Virulence in populations of Puccinia graminis f.sp. tritici in Canada from 1952 to 1998: a non-parametric analysis

2001 ◽  
Vol 79 (5) ◽  
pp. 556-569
Author(s):  
D E Harder ◽  
B R Baum ◽  
B D McCallum
Keyword(s):  
Parametric Analysis ◽  
Binary Data ◽  
Infection Type ◽  
Single Gene ◽  
Data Matrix ◽  
Puccinia Graminis ◽  
Heterogeneous Database ◽  
Pacific Population ◽  
The Pacific ◽  
Non Parametric

Six hundred and twenty six isolates of Puccinia graminis f.sp. tritici that were collected and stored between 1952 and 1998 were identified using 32 single-gene differential wheat lines. These pathotypes represented isolates from field surveys, nursery collections, and from greenhouse experiments. Infection type data was converted to a binary data matrix with a 0 (resistant) or 1 (susceptible) numeral assigned to each isolate for each differential line. The Gower coefficient of similarity was determined for every pair of isolates, then they were clustered using the non-parametric cluster analysis MODECLUS. Eight significantly different clusters were obtained from an overall heterogeneous database of 405 unique pathotypes representing all regions of Canada. For further analysis, isolates obtained only from field survey collections were selected and divided by region of collection into Pacific (45 pathotypes), prairie (191 pathotypes), and eastern Canadian (83 pathotypes) populations. The Pacific population, which was both sexually and asexually reproducing, consisted of two clusters. The prairie population, strictly asexually reproducing, consisted of nine clusters, and the eastern population, which may be partially sexually reproducing, had three clusters. The Pacific population was shown to be significantly different from the prairie and eastern populations, while the prairie and eastern populations were less distinct. The pathotype composition of the regional clusters, reliability of cluster segregation using non-parametric analysis, and usefulness of the data to contribute to a revised nomenclature of P. graminis f.sp. tritici, are evaluated.Key words: stem rust, black rust, wheat, specific virulence.

scholarly journals The Spread of Stem Rust Caused by Puccinia graminis f. sp. tritici, with Virulence on Sr31 in Wheat in Eastern Africa

Plant Disease ◽  
2006 ◽  
Vol 90 (1) ◽  
pp. 113-113 ◽  
Author(s):  
R. Wanyera ◽  
M. G. Kinyua ◽  
Y. Jin ◽  
R. P. Singh
Keyword(s):  
Stem Rust ◽  
Rust Resistance ◽  
Infection Type ◽  
Single Gene ◽  
Stem Rust Resistance ◽  
Eastern Africa ◽  
Puccinia Graminis ◽  
High Infection ◽  
Infection Types ◽  
Sr Genes

