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

Science.gov (United States)

2011-01-01

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. tritici (Pst), and poplar

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

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.

Chemical reduction of rust on 2 1/4 Cr-1 Mo steel surface in sodium

International Nuclear Information System (INIS)

Yokota, N.; Shimoyashiki, S.

1986-01-01

Low-alloy Fe-2 1/4 Cr-1 Mo ferritic steel has been favored for the tube material of steam generators in fast breeder reactors (FBRs). However, this material rusts easily due to moisture condensation on its surface when left in air. Therefore, measures to prevent tube materials from rusting have been taken during manufacturing of the steam generators. When rust is present on tube surfaces, its oxygen and iron dissolve into liquid sodium. When the concentration of these impurities in the sodium increases rapidly, the cold traps can become choked locally and lose their removal ability. This work has been done, therefore, to clarify reduction processes of rust in sodium and to select optimum operating temperatures of steam generators in the initial operation

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...

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

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).

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

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.

The use of Co2+ for crystallization and structure determination, using a conventional monochromatic X-ray source, of flax rust avirulence protein

International Nuclear Information System (INIS)

Gunčar, Gregor; Wang, Ching-I A.; Forwood, Jade K.; Teh, Trazel; Catanzariti, Ann-Maree; Ellis, Jeffrey G.; Dodds, Peter N.; Kobe, Boštjan

2007-01-01

It is demonstrated that anomalous diffraction based on the signal from a cobalt ion measured on a conventional monochromatic X-ray source can be used to determine the structure of a protein with a novel fold (M. lini avirulence protein AvrL567-A). The approach could be applicable to many metal-binding proteins, particularly when synchrotron radiation is not readily available. Metal-binding sites are ubiquitous in proteins and can be readily utilized for phasing. It is shown that a protein crystal structure can be solved using single-wavelength anomalous diffraction based on the anomalous signal of a cobalt ion measured on a conventional monochromatic X-ray source. The unique absorption edge of cobalt (1.61 Å) is compatible with the Cu Kα wavelength (1.54 Å) commonly available in macromolecular crystallography laboratories. This approach was applied to the determination of the structure of Melampsora lini avirulence protein AvrL567-A, a protein with a novel fold from the fungal pathogen flax rust that induces plant disease resistance in flax plants. This approach using cobalt ions may be applicable to all cobalt-binding proteins and may be advantageous when synchrotron radiation is not readily available

75 FR 53861 - Airworthiness Directives; Robert E. Rust, Jr. Model DeHavilland DH.C1 Chipmunk 21, DH.C1 Chipmunk...

Science.gov (United States)

2010-09-02

... Airworthiness Directives; Robert E. Rust, Jr. Model DeHavilland DH.C1 Chipmunk 21, DH.C1 Chipmunk 22, and DH.C1...). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Robert E. Rust... CFR part 39) to include an AD that would apply to all Robert E. Rust, Jr. Models DeHavilland DH.C1...

Wheat Rust Toolbox Related to New Initiatives on Yellow Rust

DEFF Research Database (Denmark)

Hansen, Jens Grønbech; Lassen, Poul

://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...... – 2009), and as soon as possible this will be expanded to cover all global yellow rust data available via the GRRC. The presentation will focus on experiences from the previous work on global databases and web based information systems, as well as propose ideas how the toolbox can be helpful regarding...

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

Synthesis and New Observations on Needle Pathogens of Larch in Northern Finland

Directory of Open Access Journals (Sweden)

Risto Jalkanen

2016-01-01

Full Text Available Needle pathogens of larch (Larix spp. in the Nordic countries are under-studied. Their incidence in Finland tends to be low and local, and this may be a function of enemy release, since species of larch were introduced to the region. Here, the ecology and incidence of larch needle pathogens and the abiotic factors that also affect larch in northern Finland are reviewed. Field observations and related laboratory analyses during the past 35 years have mainly been obtained near the Kivalo Research Area within the Arctic Circle, Finnish Lapland. The relatively recent introduction of Hypodermella laricis is a primary focus. This pathogen is not only new to Nordic countries, but can cause severe outbreaks, defoliation and crown-thinning in the canopies of all ages of most planted larch species worldwide. Symptoms of H. laricis clearly differ from those of Mycosphaerella laricina; the latter has affected Larix sibirica at high latitudes for decades. The effects of Meria laricis, Lophodermium laricinum, various rust fungi, and wind and frost are also discussed.

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)

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)

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)

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.

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

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

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...

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)

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...

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.

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

Haplotype structure around Bru1 reveals a narrow genetic basis for brown rust resistance in modern sugarcane cultivars.

Science.gov (United States)

Costet, L; Le Cunff, L; Royaert, S; Raboin, L-M; Hervouet, C; Toubi, L; Telismart, H; Garsmeur, O; Rousselle, Y; Pauquet, J; Nibouche, S; Glaszmann, J-C; Hoarau, J-Y; D'Hont, A

2012-09-01

Modern sugarcane cultivars (Saccharum spp., 2n = 100-130) are high polyploid, aneuploid and of interspecific origin. A major gene (Bru1) conferring resistance to brown rust, caused by the fungus Puccinia melanocephala, has been identified in cultivar R570. We analyzed 380 modern cultivars and breeding materials covering the worldwide diversity with 22 molecular markers genetically linked to Bru1 in R570 within a 8.2 cM segment. Our results revealed a strong LD in the Bru1 region and strong associations between most of the markers and rust resistance. Two PCR markers, that flank the Bru1-bearing segment, were found completely associated with one another and only in resistant clones representing efficient molecular diagnostic for Bru1. On this basis, Bru1 was inferred in 86 % of the 194 resistant sugarcane accessions, revealing that it constitutes the main source of brown rust resistance in modern cultivars. Bru1 PCR diagnostic markers should be particularly useful to identify cultivars with potentially alternative sources of resistance to diversify the basis of brown rust resistance in breeding programs.

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.

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.

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.

A comparative study of nitrite reduction by synthetic and biogenic Fe(II-III) hydroxysalts green rusts: Evidence for hydroxyl-nitrite green rust formation as an intermediate reaction product.

Science.gov (United States)

Ona-Nguema, G.; Guerbois, D.; Morin, G.; Zhang, Y.; Noel, V.; Brest, J.

2013-12-01

-GR(Cl) led to the reduction of nitrite ions to ammonium, and that the production of ammonium depended on their Fe(II) content. XRD patterns indicated that both synthetic green rusts were fully oxidized into magnetite during the reaction with nitrite. For biogenic green rusts, the study revealed that both bio-GR(CO3)F and bio-GR(CO3)L were capable of reducing nitrite ions without ammonium production, suggesting the conversion of nitrite ions to nitrogen gas. Moreover, we provided evidence for the first time that the interactions of bio-GR(CO3)F with nitrite led to the formation of an hydroxy-nitrite green rust as a result of the incorporation of nitrite in the interlayer region of bio-GR(CO3)F; such an intercalation of nitrite ions was not observed in experiments with bio-GR(CO3)L. XRD analysis indicated that GR(NO2) was formed as an intermediate reaction product prior to the fully oxidation of GR to ferric oxyhydroxides. [1] Philips S., Laanbroek H. J. and Verstraete W. (2002). Rev. Environ. Sci. Biotechnol. 1, 115-141.

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

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.

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.

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...

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.

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.

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...

16 CFR 23.10 - Misuse of “corrosion proof,” “noncorrosive,” “corrosion resistant,” “rust proof,” “rust resistant...

Science.gov (United States)

2010-01-01

... INDUSTRIES § 23.10 Misuse of “corrosion proof,” “noncorrosive,” “corrosion resistant,” “rust proof,” “rust resistant,” etc. (a) It is unfair or deceptive to: (1) Use the terms “corrosion proof,” “noncorrosive... the product will be immune from rust and other forms of corrosion during the life expectancy of the...

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.

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.

Stem rust (Puccinia graminis ssp. graminicola Urban its hosts and harmfulness in grasses grown for seed

Directory of Open Access Journals (Sweden)

Maria Prończuk

2013-12-01

Full Text Available Stem rust development on four species of grasses was studied in field experiments conducted at Radzików in 1997-2001. Population of Puccinia graminis ssp. graminicola from different hosts was characterised and their harmfulness for grass grown for seed was estimated. The materials for study were ecotypes and strains of Lolium perenne, Festuca rubra, Poa pratensis and Deschampsia caespitosa collected in breeding nursery and cultivars and strains of L.perenne, F.rubra, P.pratensis cultivated for seed. It was found that the changes in environmental conditions during last years influenced earlier occurrence of stem rust on grasses in Poland. All examined species were the host of P.graminis ssp. graminicola, however the period of infection of particular hosts were different. L.perenne and D.caespitosa were infected in early summer but F.rubra and P.pratensis in late summer or in the autumn. Morphological analysis of spores of P.graminis ssp. graminicola have shoved significant differences between populations obtained from L.perenne and D.caespitosa. Some differences were found between populations from F.rubra and P.pratensis also, but they need more study. Every year occurrence of stem rust on L.perenne and D.caespitosa and its relation with spring temperature in Radzików indicated that populations of patogen could overwinter in local turf. Incidental appearance of stem rust on F.rubra and P.pratensis in centre of Poland allowed to suppose that spores of these forms might be transfer by wind from other regions. The investigation revealed that stem rust can be dangerous for L.perenne grown for seed when infection occurs at flowering time. It has been established that infection of F.rubra and P.pratensis in autumn should not be disregarded. Damages of leaves by P.graminis ssp. graminicola substantially limited plant heading in the next year.

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...

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)

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)

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.

Relationship between sugarcane rust severity and soil properties in louisiana.

Science.gov (United States)

Johnson, Richard M; Grisham, Michael P; Richard, Edward P

2007-06-01

ABSTRACT The extent of spatial and temporal variability of sugarcane rust (Puccinia melanocephala) infestation was related to variation in soil properties in five commercial fields of sugarcane (interspecific hybrids of Saccharum spp., cv. LCP 85-384) in southern Louisiana. Sugarcane fields were grid-soil sampled at several intensities and rust ratings were collected at each point over 6 to 7 weeks. Soil properties exhibited significant variability (coefficients of variation = 9 to 70.1%) and were spatially correlated in 39 of 40 cases with a range of spatial correlation varying from 39 to 201 m. Rust ratings were spatially correlated in 32 of 33 cases, with a range varying from 29 to 241 m. Rust ratings were correlated with several soil properties, most notably soil phosphorus (r = 0.40 to 0.81) and soil sulfur (r = 0.36 to 0.68). Multiple linear regression analysis resulted in coefficients of determination that ranged from 0.22 to 0.73, and discriminant analysis further improved the overall predictive ability of rust models. Finally, contour plots of soil properties and rust levels clearly suggested a link between these two parameters. These combined data suggest that sugarcane growers that apply fertilizer in excess of plant requirements will increase the incidence and severity of rust infestations in their fields.

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

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.

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

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)

Genetics of leaf rust-resistant mutant WH 147-LM-1 in hexaploid wheat variety WH 147

International Nuclear Information System (INIS)

Reddy, V.R.K.; Viswanathan, P.

1999-01-01

By applying gamma rays, EMS and their combination in hexaploid wheat variety WH 147, a total of 20 mutants (0.0226%) exhibiting complete leaf rust resistance were isolated from segregating M2 rows.When one of the rust-resistant mutants, WH 147-LM-1 was crossed with the universally susceptible, suggesting that the mutant character is controlled by one dominant gene and one recessive gene.The F2 plants derived by crossing the mutant WH 147-LM with seven near-isogenic wheat lines showed segregation for susceptibility, indicating that the mutant character was indeed generated through induced mutations

Utilization of a major brown rust resistance gene in sugarcane breeding

Science.gov (United States)

Brown rust, caused by Puccinia melanocephala has had devastating effects on sugarcane (Saccharum spp.) breeding programs and on commercial production. The discovery of Bru1, a major gene conferring resistance to brown rust represented a substantial breakthrough and markers for the detection of Bru1 ...

SOME IMPORTANT SHOOT AND STEM FUNGI IN PINE (Pinus spp.) AND FIRS (Abies sp.) IN WESTERN BLACKSEA REGION, TURKEY

OpenAIRE

ÖZKAZANÇ, Nuri Kaan; MADEN, Salih

2013-01-01

This study was carried out to determine fungal diseases of pines and firs observed on the shoots and the stems in the Western Blacksea Region (Karabük, Ulus and Bartın State Forest Enterprises) between the years of 2001–2004. Five different fungi were determined on pines (Pinus sp.) and firs (Abies sp.) by this study. Melampsora pinitorqua and Cronartium flaccidum which cause rust diseases were determined only on pines. Sphaeropsis sapinea and Gremmeniella abietina were determined on pines an...

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,...

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)

Structure and Charge Hopping Dynamics in Green Rust

International Nuclear Information System (INIS)

Wander, Matthew C.; Rosso, Kevin M.; Schoonen, Martin A.

2007-01-01

Green rust is a family of mixed-valent iron phases formed by a number of abiotic and biotic processes under alkaline suboxic conditions. Due to its high Fe2+ content, green rust is a potentially important phase for pollution remediation by serving as a powerful electron donor for reductive transformation. However, mechanisms of oxidation of this material are poorly understood. An essential component of the green rust structure is a mixed-valent brucite-like Fe(OH)2 sheet comprised of a two dimensional network of edge-sharing iron octahedra. Room temperature Mossbauer spectra show a characteristic signature for intermediate valence on the iron atoms in this sheet, indicative of a Fe2+-Fe3+ valence interchange reaction faster than approximately 107s-1. Using Fe(OH)2 as structural analogue for reduced green rust, we performed Hartree-Fock calculations on periodic slab models and cluster representations to determine the structure and hopping mobility of Fe3+ hole polarons in this material, providing a first principles assessment of the Fe2+-Fe3+ valence interchange reaction rate. The calculations show that among three possible symmetry unique iron-to-iron hops within a sheet, a hop to next-nearest neighbors at an intermediate distance of 5.6Angstroms is the fastest. The predicted rate is on the order of 1012 s-1 consistent the Mossbauer-based constraint. All other possibilities, including hopping across interlayer spaces, are predicted to be slower than 107s-1. Collectively, the findings suggest the possibility of hole self-diffusion along sheets as a mechanism for regeneration of lattice Fe2+ sites, consistent with previous experimental observations of edge-inward progressive oxidation of green rust.

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.

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

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....... Due to variable quality of aecial samples DNA extraction was not successful for 40% of the samples. Sequences of EF1α, β-tubulin or ITS were analysed and compared to reference sequences of rust fungi infecting cereals and grasses. The analysis supported the presence of P. graminis s.l., P....... 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...

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.

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...

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.

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.

Inheritance of resistance to orange rust in sugarcane

Science.gov (United States)

Orange rust, caused by Puccinia kuehnii, is an economically important disease in the Florida sugarcane industry. In this study, orange rust reactions of seedlings in progenies originating from 12 crosses between female and male parents with differing resistance to orange rust (three of each categor...

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.

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

Genotyping Sugarcane for the Brown Rust Resistance Locus Bru1 Using Unlabeled Probe Melting

Science.gov (United States)

Brown rust, caused by the fungus Puccinia melanocephala, is a major disease of sugarcane (Saccharum spp.) in Florida, Louisiana, and other sugarcane growing regions. The Bru1 locus has been used as a durable and effective source of resistance, and markers are available to select for the trait. The...

Yellow Rust Resistance in Advanced Lines and Commercial ...

African Journals Online (AJOL)

The objective of this study was to characterize seedling yellow rust resistance in 21 advanced bread wheat lines and 20 cultivars from Ethiopia. Yellow rust infection types (ITs) produced on test wheat lines and cultivars from nine yellow rust races were compared with ITs produced on standard differential lines that differed ...

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

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...

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…

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.

29-34 Yellow Rust Resistance in Advanced Lines and Commercial ...

African Journals Online (AJOL)

rust pathogen. The objective of this study was to characterize seedling yellow rust resistance in 21 advanced bread wheat lines and 20 cultivars from Ethiopia. Yellow rust infection types (ITs) produced on test wheat lines and cultivars from nine yellow rust races were compared with ITs produced on standard differential lines ...

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.

LEAF WHORL INOCULATION METHOD FOR SCREENING SUGARCANE RUST RESISTANCE

Science.gov (United States)

Technical Abstract: Sugarcane rust diseases, brown rust caused by Puccinia melanocephala, and orange rust caused by P. kuehnii, are agronomically important diseases in Florida. Cultivar resistance is the best means of controlling these diseases. Natural infection has been the primary means of asses...

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)

75 FR 57846 - Airworthiness Directives; Robert E. Rust, Jr. Model DeHavilland DH.C1 Chipmunk 21, DH.C1 Chipmunk...

Science.gov (United States)

2010-09-23

... Aircraft Certification Office (ACO), 1701 Columbia Avenue, College Park, Georgia 30337; telephone: (404... Airworthiness Directives; Robert E. Rust, Jr. Model DeHavilland DH.C1 Chipmunk 21, DH.C1 Chipmunk 22, and DH.C1... the Docket Office (phone: 800-647-5527) is Document Management Facility, U.S. Department of...

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.

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

Science.gov (United States)

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

2015-04-01

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

Characterization of the rust formed on weathering steel exposed to Qinghai salt lake atmosphere

International Nuclear Information System (INIS)

Li, Q.X.; Wang, Z.Y.; Han, W.; Han, E.H.

2008-01-01

The product formed on weathering steel exposed to salt lake atmosphere for 12 months was investigated by X-ray diffraction (XRD), infrared transmission spectroscopy (IRS), scanning electron microscopy (SEM), electron probe micro analyzer (EPMA) and electrochemical techniques. The rust was mainly composed of β-FeOOH, Fe 8 (O,OH) 16 Cl 1.3 and a little γ-FeOOH. Amorphous δ-FeOOH was only on skyward surface. The rust layer suppressed anodic reaction and facilitated the cathodic reaction. The very small value of rust resistance R r in this work indicated that the rust had poor protective ability. Cl element was rich in the whole rust layer and played an important role in accelerating the corrosion of weathering steel in salt lake atmosphere

A summary of information on the rust Puccinia psidii Winter (guava rust) with emphasis on means to prevent introduction of additional strains to Hawaii

Science.gov (United States)

Loope, Lloyd

2010-01-01

The neotropical rust fungus Puccinia psidii(P. psidii) was originally described from the host common guava in its native Brazil but has been found since on hosts throughout the myrtle family (Myrtaceae), including a dramatic host jump to nonnative Eucalyptus plantations. Most rust fungi are able to live only on a very narrow range of host species. P. psidii is unusual both for having a broad host range and for the intensity of its damage to susceptible young growth. This rust first got a foothold in the United States in Florida more than three decades ago. The U.S. Department of Agriculture (USDA) has since considered it a nonactionable, nonreportable pest. Hawaii and Florida are the only two states with native species in the myrtle family. Over a period of 30 years, this rust has done little damage to any of the scattered native Myrtaceae in Florida, although the host range of the rust has gradually grown to about 30 mostly nonnative species in the family, apparently because of increasing genetic variety of the rust by repeated introductions. However, Florida’s native Myrtaceae are among the roughly 1,100 neotropical species that are largely resistant to P. psidii. The 3,000 species of non-neotropical Myrtaceae of the Pacific, Australia, Asia, and Africa are expected to prove much more vulnerable to P. psidii. Little is known about the genetics or genetic strains of P. psidii, although existing literature shows that there are numerous strains that have differential ability to infect suites of host plants.

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.

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

International Nuclear Information System (INIS)

Sohail, Y.

2015-01-01

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

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 ...

Detection, breeding, and selection of durable resistance to brown rust in sugarcane

Science.gov (United States)

Brown rust, caused by Puccinia melanocephala, is an important disease of sugarcane in Louisiana. The adaptability of the pathogen has repeatedly resulted in resistant cultivars becoming susceptible once they are widely grown. The frequency of the brown rust resistance gene Bru1 was low in the breedi...

Laboratory, greenhouse and field methods for screening rust-resistant wheat cultivars

International Nuclear Information System (INIS)

Mashaal, S.F.; Kiraly, Z.; Barabas, Z.; Barna, B.; Cereal Research Inst., Szeged, Hungary)

1977-01-01

Detached flag leaf cultures were not suitable for evaluation of stem-rust resistance in our screening programme. On the basis of yield evaluation it was possible to screen out ten stem-rust ''tolerant'' wheat lines in field experiments. Rusted and protected microplots of each line were paired within a replicate. After artificial inoculation, the protected plants were sprayed with fungicides (benomyl plus dithiocarbamate plus copper salt) at weekly intervals until maturation to keep each protected plot rust-free. The thousand-kernel weights of rusted and protected plots were compared. When the thousand-kernel weight of protected plot increased only slightly and the rust reaction type of plants was susceptible in the rusted plot, the line was screened out as putative ''tolerant''. On the basis of three-year field trial ten ''tolerant'' lines were selected. Nine out of ten lines proved to be resistant to two stem-rust races in greenhouse tests in the seedling stage, when resistance was determined on the basis of reduced spore production instead of infection types. Resistance of these seedlings related partly to the reduced number of pustules and partly to a slow rusting character of plants. It seems possible to screen resistant cultivars in the greenhouse by the method outlined in this paper, when resistance is determined on the basis of a reduced number of infection sites and/or by the slow rusting capacity. (author)

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 ...

REVIEW - Advances on molecular studies of the interaction soybean - Asian rust

Directory of Open Access Journals (Sweden)

Aguida Maria Alves Pereira Morales

2012-01-01

Full Text Available Effective management practices are essential for controlling rust outbreaks. The main control methodused is the application of fungicides, which increases substantially the cost of production and is harmful to theenvironment. Prevention is still the best way to avoid more significant losses in soybean yields. Alternatives,such as planting resistant varieties to the fungus, are also important. The use of resistant or tolerant varietiesis the most promising method for controlling Asian soybean rust. Recently, five dominant genes resistant to soybean rust were described: Rpp1, Rpp2, Rpp3, Rpp4 and Rpp5. However, little is known about the molecular interaction among soybean plant and soybean rust and on the molecular pathway triggered by pathogen recognition. Understanding the molecular mechanisms involved in defense responses is of primary importance for planning strategies to control stress and, consequently, to increase plant adaptation to limiting conditions

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.

Molecular Cytogenetic Characterization of two Triticum–Secale–Thinopyrum Trigeneric Hybrids Exhibiting Superior Resistance to Fusarium Head Blight, Leaf Rust, and Stem Rust Race Ug99

Directory of Open Access Journals (Sweden)

Yi Dai

2017-05-01

Full Text Available Fusarium head blight (FHB, leaf rust, and stem rust are the most destructive fungal diseases in current world wheat production. The diploid wheatgrass, Thinopyrum elongatum (Host Dewey (2n = 2x = 14, EE is an excellent source of disease resistance genes. Two new Triticum–Secale–Thinopyrum trigeneric hybrids were derived from a cross between a hexaploid triticale (X Triticosecale Wittmack, 2n = 6x = 42, AABBRR and a hexaploid Triticum trititrigia (2n = 6x = 42, AABBEE, were produced and analyzed using genomic in situ hybridization and molecular markers. The results indicated that line RE21 contained 14 A-chromosomes, 14 B-chromosomes, three pairs of R-chromosomes (4R, 6R, and 7R, and four pairs of E-chromosomes (1E, 2E, 3E, and 5E for a total chromosome number of 2n = 42. Line RE62 contained 14 A-chromosomes, 14 B-chromosomes, six pairs of R-chromosomes, and one pair of translocation chromosomes between chromosome 5R and 5E, for a total chromosome number of 2n = 42. At the seedling and adult growth stages under greenhouse conditions, line RE21 showed high levels of resistance to FHB, leaf rust, and stem rust race Ug99, and line RE62 was highly resistant to leaf rust and stem rust race Ug99. These two lines (RE21 and RE62 display superior disease resistance characteristics and have the potential to be utilized as valuable germplasm sources for future wheat improvement.

Molecular Cytogenetic Characterization of two Triticum-Secale-Thinopyrum Trigeneric Hybrids Exhibiting Superior Resistance to Fusarium Head Blight, Leaf Rust, and Stem Rust Race Ug99.

Science.gov (United States)

Dai, Yi; Duan, Yamei; Liu, Huiping; Chi, Dawn; Cao, Wenguang; Xue, Allen; Gao, Yong; Fedak, George; Chen, Jianmin

2017-01-01

Fusarium head blight (FHB), leaf rust, and stem rust are the most destructive fungal diseases in current world wheat production. The diploid wheatgrass, Thinopyrum elongatum (Host) Dewey (2 n = 2 x = 14, EE) is an excellent source of disease resistance genes. Two new Triticum-Secale-Thinopyrum trigeneric hybrids were derived from a cross between a hexaploid triticale (X Triticosecale Wittmack, 2 n = 6 x = 42, AABBRR) and a hexaploid Triticum trititrigia (2 n = 6 x = 42, AABBEE), were produced and analyzed using genomic in situ hybridization and molecular markers. The results indicated that line RE21 contained 14 A-chromosomes, 14 B-chromosomes, three pairs of R-chromosomes (4R, 6R, and 7R), and four pairs of E-chromosomes (1E, 2E, 3E, and 5E) for a total chromosome number of 2 n = 42. Line RE62 contained 14 A-chromosomes, 14 B-chromosomes, six pairs of R-chromosomes, and one pair of translocation chromosomes between chromosome 5R and 5E, for a total chromosome number of 2 n = 42. At the seedling and adult growth stages under greenhouse conditions, line RE21 showed high levels of resistance to FHB, leaf rust, and stem rust race Ug99, and line RE62 was highly resistant to leaf rust and stem rust race Ug99. These two lines (RE21 and RE62) display superior disease resistance characteristics and have the potential to be utilized as valuable germplasm sources for future wheat improvement.

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

DEFF Research Database (Denmark)

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

giving access to an unprecedented set of data for rust surveys, alternate hosts (barberry), rust pathotypes, trap nurseries and resistant cultivars. Standardized protocols for data collection have permitted the development of a comprehensive data management system, named the Wheat Rust Toolbox....... 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...

Contribution to Kinetics of Formation of White Rust on Galvanized Steel

International Nuclear Information System (INIS)

Han, D. J.; Pyun, Su Il; Hahn, Y. D.

1981-01-01

Kinetics of formation of white rust on galvanized steel coated with various chromating solutions was studied. White rust occurs as a mixture of zinc oxide and zinc hydroxide. White rust formation rate was measured with a salt spray test as related to Cr 3+ ion amount, ratio of Cr 3+ to Cr 6+ ion(by weight) and surface roughness of the chromate film. Incubation time of white rust formation increased as the ratio of Cr 3+ to Cr 6+ ion in the chromate film increased. White rust propagation rate decreased as the amount of Cr 3+ ion increased. Surface roughness had no detectable relationship with incubation time and white rust propagation rate. Experimental results showed that kinetics of white rust formation was as follows: chromate film consists of insoluble Cr 3+ ion and soluble Cr 6+ ion, the latter act: as a corrosion inhibitor. Leaching rate of Cr 6+ ion from the film decreases with an increase of the ratio of Cr 3+ to Cr 6+ ion in the chromate film. When Cr 6+ ion is leached from the film, a bare zine layer is exposed to air and discontinuities occur in the film where white rust formation is initiated. Further white rust formation occurs due to destruction of the chromate film by chlorine ion. It is concluded that two stages of white rust formation are present and can be ascribed to Cr 6+ ion leaching and destruction of the chromate film by chlorine ion

Rusted Designs: The New Apron

OpenAIRE

Swindells, Steve; Burcikova, Mila

2013-01-01

Articulated as a practice of design-couture, conceptualized as a project that seeks a sense \\ud of social engagement through research, design and making of everyday ‘common couture’, \\ud Rusted puts craft action in a very close relation with daily (political) or practical life. Rusted \\ud designs collage pre-used fabric and clothing (found, bought or gifted) with new cloth, thus \\ud using items of fabric and clothing from different times, countries and with variety of social \\ud histories. Th...

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.

Screening for Resistance to Brown Rust of Sugarcane: Use of Bru1 resistance gene prospects and challenges

Science.gov (United States)

Brown rust of sugarcane caused by, Puccinia melanocephala, is a serious problem in the US sugarcane industry. A major resistance gene, Bru1 was identified and methodology for detecting it was developed by French scientists at CIRAD. The majority of the research resulting in the discovery of Bru1 res...

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

African Journals Online (AJOL)

Microsatellite markers were used to differentiate P. triticina and P. striiformis pathotypes. Amplified fragment length polymorphisms (AFLP) were used to differentiate stem rust P. graminis pathotypes. Phylogenetic trees were created for leaf and stem rust pathotypes. Field isolates of leaf, stem and yellow rust were collected ...

Discovery and characterization of two new stem rust resistance genes in Aegilops sharonensis.

Science.gov (United States)

Yu, Guotai; Champouret, Nicolas; Steuernagel, Burkhard; Olivera, Pablo D; Simmons, Jamie; Williams, Cole; Johnson, Ryan; Moscou, Matthew J; Hernández-Pinzón, Inmaculada; Green, Phon; Sela, Hanan; Millet, Eitan; Jones, Jonathan D G; Ward, Eric R; Steffenson, Brian J; Wulff, Brande B H

2017-06-01

We identified two novel wheat stem rust resistance genes, Sr-1644-1Sh and Sr-1644-5Sh in Aegilops sharonensis that are effective against widely virulent African races of the wheat stem rust pathogen. Stem rust is one of the most important diseases of wheat in the world. When single stem rust resistance (Sr) genes are deployed in wheat, they are often rapidly overcome by the pathogen. To this end, we initiated a search for novel sources of resistance in diverse wheat relatives and identified the wild goatgrass species Aegilops sharonesis (Sharon goatgrass) as a rich reservoir of resistance to wheat stem rust. The objectives of this study were to discover and map novel Sr genes in Ae. sharonensis and to explore the possibility of identifying new Sr genes by genome-wide association study (GWAS). We developed two biparental populations between resistant and susceptible accessions of Ae. sharonensis and performed QTL and linkage analysis. In an F 6 recombinant inbred line and an F 2 population, two genes were identified that mapped to the short arm of chromosome 1S sh , designated as Sr-1644-1Sh, and the long arm of chromosome 5S sh , designated as Sr-1644-5Sh. The gene Sr-1644-1Sh confers a high level of resistance to race TTKSK (a member of the Ug99 race group), while the gene Sr-1644-5Sh conditions strong resistance to TRTTF, another widely virulent race found in Yemen. Additionally, GWAS was conducted on 125 diverse Ae. sharonensis accessions for stem rust resistance. The gene Sr-1644-1Sh was detected by GWAS, while Sr-1644-5Sh was not detected, indicating that the effectiveness of GWAS might be affected by marker density, population structure, low allele frequency and other factors.

Genetic and environmental variation in rust frequency on mature mountain birch trees

Energy Technology Data Exchange (ETDEWEB)

Elamo, Pirjo; Saloniemi, Irma; Helander, M.L.; Neuvonen, Seppo [Turku Univ. (Finland). Dept. of Biology) and (Kevo Subarctic Research Inst., Turku (Finland)

2000-07-01

This study investigated genetic and environmental variation in the frequency of birch rust, the most important leaf disease of birch species, The same half-sib families of mature mountain birch trees were studied in two areas corresponding to their natural growing habitats over 3 yrs. The frequency of birch rust was examined both in the field and from detached leaves inoculated in the laboratory. The frequency of birch rust varied among the mountain birch families. However, the heritability of birch rust resistance was found to be fairly low, with the heritability of naturally occurring birch rust varying between 0.27 and 0.41. The frequency of birch rust varied highly between the two study areas and among study years. Nevertheless, the relative frequency of birch rust among tree individuals and tree families remained similar and as a result no notable genotype x environment interaction was observed. The field and in vitro results differed with respect to the ranking of birch families by birch rust resistance.

