for responding to domestic chrysanthemum white rust (CWR) outbreaks and the... whether and how we should amend our process for responding to domestic chrysanthemum white rust (CWR...

  11. Development of a Spectrophotometric System to Detect White Striping Physiopathy in Whole Chicken Carcasses

    Science.gov (United States)

    Traffano-Schiffo, Maria Victoria; Castro-Giraldez, Marta; Colom, Ricardo J.; Fito, Pedro J.

    2017-01-01

    Due to the high intensification of poultry production in recent years, white chicken breast striping is one of the most frequently seen myopathies. The aim of this research was to develop a spectrophotometry-based sensor to detect white striping physiopathy in chicken breast meat in whole chicken carcasses with skin. Experiments were carried out using normal and white striping breasts. In order to understand the mechanism involved in this physiopathy, the different tissues that conform each breast were analyzed. Permittivity in radiofrequency (40 Hz to 1 MHz) was measured using two different sensors; a sensor with two flat plates to analyze the whole breast with skin (NB or WSB), and a two needles with blunt-ended sensor to analyze the different surface tissues of the skinless breast. In the microwave range (500 MHz to 20 GHz), permittivity was measured as just was described for the two needles with blunt-ended sensor. Moreover, fatty acids composition was determined by calorimetry techniques from −40 °C to 50 °C at 5 °C/min after previously freeze-drying the samples, and pH, microstructure by Cryo-SEM and binocular loupe structure were also analyzed. The results showed that the white striping physiopathy consists of the partial breakdown of the pectoral muscle causing an increase in fatty acids, reducing the quality of the meat. It was possible to detect white striping physiopathy in chicken carcasses with skin using spectrophotometry of radiofrequency spectra. PMID:28471378

  12. DNA methylation profiles correlated to striped bass sperm fertility

    Science.gov (United States)

    Striped bass (Morone saxatilis) spermatozoa are used to fertilize in vitro the eggs of white bass (Morone chrysops) to produce the preferred hybrid for the striped bass aquaculture industry. Currently, only one source of domestic striped bass juveniles are available to growers that are not obtained ...

  13. Amino acid uptake in rust fungi

    Directory of Open Access Journals (Sweden)

    Christine eStruck

    2015-02-01

    Full Text Available 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 tranporter 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.

  14. Breakup Behavior of a Capillary Bridge on a Hydrophobic Stripe Separating Two Hydrophilic Stripes

    Science.gov (United States)

    Hartmann, Maximilian; Hardt, Steffen

    2017-11-01

    The breakup dynamics of a capillary bridge on a hydrophobic area between two liquid filaments occupying two parallel hydrophilic stripes is studied experimentally. In addition calculations with the finite-element software Surface Evolver are performed to obtain the corresponding stable minimal surfaces. Droplets of de-ionized water are placed on substrates with alternating hydrophilic and hydrophobic stripes of different width. Their volume decreases by evaporation. This results in a droplet shaped as the letter ``H'' covering two hydrophilic stripes separated by one hydrophobic stripe. The width of the capillary bridge d(t) on the hydrophobic stripe during the breakup process is observed using a high-speed camera mounted on a bright-field microscope. The results of the experiments and the numerical studies show that the critical width dcrit, indicating the point where the capillary bridge becomes unstable, mainly depends on the width ratio of the hydrophilic and hydrophobic stripes. It is found that the time derivative of d(t) first decreases after dcrit has been reached. The final breakup dynamics then follows a t 2 / 3 scaling. We kindly acknowledge the financial support by the German Research Foundation (DFG) within the Collaborative Research Centre 1194 ``Interaction of Transport and Wetting Processes'', Project A02a.

  15. 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...

  16. Phakopsora pachyrhizi, the causal agent of Asian soybean rust.

    Science.gov (United States)

    Goellner, Katharina; Loehrer, Marco; Langenbach, Caspar; Conrath, Uwe; Koch, Eckhard; Schaffrath, Ulrich

    2010-03-01

    The plant pathogenic basidiomycete fungi Phakopsora pachyrhizi and Phakopsora meibomiae cause rust disease in soybean plants. Phakopsora pachyrhizi originated in Asia-Australia, whereas the less aggressive P. meibomiae originated in Latin America. In the New World, P. pachyrhizi was first reported in the 1990s to have spread to Hawaii and, since 2001, it has been found in South America. In 2004, the pathogen entered continental USA. This review provides detailed information on the taxonomy and molecular biology of the pathogen, and summarizes strategies to combat the threat of this devastating disease. Phakopsora pachyrhizi Syd. & P. Syd; uredial anamorph: Malupa sojae (syn. Uredo sojae); Domain Eukaryota; Kingdom Fungi; Phylum Basidiomycota; Order Uredinales; Class Urediniomycetes; Family Phakopsoraceae; Genus Phakopsora (http://www.indexfungorum.org). The nomenclature of rust spores and spore-producing structures used within this review follows Agrios GN (2005) Plant Pathology, 5th edn. London: Elsevier/Academic Press. In the field, P. pachyrhizi infects leaf tissue from a broad range (at least 31 species in 17 genera) of leguminous plants. Infection of an additional 60 species in other genera has been achieved under laboratory conditions. At the beginning of the disease, small, tan-coloured lesions, restricted by leaf veins, can be observed on infected soybean leaves. Lesions enlarge and, 5-8 days after initial infection, rust pustules (uredia, syn. uredinia) become visible. Uredia develop more frequently in lesions on the lower surface of the leaf than on the upper surface. The uredia open with a round ostiole through which uredospores are released.

  17. Protein modeling of yellow rust disease in wheat

    International Nuclear Information System (INIS)

    Aziz, S.E.; Bano, R.; Zayed, M.E.; Elshikh, M.S.; Khan, M.H.; Chaudhry, Z.

    2017-01-01

    Wheat production in Pakistan is affected by yellow rust disease caused by a fungus Puccinia striiformis. There is a need to broaden the genetic basis of wheat by identifying new resistance genes. The present study was aimed to identify an alternate resistance gene for yellow rust disease in wheat caused by Puccinia striiformis. Genome sequence was compared with databases and similar gene was identified for disease resistance in rye plant. Structural analysis of RGA1 gene (resistance gene in wheat) was carried out using different bioinformatics tools and an alternative gene having same structure was identified on the basis of structural and sequence homology. Rye plant is the proposed plant for the alternate new resistance gene. The result of pairwise alignment of RGA1 gene in wheat and gene of rye plant is 94.2% with accession DQ494535 .The secondary structures of both the genes was compared and found similar to each other. These comparisons between the wheat resistance gene and gene from rye plant depict structural similarities between the two genes. Results of RGA1 gene's structural analysis in wheat is as follow: Helices: 59, Extended sheets: 30, Turns: 12, Coils: 13 and for alternate resistance genes in Rye is as follow: Helices: 52, Extended sheets: 30, Turns: 14, Coils: 17. As structures are similar, the alternate identified gene could be used for resistance in wheat. (author)

  18. Post-epizootic chronic dolphin morbillivirus infection in Mediterranean striped dolphins Stenella coeruleoalba.

    Science.gov (United States)

    Soto, Sara; Alba, Ana; Ganges, Llilianne; Vidal, Enric; Raga, Juan Antonio; Alegre, Ferrán; González, Beatriz; Medina, Pascual; Zorrilla, Irene; Martínez, Jorge; Marco, Alberto; Pérez, Mónica; Pérez, Blanca; Pérez de Vargas Mesas, Ana; Martínez Valverde, Rosa; Domingo, Mariano

    2011-10-06

    Dolphin morbillivirus (DMV) has caused 2 epizootics with high mortality rates on the Spanish Mediterranean coast, in 1990 and 2006-07, mainly affecting striped dolphins Stenella coeruleoalba. Following the first epizootic unusual DMV infections affecting only the central nervous system of striped dolphins were found, with histological features similar to subacute sclerosing panencephalitis and old dog encephalitis, the chronic latent localised infections caused by defective forms of measles virus and canine distemper virus, respectively. Between 2008 and 2010, monitoring by microscopic and immunohistochemical (IHC) studies of 118 striped dolphins stranded along Catalonia, the Valencia Region and Andalusia showed similar localised DMV nervous system infections in 25.0, 28.6 and 27.4% of cases, respectively, with no significant differences among regions or sex. The body length of DMV-infected dolphins was statistically greater than that of non-infected dolphins (196.5 vs. 160.5 cm; p dolphins with positive IHC-DMV had positive PCR results. All 6 cases were positive with the 78 bp RT-PCR. These findings contraindicate the use of the 429 bp RT-PCR protocol based on the P gene to detect this specific form of DMV. DMV localised nervous infection constitutes the most relevant single cause of stranding and death in Mediterranean striped dolphins in the years following a DMV epizootic, and it might even overwhelm the effects of the epizootic itself, at least in 2007.

  19. Determination of the quality of stripe-marked and cracked eggs during storage

    Directory of Open Access Journals (Sweden)

    Yu Chi Liu

    2017-07-01

    Full Text Available Objective Stripe marks, which occasionally occur on the shell, do not cause breakage to the shell and shell membranes of eggs. This study investigated the quality of intact eggs (IEs, minor stripe-marked eggs (MEs, severe stripe-marked eggs (SEs, and cracked eggs (CEs during 3-week storage at 25°C. Methods Shell eggs were collected the day after being laid and were washed. Among them, eggs without any visual cracks or stripe marks on the shells were evaluated as IEs by the plant employees using candling in a darkened egg storage room; the remaining eggs exhibited some eggshell defects. At day 3, the eggs were further categorized into IEs, MEs, SEs, CEs, and broken eggs (BEs on the basis of the description given. Except BEs, which were discarded, the remaining eggs were stored at 25°C (approximate relative humidity 50% and then analyzed. Results Stripe marks were observed primarily within the first 3 days after washing. At day 3, CEs had significantly (p<0.05 lower Haugh unit values, but all eggs had grades AA or A, according to the United States Department of Agriculture standard. As storage time increased, differences in egg quality between groups were more obvious. IEs had the highest eggshell breaking strength. During storage, the total plate counts and pathogens, namely Escherichia coli, Campylobacter spp., Staphylococcus aureus, and Salmonella spp., were not detectable in the internal content of IEs and SEs. Conclusion In conclusion, cracks degraded egg quality severely and minor stripe marks only slightly influenced the egg quality.

  20. Rust dissolution and removal by iron-reducing bacteria: A potential rehabilitation of rusted equipment

    International Nuclear Information System (INIS)

    Starosvetsky, J.; Kamari, R.; Farber, Y.; Bilanović, D.; Armon, R.

    2016-01-01

    Highlights: • The present study demonstrated the high reductive capacity of both strains: the collection S. oneidensis and the wild strain Geobacter spp. (soil isolate). • The experimental strains were successful in Fe 3+ reduction for both states: soluble and crystalline (originally prepared from rust). • Rust dissolution can be improved by: addition of AFC at low concentration (0.2 g/l), increasing bacterial initial inoculum and rust reactive surface. • Both experimental IRB strains were able to completely remove previously formed rust on carbon steel coupons. • Additional results (not showed) revealed that culture S. oneidensis and the environmental isolate Geobacter spp., apparently have a different mechanism of iron reduction that requires further study. - Abstract: Iron reducing bacteria (IRB), to be used in rust dissolution and removal, have been isolated and enriched from different environmental sources. Comparative measurements revealed that a soil isolate (Geobacter sulfurreducens sp.) had the highest reductive activity equivalent to Shewanella oneidensis (strain CIP 106686, pure culture). Both reductive microorganisms can use Fe 3+ ions as electron acceptors from soluble as well as from crystalline sources. In nutrient medium containing soluble Fe 3+ , the highest reductive activity obtained for G. sulfurreducens sp. and S. oneidensis was 93 and 97% respectively. Successful removal of rust from carbon steel coupons has been achieved with both experimental bacteria.

  1. Genotype-by-sequencing facilitates genetic mapping of a stem rust resistance locus in Aegilops umbellulata, a wild relative of cultivated wheat.

    Science.gov (United States)

    Edae, Erena A; Olivera, Pablo D; Jin, Yue; Poland, Jesse A; Rouse, Matthew N

    2016-12-15

    Wild relatives of wheat play a significant role in wheat improvement as a source of genetic diversity. Stem rust disease of wheat causes significant yield losses at the global level and stem rust pathogen race TTKSK (Ug99) is virulent to most previously deployed resistance genes. Therefore, the objective of this study was to identify loci conferring resistance to stem rust pathogen races including Ug99 in an Aegilops umbelluata bi-parental mapping population using genotype-by-sequencing (GBS) SNP markers. A bi-parental F 2:3 population derived from a cross made between stem rust resistant accession PI 298905 and stem rust susceptible accession PI 542369 was used for this study. F 2 individuals were evaluated with stem rust race TTTTF followed by testing F 2:3 families with races TTTTF and TTKSK. The segregation pattern of resistance to both stem rust races suggested the presence of one resistance gene. A genetic linkage map, comprised 1,933 SNP markers, was created for all seven chromosomes of Ae. umbellulata using GBS. A major stem rust resistance QTL that explained 80% and 52% of the phenotypic variations for TTTTF and TTKSK, respectively, was detected on chromosome 2U of Ae. umbellulata. The novel resistance gene for stem rust identified in this study can be transferred to commercial wheat varieties assisted by the tightly linked markers identified here. These markers identified through our mapping approach can be a useful strategy to identify and track the resistance gene in marker-assisted breeding in wheat.

  2. Susceptibility to Rust (Puccinia Sp. in Cultivars of Italian and Perennial Ryegrass Grown in Two Locations of Italy

    Directory of Open Access Journals (Sweden)

    Luigi Russi

    2009-03-01

    Full Text Available A large set of foreign varieties of Italian ryegrass (Lolium multiflorum and perennial ryegrass (L. perenne were evaluated for their response to natural rust infection in two Italian locations (Lodi in the north; Perugia in the centre of the country at three-year intervals in 2001, 2004 and 2007, to acquire information on novel germplasm for Italy and verify any spatial and temporal variation in the varietal response to the disease. Crown rust (caused by Puccinia coronata on Italian ryegrass and stem rust (caused by P. graminis on perennial rygrass were consistently recorded in appreciable amount (average susceptibility score > 2.0 on a 1-9 scale. Vice-versa, crown rust on perennial and stem rust on Italian ryegrass seldom affected appreciably the crop. Strong interactions of variety response (to the prevailing pathogen with locations and years of evaluation were observed in both ryegrasses. Subsequently, the repeatability of results between locations, or between years within locations, as measured by rank correlations of variety scores, was sometimes only moderate or low. However, despite such interactions, a few promising varieties were identified in each species with consistently low susceptibility across evaluation environments, which deserve further investigation for a possible direct utilisation, or as donors of useful genes for breeding purposes.

  3. Susceptibility to Rust (Puccinia Sp. in Cultivars of Italian and Perennial Ryegrass Grown in Two Locations of Italy

    Directory of Open Access Journals (Sweden)

    Luciano Pecetti

    2011-02-01

    Full Text Available A large set of foreign varieties of Italian ryegrass (Lolium multiflorum and perennial ryegrass (L. perenne were evaluated for their response to natural rust infection in two Italian locations (Lodi in the north; Perugia in the centre of the country at three-year intervals in 2001, 2004 and 2007, to acquire information on novel germplasm for Italy and verify any spatial and temporal variation in the varietal response to the disease. Crown rust (caused by Puccinia coronata on Italian ryegrass and stem rust (caused by P. graminis on perennial rygrass were consistently recorded in appreciable amount (average susceptibility score > 2.0 on a 1-9 scale. Vice-versa, crown rust on perennial and stem rust on Italian ryegrass seldom affected appreciably the crop. Strong interactions of variety response (to the prevailing pathogen with locations and years of evaluation were observed in both ryegrasses. Subsequently, the repeatability of results between locations, or between years within locations, as measured by rank correlations of variety scores, was sometimes only moderate or low. However, despite such interactions, a few promising varieties were identified in each species with consistently low susceptibility across evaluation environments, which deserve further investigation for a possible direct utilisation, or as donors of useful genes for breeding purposes.

  4. Induced mutations for tolerance of oats to crown rust

    International Nuclear Information System (INIS)

    Simons, M.D.; Frey, K.J.

    1977-01-01

    Seeds of three oat (Avena sativa and A. abyssinica) strains were treated with ethyl methanesulphonate (EMS), and crown rust (caused by Puccinia coronata var. avenae) tolerance ratios of M 5 -derived lines were compared with untreated checks. Tolerance ratios of mutant lines tended to be distributed in both plus and minus directions. No mutant oat line had a significant increase in grain yield, but many showed significantly depressed yields. With C.I. 6665, only five of 130 mutagen-derived lines were not significantly below the check for grain yield; one of these had significantly improved tolerance. Re-treatment of selected strains from a previous EMS treatment (original cultivar was Clintland-60) gave one M 5 -derived oat line (of 100 tested) that was equal to Clintland-60 in grain yield and sustained no damage from crown rust (i.e. it had a tolerance ratio of 100). EMS treatment of the highly susceptible tetraploid C.I. 2110 resulted in both significantly increased and reduced tolerance. (author)

  5. Epidemiology of bean rust in Ethiopia

    NARCIS (Netherlands)

    Habtu, A.

    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

  6. 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

  7. Induced mutations for soybean rust resistance

    International Nuclear Information System (INIS)

    Smutkupt, S.; Wongpiyasatid, A.; Lamseejan, S.

