scholarly journals Genetic Behavior of Controlling Area Under Disease Progress Curve for Stripe Rust (Puccinia striiformis f. sp. tritici) in Two Wheat (Triticum aestivum) Crosses

2009 ◽  
Vol 99 (11) ◽  
pp. 1265-1272 ◽  
Author(s):  
Muhammad Irfaq ◽  
Mir Ajab ◽  
Gul Sanat Shah Khattak ◽  
Tila Mohammad ◽  
Syed Jawad Ahmad Shah
Keyword(s):  
Stripe Rust ◽  
Puccinia Striiformis ◽  
Major Gene ◽  
Epistatic Effect ◽  
Genetic Effects ◽  
Stripe Rust Resistance ◽  
Major Genes ◽  
Disease Progress Curve ◽  
Disease Progress ◽  
Progress Curve

Genetic effects on controlling resistance to stripe rust (Puccinia striiformis f. sp. tritici Eriksson)were determined in two wheat crosses, Bakhtawar-92 (B-92) × Frontana and Inqilab-91 × Fakhre Sarhad using area under the disease progress curve (AUDPC) as a measure of stripe rust resistance. The resistant and susceptible parents involved in developing genetic populations were identified by initial assessment of 45 wheat accessions for stripe rust reaction. Mixed inheritance model was applied to the data analysis of six basic populations (P1, F1, P2, B1, B2, and F2) in the crosses. The results indicated that AUDPC in cross 1 was controlled by two major genes with additive-dominance epistatic effect plus polygenes with additive-dominance-epistatic effects (model E) whereas, in the case of cross 2, it was under the control of two major genes with additive-dominance epistatic effect plus additive-dominant polygenes (model E-1). Additive effect was predominant over all other types of genetic effects, suggesting that the delay in selection for resistance until maximum favorable genes are accumulated in the individuals is desired. The tendency of backcrosses toward their respective pollen donor parents indicated the control of resistance through nuclear genes rather than the cytoplasmic factors. Occurrence of resistant as well as susceptible transgressive segregates (though very few in F2 for each cross) indicated the presence of favorable as well as some adverse genes for resistance to stripe rust in the parents. The major gene heritability was higher than that of the polygene in B1, B2, and F2 for the crosses. The major gene as well as the polygene heritability was 48.99 to 87.12% and 2.26 to 36.80% for the two crosses, respectively. The highest phenotypic variations in AUDPC (2,504.10 to 5,833.14) for segregating progenies (B1, B2, and F2) represent that the character was highly influenced by the environment. The experimental results of the two crosses indicate that resistance to stripe rust is under control of two major genes in association with several polygene rather than cytoplasmic inheritance.

Rapid identification of a stripe rust resistance gene YrXK in Chinese wheat line Xike01015 using specific locus amplified fragment (SLAF) sequencing

Plant Disease ◽  
2021 ◽  
Author(s):  
Cai Sun ◽  
Yike Liu ◽  
Qiang Li ◽  
Baotong Wang ◽  
Shuhui Chen ◽  
...  
Keyword(s):  
Stripe Rust ◽  
Puccinia Striiformis ◽  
Gene Annotation ◽  
Dominant Gene ◽  
Rapid Identification ◽  
Wheat Breeding ◽  
Stripe Rust Resistance ◽  
Phenotypic Variance ◽  
F2 Population ◽  
Chinese Wheat

Wheat stripe rust, an airborne fungal disease and caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is one of the most devastating diseases on wheat. It is the most effective and economical measure for the diseases control to identify high-level resistance genes and apply in wheat breeding. Chinese wheat cultivar Xike01015 presents high levels of all stage resistance (ASR) to the current predominant Pst race CYR33. In this study, a single dominant gene, designated as YrXk, was identified in Xike01015 conferring resistance to CYR33 with genetic analysis of F2 and BC1 population from cross of Mingxian169 (susceptible) and Xike01015. The specific length amplified fragment sequencing (SLAF-seq) strategy was used to construct linkage map in the F2 population. QTL analysis mapped YrXk to a 12.4 Mb segment on chromosome1BS, explaining over 86.96% phenotypic variance. Gene annotation in the QTL region identified three differential expressed candidate genes , TraesCS1B02G168600.1, TraesCS1B02G170200.1, and TraesCS1B02G172400.1. The qRT-PCR results displayed that TraesCS1B02G170200.1 and TraesCS1B02G168600.1 significantly up-regulated and down-regulated, respectively, and TraesCS1B02G170200.1 slightly up-regulated after changed with CYR33 in the seedling stage, which indicating these genes may function in wheat resistance to stripe rust. The results of this study can be used in wheat breeding for improving resistance to stripe rust.