New Spectral Index for Detecting Wheat Yellow Rust Using Sentinel-2 Multispectral Imagery

Directory of Open Access Journals (Sweden)

Qiong Zheng

2018-03-01

Full Text Available Yellow rust is one of the most destructive diseases for winter wheat and has led to a significant decrease in winter wheat quality and yield. Identifying and monitoring yellow rust is of great importance for guiding agricultural production over large areas. Compared with traditional crop disease discrimination methods, remote sensing technology has proven to be a useful tool for accomplishing such a task at large scale. This study explores the potential of the Sentinel-2 Multispectral Instrument (MSI, a newly launched satellite with refined spatial resolution and three red-edge bands, for discriminating between yellow rust infection severities (i.e., healthy, slight, and severe in winter wheat. The corresponding simulative multispectral bands for the Sentinel-2 sensor were calculated by the sensor’s relative spectral response (RSR function based on the in situ hyperspectral data acquired at the canopy level. Three Sentinel-2 spectral bands, including B4 (Red, B5 (Re1, and B7 (Re3, were found to be sensitive bands using the random forest (RF method. A new multispectral index, the Red Edge Disease Stress Index (REDSI, which consists of these sensitive bands, was proposed to detect yellow rust infection at different severity levels. The overall identification accuracy for REDSI was 84.1% and the kappa coefficient was 0.76. Moreover, REDSI performed better than other commonly used disease spectral indexes for yellow rust discrimination at the canopy scale. The optimal threshold method was adopted for mapping yellow rust infection at regional scales based on realistic Sentinel-2 multispectral image data to further assess REDSI’s ability for yellow rust detection. The overall accuracy was 85.2% and kappa coefficient was 0.67, which was found through validation against a set of field survey data. This study suggests that the Sentinel-2 MSI has the potential for yellow rust discrimination, and the newly proposed REDSI has great robustness and

New Spectral Index for Detecting Wheat Yellow Rust Using Sentinel-2 Multispectral Imagery.

Science.gov (United States)

Zheng, Qiong; Huang, Wenjiang; Cui, Ximin; Shi, Yue; Liu, Linyi

2018-03-15

Yellow rust is one of the most destructive diseases for winter wheat and has led to a significant decrease in winter wheat quality and yield. Identifying and monitoring yellow rust is of great importance for guiding agricultural production over large areas. Compared with traditional crop disease discrimination methods, remote sensing technology has proven to be a useful tool for accomplishing such a task at large scale. This study explores the potential of the Sentinel-2 Multispectral Instrument (MSI), a newly launched satellite with refined spatial resolution and three red-edge bands, for discriminating between yellow rust infection severities (i.e., healthy, slight, and severe) in winter wheat. The corresponding simulative multispectral bands for the Sentinel-2 sensor were calculated by the sensor's relative spectral response (RSR) function based on the in situ hyperspectral data acquired at the canopy level. Three Sentinel-2 spectral bands, including B4 (Red), B5 (Re1), and B7 (Re3), were found to be sensitive bands using the random forest (RF) method. A new multispectral index, the Red Edge Disease Stress Index (REDSI), which consists of these sensitive bands, was proposed to detect yellow rust infection at different severity levels. The overall identification accuracy for REDSI was 84.1% and the kappa coefficient was 0.76. Moreover, REDSI performed better than other commonly used disease spectral indexes for yellow rust discrimination at the canopy scale. The optimal threshold method was adopted for mapping yellow rust infection at regional scales based on realistic Sentinel-2 multispectral image data to further assess REDSI's ability for yellow rust detection. The overall accuracy was 85.2% and kappa coefficient was 0.67, which was found through validation against a set of field survey data. This study suggests that the Sentinel-2 MSI has the potential for yellow rust discrimination, and the newly proposed REDSI has great robustness and generalized ability

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

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

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

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.

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 ...

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

African Journals Online (AJOL)

ACSS

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 ...

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 ...

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...

Incomplete resistance to coffee leaf rust (Hemileia vastatrix)

NARCIS (Netherlands)

Eskes, A.B.

1983-01-01

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

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

Science.gov (United States)

2010-07-30

...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0... direct final rule notified the public of our intention to amend the black stem rust quarantine and...

McGISH identification and phenotypic description of leaf rust and yellow rust resistant partial amphiploids originating from a wheat × Thinopyrum synthetic hybrid cross.

Science.gov (United States)

Kruppa, Klaudia; Türkösi, Edina; Mayer, Marianna; Tóth, Viola; Vida, Gyula; Szakács, Éva; Molnár-Láng, Márta

2016-11-01

A Thinopyrum intermedium × Thinopyrum ponticum synthetic hybrid wheatgrass is an excellent source of leaf and stem rust resistance produced by N.V.Tsitsin. Wheat line Mv9kr1 was crossed with this hybrid (Agropyron glael) in Hungary in order to transfer its advantageous agronomic traits into wheat. As the wheat parent was susceptible to leaf rust, the transfer of resistance was easily recognizable in the progenies. Three different partial amphiploid lines with leaf rust resistance were selected from the wheat/Thinopyrum hybrid derivatives by multicolour genomic in situ hybridization. Chromosome counting on the partial amphiploids revealed 58 chromosomes (18 wheatgrass) in line 194, 56 (14 wheatgrass) in line 195 and 54 (12 wheatgrass) in line 196. The wheat chromosomes present in these lines were identified and the wheatgrass chromosomes were characterized by fluorescence in situ hybridization using the repetitive DNA probes Afa-family, pSc119.2 and pTa71. The 3D wheat chromosome was missing from the lines. Molecular marker analysis showed the presence of the Lr24 leaf rust resistance gene in lines 195 and 196. The morphological traits were evaluated in the field during two consecutive seasons in two different locations.

Genetics and mapping of a new leaf rust resistance gene in Triticum ...

Indian Academy of Sciences (India)

Genetic analysis in F1, F2 and F2.3 families at the seedling stage revealed that leaf rust resistance in Selection G12 is conditioned by a single incompletely dominant gene. The leaf rust resistance gene was mapped to chromosome 3BL with SSR markers Xgwm114 and Xgwm547 flanking the gene at a distance of 28.3 cM ...

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

Science.gov (United States)

2011-01-19

...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0... notified the public of our intention to amend the black stem rust quarantine and regulations by adding four...

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

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.

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...

Incorporation of Monovalent Cations in Sulfate Green Rust

DEFF Research Database (Denmark)

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

2014-01-01

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

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 ...

Molecular tagging of a novel rust resistance gene R(12) in sunflower (Helianthus annuus L.).

Science.gov (United States)

Gong, L; Hulke, B S; Gulya, T J; Markell, S G; Qi, L L

2013-01-01

Sunflower production in North America has recently suffered economic losses in yield and seed quality from sunflower rust (Puccinia helianthi Schwein.) because of the increasing incidence and lack of resistance to new rust races. RHA 464, a newly released sunflower male fertility restorer line, is resistant to both of the most predominant and most virulent rust races identified in the Northern Great Plains of the USA. The gene conditioning rust resistance in RHA 464 originated from wild Helianthus annuus L., but has not been molecularly marked or determined to be independent from other rust loci. The objectives of this study are to identify molecular markers linked to the rust resistance gene and to investigate the allelism of this gene with the unmapped rust resistance genes present in HA-R6, HA-R8 and RHA 397. Virulence phenotypes of seedlings for the F(2) population and F(2:3) families suggested that a single dominant gene confers rust resistance in RHA 464, and this gene was designated as R(12). Bulked segregant analysis identified ten markers polymorphic between resistant and susceptible bulks. In subsequent genetic mapping, the ten markers covered 33.4 cM of genetic distance on linkage group 11 of sunflower. A co-dominant marker CRT275-11 is the closest marker distal to R(12) with a genetic distance of 1.0 cM, while ZVG53, a dominant marker linked in the repulsion phase, is proximal to R(12) with a genetic distance of 9.6 cM. The allelism test demonstrated that R(12) is not allelic to the rust resistance genes in HA-R6, HA-R8 and RHA 397, and it is also not linked to any previously mapped rust resistance genes. Discovery of the R(12) novel rust resistance locus in sunflower and associated markers will potentially support the molecular marker-assisted introgression and pyramiding of R(12) into sunflower breeding lines.

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...

Resistance to rusts (uromyces pisi and u. viciae-fabae) in pea

OpenAIRE

Barilli, Eleonora; Sillero, Josefina C.; Prats, Elena; Rubiales, Diego

2014-01-01

Pea is the second most important food legume crop in the world. Rust is a pea disease widely distributed, particularly in regions with warm, humid weather. Pea rust can be incited by Uromyces viciae-fabae and by U. pisi. U. viciae-fabae prevails in tropical and subtropical regions such as India and China, while U. pisi prevails in temperate regions. Chemical control of rust is possible, but the use of host plant resistance is the most desired means of rust control. In this paper we revise and...

Creation and validation of a simulator for corneal rust ring removal.

Science.gov (United States)

Mednick, Zale; Tabanfar, Reza; Alexander, Ashley; Simpson, Sarah; Baxter, Stephanie

2017-10-01

To create and validate a simulation model for corneal rust ring removal. Rust rings were created on cadaveric eyes with the use of small particles of metal. The eyes were mounted on suction plates at slit lamps and the trainees practiced rust ring removal. An inexperienced cohort of medical students and first year ophthalmology residents (n=11), and an experienced cohort of senior residents and faculty (n=11) removed the rust rings from the eyes with the use of a burr. Rust ring removal was evaluated based on removal time, percentage of rust removed and incidence of corneal perforation. A survey was administered to participants to determine face validity. Time for rust ring removal was longer in the inexperienced group at 187±93 seconds (range of 66-408 seconds), compared to the experienced group at 117±54 seconds (range of 55-240 seconds) (p=0.046). Removal speed was similar between groups, at 4847±4355 pixels/minute and 7206±5181 pixels/minute in the inexperienced and experienced groups, respectively (p=0.26). Removal percentage values were similar between groups, at 61±15% and 69±18% (p=0.38). There were no corneal perforations. 100% (22/22) of survey respondents believed the simulator would be a valuable practice tool, and 89% (17/19) felt the simulation was a valid representation of the clinical correlate. The corneal rust ring simulator presented here is a valid training tool that could be used by early trainees to gain greater comfort level before attempting rust ring removal on a live patient. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

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 ...

Correlation between RUST assessments of fracture healing to structural and biomechanical properties.

Science.gov (United States)

Cooke, Margaret E; Hussein, Amira I; Lybrand, Kyle E; Wulff, Alexander; Simmons, Erin; Choi, Jeffrey H; Litrenta, Jody; Ricci, William M; Nascone, Jason W; O'Toole, Robert V; Morgan, Elise F; Gerstenfeld, Louis C; Tornetta, Paul

2018-03-01

Radiographic Union Score for Tibia (RUST) and modified RUST (mRUST) are radiographic tools for quantitatively evaluating fracture healing using a cortical scoring system. This tool has high intra-class correlation coefficients (ICCs); however, little evidence has evaluated the scores against the physical properties of bone healing. Closed, stabilized fractures were made in the femora of C3H/HeJ male mice (8-12 week-old) of two dietary groups: A control and a phosphate restricted diet group. Micro-computed tomography (µCT) and torsion testing were carried out at post-operative days (POD) 14, 21, 35, and 42 (n = 10-16) per group time-point. Anteroposterior and lateral radiographic views were constructed from the µCT scans and scored by five raters. The raters also indicated if the fracture were healed. ICCs were 0.71 (mRUST) and 0.63 (RUST). Both RUST scores were positively correlated with callus bone mineral density (BMD) (r = 0.85 and 0.80, p RUST scores positively correlated with callus strength (r = 0.35 and 0.26, p RUST ≥10 and had excellent relationship to structural and biomechanical metrics. Effect of delayed healing due to phosphate dietary restrictions was found at later time points with all mechanical properties (p RUST scores (p > 0.318). Clinical relevance of this study is both RUST scores showed high correlation to physical properties of healing and generally distinguished healed vs. non-healed fractures. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:945-953, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

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.

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

Science.gov (United States)

Vaz Patto, Maria Carlota; Rubiales, Diego

2014-01-01

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 (NHR) 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 NHR 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 NHR mechanisms to breed for broad-spectrum resistance to rust in legume species. PMID:25426128

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.

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 ...

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.

Kinetics of structural rust transformation in environments containing chloride and SO2

International Nuclear Information System (INIS)

Rendon, J. L.; Valencia, A.

2003-01-01

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

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

Directory of Open Access Journals (Sweden)

Amanda L. Pendleton

2014-06-01

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

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.

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.

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...

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

Science.gov (United States)

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

Genome-Wide Association Mapping of Stem Rust Resistance in Hordeum vulgare subsp. spontaneum.

Science.gov (United States)

Sallam, Ahmad H; Tyagi, Priyanka; Brown-Guedira, Gina; Muehlbauer, Gary J; Hulse, Alex; Steffenson, Brian J

2017-10-05

Stem rust was one of the most devastating diseases of barley in North America. Through the deployment of cultivars with the resistance gene Rpg1 , losses to stem rust have been minimal over the past 70 yr. However, there exist both domestic (QCCJB) and foreign (TTKSK aka isolate Ug99) pathotypes with virulence for this important gene. To identify new sources of stem rust resistance for barley, we evaluated the Wild Barley Diversity Collection (WBDC) (314 ecogeographically diverse accessions of Hordeum vulgare subsp. spontaneum ) for seedling resistance to four pathotypes (TTKSK, QCCJB, MCCFC, and HKHJC) of the wheat stem rust pathogen ( Puccinia graminis f. sp. tritici , Pgt ) and one isolate (92-MN-90) of the rye stem rust pathogen ( P. graminis f. sp. secalis , Pgs ). Based on a coefficient of infection, the frequency of resistance in the WBDC was low ranging from 0.6% with HKHJC to 19.4% with 92-MN-90. None of the accessions was resistant to all five cultures of P. graminis A genome-wide association study (GWAS) was conducted to map stem rust resistance loci using 50,842 single-nucleotide polymorphic markers generated by genotype-by-sequencing and ordered using the new barley reference genome assembly. After proper accounting for genetic relatedness and structure among accessions, 45 quantitative trait loci were identified for resistance to P. graminis across all seven barley chromosomes. Three novel loci associated with resistance to TTKSK, QCCJB, MCCFC, and 92-MN-90 were identified on chromosomes 5H and 7H, and two novel loci associated with resistance to HKHJC were identified on chromosomes 1H and 3H. These novel alleles will enhance the diversity of resistance available for cultivated barley. Copyright © 2017 Sallam et al.

Métodos de avaliação da ferrugem do álamo e eficiência de fungicidas no seu controle Evaluation method for poplar rust and its fungicide control efficiency

Directory of Open Access Journals (Sweden)

Louise Larissa May De Mio

2008-10-01

Full Text Available A ferrugem do álamo (Melampsora medusae Thuem. causa sérios prejuízos no viveiro, e seu controle é fundamental para a obtenção de muda de boa qualidade. Este trabalho teve como objetivos: i testar a eficiência de fungicidas de contato (mancozebe, cartap e oxicloreto de cobre e sistêmicos (triadimenol, tebuconazole e difenoconazole no controle da ferrugem; ii comparar métodos de avaliação para discriminar a eficiência entre os tratamentos; iii relacionar desfolha com dados de doença; e iv verificar a influência do controle da ferrugem nos parâmetros de crescimento da árvore em viveiro. O experimento foi montado em São Mateus do Sul, PR, delineado inteiramente ao acaso com 10 tratamentos (testemunha, triadimenol, mancozebe, tebuconazole, difenoconazole, cartap, oxicloreto de cobre, triadimenol-mancozebe, tebuconazole-mancozebe e triadimenol aplicados com o dobro do intervalo dos anteriores e 11 repetições. Com parcelas experimentais de 10 m de largura com quatro linhas de plantio (espaçamento entre linhas de 2,5 e entre plantas de 0,50 m, totalizando 110 parcelas com o clone Latorre. Durante dois ciclos consecutivos foram avaliados: o número de pústulas em meia folha, a % visual de doença, a severidade por parcela, a % visual de desfolha, o diâmetro à altura do peito e a altura de plantas ao final do experimento. Os produtos sistêmicos (triadimenol, tebuconazole e difenoconazole aplicados puros ou intercalados com mancozebe foram eficientes no controle da ferrugem, reduzindo o número de pústulas sobre a folha e a desfolha, o que resultou em ganho significativo no volume final das plantas. O mancozebe aplicado isoladamente também reduziu a epidemia e aumentou o volume da árvore em 42%. O produto cúprico proporcionou aumento de volume em 27%. Os métodos de avaliação utilizados diferenciaram dos tratamentos e houve correlação da doença com os danos na cultura.Poplar rust (Melampsora medusae Thuem. causes serious

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.

Rust Layer Formed on Low Carbon Weathering Steels with Different Mn, Ni Contents in Environment Containing Chloride Ions

Directory of Open Access Journals (Sweden)

Gui-qin FU

2016-11-01

Full Text Available The rusting evolution of low carbon weathering steels with different Mn, Ni contents under a simulated environment containing chloride ions has been investigated to clarify the correlation between Mn, Ni and the rust formed on steels. The results show that Mn contents have little impact on corrosion kinetics of experimental steels. Content increase of Ni both enhances the anti-corrosion performance of steel substrate and the rust. Increasing Ni content is beneficial to forming compact rust. Semi-quantitative XRD phase analysis shows that the quantity ratio of α/γ*（α-FeOOH/(γ-FeOOH+Fe3O4 decreases as Mn content increases but it increases as Ni content increases. Ni enhances rust layer stability but Mn content exceeding 1.06 wt.% is disadvantageous for rust layer stability. The content increase of Mn does not significantly alter the parameters of the polarization curve. However, as Ni contents increases, Ecorr has shifted to the positive along with decreased icorr values indicating smaller corrosion rate especially as Ni content increases from 0.42 wt.% to 1.50 wt.%.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12844

Induced mutations in beans and peas for resistance to rust

International Nuclear Information System (INIS)

Fadl, F.A.M.

1983-01-01

Gamma rays and ethyl methanesulphonate (EMS) were applied in a mutation-induction programme for rust resistance in bean and pea. Bean and pea seeds were pre-soaked 2 hours before irradiation with 9, 10 and 12 krad. For chemical mutagen treatments bean and pea seeds were pre-soaked for 8 hours and treated with 0.5 and 1.5% EMS for four hours. M 2 seeds of beans and peas were planted in 1979. Resistant M 2 plants were selected for their rust resistance and other morphological characters. M 3 seeds of selected plants were planted in 1980. In 1980 more seeds of the same varieties of beans and peas were treated with 0.1 and 0.3% EMS with the aim to produce rust-resistant mutants. Seed germination was reduced by gamma rays or EMS. Dwarf, malformed and abnormal plants were noticed. Some resistant M 2 plants selected gave high grain yields. Some were different in morphological characters. In the M 3 of selected plants various other mutant characters appeared, such as different height of plants, early and late flowering, resistance to powdery mildew in peas, altered grain yield, thickness of stem, pod shape and flower colour. (author)

Green rusts synthesis by coprecipitation of Fe II-Fe III ions and mass-balance diagram

Science.gov (United States)

Ruby, Christian; Aïssa, Rabha; Géhin, Antoine; Cortot, Jérôme; Abdelmoula, Mustapha; Génin, Jean-Marie

2006-06-01

A basic solution is progressively added to various mixed Fe II-Fe III solutions. The nature and the relative quantities of the compounds that form can be visualised in a mass-balance diagram. The formation of hydroxysulphate green rust {GR( SO42-)} is preceded by the precipitation of a sulphated ferric basic salt that transforms in a badly ordered ferric oxyhydroxide. Then octahedrally coordinated Fe II species and SO42- anions are adsorbed on the FeOOH surface and GR( SO42-) is formed at the solid/solution interface. By using the same method of preparation, other types of green rust were synthesised, e.g. hydroxycarbonate green rust {GR( CO32-)}. Like other layered double hydroxides, green rusts obey the general chemical formula [ṡ[ṡmHO]x+ with x⩽1/3. Al-substituted hydroxysulphate green rust consists of small hexagonal crystals with a lateral size ˜50 nm, which is significantly smaller than the size of the GR( SO42-) crystals (˜500 nm). To cite this article: C. Ruby et al., C. R. Geoscience 338 (2006).

Synthesis and characterisation of the Fe(II-III) hydroxy-formate green rust

International Nuclear Information System (INIS)

Refait, P.; Abdelmoula, M.; Genin, J.-M. R.; Jeannin, M.

2006-01-01

A new methodology was envisioned in order to prepare green rust compounds build on organic anions that could intervene in microbiologically influenced corrosion processes of iron and steel. The formate ion was chosen as an example. The formation of rust was simulated by the oxidation of aqueous suspensions of Fe(OH) 2 precipitated from Fe(II) lactate and sodium hydroxide, in the presence of sodium formate to promote the formation of the corresponding green rust. The evolution of the precipitate with time was followed by transmission Moessbauer spectroscopy at 15 K. It was observed that the initial hydroxide was transformed into a new GR compound. Its spectrum is composed of three quadrupole doublets, D 1 (δ = 1.28 mm s -1 , Δ = 2.75 mm s -1 ) and D 2 (δ = 1.28 mm s -1 , Δ 2.48 mm s -1 ) that correspond to Fe(II) and D 3 (δ = 0.49 mm s -1 , Δ = 0.37 mm s -1 ) that corresponds to Fe(III). The relative area of D 3 , close to the proportion of Fe(III) in the GR, was found at 28.5 ± 1.5% (∼2/7). Raman spectroscopy confirmed that the intermediate compound was a Fe(II-III) hydroxy-formate, GR(HCOO - ).

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

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...

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

Indian Academy of Sciences (India)

PUNEET INDER TOOR

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 .... infector rows and experimental material with the mixture of uredinospores of Pst ...

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.

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.

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

Science.gov (United States)

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

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.

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

Science.gov (United States)

Oliver, Richard P

2014-11-01

Rust fungi are major pathogens of many annual and perennial crops. Crop protection is largely based on genetic and chemical control. Fungicide resistance is a significant issue that has affected many crop pathogens. Some pathogens have rapidly developed resistance and hence are regarded as high-risk species. Rust fungi have been classified as being low risk, in spite of sharing many relevant features with high-risk pathogens. An examination of the evidence suggests that rust fungi may be wrongly classified as low risk. Of the nine classes of fungicide to which resistance has developed, six are inactive against rusts. The three remaining classes are quinone outside inhibitors (QoIs), demethylation inhibitors (DMIs) and succinate dehydrogenase inhibitors (SDHIs). QoIs have been protected by a recently discovered intron that renders resistant mutants unviable. Low levels of resistance have developed to DMIs, but with limited field significance. Older SDHI fungicides were inactive against rusts. Some of the SDHIs introduced since 2003 are active against rusts, so it may be that insufficient time has elapsed for resistance to develop, especially as SDHIs are generally sold in mixtures with other actives. It would therefore seem prudent to increase the level of vigilance for possible cases of resistance to established and new fungicides in rusts. © 2014 Society of Chemical Industry.

A metric graph satisfying w41=1$w_4^1 = 1$ that cannot be lifted to a curve satisfying dim⁡ (W41=1$\\dim \\;(W_4^1 = 1$

Directory of Open Access Journals (Sweden)

Coppens Marc

2016-01-01

Full Text Available For all integers g ≥ 6 we prove the existence of a metric graph G with w41=1$w_4^1 = 1$ such that G has Clifford index 2 and there is no tropical modification G′ of G such that there exists a finite harmonic morphism of degree 2 from G′ to a metric graph of genus 1. Those examples show that not all dimension theorems on the space classifying special linear systems for curves have immediate translation to the theory of divisors on metric graphs.

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 ...

Localising QTLs for leaf rust resistance and agronomic traits in barley (¤Hordeum vulgare¤ L.)

DEFF Research Database (Denmark)

Kicherer, S.; Backes, G.; Walther, U.

2000-01-01

to leaf rust by means of artificial infection, heading date, plant height and Kernel weight were assessed. For leaf rust resistance, 4 QTLs were localised, that explained 96.1% of the genetic variation. One QTL on chromosome 4H confirmed a position found in another genetic background and one mapped...

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.

Identifying Quantitative Trait Loci (QTLs) and Developing Diagnostic Markers Linked to Orange Rust Resistance in Sugarcane (Saccharum spp.).

Science.gov (United States)

Yang, Xiping; Islam, Md S; Sood, Sushma; Maya, Stephanie; Hanson, Erik A; Comstock, Jack; Wang, Jianping

2018-01-01

Sugarcane ( Saccharum spp.) is an important economic crop, contributing up to 80% of table sugar used in the world and has become a promising feedstock for biofuel production. Sugarcane production has been threatened by many diseases, and fungicide applications for disease control have been opted out for sustainable agriculture. Orange rust is one of the major diseases impacting sugarcane production worldwide. Identifying quantitative trait loci (QTLs) and developing diagnostic markers are valuable for breeding programs to expedite release of superior sugarcane cultivars for disease control. In this study, an F 1 segregating population derived from a cross between two hybrid sugarcane clones, CP95-1039 and CP88-1762, was evaluated for orange rust resistance in replicated trails. Three QTLs controlling orange rust resistance in sugarcane (qORR109, qORR4 and qORR102) were identified for the first time ever, which can explain 58, 12 and 8% of the phenotypic variation, separately. We also characterized 1,574 sugarcane putative resistance ( R ) genes. These sugarcane putative R genes and simple sequence repeats in the QTL intervals were further used to develop diagnostic markers for marker-assisted selection of orange rust resistance. A PCR-based Resistance gene-derived maker, G1 was developed, which showed significant association with orange rust resistance. The putative QTLs and marker developed in this study can be effectively utilized in sugarcane breeding programs to facilitate the selection process, thus contributing to the sustainable agriculture for orange rust disease control.

Leaf and stripe rust resistance among Ethiopian grown wheat ...

African Journals Online (AJOL)

The result indicated that 20 varieties and lines harbor resistance to the leaf rust and 26 to the stripe rust pathotypes showing infection types <2+. Twelve bread wheat varieties and lines (Et-13 A2, HAR 1407 [Tusie], HAR 1775 [Tura], HAR 1920, HAR 2192, HAR 2534, HAR 2536, HAR 2561, HAR 2563 and three durum lines ...

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...

Interacting genes in the pine-fusiform rust forest pathosystem

Science.gov (United States)

H.V. Amerson; T.L. Kubisiak; S.A. Garcia; G.C. Kuhlman; C.D. Nelson; S.E. McKeand; T.J. Mullin; B. Li

2005-01-01

Fusiform rust (FR) disease of pines, caused by Cronartium quercuum f.sp. fusiforme (Cqf), is the most destructive disease in pine plantations of the southern U. S. The NCSU fusiform rust program, in conjunction with the USDA-Forest Service in Saucier, MS and Athens, GA, has research underway to elucidate some of the genetic interactions in this...

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...

Identification of Green Rust in Groundwater

DEFF Research Database (Denmark)

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

2009-01-01

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......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...

Studies on general resistance to stem rust in wheat

International Nuclear Information System (INIS)

Knott, D.R.

1977-01-01

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

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.

The formation of green rust induced by tropical river biofilm components

International Nuclear Information System (INIS)

Jorand, F.; Zegeye, A.; Ghanbaja, J.; Abdelmoula, M.

2011-01-01

In the Sinnamary Estuary (French Guiana), a dense red biofilm grows on flooded surfaces. In order to characterize the iron oxides in this biofilm and to establish the nature of secondary minerals formed after anaerobic incubation, we conducted solid analysis and performed batch incubations. Elemental analysis indicated a major amount of iron as inorganic compartment along with organic matter. Solid analysis showed the presence of two ferric oxides ferrihydrite and lepidocrocite. Bacteria were abundant and represented more than 10 11 cells g -1 of dry weight among which iron reducers were revealed. Optical and electronic microscopy analysis revealed than the bacteria were in close vicinity of the iron oxides. After anaerobic incubations with exogenous electron donors, the biofilm's ferric material was reduced into green rust, a Fe II -Fe III layered double hydroxide. This green rust remained stable for several years. From this study and previous reports, we suggest that ferruginous biofilms should be considered as a favorable location for GR biomineralization when redox conditions and electron donors availability are gathered. - Research highlights: → Characterization of ferruginous biofilm components by solid analysis methods. → Lepidocrocite and ferrihydrite were the main iron oxides. → Anaerobic incubation of biofilm with electron donors produced green rust. → Biofilm components promote the formation of the green rust. → Ferruginous biofilm could contribute to the natural mercury attenuation.

The formation of green rust induced by tropical river biofilm components

Energy Technology Data Exchange (ETDEWEB)

Jorand, F., E-mail: jorand@pharma.uhp-nancy.fr [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France); Zegeye, A. [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France); Ghanbaja, J. [Service Commun de Microscopies Electroniques et Microanalyses X (SCMEM), Nancy-Universite, Bvd des Aiguillettes, BP 239, 54506, Vandoeuvre-les-Nancy (France); Abdelmoula, M. [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France)

2011-06-01

In the Sinnamary Estuary (French Guiana), a dense red biofilm grows on flooded surfaces. In order to characterize the iron oxides in this biofilm and to establish the nature of secondary minerals formed after anaerobic incubation, we conducted solid analysis and performed batch incubations. Elemental analysis indicated a major amount of iron as inorganic compartment along with organic matter. Solid analysis showed the presence of two ferric oxides ferrihydrite and lepidocrocite. Bacteria were abundant and represented more than 10{sup 11} cells g{sup -1} of dry weight among which iron reducers were revealed. Optical and electronic microscopy analysis revealed than the bacteria were in close vicinity of the iron oxides. After anaerobic incubations with exogenous electron donors, the biofilm's ferric material was reduced into green rust, a Fe{sup II}-Fe{sup III} layered double hydroxide. This green rust remained stable for several years. From this study and previous reports, we suggest that ferruginous biofilms should be considered as a favorable location for GR biomineralization when redox conditions and electron donors availability are gathered. - Research highlights: {yields} Characterization of ferruginous biofilm components by solid analysis methods. {yields} Lepidocrocite and ferrihydrite were the main iron oxides. {yields} Anaerobic incubation of biofilm with electron donors produced green rust. {yields} Biofilm components promote the formation of the green rust. {yields} Ferruginous biofilm could contribute to the natural mercury attenuation.

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

Directory of Open Access Journals (Sweden)

Jinita Sthapit Kandel

Full Text Available 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 research was to identify quantitative trait loci (QTL for stripe rust resistance in PI 480035. A spring wheat, "Avocet Susceptible" (AvS, was crossed with PI 480035 to develop a biparental population of 110 recombinant inbred lines (RIL. The population was evaluated in the field in 2013 and 2014 and seedling reactions were examined against three races (PSTv-14, PSTv-37, and PSTv-40 of the pathogen under controlled conditions. The population was genotyped with genotyping-by-sequencing and microsatellite markers across the whole wheat genome. A major QTL, QYr.wrsggl1-1BS was identified on chromosome 1B. The closest flanking markers were Xgwm273, Xgwm11, and Xbarc187 1.01 cM distal to QYr.wrsggl1-1BS, Xcfd59 0.59 cM proximal and XA365 3.19 cM proximal to QYr.wrsggl1-1BS. Another QTL, QYr.wrsggl1-3B, was identified on 3B, which was significant only for PSTv-40 and was not significant in the field, indicating it confers a race-specific resistance. Comparison with markers associated with previously reported Yr genes on 1B (Yr64, Yr65, and YrH52 indicated that QYr.wrsggl1-1BS is potentially a novel stripe rust resistance gene that can be incorporated into modern breeding materials, along with other all-stage and adult-plant resistance genes to develop cultivars that can provide durable resistance.

Differential resistance to stripe rust (Puccinia striiformis) in collections of basin wild rye (Leymus cinereus)

Science.gov (United States)

Frank M. Dugan; Michael J. Cashman; Richard C. Johnson; Meinan Wang; Chen Xianming

2014-01-01

Differential resistance to stripe rust (Puccinia striiformis) in a planting of 111 wild collections of Basin wild rye (Leymus cinereus) was noted 2011-2013. In 2011, rust severity was rated on a scale of 1-9. Much lighter infection in 2012 and 2013 was rated as the number of symptomatic leaves per plant divided by plant circumference (to adjust for plant size). Effect...

Rust resistance evaluation of advanced wheat (triticum aestivum l.) genotypes using pcr-based dna markers

International Nuclear Information System (INIS)

Rahman, S.U.; Younis, M.; Iqbal, M.Z.; Nawaz, M.