    1983-01-01

    Soybean mutation experiments for inducing rust resistance in the cultivars G 8375, Wakashima mutant number 10, Taichung N, S.J.2, S.J.4, BM 50, BM 98, G 8377, G 8586 and G 8587 have been carried out since 1979. Six pods from each of 4438 control and 43,907 M 1 plants were randomly harvested. M 2 seeds of each cultivar of different doses were bulked (M 2 bulk). In addition, 270 good M 1 plants were selected and threshed singly (M 2 single). M 2 -bulk and M 2 -single seeds were advanced to M 3 . Both, M 3 -bulk and M 3 -single plants, together with the remaining M 2 -bulk seeds were screened for rust resistance in the rainy season of 1980 in Nong Hoi Valley (altitude about 1000 m above sea level) and at Mae Joe Station, both in Chiang Mai Province (latitude 18 deg. 31'-19 deg. N). Based on the IWGSR rating system, soybean plants with slow growth of rust were selected from both locations. The results were as follows: Six plants were selected from a total of 2802 control plants, and 115 from a total of 28,834 M 2 and M 3 plants. Further evaluation of these selections for rust resistance will be carried out in the rainy season of 1981 in Nong Hoi Valley, Chiang Mai. (author)

  8. Molecular genetic variability of Australian isolates of five cereal rust pathogens.

    Science.gov (United States)

    Keiper, Felicity J; Hayden, Matthew J; Park, Robert F; Wellings, Colin R

    2003-05-01

    Rust fungi cause economically important diseases of cereals, and their ability to rapidly evolve new virulent races has hindered attempts to control them by genetic resistance. PCR-based molecular tools may assist in understanding the genetic structure of pathogen populations. The high multiplex DNA fingerprinting techniques, amplified fragment length polymorphisms (AFLP), selectively amplified microsatellites (SAM) and sequence-specific amplification polymorphisms (S-SAP) were assessed for their potential in investigations of the genetic relationships among isolates of the wheat rust pathogens, Puccinia graminis f. sp. tritici (Pgt), Puccinia triticina (Pt), and P. striiformis f. sp. tritici (Pst), the oat stem rust pathogen P. graminis f. sp. avenae (Pga), and a putative new P. striiformis special form tentatively designated Barley grass yellow rust (Bgyr). Marker information content, as indicated by the number of species-specific fragments, polymorphic fragments among pathotypes, percentage of polymorphic loci, and the marker index, was highest for the SAM assay, followed by the AFLP and S-SAP assays. UPGMA analysis revealed that all marker types efficiently discriminated the five different taxa and Mantel tests revealed significant correlations between the marker types. Within pathogen groups, the marker types differed in the amount of variation detected among isolates; however, the major differences were consistent and polymorphism was generally low. This was reflected by the AMOVA analysis that significantly partitioned 90% of the genetic variation between taxa. Of the three marker types, SAMS were the most informative, and have the potential for the development of locus-specific microsatellites.

  9. Flavonoid Accumulation Plays an Important Role in the Rust Resistance of Malus Plant Leaves

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    Yanfen Lu

    2017-07-01

    Full Text Available Cedar-apple rust (Gymnosporangium yamadai Miyabe is a fungal disease that causes substantial injury to apple trees and results in fruit with reduced size and quality and a lower commercial value. The molecular mechanisms underlying the primary and secondary metabolic effects of rust spots on the leaves of Malus apple cultivars are poorly understood. Using HPLC, we found that the contents of flavonoid compounds, especially anthocyanin and catechin, were significantly increased in rust-infected symptomatic tissue (RIT. The expression levels of structural genes and MYB transcription factors related to flavonoid biosynthesis were one- to seven-fold higher in the RIT. Among these genes, CHS, DFR, ANS, FLS and MYB10 showed more than a 10-fold increase, suggesting that these genes were expressed at significantly higher levels in the RIT. Hormone concentration assays showed that the levels of abscisic acid (ABA, ethylene (ETH, jasmonate (JA and salicylic acid (SA were higher in the RIT and were consistent with the expression levels of McNCED, McACS, McLOX and McNPR1, respectively. Our study explored the complicated crosstalk of the signal transduction pathways of ABA, ETH, JA and SA; the primary metabolism of glucose, sucrose, fructose and sorbitol; and the secondary metabolism of flavonoids involved in the rust resistance of Malus crabapple leaves.

  10. Modification of tolerance of oats to crown rust induced by chemical mutagens

    International Nuclear Information System (INIS)

    Simons, M.D.; Browning, J.A.; Frey, K.J.

    1983-01-01

    Seeds of crown rust (Puccinia coronata) susceptible cultivated oats (Avena sativa) were treated with the mutagenic chemical ethyl methanesulphonate (EMS), and pure lines derived from these treated seeds were tested in later generations for the relative amount of reduction in yield and seed weight caused by crown rust infection. In the absence of crown rust, the yield of most of the treated lines was greatly reduced. The overall means of the treated lines for both yield and seed weight response to infection were significantly lower than the control, but 10 lines significantly exceeded the control for yield response and 15 exceeded it for seed weight response. Recurrent EMS treatment of once-treated lines rated as tolerant resulted in groups of lines that were more tolerant, on the average, than groups of lines from recurrently treated lines rated as susceptible. A few of the recurrently treated individual lines derived from tolerant parents had a higher degree of tolerance than their parental lines. EMS treatment of diploid (A. strigosa) and tetraploid (A. abyssinica) oats resulted in groups of lines showing significant genetic variance for response to crown rust, indicating that treatment had induced real genetic change. A few diploid lines were a little more tolerant than their control, but none of the tetraploid lines showed any consistent improvement. (author)

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Transcriptome analysis of resistant and susceptible genotypes of Glycine tomentella during Phakopsora pachyrhizi infection reveals novel rust resistance genes.

    Science.gov (United States)

    Soria-Guerra, Ruth Elena; Rosales-Mendoza, Sergio; Chang, Sungyul; Haudenshield, James S; Padmanaban, Annamalai; Rodriguez-Zas, Sandra; Hartman, Glen L; Ghabrial, Said A; Korban, Schuyler S

    2010-05-01

    Soybean rust, caused by Phakopsora pachyrhizi, is a destructive foliar disease in nearly all soybean-producing countries. To identify genes controlling resistance to soybean rust, transcriptome profiling was conducted in resistant and susceptible Glycine tomentella genotypes triggered by P. pachyrhizi infection. Among 38,400 genes monitored using a soybean microarray, at 5% false discovery rate, 1,342 genes were identified exhibiting significant differential expression between uninfected and P. pachyrhizi-infected leaves at 12, 24, 48, and 72 h post-inoculation (hpi) in both rust-susceptible and rust-resistant genotypes. Differentially expressed genes were grouped into 12 functional categories, and among those, large numbers relate to basic plant metabolism. Transcripts for genes involved in the phenylpropanoid pathway were up-regulated early during rust infection. Similarly, genes coding for proteins related to stress and defense responses such as glutathione-S-transferases, peroxidases, heat shock proteins, and lipoxygenases were consistently up-regulated following infection at all four time points. Whereas, subsets of genes involved in cellular transport, cellular communication, cell cycle, and DNA processing were down-regulated. Quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) on randomly selected genes from the different categories confirmed these findings. Of differentially expressed genes, those associated with the flavonoid biosynthesis pathway as well as those coding for peroxidases and lipoxygenases were likely to be involved in rust resistance in soybean, and would serve as good candidates for functional studies. These findings provided insights into mechanisms underlying resistance and general activation of plant defense pathways in response to rust infection.

  16. Crystal shapes on striped surface domains

    International Nuclear Information System (INIS)

    Valencia, Antoni

    2004-01-01

    The equilibrium shapes of a simple cubic crystal in contact with a planar chemically patterned substrate are studied theoretically using an effective interface model. The substrate is primarily made of lyophobic material and is patterned with a lyophilic (easily wettable) stripe domain. Three regimes can be distinguished for the equilibrium shapes of the crystal. The transitions between these regimes as the volume of the crystal is changed are continuous or discontinuous depending on the strength of the couplings between the crystal and the lyophilic and lyophobic surface domains. If the crystal grows through a series of states close to equilibrium, the discontinuous transitions correspond to growth instabilities. These transitions are compared with similar results that have been obtained for a volume of liquid wetting a lyophilic stripe domain

  17. Possibility of cereals protection against rusts by resistant breeding method

    Directory of Open Access Journals (Sweden)

    Czesław Zamorski

    2013-12-01

    Full Text Available In the years 1999-2001 field trials were run on susceptibility of wheat and triticale genotypes to infection by three rust fungi (Puccinia recondita, Puccinia graminis, Puccinia striiformis. The results of the observation of the infection level in following years have been similar. Among genotypes of winter wheat, breeding lines susceptible to Puccinia striiformis infection were rare, but among spring wheat 50% of genotypes were susceptible to yellow rust infection. A much higher level of sensitivity than in the case of winter wheat has been found in winter triticale genotypes. Wheat genotypes were distinguished by the high sensitivity to Puccinia graminis infection, only a few breeding lines were resistant to stem rust. The susceptibility of wheat to brown rust (Puccinia recondita was a common feature. Triticale genotypes compared to wheat were affected significantly less and majority of them exhibited high level of resistant to brown rust. The use of the breeding method has justification in control yellow rust of winter wheat. Recommended cultivars are almost all fully resistant to Puccinia striiformis infection. The application of this method in selection of spring wheat and triticale is in large past limited. Some of the registered cultivars of spring wheat and triticale are very susceptible to yellow rust. Using the breeding method to protect wheat from stem rust and brown rust is of little practical benefit in our county at this moment. But it can be effecive to control stem and brown rusts of triticale.

  18. The preparation of immunochromatographic stripe of methamphetamine

    International Nuclear Information System (INIS)

    Jiang Jing; Liu Yibing; Zhou Ling; Guo Weizheng

    2004-01-01

    A gold immunochromatographic assay (GICA) is developed for methamphetamine in urine. Colloidal gold is obtained by reducing the gold chloride with sodium citrate, and labeled methamphetamine monoclonal antibody. The drug or metabolite competes with the immobilized drug conjugate in the test area for the limited colloidal gold-labeled antibody complex in which the stripe is made to screen the drug abuser. This method has sensitivity of 1000 μg/L, and without cross-reaction with some drugs

  19. 3D face recognition using isogeodesic stripes.

    Science.gov (United States)

    Berretti, Stefano; Del Bimbo, Alberto; Pala, Pietro

    2010-12-01

    In this paper, we present a novel approach to 3D face matching that shows high effectiveness in distinguishing facial differences between distinct individuals from differences induced by nonneutral expressions within the same individual. The approach takes into account geometrical information of the 3D face and encodes the relevant information into a compact representation in the form of a graph. Nodes of the graph represent equal width isogeodesic facial stripes. Arcs between pairs of nodes are labeled with descriptors, referred to as 3D Weighted Walkthroughs (3DWWs), that capture the mutual relative spatial displacement between all the pairs of points of the corresponding stripes. Face partitioning into isogeodesic stripes and 3DWWs together provide an approximate representation of local morphology of faces that exhibits smooth variations for changes induced by facial expressions. The graph-based representation permits very efficient matching for face recognition and is also suited to being employed for face identification in very large data sets with the support of appropriate index structures. The method obtained the best ranking at the SHREC 2008 contest for 3D face recognition. We present an extensive comparative evaluation of the performance with the FRGC v2.0 data set and the SHREC08 data set.

  20. Classifying Variable Sources in SDSS Stripe 82

    Science.gov (United States)

    Willecke Lindberg, Christina

    2018-01-01

    SDSS (Sloan Digital Sky Survey) Stripe 82 is a well-documented and researched region of the sky that does not have all of its ~67,500 variable objects labeled. By collecting data and consulting different catalogs such as the Catalina Survey, we are able to slowly cross-match more objects and add classifications within the Stripe 82 catalog. Such matching is performed either by pairing SDSS identification numbers, or by converting and comparing the coordinates of every object within the Stripe 82 catalog to every object within the classified catalog, such as the Catalina Survey catalog. If matching is performed with converted coordinates, a follow-up check is performed to ascertain that the magnitudes of the paired objects are within a reasonable margin of error and that objects have not been mismatched. Once matches have been confirmed, the light curves of classified objects can then be used to determine features that most effectively separate the different types of variable objects in feature spaces. By classifying variable objects, we can construct a reference for subsequent large research surveys, such as LSST (the Large Synoptic Survey Telescope), that could utilize SDSS data as a training set for its own classifications.

  1. Occupational Noise Reduction in CNC Striping Process

    Science.gov (United States)

    Mahmad Khairai, Kamarulzaman; Shamime Salleh, Nurul; Razlan Yusoff, Ahmad

    2018-03-01

    Occupational noise hearing loss with high level exposure is common occupational hazards. In CNC striping process, employee that exposed to high noise level for a long time as 8-hour contributes to hearing loss, create physical and psychological stress that reduce productivity. In this paper, CNC stripping process with high level noises are measured and reduced to the permissible noise exposure. First condition is all machines shutting down and second condition when all CNC machine under operations. For both conditions, noise exposures were measured to evaluate the noise problems and sources. After improvement made, the noise exposures were measured to evaluate the effectiveness of reduction. The initial average noise level at the first condition is 95.797 dB (A). After the pneumatic system with leakage was solved, the noise reduced to 55.517 dB (A). The average noise level at the second condition is 109.340 dB (A). After six machines were gathered at one area and cover that area with plastic curtain, the noise reduced to 95.209 dB (A). In conclusion, the noise level exposure in CNC striping machine is high and exceed the permissible noise exposure can be reduced to acceptable levels. The reduction of noise level in CNC striping processes enhanced productivity in the industry.

  2. 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.

  3. Rapid Phenotyping Adult Plant Resistance to Stem Rust in Wheat Grown under Controlled Conditions.

    Science.gov (United States)

    Riaz, Adnan; T Hickey, Lee

    2017-01-01

    Stem rust (SR) or black rust caused by Puccinia graminis f. sp. tritici is one of the most common diseases of wheat (Triticum aestivum L.) crops globally. Among the various control measures, the most efficient and sustainable approach is the deployment of genetically resistant cultivars. Traditionally, wheat breeding programs deployed genetic resistance in cultivars, but unknowingly this is often underpinned by a single seedling resistance gene, which is readily overcome by the pathogen. Nowadays, adult plant resistance (APR) is a widely adopted form of rust resistance because more durable mechanisms often underpin it. However, only a handful of SR APR genes are available, so breeders currently strive to combine seedling and APR genes. Phenotyping adult wheat plants for resistance to SR typically involves evaluation in the field. But establishing a rust nursery can be challenging, and screening is limited to once a year. This slows down research efforts to isolate new APR genes and breeding of genetically resistant cultivars.In this study, we report a protocol for rapid evaluation of adult wheat plants for resistance to stem rust. We demonstrate the technique by evaluating a panel of 16 wheat genotypes consisting of near isogenic lines (NILs) for known Sr genes (i.e., Sr2, Sr33, Sr45, Sr50, Sr55, Sr57, and Sr58) and three landraces carrying uncharacterized APR from the N. I. Vavilov Institute of Plant Genetic Resources (VIR). The method can be completed in just 10 weeks and involves two inoculations: first conducted at seedling stage and a second at the adult stage (using the same plants). The technique can detect APR, such as that conferred by APR gene Sr2, along with pseudo-black chaff (the morphological marker). Phenotyping can be conducted throughout the year, and is fast and resource efficient. Further, the phenotyping method can be applied to screen breeding populations or germplasm accessions using local or exotic races of SR.

  4. 3D Measurement Technology by Structured Light Using Stripe-Edge-Based Gray Code

    International Nuclear Information System (INIS)

    Wu, H B; Chen, Y; Wu, M Y; Guan, C R; Yu, X Y

    2006-01-01

    The key problem of 3D vision measurement using triangle method based on structured light is to acquiring projecting angle of projecting light accurately. In order to acquire projecting angle thereby determine the corresponding relationship between sampling point and image point, method for encoding and decoding structured light based on stripe edge of Gray code is presented. The method encoded with Gray code stripe and decoded with stripe edge acquired by sub-pixel technology instead of pixel centre, so latter one-bit decoding error was removed. Accuracy of image sampling point location and correspondence between image sampling point and object sampling point achieved sub-pixel degree. In addition, measurement error caused by dividing projecting angle irregularly by even-width encoding stripe was analysed and corrected. Encoding and decoding principle and decoding equations were described. Finally, 3dsmax and Matlab software were used to simulate measurement system and reconstruct measured surface. Indicated by experimental results, measurement error is about 0.05%

  5. Phylogenetic studies in Ravenelia esculenta and related rust fungi

    OpenAIRE

    Gandhe, K. R.; Kuvalekar, Aniket

    2007-01-01

    Ravenelia esculenta Naras. and Thium. is a rust fungus, which infects mostly thorns, inflorescences, flowers and fruits of Acacia eburnea Willd. Aecial stages of the rust produce hypertrophy in infected parts. DNA of the rust fungus was isolated from aeciospores by ‘freeze thaw’ method. 18S rDNA was amplified and sequenced by automated DNA sequencer. BLAST of the sequence at NCBI retrieved 96 sequences producing significant alignments. Multiple sequence alignment of these sequences was done b...

  6. Identification of Nine Pathotype-Specific Genes Conferring Resistance to Fusiform Rust in Loblolly Pine (Pinus taeda L.

    Directory of Open Access Journals (Sweden)

    Henry V. Amerson

    2015-08-01

    Full Text Available Nearly two decades of research on the host-pathogen interaction in fusiform rust of loblolly pine is detailed. Results clearly indicate that pathotype-specific genes in the host interacting with pathogen avirulence cause resistance as defined by the non-gall phenotype under favorable environmental conditions for disease development. In particular, nine fusiform rust resistance genes (Fr genes are described here including the specific methods to determine each and their localization on the reference genetic map of loblolly pine. Understanding how these and other apparent Fr genes in loblolly pine and other rust-susceptible pines impact resistance screening, parental and progeny selection, and family and clonal deployment is an important area in forest genetics research and operational tree breeding. The documentation of these Fr genes is a key piece of information towards gaining that understanding and ultimately improving breeding and deployment strategies.