Distribution of Puccinia striiformis f. sp. tritici races and virulence in wheat growing regions of Kenya from 1970 TO 2014

Plant Disease ◽  
2021 ◽  
Author(s):  
Mercy Wamalwa ◽  
Ruth Wanyera ◽  
Julian Rodriguez-Algaba ◽  
Lesley Boyd ◽  
James Owuoche ◽  
...  
Keyword(s):  
Stripe Rust ◽  
Fungal Pathogen ◽  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Stripe Rust Resistance ◽  
Scar Markers ◽  
Seedling Resistance ◽  
Sequence Characterized Amplified Region ◽  
Triticum Spp ◽  
Virulence Diversity

Stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst), is a major threat to wheat (Triticum spp.) production worldwide. The objective of this study was to determine the virulence of Pst races prevalent in the main wheat growing regions of Kenya, which includes Mt. Kenya, Eastern Kenya, and the Rift Valley (Central, Southern, and Northern Rift). Fifty Pst isolates collected from 1970 to 1992 and from 2009 to 2014 were virulence phenotyped using stripe rust differential sets, and 45 isolates were genotyped with sequence characterized amplified region (SCAR) markers to differentiate among the isolates and identify aggressive strains PstS1 and PstS2. Virulence corresponding to stripe rust resistance genes Yr1, Yr2, Yr3, Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, Yr27 and the seedling resistance in genotype Avocet S were detected. Ten races were detected in the Pst samples obtained from 1970 to 1992, and three additional races were detected from 2009 to 2014, with a single race being detected in both periods. The SCAR markers detected both Pst1 and Pst2 strains in the collection. Increasing Pst virulence was found in the Kenyan Pst population, and that diverse Pst race groups dominated different wheat growing regions. Moreover, recent Pst races in east Africa indicated possible migration of some race groups into Kenya from other regions. This study is important in understanding Pst evolution and virulence diversity and useful in breeding wheat cultivars with effective resistance to stripe rust. Keywords: pathogenicity, Puccinia f. sp. tritici stripe (yellow) rust, Triticum aestivum

scholarly journals Management of Daylily Rust With Different Fungicides and Fungicide Combinations

2017 ◽  
Vol 18 (3) ◽  
pp. 162-165 ◽  
Author(s):  
Robert S. Emmitt ◽  
James W. Buck
Keyword(s):  
United States ◽  
Disease Management ◽  
Disease Severity ◽  
Low Cost ◽  
Single Application ◽  
Southeast United States ◽  
Disease Progress Curve ◽  
Disease Progress ◽  
Progress Curve ◽  
Disease Pressure

Production nurseries and daylily hybridizers in the southeast United States rely on the use of fungicides to manage daylily rust, caused by the fungus Puccinia hemerocallidis. Foliar sprays of pyraclostrobin, flutolanil, tebuconazole, myclobutanil, chlorothalonil, mancozeb, pyraclostrobin + boscalid, flutolanil + tebuconazole, flutolanil + myclobutanil, flutolanil + chlorothalonil, and flutolanil + mancozeb applied on 14-day intervals, and a nontreated control, were evaluated under high disease pressure at three locations in Griffin, GA, in 2015. Tebuconazole or the tebuconazole + flutolanil treatment consistently had the lowest area under the disease progress curve (AUDPC) of the treatments. The addition of flutolanil to chlorothalonil or mancozeb did not improve rust control and no difference in disease severity was observed in any treatment containing contact fungicides on all assessment dates. Single application costs ranged from $10.21 to $95.96 with tebuconazole providing excellent disease management at a relatively low cost per application ($13.90).

scholarly journals Temporal progress of southern rust in maize under different environmental conditions