2014-01-01

The most effective and environmental friendly approach for the control of wheat rust disease is the use of resistant genotypes. The present study was conducted to explore rust resistance potential of 85 elite wheat genotypes (36 varieties and 49 advanced lines) using various types of DNA markers like STS, SCAR and SSR. DNA markers linked with different genes conferring resistance to rusts (Leaf rust=Lr, Yellow rust=Yr and Stem rust=Sr) were employed in this study. A total of 18 genes, consisting of eleven Lr (lr1, lr10, lr19, lr21, lr28, lr34, lr39, lr46, lr47, lr51 and lr52), four Yr (yr5, yr18, yr26 and yr29) and three Sr genes (sr2, sr29, and sr36) were studied through linked DNA markers. Maximum number of Lr genes was found in 17 advanced lines and 9 varieties, Yr genes in 26 advanced lines and 20 wheat varieties, and Sr genes in 43 advanced lines and 27 varieties. Minimum number of Lr genes was found in advanced line D-97 and variety Kohinoor-83, Yr genes in wheat variety Bwp-97 and Sr genes in 6 advanced lines and 8 varieties. Molecular data revealed that genotypes having same origin, from a specified area showed resistance for similar type of genes. In this study, an average similarity of 84% was recorded among wheat genotypes. Out of 18 loci, 15 were found to be polymorphic. (author)

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

Science.gov (United States)

Bensabra, Hakim; Azzouz, Noureddine

2013-12-01

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

White blister rusts and downy mildews from bajaur agency fata, with some new records from pakistan

International Nuclear Information System (INIS)

Haq, M.A.; Shahzad, S.

2015-01-01

In a species diversity study of Oomycyctes of Bajaur Agency FATA, Pakistan, infection of white blister rusts and downy mildews recorded on three cultivated and four wild plants. Capsella bursa-pastoris showed mixed infection of Albugo candida and Hyaloperonospora parasitica (syn: Peronospora parasitica). Similarly, A. candida and H. brassicae (syn: P. brassicae) parasitized Brassica campestris. Wilsoniana portulacae (syn: Albugo portulacae) and W. occidentalis com. nov. (syn: Albugo occidentalis) recovered from Portulaca oleracea and Spinacia oleracea, respectively. Bremia taraxaci, B. sonchicola and B. saussureae recorded on Taraxicum officinale, Sonchus sp., and Saussurea sp., respectively. All these obligate parasites are new records from Bajaur Agency, while H. parasitica, W. occidentalis, B. taraxaci, and B. saussureae on the mentioned hosts are new records from Pakistan. (author)

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.

Can T1 w/T2 w ratio be used as a myelin-specific measure in subcortical structures? Comparisons between FSE-based T1 w/T2 w ratios, GRASE-based T1 w/T2 w ratios and multi-echo GRASE-based myelin water fractions.

Science.gov (United States)

Uddin, Md Nasir; Figley, Teresa D; Marrie, Ruth Ann; Figley, Chase R

2018-03-01

Given the growing popularity of T 1 -weighted/T 2 -weighted (T 1 w/T 2 w) ratio measurements, the objective of the current study was to evaluate the concordance between T 1 w/T 2 w ratios obtained using conventional fast spin echo (FSE) versus combined gradient and spin echo (GRASE) sequences for T 2 w image acquisition, and to compare the resulting T 1 w/T 2 w ratios with histologically validated myelin water fraction (MWF) measurements in several subcortical brain structures. In order to compare these measurements across a relatively wide range of myelin concentrations, whole-brain T 1 w magnetization prepared rapid acquisition gradient echo (MPRAGE), T 2 w FSE and three-dimensional multi-echo GRASE data were acquired from 10 participants with multiple sclerosis at 3 T. Then, after high-dimensional, non-linear warping, region of interest (ROI) analyses were performed to compare T 1 w/T 2 w ratios and MWF estimates (across participants and brain regions) in 11 bilateral white matter (WM) and four bilateral subcortical grey matter (SGM) structures extracted from the JHU_MNI_SS 'Eve' atlas. Although the GRASE sequence systematically underestimated T 1 w/T 2 w values compared to the FSE sequence (revealed by Bland-Altman and mountain plots), linear regressions across participants and ROIs revealed consistently high correlations between the two methods (r 2 = 0.62 for all ROIs, r 2 = 0.62 for WM structures and r 2 = 0.73 for SGM structures). However, correlations between either FSE-based or GRASE-based T 1 w/T 2 w ratios and MWFs were extremely low in WM structures (FSE-based, r 2 = 0.000020; GRASE-based, r 2 = 0.0014), low across all ROIs (FSE-based, r 2 = 0.053; GRASE-based, r 2 = 0.029) and moderate in SGM structures (FSE-based, r 2 = 0.20; GRASE-based, r 2 = 0.17). Overall, our findings indicated a high degree of correlation (but not equivalence) between FSE-based and GRASE-based T 1 w/T 2 w ratios, and low correlations between T 1 w/T 2 w ratios and MWFs. This

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 ...

Magnetic property based characterization of rust on weathering steels

International Nuclear Information System (INIS)

Mizoguchi, T.; Ishii, Y.; Okada, T.; Kimura, M.; Kihira, H.

2005-01-01

The characterization of rusts on weathering steels is important in understanding the origin of their corrosion resistance. Rust consists of several phases, e.g. α-, β- and γ-FeOOH, which are anti-ferromagnetic with different Neel temperatures. Rust on so-called advanced weathering steel containing 3 wt.% Ni [H. Kihira, A. Usami, K. Tanabe, M. Ito, G. Shigesato, Y. Tomita, T. Kusunoki, T. Tsuzuki, S. Ito, T. Murata, in: Proc. Symp. on Corrosion and Corrosion Control in Saltwater Environments, Honolulu, 1999, The Electrochemical Soc., pp. 127-136] contains in addition a ferrimagnetic spinel phase [M. Kimura, H. Kihira, Y. Ishii, T. Mizoguchi, in: Proc. 13th Asian-Pacific Corrosion Control Conference, Osaka, 2003; M. Kimura, H. Kihira, N. Ohta, M. Hashimoto, T. Senuma, Corros. Sci., this volume; M. Kimura, N. Ohta, H. Kihira, Mater. Trans. JIM, in press]. The nanostructure of real rust cannot be elucidated satisfactorily only with conventional analytical methods such as X-ray diffraction, because of the complex mixture of phases with fine and imperfect crystallites. Because of the short range of the super-exchange coupling between Fe ions in a solid, the magnetic properties can give information on local configurations even in the absence of perfect crystalline coherence. Therefore, the magnetic properties of rust samples were investigated in detail using a Superconducting Quantum Interference Device (SQUID) magnetometer and Moessbauer spectroscopy. SQUID magnetometry is effective to determine the quantity of the ferrimagnetic phase. The temperature dependence of the Moessbauer spectrum gives information about not only the fractions of the phases but also the distribution of grain volume, V, in each phase according to the super-paramagnetic relaxation effect. This approach has been applied to rust of conventional [T. Okada, Y. Ishii, T. Mizoguchi, I. Tamura, Y. Kobayashi, Y. Takagi, S. Suzuki, H. Kihira, M. Ito, A. Usami, K. Tanabe, K. Masuda, Jpn. J. Appl. Phys. 39

Bulked fusiform rust inocula and Fr gene interactions in loblolly pine

Science.gov (United States)

Fikret Isik; Henry Amerson; Saul Garcia; Ross Whetten; Steve. McKeand

2012-01-01

Fusiform rust disease in loblolly (Pinus taeda L.) and slash (Pinus elliottii Engelm. var elliottii) pine plantations in the southern United States causes multi-million dollar annual losses. The disease is endemic to the region. The fusiform rust fungus (Cronartium quercuum sp.

Influence of yellow rust infextion on 32P transport in detached barley leaves

International Nuclear Information System (INIS)

Schubert, J.

1982-01-01

Several barley cultivars (Hordeum vulgare L.) differing in their resistance to yellow rust (Puccinia striiformis West.) were tested for relationships between changes of 32 P transport in detached leaves and resistance to yellow rust disease. Investigation carried out with detached second leaves from plants infected at their first leaf revealed a matter transport in these leaves changed by the infection. Transport was also influenced by inoculation with yellow rust uredospores. In that case rust infection influenced the basipetal transport less strongly in resistent plants than in susceptible ones. Connected with the findings the influence of fungal substances on transport processes is discussed in general. (author)

An overview of sugarcane brown rust in Cuba

Directory of Open Access Journals (Sweden)

María La O

Full Text Available ABSTRACT: Multiple pathogens affect sugarcane, among them Puccinia melanocephala, the causal agent of brown rust. This disease was first reported in Cuba in 1979 when it was responsible for a severe attack on the main sugarcane variety B4362. The aims of the present study were to give an overview of sugarcane brown rust in Cuba and show the current disease situation in the country. A retrospective analysis regard to sugarcane cultivar composition resistant to brown rust in Cuba was carried out. In addition 154 genotypes, including the most used progenitors in the breeding program and commercial varieties were evaluated under natural infection conditions. The identity of P. melanocephala was verified by Polymerase Chain Reaction (PCR and by sequencing the ITS1 region. After the introduction of P. melanocephala into Cuba, the susceptible variety, B4362, was replaced by Ja60-5 which remained resistant until 1998. Since 2002, a varietal policy supported by a governmental resolution establishing that any single cultivar cannot occupy more than 20 % of the production area for each production company, local area and province, has been applied. Out of the genotypes evaluated, 49 showed resistance to the disease and 35 intermediate behavior, while 39 were susceptible and 31, highly susceptible. P. melanocephala was detected by PCR in all symptomatic samples and its identify confirmed by sequencing the ITS1 region. The adopted measurement together with permanent phytosanitary monitoring and commercial release of resistant or intermediate cultivars succeeded in avoiding any new epidemic. Inoculum pressure was reduced, even on susceptible and highly susceptible varieties since, by resolution, they cannot occupy more than 10 % of the planted area.

Selection and evaluation of soybean lines derived from gamma irradiation for rust resistance

International Nuclear Information System (INIS)

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

1983-01-01

In 1979, seeds of 11 soybean cultivars were gamma irradiated with 15 and 30 krad. Treated and control seeds of each cultivar were planted in the rainy season. In the rainy season of 1980, M 3 populations were screened for rust resistance in Nong Hoi Valley and Mae Joe Experiment Station, both in Chiang Main province. The IWGSR rust rating system was used. Based upon the slow growth of rust on soybean plants, 6 and 115 plants were selected from 2,802 control plants and from 28,824 treated plants, respectively. Selected lines were evaluated in Nong Hoi Valley in the rainy season of 1981. Sixteen selections with average good seed yield per plant and low percentage of shrivelled seeds were obtained. Among them, two lines, namely G8586/Line number 81-1-072 and S.J. 4/Line number 81-1-037 gave the higher average seed yield per plant than other lines. They are at present in a preliminary yield trial in Chiang Mai. Chiang Mai. (author)

Reaction of Rust on Some Bread Wheat Varieties in Çukurova Region

OpenAIRE

AY, Hasan

2013-01-01

This study was conducted with 126 varieties of wheat between 2009-2010 years in Adana. There has not been artificially inoculated yellow, leaf and stem rusts. Races of rust in natural were evaluated in both years. Between 2009-2010 this study was conducted in Adana, with 126 varieties of bread wheat. In both years, only the natural environment leaf rust races inoculated for assessments reactions of bread wheat. According to results, 49 bread wheat varieties were found resistant, 6 bread wheat...

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.

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 ...

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.

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)

Identification of Putative Coffee Rust Mycoparasites via Single-Molecule DNA Sequencing of Infected Pustules.

Science.gov (United States)

James, Timothy Y; Marino, John A; Perfecto, Ivette; Vandermeer, John

2016-01-15

The interaction of crop pests with their natural enemies is a fundament to their control. Natural enemies of fungal pathogens of crops are poorly known relative to those of insect pests, despite the diversity of fungal pathogens and their economic importance. Currently, many regions across Latin America are experiencing unprecedented epidemics of coffee rust (Hemileia vastatrix). Identification of natural enemies of coffee rust could aid in developing management strategies or in pinpointing species that could be used for biocontrol. In the present study, we characterized fungal communities associated with coffee rust lesions by single-molecule DNA sequencing of fungal rRNA gene bar codes from leaf discs (≈28 mm(2)) containing rust lesions and control discs with no rust lesions. The leaf disc communities were hyperdiverse in terms of fungi, with up to 69 operational taxonomic units (putative species) per control disc, and the diversity was only slightly reduced in rust-infected discs, with up to 63 putative species. However, geography had a greater influence on the fungal community than whether the disc was infected by coffee rust. Through comparisons between control and rust-infected leaf discs, as well as taxonomic criteria, we identified 15 putative mycoparasitic fungi. These fungi are concentrated in the fungal family Cordycipitaceae and the order Tremellales. These data emphasize the complexity of diverse fungi of unknown ecological function within a leaf that might influence plant disease epidemics or lead to the development of species for biocontrol of fungal disease. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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.

Effectiveness of carboxylic acids from Pichia membranifaciens against coffee rust

Directory of Open Access Journals (Sweden)

Rosa Laura Andrade Melchor

Full Text Available ABSTRACT Coffee rust is a fungal disease that has affected every coffee-producing region in the world. Given that the effectivity of the protectant and systemic fungicides applied routinely to control the spread of the causative agent of the disease (Hemileia vastatrix has gradually diminished, besides are harmful to mammals and ecosystems, the objective of this work was to search for a mixture of harmless natural compounds with the potential to be applied in the field. So, a yeast strain producing a battery of long-chain carboxylic acids (CA with fungicide properties was isolated from soil of coffee crop and identified as Pichia membranifaciens by ITS sequencing. Culture conditions of the yeast were optimized and the CA in the solution were characterized by Gas Chromatography-Mass Spectrometry (GC-MS as ethyl formate (55.5 g L-1, octadecenoic acid (3.5 g L-1, propionic acid (7.2 g L-1, 3-(octadecanoyl-propionic acid (7.2 g L-1 and methyl acetate (8.4 g L-1. Randomized field studies were conducted in three different locations in Chiapas, México. Five treatments were tested including three concentrations of the CA solution (389, 584 and 778 ppm and copper oxychloride (5 000 ppm as conventional control. The initial coffee rust incidence averages varied between sites: Maravillas (3-9%, Santo Domingo (10-16% and Búcaro (16-22%. The treatments of CA solution proved to be effective at slowing down the progress of the rust disease even for the sites where initial incidence was high. Likewise, the CA solution reduced the viability of H. vastatrix spores, as assessed by fluorescence microscopy.

Genetic variability among the brown rust resistant and susceptible genotypes of sugarcane by RAPD technique

Science.gov (United States)

Brown leaf rust in sugarcane is caused by Puccinia melanocephala (Syd. & P. Syd.), which is major cause of cultivar withdrawal. We attempted to analyze the RAPD diversity of two discrete phenotypic classes i.e. rust resistant (R) and rust susceptible (S) of six commercially available sugarcane elite...

A coupled carbonation-rust formation mechanical damage model for steel corrosion in reinforced concrete

International Nuclear Information System (INIS)

Nguyen, Huyen; Bary, B.; L'Hostis, Valerie; DeLarrard, T.

2014-01-01

This paper aims at presenting a strategy to simulate the corrosion of steel reinforcement due to carbonation of concrete in atmospheric environment. We propose a model coupling drying, carbonation, diffusion of oxygen, formation of rust and mechanics to describe these phenomena. The rust layer is assumed to be composed of two sub-layers with different elastic modulus. An unstable layer with a low modulus (from 0.1 to 5 GPa) is located next to the transformed medium, and another more stable one with a higher modulus (from 100 to 150 GPa) at the interface with steel reinforcement. This model is applied to a numerical meso-structure composed of 4 phases: mortar matrix, randomly distributed aggregates, steel rebar and rust layers to underline the effect of aggregates on damage initiation and corresponding crack pattern of concrete cover. (authors)

White pine blister rust in northern ldaho and western Montana: alternatives for integrated management

Science.gov (United States)

Susan K. Hagle; Geral I. McDonald; Eugene A. Norby

1989-01-01

This report comprises a handbook for managing western white pine in northern ldaho and western Montana, under the threat of white pine blister rust. Various sections cover the history of the disease and efforts to combat it, the ecology of the white pine and Ribes, alternate host of the rust, and techniques for evaluating the rust hazard and attenuating it. The authors...

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.

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

Indian Academy of Sciences (India)

tance genes (Lr) and 48 stripe rust resistance genes (Yr) have .... Leaf rust reaction of the parents, wheat – Ae. caudata introgression lines and representative F2 plants developed from the cross: .... segregation ratio, which is otherwise a serious problem with ... Financial assistance was provided by the USDA-ARS under the.

Phylogeny and taxonomy of grass rusts with aecia on Ranunculus and Ficaria

Czech Academy of Sciences Publication Activity Database

Hrabětová, M.; Kolařík, Miroslav; Marková, J.

2015-01-01

Roč. 14, č. 3 (2015) ISSN 1617-416X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : Rust fungi * Pucciniales * Puccinia Subject RIV: EE - Microbiology, Virology Impact factor: 1.572, year: 2015

Mechanical properties of the rust layer induced by impressed current method in reinforced mortar

International Nuclear Information System (INIS)

Care, S.; Nguyen, Q.T.; L'Hostis, V.; Berthaud, Y.

2008-01-01

This paper describes the mechanical effects of rust layer formed in reinforced mortar through accelerated tests of corrosion. The morphological and physico-chemical properties (composition, structures) of the corrosion system were characterized at different stages by using optical microscope and scanning electron microscope coupled with energy dispersive spectroscopy. The corrosion pattern was mainly characterized by a rust layer confined at the interface between the steel and the mortar. Expansion coefficient of rust products was determined from the rust thickness and the Faraday's law. Furthermore, in order to understand the mechanical effects of corrosion on the damage of mortar, displacement field measurements were obtained by using digital image correlation. An analytical model (hollow cylinder subjected to inner and outer pressures) was used with a set of experimental data to deduce the time of cracking and the order of magnitude of the mechanical properties of the rust layer

Influence of yellow rust infection on /sup 32/P transport in detached barley leaves

Energy Technology Data Exchange (ETDEWEB)

Schubert, J. (Akademie der Landwirtschaftswissenschaften der DDR, Aschersleben. Inst. fuer Phytopathologie)

1982-01-01

Several barley cultivars (Hordeum vulgare L.) differing in their resistance to yellow rust (Puccinia striiformis West.) were tested for relationships between changes of /sup 32/P transport in detached leaves and resistance to yellow rust disease. Investigation carried out with detached second leaves from plants infected at their first leaf revealed a matter transport in these leaves changed by the infection. Transport was also influenced by inoculation with yellow rust uredospores. In that case rust infection influenced the basipetal transport less strongly in resistent plants than in susceptible ones. Connected with the findings the influence of fungal substances on transport processes is discussed in general.

Detection of wheat stem rust race RRTTF in Ecuador in 2016

Science.gov (United States)

Wheat stem rust is a devastating disease that has incited numerous severe epidemics resulting in extreme yield losses over the past century. Stem rust infection in plots of wheat line UC11075, known to carry the Sr38 resistance gene, was severe in February 2016 in a nursery at the Instituto Nacional...

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...

MICROCOSM STUDY OF DEGRADATION OF CHLORINATED SOLVENTS ON SYNTHETIC GREEN RUST MINERALS

Science.gov (United States)

Green rust minerals contain ferrous ion in their structure that can potentially serve as a chemical reductant for degradation of chlorinated solvents. Green rusts are found in zerovalent iron based permeable reactive barriers and in certain soil and sediments. Some previous labor...

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.

Enhanced resistance to stripe rust disease in transgenic wheat expressing the rice chitinase gene RC24.

Science.gov (United States)

Huang, Xuan; Wang, Jian; Du, Zhen; Zhang, Chen; Li, Lan; Xu, Ziqin

2013-10-01

Stripe rust is a devastating fungal disease of wheat worldwide which is primarily caused by Puccinia striiformis f. sp tritici. Transgenic wheat (Triticum aestivum L.) expressing rice class chitinase gene RC24 were developed by particle bombardment of immature embryos and tested for resistance to Puccinia striiformis f.sp tritici. under greenhouse and field conditions. Putative transformants were selected on kanamycin-containing media. Polymease chain reaction indicated that RC24 was transferred into 17 transformants obtained from bombardment of 1,684 immature embryos. Integration of RC24 was confirmed by Southern blot with a RC24-labeled probe and expression of RC24 was verified by RT-PCR. Nine transgenic T1 lines exhibited enhanced resistance to stripe rust infection with lines XN8 and BF4 showing the highest level of resistance. Southern blot hybridization confirmed the stable inheritance of RC24 in transgenic T1 plants. Resistance to stripe rust in transgenic T2 and T3 XN8 and BF4 plants was confirmed over two consecutive years in the field. Increased yield (27-36 %) was recorded for transgenic T2 and T3 XN8 and BF4 plants compared to controls. These results suggest that rice class I chitinase RC24 can be used to engineer stripe rust resistance in wheat.

Effects of rust in the crack face on crack detection based on Sonic-IR method

International Nuclear Information System (INIS)

Harai, Y.; Izumi, Y.; Tanabe, H.; Takamatsu, T.; Sakagami, T.

2015-01-01

Sonic-IR, which is based on the thermographic detection of the temperature rise due to frictional heating at the defect faces under ultrasonic excitation, has an advantage in the detection of closed and small defects. However, this method has a lot of nuclear factors relating to heat generation. In this study, effects of rust in the crack faces on the crack detection based on the sonic-IR method is experimentally investigated by using crack specimens. The heat generation by ultrasonic excitation was observed regularly during rust accelerated test using original device. The distribution of temperature change around the crack was changed with the progress of rust. This change in heat generation, it believed to be due to change in the contact state of the crack surface due to rust. As a result, it was found that heat generation by ultrasonic excitation is affected by rust in the crack faces. And it was also found that crack detection can be conducted by sonic-IR even if rust was generated in the crack faces. (author)

Quantitative characterization of the atomic-scale structure of oxyhydroxides in rusts formed on steel surfaces

International Nuclear Information System (INIS)

Saito, M.; Suzuki, S.; Kimura, M.; Suzuki, T.; Kihira, H.; Waseda, Y.

2005-01-01

Quantitative X-ray structural analysis coupled with anomalous X-ray scattering has been used for characterizing the atomic-scale structure of rust formed on steel surfaces. Samples were prepared from rust layers formed on the surfaces of two commercial steels. X-ray scattered intensity profiles of the two samples showed that the rusts consisted mainly of two types of ferric oxyhydroxide, α-FeOOH and γ-FeOOH. The amounts of these rust components and the realistic atomic arrangements in the components were estimated by fitting both the ordinary and the environmental interference functions with a model structure calculated using the reverse Monte Carlo simulation technique. The two rust components were found to be the network structure formed by FeO 6 octahedral units, the network structure itself deviating from the ideal case. The present results also suggest that the structural analysis method using anomalous X-ray scattering and the reverse Monte Carlo technique is very successful in determining the atomic-scale structure of rusts formed on the steel surfaces

Induced mutations for rust resistance in bread wheat

International Nuclear Information System (INIS)

Sawhney, R.N.

1989-01-01

Full text: Seeds of variety ''Lalbahadur'' were treated with 0.04% NMH. M 2 plants were inoculated with a mixture of pathotypes of each of the 3 Puccinia species (P. graminis, P. recondita, P. striiformis). Plants with simultaneous resistance to all 3 rusts were selected. Repeated testing in subsequent generations confirmed the resistance. The mutant lines are morphologically similar to the parent cultivar and therefore could be used as components of a multiline variety. Comparison of variety pattern against the Indian pathotypes of rusts suggests that the mutant genes are different from the ones known already in bread wheat. (author)

Defeating the Warrior: genetic architecture of triticale resistance against a novel aggressive yellow rust race.

Science.gov (United States)

Losert, Dominik; Maurer, Hans Peter; Leiser, Willmar L; Würschum, Tobias

2017-04-01

Genome-wide association mapping of resistance against the novel, aggressive 'Warrior' race of yellow rust in triticale revealed a genetic architecture with some medium-effect QTL and a quantitative component, which in combination confer high levels of resistance on both leaves and ears. Yellow rust is an important destructive fungal disease in small grain cereals and the exotic 'Warrior' race has recently conquered Europe. The aim of this study was to investigate the genetic architecture of yellow rust resistance in hexaploid winter triticale as the basis for a successful resistance breeding. To this end, a diverse panel of 919 genotypes was evaluated for yellow rust infection on leaves and ears in multi-location field trials and genotyped by genotyping-by-sequencing as well as for known Yr resistance loci. Genome-wide association mapping identified ten quantitative trait loci (QTL) for yellow rust resistance on the leaves and seven of these also for ear resistance. The total genotypic variance explained by the QTL amounted to 44.0% for leaf and 26.0% for ear resistance. The same three medium-effect QTL were identified for both traits on chromosomes 1B, 2B, and 7B. Interestingly, plants pyramiding the resistance allele of all three medium-effect QTL were generally most resistant, but constitute less than 5% of the investigated triticale breeding material. Nevertheless, a genome-wide prediction yielded a higher predictive ability than prediction based on these three QTL. Taken together, our results show that yellow rust resistance in winter triticale is genetically complex, including both medium-effect QTL as well as a quantitative resistance component. Resistance to the novel 'Warrior' race of this fungal pathogen is consequently best achieved by recurrent selection in the field based on identified resistant lines and can potentially be assisted by genomic approaches.

40 CFR Table 1 to Subpart W of... - General Provisions Applicability to Subpart W

Science.gov (United States)

2010-07-01

... Subpart W 1 Table 1 to Subpart W of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Polyamides Production Pt. 63, Subpt. W, Table 1 Table 1 to Subpart W of Part 63—General Provisions Applicability to Subpart W Reference Applies to subpart W BLR WSR WSR alternative standard, and BLR equipment...

Strategies for managing whitebark pine in the presence of white pine blister rust [Chapter 17

Science.gov (United States)

Raymond J. Hoff; Dennis E. Ferguson; Geral I. McDonald; Robert E. Keane

2001-01-01

Whitebark pine (Pinus albicaulis) is one of many North American white pine species (Pinus subgenus Strobus) susceptible to the fungal disease white pine blister rust (Cronartium ribicola). Blister rust has caused severe mortality (often reaching nearly 100 percent) in many stands of white bark pine north of 45° latitude in western North America. The rust is slowly...

Survey the Effect of Mycorrhiza and Azospirillum of Wheat Cultivars Resistance in Yellow Rust

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M. Jiriaie

2017-01-01

-levels (non-inoculated seeds and inoculated seed and wheat cultivars in three levels, Chamran (bread wheat, Dena and Behrang (durum wheat varieties. In this experiment evaluated, to yellow rust disease, the intensity of infection, the average coefficient of infection, type of infection and area under disease progress curve (AUDPC. Infection type and disease severity were also recorded at flag leaf stage using modified Cobb’s scale. First symptoms of yellow rust were observed in middle January of 2013. Analysis of variance was performed using PROC ANOVA of SAS (version 9.1.3, 2004The comparison of the means was done by Duncan test at a probability level of 5 percent. Results and Discussion: Survey on the resistance to yellow rust in wheat cultivars treated with Mycorrhiza and Azospirillum showed that seed inoculation with Azospirillum traits reduced between 10 percent to 13 percent and the use strains of Mycorrhiza fungi intensity of infection 45-51 percent, the average coefficient of infection and AUDPC 74-85 percent respectively for G. intraradices and G. mosseae strains have been reduced compared with control and Chamran cultivar between 40-70 percent showed more Sensitivity to disease from durum varieties. Generally, the lowest of infection intensity (18.33 was obtained from inoculation of C.V Dena seeds with Azospirillum and G. mosseae strain. According to the result, we found yellow rust in all experiment field also the incidence varied between 10-70 percent. Therefore, it is concluded that, given the climatic conditions favorable to the spread of yellow rust, the incidence of yellow rust in the region that have a high degree of pathogenicity. In general the results of this test, mycorrhiza application has a significant role in enhancing wheat resistance to yellow rust. The seed inoculation with Azospirillum although did not have significant role in disease control, but increased at an acceptable level resistance to wheat rust. But the important point was the combined

Low average blister-rust infection rates may mean high control costs

Science.gov (United States)

Robert Marty

1965-01-01

The Northeastern Forest Experiment Station, in cooperation with Federal and State forest-pest-control agencies, undertook a survey of blister-rust infection rates in the white pine region of the East during 1962 and 1963. Those engaged in blister-rust-control activities will not be surprised at the survey's results. We found that infection rates were significantly...

Studies of the genetics of inheritance of stem rust resistance in ...

African Journals Online (AJOL)

Five resistant wheat lines (KSL-2, KSL-3, KSL-5, KSL-12 and KSL-19) which were resistant in tests during 2008, 2009 and 2010 were used as parents in crosses with stem rust susceptible line CACUKE to develop genetic populations for determining the inheritance of resistance to stem rust. F3 populations were evaluated ...

The calibration of the WISE W1 and W2 Tully-Fisher relation

International Nuclear Information System (INIS)

Neill, J. D.; Seibert, Mark; Scowcroft, Victoria; Tully, R. Brent; Courtois, Hélène; Sorce, Jenny G.; Jarrett, T. H.; Masci, Frank J.

2014-01-01

In order to explore local large-scale structures and velocity fields, accurate galaxy distance measures are needed. We now extend the well-tested recipe for calibrating the correlation between galaxy rotation rates and luminosities—capable of providing such distance measures—to the all-sky, space-based imaging data from the Wide-field Infrared Survey Explorer (WISE) W1 (3.4 μm) and W2 (4.6 μm) filters. We find a correlation of line width to absolute magnitude (known as the Tully-Fisher relation, TFR) of M W1 b,i,k,a =−20.35−9.56(log W mx i −2.5) (0.54 mag rms) and M W2 b,i,k,a =−19.76−9.74(log W mx i −2.5) (0.56 mag rms) from 310 galaxies in 13 clusters. We update the I-band TFR using a sample 9% larger than in Tully and Courtois. We derive M I b,i,k =−21.34−8.95(log W mx i −2.5) (0.46 mag rms). The WISE TFRs show evidence of curvature. Quadratic fits give M W1 b,i,k,a =−20.48−8.36(log W mx i −2.5)+3.60(log W mx i −2.5) 2 (0.52 mag rms) and M W2 b,i,k,a =−19.91−8.40(log W mx i −2.5)+4.32(log W mx i −2.5) 2 (0.55 mag rms). We apply an I-band –WISE color correction to lower the scatter and derive M C W1 =−20.22−9.12(log W mx i −2.5) and M C W2 =−19.63−9.11(log W mx i −2.5) (both 0.46 mag rms). Using our three independent TFRs (W1 curved, W2 curved, and I band), we calibrate the UNION2 Type Ia supernova sample distance scale and derive H 0 = 74.4 ± 1.4(stat) ± 2.4(sys) km s –1 Mpc –1 with 4% total error.

Determining yield loss caused by brown rust in production fields of sugarcane

Science.gov (United States)

Infections of Puccinia melanocephala, the causal agent of brown rust, appear on Louisiana sugarcane in the spring. Disease expression is usually limited to 2 to 3 months until temperatures exceed those favorable for spore production. The affected sugarcane is harvested 4 to 6 months after rust sympt...

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.

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

Directory of Open Access Journals (Sweden)

Duli Zhao

2015-07-01

Full Text Available Sugarcane (Saccharum spp. brown rust (caused by Puccinia melanocephala Syd. & P. Syd. was first reported in the United States in 1978 and is still one of the great challenges for sugarcane production. A better understanding of sugarcane genotypic variation in response to brown rust will help optimize breeding and selection strategies for disease resistance. Brown rust ratings were scaled from non-infection (0 to severe infection (4 with intervals of 0.5 and routinely recorded for genotypes in the first clonal selection stage of the Canal Point sugarcane breeding program in Florida. Data were collected from 14,272 and 12,661 genotypes and replicated check cultivars in 2012 and 2013, respectively. Mean rust rating, % infection, and severity in each family and progeny of female parent were determined, and their coefficients of variation (CV within and among families (females were estimated. Considerable variation exists in rust ratings among families or females. The families and female parents with high susceptibility or resistance to brown rust were identified and ranked. The findings of this study can help scientists to evaluate sugarcane crosses and parents for brown rust disease, to use desirable parents for crossing, and to improve genetic resistance to brown rust in breeding programs.

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 ...

Pushing the boundaries of resistance: insights from Brachypodium-rust interactions

OpenAIRE

Figueroa, Melania; Castell-Miller, Claudia V.; Li, Feng; Hulbert, Scot H.; Bradeen, James M.

2015-01-01

The implications of global population growth urge transformation of current food and bioenergy production systems to sustainability. Members of the family Poaceae are of particular importance both in food security and for their applications as biofuel substrates. For centuries, rust fungi have threatened the production of valuable crops such as wheat, barley, oat, and other small grains; similarly, biofuel crops can also be susceptible to these pathogens. Emerging rust pathogenic races with i...