  7. Biological control of yellow rust of wheat (Puccinia striiformis) with Serenade®ASO (Bacillus subtilis strain QST713)

    DEFF Research Database (Denmark)

    Reiss, Antje; Jørgensen, Lise Nistrup

    2017-01-01

    Yellow rust (Puccinia striiformis f. sp. tritici) is an important disease in wheat causing significant yield reductions, if not effectively controlled. The biofungicide Bacillus subtilis strain QST 713 suspension concentrate (Serenade®ASO) was investigated for its potential for yellow rust control...... in winter wheat field trials. Serenade®ASO reduced severity of yellow rust significantly, providing up to 60% control at BBCH growth stage 65–69, under moderate disease pressure. Under high disease pressure reductions were more variable and provided less than 30% control. An increase in the number......, but responses to biofungicide were only significant in a few cases, and in all cases the level of control and yield responses were significantly lower compared with using prothioconazole as chemical control. An outdoor pot trial using artificial inoculation tested preventive and curative application of Serenade...

  8. Genomic Prediction of Genetic Values for Resistance to Wheat Rusts

    Directory of Open Access Journals (Sweden)

    Leonardo Ornella

    2012-11-01

    Full Text Available Durable resistance to the rust diseases of wheat ( L. can be achieved by developing lines that have race-nonspecific adult plant resistance conferred by multiple minor slow-rusting genes. Genomic selection (GS is a promising tool for accumulating favorable alleles of slow-rusting genes. In this study, five CIMMYT wheat populations evaluated for resistance were used to predict resistance to stem rust ( and yellow rust ( using Bayesian least absolute shrinkage and selection operator (LASSO (BL, ridge regression (RR, and support vector regression with linear or radial basis function kernel models. All parents and populations were genotyped using 1400 Diversity Arrays Technology markers and different prediction problems were assessed. Results show that prediction ability for yellow rust was lower than for stem rust, probably due to differences in the conditions of infection of both diseases. For within population and environment, the correlation between predicted and observed values (Pearson’s correlation [ρ] was greater than 0.50 in 90% of the evaluations whereas for yellow rust, ρ ranged from 0.0637 to 0.6253. The BL and RR models have similar prediction ability, with a slight superiority of the BL confirming reports about the additive nature of rust resistance. When making predictions between environments and/or between populations, including information from another environment or environments or another population or populations improved prediction.

  9. Identification of wheat gene Sr35 that confers resistance to Ug99 stem rust race group.

    Science.gov (United States)

    Saintenac, Cyrille; Zhang, Wenjun; Salcedo, Andres; Rouse, Matthew N; Trick, Harold N; Akhunov, Eduard; Dubcovsky, Jorge

    2013-08-16

    Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is a devastating disease that can cause severe yield losses. A previously uncharacterized Pgt race, designated Ug99, has overcome most of the widely used resistance genes and is threatening major wheat production areas. Here, we demonstrate that the Sr35 gene from Triticum monococcum is a coiled-coil, nucleotide-binding, leucine-rich repeat gene that confers near immunity to Ug99 and related races. This gene is absent in the A-genome diploid donor and in polyploid wheat but is effective when transferred from T. monococcum to polyploid wheat. The cloning of Sr35 opens the door to the use of biotechnological approaches to control this devastating disease and to analyses of the molecular interactions that define the wheat-rust pathosystem.

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

    International Nuclear Information System (INIS)

    Koch, E.; Ebrahim-Nesbat, F.; Hoppe, H.H.

    1983-01-01

    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)

  11. First report of the white pine blister rust pathogen, Cronartium ribicola, in Arizona

    Science.gov (United States)

    M. L. Fairweather; Brian Geils

    2011-01-01

    White pine blister rust, caused by Cronartium ribicola J.C. Fisch., was found on southwestern white pine (Pinus flexilis James var. reflexa Engelm., synonym P. strobiformis Engelm.) near Hawley Lake, Arizona (Apache County, White Mountains, 34.024°N, 109.776°W, elevation 2,357 m) in April 2009. Although white pines in the Southwest (Arizona and New Mexico) have been...

  12. Molecular characterization of resistance to soybean rust (Phakopsora pachyrhizi Syd. & Syd.) in soybean cultivar DT 2000 (PI 635999)

    Science.gov (United States)

    Resistance to soybean rust (SBR), caused by Phakopsora pachyrhizi Syd.& Syd., has been identified in many soybean germplasm accessions and is conferred by either dominant or recessive genes that have been mapped to six independent loci (Rpp1 – Rpp6), but No U.S. cultivars are resistant to SBR. The c...

  13. Effect of partial resistance to barley leaf rust, Puccinia hordei, on the yield of three barley cultivars

    NARCIS (Netherlands)

    Ochoa, J.; Parlevliet, J.E.

    2007-01-01

    Three barley cultivars, Shyri, Clipper and Terán, with different levels of partial resistance to barley leaf rust, caused by Puccinia hordei, were exposed to six levels of the pathogen. These levels were obtained by 5, 4, 3, 2, 1 and 0 fungicide (Propiconazol) applications respectively and occurred

  14. Status of white pine blister rust and seed collections in california's high-elevation white pine species

    Science.gov (United States)

    J. Dunlap

    2011-01-01

    White pine blister rust (caused by the non-native pathogen Cronartium ribicola) reached northern California about 80 years ago. Over the years its spread southward had been primarily recorded on sugar pine. However, observations on its occurrence had also been reported in several of the higher elevation five-needled white pine species in California. Since the late...

  15. Identification and validation of single nucleotide polymorphic markers linked to Ug99 stem rust resistance in spring wheat

    Science.gov (United States)

    Wheat stem rust (Puccinia graminis f. sp. tritici Eriks. and E. Henn.) is one of the most destructive diseases world-wide. Races belonging to Ug99 (or TTKSK) continue to cause crop losses in East Africa and threaten global wheat production. Developing and deploying wheat varieties with multiple race...

  16. Molecular and cytogenetic characterization of a durum wheat Aegilops speltoides chromosome translocation conferring resistance to stem rust

    Science.gov (United States)

    Stem rust is a serious disease of wheat that has caused historical epidemics, but it has not been a threat in recent decades in North America due to the eradication of the alternate host and deployment of resistant cultivars. However, the recent emergence of Ug99 (or race TTKS) poses a threat to glo...

  17. A coordinated effort to manage soybean rust in North America: a success story in soybean disease monitoring

    Science.gov (United States)

    The anticipated threat of soybean rust (SBR), caused by the fungus Phakopsora pachyrhizi Sydow, resulted in an unprecedented effort to develop and implement disease monitoring and education platforms in North America. Since 2005, the primary platform for SBR information dispersal, known as the Soyb...

  18. Inhomogeneous Stripe Phase Revisited for Surface Superconductivity

    Science.gov (United States)

    Barzykin, Victor; Gor'kov, Lev P.

    2002-11-01

    We consider 2D surface superconductivity in high magnetic fields parallel to the surface. We demonstrate that the spin-orbit interaction at the surface changes the properties of the inhomogeneous superconducting Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) state that develops above fields given by the paramagnetic criterion. Strong spin-orbit interaction significantly broadens the range of existence of the LOFF phase, which takes the form of periodic superconducting stripes running along the field direction on the surface, leading to the anisotropy of its properties. Our results provide a tool for studying surface superconductivity as a function of doping.

  19. Tolerance of Loblolly Pines to Fusiform Rust

    Science.gov (United States)

    Charles H. Walkinshaw; James P. Barnett

    1995-01-01

    Loblolly pines (Pinus taeda L.) that were 8 to 17 yr old tolerated one to three fusiform rust (Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme) galls in their stems.Families with four or more galls in their stems lost 2.5% or more of the trees by age 17.In living trees with less than four stem galls, diameter growth was comparable to...

  20. Measurement Error Affects Risk Estimates for Recruitment to the Hudson River Stock of Striped Bass

    Directory of Open Access Journals (Sweden)

    Dennis J. Dunning

    2002-01-01

    Full Text Available We examined the consequences of ignoring the distinction between measurement error and natural variability in an assessment of risk to the Hudson River stock of striped bass posed by entrainment at the Bowline Point, Indian Point, and Roseton power plants. Risk was defined as the probability that recruitment of age-1+ striped bass would decline by 80% or more, relative to the equilibrium value, at least once during the time periods examined (1, 5, 10, and 15 years. Measurement error, estimated using two abundance indices from independent beach seine surveys conducted on the Hudson River, accounted for 50% of the variability in one index and 56% of the variability in the other. If a measurement error of 50% was ignored and all of the variability in abundance was attributed to natural causes, the risk that recruitment of age-1+ striped bass would decline by 80% or more after 15 years was 0.308 at the current level of entrainment mortality (11%. However, the risk decreased almost tenfold (0.032 if a measurement error of 50% was considered. The change in risk attributable to decreasing the entrainment mortality rate from 11 to 0% was very small (0.009 and similar in magnitude to the change in risk associated with an action proposed in Amendment #5 to the Interstate Fishery Management Plan for Atlantic striped bass (0.006— an increase in the instantaneous fishing mortality rate from 0.33 to 0.4. The proposed increase in fishing mortality was not considered an adverse environmental impact, which suggests that potentially costly efforts to reduce entrainment mortality on the Hudson River stock of striped bass are not warranted.

  1. A new 2DS·2RL Robertsonian translocation transfers stem rust resistance gene Sr59 into wheat.

    Science.gov (United States)

    Rahmatov, Mahbubjon; Rouse, Matthew N; Nirmala, Jayaveeramuthu; Danilova, Tatiana; Friebe, Bernd; Steffenson, Brian J; Johansson, Eva

    2016-07-01

    A new stem rust resistance gene Sr59 from Secale cereale was introgressed into wheat as a 2DS·2RL Robertsonian translocation. Emerging new races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici), from Africa threaten global wheat (Triticum aestivum L.) production. To broaden the resistance spectrum of wheat to these widely virulent African races, additional resistance genes must be identified from all possible gene pools. From the screening of a collection of wheat-rye (Secale cereale L.) chromosome substitution lines developed at the Swedish University of Agricultural Sciences, we described the line 'SLU238' 2R (2D) as possessing resistance to many races of P. graminis f. sp. tritici, including the widely virulent race TTKSK (isolate synonym Ug99) from Africa. The breakage-fusion mechanism of univalent chromosomes was used to produce a new Robertsonian translocation: T2DS·2RL. Molecular marker analysis and stem rust seedling assays at multiple generations confirmed that the stem rust resistance from 'SLU238' is present on the rye chromosome arm 2RL. Line TA5094 (#101) was derived from 'SLU238' and was found to be homozygous for the T2DS·2RL translocation. The stem rust resistance gene on chromosome 2RL arm was designated as Sr59. Although introgressions of rye chromosome arms into wheat have most often been facilitated by irradiation, this study highlights the utility of the breakage-fusion mechanism for rye chromatin introgression. Sr59 provides an additional asset for wheat improvement to mitigate yield losses caused by stem rust.

  2. 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...

  3. Coprecipitation of Arsenate and Arsenite with Green Rust Minerals

    Science.gov (United States)

    The objectives of this experiment were to evaluate the extent and nature of arsenic co-precipitation with green rusts and to examine the influence of arsenic incorporation on the mineralogy of formed solid phases. Stoichiometric green rusts were obtained by coprecipitation of fe...

  4. Progress on introduction of rust resistance genes into confection sunflower

    Science.gov (United States)

    Sunflower rust (Puccinia helianthi) emerged as a serious disease in the last few years. Confection sunflower is particularly vulnerable to the disease due to the lack of resistance sources. The objectives of this project are to transfer rust resistance genes from oil sunflower to confectionery sunfl...

  5. development of wheat germplasm for stem rust resistance in eastern ...

    African Journals Online (AJOL)

    ACSS

    especially of the virulent stem rust (Puccinia graminis) race, Ug99. The objective of this study was to identify sources of resistance to the major pathotypes of stem rust prevalent in some countries of Eastern Africa. Three hundred and six elite breeding lines, selected and advanced at the Wheat Regional Centre of Excellence ...

  6. Characterization of stem rust resistance gene Sr2 in Indian wheat ...

    African Journals Online (AJOL)

    Stem rust or black rust is one of the most important diseases of wheat worldwide. In India, central, peninsular and southern hill zones are particularly prone to stem rust where favourable environmental conditions exist. The recent emergence of wheat stem rust race Ug99 (TTKSK) and related strains threatens global wheat ...

  7. Competing States in the t-J Model: Uniform d-Wave State versus Stripe State versus Stripe State

    NARCIS (Netherlands)

    Corboz, P.R.; Rice, T.M.; Troyer, M.

    2014-01-01

    Variational studies of the t-J model on the square lattice based on infinite projected-entangled pair states confirm an extremely close competition between a uniform d-wave superconducting state and different stripe states. The site-centered stripe with an in-phase d-wave order has an equal or only

  8. Proteomic analysis of germinating urediniospores of Phakopsora pachyrhizi, causal agent of Asian soybean rust.

    Science.gov (United States)

    Luster, Douglas G; McMahon, Michael B; Carter, Melissa L; Fortis, Laurie L; Nuñez, Alberto

    2010-10-01

    Phakopsora pachyrhizi is an obligate pathogen that causes Asian soybean rust. Asian soybean rust has an unusually broad host range and infects by direct penetration through the leaf cuticle. In order to understand the early events in the infection process, it is important to identify and characterize proteins in P. pachyrhizi. Germination of the urediniospore is the first stage in the infection process and represents a critical life stage applicable to studies with this obligate pathogen. We have applied a 2-DE and MS approach to identify 117 proteins from the National Center of Biotechnology Information nonredundant protein database and a custom database of Basidiomycota EST sequences. Proteins with roles in primary metabolism, energy transduction, stress, cellular regulation and signaling were identified in this study. This data set is accessible at http://world-2dpage.expasy.org/repository/database=0018.

  9. Whitebark pine mortality related to white pine blister rust, mountain pine beetle outbreak, and water availability

    Science.gov (United States)

    Shanahan, Erin; Irvine, Kathryn M.; Thoma, David P.; Wilmoth, Siri K.; Ray, Andrew; Legg, Kristin; Shovic, Henry

    2016-01-01

    Whitebark pine (Pinus albicaulis) forests in the western United States have been adversely affected by an exotic pathogen (Cronartium ribicola, causal agent of white pine blister rust), insect outbreaks (Dendroctonus ponderosae, mountain pine beetle), and drought. We monitored individual trees from 2004 to 2013 and characterized stand-level biophysical conditions through a mountain pine beetle epidemic in the Greater Yellowstone Ecosystem. Specifically, we investigated associations between tree-level variables (duration and location of white pine blister rust infection, presence of mountain pine beetle, tree size, and potential interactions) with observations of individual whitebark pine tree mortality. Climate summaries indicated that cumulative growing degree days in years 2006–2008 likely contributed to a regionwide outbreak of mountain pine beetle prior to the observed peak in whitebark mortality in 2009. We show that larger whitebark pine trees were preferentially attacked and killed by mountain pine beetle and resulted in a regionwide shift to smaller size class trees. In addition, we found evidence that smaller size class trees with white pine blister rust infection experienced higher mortality than larger trees. This latter finding suggests that in the coming decades white pine blister rust may become the most probable cause of whitebark pine mortality. Our findings offered no evidence of an interactive effect of mountain pine beetle and white pine blister rust infection on whitebark pine mortality in the Greater Yellowstone Ecosystem. Interestingly, the probability of mortality was lower for larger trees attacked by mountain pine beetle in stands with higher evapotranspiration. Because evapotranspiration varies with climate and topoedaphic conditions across the region, we discuss the potential to use this improved understanding of biophysical influences on mortality to identify microrefugia that might contribute to successful whitebark pine conservation

  10. A green method of diaphragm spring's anti-rusting with high quality and efficiency

    Science.gov (United States)

    Huang, Xinming; Hua, Wenlin

    2017-10-01

    This paper introduces a green method of diaphragm spring's anti-rusting, which is of high quality, high efficiency and low consumption. It transforms the phosphating way of anti-rusting to physical anti-rusting that directly coat anti-rusting oil on the surface of the spring, and transforms the manual-oiling or oil-immersion to fully-automatically ultrasonic oiling. Hence, this method will completely change the way of diaphgragm spring's anti-rusting.

  11. 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.

  12. 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.

  13. 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. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  14. 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

  15. Evaluation of Genetic Diversity and Host Resistance to Stem Rust in USDA NSGC Durum Wheat Accessions.

    Science.gov (United States)

    Chao, Shiaoman; Rouse, Matthew N; Acevedo, Maricelis; Szabo-Hever, Agnes; Bockelman, Harold; Bonman, J Michael; Elias, Elias; Klindworth, Daryl; Xu, Steven

    2017-07-01

    The USDA-ARS National Small Grains Collection (NSGC) maintains germplasm representing global diversity of small grains and their wild relatives. To evaluate the utility of the NSGC durum wheat ( L. ssp. ) accessions, we assessed genetic diversity and linkage disequilibrium (LD) patterns in a durum core subset containing 429 lines with spring growth habit originating from 64 countries worldwide. Genetic diversity estimated using wheat single-nucleotide polymorphism (SNP) markers showed considerable diversity captured in this collection. Average LD decayed over a genetic distance to within 3 cM at = 0.2, with a fast LD decay for markers linked at >5 cM. We evaluated accessions for resistance to wheat stem rust, caused by a fungal pathogen, Pers. Pers. f. sp. Eriks. and E. Henn (), using races from both eastern Africa and North America, at seedling and adult plant stages. Five accessions were identified as resistant to all stem rust pathogen races evaluated. Genome-wide association analysis detected 17 significant associations at the seedling stage with nine likely corresponding to , , and and the remaining potentially being novel genes located on six chromosomes. A higher frequency of resistant accessions was found at the adult plant stage than at the seedling stage. However, few significant associations were detected possibly a result of strong G × E interactions not properly accounted for in the mixed model. Nonetheless, the resistant accessions identified in this study should provide wheat breeders with valuable resources for improving stem rust resistance. Copyright © 2017 Crop Science Society of America.