Stem rust resistance in wheat cultivars with Sr31 has been effective and durable worldwide for more than 30 years. Isolates of Puccinia graminis f. sp. tritici with virulence to Sr31 were detected in Uganda in 1999 (1). During 2003 and 2004, a majority of current Kenyan cultivars and a large portion of CIMMYT wheat germplasm with gene Sr31 planted in Kenya were susceptible to stem rust. Six isolates collected during 2004 at different locations in Kenya were tested for virulence on the 16 North American stem rust race differentials with the following Sr genes: Sr5, 6, 7b, 8a, 9a, 9b, 9d, 9e, 9g, 10, 11, 17, 21, 30, 36, and Tmp. An extended set of designated Sr genes (Sr13, 19, 22, 24, 25, 26, 29, 31, 32, 33, 35, 37, 39, 40, 44, and Wld-1) was also tested at the seedling stage. An isolate from Uganda collected in 1999 with virulence on Sr31 was used for comparison. Urediniospores suspended in a lightweight mineral oil were inoculated onto 7-day-old seedlings. Inoculated plants were placed in a dew chamber for 14 h at 18°C in the dark and then for an additional period of 3 to 4 h placed under fluorescent light. Plants were incubated in a greenhouse at 18 ± 2°C with a photoperiod of 16 h. Infection types (IT), described by Stakman et al. (3), were assessed after 14 days postinoculation. All isolates from Kenya exhibited a low infection type (IT 0) on line W2691SrTt-1 (donor of Sr36), a low infection type (IT 2) on cv. Triumph 64 (donor of SrTmp), and high infection types (IT 3 or 4) on all other lines in the differential set (2); thus these isolates were keyed to race TTKS. The virulence pattern of the isolate collected in 1999 from Uganda was identical to that from Kenya on the differential set and on the extended set of designated Sr genes. In this study, these isolates produced a high infection type (IT 3) on Einkorn and CnSSr21Tm (a derivative of Triticum monococcum in Chinese Spring background), two sources of Sr21 used in our study, whereas the isolate with Sr31-virulence from Uganda in 1999 was reported to be avirulent on Sr21 (1). These isolates produced high infection types on single gene lines with Sr31 and winter wheat cvs. Custer, Foster, GA-Dozier, Patton, and Pioneer 26R61, which were known to carry the 1BL.1RS translocation with Sr31. These isolates were also virulent on SrWld-1, a gene used in spring wheat for its resistance to North American stem rust isolates. In addition to Sr36 and SrTmp, other stem rust resistance genes that were effective against TTKS at the seedling stage include Sr13, 22, 24, 25, 26, 27, 29, 32, 33, 35, 37, 39, 40, and 44. Cultivars, breeding germplasm, and single gene lines are currently being evaluated for adult plant reaction in Kenya. Results from this study indicated that stem rust isolates with virulence on Sr31 are now wide spread in the Eastern Africa highlands and pose a threat to wheat production in the region, as well as in other wheat production areas where Sr31 resistance is important. A rapid deployment of effective resistance genes to this race in breeding programs throughout Eastern Africa and Asia is needed to reduce this threat. References: (1) Z. A. Pretorius et al. Plant Dis. 84:203, 2000. (2) A. P. Roelfs and J. W. Martens. Phytopathology 78:526, 1988. (3) E. C. Stakman et al. U.S. Department of Agriculture. ARS E-617, 1962.

scholarly journals First Report of Races TKTTP and TKKTP of Puccinia graminis f. sp. tritici with Virulence to Wheat Stem Rust Resistance Gene Sr24 in Turkey and Tunisia

Plant Disease ◽  
2021 ◽  
Author(s):  
Kumarse Nazari ◽  
Ezgi Kurtulus ◽  
Handan Kavaz ◽  
Omer M. Ozturk ◽  
Yesim Egerci ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Stem Rust ◽  
Rust Resistance ◽  
Infection Type ◽  
Single Gene ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Wheat Cultivars ◽  
Wheat Stem Rust ◽  
First Report

Severe wheat stem rust caused by Puccinia graminis Pers.:Pers. f. sp. tritici Erikss. (Pgt) can result in complete crop failure. In recent years, the increasing frequency and the early onset of stem rust in Central West Asia and North Africa (CWANA) has become a big concern. The Sr24 resistance gene, one of the most effective stem rust resistance genes effective against most P. graminis f. sp. tritici races worldwide, has been widely deployed. Until the recent establishment of virulence to Sr24 within the Ug99 lineage of the pathogen in Africa (Hei et al. 2020; Jin et al. 2008; Patpour et al. 2015), Iraq (Nazari et al., 2021), occasional detections of races virulent to Sr24 were reported in South Africa (Le Roux and Rijkenberg 1987), India (Bhardwaj et al. 1990), Germany (Olivera Firpo et al. 2017), Georgia (Olivera, et al. 2019), and Western Siberia (Skolotneva et al., 2020). During the rust surveys conducted in Sinops, Samsun, and Kastomonu in the Black Sea region in northern Turkey in 2018, 19 isolates were collected. Single pustule (SP) isolates were developed and used in race analysis in the Biosafety Rust Laboratory, Regional Cereal Rust Research Center (RCRRC), Izmir, Turkey. Sample recovery, experimental procedures for pre-inoculation, inoculation, incubation, and race typing were conducted as previously described (Nazari et al. 2021). Among the tested SP isolates, two isolates showed a high infection type (IT) of 33+ on the Sr24 tester line (Little Club/Agent) and a low infection type of 11+ for the source of Sr31 (Benno/6*LMPG-6). Eight SP isolates were further developed from the high IT 33+ pustules collected from the Sr24 tester line. After spore multiplications, they were used in inoculation of the 20 North American stem rust single-gene lines used to differentiate races of P. graminis f. sp. tritici, plus Trident (Sr38+), Siouxland (Sr24+Sr31), and Sisson (Sr31+Sr36). Five SP-derived isolates with IT 33+ on the Sr24 single-gene line collected from Samsun (Alacam – Etyemez; Location: N 41.61889 E 35.55722) and Sinop (Merkez-Sanlıoglu; Location: N 41.85556 E 35.04889) were identified as race TKKTP and the remaining three SP isolates as race TKTTP. In 2020, we detected two isolates of TKKTP among the stem rust samples from Tunisia submitted to RCRRC. These two isolates were collected from bread wheat cultivars Heydna and Tahmet at a trial site near Bou Salem in Western Tunisia (Location: N 36.5351 E 8.95486). Based on the negative results of the Stage 1 test using a suite of four real-time polymerase chain reaction assays diagnostic for the Ug99 race group developed by Szabo (2012), these two races should not belong to the Ug99 race group when compared to the reference Ug99 race TTKTT from Kenya. These races were virulent to Sr5, Sr21, Sr9e, Sr7b, Sr6, Sr8a, Sr9g, Sr9b, Sr30, Sr17, Sr9a, Sr9d, Sr10, SrTmp, Sr24, Sr38, and SrMcN. In addition to these genes, race TKTTP was virulent to Sr36. Both races were avirulent to Sr11 and Sr31. To our knowledge, this is the first report of P. graminis f. sp. tritici races with the Sr24 virulence in Turkey and Tunisia. The results reflect an increasing trend of virulence to Sr24 in the pathogen populations, and raise a great concern given the deployment of the Sr24 resistance gene in widely grown wheat cultivars worldwide.