A study of the evolution of rust on Mo–Cu-bearing fire-resistant steel submitted to simulated atmospheric corrosion

International Nuclear Information System (INIS)

Hao Long; Zhang Sixun; Dong Junhua; Ke Wei

2012-01-01

Highlights: ► The rusting evolution of a Mo–Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated. ► The rusting evolution of the steel is related to the rust composition, structure, and electrochemical characteristics. ► Increased content of α-FeOOH and decreased γ-FeOOH and Fe 3 O 4 indicate the enhanced resistance of the rust. ► Mo and Cu are involved in the formation of molybdate and Cu(I)-bearing compounds in the rust. - Abstract: The corrosion evolution of a Mo–Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated by corrosion weight gain, XRD, EPMA, XPS, and polarization curves. The results indicate that the corrosion kinetics is closely related to the rust composition and electrochemical properties. As the corrosion proceeds, the relative content of γ-FeOOH and Fe 3 O 4 decreases and α-FeOOH increases, and the rust layer becomes compact and adherent to steel substrate. Molybdenum and copper enrich in the inner rust layer, especially at the bottom of the corrosion nest, forming non-soluble molybdate and Cu(I)-bearing compounds responsible for enhanced corrosion resistance of the rust layer.

Resistance of some early mutant lines of soybean to rust fungus (Phakospora pachyrhizi Syd)

International Nuclear Information System (INIS)

Ratma, Rivaie

1984-01-01

A trial for resistance to rust fungus (Phakospora pachyrhizi Syd.) was conducted on 11 early mutant lines of soybean M6 (derived from Orba variety with a dose of 0.4 kGy of Co-60) at Citayam Experimental Station, Bogor, in the wet season of 80/81. Based on IWGSR rating system, soybean mutant lines number M6/40/6 was moderately susceptible to rust fungus (Phakospora pachyrhizi Syd). While 10 other soybean mutant lines M6/40/1, M6/40/2, M6/40/3, M6/40/4, M6/40/5, M6/40/7, M6/40/8, M6/40/9, M6/40/10 and M6/40/11 were susceptible to rust fungus. Significant differences in yield were observed between the early mutant lines M6/40/6 (moderate susceptible), 10 other mutant lines (susceptible) and ringgit variety (susceptible). However, a significant lower yield was produced by those mutant lines compared with the yield of orba variety. (author)

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

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

Science.gov (United States)

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

2005-10-01

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

Long-term changes in fusiform rust incidence in the southeastern United States

Science.gov (United States)

KaDonna C. Randolph; Ellis B. Cowling; Dale A. Starkey

2015-01-01

Fusiform rust is the most devastating disease of slash pine (Pinus elliottii) and loblolly pine (Pinus taeda) in the southeastern United States. Since the 1970s, the USDA Forest Service Forest Inventory and Analysis (FIA) Program has assessed fusiform rust incidence on its network of ground plots in 13 states across the...

Pushing the boundaries of resistance: insights from Brachypodium-rust interactions

Directory of Open Access Journals (Sweden)

Melania eFigueroa

2015-07-01

Full Text Available The implications of global population growth urge transformation of current food and bioenergy production systems to sustainability. Members of the family Poaceae are of particular importance both in food security and for their applications as biofuel substrates. For centuries, rust fungi have threatened the production of valuable crops such as wheat, barley, oat and other small grains; similarly, biofuel crops can also be susceptible to these pathogens. Emerging rust pathogenic races with increased virulence and recurrent rust epidemics around the world point out the vulnerability of monocultures. Basic research in plant immunity, especially in model plants, can make contributions to understanding plant resistance mechanisms and improve disease management strategies. The development of the grass Brachypodium distachyon as a genetically tractable model for monocots, especially temperate cereals and grasses, offers the possibility to overcome the experimental challenges presented by the genetic and genomic complexities of economically valuable crop plants. The numerous resources and tools available in Brachypodium have opened new doors to investigate the underlying molecular and genetic bases of plant-microbe interactions in grasses and evidence demonstrating the applicability and advantages of working with B. distachyon is increasing. Importantly, several interactions between B. distachyon and devastating plant pathogens, such rust fungi, have been examined in the context of non-host resistance. Here, we discuss the use of B. distachyon in these various pathosystems. Exploiting B. distachyon to understand the mechanisms underpinning disease resistance to non-adapted rust fungi may provide effective and durable approaches to fend off these pathogens. The close phylogenetic relationship among Brachypodium spp. and grasses with industrial and agronomic value support harnessing this model plant to improve cropping systems and encourage its use in

Waste management regroups units into Rust International

International Nuclear Information System (INIS)

Kirschner, E.

1992-01-01

Three Waste Management (Oak Brook, IL) subsidiaries have proposed merging units from Chemical Waste Management (CWM) and Wheelabrator Technologies with the Brand Companies (Park Ridge, IL). Waste Management says the new company, to be called Rust International, will become one of the US's largest environmental consulting and infrastructure organizations and will include design and construction services. Waste Management expects the merged company's 1993 revenues to reach $1.8 billion. It will be based in Birmingham, AL and have 12,000 employees

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.

[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.

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

Directory of Open Access Journals (Sweden)

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.

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...

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 ...

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.

Control of Fe(O,OH)6 nano-network structures of rust for high atmospheric-corrosion resistance

International Nuclear Information System (INIS)

Kimura, Masao; Kihira, Hiroshi; Ohta, Noriaki; Hashimoto, Misao; Senuma, Takehide

2005-01-01

A new-type of weathering steel containing 3.0 mass% Ni and 0.4 mass% Cu ('advanced weathering steel') exhibits good atmospheric-corrosion resistance in an atmosphere containing relatively high air-born salinity. Here, we show that the high performance was successfully achieved by controlling Fe(O,OH) 6 nano-network structures of rust formed on their surfaces. A novel technique using synchrotron radiation has been developed for the in situ observation of rust-formation during wet-dry cycles. It has been revealed that the evolution of Fe(O,OH) 6 nano-network structures of rust formed on the advanced weathering steel was more unique than those of conventional weathering steel and mild steel. At an early stage of reaction, Fe 2 NiO 4 and CuO phases precipitate, which provide sites for the nucleation of the Fe(O,OH) 6 nano-network resulting in the formation of rust composed of fine and dense-packed grains. The existence of Fe 2 NiO 4 in the nano-network changes the ion-exchanging properties of rust from anion to cation selective. Then, the rust on the advanced weathering steel 'breathes out' chloride ions from the rust/steel interface, and protects steel for more than a century by reducing the life cycle maintenance cost in an environment-friendly manner

In situ hybridization for the detection of rust fungi in paraffin embedded plant tissue sections.

Science.gov (United States)

Ellison, Mitchell A; McMahon, Michael B; Bonde, Morris R; Palmer, Cristi L; Luster, Douglas G

2016-01-01

Rust fungi are obligate pathogens with multiple life stages often including different spore types and multiple plant hosts. While individual rust pathogens are often associated with specific plants, a wide range of plant species are infected with rust fungi. To study the interactions between these important pathogenic fungi and their host plants, one must be able to differentiate fungal tissue from plant tissue. This can be accomplished using the In situ hybridization (ISH) protocol described here. To validate reproducibility using the ISH protocol, samples of Chrysanthemum × morifolium infected with Puccinia horiana, Gladiolus × hortulanus infected with Uromyces transversalis and Glycine max infected with Phakopsora pachyrhizi were tested alongside uninfected leaf tissue samples. The results of these tests show that this technique clearly distinguishes between rust pathogens and their respective host plant tissues. This ISH protocol is applicable to rust fungi and potentially other plant pathogenic fungi as well. It has been shown here that this protocol can be applied to pathogens from different genera of rust fungi with no background staining of plant tissue. We encourage the use of this protocol for the study of plant pathogenic fungi in paraffin embedded sections of host plant tissue.

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)

White Matter Fiber-based Analysis of T1w/T2w Ratio Map.

Science.gov (United States)

Chen, Haiwei; Budin, Francois; Noel, Jean; Prieto, Juan Carlos; Gilmore, John; Rasmussen, Jerod; Wadhwa, Pathik D; Entringer, Sonja; Buss, Claudia; Styner, Martin

2017-02-01

To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development.

White matter fiber-based analysis of T1w/T2w ratio map

Science.gov (United States)

Chen, Haiwei; Budin, Francois; Noel, Jean; Prieto, Juan Carlos; Gilmore, John; Rasmussen, Jerod; Wadhwa, Pathik D.; Entringer, Sonja; Buss, Claudia; Styner, Martin

2017-02-01

Purpose: To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. Background: The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. Methods: We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. Results: We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development.

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...

Formation of the Fe(II)-Fe(III) hydroxysulphate green rust during marine corrosion of steel

International Nuclear Information System (INIS)

Refait, Ph.; Memet, J.-B.; Bon, C.; Sabot, R.; Genin, J.-M.R.

2003-01-01

Rust layers formed on steel sheet piles immersed 1 m above the mud line for 25 years were analysed by Raman spectroscopy, scanning electron microscopy and elemental X-ray mappings (Fe, S, O). They consist of three main strata, the inner one mainly composed of magnetite, the intermediate one of iron(III) oxyhydroxides and the outer one of hydroxysulphate green rust GR(SO 4 2- ). Simulations of GRs formation in solutions having large [Cl - ]/[SO 4 2- ] ratios revealed that the hydroxysulphate GR(SO 4 2- ) was obtained instead of the hydroxychloride GR(Cl - ), as demonstrated by X-ray diffraction and transmission Moessbauer spectroscopy analyses. Measurements of the [S], [Fe] and [Cl] concentrations allowed us to establish that GR(SO 4 2- ) formed along with a drastic impoverishment of the solution in sulphate ions; the [Cl - ]/[SO 4 2- ] ratio increased from 12 to 240. The GR, acting like a 'sulphate pump', may favour the colonisation of the rust layers by sulphate reducing bacteria

Abnormal germling development by brown rust and powdery mildew on cer barley mutants

NARCIS (Netherlands)

Rubiales, D.; Ramirez, M.C.; Carver, T.L.W.; Niks, R.E.

2001-01-01

The barley leaf rust fungus forms appressoria over host leaf stomata and penetrates via the stomatal pore. High levels of avoidance to leaf rust fungi have been described in some wild accessions of Hordeum species where a prominent wax layer on the stomata inhibits triggering of fungal appressorium

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.

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.

Rust formed on cannons of XVIII century under two environment conditions

International Nuclear Information System (INIS)

Cindra Fonseca, M.P.; Bastos, I.N.; Caytuero, A.; Baggio Saitovitch, E.M.

2007-01-01

The corrosion products of two ancient cannons exposed to atmospheric corrosion were analysed by X-ray powder diffraction, transmission Moessbauer spectroscopy and scanning electron microscopy (SEM). After almost three centuries exposed in marine environment one of them was moved to a rural region and was maintained in this environment for approximately 30 years. The inland region has an altitude of 1000 m above sea level and consequently low aggressiveness. The studied rusts were obtained from external and internal surfaces of the cannon barrels. This investigation, using three different techniques, was done to check if the relatively short time (ca. 30 years) in rural area was sufficient to change the characteristics of the thick rust formed during long time exposure (ca. 300 years) in marine atmosphere. The time-environment effects change the physical nature of rust, mainly observed by Moessbauer spectroscopy results

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

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

Science.gov (United States)

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

Nanostructure of protective rust layer on weathering steel examined using synchrotron radiation x-rays

International Nuclear Information System (INIS)

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

2004-01-01

The X-ray absorption fine structure (XAFS) spectrum of pure goethite around the Fe K absorption edge and that of the protective rust layer formed on weathering steel exposed for 17 years in an atmospheric environment around the Cr K edge, have been examined using synchrotron radiation X-rays. It was found that the rust layer on the weathering steel mainly consisted of Cr-goethite. By examining the fine structure at the Cr K edge and the Fe K edge, we concluded that Cr 3+ in the rust layer is coordinated with O 2- and is positioned in the double chains of vacant sites in the network of FeO 3 (OH) 3 octahedra in the goethite crystal. This Cr 3+ site indicates that the protective effect of the rust layer is due to the dense aggregation of fine crystals of Cr-goethite with cation selectivity. (author)

Influence of lactate ions on the formation of rust

International Nuclear Information System (INIS)

Sabot, R.; Jeannin, M.; Gadouleau, M.; Guo, Q.; Sicre, E.; Refait, Ph.

2007-01-01

The formation of rust can be simulated by oxidation of aqueous suspensions of Fe(OH) 2 obtained by mixing solutions of NaOH and a Fe(II) salt. The aim of this study was to investigate the influence of organic species associated with microbially influenced corrosion. The lactate anion, often used as a carbon and electrons source for the development of microorganisms, was chosen as an example. Then, in the first part of the study, Fe(OH) 2 was precipitated using iron(II) lactate and NaOH. Its oxidation process involved two stages, as usually observed. The first stage led to a Fe(II-III) intermediate compound, the lactate green rust, GR(C 3 H 5 O 3 - ). This compound has never been reported yet. Its existence demonstrates that the GR structure is able to incorporate a very wide range of anions, whatever the size and geometry. The second stage corresponded to the oxidation of GR(C 3 H 5 O 3 - ). It led to ferrihydrite, the most poorly ordered form of iron(III) oxides and oxyhydroxides. In the second part of the study, the formation of rust in seawater was simulated by oxidation of Fe(OH) 2 in an aqueous media containing both Cl - and SO 4 2- anions. The first stage led to the sulphate green rust, GR(SO 4 2- ), the second stage to lepidocrocite γ-FeOOH. Small amounts of iron(II) lactate were added to the reactants. Lactate ions did not modify the first stage but drastically perturbed the second stage, as ferrihydrite was obtained instead of γ-FeOOH

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

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...

Interaction in Short rotation coppice willow, Salix viminalis genotype mixtures

Energy Technology Data Exchange (ETDEWEB)

Begley, D. [Department of Biological Sciences, Queen' s University Belfast, Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom); McCracken, A.R. [Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom)]|[Northern Ireland Horticulture and Plant Breeding Station, Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, Loughgall, Co., Armagh BT61 8JB, Northern Ireland (United Kingdom); Dawson, W.M. [Northern Ireland Horticulture and Plant Breeding Station, Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, Loughgall, Co., Armagh BT61 8JB, Northern Ireland (United Kingdom); Watson, S. [Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom)

2009-02-15

Seven straight Salix viminalis genotypes with different levels of rust (Melampsora epitea) susceptibility were grown as mono-plots as well as being incorporated into a range of mixtures. Two 3-year harvests (2003 and 2006) were taken. Disease progress was followed on each of the individual genotypes throughout each growing season 2001-2006. In 2003 there were small but significant yield increases from the mixtures compared to the yield of individual components grown as mono-plots. These differences were not evident at the second harvest in 2006. No consistent effect of mixtures on reducing rust on the most susceptible genotype, Salix viminalis '77082' were observed. In some years, e.g. 2003, at certain times during the growing season, significant reductions were observed on Salix viminalis '77082' in certain 3-way mixtures compared to mono-plots. These, however, were not repeated consistently in subsequent years. It was concluded that the current commercial practice in many parts of Europe of planting mixtures as a disease control strategy will only be effective if there is sufficient genetic diversity between the Salix genotypes incorporated into the mixture. (author)

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.

Null fields realizations of W3 from W (sl(4), sl(3)) and W (sl(3/1), sl(3)) algebras

International Nuclear Information System (INIS)

Bellucci, S.; Krivonos, S.; Sorin, A.

1995-09-01

It is considered the nonlinear algebras W(sl(4), sl(3)) and W(sl(3/1), sl(3)) and it is found their realizations in terms of currents spanning conformal linearizing algebras. The specific structure of these algebras, allows to construct realizations modulo null fields of the W 3 algebra that lies in the cosets W(sl(4), sl(3))/u(1) and W(sl(3/1), sl(3))/u(1). Such realizations exist for the following values of the W 3 algebra central charge: cw=-30, -40/7, -98/5, -2. The first two values are listed for the first time, whereas for the remaining values the new realizations get in terms of an arbitrary stress tensor and u(1) x sl(2) affine currents

Marker-assisted pyramiding of Thinopyrumderived leaf rust ...

Indian Academy of Sciences (India)

2017-03-20

Mar 20, 2017 ... resistance genes Lr19 and Lr24 using marker assisted foreground .... is linked with stem rust resistance gene Sr24(McIntosh et al. 1976). .... Received 29 July 2016, in final revised form 3 March 2017; accepted 16 March 2017.

Rust types from JSON samples - Approximating type providers with procedural macros in Rust

OpenAIRE

Vesteraas, Erik Andreas

2017-01-01

When programmers access external data in a statically typed programming language, they are often faced with a dilemma between convenient and type-safe access to the data. In the programming language F#, a concept called type providers has been proposed as a solution to this problem by having compiler support for libraries with the capability to generate types at compile time. This thesis presents "json_typegen", a project which aims to show the feasibility of similar solutions in the Rust pro...

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

African Journals Online (AJOL)

SONY

2013-05-01

May 1, 2013 ... accelerating wheat production in the last forty years and ensured food security of the Nation. In the present investigation, Sr2 specific molecular markers were used to assess their efficacy for assessing the deployment of Sr2 gene in Indian wheat cultivars of highly productive north-west plains and stem rust ...

Fine Mapping of Ur-3, a Historically Important Rust Resistance Locus in Common Bean

Directory of Open Access Journals (Sweden)

Oscar P. Hurtado-Gonzales

2017-02-01

Full Text Available Bean rust, caused by Uromyces appendiculatus, is a devastating disease of common bean (Phaseolus vulgaris in the Americas and Africa. The historically important Ur-3 gene confers resistance to many races of the highly variable bean rust pathogen that overcome other rust resistance genes. Existing molecular markers tagging Ur-3 for use in marker-assisted selection produce false results. Here, we describe the fine mapping of the Ur-3 locus for the development of highly accurate markers linked to Ur-3. An F2 population from the cross Pinto 114 (susceptible × Aurora (resistant with Ur-3 was evaluated for its reaction to four different races of U. appendiculatus. A bulked segregant analysis using the SNP chip BARCBEAN6K_3 placed the approximate location of Ur-3 in the lower arm of chromosome Pv11. Specific SSR and SNP markers and haplotype analysis of 18 sequenced bean varieties positioned Ur-3 in a 46.5 kb genomic region from 46.96 to 47.01 Mb on Pv11. We discovered in this region the SS68 KASP marker that was tightly linked to Ur-3. Validation of SS68 on a panel of 130 diverse common bean cultivars containing all known rust resistance genes revealed that SS68 was highly accurate and produced no false results. The SS68 marker will be of great value in pyramiding Ur-3 with other rust resistance genes. It will also significantly reduce time and labor associated with the current phenotypic detection of Ur-3. This is the first utilization of fine mapping to discover markers linked to rust resistance in common bean.

Fine Mapping of Ur-3, a Historically Important Rust Resistance Locus in Common Bean.

Science.gov (United States)

Hurtado-Gonzales, Oscar P; Valentini, Giseli; Gilio, Thiago A S; Martins, Alexandre M; Song, Qijian; Pastor-Corrales, Marcial A

2017-02-09

Bean rust, caused by Uromyces appendiculatus , is a devastating disease of common bean ( Phaseolus vulgaris ) in the Americas and Africa. The historically important Ur-3 gene confers resistance to many races of the highly variable bean rust pathogen that overcome other rust resistance genes. Existing molecular markers tagging Ur-3 for use in marker-assisted selection produce false results. Here, we describe the fine mapping of the Ur-3 locus for the development of highly accurate markers linked to Ur-3 An F 2 population from the cross Pinto 114 (susceptible) × Aurora (resistant with Ur-3 ) was evaluated for its reaction to four different races of U. appendiculatus A bulked segregant analysis using the SNP chip BARCBEAN6K_3 placed the approximate location of Ur-3 in the lower arm of chromosome Pv11. Specific SSR and SNP markers and haplotype analysis of 18 sequenced bean varieties positioned Ur-3 in a 46.5 kb genomic region from 46.96 to 47.01 Mb on Pv11. We discovered in this region the SS68 KASP marker that was tightly linked to Ur-3 Validation of SS68 on a panel of 130 diverse common bean cultivars containing all known rust resistance genes revealed that SS68 was highly accurate and produced no false results. The SS68 marker will be of great value in pyramiding Ur-3 with other rust resistance genes. It will also significantly reduce time and labor associated with the current phenotypic detection of Ur-3 This is the first utilization of fine mapping to discover markers linked to rust resistance in common bean. Copyright © 2017 Hurtado-Gonzales et al.

Lr67/Yr46 confers adult plant resistance to stem rust and powdery mildew in wheat.

Science.gov (United States)

Herrera-Foessel, Sybil A; Singh, Ravi P; Lillemo, Morten; Huerta-Espino, Julio; Bhavani, Sridhar; Singh, Sukhwinder; Lan, Caixia; Calvo-Salazar, Violeta; Lagudah, Evans S

2014-04-01

We demonstrate that Lr67/Yr46 has pleiotropic effect on stem rust and powdery mildew resistance and is associated with leaf tip necrosis. Genes are designated as Sr55, Pm46 and Ltn3 , respectively. Wheat (Triticum aestivum) accession RL6077, known to carry the pleiotropic slow rusting leaf and yellow rust resistance genes Lr67/Yr46 in Thatcher background, displayed significantly lower stem rust (P. graminis tritici; Pgt) and powdery mildew (Blumeria graminis tritici; Bgt) severities in Kenya and in Norway, respectively, compared to its recurrent parent Thatcher. We investigated the resistance of RL6077 to stem rust and powdery mildew using Avocet × RL6077 F6 recombinant inbred lines (RILs) derived from two photoperiod-insensitive F3 families segregating for Lr67/Yr46. Greenhouse seedling tests were conducted with Mexican Pgt race RTR. Field evaluations were conducted under artificially initiated stem rust epidemics with Pgt races RTR and TTKST (Ug99 + Sr24) at Ciudad Obregon (Mexico) and Njoro (Kenya) during 2010-2011; and under natural powdery mildew epiphytotic in Norway at Ås and Hamar during 2011 and 2012. In Mexico, a mean reduction of 41 % on stem rust severity was obtained for RILs carrying Lr67/Yr46, compared to RILs that lacked the gene, whereas in Kenya the difference was smaller (16 %) but significant. In Norway, leaf tip necrosis was associated with Lr67/Yr46 and RILs carrying Lr67/Yr46 showed a 20 % reduction in mean powdery mildew severity at both sites across the 2 years of evaluation. Our study demonstrates that Lr67/Yr46 confers partial resistance to stem rust and powdery mildew and is associated with leaf tip necrosis. The corresponding pleiotropic, or tightly linked, genes, designated as Sr55, Pm46, and Ltn3, can be utilized to provide broad-spectrum durable disease resistance in wheat.

CHEMICAL INTERACTIONS OF ARSENATE, ARSENITE, PHOSPHATE, AND SILICATE WITH IRON (II, III) HYDROXYCARBONATE GREEN RUST

Science.gov (United States)

Granular zerovalent iron has been proposed to be used as a medium in permeable reactive barriers (PRBs) to remove arsenic from contaminated groundwater. Iron(II, III) hydroxycarbonate green rust (carbonate green rust, or CGR) is a major corrosion product of zerovalent iron under ...

Preparation and Eh-pH diagrams of Fe(II)-Fe(III) green rust compounds; hyperfine interaction characteristics and stoichiometry of hydroxy-chloride, -sulphate and -carbonate

International Nuclear Information System (INIS)

Genin, J.-M.R.; Refait, Ph.; Simon, L.; Drissi, S.H.

1998-01-01

Fe(II)-Fe(III) hydroxy-chloride, -sulphate and -carbonate were prepared by oxidation of a ferrous hydroxide precipitate in anion-containing aqueous solutions. The compounds are characterized by monitoring the redox potential E h and the pH of stochiometric suspension vs time with the appropriate concentration ratios. X-ray diffraction allows us to characterize the crystal structure by distinguishing 'green rust one' (GR1) from 'green rust two' (GR2). Since green rusts (GRs) are of a pyroaurite-sjoegrenite-like structure, i.e., consisting of intercalated foreign anions and water molecules in the interlayers between the brucite-like layers of Fe(OH) 2 , their chemical formulae can be determined from the Moessbauer spectra. Three quadrupole doublets are observed: D 1 and D 2 correspond to a ferrous state with isomershift IS of about 1.27 mm s -1 and quadrupole splittings QS of about 2.85 and 2.60 mm s -1 , respectively, whereas D 3 corresponds to a ferric state with IS and QS of about 0.4 mm s -1 . The hyperfine parameters of these doublets are similar from one green rust to another but their intensity ratios vary considerably. Finally, E h and pH equilibrium diagrams of the Fe species in the presence of chloride, sulphate and carbonate anions contained within the water solution are drawn and the thermodynamic conditions of existence and degrees of oxidation of green rusts are discussed

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)

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.

Prediction of yield losses in wheat (triticum aestivum l.) caused by yellow rust in relation to epidemiological factors in Faisalabad

International Nuclear Information System (INIS)

Ahmad, S.; Afzal, M.; Noorka, I.R.; Iqbal, Z.; Akhtar, N.; Iiftikhar, Y.; Kamran, M.

2010-01-01

Thirty six genotypes were screened against yellow rust to check their level of susceptibility or resistance. Among 36 genotypes screened against yellow rust, 18 were susceptible, 6 were moderately susceptible to susceptible, 7 were moderately resistant to moderately susceptible and 5 genotypes remained resistant. Yield losses were predicted in wheat on the basis of varying level of yellow rust severities. It was observed that susceptible genotypes showed higher yield losses as compared to resistant genotypes. Maximum severity of 90% of yellow rust resulted in 54% to 55% calculated and predicted losses, respectively. While 40, 50, 60 and 70% disease severity of yellow rust caused 35-34%, 38-37%, 42-40% and 46-47% calculated and predicted losses, respectively. However, the decline in losses was observed as the genotypes changed their reaction from susceptible to moderate susceptible. Similarly, losses were diminished as the varieties/lines showed moderate resistant reaction from moderate susceptible. Minimum temperature and relative humidity remained positively correlated while the maximum temperature showed negative correlation with stripe rust severity. With the increase of minimum temperature and relative humidity a rise up in stripe rust infection was seen while as the maximum temperature increased stripe rust infection decreased on different genotypes. It may be concluded from the study that environmental factors played major role in the spread of the disease which result in yield losses. (author)

Influence of Rust Permeability on Corrosion of E690 Steel in Industrial and Non-industrial Marine Splash Zones

Science.gov (United States)

Chen, Mindong; Pang, Kun; Liu, Zhiyong; Wu, Junsheng; Li, Xiaogang

2018-05-01

The corrosion behaviour of E690 steel in industrial and non-industrial marine splash environments was studied by environmental testing, morphology analysis, electrochemical measurements, and scanning Kelvin probe microscopy. Chloride and sulphide anions were found to diffuse across the rust layer following the evaporation of seawater splashed on the steel's surface. The cation-selective permeability of the rust layer resulted in an anion concentration gradient across the rust layer, which was more significant in the presence of sulphur dioxide. In addition, sulphur dioxide enhanced the formation of α-FeOOH, which led to the formation of distinct anode and cathode areas at the rust/steel interface.

Wheat Ammonium Transporter (AMT) Gene Family: Diversity and Possible Role in Host-Pathogen Interaction with Stem Rust.

Science.gov (United States)

Li, Tianya; Liao, Kai; Xu, Xiaofeng; Gao, Yue; Wang, Ziyuan; Zhu, Xiaofeng; Jia, Baolei; Xuan, Yuanhu

2017-01-01

Ammonium transporter (AMT) proteins have been reported in many plants, but no comprehensive analysis was performed in wheat. In this study, we identified 23 AMT members (hereafter TaAMTs) using a protein homology search in wheat genome. Tissue-specific expression analysis showed that TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a were relatively more highly expressed in comparison with other TaAMTs . TaAMT1;1a, TaAMT1;1b, and TaAMT1;3a-GFP were localized in the plasma membrane in tobacco leaves, and TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a successfully complemented a yeast 31019b strain in which ammonium uptake was deficient. In addition, the expression of TaAMT1;1b in an Arabidopsis AMT quadruple mutant ( qko ) successfully restored [Formula: see text] uptake ability. Resupply of [Formula: see text] rapidly increased cellular [Formula: see text] contents and suppressed expression of TaAMT1;3a , but not of TaAMT;1;1a and TaAMT1;1b expressions. Expression of TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a was not changed in leaves after [Formula: see text] resupply. In contrast, nitrogen (N) deprivation induced TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a gene expressions in the roots and leaves. Expression analysis in the leaves of the stem rust-susceptible wheat line "Little Club" and the rust-tolerant strain "Mini 2761" revealed that TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a were specifically induced in the former but not in the latter. Rust-susceptible wheat plants grown under N-free conditions exhibited a lower disease index than plants grown with [Formula: see text] as the sole N source in the medium after infection with Puccinia graminis f. sp. tritici , suggesting that [Formula: see text] and its transport may facilitate the infection of wheat stem rust disease. Our findings may be important for understanding the potential function TaAMTs in wheat plants.

SEASONALITY OF THE LEAF MINER, LEVEL OF PREDATION AND TEMPORAL OCCURRENCE OF RUST CORRELATED TO ABIOTIC FACTORS

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B. M. R. Melo

2018-04-01

Full Text Available The coffee leaf miner and a rust are considered as major diseases that are able to reduce productivity in coffee plantations. These agents are influenced by abiotic factors, and their occurrence may suffer oscillation over the years. The objective of this study was to evaluate the seasonal fluctuation of the coffee leaf miner, incidence of coffee prediction and rust, correlated with abiotic factors. The study was performed IFSULDEMINAS-Campus Inconfidentes, in a coffee crop of the cultivar Rubi. A sample for a rust and a coffee leaf miner, in addition to the middle and upper third of the plants, totaling 42 plants in the study area. At the same sampling point, perform soil analysis to correlate nutrients as studied variables. The Pearson correlation of the biotic variables was performed with a precipitation and fertility, a rate of 1 and 5% probability. It was verified that the rust cycle alternated its incidence for the same period in different years and the miner showed behavior coincident to the driest periods of the year. Data not available on precipitation data and number of mines. These diseases had no significant correlation with the fertility parameter. The coffee leaf miner yielded higher rates of occurrence in June and December of 2014. It was concluded that the percentage of coffee leaf miner was higher in the months with lower rainfall indices or no longer summer period; What is it you want to know about the one-time development that may have been influenced by the nearby woods under study and the rust alternated the peaks of occurrence for the two autumners, correlating with a precipitation.

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 on vir...... that wheat rust fungi can adapt to warmer temperatures and cause severe disease in previously unfavorable environments......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...... regimes for latent period, lesion length, lesion width, lesion area, and spore production on adult plants of a susceptible wheat cultivar with no known genes for resistance to stripe rust. "New" isolates (since 2000) were significantly more aggressive than "old" isolates (before 2000) for all variables...

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

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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.

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)

Multi-location wheat stripe rust QTL analysis: genetic background and epistatic interactions.

Science.gov (United States)

Vazquez, M Dolores; Zemetra, Robert; Peterson, C James; Chen, Xianming M; Heesacker, Adam; Mundt, Christopher C

2015-07-01

Epistasis and genetic background were important influences on expression of stripe rust resistance in two wheat RIL populations, one with resistance conditioned by two major genes and the other conditioned by several minor QTL. Stripe rust is a foliar disease of wheat (Triticum aestivum L.) caused by the air-borne fungus Puccinia striiformis f. sp. tritici and is present in most regions around the world where commercial wheat is grown. Breeding for durable resistance to stripe rust continues to be a priority, but also is a challenge due to the complexity of interactions among resistance genes and to the wide diversity and continuous evolution of the pathogen races. The goal of this study was to detect chromosomal regions for resistance to stripe rust in two winter wheat populations, 'Tubbs'/'NSA-98-0995' (T/N) and 'Einstein'/'Tubbs' (E/T), evaluated across seven environments and mapped with diversity array technology and simple sequence repeat markers covering polymorphic regions of ≈1480 and 1117 cM, respectively. Analysis of variance for phenotypic data revealed significant (P located in chromosomes 2AS and 6AL, with epistatic interaction between them, were responsible for the main phenotypic response. For the T/N population, eight QTL were identified, with those in chromosomes 2AL and 2BL accounting for the largest percentage of the phenotypic variance.

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

Indian Academy of Sciences (India)

Mona Singh

2017-12-08

Dec 8, 2017 ... Abstract. This study was undertaken to pyramid two effective leaf rust resistance genes (Lr19 and Lr24) derived from ... genes such as Lr9, Lr19, Lr26 and Lr28 became ineffective ..... Disease management recommendations.