2003 ◽  
Vol 28 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Cláudia V. Godoy ◽  
Lílian Amorim ◽  
Armando Bergamin Filho ◽  
Herbert P. Silva ◽  
Willian J. Silva ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Disease Severity ◽  
Logistic Model ◽  
Inflection Point ◽  
Gompertz Model ◽  
Disease Progress Curve ◽  
Disease Progress ◽  
Progress Curve ◽  
Puccinia Polysora ◽  
The Mean

The progress of the severity of southern rust in maize (Zea mays) caused by Puccinia polysora was quantified in staggered plantings in different geographical areas in Brazil, from October to May, over two years (1995-1996 and 1996-1997). The logistic model, fitted to the data, better described the disease progress curves than the Gompertz model. Four components of the disease progress curves (maximum disease severity; area under the disease progress curve, AUDPC; area under the disease progress curve around the inflection point, AUDPCi; and epidemic rate) were used to compare the epidemics in different areas and at different times of planting. The AUDPC, AUDPCi, and the epidemic rate were analyzed in relation to the weather (temperature, relative humidity, hours of relative humidity >90%, and rainfall) and recorded during the trials. Disease severity reached levels greater than 30% in Piracicaba and Guaíra in the plantings between December and January. Lower values of AUDPC occurred in later plantings at both locations. The epidemic rate was positively correlated (P < 0.05) with the mean daily temperatures and negatively correlated with hours of relative humidity >90%. The AUDPC was not correlated with any weather variable. The AUDPCi was negatively related to both variables connected to humidity, but not to rain. Long periods (mostly >13 h day-1) of relative humidity >90% (that corresponded to leaf wetness) occurred in Castro. Severity of southern rust in maize has always been low in Castro, thus the negative correlations between disease and the two humidity variables.

scholarly journals Fungicides for Control of Downy Mildew on Pickling Cucumber in Michigan

2019 ◽  
Vol 20 (3) ◽  
pp. 165-169 ◽  
Author(s):  
Katelyn E. Goldenhar ◽  
Mary K. Hausbeck
Keyword(s):  
Downy Mildew ◽  
Untreated Control ◽  
Field Studies ◽  
Pseudoperonospora Cubensis ◽  
Relative Area ◽  
Disease Progress Curve ◽  
Cucurbit Downy Mildew ◽  
Disease Progress ◽  
Pickling Cucumber ◽  
Progress Curve

Michigan growers rely on fungicides to limit cucurbit downy mildew (CDM), incited by Pseudoperonospora cubensis; resistance of the pathogen to fungicides is a concern. We evaluated fungicides against CDM in Michigan field studies from 2015 to 2017. According to the relative area under the disease progress curve (rAUDPC), in 2015, mandipropamid, propamocarb, fluxapyroxad/pyraclostrobin, copper octanoate, and dimethomorph resulted in disease levels similar to the control. These treatments, along with cymoxanil, were similar to the control in 2016. Fungicides that were ineffective during 2015 and 2016 did not limit CDM in 2017. Famoxadone/cymoxanil and fluopicolide did not limit CDM in 2017. Each year, the following treatments were similar for disease based on rAUDPC data: oxathiapiprolin applied alone or premixed with chlorothalonil or mandipropamid, ametoctradin/dimethomorph, fluazinam, mancozeb/zoxamide, cyazofamid, and ethaboxam. An exception occurred in 2017, when ethaboxam was less effective than fluazinam, oxathiapiprolin/chlorothalonil, and oxathiapiprolin/mandipropamid. Mancozeb and chlorothalonil treatments were similar in 2015 and 2017, according to rAUDPC data. In 2017, yields were increased for oxathiapiprolin/chlorothalonil, oxathiapiprolin/mandipropamid, mancozeb, ametoctradin/dimethomorph, mancozeb/zoxamide, ethaboxam, cyazofamid, chlorothalonil, and fluazinam compared with the untreated control.

scholarly journals Emerging Yr26-Virulent Races of Puccinia striiformis f. tritici Are Threatening Wheat Production in the Sichuan Basin, China