  16. White pine blister rust resistance in limber pine: evidence for a major gene.

    Science.gov (United States)

    Schoettle, A W; Sniezko, R A; Kegley, A; Burns, K S

    2014-02-01

    Limber pine (Pinus flexilis) is being threatened by the lethal disease white pine blister rust caused by the non-native pathogen Cronartium ribicola. The types and frequencies of genetic resistance to the rust will likely determine the potential success of restoration or proactive measures. These first extensive inoculation trials using individual tree seed collections from >100 limber pine trees confirm that genetic segregation of a stem symptom-free trait to blister rust is consistent with inheritance by a single dominant resistance (R) gene, and the resistance allele appears to be distinct from the R allele in western white pine. Following previous conventions, we are naming the R gene for limber pine "Cr4." The frequency of the Cr4 allele across healthy and recently invaded populations in the Southern Rocky Mountains was unexpectedly high (5.0%, ranging from 0 to 13.9%). Cr4 is in equilibrium, suggesting that it is not a product of a recent mutation and may have other adaptive significance within the species, possibly related to other abiotic or biotic stress factors. The identification of Cr4 in native populations of limber pine early in the invasion progress in this region provides useful information for predicting near-term impacts and structuring long-term management strategies.

  17. 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.

  18. FLUXAPYROXAD IN THE ASIAN SOYBEAN RUST CONTROL IN THE CERRADO BIOME

    Directory of Open Access Journals (Sweden)

    RAFAEL MENEZES SILVA DE FREITAS

    2016-01-01

    Full Text Available The etiologic agent of the Asian soybean rust is the Phakopsora pachyrhizi, which causes a reduction in the photosynthetic leaf area and, consequently, in the crop yield. Chemical control is one of the main measures for its management. The objective of this work was to evaluate the efficacy and selectivity of the fluxapyroxad fungicide on controlling the Asian soybean rust, under the edaphoclimatic conditions of the Cerrado biome. The experiment was conducted in an area under no-tillage system, in the Agricultural Research Center, Rio Verde, Goias, Brazil, during the 2012/2013 crop season, using the cultivar NA7337. A randomized block experimental design was used, with twelve treatments and four replications. The treatments consisted of applications of fluxapyroxad (FX, pyraclostrobin (PT, epoxiconazole (EX and metconazole (MZ. The average severity of the disease in the plants reached 37% in the Control. All treatments with fungicides differed from the Control. Treatments 9, 10, 11 and 12 provided the greatest rates of soybean rust control. The treatments 10, 11 and 12 had the highest thousand grain weights, and the yields of the treatments 2, 3 and 11, despite higher than the Control, were lower than the treatments 4, 5, 6, 7, 8, 9, 10 and 12, which had statistically equal yields. The increasing in yield, compared to the Control, ranged from 10.05% (pyraclostrobin, epoxiconazole + pyraclostrobin + mineral oil to 30.55% (pyraclostrobin, pyraclostrobin + fluxapyroxad + mineral oil and pyraclostrobin + metconazole + mineral oil. The highest rates of soybean rust control were presented by fungicides containing fluxapyroxad.

  19. Genome-wide association study of stem rust resistance in a world collection of cultivated barley.

    Science.gov (United States)

    Case, Austin J; Bhavani, Sridhar; Macharia, Godwin; Steffenson, Brian J

    2018-01-01

    QTL conferring a 14-40% reduction in adult plant stem rust severity to multiple races of Pgt were found on chromosome 5H and will be useful in barley breeding. Stem rust, caused by Puccinia graminis f. sp. tritici (Pgt) is an important disease of barley. The resistance gene Rpg1 has protected the crop against stem rust losses for over 70 years in North America, but is not effective against the African Pgt race TTKSK (and its variants) nor the domestic race QCCJB. To identify resistance to these Rpg1-virulent races, the Barley iCore Collection, held by the United States Department of Agriculture-Agricultural Research Service National Small Grains Collection was evaluated for adult plant resistance (APR) and seedling resistance to race TTKSK and APR to race QCCJB and the Pgt TTKSK composite of races TTKSK, TTKST, TTKTK, and TTKTT. Using a genome-wide association study approach based on 6224 single nucleotide polymorphic markers, seven significant loci for stem rust resistance were identified on chromosomes 1H, 2H, 3H, and 5H. The most significant markers detected were 11_11355 and SCRI_RS_177017 at 71-75 cM on chromosome 5H, conferring APR to QCCJB and TTKSK composite. Significant markers were also detected for TTKSK seedling resistance on chromosome 5H. All markers detected on 5H were independent of the rpg4/Rpg5 complex at 152-168 cM. This study verified the importance of the 11_11355 locus in conferring APR to races QCCJB and TTKSK and suggests that it may be effective against other races in the Ug99 lineage.

  20. Host specificity and genetic differentiation of Melampsora epitea (rust on willows)

    Energy Technology Data Exchange (ETDEWEB)

    Hurtado Pasten, Sergio [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Plant Pathology and Biocontrol Unit

    2001-07-01

    Rust caused by Melampsora epitea is considered the most serious and widespread disease on willows. When severe, rust can defoliate willows prematurely leading to serious yield losses and rootstock death. Studying the infection process, we found that M. epitea requires no specific recognition signals to germinate, grow, or penetrate the host stomata, regardless of whether interaction with the host plant is compatible or incompatible; instead, plant defense mechanisms are determined by substomatal events. Isolates of the Swedish rust population were classified (pathotyped) by their virulence patterns on a standard set of willow clones (willow differential). Thirty-seven pathotypes of M. epitea were identified and grouped into three formae speciales. For global monitoring of the virulence of M. epitea, an internationally useful naming system was proposed. Partly to confirm the value of such a naming system, the pathotype compositions of two distant M. epitea populations (from Sweden and Chile) were compared using the willow differential. The results indicated that long-distance inocula exchange likely plays an active role in the population dynamics and evolution of pathotype structure for M. epitea. To study the genetics underlying pathotype dynamics, molecular tools, such as AFLP, were used. The resulting dendrogram revealed no clustering based on geographic origin, and because geographic distance among pathogen populations correlated poorly with genetic distance, apparently geographically distant populations have developed collectively as a metapopulation instead of separately. However, the result shows that M. epitea has high levels of gene and genotypic variation within populations, which is consistent with the occurrence of sexual reproduction. The low between-population variation, despite variation in local selection pressures, accords with massive long-distance migration of rust spores.

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

    International Nuclear Information System (INIS)

    Makambila, C.

    1997-01-01

    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 LD 50 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

  2. Incorporation of Monovalent Cations in Sulfate Green Rust

    DEFF Research Database (Denmark)

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

    2014-01-01

    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......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...

  3. TaMAPK4 Acts as a Positive Regulator in Defense of Wheat Stripe-Rust Infection

    OpenAIRE

    Bing Wang; Na Song; Qiong Zhang; Ning Wang; Zhensheng Kang

    2018-01-01

    Highly conserved mitogen-activated protein kinase (MAPK) cascades regulate numerous plant processes, including hormonal responses, stress, and innate immunity. In this research, TaMAPK4 was predicted to be a target of tae-miR164. We verified the binding and suppression of TaMAPK4 by co-expression in Nicotiana benthamiana. Moreover, we found TaMAPK4 was localized in the cytoplasm and nucleus using transient expression analyses. TaMAPK4 transcripts increased following salicylic acid (SA) treatm...

  4. Characterization of a wheat HSP70 gene and its expression in response to stripe rust infection and abiotic stresses

    NARCIS (Netherlands)

    Duan, Y.H.; Guo, J.; Ding, K.; Wang, S.J.; Zhang, H.; Dai, X.W.; Chen, Y.Y.; Govers, F.; Huang, L.L.; Kang, Z.S.

    2011-01-01

    Members of the family of 70-kD heat shock proteins (HSP70 s) play various stress-protective roles in plants. In this study, a wheat HSP70 gene was isolated from a suppression subtractive hybridization (SSH) cDNA library of wheat leaves infected by Puccinia striiformis f. sp. tritici. The gene, that

  5. Rust Formation Mechanism on Low Alloy Steels after Exposure Test in High Cl− and High SOx Environment

    Science.gov (United States)

    Nishimura, Toshiyasu

    2017-01-01

    Exposure tests were performed on low alloy steels in high Cl− and high SOx environment, and the structure of the rust were analyzed by TEM (Transmission Electron Microscopy) and Raman Spectroscopy. In the exposure test site, the concentrations of Cl− and SOx were found to be high, which caused the corrosion of the steels. The conventional weathering steel (SMA: 0.6% Cr-0.4% Cu-Fe) showed higher corrosion resistance as compared to the carbon steel (SM), and Ni bearing steel exhibited the highest one. Raman spectroscopy showed that the inner rust of Ni bearing steel was mainly composed of α-FeOOH and spinel oxides. On the other hand, SMA contained β- and γ-FeOOH in inner rust, which increased the corrosion. TEM showed that nano-scale complex iron oxides containing Ni or Cr were formed in the rust on the low alloy steels, which suppressed the corrosion of steels in high Cl− and high SOx environment. PMID:28772560

  6. Rust Formation Mechanism on Low Alloy Steels after Exposure Test in High Cl− and High SOx Environmen

    Directory of Open Access Journals (Sweden)

    Toshiyasu Nishimura

    2017-02-01

    Full Text Available Exposure tests were performed on low alloy steels in high Cl− and high SOx environment, and the structure of the rust were analyzed by TEM (Transmission Electron Microscopy and Raman Spectroscopy. In the exposure test site, the concentrations of Cl− and SOx were found to be high, which caused the corrosion of the steels. The conventional weathering steel (SMA: 0.6% Cr-0.4% Cu-Fe showed higher corrosion resistance as compared to the carbon steel (SM, and Ni bearing steel exhibited the highest one. Raman spectroscopy showed that the inner rust of Ni bearing steel was mainly composed of α-FeOOH and spinel oxides. On the other hand, SMA contained β- and γ-FeOOH in inner rust, which increased the corrosion. TEM showed that nano-scale complex iron oxides containing Ni or Cr were formed in the rust on the low alloy steels, which suppressed the corrosion of steels in high Cl− and high SOx environment.

  7. Rust Formation Mechanism on Low Alloy Steels after Exposure Test in High Cl- and High SOx Environmen.

    Science.gov (United States)

    Nishimura, Toshiyasu

    2017-02-17

    Exposure tests were performed on low alloy steels in high Cl- and high SOx environment, and the structure of the rust were analyzed by TEM (Transmission Electron Microscopy) and Raman Spectroscopy. In the exposure test site, the concentrations of Cl- and SOx were found to be high, which caused the corrosion of the steels. The conventional weathering steel (SMA: 0.6% Cr-0.4% Cu-Fe) showed higher corrosion resistance as compared to the carbon steel (SM), and Ni bearing steel exhibited the highest one. Raman spectroscopy showed that the inner rust of Ni bearing steel was mainly composed of α-FeOOH and spinel oxides. On the other hand, SMA contained β- and γ-FeOOH in inner rust, which increased the corrosion. TEM showed that nano-scale complex iron oxides containing Ni or Cr were formed in the rust on the low alloy steels, which suppressed the corrosion of steels in high Cl- and high SOx environment.

  8. Identification of genes involved in stem rust resistance from wheat mutant D51 with the cDNA-AFLP technique.

    Science.gov (United States)

    Yin, Jing; Wang, Guangjin; Xiao, Jialei; Ma, Fengming; Zhang, Hongji; Sun, Yan; Diao, Yanling; Huang, Jinghua; Guo, Qiang; Liu, Dongjun

    2010-02-01

    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 was derived from the highly susceptible cultivar L6239, shows resistance to the prevailing races 21C3CPH, 21C3CKH, and 21C3CTR of P. graminis f. sp. tritici in China. In this study, we used the cDNA-AFLP technology to identify the genes that are likely involved in the stem rust resistance. EcoRI/MseI selective primers were used to generate approximately 1920 DNA fragments. Seventy five differentially transcribed fragments (3.91%) were identified by comparing the samples of 21C3CPH infected D51 with infected L6239 or uninfected D51. Eleven amplified cDNA fragments were sequenced. Eight showed significant similarity to known genes, including TaLr1 (leaf rust resistance gene), wlm24 (wheat powdery mildew resistance gene), stress response genes and ESTs of environment stress of tall fescue. These identified genes are involved in plant defense response and stem rust resistance and need further research to determine their usefulness in breeding new resistance cultivars.

  9. 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.

  10. A Small Cysteine-Rich Protein from the Asian Soybean Rust Fungus, Phakopsora pachyrhizi, Suppresses Plant Immunity.

    Directory of Open Access Journals (Sweden)

    Mingsheng Qi

    2016-09-01

    Full Text Available The Asian soybean rust fungus, Phakopsora pachyrhizi, is an obligate biotrophic pathogen causing severe soybean disease epidemics. Molecular mechanisms by which P. pachyrhizi and other rust fungi interact with their host plants are poorly understood. The genomes of all rust fungi encode many small, secreted cysteine-rich proteins (SSCRP. While these proteins are thought to function within the host, their roles are completely unknown. Here, we present the characterization of P. pachyrhizi effector candidate 23 (PpEC23, a SSCRP that we show to suppress plant immunity. Furthermore, we show that PpEC23 interacts with soybean transcription factor GmSPL12l and that soybean plants in which GmSPL12l is silenced have constitutively active immunity, thereby identifying GmSPL12l as a negative regulator of soybean defenses. Collectively, our data present evidence for a virulence function of a rust SSCRP and suggest that PpEC23 is able to suppress soybean immune responses and physically interact with soybean transcription factor GmSPL12l, a negative immune regulator.

  11. A Small Cysteine-Rich Protein from the Asian Soybean Rust Fungus, Phakopsora pachyrhizi, Suppresses Plant Immunity.

    Science.gov (United States)

    Qi, Mingsheng; Link, Tobias I; Müller, Manuel; Hirschburger, Daniela; Pudake, Ramesh N; Pedley, Kerry F; Braun, Edward; Voegele, Ralf T; Baum, Thomas J; Whitham, Steven A

    2016-09-01

    The Asian soybean rust fungus, Phakopsora pachyrhizi, is an obligate biotrophic pathogen causing severe soybean disease epidemics. Molecular mechanisms by which P. pachyrhizi and other rust fungi interact with their host plants are poorly understood. The genomes of all rust fungi encode many small, secreted cysteine-rich proteins (SSCRP). While these proteins are thought to function within the host, their roles are completely unknown. Here, we present the characterization of P. pachyrhizi effector candidate 23 (PpEC23), a SSCRP that we show to suppress plant immunity. Furthermore, we show that PpEC23 interacts with soybean transcription factor GmSPL12l and that soybean plants in which GmSPL12l is silenced have constitutively active immunity, thereby identifying GmSPL12l as a negative regulator of soybean defenses. Collectively, our data present evidence for a virulence function of a rust SSCRP and suggest that PpEC23 is able to suppress soybean immune responses and physically interact with soybean transcription factor GmSPL12l, a negative immune regulator.

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

    International Nuclear Information System (INIS)

    Khan, M.A.; Haider, M.M.; Hussain, M.; Ahmad, S.

    2007-01-01

    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

  13. Stripe order from the perspective of the Hubbard model

    Energy Technology Data Exchange (ETDEWEB)

    Devereaux, Thomas Peter

    2018-03-01

    A microscopic understanding of the strongly correlated physics of the cuprates must account for the translational and rotational symmetry breaking that is present across all cuprate families, commonly in the form of stripes. Here we investigate emergence of stripes in the Hubbard model, a minimal model believed to be relevant to the cuprate superconductors, using determinant quantum Monte Carlo (DQMC) simulations at finite temperatures and density matrix renormalization group (DMRG) ground state calculations. By varying temperature, doping, and model parameters, we characterize the extent of stripes throughout the phase diagram of the Hubbard model. Our results show that including the often neglected next-nearest-neighbor hopping leads to the absence of spin incommensurability upon electron-doping and nearly half-filled stripes upon hole-doping. The similarities of these findings to experimental results on both electron and hole-doped cuprate families support a unified description across a large portion of the cuprate phase diagram.

  14. 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

  15. Pathological changes associated with white striping in broiler breast muscles.

    Science.gov (United States)

    Kuttappan, V A; Shivaprasad, H L; Shaw, D P; Valentine, B A; Hargis, B M; Clark, F D; McKee, S R; Owens, C M

    2013-02-01

    White striping is a condition in broiler chickens characterized grossly by the occurrence of white striations, seen parallel to the direction of muscle fibers, on broiler breast fillets and thighs. Based on visual evaluation of the intensity of white striping, breast fillets can be categorized into normal (NORM), moderate (MOD), and severe (SEV) categories. This study was undertaken to evaluate the details of changes in histology as well as proximate composition occurring in the fillets with respect to the 3 degrees of white striping. In experiment 1, representative breast fillets for each degree of white striping (n = 20) were collected from 45-d-old broilers, approximately 2 h postmortem. From each fillet, 2 skeletal muscle samples were obtained and fixed in 10% neutral buffered formalin. To identify and differentiate the histological changes, slides were prepared and stained using hematoxylin and eosin, Masson's Trichrome, and Oil Red O stains. In experiment 2, samples with 3 degrees of white striping were collected from 57-d-old birds for conducting proximate analysis. Major histopathological changes observed in the MOD and SEV samples consisted of loss of cross striations, variability in fiber size, floccular/vacuolar degeneration and lysis of fibers, mild mineralization, occasional regeneration (nuclear rowing and multinucleated cells), mononuclear cell infiltration, lipidosis, and interstitial inflammation and fibrosis. Microscopic lesions were visually scored for degeneration and necrosis, fibrosis, and lipidosis. The scale used to score the samples ranged from 0 (normal) to 3 (severe). There was an increase (P white striping increased from NORM to SEV. The results from the histopathological study were supported by the findings from proximate analysis confirming that the fat and protein contents of muscle increased (P white striping increased. In conclusion, the histopathological changes occurring in white striping indicate a degenerative myopathy that

  16. 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.