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

Sustracted library obtained from mutant sugarcane variety B 4362 resistant to rust

OpenAIRE

María I. Oloriz; Luis Rojas; Víctor Gil; Elio Jiménez

2002-01-01

The hypersensitive response is one of the most powerful mechanisms for which the plants resist pathogen attack. Mutations carried out previously on the variety B4362, of sugarcane, originated five mutants that express this mechanism towards the attack of rust (Puccinia melanocephala Syd.). By means of a subtractive hybridization among the cDNA obtained starting from the resistant clone inoculated with rust and a pool of cDNA of the susceptible variety (B4362) inoculated and of the resistant c...

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.

Targeted introgression of stem rust Ug99 resistance from wheatgrasses into pasta and bread wheat

Science.gov (United States)

In the past 50 years, a number of stem rust resistance (Sr) genes have been transferred from several wheat-related grasses into durum (i.e. pasta) and bread wheat through chromosome translocations and additions. To utilize these genes for controlling the Ug99 races of the stem rust pathogen, we ini...

FLUXAPYROXAD IN THE ASIAN SOYBEAN RUST CONTROL IN THE CERRADO BIOME

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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.

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.

Corrosion-resistant amorphous alloy ribbons for electromagnetic filtration of iron rusts from water

International Nuclear Information System (INIS)

Kawashima, Asahi; Asami, Katsuhiko; Sato, Takeaki; Hashimoto, Koji

1985-01-01

An attempt was made to use corrosion-resistant amorphous Fe-9Cr-13P-7C alloy ribbons as an electromagnetic filter material for trapping various iron rusts suspended in water at 40 0 C. The ferrimagnetic Fe 3 O 4 rust was trapped with the 100 % efficiency and paramagnetic rusts such as α-Fe 2 O 3 , α-FeOOH and amorphous ferric oxyhydroxide were trapped with certain efficiencies at the magnetic field strength of 0.5-10 kOe. The regeneration of the filter by back-washing was easy. The trapping capacity of electromagnetic filter was proportional to the edge length of the filter material where the high magnetic field strength existed. Therefore, melt-spun thin and narrow amorphous alloy ribbons having the high corrosion resistance have the potential utility as electromagnetic filter material. (author)

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

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

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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.

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.

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.

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.

26 CFR 1.414(w)-1 - Permissible withdrawals from eligible automatic contribution arrangements.

Science.gov (United States)

2010-04-01

... contribution arrangements. 1.414(w)-1 Section 1.414(w)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Plans, Etc. § 1.414(w)-1 Permissible withdrawals from eligible automatic contribution arrangements. (a) Overview. Section 414(w) provides rules under which certain employees are permitted to elect to make a...

A 1.1nW Energy Harvesting System with 544pW Quiescent Power for Next Generation Implants.

Science.gov (United States)

Bandyopadhyay, Saurav; Mercier, Patrick P; Lysaght, Andrew C; Stankovic, Konstantina M; Chandrakasan, Anantha P

2014-12-01

This paper presents a nW power management unit (PMU) for an autonomous wireless sensor that sustains itself by harvesting energy from the endocochlear potential (EP), the 70-100 mV electrochemical bio-potential inside the mammalian ear. Due to the anatomical constraints inside the inner ear, the total extractable power from the EP is limited to 1.1-6.25 nW. A nW boost converter is used to increase the input voltage (30-55 mV) to a higher voltage (0.8 to 1.1 V) usable by CMOS circuits in the sensor. A pW Charge Pump circuit is used to minimize the leakage in the boost converter. Further, ultra-low-power control circuits consisting of digital implementations of input impedance adjustment circuits and Zero Current Switching circuits along with Timer and Reference circuits keep the quiescent power of the PMU down to 544 pW. The designed boost converter achieves a peak power conversion efficiency of 56%. The PMU can sustain itself and a duty-cyled ultra-low power load while extracting power from the EP of a live guinea pig. The PMU circuits have been implemented on a 0.18µm CMOS process.

Biology and pathology of Ribes and their implications for management of white pine blister rust

Science.gov (United States)

P. J. Zambino

2010-01-01

Ribes (currants and gooseberries) are telial hosts for the introduced and invasive white pine blister rust fungus, Cronartium ribicola. Knowledge of wild and introduced Ribes helps us understand the epidemiology of blister rust on its aecial hosts, white pines, and develop disease control and management strategies. Ribes differ by species in their contribution to...

Kinetics of structural rust transformation in environments containing chloride and SO2

Directory of Open Access Journals (Sweden)

Valencia, A.

2003-12-01

Full Text Available The behavior of the rusts produced on low carbon steel exposed in industrial atmospheres, at different distances from the sea, was studied by simulating the wetting-drying cycle in a CEBELCOR type apparatus. Coupons electrode potential was monitored and rust layer was analyzed by gravimetric techniques, optical microscopy and Mössbauer spectroscopy. A particular chloride/sulfur ratio in the atmosphere was found, for which there is a particular behavior in rust formation. For this ratio, corrosion rates were much less than expected. It is postulated a kinetic mechanism for rust layer formation as the origin of this special behavior. An electrode potential similar to that in a weathering steel was observed, this is reflected in the low corrosion rate obtained. The proposed kinetic mechanism for rust formation under these exposure conditions enables new research lines on layer formation and the development of protective rust for industrial marine atmospheres.Se estudió el comportamiento de las herrumbres de un acero de bajo carbono expuesto en la simulación de atmósferas industriales con diferentes distancias al mar, con del ciclo de humectación y secado en el ensayo CEBELCOR y en soluciones representativas de las atmósferas en cuestión. Se hizo seguimiento del potencial de electrodo de los cuerpos de prueba y se analizó la capa de productos de corrosión por técnicas gravimétricas, microscopía óptica y espectroscopia Mössbauer. Se determinó un valor de cloruros y sulfatos en la atmósfera que genera un comportamiento particular en la formación de la herrumbre, presentando velocidades de corrosión menores a las esperadas para el tenor de agentes agresivos, y se postuló un mecanismo cinético en la formación de la película como causante del fenómeno particular. Se observó un comportamiento del potencial próximo al de un acero autoprotector, que se refleja en una menor velocidad de corrosión. La propuesta del mecanismo cin

Screening for sugarcane brown rust in first clonal stage of the Canal Point sugarcane breeding program

Science.gov (United States)

Sugarcane (Saccharum spp.) brown rust (caused by Puccinia melanocephala H. & P. Sydow) was first reported in the United States in 1978 and is still one of great challenges for sugarcane production. A better understanding of sugarcane genotypic variation in response to brown rust will help optimize b...

Measurement of the w boson mass and $w^{+} w^{-}$ production and decay properties in $e^{+}e^{-}$ collisions at s**(1/2) = 172-GeV

CERN Document Server

Ackerstaff, K.; Allison, John; Altekamp, N.; Anderson, K.J.; Anderson, S.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Bartoldus, R.; Batley, J.R.; Baumann, S.; Bechtluft, J.; Beeston, C.; Behnke, T.; Bell, A.N.; Bell, Kenneth Watson; Bella, G.; Bentvelsen, S.; Bethke, S.; Biebel, O.; Biguzzi, A.; Bird, S.D.; Blobel, V.; Bloodworth, I.J.; Bloomer, J.E.; Bobinski, M.; Bock, P.; Bonacorsi, D.; Boutemeur, M.; Bouwens, B.T.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Burgard, C.; Burgin, R.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Clarke, P.E.L.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Cuffiani, M.; Dado, S.; Dallapiccola, C.; Dallavalle, G.Marco; Davies, R.; De Jong, S.; del Pozo, L.A.; Desch, K.; Dienes, B.; Dixit, M.S.; do Couto e Silva, E.; Doucet, M.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Eatough, D.; Edwards, J.E.G.; Estabrooks, P.G.; Evans, H.G.; Evans, M.; Fabbri, F.; Fanti, M.; Faust, A.A.; Fiedler, F.; Fierro, M.; Fischer, H.M.; Fleck, I.; Folman, R.; Fong, D.G.; Foucher, M.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gascon, J.; Gascon-Shotkin, S.M.; Geddes, N.I.; Geich-Gimbel, C.; Geralis, T.; Giacomelli, G.; Giacomelli, P.; Giacomelli, R.; Gibson, V.; Gibson, W.R.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Goodrick, M.J.; Gorn, W.; Grandi, C.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Hargrove, C.K.; Hart, P.A.; Hartmann, C.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herndon, M.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hillier, S.J.; Hobson, P.R.; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Hutchcroft, D.E.; Igo-Kemenes, P.; Imrie, D.C.; Ingram, M.R.; Ishii, K.; Jawahery, A.; Jeffreys, P.W.; Jeremie, H.; Jimack, M.; Joly, A.; Jones, C.R.; Jones, G.; Jones, M.; Jost, U.; Jovanovic, P.; Junk, T.R.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kirk, J.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Koetke, D.S.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kress, T.; Krieger, P.; von Krogh, J.; Kyberd, P.; Lafferty, G.D.; Lahmann, R.; Lai, W.P.; Lanske, D.; Lauber, J.; Lautenschlager, S.R.; Layter, J.G.; Lazic, D.; Lee, A.M.; Lefebvre, E.; Lellouch, D.; Letts, J.; Levinson, L.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Ludwig, J.; Macchiolo, A.; Macpherson, A.; Mannelli, M.; Marcellini, S.; Markus, C.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menke, S.; Merritt, F.S.; Mes, H.; Meyer, J.; Michelini, A.; Mikenberg, G.; Miller, D.J.; Mincer, A.; Mir, R.; Mohr, W.; Montanari, A.; Mori, T.; Morii, M.; Muller, U.; Mihara, S.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nellen, B.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Oh, A.; Oldershaw, N.J.; Oreglia, M.J.; Orito, S.; Palinkas, J.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Pearce, M.J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poffenberger, P.; Poli, B.; Posthaus, A.; Rees, D.L.; Rigby, D.; Robertson, S.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rooke, A.; Ros, E.; Rossi, A.M.; Routenburg, P.; Rozen, Y.; Runge, K.; Runolfsson, O.; Ruppel, U.; Rust, D.R.; Rylko, R.; Sachs, K.; Saeki, T.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharf, F.; Scharff-Hansen, P.; Schenk, P.; Schieck, J.; Schleper, P.; Schmitt, B.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schultz-Coulon, H.C.; Schumacher, M.; Schwick, C.; Scott, W.G.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Sittler, A.; Skillman, A.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Springer, Robert Wayne; Sproston, M.; Stephens, K.; Steuerer, J.; Stockhausen, B.; Stoll, K.; Strom, David M.; Szymanski, P.; Tafirout, R.; Talbot, S.D.; Tanaka, S.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomson, M.A.; von Torne, E.; Towers, S.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turcot, A.S.; Turner-Watson, M.F.; Utzat, P.; Van Kooten, Rick J.; Verzocchi, M.; Vikas, P.; Vokurka, E.H.; Voss, H.; Wackerle, F.; Wagner, A.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wermes, N.; White, J.S.; Wilkens, B.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Yekutieli, G.; Zacek, V.; Zer-Zion, D.

1998-01-01

This paper describes the measurement of the W boson mass, M_W, and decay width, Gamma_W, from the direct reconstruction of the invariant mass of its decay products in W pair events collected at a mean centre-of-mass energy of sqrt{s} = 172.12 GeV with the OPAL detector at LEP. Measurements of the W pair production cross-section, the W decay branching fractions and properties of the W decay final states are also described. A total of 120 candidate W^+W^- events has been selected for an integrated luminosity of 10.36 pb^-1. The W^+W^- production cross-section is measured to be sigma_WW = 12.3 +/- 1.3(stat.) +/- 0.3(syst.) pb, consistent with the Standard Model expectation. The W^+W^- -> qq(bar) l nu and W^+W^- -> qq(bar)qq(bar) final states are used to obtain a direct measurement of Gamma_W = 1.30^{+0.62}_{-0.55}(stat.) +/- 0.18(syst.) GeV. Assuming the Standard Model relation between M_W and Gamma_W, the W boson mass is measured to be M_W = 80.32 +/- 0.30(stat.) +/- 0.09(syst.) GeV. The event properties of the...

Evaluation of Fracture and Osteotomy Union in the Setting of Osteogenesis Imperfecta: Reliability of the Modified Radiographic Union Score for Tibial Fractures (RUST).

Science.gov (United States)

Franzone, Jeanne M; Finkelstein, Mark S; Rogers, Kenneth J; Kruse, Richard W

2017-09-08

Evaluation of the union of osteotomies and fractures in patients with osteogenesis imperfecta (OI) is a critical component of patient care. Studies of the OI patient population have so far used varied criteria to evaluate bony union. The radiographic union score for tibial fractures (RUST), which was subsequently revised to the modified RUST, is an objective standardized method of evaluating fracture healing. We sought to evaluate the reliability of the modified RUST in the setting of the tibias of patients with OI. Tibial radiographs of 30 patients with OI fractures, or osteotomies were scored by 3 observers on 2 separate occasions. Each of the 4 cortices was given a score (1=no callus, 2=callus present, 3=bridging callus, and 4=remodeled, fracture not visible) and the modified RUST is the sum of these scores (range, 4 to 16). The interobserver and intraobserver reliabilities were evaluated using intraclass coefficients (ICC) with 95% confidence intervals. The ICC representing the interobserver reliability for the first iteration of scores was 0.926 (0.864 to 0.962) and for the second series was 0.915 (0.845 to 0.957). The ICCs representing the intraobserver reliability for each of the 3 reviewers for the measurements in series 1 and 2 were 0.860 (0.707 to 0.934), 0.994 (0.986 to 0.997), and 0.974 (0.946 to 0.988). The modified RUST has excellent interobserver and intraobserver reliability in the setting of OI despite challenges related to the poor quality of the bone and its dysplastic nature. The application and routine use of the modified RUST in the OI population will help standardize our evaluation of osteotomy and fracture healing. Level III-retrospective study of nonconsecutive patients.

Blister rust in North America: What we have not learned in the past 100 years

Science.gov (United States)

Eugene P. Van Arsdel; Brian W. Geils

2011-01-01

Introduction of Cronartium ribicola (white pine blister rust) greatly motivated development of tree disease control and research in America. Although foresters and pathologists have learned much in the past 100 years, more remains to learn. The most important lesson is that fear of blister rust has reduced pine regeneration more than the disease itself. Based on six...

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

NARCIS (Netherlands)

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

2001-01-01

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

Comparative transcriptome analysis and identification of candidate effectors in two related rust species (Gymnosporangium yamadae and Gymnosporangium asiaticum).

Science.gov (United States)

Tao, Si-Qi; Cao, Bin; Tian, Cheng-Ming; Liang, Ying-Mei

2017-08-23

Rust fungi constitute the largest group of plant fungal pathogens. However, a paucity of data, including genomic sequences, transcriptome sequences, and associated molecular markers, hinders the development of inhibitory compounds and prevents their analysis from an evolutionary perspective. Gymnosporangium yamadae and G. asiaticum are two closely related rust fungal species, which are ecologically and economically important pathogens that cause apple rust and pear rust, respectively, proved to be devastating to orchards. In this study, we investigated the transcriptomes of these two Gymnosporangium species during the telial stage of their lifecycles. The aim of this study was to understand the evolutionary patterns of these two related fungi and to identify genes that developed by selection. The transcriptomes of G. yamadae and G. asiaticum were generated from a mixture of RNA from three biological replicates of each species. We obtained 49,318 and 54,742 transcripts, with N50 values of 1957 and 1664, for G. yamadae and G. asiaticum, respectively. We also identified a repertoire of candidate effectors and other gene families associated with pathogenicity. A total of 4947 pairs of putative orthologues between the two species were identified. Estimation of the non-synonymous/synonymous substitution rate ratios for these orthologues identified 116 pairs with Ka/Ks values greater than1 that are under positive selection and 170 pairs with Ka/Ks values of 1 that are under neutral selection, whereas the remaining 4661 genes are subjected to purifying selection. We estimate that the divergence time between the two species is approximately 5.2 Mya. This study constitutes a de novo assembly and comparative analysis between the transcriptomes of the two rust species G. yamadae and G. asiaticum. The results identified several orthologous genes, and many expressed genes were identified by annotation. Our analysis of Ka/Ks ratios identified orthologous genes subjected to

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

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...

Moessbauer spectroscopic study of rust formed on a weathering steel and a mild steel exposed for a long term in an industrial environment

International Nuclear Information System (INIS)

Kamimura, Takayuki; Nasu, Saburo; Tazaki, Takashi; Kuzushita, Kaori; Morimoto, Shotaro

2002-01-01

The rusts formed on mild steel (15-year exposure) and weathering steel (32-year exposure) exposed to an industrial environment have been characterized by means of X-ray diffraction technique and 57 Fe Moessbauer spectroscopy. By using an X-ray diffraction method, it is suggested that the rusts formed on both steels consist of the crystalline α-FeOOH, γ-FeOOH and an X-ray amorphous phase, which gives no peak to X-ray diffraction pattern. The amount of the X-ray amorphous phase exceeds 50% of the total amount of the rust. The 57 Fe Moessbauer spectra observed at 10K indicate that the rust contains only α-FeOOH, γ-FeOOH and Fe 3-δ O 4 (γ-Fe 2 O 3 ) for mild steel, and only α-FeOOH and γ-FeOOH for weathering steel. The X-ray amorphous substance in the rust payer formed on mild steel possesses the structures of mainly α-FeOOH showing superparamagnetism owing to its small particle size, and Fe 3-δ O 4 (γ-Fe 2 O 3 ). They are contained both in the inner rust layer and in the outer rust layer. The X-ray amorphous phase in the rust layer formed on weathering steel is mainly α-FeOOH. (author)

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.

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.

Protective, curative and eradicative activities of fungicides against grapevine rust

Directory of Open Access Journals (Sweden)

Francislene Angelotti

2014-01-01

Full Text Available The protective, eradicative and curative activities of the fungicides azoxystrobin, tebuconazole, pyraclostrobin+metiram, and ciproconazole against grapevine rust, were determined in greenhouse. To evaluate the protective activity, leaves of potted ´Niagara´ (Vitis labrusca vines were artificially inoculated with an urediniospore suspension of Phakopsora euvitis four, eight or forteen days after fungicidal spray; and to evaluate the curative and eradicative activities, leaves were sprayed with fungicides two, four or eight days after inoculation. Disease severity was assessed 14 days after each inoculation. All tested fungicides present excellent preventive activity against grapevine rust; however, tebuconazole and ciproconazole provide better curative activity than azoxystrobin and pyraclostrobin+metiram. It was observed also that all tested fungicides significantly reduced the germination of urediniospore produced on sprayed leaves.

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)

Extraction of High Molecular Weight DNA from Fungal Rust Spores for Long Read Sequencing.

Science.gov (United States)

Schwessinger, Benjamin; Rathjen, John P

2017-01-01

Wheat rust fungi are complex organisms with a complete life cycle that involves two different host plants and five different spore types. During the asexual infection cycle on wheat, rusts produce massive amounts of dikaryotic urediniospores. These spores are dikaryotic (two nuclei) with each nucleus containing one haploid genome. This dikaryotic state is likely to contribute to their evolutionary success, making them some of the major wheat pathogens globally. Despite this, most published wheat rust genomes are highly fragmented and contain very little haplotype-specific sequence information. Current long-read sequencing technologies hold great promise to provide more contiguous and haplotype-phased genome assemblies. Long reads are able to span repetitive regions and phase structural differences between the haplomes. This increased genome resolution enables the identification of complex loci and the study of genome evolution beyond simple nucleotide polymorphisms. Long-read technologies require pure high molecular weight DNA as an input for sequencing. Here, we describe a DNA extraction protocol for rust spores that yields pure double-stranded DNA molecules with molecular weight of >50 kilo-base pairs (kbp). The isolated DNA is of sufficient purity for PacBio long-read sequencing, but may require additional purification for other sequencing technologies such as Nanopore and 10× Genomics.

Morphology of germlings of urediniospores and its value for the identification and classification of grass rust fungi

NARCIS (Netherlands)

Swertz, C.A.

1994-01-01

The identification and classification of grass rust fungi is often difficult since most traditionally used morphological characters are quantitative and subjective. Besides, when using the host range as a taxonomic criterion, it is important to realize that a rust fungus may have jumped to

Transfer of genes for stem rust resistance from Agropyron elongatum and imperial rye to durum wheat

International Nuclear Information System (INIS)

Prabhakara Rao, M.V.

1977-01-01

The Agropyron elongatum gene for stem rust resistance on chromosome 6A of Knott's Thatcher translocation line was transferred to a susceptible local durum wheat variety, Jaya, through a series of back-crosses. Plants heterozygous for the Agropyron translocation always show at least one open bivalent. Homozygotes have not been obtained, probably because of the absence of male transmission in durum background. Monotelosomic addition of the short arm of Imperial rye chromosome 3R (formerly ''G'' of Sears), which carries a gene(s) for resistance to wheat stem rust, was obtained in the local durum variety. Rust-resistant plants from parents having the added rye telocentric were irradiated with gamma rays just before meiosis, and the pollen obtained from the irradiated spikes was used to pollinate euploid plants. In addition, seeds harvested from 2n+1 resistant plants were irradiated with thermal neutrons and the resistant M 1 plants were selfed to raise M 2 families. Two durum-rye translocation lines were obtained following irradiation. DRT-1 was transmitted normally through the female gametes but showed no male transmission. As a result of this, homozygotes have not been obtained. Gametic transmission rates of DRT-2 are being tested. Alien translocations, which show normal gametic and zygotic transmissions in the hexaploid wheat, may behave differently in a tetraploid background. The results indicate that alien genetic transfers may be more difficult to obtain in durum wheat, probably owing to the reduced buffering effect of the tetraploid genome. (author)

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)

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

Science.gov (United States)

2011-03-15

... Requirements for Addition of Rust-Resistant Varieties AGENCY: Animal and Plant Health Inspection Service, USDA... Rust-Resistant Varieties. OMB Number: 0579-0186. Type of Request: Extension of approval of an... products to prevent the introduction of plant pests into the United States or their dissemination within...

Dissection of the multigenic wheat stem rust resistance present in the Montenegrin spring wheat accession PI 362698

Science.gov (United States)

Research to identify and characterize stem rust resistance genes in common wheat, Triticum aestivum, has been stimulated by the emergence of Ug99-lineage races of the wheat stem rust pathogen, Puccinia graminis f. sp. tritici (Pgt), in Eastern Africa. The Montenegrin spring wheat landrace PI 362698 ...

Characterisation of rust surfaces formed on mild steel exposed to marine atmospheres using XRD and SEM/Micro-Raman techniques

International Nuclear Information System (INIS)

Fuente, D. de la; Alcántara, J.; Chico, B.; Díaz, I.; Jiménez, J.A.; Morcillo, M.

2016-01-01

Highlights: • SEM/Micro-Raman is very useful for characterizing rust phases morphologies. • SEM/Micro-Raman enables unequivocal rust phases identification. • γ-FeOOH basically presents two types of morphologies: globular and laminar. • Fe 3 O 4 presents two morphologies: flat patches and black doughnut-type formations. • β-FeOOH presents highly porous morphologies comprised by fine prismatic crystals. - Abstract: The exposure of mild steel to marine atmospheres gives rise to the formation of various corrosion products, mainly lepidocrocite, goethite, magnetite and akaganeite. In this study, Grazing Incidence X-Ray Diffraction, Micro-X-Ray Diffraction and Scanning Electron Microscopy/Micro-Raman are used to characterise rust layer surfaces and to identify the principal component rust phases and their morphology. The main conclusion reached is that lepidocrocite is preferentially located on the outermost surface while magnetite and akaganeite form mostly close to base steel. The Scanning Electron Microscopy/Micro-Raman technique has been very useful for characterising (identifying) the wide variety of morphologies presented by the rust phases.

Prescreening slash pine and Cronartium pedigrees for evaluation of complementary gene action in fusiform rust disease.

Science.gov (United States)

H.E. Stelzer; Robert L. Doudrick; Thomas L. Kubisiak; C. Dana Nelson

1999-01-01

Single-urediniospore cultures of the fusiform rust fungus were used to inoculate seedlings from 10 full-sib families of a five-parent slash pine diallel at two different times in 1994. The presence or absence of fusiform rust galls was recorded for each inoculated seedling at 9 months postinoculation, and percent infection levels for each family-inoculum-time...

Screening of fungicides for the management of wattle rust ...

African Journals Online (AJOL)

% of the revenue from the species obtained from the timber and 15% from the bark. From 2012/13 a wattle rust disease has spread throughout the black wattle plantation area in KwaZulu-Natal and from 2015 it was recorded in southern ...

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...

Cytogenetic analysis and mapping of leaf rust resistance in Aegilops speltoides Tausch derived bread wheat line Selection2427 carrying putative gametocidal gene(s).

Science.gov (United States)

Niranjana, M; Vinod; Sharma, J B; Mallick, Niharika; Tomar, S M S; Jha, S K

2017-12-01

Leaf rust (Puccinia triticina) is a major biotic stress affecting wheat yields worldwide. Host-plant resistance is the best method for controlling leaf rust. Aegilops speltoides is a good source of resistance against wheat rusts. To date, five Lr genes, Lr28, Lr35, Lr36, Lr47, and Lr51, have been transferred from Ae. speltoides to bread wheat. In Selection2427, a bread wheat introgresed line with Ae. speltoides as the donor parent, a dominant gene for leaf rust resistance was mapped to the long arm of chromosome 3B (LrS2427). None of the Lr genes introgressed from Ae. speltoides have been mapped to chromosome 3B. Since none of the designated seedling leaf rust resistance genes have been located on chromosome 3B, LrS2427 seems to be a novel gene. Selection2427 showed a unique property typical of gametocidal genes, that when crossed to other bread wheat cultivars, the F 1 showed partial pollen sterility and poor seed setting, whilst Selection2427 showed reasonable male and female fertility. Accidental co-transfer of gametocidal genes with LrS2427 may have occurred in Selection2427. Though LrS2427 did not show any segregation distortion and assorted independently of putative gametocidal gene(s), its utilization will be difficult due to the selfish behavior of gametocidal genes.

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 ...

Incorporation of water-in-oil-in-water (W1/O/W2) double emulsion in a set-type yogurt model.

Science.gov (United States)

Lalou, Sofia; Kadri, Hani El; Gkatzionis, Konstantinos

2017-10-01

The effect of W 1 /O/W 2 emulsion incorporation in set-type yogurt on the acidification process, physicochemical properties, bacterial growth kinetics and structural characteristics was investigated. The W 1 /O/W 2 emulsion was formed by using a two-step homogenisation process and milk as the W 1 and W 2 phases, and stability was monitored with optical microscopy and cryo-SEM. Adding the W 1 /O/W 2 emulsions reduced the acidification rate, viscosity and water retention capacity. Texture (adhesiveness, cohesiveness, hardness, and gumminess) differed in yogurts containing W 1 /O/W 2 emulsion compared to controls during the acidification process, however, trends became stable during storage. The growth of S. thermophilus during the acidification process of yogurt was reduced in the presence of W 1 /O/W 2 emulsion while L. bulgaricus trended higher during storage. This study shows that yogurts containing W 1 /O/W 2 emulsion are feasible subject to processing modification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetics and mapping of the R₁₁ gene conferring resistance to recently emerged rust races, tightly linked to male fertility restoration, in sunflower (Helianthus annuus L.).

Science.gov (United States)

Qi, L L; Seiler, G J; Vick, B A; Gulya, T J

2012-09-01

Sunflower oil is one of the major sources of edible oil. As the second largest hybrid crop in the world, hybrid sunflowers are developed by using the PET1 cytoplasmic male sterility system that contributes to a 20 % yield advantage over the open-pollinated varieties. However, sunflower production in North America has recently been threatened by the evolution of new virulent pathotypes of sunflower rust caused by the fungus Puccinia helianthi Schwein. Rf ANN-1742, an 'HA 89' backcross restorer line derived from wild annual sunflower (Helianthus annuus L.), was identified as resistant to the newly emerged rust races. The aim of this study was to elucidate the inheritance of rust resistance and male fertility restoration and identify the chromosome location of the underlying genes in Rf ANN-1742. Chi-squared analysis of the segregation of rust response and male fertility in F(2) and F(3) populations revealed that both traits are controlled by single dominant genes, and that the rust resistance gene is closely linked to the restorer gene in the coupling phase. The two genes were designated as R ( 11 ) and Rf5, respectively. A set of 723 mapped SSR markers of sunflower was used to screen the polymorphism between HA 89 and the resistant plant. Bulked segregant analysis subsequently located R ( 11 ) on linkage group (LG) 13 of sunflower. Based on the SSR analyses of 192 F(2) individuals, R ( 11 ) and Rf5 both mapped to the lower end of LG13 at a genetic distance of 1.6 cM, and shared a common marker, ORS728, which was mapped 1.3 cM proximal to Rf5 and 0.3 cM distal to R ( 11 ) (Rf5/ORS728/R ( 11 )). Two additional SSRs were linked to Rf5 and R ( 11 ): ORS995 was 4.5 cM distal to Rf5 and ORS45 was 1.0 cM proximal to R ( 11 ). The advantage of such an introduced alien segment harboring two genes is its large phenotypic effect and simple inheritance, thereby facilitating their rapid deployment in sunflower breeding programs. Suppressed recombination was observed in LGs 2, 9

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...

Mapping and characterization of the new adult plant leaf rust resistance gene Lr77 derived from Santa Fe winter wheat.

Science.gov (United States)

Kolmer, James A; Su, Zhenqi; Bernardo, Amy; Bai, Guihua; Chao, Shiaoman

2018-04-25

A new gene for adult plant leaf rust resistance in wheat was mapped to chromosome 3BL. This gene was designated as Lr77. 'Santa Fe' is a hard red winter cultivar that has had long-lasting resistance to the leaf rust fungus, Puccinia triticina. The objective of this study was to determine the chromosome location of the adult plant leaf rust resistance in Santa Fe wheat. A partial backcross line of 'Thatcher' (Tc) wheat with adult plant leaf rust resistance derived from Santa Fe was crossed with Thatcher to develop a Thatcher//Tc*2/Santa Fe F 6 recombinant inbred line (RIL) population. The RIL population and parental lines were evaluated for segregation of leaf rust resistance in three field plot tests and in an adult plant greenhouse test. A genetic map of the RIL population was constructed using 90,000 single-nucleotide polymorphism (SNP) markers with the Illumina Infinium iSelect 90K wheat bead array. A significant quantitative trait locus for reduction of leaf rust severity in all four tests was found on chromosome 3BL that segregated as a single adult plant resistance gene. The RILs with the allele from the resistant parent for SNP marker IWB10344 had lower leaf rust severity and a moderately resistant to moderately susceptible response compared to the susceptible RILs and Thatcher. The gene derived from Santa Fe on chromosome 3BL was designated as Lr77. Kompetitive allele-specific polymerase chain reaction assay markers linked to Lr77 on 3BL should be useful for selection of wheat germplasm with this gene.

Improvement of resistance to rust through recurrent selection in pearl millet

Energy Technology Data Exchange (ETDEWEB)

Tapsoba, H. [Univ. of Georgia, Athens, GA (United States); Wilson, J.P.; Hanna, W.W. [Univ. of Georgia Coastal Plain Experimental Station, Tifton, GA (United States)

1997-04-01

Two pearl millet [Pennisetum glaucum (L.) R.Br. = P. typhoides (Burm.) Staff & Hubb., P. americanum (L.) K. Schum.] bulk populations, Tift No. 2 and Tift No. 5, served as base populations for four cycles of recurrent selection against susceptibility to Puccinia substriata Ell. & Barth, var. indica Ramachar & Cumm. A bulk inoculum of the pathogen was used. The objectives were to evaluate the progress achieved regarding overall resistance to the pathogen in the field and resistance to different races of the pathogen, and also to evaluate changes in unselected traits. During selection, the frequency of rust resistant plants continuously increased from about 30% in each base population to more than 85% by the third cycle of selection in both populations. An average increase of about 21 and 18% per cycle was obtained in Tift No. 2 and Tift No. 5, respectively. A continuous increase of the frequency of plants resistant to some races of the pathogen was also obtained. In Tift No. 5, 80% of the plants were resistant to eight races by the third cycle of selection. The accumulation of resistance observed in the seedlings was manifested in the field, both in 1993 and 1994, by a reduction of the final rust severity from the base population to the fourth selection cycle of both populations. This improvement in resistance to the rust pathogen was accompanied by an increase in the frequency of plants resistant to Pyricularia grisea (Cooke) Sacc. only in Tift No. 2. Despite the improvement in the selected character, genetic variability for agronomic traits such as plant height, number of culms/plant, flowering date, and panicle length was successfully maintained within each population. 20 refs., 1 fig., 7 tabs.