Plant Disease ◽  
2015 ◽  
Vol 99 (6) ◽  
pp. 754-760 ◽  
Author(s):  
D. J. Han ◽  
Q. L. Wang ◽  
X. M. Chen ◽  
Q. D. Zeng ◽  
J. H. Wu ◽  
...  
Keyword(s):  
Stripe Rust ◽  
Sichuan Basin ◽  
Puccinia Striiformis ◽  
Field Tests ◽  
Wheat Breeding ◽  
Stripe Rust Resistance ◽  
Breeding Lines ◽  
Wheat Production ◽  
Stripe Rust Resistance Gene ◽  
The Sichuan Basin

Stripe rust, caused by Puccinia striiformis f. tritici, is one of the most destructive diseases of wheat in the world. The Sichuan Basin is one of the most important regions of wheat production and stripe rust epidemics in China. Stripe rust resistance gene Yr26 (the same gene as Yr24) has been widely used in wheat breeding programs and in many cultivars grown in this region since the gene was discovered in the early 1990s. Virulence to Yr26 has increased in frequency since its first detection in 2008. The objective of this study was to assess the vulnerability of the wheat cultivars and breeding lines in the Sichuan Basin to Yr26-virulent races. In total, 85 wheat accessions were tested with Yr26-avirulent races CYR32, CYR33, and Su11-4 and two Yr26-virulent races, V26/CM42 and V26/Gui22. DNA markers for Yr26 were used to determine the presence and absence of Yr26 in the wheat accessions. Of the 85 wheat accessions, only 5 were resistant and 19 susceptible to all races tested, and the remaining 61 were resistant to at least one or more races tested in seedling stage. In all, 65 (76.5%) accessions were susceptible to the emerging Yr26-virulent race V26/Gui22. In field tests, susceptible accessions increased from 31.8% in a nursery inoculated with predominant and Yr26-avirulent races to 61.2% in the nursery inoculated with the predominant races mixed with V26/Gui22. Based on the results of the molecular marker and race tests, 33 (38.8%) accessions were determined to have Yr26, showing that the Yr26 virulence is a major threat to wheat production in the Sichuan Basin and potentially in other regions of China.

scholarly journals Stability of Slow-Rusting Resistance to Puccinia asparagi and Managing Rust in Asparagus

Plant Disease ◽  
2012 ◽  
Vol 96 (7) ◽  
pp. 997-1000 ◽  
Author(s):  
Dennis A. Johnson
Keyword(s):  
Irrigation Management ◽  
Field Trials ◽  
Disease Progress Curve ◽  
Resistant Cultivars ◽  
Disease Progress ◽  
Slow Rusting ◽  
South Central ◽  
Progress Curve ◽  
The Stability

The stability of slow-rusting resistance to Puccinia asparagi in several asparagus cultivars was evaluated in two replicated field trials. Rust epidemics were monitored in each trial for 8 years spanning a period of 13 years (1983–1990 and 1987–1995). Inoculum of P. asparagi, an autoecious macrocyclic rust, originated each year as teliospores. In the first trial, the cultivars Jersey Titan, Jersey Centennial, Jersey Giant, Delmonte-361, and UC-157 had consistently lower area under the disease progress curve (AUDPC) values than Wash T2 and WSU-1. Cultivar Mary Washington was intermediate between the two groups of resistant and susceptible cultivars in 6 of 8 years. Jersey Titan consistently ranked number 1 for resistance with the lowest AUDPC values all 8 years. In the second trial, Jersey Giant, Delmonte-361, and UC-157 had consistently lower AUDPC values than Larac, Gynlim, Cito, Largo 17-3, and Franklim in each of 8 years. Jersey Giant, Delmonte-361, and UC-157 always ranked low (1, 2, or 3) for AUDPC. A shift from rust-susceptible to rust-resistant asparagus cultivars began in central Washington around 1996. In 2011, resistant cultivars made up nearly 96% of the asparagus plantings. From 1996 to 2011, rust was not considered a problem in commercial fields with slow-rusting resistant cultivars. Use of durable, slow-rusting cultivars, along with sanitation practices that reduced levels of aecia in nonharvested nurseries and on volunteer asparagus plants and judicious irrigation management, has effectively managed asparagus rust in commercial fields for at least 29 years in south-central Washington.

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