  17. Tiger Stripes and Cassini ISS High-Resolution Imaging of Enceladus

    Science.gov (United States)

    Helfenstein, Paul; Denk, T.; Giese, B.; McEwen, A. S.; Neukum, G.; Perry, J.; Porco, C. C.; Thomas, P. C.; Turtle, E.; Verbiscer, A.; Veverka, J.

    2008-09-01

    Deciphering the mechanisms of Enceladus’ plumes is one of the most important and challenging tasks for planetary science. Cassini has provided a wealth of data by remote and in-situ data collection, but fundamental details of the vents and their context remain elusive. Three flybys of Enceladus by Cassini in 2008, on August 11 (altitude: 50km), October 9 (30km), and October 31 (200 km) are designed to further our knowledge of Enceladus’ geology and geophysics. Anticipated data include images as good as 7 m/pixel of parts of the geologically active South Polar Terrain (SPT). We targeted six different known eruption sites (Spitale and Porco 2007, Nature 449, 695-697) along Cairo Sulcus, Baghdad Suclus, and Damascus Sulcus, as well as non-active portions of the the "tiger stripes" and bright grooved terrain in between. On each of the three flybys we also plan contiguous ISS broadband multi-spectral mosaics of the entire SPT region so that we can search for volcanically and tectonically driven temporal changes and construct detailed digital terrain maps. Previous images of the tiger stripes and other rift systems on Enceladus resolve geomorphic structures on hundred meter scales or larger. Within those resolution limits, tiger stripes are morphologically distinguished most strongly from comparably sized young looking rifts elsewhere on Enceladus by their prominent upturned flanks, the muted appearance of their surface relief, and their relative absence of distinct cliff faces, probably of solid ice along scarps. The anticipated new high-resolution images will provide critical structural details needed to identify the extent to which unique attributes of tiger stripes are caused by mantling by plume fallout, tectonic deformation, seismic disruption, or perhaps thermal processes. Here, we present a first analysis of the August 11 close flyby images.

  18. Sustained eruptions on Enceladus explained by turbulent dissipation in tiger stripes

    Science.gov (United States)

    Kite, Edwin S.; Rubin, Allan M.

    2016-04-01

    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 eruptions from “tiger stripe” fissures that are sustained (although tidally modulated) throughout each orbit, and since the 2005 discovery of the plumes. Peak plume flux lags peak tidal extension by ˜1 rad, 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 eruptions are maintained over geological timescales. The delay associated with flushing and refilling of 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 slot freezeout. Much narrower and much wider slots cannot be sustained. In the presence of long-lived slots, the 106-y average power output of the tiger stripes is buffered by a feedback between ice melt-back and subsidence to O(1010) W, which is similar to observed power output, suggesting long-term stability. Turbulent dissipation makes testable predictions for the final flybys of Enceladus by Cassini. Our model shows how open connections to an ocean can be reconciled with, and sustain, long-lived eruptions. Turbulent dissipation in long-lived slots helps maintain the ocean against freezing, maintains access by future Enceladus missions to ocean materials, and is plausibly the major energy source for tiger stripe activity.

  19. A mutagenesis-derived broad-spectrum disease resistance locus in wheat

    Science.gov (United States)

    Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. The most effective and widely uti...

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

    DEFF Research Database (Denmark)

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

    an integrated set of datasets on both pathogen and host at the global scale. The Global Cereal Rust Monitoring System (GCRMS), created under the Durable Rust resistance in Wheat (DRRW) project, represents a unique and increasingly comprehensive resource of rust information. A suite of tools are now available....... Integration of the CIMMYT Wheat Atlas and the Genetic Resources Information System (GRIS) databases provides a rich resource on wheat cultivars and their resistance to important rust races. Data access is facilitated via dedicated web portals such as Rust Tracker (www.rusttracker.org) and the Global Rust...

  1. Efeito de indutores bióticos e abióticos na atividade de quitinase e peroxidase e no controle da ferrugem causada por Puccinia psidii em eucalipto Effect of biotic and abiotic inducers on the activities of chitinase and peroxidase and rust control caused by Puccinia psidii on Eucalyptus

    Directory of Open Access Journals (Sweden)

    Leonardo Pires Boava

    2010-06-01

    Full Text Available Verificou-se o efeito de indutores de resistência bióticos e abióticos nas atividades de quitinase e peroxidase e na redução da severidade da ferrugem do eucalipto causada por Puccinia psidii. Para isso, mudas de dois clones de eucalipto (Eucalyptus grandis x E. urophylla denominados VR e C0, com sessenta dias de idade, mantidas em casa de vegetação, receberam tratamentos com Bion® (Acibenzolar-S-metil-ASM, Agro-Mos®, Dipel®, Ecolife40®, Crop-set® e uma preparação obtida a partir de Saccharomyces cerevisiae, 5 dias antes da inoculação com o patógeno. Uma suspensão de uredósporos de P. psidii, coletados a partir de plantas naturalmente infectadas, foi calibrada para 5 x 10(4 uredósporos/ mL. A inoculação foi realizada na face abaxial das folhas e a avaliação se deu 15 dias após, estimando-se a severidade da doença por meio de escala de notas. Os tratamentos ASM, preparado de S. cerevisiae e Ecolife® apresentaram os melhores resultados de controle da doença e os demais tratamentos não se mostraram eficazes para o controle. O aumento de atividade das enzimas quitinase e peroxidase foi observado em ambos os clones, previamente tratados com os indutores(ASM e S. cerevisiae, 48 horas após a inoculação com o fungo.This study was aimed at verifying the effect of biotic and abiotic resistance inducers on the activities of chitinase and peroxidase as well as on the reduction of rust caused by Puccinia psidii in eucalyptus. Thus, seedlings of two 60-day eucalyptus clones were kept in a greenhouse and treated with Bion® (Acibenzolar-S-methyl, ASM, Agro-Mos®, Saccharomyces cerevisiae, Dipel®, Ecolife 40®, and Crop-set®, at 5 days before the pathogen inoculation. A suspension of P. psidii uredospores, collected from naturally infected plants, was adjusted to 5 x 10(4 uredospores/mL. Inoculation was carried out onto the dorsal leaf surface and 15 days later the disease severity was assessed according to a grading scale. ASM

  2. Identification of new resistance loci to African stem rust race TTKSK in tetraploid wheats based on linkage and genome-wide association mapping

    Directory of Open Access Journals (Sweden)

    Giovanni eLaidò

    2015-12-01

    Full Text Available Stem rust, caused by Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn. (Pgt, is one of the most destructive diseases of wheat. Races of the pathogen in the Ug99 lineage are of international concern due to their virulence for widely used stem rust resistance genes and their spread throughout Africa. Disease resistant cultivars provide one of the best means for controlling stem rust. To identify quantitative trait loci (QTL conferring resistance to African stem rust race TTKSK at the seedling stage, we evaluated an association mapping (AM panel consisting of 230 tetraploid wheat accessions under greenhouse conditions. A high level of phenotypic variation was observed in response to race TTKSK in the AM panel, allowing for genome-wide association mapping of resistance QTL in wild, landrace, and cultivated tetraploid wheats. Thirty-five resistance QTL were identified on all chromosomes, and seventeen are of particular interest as identified by multiple associations. Many of the identified resistance loci were coincident with previously identified rust resistance genes; however, nine on chromosomes 1AL, 2AL, 4AL, 5BL and 7BS may be novel. To validate AM results, a biparental population of 146 recombinant inbred lines was also considered, which derived from a cross between the resistant

  3. Mapping of Leaf Rust Resistance Genes and Molecular Characterization of the 2NS/2AS Translocation in the Wheat Cultivar Jagger.

    Science.gov (United States)

    Xue, Shulin; Kolmer, James A; Wang, Shuwen; Yan, Liuling

    2018-04-19

    Winter wheat cultivar 'Jagger' was recently found to have an alien chromosomal segment 2NS that has Lr37 , a gene conferring resistance against leaf rust caused by Puccinia triticina The objective of this study was to map and characterize the gene(s) for seedling leaf rust resistance in Jagger. The recombinant inbred line (RIL) population of Jagger × '2174' was inoculated with leaf rust pathogen THBJG and BBBDB, and evaluated for infection type (IT) response. A major quantitative trait locus (QTL) for THBJG and BBBDB was coincidently mapped to chromosome arm 2AS, and the QTL accounted for 56.6% - 66.2% of total phenotypic variation in infection type (IT) response to THBJG, and 72.1% - 86.9% to BBBDB. The causal gene for resistance to these rust races was mapped to the 2NS segment in Jagger. The 2NS segment was located in a region of approximately 27.8 Mb starting from the telomere of chromosome arm 2AS, based on the sequences of the A genome in tetraploid wheat. The Lr17a gene on chromosome arm 2AS was delimited to 3.1 Mb in the genomic region, which was orthologous to the 2NS segment. Therefore, the Lr37 gene in the 2NS segment can be pyramided with other effective resistance genes, rather than Lr17a in wheat, to improve resistance to rust diseases. Copyright © 2018, G3: Genes, Genomes, Genetics.

  4. Concerted action of two avirulent spore effectors activates Reaction to Puccinia graminis 1 (Rpg1)-mediated cereal stem rust resistance.

    Science.gov (United States)

    Nirmala, Jayaveeramuthu; Drader, Tom; Lawrence, Paulraj K; Yin, Chuntao; Hulbert, Scot; Steber, Camille M; Steffenson, Brian J; Szabo, Les J; von Wettstein, Diter; Kleinhofs, Andris

    2011-08-30

    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 within 5 min and subsequently degraded. Application of arginine-glycine-aspartic acid peptide loops prevented the formation of adhesion structures for spore attachment, the phosphorylation of RPG1, and germination of the viable spores. Arginine-glycine-aspartic acid affinity chromatography of proteins from the ungerminated avirulent rust spores led to the purification and identification of a protein with fibronectin type III and breast cancer type 1 susceptibility protein domains and a vacuolar protein sorting-associated protein 9 with a coupling of ubiquitin to endoplasmic reticulum degradation domain. Both proteins are required to induce in vivo phosphorylation and degradation of RPG1. Combined application of both proteins caused hypersensitive reaction on the stem rust-resistant cultivar Morex but not on the susceptible cultivar Steptoe. Expression studies indicated that mRNA of both genes are present in ungerminated urediniospores and are constitutively transcribed in sporelings, infected leaves, and haustoria in the investigated avirulent races. Evidence is presented that RPG1, in yeast, interacts with the two protein effectors from the urediniospores that activate cooperatively the stem rust resistance protein RPG1 long before haustoria formation.

  5. Complementary epistasis involving Sr12 explains adult plant resistance to stem rust in Thatcher wheat (Triticum aestivum L.).

    Science.gov (United States)

    Rouse, Matthew N; Talbert, Luther E; Singh, Davinder; Sherman, Jamie D

    2014-07-01

    Quantitative trait loci conferring adult plant resistance to Ug99 stem rust in Thatcher wheat display complementary gene action suggesting multiple quantitative trait loci are needed for effective resistance. Adult plant resistance (APR) in wheat (Triticum aestivum L.) to stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is desirable because this resistance can be Pgt race non-specific. Resistance derived from cultivar Thatcher can confer high levels of APR to the virulent Pgt race TTKSK (Ug99) when combined with stem rust resistance gene Sr57 (Lr34). To identify the loci conferring APR in Thatcher, we evaluated 160 RILs derived from Thatcher crossed to susceptible cultivar McNeal for field stem rust reaction in Kenya for two seasons and in St. Paul for one season. All RILs and parents were susceptible as seedlings to race TTKSK. However, adult plant stem rust severities in Kenya varied from 5 to 80 %. Composite interval mapping identified four quantitative trait loci (QTL). Three QTL were inherited from Thatcher and one, Sr57, was inherited from McNeal. The markers closest to the QTL peaks were used in an ANOVA to determine the additive and epistatic effects. A QTL on 3BS was detected in all three environments and explained 27-35 % of the variation. The peak of this QTL was at the same location as the Sr12 seedling resistance gene effective to race SCCSC. Epistatic interactions were significant between Sr12 and QTL on chromosome arms 1AL and 2BS. Though Sr12 cosegregated with the largest effect QTL, lines with Sr12 were not always resistant. The data suggest that Sr12 or a linked gene, though not effective to race TTKSK alone, confers APR when combined with other resistance loci.

  6. Moessbauer Characterization of Rust Obtained in an Accelerated Corrosion Test

    International Nuclear Information System (INIS)

    Garcia, K. E.; Morales, A. L.; Arroyave, C. E.; Barrero, C. A.; Cook, D. C.

    2003-01-01

    We have performed drying-humectation cyclical processes (CEBELCOR) on eight A36 low carbon steel coupons in NaCl solutions containing 1x10 -2 M and 1x10 -1 M concentrations. The main purpose of these experiments is to contribute to the understanding of the conditions for akaganeite formation. Additionally, and with the idea to perform a complete characterization of the rust, this work also considers the formation of other iron oxide phases. The corrosion products were characterized by Moessbauer spectroscopy and X-ray diffraction techniques. Gravimetric analysis demonstrates that the coupons presented high corrosion rates. Magnetite/maghemite was common in the rust stuck to the steel surface, whereas akaganeite was present only in traces. In the rust collected from the solutions, i.e., the rust that goes away from the metal surface easily, a magnetite/maghemite was not present and akaganeite showed up in larger quantities. These results support the idea that high concentrations of Cl - ions are required for the akaganeite formation. We concluded that akaganeite is not easily bonded to the rust layer; this may lead to the formation of a less protective rust layer and to higher corrosion rates.

  7. 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). Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Millijansky radio variability in SDSS stripe 82

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, J. A.; Becker, R. H. [University of California, 1 Shields Avenue, Davis, CA 95616 (United States); White, R. L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Richards, G. T., E-mail: hodge@mpia.de [Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)

    2013-06-01

    We report on a blind survey for extragalactic radio variability that was carried out by comparing two epochs of data from the Faint Images of the Radio Sky at Twenty centimeters survey with a third epoch from a new 1.4 GHz survey of SDSS Stripe 82. The three epochs are spaced seven years apart and have an overlapping area of 60 deg{sup 2}. We uncover 89 variable sources down to the millijansky level, 75 of which are newly identified, and we find no evidence for transient phenomena. This new sample of variable sources allows us to infer an upper limit to the mean characteristic timescale of active galactic nucleus radio variability of 14 yr. We find that only 1% of extragalactic sources have fractional variability f {sub var} > 3, while 44% of Galactic sources vary by this much. The variable sample contains a larger fraction of quasars than a comparable non-variable control sample, though the majority of the variable sources appear to be extended galaxies in the optical. This implies that either quasars are not the dominant contributor to the variability of the sample, or that the deep optical data allow us to detect the host galaxies of some low-z quasars. We use the new, higher resolution data to report on the morphology of the variable sources. Finally, we show that the fraction of sources that are variable remains constant or increases at low flux densities. This may imply that next generation radio surveys with telescopes like Australian Square Kilometer Array Pathfinder and MeerKAT will see a constant or even increasing fraction of variable sources down into the sub-millijansky regime.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Hye; Choi, Jae boong; Kim, Moon Ki [Sungkyunkwan Univ., Seoul (Korea, Republic of); Huh, Nam Su [Seoul Nat' l Univ., Seoul (Korea, Republic of); Lee, Jin Ho [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2012-10-15

    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.

  10. Nuclear proteomic changes linked to soybean rust resistance.

    Science.gov (United States)

    Cooper, Bret; Campbell, Kimberly B; Feng, Jian; Garrett, Wesley M; Frederick, Reid

    2011-03-01

    Soybean rust, caused by the fungus Phakopsora pachyrhizi, is an emerging threat to the US soybean crop. In an effort to identify proteins that contribute to disease resistance in soybean we compared a susceptible Williams 82 cultivar to a resistant Williams 82 inbred isoline harboring the Rpp1 resistance gene (R-gene). Approximately 4975 proteins from nuclear preparations of leaves were detected using a high-throughput liquid chromatography-mass spectrometry method. Many of these proteins have predicted nuclear localization signals, have homology to transcription factors and other nuclear regulatory proteins, and are phosphorylated. Statistics of summed spectral counts revealed sets of proteins with differential accumulation changes between susceptible and resistant plants. These protein accumulation changes were compared to previously reported gene expression changes and very little overlap was found. Thus, it appears that numerous proteins are post-translationally affected in the nucleus after infection. To our knowledge, this is the first indication of large-scale proteomic change in a plant nucleus after infection. Furthermore, the data reveal distinct proteins under control of Rpp1 and show that this disease resistance gene regulates nuclear protein accumulation. These regulated proteins likely influence broader defense responses, and these data may facilitate the development of plants with improved resistance.

  11. Winter wheat susceptibilty to leaf rust and resistance sources to diseases

    Directory of Open Access Journals (Sweden)

    Jerzy Chełkowski

    2012-12-01

    Full Text Available Winter wheat cultivars were significantly infected by Puccinia triticina causing leaf rust in seasons 2000-2002 in southern and also central regions of Poland. Resistance genes Lr9, Lr19 and Lr24 were found to be effective against dominating populations of the pathogen and typical isolates of P. triticina. Mentioned three resistance genes as well as genes Lr10 and Lr37 were identified using STS (Sequence Tagged Site DNA - PCR markers in cultivars and resistance sources. Mentioned markers were found very useful in resistance breeding of wheat.

  12. Diversifying selection in the wheat stem rust fungus acts predominantly on pathogen-associated gene families and reveals candidate effectors

    OpenAIRE

    Sperschneider, Jana; Ying, Hua; Dodds, Peter N.; Gardiner, Donald M.; Upadhyaya, Narayana M.; Singh, Karam B.; Manners, John M.; Taylor, Jennifer M.

    2014-01-01

    Plant pathogens cause severe losses to crop plants and threaten global food production. One striking example is the wheat stem rust fungus, Puccinia graminis f. sp. tritici, which can rapidly evolve new virulent pathotypes in response to resistant host lines. Like several other filamentous fungal and oomycete plant pathogens, its genome features expanded gene families that have been implicated in host-pathogen interactions, possibly encoding effector proteins that interact directly with targe...