X-ray diffraction analysis of rust layer on a weathering steel bridge with surface treatment using synchrotron radiation

International Nuclear Information System (INIS)

Yamashita, Masato; Hara, Shuichi; Kamimura, Takayuki; Miyuki, Hideaki; Sato, Masugu

2007-01-01

We have examined the structure of rust layer formed on a weathering steel bridge, to which the surface treatment, employing the effect of Cr 2 (SO 4 ) 3 sophisticatedly designed to form the protective goethite (α-FeOOH) rust layer which contains a certain amount of Cr, Cr-goethite, was applied in 1996, using X-ray diffraction at SPring-8 synchrotron radiation facility. It was shown that the formation of α-FeOOH was promoted and/or crystal growth of γ-FeOOH was suppressed by the surface treatment. The increase in the protective ability index (PAI) of the rust layer indicates that the protective goethite was predominantly formed under the effect of the surface treatment. In conclusion, it can be said that the surface treatment worked well to promote the formation of the protective goethite rust layer on the weathering steel bridge during the 10-year exposure. (author)

Induced resistance and gene expression in wheat against leaf rust ...

African Journals Online (AJOL)

uvp

2013-05-15

May 15, 2013 ... 2Department of Soil, Crop and Climate Sciences, University of the Free State, P.O Box ... Key words: Wheat leaf rust, induced resistance, priming, gene ..... transformation: susceptibility of transgenic Nicotiana sylvestris plants.

Emergence and Spread of New Races of Wheat Stem Rust Fungus: Continued Threat to Food Security and Prospects of Genetic Control.

Science.gov (United States)

Singh, Ravi P; Hodson, David P; Jin, Yue; Lagudah, Evans S; Ayliffe, Michael A; Bhavani, Sridhar; Rouse, Matthew N; Pretorius, Zacharias A; Szabo, Les J; Huerta-Espino, Julio; Basnet, Bhoja R; Lan, Caixia; Hovmøller, Mogens S

2015-07-01

Race Ug99 (TTKSK) of Puccinia graminis f. sp. tritici, detected in Uganda in 1998, has been recognized as a serious threat to food security because it possesses combined virulence to a large number of resistance genes found in current widely grown wheat (Triticum aestivum) varieties and germplasm, leading to its potential for rapid spread and evolution. Since its initial detection, variants of the Ug99 lineage of stem rust have been discovered in Eastern and Southern African countries, Yemen, Iran, and Egypt. To date, eight races belonging to the Ug99 lineage are known. Increased pathogen monitoring activities have led to the identification of other races in Africa and Asia with additional virulence to commercially important resistance genes. This has led to localized but severe stem rust epidemics becoming common once again in East Africa due to the breakdown of race-specific resistance gene SrTmp, which was deployed recently in the 'Digalu' and 'Robin' varieties in Ethiopia and Kenya, respectively. Enhanced research in the last decade under the umbrella of the Borlaug Global Rust Initiative has identified various race-specific resistance genes that can be utilized, preferably in combinations, to develop resistant varieties. Research and development of improved wheat germplasm with complex adult plant resistance (APR) based on multiple slow-rusting genes has also progressed. Once only the Sr2 gene was known to confer slow rusting APR; now, four more genes-Sr55, Sr56, Sr57, and Sr58-have been characterized and additional quantitative trait loci identified. Cloning of some rust resistance genes opens new perspectives on rust control in the future through the development of multiple resistance gene cassettes. However, at present, disease-surveillance-based chemical control, large-scale deployment of new varieties with multiple race-specific genes or adequate levels of APR, and reducing the cultivation of susceptible varieties in rust hot-spot areas remains the best

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)

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.

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

Indian Academy of Sciences (India)

Seedling resistance is usually race-specific, but often pro- vides complete ... Genomic DNA was extracted using the CTAB method of. Saghai-Maroof ... Polymerase chain reactions (PCR) were performed in ..... The continuous supply of the rust ...

Influence of Environmental Conditions and Genetic Background of Arabica Coffee (C. arabica L) on Leaf Rust (Hemileia vastatrix) Pathogenesis.

Science.gov (United States)

Toniutti, Lucile; Breitler, Jean-Christophe; Etienne, Hervé; Campa, Claudine; Doulbeau, Sylvie; Urban, Laurent; Lambot, Charles; Pinilla, Juan-Carlos H; Bertrand, Benoît

2017-01-01

Global warming is a major threat to agriculture worldwide. Between 2008 and 2013, some coffee producing countries in South and Central America suffered from severe epidemics of coffee leaf rust (CLR), resulting in high economic losses with social implications for coffee growers. The climatic events not only favored the development of the pathogen but also affected the physiological status of the coffee plant. The main objectives of the study were to evaluate how the physiological status of the coffee plant modified by different environmental conditions impact on the pathogenesis of CLR and to identify indicators of the physiological status able to predict rust incidence. Three rust susceptible genotypes (one inbred line and two hybrids) were grown in controlled conditions with a combination of thermal regime (TR), nitrogen and light intensity close to the field situation before being inoculated with the rust fungus Hemileia vastatrix . It has been demonstrated that a TR of 27-22°C resulted in 2000 times higher sporulation than with a TR of 23-18°C. It has been also shown that high light intensity combined with low nitrogen fertilization modified the CLR pathogenesis resulting in huge sporulation. CLR sporulation was significantly lower in the F1 hybrids than in the inbred line. The hybrid vigor may have reduced disease incidence. Among the many parameters studied, parameters related to photosystem II and photosynthetic electron transport chain components appeared as indicators of the physiological status of the coffee plant able to predict rust sporulation intensity. Taken together, these results show that CLR sporulation not only depends on the TR but also on the physiological status of the coffee plant, which itself depends on agronomic conditions. Our work suggests that vigorous varieties combined with a shaded system and appropriate nitrogen fertilization should be part of an agro-ecological approach to disease control.

Characterization of the symptoms of sugarcane orange rust (Puccinia kuehnii (W. Kruger E. J. Butler in four sugarcane cultivars in Cuba

Directory of Open Access Journals (Sweden)

Osmany de la Caridad Aday Díaz

2017-07-01

Full Text Available The characterization of the symptoms of the orange rust was carried out on the Sugar Cane Research Territorial Station (ETICA Centro Villa Clara, of the Sugarcane Research Institute (INICA in Cuba. Ten infected stalks of the cultivars B52107, CSG398-92, C01-227 and Clon218-2011 were evaluated. With a photographic camera the image of the three thirds of 236 leaves infected was captured on a squared paper with well-known distances. By means of the processing of images ImageJ® 1.43u the Affected Foliate Area (AFA was determined to in each third and of the complete leaf, later on the long, wide and area occupied by 554 pustules of the P. kuehnii. In the leaves from +3 at +7 were the intermediate values of AFA for P. kuehnii and this it was significantly major in the superior third of the leaves and minor in the basal part. The most frequent dimensions in the pustules of P. kuehnii reached the length understood between 0.75 and 3.0 mm, between 0.24 and 0.61 mm wide and an area of 1.39 mm2, with differences among cultivars. The emergency of the pustules was generally presented in to add form and with collapsed areas of 2.97 mm2 to 979.8 mm2.

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...

Use of AFLP marker system on sugarcane somaclones to study their resistance to rust

OpenAIRE

María Ileana Oloriz; Luis Rojas; Víctor Gil; Milady Mendoza; Ariel Arencibia; Elva Rosa Carmona; Elio Jiménez

2002-01-01

AFLPs (amplified fragment length polymorphism) was carried out from genomic DNA of five rust resistant sugar cane somaclons and their susceptible donor, Saccharum officinarum var B 4362, using three combinations of primers (EcoRI/aca: MseI/acc; EcoRI/aca: MseI/atg and EcoRI/aca: MseI/agg). Six polymorphic bands were obtained, two of these only appeared in the resistant genotypes, which are probably DNA sequences, related to rust resistance locus. These fragments have been cloned to study thei...

On W1+∞ 3-algebra and integrable system

Directory of Open Access Journals (Sweden)

Min-Ru Chen

2015-02-01

Full Text Available We construct the W1+∞ 3-algebra and investigate its connection with the integrable systems. Since the W1+∞ 3-algebra with a fixed generator W00 in the operator Nambu 3-bracket recovers the W1+∞ algebra, it is intrinsically related to the KP hierarchy. For the general case of the W1+∞ 3-algebra, we directly derive the KP and KdV equations from the Nambu–Poisson evolution equation with the different Hamiltonian pairs of the KP hierarchy. Due to the Nambu–Poisson evolution equation involves two Hamiltonians, the deep relationship between the Hamiltonian pairs of KP hierarchy is revealed. Furthermore we give a realization of the W1+∞ 3-algebra in terms of a complex bosonic field. Based on the Nambu 3-brackets of the complex bosonic field, we derive the (generalized nonlinear Schrödinger equation and give an application in optical soliton.

Identification of a green rust mineral in a reductomorphic soil by Mossbauer and Raman spectroscopies

Science.gov (United States)

Trolard, F.; Génin, J.-M. R.; Abdelmoula, M.; Bourrié, G.; Humbert, B.; Herbillon, A.

1997-03-01

Mössbauer and Raman spectroscopies are used to identify for the first time a green rust as a mineral in a reductomorphic soil from samples extracted in the forest of Fougères (Brittany-France). The Mossbauer spectrum displays two characteristic ferrous and ferric quadrupole doublets, the abundance ratio Fe(II)/Fe(Ill) of which is close to 1. Comparison with synthetic mixed valence Fe(II)Fe(HI) hydroxides supports the conclusion that the most probable formula is Fe2(OH)5, i.e., according to the pyroaurite-like crystal structure [Fe(n1Fe1III)(OH),]+o [OH] -. The microprobe Raman spectrum exhibits two bands at 518 and 427 cm-' as for synthetic green rusts. When exposed to the air, the new mineral goes rapidly from bluish-green to ochrous. The formula is compatible with the values of ionic activity products Q for equilibria between aqueous iron species and minerals obtained from soil waters, which suggests that this new mineral is likely to control the mobility of Fe in the environment.

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)

Thallium-rich rust scales in drinkable water distribution systems: A case study from northern Tuscany, Italy.

Science.gov (United States)

Biagioni, Cristian; D'Orazio, Massimo; Lepore, Giovanni O; d'Acapito, Francesco; Vezzoni, Simone

2017-06-01

Following the detection of a severe thallium contamination of the drinkable water from the public distribution system of Valdicastello Carducci-Pietrasanta (northern Tuscany, Italy), and the identification of the source of contamination in the Molini di Sant'Anna spring (average Tl content≈15μgL -1 ), the replacement of the contaminated water with a virtually Tl-free one (Tlwater. This suggested that the pipeline interior had become a secondary source of Tl contamination, promoting its mineralogical and geochemical study. Rust scales samples taken from several pipeline segments, as well as leaching products obtained from these samples, were investigated through scanning electron microscopy, X-ray fluorescence chemical analyses, inductively coupled plasma - mass spectrometry, X-ray diffraction, and X-ray absorption spectroscopy. Thallium-rich rust scales (up to 5.3wt% Tl) have been found only in pipeline samples taken downstream the water treatment plant, whereas the sample taken upstream contains much less Tl (~90μgg -1 ). The Tl-rich nature of such scales is related to the occurrence of nano- and micro-spherules of Tl 2 O 3 and less abundant nanocrystalline μm-sized encrustations of TlCl. Leaching experiments on Tl-rich rust scales indicate that a fraction of the available Tl is easily dissolved in tap water; X-ray absorption spectroscopy suggests that monovalent thallium occurs in water equilibrated with the rust scales, probably related to the dissolution of TlCl encrustations. Therefore, Tl dissolved as Tl + only in the water from the Molini di Sant'Anna spring was partially removed through oxidative precipitation of Tl 2 O 3 and precipitation of TlCl. This highlights the critical role played by the addition of chlorine-based oxidants in water treatment plants that could favour the deposition of Tl-rich coatings within the pipelines, giving rise to unexpected secondary sources of contamination. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of sugarcane introgression lines for resistance to brown rust disease caused by Puccinia melanocephala

OpenAIRE

Wang, Xiao-Yan; Wen-Feng, Li; Ying-Kun, Huang; Xin, Lu; Zhi-Ming, Luo; Jiong, Yin; Hong-Li, Shan; Rong-Yue, Zhang

2013-01-01

Sugarcane brown rust disease caused by Puccinia melanocephala is one of the important fungal diseases affecting sugarcane yield around the world. Cultivar resistance is the most appropriate control method for this disease. In this study, 62 introgression lines chosen from the crossing Saccharum officinarum L. cv. Ludashi x Erianthus rockii Yunnan 95-19 were evaluated for brown rust resistance using artificial inoculation. More than 30% of the introgression lines were identified as resistant. ...

Characterization of rust layer formed on Fe, Fe-Ni and Fe-Cr alloys exposed to Cl-rich environment by Cl and Fe K-edge XANES measurements

International Nuclear Information System (INIS)

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

2005-01-01

Chloride in atmosphere considerably reduces the corrosion resistance of conventional weathering steel containing a small amount of Cr. Ni is an effective anticorrosive element for improving the corrosion resistance of steel in a Cl-rich environment. In order to clarify the structure of the protective rust layer of weathering steel, Cl and Fe K-edge X-ray absorption near edge structure (XANES) spectra of atmospheric corrosion products (rust) formed on Fe, Fe-Ni and Fe-Cr alloys exposed to Cl-rich atmosphere were measured. The Fe K-XANES measurements enable the characterization of mixture of iron oxides such as rust. The chemical composition of the rust was determined by performing pattern fitting of the measured spectra. All the rust is composed mainly of goethite, akaganeite, lepidocrocite and magnetite. Among these iron oxides, akaganeite in particular is the major component in the rust. Additionally, the amount of akaganeite in the rust of Fe-Ni alloy is much greater than that in rust of Fe-Cr alloy. Akaganeite is generally considered to facilitate the corrosion of steel, but our results indicate that akaganeite in the rust of Fe-Ni alloy is quantitatively different from that in rust of Fe-Cr alloy and does not facilitate the corrosion of steel. The shoulder peak observed in Cl K-XANES spectra reveals that the rust contains a chloride other than akaganeite. The energy of the shoulder peak does not correspond to that of any well-known chlorides. In the measured spectra, there is no proof that Cl, by combining with the alloying element, inhibits the alloying element from acting in corrosion resistance. The shoulder peak appears only when the content of the alloying element is lower than a certain value. This suggests that the generation of the unidentified chloride is related to the corrosion rate of steel. (author)

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.

Induced mutants in beans and peas resistant to rust

International Nuclear Information System (INIS)

Fadl, F.A.M.

1983-01-01

Beans (Phaseolus vulgaris) and peas (Pisum sativum) are important leguminous vegetable crops in Egypt. The area planted with beans is about 40,000 acres and peas 22,000 acres. These crops suffer from several diseases, particularly rusts, (Uromyces phaseoli/Uromyces pisi), which are mainly spread in northern Egypt. In our mutation induction programme we used 60 Co gamma rays and ethyl methane sulphonate (EMS). Bean and pea seeds were soaked in water for two hours before exposure to 8, 10 and 12 krad. For chemical treatments, bean and pea seeds were soaked in water for eight hours and then treated with 0.5 and 1.5% EMS for four hours. The M 1 was cultivated in 1978

Risk assessment with current deployment strategies for fusiform rust-resistant loblolly and slash pines

Science.gov (United States)

Floyd Bridgwater; Tom Kubisiak; Tom Byram; Steve Mckeand

2004-01-01

In the southeastern USA, fusiform rust resistant loblolly and slash pines may be deployed as 1) ulked seed orchard mixes. 2) half-sibling (sib) family mixtures. 3) single half-sib families. 4) full-sib cross seeds or as 6) clones of individual genotypes. These deployment types are respectively greater genetic gains from higher selection intensity. Currently, bulked...

Adult plant leaf rust resistance derived from Toropi wheat is conditioned by Lr78 and three minor QTL

Science.gov (United States)

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...

White pine blister rust in Korea, Japan and other Asian regions: comparisons and implications for North America

Science.gov (United States)

M.-S. Kim; N. B. Klopfenstein; Y. Ota; S. K. Lee; K.-S. Woo; S. Kaneko

2010-01-01

This article briefly reviews the history of white pine blister rust, attributed to Cronartium ribicola, and addresses current research and management issues in South Korea, Japan and other regions of eastern Asia (China, Russia and Himalaya). For each region, the distribution, damage, aecial hosts, telial hosts and management of C. ribicola and other blister rust fungi...

Relative Fusiform Rust Resistance of Loblolly and Slash Pine Sources and Families in Georgia and South Carolina

Science.gov (United States)

E. George Kuhlman; Harry R. Powers; William D. Pepper

1995-01-01

Loblolly and slash pine seedlings from the fusiform rust resistant orchards developed cooperatively by the USDA Forest Service and the Georgia Forestry Commission had significantly less rust 7 to 8 years after planting on four of five sites in the Southeastern United States than seedlings of the same species from orchard sources developed primarily for silvicultural...

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...

QTL-seq approach identified genomic regions and diagnostic markers for rust and late leaf spot resistance in groundnut (Arachis hypogaea L.).

Science.gov (United States)

Pandey, Manish K; Khan, Aamir W; Singh, Vikas K; Vishwakarma, Manish K; Shasidhar, Yaduru; Kumar, Vinay; Garg, Vanika; Bhat, Ramesh S; Chitikineni, Annapurna; Janila, Pasupuleti; Guo, Baozhu; Varshney, Rajeev K

2017-08-01

Rust and late leaf spot (LLS) are the two major foliar fungal diseases in groundnut, and their co-occurrence leads to significant yield loss in addition to the deterioration of fodder quality. To identify candidate genomic regions controlling resistance to rust and LLS, whole-genome resequencing (WGRS)-based approach referred as 'QTL-seq' was deployed. A total of 231.67 Gb raw and 192.10 Gb of clean sequence data were generated through WGRS of resistant parent and the resistant and susceptible bulks for rust and LLS. Sequence analysis of bulks for rust and LLS with reference-guided resistant parent assembly identified 3136 single-nucleotide polymorphisms (SNPs) for rust and 66 SNPs for LLS with the read depth of ≥7 in the identified genomic region on pseudomolecule A03. Detailed analysis identified 30 nonsynonymous SNPs affecting 25 candidate genes for rust resistance, while 14 intronic and three synonymous SNPs affecting nine candidate genes for LLS resistance. Subsequently, allele-specific diagnostic markers were identified for three SNPs for rust resistance and one SNP for LLS resistance. Genotyping of one RIL population (TAG 24 × GPBD 4) with these four diagnostic markers revealed higher phenotypic variation for these two diseases. These results suggest usefulness of QTL-seq approach in precise and rapid identification of candidate genomic regions and development of diagnostic markers for breeding applications. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Mapping and characterization of wheat stem rust resistance genes SrTm5 and Sr60 from Triticum monococcum

Science.gov (United States)

The emergence and spread of new virulent races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici; Pgt), including the TTKSK (Ug99) race group, is a serious threat to global wheat production. In this study, we mapped and characterized two stem rust resistance genes from diploid wheat ...

Genomic Selection for Quantitative Adult Plant Stem Rust Resistance in Wheat

Directory of Open Access Journals (Sweden)

Jessica E. Rutkoski

2014-11-01

Full Text Available Quantitative adult plant resistance (APR to stem rust ( f. sp. is an important breeding target in wheat ( L. and a potential target for genomic selection (GS. To evaluate the relative importance of known APR loci in applying GS, we characterized a set of CIMMYT germplasm at important APR loci and on a genome-wide profile using genotyping-by-sequencing (GBS. Using this germplasm, we describe the genetic architecture and evaluate prediction models for APR using data from the international Ug99 stem rust screening nurseries. Prediction models incorporating markers linked to important APR loci and seedling phenotype scores as fixed effects were evaluated along with the classic prediction models: Multiple linear regression (MLR, Genomic best linear unbiased prediction (G-BLUP, Bayesian Lasso (BL, and Bayes Cπ (BCπ. We found the region to play an important role in APR in this germplasm. A model using linked markers as fixed effects in G-BLUP was more accurate than MLR with linked markers (-value = 0.12, and ordinary G-BLUP (-value = 0.15. Incorporating seedling phenotype information as fixed effects in G-BLUP did not consistently increase accuracy. Overall, levels of prediction accuracy found in this study indicate that GS can be effectively applied to improve stem rust APR in this germplasm, and if genotypes at linked markers are available, modeling these genotypes as fixed effects could lead to better predictions.

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

African Journals Online (AJOL)

Thirty durum wheat (19 commercial cultivars and 11 breeding lines) and 30 bread wheat (20 commercial cultivars and 10 breeding lines) were tested for gene postulation. Stem rust infection types produced on wheat cultivars and breeding lines by ten Pgt races was compared with infection types produced on 40 near ...

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...

Study of the mechanisms of humidity-induced adhesion loss of chlorinated rubber on cleaned and rusted steel substrates

International Nuclear Information System (INIS)

Chico, B.; Feliu, S.

1998-01-01

The effect of time of exposure to the humidity on the behaviour of the system chlorinated rubber paint-steel substrate (cleaned or pre-rusted) is investigated from the interfacial chemistry and adhesion points of view. After one day of humidity exposure, the paint-rust free steel substrate system shows an increase of adhesion. A maximum adhesion value is obtained after 15 days of exposure. This behaviour is similar to that previously described for a pre-rusted steel substrate. After 30-60 days of exposure, the adhesion strength values show an important reduction and the locus of adhesion loss shifts from the paint inside to the interphase between the metallic substrate and the paint. (Author) 4 refs

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.

Air permeability of the artificially synthesized Zn-Al-Mg alloy rusts

International Nuclear Information System (INIS)

Ishikawa, Tatsuo; Ueda, Masato; Kandori, Kazuhiko; Nakayama, Takenori

2007-01-01

The rust particles of Zn-Al-Mg alloys were synthesized from aqueous solutions dissolving ZnCl 2 , AlCl 3 , and MgCl 2 at different atomic ratios of the metal ions. The crystal phase and particle morphology of the products depended on the composition of the starting solutions. The compactness of the layers of the products was estimated by measuring their air permeability. The layer of mixed metal hydroxide chloride formed at Zn:Al:Mg = 1:1:1 showed a highest compactness, that was ascribed to the preferred orientation of the fine plate particles. The addition of Mg(II) made plate particles smaller to give more compact layers

Antibiotic Treatment of Blister Rust Cankers in Eastern White Pine

Science.gov (United States)

William R. Phelps; Ray Weber

1970-01-01

Cycloheximide (Acti-dione) and Phytoactin antibiotics, applied as basal stem treatments, aerial spray treatments, and complete foliar drenches were not effective in controlling blister rust cankers in eastern white pine. Cycloheximide was effective in suppressing canker activity and growth if directly applied to scarified cankers.

Cytological and molecular analysis of nonhost resistance in rice to wheat powdery mildew and leaf rust pathogens.

Science.gov (United States)

Cheng, Yulin; Yao, Juanni; Zhang, Hongchang; Huang, Lili; Kang, Zhensheng

2015-07-01

Cereal powdery mildews caused by Blumeria graminis and cereal rusts caused by Puccinia spp. are constant disease threats that limit the production of almost all important cereal crops. Rice is an intensively grown agricultural cereal that is atypical because of its immunity to all powdery mildew and rust fungi. We analyzed the nonhost interactions between rice and the wheat powdery mildew fungus B. graminis f. sp. tritici (Bgt) and the wheat leaf rust fungus Puccinia triticina (Ptr) to identify the basis of nonhost resistance (NHR) in rice against cereal powdery mildew and rust fungi at cytological and molecular levels. No visible symptoms were observed on rice leaves inoculated with Bgt or Ptr. Microscopic observations showed that both pathogens exhibited aberrant differentiation and significantly reduced penetration frequencies on rice compared to wheat. The development of Bgt and Ptr was also completely arrested at early infection stages in cases of successful penetration into rice leaves. Attempted infection of rice by Bgt and Ptr induced similar defense responses, including callose deposition, accumulation of reactive oxygen species, and hypersensitive response in rice epidermal and mesophyll cells, respectively. Furthermore, a set of defense-related genes were upregulated in rice against Bgt and Ptr infection. Rice is an excellent monocot model for genetic and molecular studies. Therefore, our results demonstrate that rice is a useful model to study the mechanisms of NHR to cereal powdery mildew and rust fungi, which provides useful information for the development of novel and durable strategies to control these important pathogens.

Effect of gelation of inner dispersed phase on stability of (w1/o/w2) multiple emulsions

NARCIS (Netherlands)

Oppermann, A.K.L.; Renssen, M.; Schuch, A.; Stieger, M.A.; Scholten, E.

2015-01-01

The use of water-in-oil-in-water (w1/o/w2) multiple emulsions offers a method for the reduction of oil in foods. In this study we investigated the influence of osmotic pressure tailoring and gelation of the inner dispersed w1 water droplets on the stability and yield of multiple emulsions. Yield is

Characteristics of Blister Rust Cankers on Eastern White Pine

Science.gov (United States)

William R. Phelps; Ray Weber

1969-01-01

The growth, development, and sporulation of white pine blister rust cankers were studied on eastern white pine in Wisconsin and Minnesota. Three district canker types were identified on the basis of physical appearance, growth rate, and sporulation. Canker growth rate and sporulation decreased as tree size or age increased, and many cankers apparently became inactive...

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...

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 ...

White pine blister rust resistance of 12 western white pine families at three field sites in the Pacific Northwest

Science.gov (United States)

Richard A. Sniezko; Robert Danchok; Jim Hamlin; Angelia Kegley; Sally Long; James Mayo

2012-01-01

Western white pine (Pinus monticola Douglas ex D. Don) is highly susceptible to the non-native, invasive pathogen Cronartium ribicola, the causative agent of white pine blister rust. The susceptibility of western white pine to blister rust has limited its use in restoration and reforestation throughout much of western North...

Production of Basella plants resistant to rust by irradiation of seeds and vegetative tissue

International Nuclear Information System (INIS)

Makambila, C.

1997-01-01

Basella is classified in the family Chenopodiaceae or Basellaceae. Also known as African spinach, this plant is consumed in Central Africa and several other African countries. There are two types of varieties grown in Congo: i. a local variety characterized by red leaves and stalks in which the principal way of propagation is from cuttings; ii. a group of varieties which have green or purple leaves and stalks. These varieties are called Basella alba and Basella rubra. These varieties have sexual reproduction. Among the two groups of varieties, the local variety is propagated vegetatively but is resistant to rust, while varieties with green leaves or with purple leaves (B. alba and B. rubra) that are propagated from seed are susceptible to rust. Since hybrid cannot be made by conventional crossing, the following procedures have been adopted to produce plants with disease tolerance: 1. production of resistant variants by irradiation of Basella alba seeds with Cesium 137; 2. production of resistant variants by irradiation of vegetative tissues obtained by culture of meristematic cells of B alba; and 3. obtaining resistant plants through somaclonal variation. 1 tab

Production of Basella plants resistant to rust by irradiation of seeds and vegetative tissue

Energy Technology Data Exchange (ETDEWEB)

Makambila, C [Laboratory of Phytopathology, Faculty of Sciences, Univ. of Brazzaville, Brazzaville (Congo)

1997-12-01

Basella is classified in the family Chenopodiaceae or Basellaceae. Also known as African spinach, this plant is consumed in Central Africa and several other African countries. There are two types of varieties grown in Congo: i. a local variety characterized by red leaves and stalks in which the principal way of propagation is from cuttings; ii. a group of varieties which have green or purple leaves and stalks. These varieties are called Basella alba and Basella rubra. These varieties have sexual reproduction. Among the two groups of varieties, the local variety is propagated vegetatively but is resistant to rust, while varieties with green leaves or with purple leaves (B. alba and B. rubra) that are propagated from seed are susceptible to rust. Since hybrid cannot be made by conventional crossing, the following procedures have been adopted to produce plants with disease tolerance: 1. production of resistant variants by irradiation of Basella alba seeds with Cesium 137; 2. production of resistant variants by irradiation of vegetative tissues obtained by culture of meristematic cells of B alba; and 3. obtaining resistant plants through somaclonal variation. 1 tab.

Sensory Description of Cultivars (Coffea Arabica L. Resistant to Rust and Its Correlation with Caffeine, Trigonelline, and Chlorogenic Acid Compounds

Directory of Open Access Journals (Sweden)

Larissa de Oliveira Fassio

2016-01-01

Full Text Available Considering the importance of the chemical compounds in Arabica coffee beans in the definition of the drink sensory quality and authentication of coffee regions, the aim of this study was to evaluate, from principal component analysis—PCA—if there is a relation between the caffeine, trigonelline, and chlorogenic acid (5-CQA content and the sensory attributes of the drink, and in this context, enabling the differentiation of cultivars in two coffee-producing regions of Brazil. We evaluated seven rust-resistant Coffea arabica cultivars, and two rust-susceptible cultivars in two cultivation environments: Lavras, in the southern region of Minas Gerais state, and Patrocinio in the Cerrado region of Minas Gerais. The flavor and acidity were determinant for differentiation of the cultivars and their interaction with the evaluated environments. Cultivars Araponga MG1, Catigua MG2, and Catigua MG1 are the most suitable for the production of specialty coffee in the state of Minas Gerais. A poor correlation was found between caffeine, trigonelline, 5-CQA contents, and fragrance, flavor, acidity, body, and final score attributes. However, these compounds enabled the differentiation of the environments. The PCA indicated superiority in the sensory quality of cultivars resistant to rust, compared to the control, Bourbon Amarelo, and Topázio MG1190.

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

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 ...

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...

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...

Prehaustorial and posthaustorial resistance to wheat leaf rust in diploid wheat

NARCIS (Netherlands)

Anker, C.C.

2001-01-01

In modern wheat cultivars, resistance to wheat leaf rust, Puccinia triticina , is either based on hypersensitivity resistance or on partial resistance. Hypersensitivity resistance in wheat is monogenic, often complete and posthaustorial: it is induced after the

Studies of the genetics of inheritance of stem rust resistance in ...

African Journals Online (AJOL)

User

2013-05-22

May 22, 2013 ... increased production of wheat could help to ensure food and nutritional ... also characterized by genes with additive effects and non hypersensitive .... to create an artificial stem rust epidemic in the field (Hickey et al.,. 2012 ...

QTL mapping provides evidence for lack of association of the avoidance of leaf rust in Hordeum chilense with stomata density

NARCIS (Netherlands)

Vaz Patto, M.C.; Rubiales, D.; Martin, A.; Hernandez, P.; Lindhout, W.H.; Niks, R.E.; Stam, P.

2003-01-01

In cereals, rust fungi are among the most harmful pathogens. Breeders usually rely on short-lived hypersensitivity resistance. As an alternative, "avoidance" may be a more durable defence mechanism to protect plants to rust fungi. In Hordeum chilense avoidance is based on extensive wax covering of

Transcriptomic characterization of MRI contrast with focus on the T1-w/T2-w ratio in the cerebral cortex.