Evaluating the Performance of Hedge Fund Strategies: A Non-Parametric Analysis

2015 ◽  
Author(s):  
Alessandra Canepa ◽  
Maria O. Gonzalez ◽  
Frank S. Skinner
Keyword(s):  
Parametric Analysis ◽  
Hedge Fund ◽  
Non Parametric

scholarly journals Conservation Evaluation of the Pacific Population of Dwarf Woollyheads, Psilocarphus brevissimus var. brevissimus, in Canada

2006 ◽  
Vol 120 (2) ◽  
pp. 163
Author(s):  
George W. Douglas ◽  
Jenifer L. Penny ◽  
Ksenia Barton
Keyword(s):  
British Columbia ◽  
Coalbed Methane ◽  
Groundwater Levels ◽  
Gas Drilling ◽  
Pacific Population ◽  
South Central ◽  
The Pacific ◽  
Recreational Vehicles ◽  
Forest Openings ◽  
Conservation Evaluation

In Canada, Dwarf Woolly-heads, Psilocarphus brevissimus var. brevissimus, is restricted to the Similkameen River valley, south of Princeton in southwestern British Columbia and the extreme southeast and southwest corners of Alberta and Saskatchewan, respectively. This paper deals with the three British Columbia populations which represent the northwestern limit of the species which ranges from south-central British Columbia, southward in the western United States to Montana, Idaho, Washington, Oregon, Nevada, Utah, Wyoming, California and Baja California, Mexico. In British Columbia, P. brevissimus is associated with calcareous vernal pools and ephemeral pond edges in large forest openings. This habitat is rare in the area the few existing populations could easily be extirpated or degraded through slight changes in groundwater levels, coalbed methane gas drilling, housing development or recreational vehicles.

scholarly journals Generalized Correlation Coefficient for Non-Parametric Analysis of Microarray Time-Course Data

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Qihua Tan ◽  
Mads Thomassen ◽  
Mark Burton ◽  
Kristian Fredløv Mose ◽  
Klaus Ejner Andersen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Correlation Coefficient ◽  
Parametric Analysis ◽  
Time Course ◽  
Expression Patterns ◽  
Gene Expression Patterns ◽  
Microarray Time Course ◽  
Time Course Data ◽  
Generalized Correlation ◽  
Non Parametric

AbstractModeling complex time-course patterns is a challenging issue in microarray study due to complex gene expression patterns in response to the time-course experiment. We introduce the generalized correlation coefficient and propose a combinatory approach for detecting, testing and clustering the heterogeneous time-course gene expression patterns. Application of the method identified nonlinear time-course patterns in high agreement with parametric analysis. We conclude that the non-parametric nature in the generalized correlation analysis could be an useful and efficient tool for analyzing microarray time-course data and for exploring the complex relationships in the omics data for studying their association with disease and health.

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