  13. Genetic control of soybean (Glycine max) yield in the absence and presence of the Asian rust fungus (Phakopsora pachyrhizi)

    OpenAIRE

    Ribeiro, Aliny Simony; Toledo, José Francisco Ferraz de; Arias, Carlos Alberto Arrabal; Godoy, Cláudia Vieira; Soares, Rafael Moreira; Moreira, José Ubirajara Vieira; Pierozzi, Pedro Henrique Braga; Vidigal, Maria Celeste Gonçalves; Oliveira, Marcelo Fernandes de

    2008-01-01

    Soybean is one of the most important crops in Brazil and continuously generates demands for production technologies, such as cultivars resistant to diseases. In recent years, the Asian rust fungus (Phakopsora pachyrhizi Syd. & P. Syd 1914) has caused severe yield losses and the development of resistant cultivars is the best means of control. Understanding the genetic control and estimating parameters associated with soybean (Glycine max) resistance to P. pachyrhizi will provide essential ...

  14. De novo assembly and phasing of dikaryotic genomes from two isolates of Puccinia coronata f. sp. avenae, the causal agent of oat crown rust

    Science.gov (United States)

    Oat crown rust, caused by the fungus Puccinia coronata f. sp. avenae (Pca), is a devastating disease that impacts worldwide oat production. For much of its life cycle Pca is dikaryotic with two separate haploid nuclei that may vary in virulence genotypes, which highlights the importance of understan...

  15. De novo assembly and phasing of dikaryotic genomes from two isolates of Puccini coronata f. sp. avenae, the causal agent of oat crown rust

    Science.gov (United States)

    Marisa E. Miller; Ying Zhang; Vahid Omidvar; Jana Sperschneider; Benjamin Schwessinger; Castle Raley; Jonathan M. Palmer; Diana Garnica; Narayana Upadhyaya; John Rathjen; Jennifer M. Taylor; Robert F. Park; Peter N. Dodds; Cory D. Hirsch; Shahryar F. Kianian; Melania. Figueroa

    2018-01-01

    Oat crown rust, caused by the fungus Pucinnia coronata f. sp. avenae, is a devastating disease that impacts worldwide oat production. For much of its life cycle, P. coronata f. sp. avenae is dikaryotic, with two separate haploid nuclei that may vary in virulence genotype, highlighting...

  16. Genetic mapping of Pinus flexilis major gene (Cr4) for resistance to white pine blister rust using transcriptome-based SNP genotyping

    Science.gov (United States)

    Jun-Jun Liu; Anna W. Schoettle; Richard A. Sniezko; Rona N. Sturrock; Arezoo Zamany; Holly Williams; Amanda Ha; Danelle Chan; Bob Danchok; Douglas P. Savin; Angelia Kegley

    2016-01-01

    Linkage of DNA markers with phenotypic traits provides essential information to dissect clustered genes with potential phenotypic contributions in a target genome region. Pinus flexilis E. James (limber pine) is a keystone five-needle pine species in mountain-top ecosystems of North America. White pine blister rust (WPBR), caused by a non-native fungal...

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

    NARCIS (Netherlands)

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

    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

  18. First report of Phakopsora pachyrhizi adapting to soybean genotypes with Rpp1 or Rpp6 rust resistance genes in field plots in the United States

    Science.gov (United States)

    Since the first detection of soybean rust, caused by Phakopsora pachyrhizi Syd., in the continental United States in November, 2004, soybean [Glycine max (L.) Merr.] genotypes with the Rpp1 or Rpp6 resistance genes have exhibited high levels of resistance in the United States. In 2011 and 2012, howe...

  19. The effect of the 'Hyuuga' soybean lesion type and canopy severity on yield loss in the presence of soybean rust (Phakopsora pachyrhizi)

    Science.gov (United States)

    Soybean rust, caused by the fungal pathogen Phakopsora pachyrhizi, occurs in many areas of the world and is a destructive foliar disease. Susceptible soybean leaves exhibit a “TAN” reaction characterized by lesions with abundant urediniospores, while resistant reactions involve either an immune resp...

  20. From stripe to slab confinement for DNA linearization in nanochannels

    Science.gov (United States)

    Cifra, Peter; Benkova, Zuzana; Namer, Pavol

    We investigate suggested advantageous analysis in the linearization experiments with macromolecules confined in a stripe-like channel using Monte Carlo simulations. The enhanced chain extension in a stripe that is due to significant excluded volume interactions between monomers in two dimensions weakens on transition to experimentally feasible slit-like channel. Based on the chain extension-confinement strength dependence and the structure factor behavior for the chain in stripe we infer the excluded volume regime typical for two-dimensional systems. On transition to the slab geometry, the advantageous chain extension decreases and the Gaussian regime is observed for not very long semiflexible chains. The evidence for pseudo-ideality in confined chains is based on indicators such as the extension curves, variation of the extension with the persistence length or the structure factor. The slab behavior is observed when the stripe (originally of monomer thickness) reaches the thickness larger than cca 10nm in the third dimension. This maximum height of the slab to retain the advantage of the stripe is very low and this have implication for DNA linearization experiments. The presented analysis, however, has a broader relevance for confined polymers. Support from Slovak R&D Agency (SRDA-0451-11) is acknowledged.

  1. Legume breeding for rust resistance: Lessons to learn from the model Medicago truncatula

    OpenAIRE

    Rubiales, Diego; Castillejo Sánchez, M. Ángeles; Madrid, Eva; Barilli, Eleonora; Rispail, Nicolas

    2011-01-01

    Rusts are major biotic constraints of legumes worldwide. Breeding for rust resistance is regarded as the most cost efficient method for rust control. However, in contrast to common bean for which complete monogenic resistance exists and is efficiently used, most of the rust resistance reactions described so far in cool season food legumes are incomplete and of complex inheritance. Incomplete resistance has been described in faba bean, pea, chickpea and lentil and several of their associated Q...

  2. 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 ...

  3. Markers Linked to Wheat Stem Rust Resistance Gene Sr11 Effective to Puccinia graminis f. sp. tritici Race TKTTF.

    Science.gov (United States)

    Nirmala, Jayaveeramuthu; Chao, Shiaoman; Olivera, Pablo; Babiker, Ebrahiem M; Abeyo, Bekele; Tadesse, Zerihun; Imtiaz, Muhammad; Talbert, Luther; Blake, Nancy K; Akhunov, Eduard; Pumphrey, Michael O; Jin, Yue; Rouse, Matthew N

    2016-11-01

    Wheat stem rust, caused by Puccinia graminis f. sp. tritici, can cause severe yield losses on susceptible wheat varieties and cultivars. Although stem rust can be controlled by the use of genetic resistance, population dynamics of P. graminis f. sp. tritici can frequently lead to defeat of wheat stem rust resistance genes. P. graminis f. sp. tritici race TKTTF caused a severe epidemic in Ethiopia on Ug99-resistant 'Digalu' in 2013 and 2014. The gene Sr11 confers resistance to race TKTTF and is present in 'Gabo 56'. We identified seven single-nucleotide polymorphism (SNP) markers linked to Sr11 from a cross between Gabo 56 and 'Chinese Spring' exploiting a 90K Infinium iSelect Custom beadchip. Five SNP markers were validated on a 'Berkut'/'Scalavatis' population that segregated for Sr11, using KBioscience competitive allele-specific polymerase chain reaction (KASP) assays. Two of the SNP markers, KASP_6BL_IWB10724 and KASP_6BL_IWB72471, were predictive of Sr11 among wheat genetic stocks, cultivars, and breeding lines from North America, Ethiopia, and Pakistan. These markers can be utilized to select for Sr11 in wheat breeding and to detect the presence of Sr11 in uncharacterized germplasm.

  4. New Seeds are Resistant to Wheat Stem Rust (Ug99) Multinational Programme Supported by FAO and IAEA

    International Nuclear Information System (INIS)

    2013-01-01

    Full text: A multinational effort supported by the International Atomic Energy Agency and the U.N. Food and Agriculture Organization marked a key milestone this week when a Kenyan university debuted two new varieties of disease-resistant wheat to the nation's farmers. Over the past two days, thousands of Kenyan farmers have visited Eldoret University in western Kenya for a two-day agriculture fair highlighting the latest farming technologies. Supporting the development of the new varieties were the IAEA's Technical Cooperation Department and the Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture. They manage an interregional Technical Cooperation project to develop varieties of wheat that are resistant to a devastating type of fungus, causing a disease known as wheat stem rust. Wheat stem rust under control for over 30 years, but a resurgence of the disease was discovered in 1999 in Uganda that swiftly spread to neighbouring Kenya. The wheat stem rust, caused by the strain of the fungus known as Ug99, named after its place and year of origin, has since spread to Iran, Yemen and South Africa and threatens crops as far away as India as spores are carried by wind. Parasitic rusts threaten global wheat production, reducing plant growth and crop yields. The disease can destroy up to 70-100 percent of the yield of wheat crop if not prevented. 'Improving food security in developing countries through the use of nuclear techniques is an important priority of the IAEA', said IAEA Director General Yukiya Amano. 'I am pleased that we have been able to make an important contribution to fighting wheat rust'. 'Wheat rusts, particularly the Ug99 strain, are a major threat to food security because rust epidemics can result in devastating yield losses. This international project involving affected countries, plant scientists and breeders and international organizations is a major breakthrough. It clearly shows the benefits of FAO/IAEA collaboration and that

  5. Identification of leaf rust resistant gene Lr10 in Pakistani wheat ...

    African Journals Online (AJOL)

    Jane

    2011-08-10

    Aug 10, 2011 ... survey was conducted to screen 25 Pakistan wheat germplasm for the presence of leaf rust resistance gene Lr10 using specific STS primer. ... conducted on the life cycles of rust pathogens and their management. Due to airborne nature .... To date, more than 45 stem rust resistance Sr (genes) (McIntosh et ...

  6. Introgression of a leaf rust resistance gene from Aegilops caudata to ...

    Indian Academy of Sciences (India)

    Keywords. alien introgression; molecular mapping; leaf rust; Puccinia triticina; Triticum aestivum; Aegilops caudata. Abstract. 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 ...

  7. Aecidium kalanchoe sp. nov., a new rust on Kalanchoe blossfeldiana (Crassulaceae).

    Science.gov (United States)

    Hernádez, José R; Aime, M Catherine; Newbry, Brad

    2004-07-01

    A rust fungus found on cultivars of Kalanchoe blossfeldiana (Crassulaceae) is described as a new species, Aecidium kalanchoe sp. nov., and compared to the other described rusts on members of the Crassulaceae. Only one other rust is known to parasitize Kalanchoe spp. A DNA sequence of A. kalanchoe suggests that the teleomorph is related to Puccinia.

  8. Identification of leaf rust resistant gene Lr10 in Pakistani wheat ...

    African Journals Online (AJOL)

    Leaf (brown) rust is the major disease of wheat in Pakistan and other countries. The disease is more effectively controlled when several rust resistance genes are pyramided into a single line. Molecular survey was conducted to screen 25 Pakistan wheat germplasm for the presence of leaf rust resistance gene Lr10 using ...

  9. Genetic characterization of stem rust resistance in a global spring wheat germplasm collection

    Science.gov (United States)

    Stem rust is considered one of the most damaging diseases of wheat. The recent emergence of the stem rust Ug99 race group poses a serious threat to world wheat production. Utilization of genetic resistance in cultivar development is the optimal way to control stem rust. Here we report association ma...

  10. Attempts to induce mutations for resistance of wheat to mildew, stem rust and leaf rust

    International Nuclear Information System (INIS)

    Kiraly, Z.; Barabas, Z.

    1983-01-01

    Research carried out between 1971 and 1981 is summarized. Attempts to find induced mutants with full resistance to pathotype mixtures of the three pathogens were not successful. Reasons are discussed. Studies on wheat lines tolerant to stem rust infection led to the conclusion that this disease reaction may be often accompanied by a reduced number of infection sites and a longer lag period resulting in reduced spore production. Various selection methods have been evaluated. Selecting for the multigenic 'non race specific' way is promising. (author)

  11. Roadway striping productivity data analysis for INDOT Greenfield and Crawfordsville districts.

    Science.gov (United States)

    2013-11-01

    The main objective of the SPR3650 project is to provide an accurate overview of striping operation so that INDOT finds a way to : effectively save significant investment for purchasing new striping trucks in near future without compromising roadwa...

  12. Twin InSb/GaAs quantum nano-stripes: Growth optimization and related properties

    Science.gov (United States)

    Narabadeesuphakorn, Phisut; Thainoi, Supachok; Tandaechanurat, Aniwat; Kiravittaya, Suwit; Nuntawong, Noppadon; Sopitopan, Suwat; Yordsri, Visittapong; Thanachayanont, Chanchana; Kanjanachuchai, Songphol; Ratanathammaphan, Somchai; Panyakeow, Somsak

    2018-04-01

    Growth of InSb/GaAs quantum nanostructures on GaAs substrate by using molecular beam epitaxy with low growth temperature and slow growth rate typically results in a mixture of isolated and paired nano-stripe structures, which are termed as single and twin nano-stripes, respectively. In this work, we investigate the growth conditions to maximize the number ratio between twin and single nano-stripes. The highest percentage of the twin nano-stripes of up to 59% was achieved by optimizing the substrate temperature and the nano-stripe growth rate. Transmission electron microscopy reveals the substantial size and height reduction of the buried nano-stripes. We also observed the Raman shift and photon emission from our twin nano-stripes. These twin nano-stripes are promising for spintronics and quantum computing devices.

  13. Identification of New Resistance Loci to African Stem Rust Race TTKSK in Tetraploid Wheats Based on Linkage and Genome-Wide Association Mapping.

    Science.gov (United States)

    Laidò, Giovanni; Panio, Giosuè; Marone, Daniela; Russo, Maria A; Ficco, Donatella B M; Giovanniello, Valentina; Cattivelli, Luigi; Steffenson, Brian; de Vita, Pasquale; Mastrangelo, Anna M

    2015-01-01

    Stem rust, caused by Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn. (Pgt), is one of the most destructive diseases of wheat. Races of the pathogen in the "Ug99 lineage" are of international concern due to their virulence for widely used stem rust resistance genes and their spread throughout Africa. Disease resistant cultivars provide one of the best means for controlling stem rust. To identify quantitative trait loci (QTL) conferring resistance to African stem rust race TTKSK at the seedling stage, we evaluated an association mapping (AM) panel consisting of 230 tetraploid wheat accessions under greenhouse conditions. A high level of phenotypic variation was observed in response to race TTKSK in the AM panel, allowing for genome-wide association mapping of resistance QTL in wild, landrace, and cultivated tetraploid wheats. Thirty-five resistance QTL were identified on all chromosomes, and seventeen are of particular interest as identified by multiple associations. Many of the identified resistance loci were coincident with previously identified rust resistance genes; however, nine on chromosomes 1AL, 2AL, 4AL, 5BL, and 7BS may be novel. To validate AM results, a biparental population of 146 recombinant inbred lines was also considered, which derived from a cross between the resistant cultivar "Cirillo" and susceptible "Neodur." The stem rust resistance of Cirillo was conferred by a single gene on the distal region of chromosome arm 6AL in an interval map coincident with the resistance gene Sr13, and confirmed one of the resistance loci identified by AM. A search for candidate resistance genes was carried out in the regions where QTL were identified, and many of them corresponded to NBS-LRR genes and protein kinases with LRR domains. The results obtained in the present study are of great interest as a high level of genetic variability for resistance to race TTKSK was described in a germplasm panel comprising most of the tetraploid wheat sub-species.

  14. 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.

  15. Visual acuity in the striped skunk (Mephitis mephitis).

    Science.gov (United States)

    Johnson-Ulrich, Zoe; Hoffmaster, Eric; Robeson, Audrey; Vonk, Jennifer

    2017-11-01

    The visual acuity of striped skunks (Mephitis mephitis) was tested using a 2 alternative forced-choice task with square wave gratings. Skunks were reinforced with food items for touching a ball in front of a striped stimulus when paired with a ball in front of a solid gray stimulus. Skunks demonstrated a maximum visual acuity of 0.42 cycles per degree when tested with bright outdoor illumination. This poor visual acuity may be due to their nocturnal lifestyle, lack of predation, and is consistent with their preferential use of smell and sound during foraging. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Characterization of Arsenic Contamination on Rust from Ton Containers

    Energy Technology Data Exchange (ETDEWEB)

    Gary S. Groenewold; Recep Avci; Robert V. Fox; Muhammedin Deliorman; Jayson Suo; Laura Kellerman

    2013-01-01

    The speciation and spatial distribution of arsenic on rusted steel surfaces affects both measurement and removal approaches. The chemistry of arsenic residing in the rust of ton containers that held the chemical warfare agents bis(2-chloroethyl)sulfide (sulfur mustard) and 2-chlorovinyldichloroarsine (Lewisite) is of particular interest, because while the agents have been decontaminated, residual arsenic could pose a health or environmental risk. The chemistry and distribution of arsenic in rust samples was probed using imaging secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy, and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX). Arsenic in the +3 and or +5 oxidation state is homogeneously distributed at the very top-most layer of the rust samples, and is intimately associated with iron. Sputter depth profiling followed by SIMS and XPS shows As at a depth of several nm, in some cases in a reduced form. The SEM/EDX experiments show that As is present at a depth of several microns, but is inhomogeneously distributed; most locations contained oxidized As at concentrations of a few percent, however several locations showed very high As in a metallic form. These results indicate that the rust material must be removed if the steel containers are to be cleared of arsenic.

  17. Painting rusted steel: The role of aluminum phosphosilicate

    International Nuclear Information System (INIS)

    Roselli, S.N.; Amo, B. del; Carbonari, R.O.; Di Sarli, A.R.; Romagnoli, R.