Science.gov (United States)

Ritchie, Jacob; Pantazatos, Spiro P; French, Leon

2018-07-01

Magnetic resonance (MR) images of the brain are of immense clinical and research utility. At the atomic and subatomic levels, the sources of MR signals are well understood. However, we lack a comprehensive understanding of the macromolecular correlates of MR signal contrast. To address this gap, we used genome-wide measurements to correlate gene expression with MR signal intensity across the cerebral cortex in the Allen Human Brain Atlas (AHBA). We focused on the ratio of T1-weighted and T2-weighted intensities (T1-w/T2-w ratio image), which is considered to be a useful proxy for myelin content. As expected, we found enrichment of positive correlations between myelin-associated genes and the ratio image, supporting its use as a myelin marker. Genome-wide, there was an association with protein mass, with genes coding for heavier proteins expressed in regions with high T1-w/T2-w values. Oligodendrocyte gene markers were strongly correlated with the T1-w/T2-w ratio, but this was not driven by myelin-associated genes. Mitochondrial genes exhibit the strongest relationship, showing higher expression in regions with low T1-w/T2-w ratio. This may be due to the pH gradient in mitochondria as genes up-regulated by pH in the brain were also highly correlated with the ratio. While we corroborate associations with myelin and synaptic plasticity, differences in the T1-w/T2-w ratio across the cortex are more strongly linked to molecule size, oligodendrocyte markers, mitochondria, and pH. We evaluate correlations between AHBA transcriptomic measurements and a group averaged T1-w/T2-w ratio image, showing agreement with in-sample results. Expanding our analysis to the whole brain results in strong positive T1-w/T2-w correlations for immune system, inflammatory disease, and microglia marker genes. Genes with negative correlations were enriched for neuron markers and synaptic plasticity genes. Lastly, our findings are similar when performed on T1-w or inverted T2-w intensities alone

Discovery of a Novel Stem Rust Resistance Allele in Durum Wheat that Exhibits Differential Reactions to Ug99 Isolates

Directory of Open Access Journals (Sweden)

Jayaveeramuthu Nirmala

2017-10-01

Full Text Available Wheat stem rust, caused by Puccinia graminis f. sp. tritici Eriks. & E. Henn, can incur yield losses in susceptible cultivars of durum wheat, Triticum turgidum ssp. durum (Desf. Husnot. Although several durum cultivars possess the stem rust resistance gene Sr13, additional genes in durum wheat effective against emerging virulent races have not been described. Durum line 8155-B1 confers resistance against the P. graminis f. sp. tritici race TTKST, the variant race of the Ug99 race group with additional virulence to wheat stem rust resistance gene Sr24. However, 8155-B1 does not confer resistance to the first-described race in the Ug99 race group: TTKSK. We mapped a single gene conferring resistance in 8155-B1 against race TTKST, Sr8155B1, to chromosome arm 6AS by utilizing Rusty/8155-B1 and Rusty*2/8155-B1 populations and the 90K Infinium iSelect Custom bead chip supplemented by KASP assays. One marker, KASP_6AS_IWB10558, cosegregated with Sr8155B1 in both populations and correctly predicted Sr8155B1 presence or absence in 11 durum cultivars tested. We confirmed the presence of Sr8155B1 in cultivar Mountrail by mapping in the population Choteau/Mountrail. The marker developed in this study could be used to predict the presence of resistance to race TTKST in uncharacterized durum breeding lines, and also to combine Sr8155B1 with resistance genes effective to Ug99 such as Sr13. The map location of Sr8155B1 cannot rule out the possibility that this gene is an allele at the Sr8 locus. However, race specificity indicates that Sr8155B1 is different from the known alleles Sr8a and Sr8b.

The estimation of rust disease of daylily leaf images with GLCM based different classification methods

OpenAIRE

ÖZERDEM, Mehmet Siraç; ACAR, Emrullah

2011-01-01

Crop diseases can affect yield and/or quality of the harvested commodity. This can influence profitability and raise the risks of farming. When the diseases are estimated early, the yield will increase by taking measures thanks to farmers. The rust disease is one of the most major crop diseases that affect crop yield. Rust disease can be defined as a fungus; it makes the crops weak by blocking food to the roots and leaves. It is named “rust” disease, since the spots on the leaves look like gr...

Reductive and sorptive properties of sulfate green rust (GRSO4)

DEFF Research Database (Denmark)

Nedel, Sorin

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

Investigation of Non-Uniform Rust Distribution and Its Effects on Corrosion Induced Cracking in Reinforced Concrete

Directory of Open Access Journals (Sweden)

Sutrisno Wahyuniarsih

2017-01-01

Full Text Available Uniform corrosion still widely used by a lot of researchers and engineers to analyze the corrosion induced cracking. However, in practice, corrosion process occurred non-uniformly. The part nearest to the exposed surface is more likely to have faster corrosion initiation compared with other regions. This research is mainly focused on investigating the effect of non-uniform rust distribution to cover cracking in reinforced concrete. An experimental test performed using accelerated corrosion test by using 5% NaCl solution and applied a constant electric current to the concrete samples. The rust distribution and measurement were observed by using a digital microscope. Based on the experimental result, it was found that the rust was distributed in a non-uniform pattern. As a result, the cracks also formed non-uniformly along the perimeter of steel bar. At the last part of this paper, a simulation result of concrete cracking induced by non-uniform corrosion is presented. The result compared with a simulation using uniform corrosion assumption to investigate the damage pattern of each model. The simulation result reveals stress evolution due to rust expansion which leads to concrete cracking. Furthermore, a comparison of stresses induced by non-uniform corrosion and uniform corrosion indicates that non-uniform corrosion could lead to earlier damage to the structure which is specified by the formation and propagation of the crack.

β1-C121W Is Down But Not Out: Epilepsy-Associated Scn1b-C121W Results in a Deleterious Gain-of-Function

Science.gov (United States)

Kruger, Larisa C.; O'Malley, Heather A.; Hull, Jacob M.; Kleeman, Amanda; Patino, Gustavo A.

2016-01-01

Voltage-gated sodium channel (VGSC) β subunits signal through multiple pathways on multiple time scales. In addition to modulating sodium and potassium currents, β subunits play nonconducting roles as cell adhesion molecules, which allow them to function in cell–cell communication, neuronal migration, neurite outgrowth, neuronal pathfinding, and axonal fasciculation. Mutations in SCN1B, encoding VGSC β1 and β1B, are associated with epilepsy. Autosomal-dominant SCN1B-C121W, the first epilepsy-associated VGSC mutation identified, results in genetic epilepsy with febrile seizures plus (GEFS+). This mutation has been shown to disrupt both the sodium-current-modulatory and cell-adhesive functions of β1 subunits expressed in heterologous systems. The goal of this study was to compare mice heterozygous for Scn1b-C121W (Scn1b+/W) with mice heterozygous for the Scn1b-null allele (Scn1b+/−) to determine whether the C121W mutation results in loss-of-function in vivo. We found that Scn1b+/W mice were more susceptible than Scn1b+/− and Scn1b+/+ mice to hyperthermia-induced convulsions, a model of pediatric febrile seizures. β1-C121W subunits are expressed at the neuronal cell surface in vivo. However, despite this, β1-C121W polypeptides are incompletely glycosylated and do not associate with VGSC α subunits in the brain. β1-C121W subcellular localization is restricted to neuronal cell bodies and is not detected at axon initial segments in the cortex or cerebellum or at optic nerve nodes of Ranvier of Scn1bW/W mice. These data, together with our previous results showing that β1-C121W cannot participate in trans-homophilic cell adhesion, lead to the hypothesis that SCN1B-C121W confers a deleterious gain-of-function in human GEFS+ patients. SIGNIFICANCE STATEMENT The mechanisms underlying genetic epilepsy syndromes are poorly understood. Closing this gap in knowledge is essential to the development of new medicines to treat epilepsy. We have used mouse models to

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...

Simultaneous Transfer of Leaf Rust and Powdery Mildew Resistance Genes from Hexaploid Triticale Cultivar Sorento into Bread Wheat.

Science.gov (United States)

Li, Feng; Li, Yinghui; Cao, Lirong; Liu, Peiyuan; Geng, Miaomiao; Zhang, Qiang; Qiu, Lina; Sun, Qixin; Xie, Chaojie

2018-01-01

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 F 1 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 BC 2 F 3 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.

Expression of apoplast-targeted plant defensin MtDef4.2 confers resistance to leaf rust pathogen Puccinia triticina but does not affect mycorrhizal symbiosis in transgenic wheat

Science.gov (United States)

Rust diseases caused by Puccinia spp. pose a major threat to global wheat production. Puccinia triticina (Pt), an obligate basidiomycete biotroph, causes leaf rust disease which incurs yield losses of up to 50% in wheat. Historically, resistant wheat cultivars have been used to control leaf rust, bu...

Rust and schreibersite in Apollo 16 highland rocks - Manifestations of volatile-element mobility

Science.gov (United States)

Hunter, R. H.; Taylor, L. A.

Rust is a manifestation of halogen and volatile-metal mobility in the lunar environment. Schreibersite is stable as the primary phosphorus-bearing phase in the highland rocks, a consequence of the inherently low oxygen fugacity within impact-generated melts. Apatite and whitlockite are subordinate in these rocks. The partitioning of P into phosphide in impact-generated melts, and the failure of phosphate to crystallize, effects a decoupling of the halogens and phosphorus. Of the Apollo 16 rocks, 63% contain rust, 70% contain schreibersite, and 52% contain both phases, thereby establishing the pervasiveness of volatile-elements throughout the highland rocks. The major portion of these volatile-bearing phases occur in impact melt-rocks or in breccia matrices. Rhabdites of schreibersite in some of the FeNi grains indicate that there is a meteoritic contribution to the phosphorus in these rocks. Cl/P2O5 ratios in lunar highland rocks are a function of secondary effects, with any apparent Cl-P correlations being coincidential. The present observations preclude the validity of models based on such elemental ratios in these rocks. The presence of rust in the clast laden matrices of pristine rocks indicates fugitive element localization. Pristine clasts may have been contaminated. The basis for a pristine volatile chemistry is questioned.

Protection of wheat against leaf and stem rust and powdery mildew diseases by inhibition of polyamine metabolism

Science.gov (United States)

Weinstein, L. H.; Osmeloski, J. F.; Wettlaufer, S. H.; Galston, A. W.

1987-01-01

In higher plants, polyamines arise from arginine by one of two pathways: via ornithine and ornithine decarboxylase or via agmatine and arginine decarboxylase but in fungi, only the ornithine decarboxylase pathway is present. Since polyamines are required for normal growth of microorganisms and plants and since the ornithine pathway can be irreversibly blocked by alpha-difluoromethylornithine (DFMO) which has no effect on arginine decarboxylase, fungal infection of green plants might be controlled by the site-directed use of such a specific metabolic inhibitor. DFMO at relatively low concentrations provided effective control of the three biotrophic fungal pathogens studied, Puccinia recondita (leaf rust), P. graminis f. sp. tritici (stem rust), and Erysiphe graminis (powdery mildew) on wheat (Triticum aestivum L.) Effective control of infection by leaf or stem rust fungi was obtained with sprays of DFMO that ranged from about 0.01 to 0.20 mM in experiments where the inhibitor was applied after spore inoculation. The powdery mildew fungus was somewhat more tolerant of DFMO, but good control of the pathogen was obtained at less than 1.0 mM. In general, application of DFMO after spore inoculation was more effective than application before inoculation. Less control was obtained following treatment with alpha-difluoromethylarginine (DFMA) but the relatively high degree of control obtained raises the possibility of a DFMA to DFMO conversion by arginase.

Seedling Resistance to Stem Rust and Molecular Marker Analysis of Resistance Genes in Wheat Cultivars of Yunnan, China.

Directory of Open Access Journals (Sweden)

Tian Ya Li

Full Text Available Stem rust is one of the most potentially harmful wheat diseases, but has been effectively controlled in China since 1970s. However, the interest in breeding wheat with durable resistance to stem rust has been renewed with the emergence of Ug99 (TTKSK virulent to the widely used resistance gene Sr31, and by which the wheat stem rust was controlled for 40 years in wheat production area worldwide. Yunnan Province, located on the Southwest border of China, is one of the main wheat growing regions, playing a pivotal role in the wheat stem rust epidemic in China. This study investigated the levels of resistance in key wheat cultivars (lines of Yunnan Province. In addition, the existence of Sr25, Sr26, Sr28, Sr31, Sr32, and Sr38 genes in 119 wheat cultivars was assessed using specific DNA markers. The results indicated that 77 (64.7% tested wheat varieties showed different levels of resistance to all the tested races of Puccinia graminis f. sp. tritici. Using molecular markers, we identified the resistance gene Sr31 in 43 samples; Sr38 in 10 samples; Sr28 in 12 samples, and one sample which was resistant against Ug99 (avirulent to Sr32. No Sr25 or Sr26 (effective against Ug99 was identified in any cultivars tested. Furthermore, 5 out of 119 cultivars tested carried both Sr31 and Sr38 and eight contained both Sr31 and Sr28. The results enable the development of appropriate strategies to breed varieties resistant to stem rust.

Copper-mediated reductive dechlorination by green rust intercalated with dodecanoate

DEFF Research Database (Denmark)

Huang, Lizhi; Yin, Zhou; Cooper, Nicola G.A.

2018-01-01

A layered FeII-FeIII hydroxide (green rust, GR) was intercalated with dodecanoate (known as GRC12) and then amended with CuII (GRC12(Cu)) before reaction with chloroform (CF), carbon tetrachloride (CT), trichloroethylene (TCE) or tetrachloroethylene (PCE). Reduction of CT by GRC12(Cu) was 37 times...

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...

Resistance of three interspecific white pine hybrids to blister rust

Science.gov (United States)

R. Z. Callaham

1962-01-01

Three white pine hybrids exposed to infection by white pine blister rust (Cronartium ribicola Fischer) since 1946 have inherited the relative resistance of their parental species. The hybrids were produced from controlled pollinations in 1940 and 1941 at the Institute of Forest Genetics, Placerville, Calif. Twelve seedlings of each hybrid were...

High-throughput genotyping-by-sequencing facilitates molecular tagging of a novel rust resistance gene, R 15 , in sunflower (Helianthus annuus L.).

Science.gov (United States)

Ma, G J; Song, Q J; Markell, S G; Qi, L L

2018-03-21

A novel rust resistance gene, R 15 , derived from the cultivated sunflower HA-R8 was assigned to linkage group 8 of the sunflower genome using a genotyping-by-sequencing approach. SNP markers closely linked to R 15 were identified, facilitating marker-assisted selection of resistance genes. The rust virulence gene is co-evolving with the resistance gene in sunflower, leading to the emergence of new physiologic pathotypes. This presents a continuous threat to the sunflower crop necessitating the development of resistant sunflower hybrids providing a more efficient, durable, and environmentally friendly host plant resistance. The inbred line HA-R8 carries a gene conferring resistance to all known races of the rust pathogen in North America and can be used as a broad-spectrum resistance resource. Based on phenotypic assessments of 140 F 2 individuals derived from a cross of HA 89 with HA-R8, rust resistance in the population was found to be conferred by a single dominant gene (R 15 ) originating from HA-R8. Genotypic analysis with the currently available SSR markers failed to find any association between rust resistance and any markers. Therefore, we used genotyping-by-sequencing (GBS) analysis to achieve better genomic coverage. The GBS data showed that R 15 was located at the top end of linkage group (LG) 8. Saturation with 71 previously mapped SNP markers selected within this region further showed that it was located in a resistance gene cluster on LG8, and mapped to a 1.0-cM region between three co-segregating SNP makers SFW01920, SFW00128, and SFW05824 as well as the NSA_008457 SNP marker. These closely linked markers will facilitate marker-assisted selection and breeding in sunflower.

Antibiotics Do Not Control Blister Rust in Eastern White Pine Seedlings

Science.gov (United States)

William R. Phelps; Ray Weber

1968-01-01

To prevent blister rust infections in Eastern white pine seedlings, the antibiotics, cycloheximide (acti-dione) and Phytoactin, were tested in root dips, root slurries, and foliar drenches before planting and after planting the trees. None of the methods and materials tested was effective.

Green rust formation controls nutrient availability in a ferruginous water column

DEFF Research Database (Denmark)

Zegeye, Asfaw; Bonneville, Steeve; Benning, Liane G.

2013-01-01

a mechanism for reconstructing ancient ocean chemistry. Such reconstructions depend, however, on precise knowledge of the iron minerals formed in the water column. Here, we combine mineralogical and geochemical analyses to demonstrate formation of the mixed-valence iron mineral, green rust, in ferruginous...

Differential gene expression in loblolly pine (Pinus taeda L.) challenged with the fusiform rust fungus, Cronartium quercuum f.sp. fusiforme

Science.gov (United States)

Henrietta Myburg; Alison M. Morse; Henry V. Amerson; Thomas L. Kubisiak; Dudley Huber; Jason A. Osborne; Saul A. Garcia; C. Dana Nelson; John M. Davis; Sarah F. Covert; Leonel M. van Zyle

2006-01-01

Cronartium quercuum f.sp. fusiforme is the pathogen that incites fusiform rust disease of southern pine species. To date, a number of host resistance genes have been mapped. Although genomic mapping studies have provided valuable information on the genetic basis of disease interactions in this pine-rust pathosystem, the interaction...

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

Relocation of a rust resistance gene R 2 and its marker-assisted gene pyramiding in confection sunflower (Helianthus annuus L.).

Science.gov (United States)

Qi, L L; Ma, G J; Long, Y M; Hulke, B S; Gong, L; Markell, S G

2015-03-01

The rust resistance gene R 2 was reassigned to linkage group 14 of the sunflower genome. DNA markers linked to R 2 were identified and used for marker-assisted gene pyramiding in a confection type genetic background. Due to the frequent evolution of new pathogen races, sunflower rust is a recurring threat to sunflower production worldwide. The inbred line Morden Cross 29 (MC29) carries the rust resistance gene, R 2 , conferring resistance to numerous races of rust fungus in the US, Canada, and Australia, and can be used as a broad-spectrum resistance resource. Based on phenotypic assessments and SSR marker analyses on the 117 F2 individuals derived from a cross of HA 89 with MC29 (USDA), R 2 was mapped to linkage group (LG) 14 of the sunflower, and not to the previously reported location on LG9. The closest SSR marker HT567 was located at 4.3 cM distal to R 2 . Furthermore, 36 selected SNP markers from LG14 were used to saturate the R 2 region. Two SNP markers, NSA_002316 and SFW01272, flanked R 2 at a genetic distance of 2.8 and 1.8 cM, respectively. Of the three closely linked markers, SFW00211 amplified an allele specific for the presence of R 2 in a marker validation set of 46 breeding lines, and SFW01272 was also shown to be diagnostic for R 2 . These newly developed markers, together with the previously identified markers linked to the gene R 13a , were used to screen 524 F2 individuals from a cross of a confection R 2 line and HA-R6 carrying R 13a . Eleven homozygous double-resistant F2 plants with the gene combination of R 2 and R 13a were obtained. This double-resistant line will be extremely useful in confection sunflower, where few rust R genes are available, risking evolution of new virulence phenotypes and further disease epidemics.

W-curve alignments for HIV-1 genomic comparisons.

Directory of Open Access Journals (Sweden)

Douglas J Cork

2010-06-01

Full Text Available The W-curve was originally developed as a graphical visualization technique for viewing DNA and RNA sequences. Its ability to render features of DNA also makes it suitable for computational studies. Its main advantage in this area is utilizing a single-pass algorithm for comparing the sequences. Avoiding recursion during sequence alignments offers advantages for speed and in-process resources. The graphical technique also allows for multiple models of comparison to be used depending on the nucleotide patterns embedded in similar whole genomic sequences. The W-curve approach allows us to compare large numbers of samples quickly.We are currently tuning the algorithm to accommodate quirks specific to HIV-1 genomic sequences so that it can be used to aid in diagnostic and vaccine efforts. Tracking the molecular evolution of the virus has been greatly hampered by gap associated problems predominantly embedded within the envelope gene of the virus. Gaps and hypermutation of the virus slow conventional string based alignments of the whole genome. This paper describes the W-curve algorithm itself, and how we have adapted it for comparison of similar HIV-1 genomes. A treebuilding method is developed with the W-curve that utilizes a novel Cylindrical Coordinate distance method and gap analysis method. HIV-1 C2-V5 env sequence regions from a Mother/Infant cohort study are used in the comparison.The output distance matrix and neighbor results produced by the W-curve are functionally equivalent to those from Clustal for C2-V5 sequences in the mother/infant pairs infected with CRF01_AE.Significant potential exists for utilizing this method in place of conventional string based alignment of HIV-1 genomes, such as Clustal X. With W-curve heuristic alignment, it may be possible to obtain clinically useful results in a short time-short enough to affect clinical choices for acute treatment. A description of the W-curve generation process, including a comparison

W-curve alignments for HIV-1 genomic comparisons.

Science.gov (United States)

Cork, Douglas J; Lembark, Steven; Tovanabutra, Sodsai; Robb, Merlin L; Kim, Jerome H

2010-06-01

The W-curve was originally developed as a graphical visualization technique for viewing DNA and RNA sequences. Its ability to render features of DNA also makes it suitable for computational studies. Its main advantage in this area is utilizing a single-pass algorithm for comparing the sequences. Avoiding recursion during sequence alignments offers advantages for speed and in-process resources. The graphical technique also allows for multiple models of comparison to be used depending on the nucleotide patterns embedded in similar whole genomic sequences. The W-curve approach allows us to compare large numbers of samples quickly. We are currently tuning the algorithm to accommodate quirks specific to HIV-1 genomic sequences so that it can be used to aid in diagnostic and vaccine efforts. Tracking the molecular evolution of the virus has been greatly hampered by gap associated problems predominantly embedded within the envelope gene of the virus. Gaps and hypermutation of the virus slow conventional string based alignments of the whole genome. This paper describes the W-curve algorithm itself, and how we have adapted it for comparison of similar HIV-1 genomes. A treebuilding method is developed with the W-curve that utilizes a novel Cylindrical Coordinate distance method and gap analysis method. HIV-1 C2-V5 env sequence regions from a Mother/Infant cohort study are used in the comparison. The output distance matrix and neighbor results produced by the W-curve are functionally equivalent to those from Clustal for C2-V5 sequences in the mother/infant pairs infected with CRF01_AE. Significant potential exists for utilizing this method in place of conventional string based alignment of HIV-1 genomes, such as Clustal X. With W-curve heuristic alignment, it may be possible to obtain clinically useful results in a short time-short enough to affect clinical choices for acute treatment. A description of the W-curve generation process, including a comparison technique of

Use of AFLP marker system on sugarcane somaclones to study their resistance to rust

Directory of Open Access Journals (Sweden)

María Ileana Oloriz

2002-10-01

Full Text Available AFLPs (amplified fragment length polymorphism was carried out from genomic DNA of five rust resistant sugar cane somaclons and their susceptible donor, Saccharum officinarum var B 4362, using three combinations of primers (EcoRI/aca: MseI/acc; EcoRI/aca: MseI/atg and EcoRI/aca: MseI/agg. Six polymorphic bands were obtained, two of these only appeared in the resistant genotypes, which are probably DNA sequences, related to rust resistance locus. These fragments have been cloned to study their nucleotide sequence and to investigate their roll in resistance mechanism develop by these mutants during Puccinia melanocephala infection. Key words: molecular markers, Puccinia. melanocephala, Saccharum

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. ...

Growth of Legionella anisa in a model drinking water system to evaluate different shower outlets and the impact of cast iron rust.

Science.gov (United States)

van der Lugt, Wilco; Euser, Sjoerd M; Bruin, Jacob P; Den Boer, Jeroen W; Walker, Jimmy T; Crespi, Sebastian

2017-11-01

Legionella continues to be a problem in water systems. This study investigated the influence of different shower mixer faucets, and the influence of the presence of cast iron rust from a drinking water system on the growth of Legionella. The research is conducted using a model of a household containing four drinking water systems. All four systems, which contained standard plumbing components including copper pipes and a water heater, were filled with unchlorinated drinking water. Furthermore, all systems had three different shower faucets: (A) a stainless-steel faucet, (B) a brass-ceramic faucet, and (C) a brass thermostatic faucet. System 1 was solely filled with drinking water. System 2 was filled with drinking water, and cast iron rust. System 3 was contaminated with Legionella, and system 4 was contaminated with a Legionella, and cast iron rust. During a period of 34 months, 450 cold water samples were taken from 15 sample points of the four drinking water systems, and tested for Legionella according to the Dutch Standard (NEN 6265). In system 4, with added cast iron rust, the stainless-steel mixer faucet (A) had the highest concentration of Legionella at >4.3log10CFU/l (>20,000CFU/l) and was positive in 46.4% of samples. In contrast, the stainless-steel mixer faucet (A) of system 3 without cast iron rust showed 14.3% positive samples with a maximum concentration of 3.9log10CFU/l (7600CFU/l) Legionella. Additionally, both contaminated systems (3 and 4), with the brass thermostatic faucet (C), tested positive for Legionella. System 3 in 85.7% of the samples, with a maximum concentration of 4.38log10CFU/l (24,200CFU/l), and system 4 in 64.3% of the samples with a maximum concentration of 4.13log10CFU/l (13.400CFU/l). These results suggest that both the type of faucet used in a drinking water system and the presence or absence of cast iron rust influence the growth of Legionella. Copyright © 2017 Elsevier GmbH. All rights reserved.

Site-specific standard request for Underground Storage Tanks 1219-U, 1222-U, 2082-U, and 2068-U at the Rust Garage Facility Buildings 9754-1 and 9720-15

International Nuclear Information System (INIS)

1994-08-01

This document is a site-specific standard request for underground storage tanks located at the Rust Garage Facility. These standards are justified based on conclusion derived from the exposure assessment that indicates there is no current or forseeable future human health risk associated with petroleum contaminants on the site, that current and future ecological risks would be generally limited to subsurface species and plant life with roots extending into the area, and that most of the impacted area at the site is covered by asphalt or concrete. The vertical and horizontal extent of soil and ground water contamination are limited to immediate area of the Rust Garage Facility

SEASONALITY OF THE LEAF MINER, LEVEL OF PREDATION AND TEMPORAL OCCURRENCE OF RUST CORRELATED TO ABIOTIC FACTORS

OpenAIRE

B. M. R. Melo; F. B. S. Botelho; J. S. M. Silva; D. F. F. Lima; E. R. Moreira

2018-01-01

The coffee leaf miner and a rust are considered as major diseases that are able to reduce productivity in coffee plantations. These agents are influenced by abiotic factors, and their occurrence may suffer oscillation over the years. The objective of this study was to evaluate the seasonal fluctuation of the coffee leaf miner, incidence of coffee prediction and rust, correlated with abiotic factors. The study was performed IFSULDEMINAS-Campus Inconfidentes, in a coffee crop of the cultivar Ru...

Identification of RAPD marker associated with brown rust resistance in sugarcane

Science.gov (United States)

Susceptibility to brown rust caused by Puccinia melanocephala is a major reason for the withdrawal of sugarcane cultivars from production. An efficient way to control the disease is to breed cultivars with durable resistance. Our aim was to identify random amplified polymorphic DNA (RAPD) markers ...

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

Measurement of the W(+)W(-) production cross section in pp collisions at square root[s]=1.96 TeV using dilepton events.

Science.gov (United States)

Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Arguin, J-F; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barker, G J; Barnes, V E; Barnett, B A; Baroiant, S; Barone, M; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Ben-Haim, E; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bishai, M; Blair, R E; Blocker, C; Bloom, K; Blumenfeld, B; Bocci, A; Bodek, A; Bolla, G; Bolshov, A; Booth, P S L; Bortoletto, D; Boudreau, J; Bourov, S; Brau, B; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Casarsa, M; Carlsmith, D; Carron, S; Carosi, R; Cavalli-Sforza, M; Castro, A; Catastini, P; Cauz, D; Cerri, A; Cerrito, L; Chapman, J; Chen, C; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Chu, M L; Chuang, S; Chung, J Y; Chung, W-H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A G; Clark, D; Coca, M; Connolly, A; Convery, M; Conway, J; Cooper, B; Cordelli, M; Cortiana, G; Cranshaw, J; Cuevas, J; Culbertson, R; Currat, C; Cyr, D; Dagenhart, D; Da Ronco, S; D'Auria, S; de Barbaro, P; De Cecco, S; De Lentdecker, G; Dell'agnello, S; Dell'orso, M; Demers, S; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Dionisi, C; Dittmann, J R; Dörr, C; Doksus, P; Dominguez, A; Donati, S; Donega, M; Donini, J; D'Onofrio, M; Dorigo, T; Drollinger, V; Ebina, K; Eddy, N; Efron, J; Ehlers, J; Ely, R; Erbacher, R; Erdmann, M; Errede, D; Errede, S; Eusebi, R; Fang, H-C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferretti, C; Field, R D; Flanagan, G; Flaugher, B; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Fujii, Y; Furic, I; Gajjar, A; Gallas, A; Galyardt, J; Gallinaro, M; Garcia-Sciveres, M; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D W; Gerchtein, E; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giolo, K; Giordani, M; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, D; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grosso-Pilcher, C; Grundler, U; Guenther, M; Guimaraes da Costa, J; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harr, R F; Harris, R M; Hartmann, F; Hatakeyama, K; Hauser, J; Hays, C; Hayward, H; Heider, E; Heinemann, B; Heinrich, J; Hennecke, M; Herndon, M; Hill, C; Hirschbuehl, D; Hocker, A; Hoffman, K D; Holloway, A; Hou, S; Houlden, M A; Huffman, B T; Huang, Y; Hughes, R E; Huston, J; Ikado, K; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Issever, C; Ivanov, A; Iwata, Y; Iyutin, B; James, E; Jang, D; Jarrell, J; Jeans, D; Jensen, H; Jeon, E J; Jones, M; Joo, K K; Jun, S Y; Junk, T; Kamon, T; Kang, J; Karagoz Unel, M; Karchin, P E; Kartal, S; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, M S; Kim, S B; Kim, S H; Kim, T H; Kim, Y K; Kirby, M; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kobayashi, H; Koehn, P; Kong, D J; Kondo, K; Konigsberg, J; Kordas, K; Korn, A; Korytov, A; Kotelnikov, K; Kotwal, A V; Kovalev, A; Kraus, J; Kravchenko, I; Kreymer, A; Kroll, J; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, J; Lancaster, M; Lander, R; Lannon, K; Lath, A; Latino, G; Lauhakangas, R; Lazzizzera, I; Le, Y; Lecci, C; Lecompte, T; Lee, J; Lee, J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Li, K; Lin, C; Lin, C S; Lindgren, M; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Liu, Y; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Macqueen, D; Madrak, R; Maeshima, K; Maksimovic, P; Malferrari, L; Manca, G; Marginean, R; Marino, C; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Matsunaga, H; Mattson, M; Mazzanti, P; McFarland, K S; McGivern, D; McIntyre, P M; McNamara, P; McNulty, R; Mehta, A; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miller, L; Miller, R; Miller, J S; Mills, C; Miquel, R; Miscetti, S; Mitselmakher, G; Miyamoto, A; Miyazaki, Y; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P A; Mukherjee, A; Mulhearn, M; Muller, T; Mumford, R; Munar, A; Murat, P; Nachtman, J; Nahn, S; Nakamura, I; Nakano, I; Napier, A; Napora, R; Naumov, D; Necula, V; Niell, F; Nielsen, J; Nelson, C; Nelson, T; Neu, C; Neubauer, M S; Newman-Holmes, C; Nigmanov, T; Nodulman, L; Norniella, O; Oesterberg, K; Ogawa, T; Oh, S H; Oh, Y D; Ohsugi, T; Okusawa, T; Oldeman, R; Orava, R; Orejudos, W; Pagliarone, C; Palencia, E; Paoletti, R; Papadimitriou, V; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Pauly, T; Paus, C; Pellett, D; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pitts, K T; Plager, C; Pompos, A; Pondrom, L; Pope, G; Portell, X; Poukhov, O; Prakoshyn, F; Pratt, T; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Rademacker, J; Rahaman, M A; Rakitine, A; Rappoccio, S; Ratnikov, F; Ray, H; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Rimondi, F; Rinnert, K; Ristori, L; Robertson, W J; Robson, A; Rodrigo, T; Rolli, S; Rosenson, L; Roser, R; Rossin, R; Rott, C; Russ, J; Rusu, V; Ruiz, A; Ryan, D; Saarikko, H; Sabik, S; Safonov, A; St Denis, R; Sakumoto, W K; Salamanna, G; Saltzberg, D; Sanchez, C; Sansoni, A; Santi, L; Sarkar, S; Sato, K; Savard, P; Savoy-Navarro, A; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semeria, F; Sexton-Kennedy, L; Sfiligoi, I; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Siegrist, J; Siket, M; Sill, A; Sinervo, P; Sisakyan, A; Skiba, A; Slaughter, A J; Sliwa, K; Smirnov, D; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S V; Spalding, J; Spezziga, M; Spiegel, L; Spinella, F; Spiropulu, M; Squillacioti, P; Stadie, H; Stelzer, B; Stelzer-Chilton, O; Strologas, J; Stuart, D; Sukhanov, A; Sumorok, K; Sun, H; Suzuki, T; Taffard, A; Tafirout, R; Takach, S F; Takano, H; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tanimoto, N; Tapprogge, S; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Tether, S; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tollefson, K; Tomura, T; Tonelli, D; Tönnesmann, M; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tseng, J; Tsuchiya, R; Tsuno, S; Tsybychev, D; Turini, N; Turner, M; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vacavant, L; Vaiciulis, A; Varganov, A; Vataga, E; Vejcik, S; Velev, G; Veszpremi, V; Veramendi, G; Vickey, T; Vidal, R; Vila, I; Vilar, R; Vollrath, I; Volobouev, I; von der Mey, M; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wallny, R; Walter, T; Yamashita, T; Yamamoto, K; Wan, Z; Wang, M J; Wang, S M; Warburton, A; Ward, B; Waschke, S; Waters, D; Watts, T; Weber, M; Wester, W C; Whitehouse, B; Wicklund, A B; Wicklund, E; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wolter, M; Worcester, M; Worm, S; Wright, T; Wu, X; Würthwein, F; Wyatt, A; Yagil, A; Yang, C; Yang, U K; Yao, W; Yeh, G P; Yi, K; Yoh, J; Yoon, P; Yorita, K; Yoshida, T; Yu, I; Yu, S; Yu, Z; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zetti, F; Zhou, J; Zsenei, A; Zucchelli, S

2005-06-03

We present a measurement of the W(+)W(-) production cross section using 184 pb(-1) of p(p) collisions at a center-of-mass energy of 1.96 TeV collected with the Collider Detector at Fermilab. Using the dilepton decay channel W(+)W(-)-->l(+)nul(-), where the charged leptons can be either electrons or muons, we find 17 candidate events compared to an expected background of 5.0(+2.2)(-0.8) events. The resulting W(+)W(-) production cross-section measurement of sigma(pp-->W(+)W(-))=14.6(+5.8)(-5.1)(stat)(+1.8)(-3.0)(syst) +/- 0.9(lum) pb agrees well with the standard model expectation.

Electrochemical formation of green rusts in deaerated seawater-like solutions

Energy Technology Data Exchange (ETDEWEB)

Refait, Ph., E-mail: prefait@univ-lr.fr [Laboratoire d' etude des materiaux en milieux agressifs (LEMMA), EA 3167, Universite de La Rochelle, Bat. Marie Curie, Av. Michel Crepeau, F-17 042 La Rochelle Cedex 01 (France); Fed. de Recherche en Environnement et Developpement Durable, FR CNRS 3097 (France); Nguyen, D.D. [Laboratoire d' etude des materiaux en milieux agressifs (LEMMA), EA 3167, Universite de La Rochelle, Bat. Marie Curie, Av. Michel Crepeau, F-17 042 La Rochelle Cedex 01 (France); Hue University' s College of Education, Hue (Viet Nam); Jeannin, M. [Laboratoire d' etude des materiaux en milieux agressifs (LEMMA), EA 3167, Universite de La Rochelle, Bat. Marie Curie, Av. Michel Crepeau, F-17 042 La Rochelle Cedex 01 (France); Fed. de Recherche en Environnement et Developpement Durable, FR CNRS 3097 (France); Sable, S. [Littoral, Environnement et Societe (LiENSs), UMR 6250, CNRS-Univ. La Rochelle, Bat. Marie Curie, Av. Michel Crepeau, F-17 042 La Rochelle Cedex 01 (France); Fed. de Recherche en Environnement et Developpement Durable, FR CNRS 3097 (France); Langumier, M. [Laboratoire d' etude des materiaux en milieux agressifs (LEMMA), EA 3167, Universite de La Rochelle, Bat. Marie Curie, Av. Michel Crepeau, F-17 042 La Rochelle Cedex 01 (France); Littoral, Environnement et Societe (LiENSs), UMR 6250, CNRS-Univ. La Rochelle, Bat. Marie Curie, Av. Michel Crepeau, F-17 042 La Rochelle Cedex 01 (France); Fed. de Recherche en Environnement et Developpement Durable, FR CNRS 3097 (France); Sabot, R. [Laboratoire d' etude des materiaux en milieux agressifs (LEMMA), EA 3167, Universite de La Rochelle, Bat. Marie Curie, Av. Michel Crepeau, F-17 042 La Rochelle Cedex 01 (France); Fed. de Recherche en Environnement et Developpement Durable, FR CNRS 3097 (France)

2011-07-15

Highlights: > Sulphated green rust could be electro-generated on carbon steel in anoxic seawater-like electrolytes. > Rust layers grown during 11 years on carbon steel in natural seawater were thoroughly characterised by {mu}-Raman spectroscopy. > The mechanism of marine corrosion of carbon steel in anoxic conditions could be specified. - Abstract: Carbon steel electrodes were polarised at a potential {approx}150 mV higher than the open circuit potential, in a deaerated seawater-like electrolyte (0.5 mol dm{sup -3} NaCl, 0.03 mol dm{sup -3} Na{sub 2}SO{sub 4}, 0.003 mol dm{sup -3} NaHCO{sub 3}). X-ray diffraction and {mu}-Raman analysis demonstrated that a layer mainly composed of GR(SO{sub 4}{sup 2-}) had grown on the steel surface. GR(SO{sub 4}{sup 2-}) was accompanied by traces of GR(CO{sub 3}{sup 2-}). Similar experiments performed in a solution composed of 0.3 mol dm{sup -3} of Na{sub 2}SO{sub 4} and 0.03 mol dm{sup -3} of NaHCO{sub 3} led to the same result. The nature of the GR forming on steel is thus mainly linked to the sulphate to carbonate concentration ratio. Finally, carbon steel coupons immersed for 11 years in the harbour of La Rochelle (Atlantic coast) were removed from seawater for analysis. The inner part of the rust layer proved to be mainly composed of magnetite, GR(SO{sub 4}{sup 2-}) and iron sulphide FeS. This definitively confirms that GR(SO{sub 4}{sup 2-}), as Fe{sub 3}O{sub 4} and FeS, can form from steel in O{sub 2}-depleted environments.

White pines, Ribes, and blister rust: a review and synthesis

Science.gov (United States)

Brian W. Geils; Kim E. Hummer; Richard S. Hunt

2010-01-01

For over a century, white pine blister rust (Cronartium ribicola) has linked white pines (Strobus) with currants and gooseberries (Ribes) in a complex and serious disease epidemic in Asia, Europe, and North America. Because of ongoing changes in climate, societal demands for forests and their amenities, and scientific advances in genetics and proteomics, our current...

Physical water treatment against calcification and rust

International Nuclear Information System (INIS)

Burger, A.

1995-01-01

In contrast to Germany, where the installation of small-sized, decentralised plants is still prefered, water supply companies in countries such as Denmark have already for some time successfully been using physical water treatment systems. Although the health and environmental benefits of this non-chemical method of water treatment are undisputed and its proper application is also economically beneficial, there is still a widerspread lack of information as to where such plants can be used. Consequently, older methods are often resorted to combatting calcification and rust. (orig.) [de

On the Rust Products Formed on Weathering and Carbon Steels Exposed to Chloride in Dry-Wet Cyclical Processes

International Nuclear Information System (INIS)

Garcia, K. E.; Morales, A. L.; Barrero, C. A.; Greneche, J. M.

2005-01-01

The rust products formed on weathering and carbon steels exposed to dry-wet cyclical processes in different chloride-rich solutions are carefully examined by means of different techniques. Special emphasis is given to the methodology of analysis of the data using 300 K and 77 K Moessbauer spectrometry and X-ray diffraction. The rust that is loosely bound to the metal surface and that it is lost during the corrosion process, for both types of steel, was found to be composed of lepidocrocite, superparamagnetic goethite, hematite, and traces of akaganeite. On the other hand, the adherent rust, which is differentiated as scraped and hit according to the way it is obtained, from both steels was found to be composed of akaganeite, spinel phase, goethite exhibiting broad distribution of particle sizes and lepidocrocite. The relative abundances of rust components for both steels were very similar, suggesting similar corrosion processes. Mass loss measurements show that the corrosion rates increases with increasing the chloride concentration. The presence of large quantities of spinel phase and akaganeite are a consequence of a corrosion process under the influence of very high chloride concentrations. Our results are useful for assessing the behavior of weathering steels where the levels of chlorides are high or in contact with sea water.

Sequencing Ug99 and Other Stem Rust Races: Progress and Results

Science.gov (United States)

Over the last decade a number of different molecular methods have been used to characterize genetic diversity in Puccinia graminis. Multilocus DNA fingerprinting methods (AFLPs, RAPDs, SAMs and S-SAPs) have proven to be useful, but limited to phenotypic analysis due to the dikaryotic nature of rust ...

Sustracted library obtained from mutant sugarcane variety B 4362 resistant to rust

Directory of Open Access Journals (Sweden)

María I. Oloriz

2002-07-01

Full Text Available The hypersensitive response is one of the most powerful mechanisms for which the plants resist pathogen attack. Mutations carried out previously on the variety B4362, of sugarcane, originated five mutants that express this mechanism towards the attack of rust (Puccinia melanocephala Syd.. By means of a subtractive hybridization among the cDNA obtained starting from the resistant clone inoculated with rust and a pool of cDNA of the susceptible variety (B4362 inoculated and of the resistant clone not inoculated, it was possible to reduce the number of genes expressed during the infection with the fungus. A subtractive library was carried out where we hope that most of the genes are involved in the hypersensitive response that present these mutants towards the infection of the pathogen. Key words: Subtractive hybridization, hypersensitive response, Puccinia melanocephala Syd.

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

Uncovering leaf rust responsive miRNAs in wheat (Triticum aestivum L.) using high-throughput sequencing and prediction of their targets through degradome analysis.

Science.gov (United States)

Kumar, Dhananjay; Dutta, Summi; Singh, Dharmendra; Prabhu, Kumble Vinod; Kumar, Manish; Mukhopadhyay, Kunal

2017-01-01

Deep sequencing identified 497 conserved and 559 novel miRNAs in wheat, while degradome analysis revealed 701 targets genes. QRT-PCR demonstrated differential expression of miRNAs during stages of leaf rust progression. Bread wheat (Triticum aestivum L.) is an important cereal food crop feeding 30 % of the world population. Major threat to wheat production is the rust epidemics. This study was targeted towards identification and functional characterizations of micro(mi)RNAs and their target genes in wheat in response to leaf rust ingression. High-throughput sequencing was used for transcriptome-wide identification of miRNAs and their expression profiling in retort to leaf rust using mock and pathogen-inoculated resistant and susceptible near-isogenic wheat plants. A total of 1056 mature miRNAs were identified, of which 497 miRNAs were conserved and 559 miRNAs were novel. The pathogen-inoculated resistant plants manifested more miRNAs compared with the pathogen infected susceptible plants. The miRNA counts increased in susceptible isoline due to leaf rust, conversely, the counts decreased in the resistant isoline in response to pathogenesis illustrating precise spatial tuning of miRNAs during compatible and incompatible interaction. Stem-loop quantitative real-time PCR was used to profile 10 highly differentially expressed miRNAs obtained from high-throughput sequencing data. The spatio-temporal profiling validated the differential expression of miRNAs between the isolines as well as in retort to pathogen infection. Degradome analysis provided 701 predicted target genes associated with defense response, signal transduction, development, metabolism, and transcriptional regulation. The obtained results indicate that wheat isolines employ diverse arrays of miRNAs that modulate their target genes during compatible and incompatible interaction. Our findings contribute to increase knowledge on roles of microRNA in wheat-leaf rust interactions and could help in rust

Protein Profiling Reveals Novel Proteins in Pollen and Pistil of W22 (ga1; Ga1 in Maize

Directory of Open Access Journals (Sweden)

Jin Yu

2014-05-01

Full Text Available Gametophytic factors mediate pollen-pistil interactions in maize (Zea mays L. and play active roles in limiting gene flow among maize populations and between maize and teosinte. This study was carried out to identify proteins and investigate the mechanism of gametophytic factors using protein analysis. W22 (ga1; which did not carry a gametophytic factor and W22 (Ga1, a near iso-genic line, were used for the proteome investigation. SDS-PAGE was executed to investigate proteins in the pollen and pistil of W22 (ga1 and W22 (Ga1. A total of 44 differentially expressed proteins were identified in the pollen and pistil on SDS-PAGE using LTQ-FTICR MS. Among the 44 proteins, a total of 24 proteins were identified in the pollen of W22 (ga1 and W22 (Ga1 whereas 20 differentially expressed proteins were identified from the pistil of W22 (ga1 and W22 (Ga1. However, in pollen, 2 proteins were identified only in the W22 (ga1 and 12 proteins only in the W22 (Ga1 whereas 10 proteins were confirmed from the both of W22 (ga1 and W22 (Ga1. In contrary, 10 proteins were appeared only in the pistil of W22 (ga1 and 7 proteins from W22 (Ga1 while 3 proteins confirmed in the both of W22 (ga1 and W22 (Ga1. Moreover, the identified proteins were generally involved in hydrolase activity, nucleic acid binding and nucleotide binding. These results help to reveal the mechanism of gametophytic factors and provide a valuable clue for the pollen and pistil research in maize.

Blister rust control in the management of western white pine

Science.gov (United States)

Kenneth P. Davis; Virgil D. Moss

1940-01-01

The forest industry of the western white pine region depends on the production of white pine as a major species on about 2,670,000 acres of commercial forest land. Continued production of this species and maintenance of the forest industry at anything approaching its present level is impossible unless the white pine blister rust is controlled. Existing merchantable...

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...

Cladosporium cladosporioides and Cladosporium pseudocladosporioides as potential new fungal antagonists of Puccinia horiana Henn., the causal agent of chrysanthemum white rust.

Directory of Open Access Journals (Sweden)

David Eduardo Torres

Full Text Available Puccinia horiana Hennings, the causal agent of chrysanthemum white rust, is a worldwide quarantine organism and one of the most important fungal pathogens of Chrysanthemum × morifolium cultivars, which are used for cut flowers and as potted plants in commercial production regions of the world. It was previously reported to be controlled by Lecanicillium lecanii, Cladosporium sphaerospermum, C. uredinicola and Aphanocladium album, due to their antagonistic and hyperparasitic effects. We report novel antagonist species on Puccinia horiana. Fungi isolated from rust pustules in a commercial greenhouse from Villa Guerrero, México, were identified as Cladosporium cladosporioides and Cladosporium pseudocladosporioides based upon molecular analysis and morphological characters. The antagonism of C. cladosporioides and C. pseudocladosporioides on chrysanthemum white rust was studied using light and electron microscopy in vitro at the host/parasite interface. Cladosporium cladosporioides and C. pseudocladosporioides grew towards the white rust teliospores and colonized the sporogenous cells, but no direct penetration of teliospores was observed; however, the structure and cytoplasm of teliospores were altered. The two Cladosporium spp. were able to grow on media containing laminarin, but not when chitin was used as the sole carbon source; these results suggest that they are able to produce glucanases. Results from the study indicate that both Cladosporium species had potential as biological control agents of chrysanthemum white rust.

Glycine buffered synthesis of layered iron(II)-iron(III) hydroxides (green rusts)

DEFF Research Database (Denmark)

Yin, Weizhao; Huang, Lizhi; Pedersen, Emil Bjerglund

2017-01-01

Layered Fe(II)-Fe(III) hydroxides (green rusts, GRs) are efficient reducing agents against oxidizing contaminants such as chromate, nitrate, selenite, and nitroaromatic compounds and chlorinated solvents. In this study, we adopted a buffered precipitation approach where glycine (GLY) was used...

Genetics and mapping of a new leaf rust resistance gene in Triticum ...

Indian Academy of Sciences (India)

AMIT KUMAR SINGH

seedling stage revealed that leaf rust resistance in Selection G12 is conditioned by a single ... closely or distantly related species of wheat (McIntosh et al. 2013 ... An effort was also made to determine the chromo- ... Materials and methods.

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...

Expression of a synthetic rust fungal virus cDNA in yeast

Science.gov (United States)

Mycoviruses are viruses that infect fungi. Recently, mycovirus-like RNAs were sequenced from the fungus Phakopsora pachyrhizi, the causal agent of soybean rust. One of the RNAs appeared to represent a novel mycovirus and was designated Phakopsora pachyrhizi virus 2383 (PpV2383). The genome of PpV...

Host-induced silencing of essential genes in Puccinia triticina through transgenic expression of RNAi sequences reduces severity of leaf rust infection in wheat.

Science.gov (United States)

Panwar, Vinay; Jordan, Mark; McCallum, Brent; Bakkeren, Guus

2018-05-01

Leaf rust, caused by the pathogenic fungus Puccinia triticina (Pt), is one of the most serious biotic threats to sustainable wheat production worldwide. This obligate biotrophic pathogen is prevalent worldwide and is known for rapid adaptive evolution to overcome resistant wheat varieties. Novel disease control approaches are therefore required to minimize the yield losses caused by Pt. Having shown previously the potential of host-delivered RNA interference (HD-RNAi) in functional screening of Pt genes involved in pathogenesis, we here evaluated the use of this technology in transgenic wheat plants as a method to achieve protection against wheat leaf rust (WLR) infection. Stable expression of hairpin RNAi constructs with sequence homology to Pt MAP-kinase (PtMAPK1) or a cyclophilin (PtCYC1) encoding gene in susceptible wheat plants showed efficient silencing of the corresponding genes in the interacting fungus resulting in disease resistance throughout the T 2 generation. Inhibition of Pt proliferation in transgenic lines by in planta-induced RNAi was associated with significant reduction in target fungal transcript abundance and reduced fungal biomass accumulation in highly resistant plants. Disease protection was correlated with the presence of siRNA molecules specific to targeted fungal genes in the transgenic lines harbouring the complementary HD-RNAi construct. This work demonstrates that generating transgenic wheat plants expressing RNAi-inducing transgenes to silence essential genes in rust fungi can provide effective disease resistance, thus opening an alternative way for developing rust-resistant crops. © 2017 Her Majesty the Queen in Right of Canada. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Sensitivity of Phakopsora pachyrhizi (soybean rust) isolates to fungicides and the reduction of fungal sporulation based on fungicide and timing of application

Science.gov (United States)

Soybean rust is a damaging foliar fungal disease of soybean in many soybean-growing areas throughout the world. Strategies to manage soybean rust include the use of foliar fungicides. Fungicides types, the rate of product application, and the number and timing of applications are critical components...

Major transcriptome reprogramming underlies floral mimicry induced by the rust fungus Puccinia monoica in Boechera stricta.

Directory of Open Access Journals (Sweden)

Liliana M Cano

Full Text Available Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P. monoica-induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments and terpenoid biosynthesis (major floral volatile compounds were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry.

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.

Combinations of fungicide and cultural practices influence the incidence and impact of fusiform rust in slash pine plantations

Science.gov (United States)

James D. Haywood; Allan E. Tiarks

1994-01-01

Slash pine was grown in central Louisiana under four levels of culture with or without repeated sprayings of the systematic fungicide triadimefon for protection against fusiform rust. The eight treatment combinations were: (1)no fungicide, weed control, or fertilizer; (2)weeded; (3)weeded, applied inorganic fertilizer, and bedded before planting; (4)weeded, bedded,...

Identification and mapping of Sr46 from Aegilops tauschii accession CIae 25 conferring resistance to race TTKSK (Ug99) of wheat stem rust pathogen.

Science.gov (United States)

Yu, Guotai; Zhang, Qijun; Friesen, Timothy L; Rouse, Matthew N; Jin, Yue; Zhong, Shaobin; Rasmussen, Jack B; Lagudah, Evans S; Xu, Steven S

2015-03-01

Mapping studies confirm that resistance to Ug99 race of stem rust pathogen in Aegilops tauschii accession Clae 25 is conditioned by Sr46 and markers linked to the gene were developed for marker-assisted selection. The race TTKSK (Ug99) of Puccinia graminis f. sp. tritici, the causal pathogen for wheat stem rust, is considered as a major threat to global wheat production. To address this threat, researchers across the world have been devoted to identifying TTKSK-resistant genes. Here, we report the identification and mapping of a stem rust resistance gene in Aegilops tauschii accession CIae 25 that confers resistance to TTKSK and the development of molecular markers for the gene. An F2 population of 710 plants from an Ae. tauschii cross CIae 25 × AL8/78 were first evaluated against race TPMKC. A set of 14 resistant and 116 susceptible F2:3 families from the F2 plants were then evaluated for their reactions to TTKSK. Based on the tests, 179 homozygous susceptible F2 plants were selected as the mapping population to identify the simple sequence repeat (SSR) and sequence tagged site (STS) markers linked to the gene by bulk segregant analysis. A dominant stem rust resistance gene was identified and mapped with 16 SSR and five new STS markers to the deletion bin 2DS5-0.47-1.00 of chromosome arm 2DS in which Sr46 was located. Molecular marker and stem rust tests on CIae 25 and two Ae. tauschii accessions carrying Sr46 confirmed that the gene in CIae 25 is Sr46. This study also demonstrated that Sr46 is temperature-sensitive being less effective at low temperatures. The marker validation indicated that two closely linked markers Xgwm210 and Xwmc111 can be used for marker-assisted selection of Sr46 in wheat breeding programs.

Induced mutations for horizontal resistance. A model study using leaf rust resistance in wheat

International Nuclear Information System (INIS)

Chopra, V.L.; Sawhney, R.N.; Kumar, R.

1983-01-01

A mutant with seemingly non-specific resistance to leaf rust was obtained some time ago from the wheat variety Kharchia Local treated with NMH. This mutant is being studied genetically and in its disease reaction by laboratories in Australia, Canada and India in co-operation. The mutant showed a dominant inheritance of resistance in F 1 , but different segregation in F 2 and F 3 . This peculiar genetic behaviour has so far not been explained. (author)

Main: 1W0I [RPSD[Archive

Lifescience Database Archive (English)

Full Text Available Synonym: 3-Ketoacyl-Acyl Carrier Protein Synthase, Mitochondrial Beta-Ketoacyl-Acyl Carrier Protein Synthase; Chai...VIVLEEYEHAKRRGAKIYAELCGYGMSGDAHHITQPPEDGKGAVLAMTRALRQSGLCPNQIDYVNAHATSTPIGDAVEARAI...KTVFSEHATSGTLAFSSTKGATGHLLGAAGAVEAIFSILAIHHGVAPMTLNVKNPDPIFDKRFMPLTTSKKMLVRTAMSNSFGFGGTNASLLFASI arabi_1W0I.jpg ...

Genetic Diversity and Association of EST-SSR and SCoT Markers with Rust Traits in Orchardgrass (Dactylis glomerata L.).

Science.gov (United States)

Yan, Haidong; Zhang, Yu; Zeng, Bing; Yin, Guohua; Zhang, Xinquan; Ji, Yang; Huang, Linkai; Jiang, Xiaomei; Liu, Xinchun; Peng, Yan; Ma, Xiao; Yan, Yanhong

2016-01-08

Orchardgrass (Dactylis glomerata L.), is a well-known perennial forage species; however, rust diseases have caused a noticeable reduction in the quality and production of orchardgrass. In this study, genetic diversity was assessed and the marker-trait associations for rust were examined using 18 EST-SSR and 21 SCoT markers in 75 orchardgrass accessions. A high level of genetic diversity was detected in orchardgrass with an average genetic diversity index of 0.369. For the EST-SSR and SCoT markers, 164 and 289 total bands were obtained, of which 148 (90.24%) and 272 (94.12%) were polymorphic, respectively. Results from an AMOVA analysis showed that more genetic variance existed within populations (87.57%) than among populations (12.43%). Using a parameter marker index, the efficiencies of the EST-SSR and SCoT markers were compared to show that SCoTs have higher marker efficiency (8.07) than EST-SSRs (4.82). The results of a UPGMA cluster analysis and a STRUCTURE analysis were both correlated with the geographic distribution of the orchardgrass accessions. Linkage disequilibrium analysis revealed an average r² of 0.1627 across all band pairs, indicating a high extent of linkage disequilibrium in the material. An association analysis between the rust trait and 410 bands from the EST-SSR and SCoT markers using TASSEL software revealed 20 band panels were associated with the rust trait in both 2011 and 2012. The 20 bands obtained from association analysis could be used in breeding programs for lineage selection to prevent great losses of orchardgrass caused by rust, and provide valuable information for further association mapping using this collection of orchardgrass.

HOW TO Identify White Pine Blister Rust and Remove Cankers

Science.gov (United States)

Thomas H. Nicholls; Robert L. Anderson

1977-01-01

White pine blister rust (caused by the fungus Cronartium ribicola J. C. Fisch. ex Rabenh.) was introduced into the United States about 1900 and has since spread throughout the range of white pine. The disease intensity varies throughout the range but is normally most severe where late summers (July-September) are cool (below 67? F) and damp, conditions necessary for...

On mono-W signatures in spin-1 simplified models

International Nuclear Information System (INIS)

Haisch, Ulrich; Tait, Tim M.P.

2016-03-01

The potential sensitivity to isospin-breaking effects makes LHC searches for mono-W signatures promising probes of the coupling structure between the Standard Model and dark matter. It has been shown, however, that the strong sensitivity of the mono-W channel to the relative magnitude and sign of the up-type and down-type quark couplings to dark matter is an artefact of unitarity violation. We provide three different solutions to this mono-W problem in the context of spin-1 simplified models and briefly discuss the impact that our findings have on the prospects of mono-W searches at future LHC runs.

Genome-Wide Association Study for Identification and Validation of Novel SNP Markers for Sr6 Stem Rust Resistance Gene in Bread Wheat.

Science.gov (United States)

Mourad, Amira M I; Sallam, Ahmed; Belamkar, Vikas; Wegulo, Stephen; Bowden, Robert; Jin, Yue; Mahdy, Ezzat; Bakheit, Bahy; El-Wafaa, Atif A; Poland, Jesse; Baenziger, Peter S

2018-01-01

Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat ( Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of stem rust resistance in Nebraska winter wheat, we applied genome-wide association study (GWAS) on a set of 270 winter wheat genotypes (A-set). Genotyping was carried out using genotyping-by-sequencing and ∼35,000 high-quality SNPs were identified. The tested genotypes were evaluated for their resistance to the common stem rust race in Nebraska (QFCSC) in two replications. Marker-trait association identified 32 SNP markers, which were significantly (Bonferroni corrected P < 0.05) associated with the resistance on chromosome 2D. The chromosomal location of the significant SNPs (chromosome 2D) matched the location of Sr6 gene which was expected in these genotypes based on pedigree information. A highly significant linkage disequilibrium (LD, r 2 ) was found between the significant SNPs and the specific SSR marker for the Sr6 gene ( Xcfd43 ). This suggests the significant SNP markers are tagging Sr6 gene. Out of the 32 significant SNPs, eight SNPs were in six genes that are annotated as being linked to disease resistance in the IWGSC RefSeq v1.0. The 32 significant SNP markers were located in nine haplotype blocks. All the 32 significant SNPs were validated in a set of 60 different genotypes (V-set) using single marker analysis. SNP markers identified in this study can be used in marker-assisted selection, genomic selection, and to develop KASP (Kompetitive Allele Specific PCR) marker for the Sr6 gene. Novel SNPs for Sr6 gene, an important stem rust resistant gene, were identified and validated in this study. These SNPs can be used to improve stem rust resistance in wheat.

A X-ray diffraction analysis on constituent distribution of heavy rust layer formed on weathering steel using synchrotron radiation

International Nuclear Information System (INIS)

Hara, Shuichi

2008-01-01

A local structural analysis of heavy rust layers with large swelling and laminated layers formed on weathering steel bridges using synchrotron radiation X-ray diffraction (SR-XRD) in SPring-8 have been performed. The main constituent in average composition of the whole layer was spinel-type iron oxide [mainly Magnetite (Fe 3 O 4 )] and the mass ratio was 30-40 mass%. In contrast the mass ratio of spinel in its local parts, i.e., outer layer, inter-layer and inner layer position was not higher in common but the mass ratio of β-FeOOH was higher. Therefore it indicates that these heavy rust layers have been composed of many layers of spinel poor, rich and poor - cell (SPRaP-cell). Thus SR-XRD is useful for the analysis of the constituent distribution in the rust layer. (author)

Paradoxes in Policy Practice: Signaling Postsecondary Pathways in the Rust Belt

Science.gov (United States)

Mitra, Dana; Halabi, Saamira

2012-01-01

Context: Research increasingly suggests that the high school diploma has lost its meaning as a symbol of life preparation. Having faced economic struggles earlier and longer than most regions of the United States, the "Rust Belt" region offers important lessons for the broader nation regarding how high schools might prepare youth for…

Metal working oils. Cutting oils, rolling oils, quenching oils, rust preventive oils; Kinzoku kakoyu. Sessakuyu, atsuenyu, yakiireyu, boseiyu

Energy Technology Data Exchange (ETDEWEB)

Koyama, S. [Idemitsu Kosan Co. Ltd., Tokyo (Japan)

1996-04-01

With the demand against complicating working techniques for a background, foundations of the consideration for each of the lubricants in future are outlined. 1. Cutting oils: From the standpoint of speeding up and fireproofing, share of water-soluble type has come up to 30-40%. In this type, emulsifying dispersants and preservatives are combined. 2. Rolling oils: According to thinning of the standard thickness of steel plates, pressure of contacting surfaces has come up to 300 kg/mm{sup 2}(max.) and slip speed has increased too. In stainless steel plates, in order to get rid of the heat-streak (baking streak originated from wearing-out of oil film) shifting from neat oil to emulsion type is required. 3. Quenching oils: Following two systems are recent tendencies, the mineral oil system having excellent thermostability or the water system containing polyalkylneglycol etc., but the latter is expected from the viewpoint of fireproofing. 4. Rust preventive oils: As this oils do not aim at the rust prevention for long term, degreasing property is required. 20 refs., 5 figs., 1 tab.

Evaluation of the phenotype variability and early selection to rust of the sugar cane (Puccinia melanocephala H. & P. Syd in plants generated from irradiated callus from the variaty of sugar cane ´SP 70-1284´.

Directory of Open Access Journals (Sweden)

Apolonio Valdez Balero

2004-10-01

Full Text Available It was evaluated the variability fenotípic in early phases of selection from plants regenerated of the mutagenic treatment with dose of 30 Gy of radiations Gamma (source 60Co applicated to calluses in growth of the donating ´SP 70-1284´ tolerant to the rust disease of the sugarcane Puccinia melanocephala. The main changes the plants obtained in vitro, consinted in the height, the color, habit of growth, length and width of the leaf, as well as in the affectation for the rust disease. 14.28% of the changes all fenotipic was observed in plantín, and in the shoot the plants presented 10.99% of changes all fenotipic. In the vegetative multiplication one (MV1 three possible mutants were selected with smaller affectation in front rust disease of the sugarcan, resistance character to the rust disease efficiency of the tissue culture and the mutations induction with the dose of 30 Gy were of a mutant for each 1 525 plants evaluated in early phase of selection. Key words: variation fenotipic, selection early, mutagenesis

On mono-W signatures in spin-1 simplified models

Directory of Open Access Journals (Sweden)

Ulrich Haisch

2016-09-01

Full Text Available The potential sensitivity to isospin-breaking effects makes LHC searches for mono-W signatures promising probes of the coupling structure between the Standard Model and dark matter. It has been shown, however, that the strong sensitivity of the mono-W channel to the relative magnitude and sign of the up-type and down-type quark couplings to dark matter is an artifact of unitarity violation. We provide three different solutions to this mono-W problem in the context of spin-1 simplified models and briefly discuss the impact that our findings have on the prospects of mono-W searches at future LHC runs.

Influence of silicate ions on the formation of goethite from green rust in aqueous solution

International Nuclear Information System (INIS)

Kwon, Sang-Koo; Kimijima, Ken'ichi; Kanie, Kiyoshi; Suzuki, Shigeru; Muramatsu, Atsushi; Saito, Masatoshi; Shinoda, Kozo; Waseda, Yoshio

2007-01-01

We investigated the influence of silicate ions on the formation of goethite converted from hydroxysulphate green rust, which was synthesized by neutralizing mixed solution of Fe 2 (SO 4 ) 3 and FeSO 4 with NaOH solution, by O 2 in an aqueous solution. The pH and oxidation-reduction potential of the suspension and the Fe and Si concentrations in supernatant solutions were analyzed. X-ray diffraction results for the solid particles formed during the conversion were consistent with the results of the solution analyses. The results indicated that silicate ions suppressed the conversion from green rust to α-FeOOH and distorted the linkages of FeO 6 octahedral units in the α-FeOOH structure

Genetics and mapping of a new leaf rust resistance gene in Triticum ...

Indian Academy of Sciences (India)

AMIT KUMAR SINGH

Selection G12 carries a new gene for leaf rust resistance, tentatively named as LrSelG12. [Singh A. K. ..... long arm of chromosome 3B were found to be polymor- phic between ... due to the evolution of new virulent races in India (Tomar et al.

ARSENIC INTERACTION WITH IRON (II, III) HYDROXYCARBONATE GREEN RUST: IMPLICATIONS FOR ARSENIC REMEDIATION

Science.gov (United States)