    2013-01-01

    Highlights: •Aluminum phosphosilicate is an acid pigment which could act as mild phosphating agent. •Aluminum phosphosilicate can phosphatize iron oxides on rusted surfaces. •Aluminum phosphosilicate is compatible with acid binders. •Aluminum phosphosilicate could replace chromate in complete painting schemes. •Aluminum phosphosilicate primers improve paints adhesion on rusted surfaces. -- Abstract: Surface preparation is a key factor for the adequate performance of a paint system. The aim of this investigation is to employ a wash-primer to accomplish the chemical conversion of rusted surface when current cleaning operations are difficult to carry out. The active component of the wash-primer was aluminum phosphosilicate whose electrochemical behavior and the composition of the generated protective layer, both, were studied by electrochemical techniques and scanning electron microscopy (SEM), respectively. Primed rusted steel panels were coated with an alkyd system to perform accelerated tests in the salt spray chamber and electrochemical impedance measurements (EIS). These tests were conducted in parallel with a chromate wash primer and the same alkyd system. Results showed that the wash-primer containing aluminum phosphosilicate could be used satisfactorily to paint rusted steel exhibiting a similar performance to the chromate primer

  18. Genome Sequence of Acidovorax avenae Strain T10_61 Associated with Sugarcane Red Stripe in Argentina

    Science.gov (United States)

    Fontana, Cecilia A.; Bassi, Daniela; Puglisi, Edoardo; Salazar, Sergio M.; Vignolo, Graciela M.; Coccocelli, Pier S.

    2016-01-01

    Red stripe of sugarcane in Argentina is a bacterial disease caused by Acidovorax avenae. The genome sequence from the first isolate of this bacterium in Argentina is presented here. The draft genome of the A. avenae T10_61 strain contains 5,646,552 bp and has a G+C content of 68.6 mol%. PMID:26847889

  19. The gene Sr33, an ortholog of barley Mla genes, encodes resistance to wheat stem rust race Ug99.

    Science.gov (United States)

    Periyannan, Sambasivam; Moore, John; Ayliffe, Michael; Bansal, Urmil; Wang, Xiaojing; Huang, Li; Deal, Karin; Luo, Mingcheng; Kong, Xiuying; Bariana, Harbans; Mago, Rohit; McIntosh, Robert; Dodds, Peter; Dvorak, Jan; Lagudah, Evans

    2013-08-16

    Wheat stem rust, caused by the fungus Puccinia graminis f. sp. tritici, afflicts bread wheat (Triticum aestivum). New virulent races collectively referred to as "Ug99" have emerged, which threaten global wheat production. The wheat gene Sr33, introgressed from the wild relative Aegilops tauschii into bread wheat, confers resistance to diverse stem rust races, including the Ug99 race group. We cloned Sr33, which encodes a coiled-coil, nucleotide-binding, leucine-rich repeat protein. Sr33 is orthologous to the barley (Hordeum vulgare) Mla mildew resistance genes that confer resistance to Blumeria graminis f. sp. hordei. The wheat Sr33 gene functions independently of RAR1, SGT1, and HSP90 chaperones. Haplotype analysis from diverse collections of Ae. tauschii placed the origin of Sr33 resistance near the southern coast of the Caspian Sea.

  20. 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 Management...

  1. Simultaneous Transfer of Leaf Rust and Powdery Mildew Resistance Genes from Hexaploid Triticale Cultivar Sorento into Bread Wheat

    Directory of Open Access Journals (Sweden)

    Feng Li

    2018-02-01

    Full Text Available Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, and wheat leaf rust, caused by Puccinia triticina Eriks, are two important diseases that severely threaten wheat production. Sorento, a hexaploid triticale cultivar from Poland, shows high resistance to the wheat powdery mildew isolate E09 and the leaf rust isolate PHT in Beijing, China. To introduce resistance genes into common wheat, Sorento was crossed with wheat line Xuezao, which is susceptible to both diseases, and the F1 hybrids were then backcrossed with Xuezao as the recurrent male parent. By marker analysis, we demonstrate that the long arm of the 2R (2RL chromosome confers resistance to both the leaf rust and powdery mildew isolates at adult-plant and seedling stages, while the long arm of 4R (4RL confers resistance only to powdery mildew at both stages. The chromosomal composition of BC2F3 plants containing 2R or 2RL and 4R or 4RL in the form of substitution and translocation were confirmed by GISH (genomic in situ hybridization and FISH (fluorescence in situ hybridization. Monosomic and disomic substitutions of a wheat chromosome with chromosome 2R or 4R, as well as one 4RS-4DL/4DS-4RL reciprocal translocation homozigote and one 2RL-1DL translocation hemizigote, were recovered. Such germplasms are of great value in wheat improvement.

  2. Effects of sowing time on pink snow mould, leaf rust and winter damage in winter rye varieties in Finland

    Directory of Open Access Journals (Sweden)

    M. SERENIUS

    2008-12-01

    Full Text Available Disease infection in relation to sowing time of winter rye (Secale cereale was studied in southern Finland in order to compare overwintering capacity of modern rye varieties and to give recommendations for rye cultivation. This was done by using three sowing times and four rye varieties in field trials conducted at three locations in 1999–2001. The early sown rye (beginning of August was severely affected by diseases caused by Puccinia recondita and Microdochium nivale, whereas postponing sowing for two weeks after the recommended sowing time resulted in considerably less infection. The infection levels of diseases differed among rye varieties. Finnish rye varieties Anna and Bor 7068 were more resistant to snow mould and more winter hardy than the Polish variety Amilo, or the German hybrid varieties Picasso and Esprit. However, Amilo was the most resistant to leaf rust. In the first year snow mould appeared to be the primary cause of winter damage, but in the second year the winter damage was positively correlated with leaf rust. No significant correlation between frit fly infestation and winter damage or disease incidence of snow mould or leaf rust was established. The late sowing of rye (in the beginning of September is recommended in Finland, particularly with hybrid varieties, to minimize the need for chemical plant protection in autumn.;

  3. Efeito de herbicidas e fungicidas nas curvas de progresso e quantificação de danos causados pela ferrugem asiática da soja Effect of herbicides and fungicides on progress curves and damage quantification caused by soybean rust

    Directory of Open Access Journals (Sweden)

    Guy Mitsuyuki Tsumanuma

    2010-07-01

    regions around the world, where great losses were observed. Many variables are studied in the quantification of damage such as area under the disease progress curve (AUDPC, healthy leaf area absorption (HAA, healthy leaf area duration (HAD, in addition to disease progress curves. The present research aimed to evaluate the effect of several herbicides and fungicides on the progress of the disease and its implications for variables related to healthy leaf area and yield. The treatments were evaluated in two cultivars (MG/BR-46 Conquista e BRS Valiosa RR: 1. Control; 2. Control with herbicides; 3. Herbicides and pyraclostrobin (V4 + pyraclostrobin+ epoxiconazole (R2 and R5.1, 4. Herbicides and pyraclostrobin (V4 + epoxiconazole (R2 and R5.1. 5. Herbicides (V4 + pyraclostrobin + epoxiconazole (R2 and R5.1. The herbicides used in MG/BR-46 Conquista were sethoxydim, bentazon and chlorimuron-ethyl; in BRS Valiosa RR, glyphosate was used. The logistic was the model that best adapted to the mean severity ratings and the disease progress curve. At the bottom of canopy, position more favorable to this disease, the logistic model with variable rate was the model that better explain the data. The spraying of strobilurin's group associated with triazole (pyraclostrobin + epoxiconazole reduced the rate of asian rust development, in relation to the group of ergosterol biosynthesis inhibitors fungicide (epoxiconazole. The pyraclostrobin + epoxiconazole influenced the variables AUDPC, HAA and HAD, and these can be considered suitable to quantify damage caused by this disease. In MG/BR-46 Conquista, the herbicides action affects temporarily the leaf area, affecting indirectly the HAA and HAD variables.

  4. Genetics and mapping of seedling resistance to Ug99 stem rust in Canadian wheat cultivars 'Peace' and 'AC Cadillac'.

    Science.gov (United States)

    Hiebert, Colin W; Fetch, Tom G; Zegeye, Taye; Thomas, Julian B; Somers, Daryl J; Humphreys, D Gavin; McCallum, Brent D; Cloutier, Sylvie; Singh, Davinder; Knott, Doug R

    2011-01-01

    Stem rust (caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn.) has re-emerged as a threat to wheat production with the evolution of new pathogen races, namely TTKSK (Ug99) and its variants, in Africa. Deployment of resistant wheat cultivars has provided long-term control of stem rust. Identification of new resistance genes will contribute to future cultivars with broad resistance to stem rust. The related Canadian cultivars Peace and AC Cadillac show resistance to Ug99 at the seedling stage and in the field. The purpose of this study was to elucidate the inheritance and genetically map resistance to Ug99 in these two cultivars. Two populations were produced, an F(2:3) population from LMPG/AC Cadillac and a doubled haploid (DH) population from RL6071/Peace. Both populations showed segregation at the seedling stage for a single stem rust resistance (Sr) gene, temporarily named SrCad. SrCad was mapped to chromosome 6DS in both populations with microsatellite markers and a marker (FSD_RSA) that is tightly linked to the common bunt resistance gene Bt10. FSD_RSA was the closest marker to SrCad (≈ 1.6 cM). Evaluation of the RL6071/Peace DH population and a second DH population, AC Karma/87E03-S2B1, in Kenya showed that the combination of SrCad and leaf rust resistance gene Lr34 provided a high level of resistance to Ug99-type races in the field, whereas in the absence of Lr34 SrCad conferred moderate resistance. A survey confirmed that SrCad is the basis for all of the seedling resistance to Ug99 in Canadian wheat cultivars. While further study is needed to determine the relationship between SrCad and other Sr genes on chromosome 6DS, SrCad represents a valuable genetic resource for producing stem rust resistant wheat cultivars.

  5. Studies on stem and leaf rust resistance in wheat

    International Nuclear Information System (INIS)

    Knott, D.R.

    1983-01-01

    Stem and leaf rust resistance was successfully transferred from Agropyron to wheat by radiation-induced translocations. Mutation induction subsequently proved to be useful in separating an undesired gene for yellow pigment from the resistance. The homoeologous pairing mutant obtained by Sears was also used successfully in obtaining transfers through crossing-over between wheat and Agropyron chromosomes. Another experimental series succeeded in accumulating minor genes for rust resistance, after eliminating major genes for specific resistance. The resistance is polygenic and widely effective although not general. It is recessively inherited, and hoped to be more durable than major gene resistance used so far in the Canadian prairies. An attempt to induce mutations for leaf rust resistance in a small-scale experiment with leading Canadian wheat varieties Manitou and Neepawa using gamma rays and EMS has not been successful. (author)

  6. Induced mutations for resistance to leaf rust in wheat

    International Nuclear Information System (INIS)

    Borojevic, K.

    1983-01-01

    Problems related to the induction of mutations for disease resistance were investigated under several aspects, using the wheat/leaf rust system. Previously selected mutant lines, tested in M 11 and M 13 , were found to differ with regard to infection type and disease severity from the original varieties. To verify the induced-mutation origin, these mutants were examined further using test crosses with carriers of known genes for leaf rust resistance and electrophoresis. A separate experiment to induce mutations for leaf rust resistance in the wheat varieties Sava, Aurora and Siete Cerros, using gamma rays, fast neutrons and EMS, yielded mutants with different disease reaction in the varieties Sava and Aurora at a frequency of about 1x10 - 3 per M 1 plant progenies. (author)

  7. Identification of a soybean rust resistance gene in PI 567104B.

    Science.gov (United States)

    Liu, Min; Li, Shuxian; Swaminathan, Sivakumar; Sahu, Binod B; Leandro, Leonor F; Cardinal, Andrea J; Bhattacharyya, Madan K; Song, Qijian; Walker, David R; Cianzio, Silvia R

    2016-05-01

    Using a combination of phenotypic screening and molecular, statistical, and linkage analyses, we have mapped a dominant soybean rust resistance gene in soybean PI 567104B. Asian soybean rust (SBR), caused by the fungus Phakopsora pachyrhizi Syd. and P. Syd., is one of the most economically important diseases that affect soybean production worldwide. A long-term strategy for minimizing the effects of SBR is the development of genetically resistant cultivars. The objectives of the study were to identify the location of a rust-resistance (Rpp) gene(s) in plant introduction (PI) 567104B, and to determine if the gene(s) in PI 567104B was different from previously mapped Rpp loci. The progeny of the cross of 'IAR 2001 BSR' × PI 567104B was phenotyped from field assays of the F 2:3 and F 4:5 generations and from a growth chamber assay of 253 F 5:6 recombinant inbred lines (RILs). For the growth chamber, the phenotyping was conducted by inoculation with a purified 2006 fungal isolate from Mississippi. A resistance gene locus on PI 567104B was mapped to a region containing the Rpp6 locus on chromosome 18. The high level of resistance of F 1 plants from two other crosses with PI 567104B as one of the parents indicated that the gene from PI 567104B was dominant. The interval containing the gene is flanked by the simple sequence repeat (SSR) markers Satt131 and Satt394, and includes the SSR markers BARCSOYSSR_18_0331 and BARCSOYSSR_18_0380. The results also indicated that the resistance gene from PI 567104B is different from the Rpp1 to the Rpp4 genes previously identified. To determine if the gene from PI 567104B is different from the Rpp6 gene from PI 567102B, additional research will be required.

  8. SH1 leaf rust and bacterial halo blight coffee resistances are genetically independent

    Directory of Open Access Journals (Sweden)

    Lucas Mateus Rivero Rodrigues

    Full Text Available ABSTRACT Coffee resistance to Pseudomonas syringae pv. garcae has been associated to pleiotropic effect of SH1 allele, present in coffee plants resistant to certain races of Hemileia vastatrix, the causal agent of leaf rust, or genetic linkage between resistance alleles to both pathogens. To validate this hypothesis, 63 coffee plants in F2 generation were evaluated for resistance to 2 isolates of H. vastatrix carriers of alleles, respectively, v2, v5 (isolate I/2015 and v1; v2; v5 (isolate II/2015 with the objective to confirm presence of SH1 allele in resistant plants to isolate I/2015. The same coffee plants were evaluated for resistance to a mixture of P. syringae pv. garcae strains highly pathogenic to coffee. Results showed that, among F2 coffee allele SH1 carriers, resistant to isolate I/2015, resistant and susceptible plants to bacterial halo blight were found; the same segregation occurs between F2 homozygous for SH1 allele, susceptible to the same isolate (I/2015 of H. vastatrix. Results also indicate that there is no pleiotropic effect of gene or allele SH1 connection between genes conferring resistance to leaf rust caused by H. vastatrix and bacterial halo blight caused by P. syringae pv. garcae.

  9. 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.

  10. Anatomical studies of the gastrointestinal tract of the striped sand ...

    African Journals Online (AJOL)

    A study was carried out on the gross anatomical, morphometric features and histology of the gastrointestinal tract of the Striped Sand Snake (Psammophis sibilans). Ten snakes (five males and five females) were euthanized and dissected for the study. The gastrointestinal tract appeared as a straight tubular organ from oral ...

  11. Stripe domains and magnetoresistance in thermally deposited nickel films

    International Nuclear Information System (INIS)

    Sparks, P.D.; Stern, N.P.; Snowden, D.S.; Kappus, B.A.; Checkelsky, J.G.; Harberger, S.S.; Fusello, A.M.; Eckert, J.C.

    2004-01-01

    We report a study of the domain structure and magnetoresistance of thermally deposited nickel films. For films thicker than 17 nm, we observe striped domains with period varying with film thickness as a power law with exponent 0.21±0.02 up to 120 nm thickness. There is a negative magnetoresistance for fields out of the plane

  12. Distribution patterns of striped mullet Mugil cephalus in mangrove ...

    African Journals Online (AJOL)

    Spatial and seasonal variations in density of striped mullet Mugil cephalus were investigated in four mangrove creeks in Zanzibar, Tanzania, during a one-year cycle. Fish were collected monthly in the lower, intermediate and upper reaches of each creek using a beach-seine net. All fish collected were juveniles between 2 ...

  13. Intervertebral Disk Disease in 3 Striped Skunks (Mephitis mephitis)

    NARCIS (Netherlands)

    Krauss, M.W.; Benato, L.; McDonnell, J.; Schoemaker, N.J.; Westerhof, I.; Bronson, E.; Gielen, I.; van Caelenberg, A.; Hellebuyck, T.; Meij, B.P.; de Decker, S.

    Objective To describe diagnostic findings, surgical technique, and outcome in 3 striped skunks (Mephitis mephitis) with a history of paraparesis. Study Design Case series. Animals Skunks (n = 3) with paraparesis. Methods Neurologic examination revealed upper motor neuron disease (T2–L2) in 2 skunks

  14. Modulation of the innate immune responses in the striped ...

    African Journals Online (AJOL)

    Thus, most of the innate non-specific immune responses are inducible though they are constitutive of fish immune system exhibiting a basal level of activity even in the absence of pathogen challenge. Keywords: Aeromonas hydrophila, Experimental challenge, Innate immune response, Striped snakehead murrel ...

  15. 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

  16. 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

    2016-07-27

    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.

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

    Directory of Open Access Journals (Sweden)

    Qiaolin Dong

    2016-07-01

    Full Text Available 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.

  18. Genetic Resistance to Rust of Eucalyptus urophylla Progenies

    Directory of Open Access Journals (Sweden)

    André Carignato

    2018-02-01

    Full Text Available ABSTRACT This study assessed the genetic variability in open-pollinated progenies of Eucalyptus urophylla for resistance to rust (Puccinia psidii. The progeny trial was conducted on a statistical randomized block design with 20 progenies, five plants per plot, and nine replications. Analysis of variance showed high genetic variability for the studied trait, with potential for selection gains. The genetic variability of this population provides support to conduct a breeding program with superior individuals for rust resistance, allowing low costs and minimizing the yield losses on eucalyptus plantations.

  19. Use of gamma radiation for inducing rust resistance in soybean

    International Nuclear Information System (INIS)

    Smutkupt, Sumit; Wongpiyasatid, Arunee; Lamseejan, Siranut; Naritoom, Kruik

    1982-01-01

    Experiments on induced mutations for rust resistance in 11 soybean cultivars were started in the rainy season of 1979. M 1 seeds were grown at Farm Suwan, Pak Chong, Nakorn Rajchasima Province. Six plods from each of 4,438 control and 43,907 M 1 plants were randomly harvested. M 2 seeds of each cultivar of different doses were bulked. In addition, 270 good M 1 plants were selected and threshed singly. M 2 -bulk and M 2 -single seeds were advanced to M 3 . Both of M 3 -bulk and M 3 -single plants together with M 2 -bulk plants derived from remnant M 2 seeds were screened for rust resistance in the rainy season of 1980. The IWGSR rust rating system was used. Based on the slow growth of rust reaction on the plant (323,333) compared with the average IWGSR rust rating notation of the rates (343) in the same row, 121 plants were selected. Among them, six were selected from a total of 2802 control plants, and 115 from a total of 28,834 M 2 and M 3 plants. Seeds of each selection harvested. Only 88 lines of M 4 and M 5 were available for further rust evaluation in the rainy season of 1981. The results were as follows: At 77 days after planting, 82 selected lines were rated 333, 323 in comparison with 87 out of 137 rows of control S.J.1, S.J.2, S.J.4 and T.K.5 were rated 343. At 86 days after planting, most of the selections reached the diseased level 343. However, six lines which were derived from G8586 were still rated 333. In addition, a plant with slow growth of rust (323) from Taichung N No. 81-1-032 was selected. The six selected lines having characteristics of slow growth of rust reaction on the plants will be further tested. The high yielding selections among 82 selected lines having low percentage of shrivelled seeds will be used for further yield evaluation in the rainy season of 1982

  20. Crosstalk reduction in large-scale autostereoscopic 3D-LED display based on black-stripe occupation ratio

    Science.gov (United States)

    Zeng, Xiang-Yao; Zhou, Xiong-Tu; Guo, Tai-Liang; Yang, Lan; Chen, En-Guo; Zhang, Yong-Ai

    2017-04-01

    Autostereoscopic 3D-LED displays using parallax barriers have several advantages. However, conventional designs do not consider the black stripes of regular LED panels. These cause immeasurable crosstalk owing to excess light from adjacent sub-pixels separated by the panels. To reduce the crosstalk in large-scale displays, we design a barrier in which the black-stripe occupation ratio is defined to quantify the crosstalk level in the LED system. A prototype is assembled and analyzed based on a three-in-one pixel LED-chip panel for a dual-viewpoint display. The improved parallax barrier meets the design requirements and achieves a low crosstalk level. Simulation and experiment results verify the effectiveness of the crosstalk-reduced design.

  1. Distinct Nature of Static and Dynamic Magnetic Stripes in Cuprate Superconductors

    Science.gov (United States)

    Jacobsen, H.; Holm, S. L.; Lǎcǎtuşu, M.-E.; Rømer, A. T.; Bertelsen, M.; Boehm, M.; Toft-Petersen, R.; Grivel, J.-C.; Emery, S. B.; Udby, L.; Wells, B. O.; Lefmann, K.

    2018-01-01

    We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-temperature superconductor, La2 CuO4 +y . We observe that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. Therefore, the dynamic stripes observed in neutron scattering experiments are not the Goldstone modes associated with the broken symmetry of the simultaneously observed static stripes, and the signals originate from different domains in the sample. These observations support real-space electronic phase separation in the crystal, where the static stripes in one phase are pinned versions of the dynamic stripes in the other, having slightly different periods. Our results explain earlier observations of unusual dispersions in underdoped La2 -xSrx CuO4 (x =0.07 ) and La2 -xBax CuO4 (x =0.095 ).

  2. Distinct Nature of Static and Dynamic Magnetic Stripes in Cuprate Superconductors

    DEFF Research Database (Denmark)

    Jacobsen, H.; Holm, S. L.; Lăcătuşu, M. E.

    2018-01-01

    We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-Temperature superconductor, La2CuO4+y. We observe that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. Therefore, the dynamic stripes...... observed in neutron scattering experiments are not the Goldstone modes associated with the broken symmetry of the simultaneously observed static stripes, and the signals originate from different domains in the sample. These observations support real-space electronic phase separation in the crystal, where...... the static stripes in one phase are pinned versions of the dynamic stripes in the other, having slightly different periods. Our results explain earlier observations of unusual dispersions in underdoped La2-xSrxCuO4 (x=0.07) and La2-xBaxCuO4 (x=0.095)....

  3. MicroRNAs in loblolly pine (Pinus taeda L.) and their association with fusiform rust gall development.

    Science.gov (United States)

    Lu, Shanfa; Sun, Ying-Hsuan; Amerson, Henry; Chiang, Vincent L

    2007-09-01

    MicroRNAs (miRNAs) are endogenous small RNAs that can have large-scale regulatory effects on development and on stress responses in plants. The endemic rust fungus Cronartium quercuum f. sp. fusiforme causes fusiform rust disease in pines, resulting in the development of spindle-shaped galls (cankers) on branches or stems. This disease is the most destructive disease of pines in the southern USA. To test whether miRNAs play roles in fusiform rust gall development, we cloned and identified 26 miRNAs from stem xylem of loblolly pine (Pinus taeda), which belong to four conserved and seven loblolly pine-specific miRNA families. Forty-three targets for nine of these 11 families were experimentally validated in vivo. Sequence analysis suggested that the target cleavage site may be determined not only by the miRNA sequence but also by the target sequence. Members of three loblolly pine-specific miRNA families target a large number of non-protein coding transcripts, and one of these families could also initiate secondary phased production from its target of a putative trans-acting short interfering RNA (ta-siRNA). Expression of 10 of these 11 miRNA families was significantly repressed in the galled stem. PCR-based transcript quantification showed complex expression patterns of these miRNAs and their targets in the galled tissues and in tissues surrounding the gall. We further predict 82 plant disease-related transcripts that may also response to miRNA regulation in pine. These results reveal a new genetic basis for host-pathogen interactions in the development of fusiform rust gall.

  4. Inheritance of resistance to Ug99 stem rust in wheat cultivar Norin 40 and genetic mapping of Sr42.

    Science.gov (United States)

    Ghazvini, Habibollah; Hiebert, Colin W; Zegeye, Taye; Liu, Sixin; Dilawari, Mridull; Tsilo, Toi; Anderson, James A; Rouse, Matthew N; Jin, Yue; Fetch, Tom

    2012-08-01

    Stem rust, caused by Puccinia graminis f. sp. tritici, is a devastating disease of wheat. The emergence of race TTKSK (Ug99) and new variants in Africa threatens wheat production worldwide. The best method of controlling stem rust is to deploy effective resistance genes in wheat cultivars. Few stem rust resistance (Sr) genes derived from the primary gene pool of wheat confer resistance to TTKSK. Norin 40, which carries Sr42, is resistant to TTKSK and variants TTKST and TTTSK. The goal of this study was to elucidate the inheritance of resistance to Ug99 in Norin 40 and map the Sr gene(s). A doubled haploid (DH) population of LMPG-6/Norin 40 was evaluated for resistance to the race TTKST. Segregation of 248 DH lines fitted a 1:1 ratio (χ (2) 1:1= 0.58, p = 0.45), indicating a single gene in Norin 40 conditioned resistance to Ug99. This was confirmed by an independent F(2:3) population also derived from the cross LMPG-6/Norin 40 where a 1:2:1 ratio (χ (2)1:2:1 = 0.69, p = 0.71) was observed following the inoculation with race TTKSK. Mapping with DNA markers located this gene to chromosome 6DS, the known location of Sr42. PCR marker FSD_RSA co-segregated with Sr42, and simple sequence repeat (SSR) marker BARC183 was closely linked (0.5 cM) to Sr42. A previous study found close linkage between FSD_RSA and SrCad, a temporarily designated gene that also confers resistance to Ug99, thus Sr42 may be the same gene or allelic. Marker FSD_RSA is suitable for marker-assisted selection (MAS) in wheat breeding programs to improve stem rust resistance, including Ug99.

  5. Tidal-Induced Internal Ocean Waves as an Explanation for Enceladus' Tiger Stripe Pattern and Hotspot Activity

    Science.gov (United States)

    Vermeersen, B. L. A.; Maas, L. R.; van Oers, S.; Rabitti, A.; Jara-Orue, H.

    2014-12-01

    One of the most peculiar features on Saturn moon Enceladus is its so-called tiger stripe pattern at the geologically active South Polar Terrain (SPT), as first observed in detail by the Cassini spacecraft early 2005. It is generally assumed that the four almost parallel surface lines that constitute this pattern are faults in the icy surface overlying a confined salty water reservoir. Indeed, later Cassini observations have shown that salty water jets originate from the tiger stripes [e.g., Hansen et al., Science, 311, 1422-1425, 2006; Postberg et al., Nature, 474, 620-622, 2011]. More recently, Porco et al. [Astron. J., 148:45, Sep. 2014] and Nimmo et al. [Astron. J., 148:46, Sep. 2014] have reported strong evidence that the geysers are not caused by frictional heating at the surface, but that geysers must originate deeper in Enceladus' interior. Tidal flexing models, like those of Hurford et al., Nature, 447, 292-294, 2007, give a good match for the brightness variations Cassini observes, but they seem to fail to reproduce the exact timing of plume brightening. Although jet activity is thus strongly connected to tidal forcing, another mechanism must be involved as well. Last year, we formulated the original idea [Vermeersen et al., AGU Fall Meeting 2013, abstract #P53B-1848] that the tiger stripe pattern is formed and maintained by induced, tidally and rotationally driven, wave-attractor motions in the ocean underneath the icy surface of the tiger-stripe region. Such wave-attractor motions are observed in water tank experiments in laboratories on Earth and in numerical experiments [Maas et al., Nature, 338, 557-561, 1997; Drijfhout and Maas, J. Phys. Oceanogr., 37, 2740-2763, 2007; Hazewinkel et al., Phys. Fluids, 22, 107102, 2010]. The latest observations by Porco et al. and Nimmo et al. seem to be in agreement with this tidal-induced wave attractor phenomenon, both with respect to tiger stripe pattern and with respect to timing of hotspot activity. However, in

  6. Expansion of the South China Sea basin: Constraints from magnetic anomaly stripes, sea floor topography, satellite gravity and submarine geothermics

    Directory of Open Access Journals (Sweden)

    Xuezhong Yu

    2017-01-01

    Full Text Available The widely distributed E–W-trending magnetic anomaly stripes in the central basin and the N–E-trending magnetic anomaly stripes in the southwest sub-basin provide the most important evidence for Neogene expansion of the South China Sea. The expansion mechanism remains, however, controversial because of the lack of direct drilling data, non-systematic marine magnetic survey data, and irregular magnetic anomaly stripes with two obvious directions. For example, researchers have inferred different ages and episodes of expansion for the central basin and southwest sub-basin. Major controversy centers on the order of basinal expansion and the mechanism of expansion for the entire South China Sea basin. This study attempts to constrain these problems from a comprehensive analysis of the seafloor topography, magnetic anomaly stripes, regional aeromagnetic data, satellite gravity, and submarine geothermics. The mapped seafloor terrain shows that the central basin is a north-south rectangle that is relatively shallow with many seamounts, whereas the southwest sub-basin is wide in northeast, gradually narrows to the southwest, and is relatively deeper with fewer seamounts. Many magnetic anomaly stripes are present in the central basin with variable dimensions and directions that are dominantly EW-trending, followed by the NE-, NW- and NS-trending. Conversely such stripes are few in the southwest sub-basin and mainly NE-trending. Regional magnetic data suggest that the NW-trending Ailaoshan-Red River fault extends into the South China Sea, links with the central fault zone in the South China Sea, which extends further southward to Reed Tablemount. Satellite gravity data show that both the central basin and southwest sub-basin are composed of oceanic crust. The Changlong seamount is particularly visible in the southwest sub-basin and extends eastward to the Zhenbei seamount. Also a low gravity anomaly zone coincides with the central fault zone in the sub

  7. Characterization and selection of location for resistance to sugarcane brown rust disease under cuban conditions

    Directory of Open Access Journals (Sweden)

    Joaquín Montalván Delgado

    2016-01-01

    Full Text Available The sugarcane brown rust disease is caused by fungus Puccinia melanocephala Sydow & P. Sydow and it is one of the more importance diseases. The environment where the sugarcane is cultivated is constituted by numerous factors and its combination contributes to the formation of different development and production conditions, what influences in the varietal disease resistance. With the objective of to characterize and to define the resistance tests location to the brown rust disease were carried out experiments in 6 location of the country. Eleven varieties and six patterns were studied. The climatic variables were analyzed during the period in each location and they were carried out evaluations in different ages of the plant and number of the leaves. The quantity of pustules, long of the most frequent pustules, size of the biggest pustules and area per - centage occupied by pustules were evaluated. The data were analyzed statistically. Differential behavior of the locations and the importance of the relative humidity and the temperatures in the manifestation of the disease symptoms were proven. All the locations were important although similarity exists between Matanzas and Villa Clara and between Camagüey and Holguín. Mayabeque and Santiago de Cuba didn’t present similarity with any other one. These 6 locations can be used for the resistance tests and to define the progenitors’ Santiago de Cuba, Holguín, Villa Clara and Mayabeque

  8. Control of Bean Rust using Antibiotics Produced by Bacillus and ...

    African Journals Online (AJOL)

    Antibiotic culture filtrates produced by Bacillus (CA5) and Streptomyces spp. were tested for translocation and persistence when applied on snap beans inoculated with rust (Uromyces appendiculatus) in greenhouse pot experiments. The antibiotics were applied on the first trifoliate leaves and translocation was assessed as ...

  9. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Journal of Genetics; Volume 96; Issue 6. Marker-assisted pyramiding of Thinopyrum-derived leaf rust resistance genes Lr19 and Lr24 in bread wheat variety ...

  10. Induced resistance and gene expression in wheat against leaf rust ...

    African Journals Online (AJOL)

    uvp

    2013-05-15

    May 15, 2013 ... pathogenesis related (PR) proteins (β-1,3-glucanase, chitinase and peroxidase). This was the case in both susceptible and resistant wheat lines whether the plants were uninfected or infected with leaf rust. (Puccinia triticina). The aim of this study was to determine the influence of the A. africanus extract on.

  11. Pathological and molecular characterizations of slow leaf rusting in ...

    African Journals Online (AJOL)

    Fifteen (15) wheat genotypes which also included multiple crosses with the aim to characterize pyramid resistance genes, including slow rusting genes like Lr46 and Lr50 were evaluated for disease severity percent, latent period and incubation period under field conditions. Detached leaf assay was also performed with ...

  12. Mössbauer study of some rust converters

    Science.gov (United States)

    Gancedo, J. R.; Gracia, M.; Francisco, W.; Morcillo, M.; Feliu, S.

    1989-03-01

    The ability “to transform rust” of nine commercial converters has been studied by Mossbauer spectroscopy. This technique fails to prove that all nine but one change the chemical nature of the rust previously formed on mild steel plates. Accelerated salt spray tests demonstrated a significant different performance for the studied products, whose effects range from deleterious to beneficial.

  13. 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,

  14. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    ... 97.27 and 98.94%, respectively, of genomic similarity with the parent cultivar, after two backcrossing and one generation of selfing.NILs were intercrossed to combine the genes Lr19 and Lr24. The combination of these two genes in the cultivarHD2733 is expected to provide durable leaf rust resistance in farmers' fields.

  15. Amino acid assisted dehalogenation of carbon tetrachloride by green rust

    DEFF Research Database (Denmark)

    Yin, Weizhao; Strobel, Bjarne W.; Hansen, Hans Chr. Bruun

    2017-01-01

    Layered FeII-FeIII hydroxides (green rusts, GR) are promising reactants for reductive dechlorination of chlorinated solvents due to high reaction rates and the opportunity to inject reactive slurries of the compounds into contaminant plumes. However, it is necessary to develop strategies...

  16. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    Mona Singh

    2017-12-08

    Dec 8, 2017 ... 2001, HD2733 was released for irrigated timely sown conditions of the north eastern plains zone (NEPZ) of India became susceptible to leaf rust, a major disease of the region. Background .... Lambda uncut DNA. Working DNA stocks were prepared by diluting in TE buffer to achieve final concentration of.

  17. Control of Bean Rust using Antibiotics Produced by Bacillus and ...

    African Journals Online (AJOL)

    MICHAEL

    ABSTRACT: Antibiotic culture filtrates produced by Bacillus (CA5) and Streptomyces spp. were tested for translocation and persistence when applied on snap beans inoculated with rust (Uromyces appendiculatus) in greenhouse pot experiments. The antibiotics were applied on the first trifoliate leaves and translocation was ...

  18. Taxonomy, phylogeny, and coevolution of pines and their stem rusts

    Science.gov (United States)

    C. I. Millar; B. B. Kinloch

    1991-01-01

    We review and reinterpret major events in the evolution of pines and their stem rusts using information from their taxonomy, genetics, biogeography, and fossil history. Understanding of pine evolution has been significantly revised in the last 20 years. Pines appear to have evolved early in the Mesozoic and to have diversified and migrated throughout middle latitudes...

  19. Genetic studies in wheat for leaf rust resistance (Puccinia recondita)

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... Additive and dominance, as well as epistatic genetic effects, are involved in the inheritance of leaf rust resistance. However, the narrow sense heritability estimates were low, which also exhibited the presence of epistatic genetic effects. Thus, selection of resistant adult plant in later segregating generations ...

  20. White pines, Ribes, and blister rust: integration and action

    Science.gov (United States)

    R. S. Hunt; B. W. Geils; K. E. Hummer

    2010-01-01

    The preceding articles in this series review the history, biology and management of white pine blister rust in North America, Europe and eastern Asia. In this integration, we connect and discuss seven recurring themes important for understanding and managing epidemics of Cronartium ribicola in the white pines (five-needle pines in subgenus Strobus). Information and...