NEW GENES FOR RESISTANCE TO RACES OF OAT STEM RUST

1961 ◽  
Vol 39 (3) ◽  
pp. 513-518 ◽  
Author(s):  
J. N. Welsh ◽  
G. J. Green ◽  
R. I. H. McKenzie
Keyword(s):  
Stem Rust ◽  
Major Gene ◽  
Single Gene ◽  
Puccinia Graminis ◽  
Major Genes ◽  
F Gene ◽  
E Gene ◽  
New Genes ◽  
New Gene ◽  
New Races

The inheritance in oats of reaction to some new races and to some well-known races of oat stem rust, Puccinia graminis Pers. f. sp. avenae Erikss. and Henn., was investigated in the crosses Jostrain × Eagle, Canuck × Cherokee, and R.L. 524.1 (Hajira × Banner) × Eagle. The resistance of the variety Jostrain to races 1, 3, 4, 13, and 13A was conferred by a single gene, here designated as the E gene in accordance with the practice of designating genes for stem rust resistance by capital letters. Canuck, a derivative of Jostrain, carries the new E gene and the previously identified B gene. The resistance of R.L. 524.1 to all races is conferred by two major genes and a modifying gene. One of the major genes acts like the well-known B gene which confers resistance to all races except 6A, 7A, 8A, and 13A. The other major gene apparently is a new gene in oats for resistance to stem rust and is here designated the F gene. The F gene confers resistance to all races but a modifying gene is required along with it for resistance to race 7.

Inheritance of resistance to stem rust in 'Bonza', 'Chris', 'FKN-II-50-17', 'MRFY', 'Thatcher', 'Marquillo', and 'Hope' wheats

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 269-276
Author(s):  
M. Padidam ◽  
D. R. Knott
Keyword(s):  
Triticum Aestivum ◽  
Plant Resistance ◽  
Stem Rust ◽  
Adult Plant Resistance ◽  
Major Gene ◽  
Triticum Aestivum L ◽  
Adult Plant ◽  
Puccinia Graminis ◽  
Seedling Resistance ◽  
Minor Genes

Resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks, and Henn.), particularly adult plant resisitance to race 15B-1, was studied in seven wheat (Triticum aestivum L.) cultivars or lines: 'Bonza', 'Chris', 'FKN-II-50-17', 'MRFY', 'Thatcher', 'Marquillo', and 'Hope'. Each of the seven was crossed with a susceptible parent and either F4- or F5-derived lines developed by single seed descent. All of the lines were tested with race 15B-1 in field nurseries. Lines derived from parents carrying seedling resistance to race 15B-1 were also tested as seedlings in the greenhouse with race 15B-1, and in some cases races 56, 29, and C65. The data indicated that 'Bonza' carries Sr6, probably Sr5, an unidentified gene giving resistance to race 56, two unidentified genes for resistance to race C65, and two minor genes that combine to produce intermediate adult plant resistance. 'Chris' carries Sr5, Sr7a, Sr8a, and Sr12. In addition, it may have three minor genes for adult plant resistance. 'FKN-II-50-17' carries Sr6 and may have four minor genes that combine to produce moderate adult plant resistance. 'MRFY', which is seedling susceptible to race 15B-1, carries Sr9b, possibly Sr5, plus an unidentified gene for resistance to C65. In addition, it appears to have one major gene for adult plant resistance plus two or more minor genes. 'Thatcher', 'Marquillo', and 'Hope' had only limited resistance to race 15B-1 in the field and no genetic analysis of their crosses was possible. The four parents that had good resistance to race 15B-1 in the field, 'Bonza', 'Chris', 'FKN-II-50-17', and 'MRFY', all carry minor genes for adult plant resistance that had little effect individually but produced moderate resistance when combined. The genes Sr5 and Sr9b, which have no effect on resistance to 15B-1 is seedlings, were found to significantly increase resistance in adult plants in the field.Key words: stem rust, Puccinia graminis tritici, wheat, Triticum aestivum, adult plant rust resistance.

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.

THE INHERITANCE OF RUST RESISTANCE: VII. THE INHERITANCE OF RESISTANCE TO RACES 15B AND 56 OF STEM RUST IN ELEVEN COMMON WHEAT VARIETIES OF DIVERSE ORIGIN

1961 ◽  
Vol 41 (3) ◽  
pp. 587-601 ◽  
Author(s):  
D. R. Knott ◽  
I-Sun Shen
Keyword(s):  
Stem Rust ◽  
Rust Resistance ◽  
Inheritance Of Resistance ◽  
Susceptible Parent ◽  
Wheat Varieties ◽  
New Genes ◽  
New Gene ◽  
Diverse Origin ◽  
Inheritance Of Rust Resistance ◽  
Moderate Resistance

In an attempt to locate new genes for stem rust resistance, 11 varieties of wheat of as diverse origins as possible were studied. Each variety was backcrossed to the susceptible parent Marquis. The F2 families from the backcrosses were tested with races 15B and 56, and the inheritance of resistance determined. The genes carried by each variety were identified from the results of test crosses with varieties carrying known genes and with lines of Marquis carrying single genes for resistance. Most of the resistance present in the 11 varieties could be accounted for on the basis of known genes (Sr6 – Sr10). However, at least one new gene conditioning moderate resistance to race 15B, and possibly one or more new genes conditioning moderate resistance to race 56, were identified.

scholarly journals Some important factors affecting fertility in sheep

2012 ◽  
Vol 28 (3) ◽  
pp. 517-528 ◽  
Author(s):  
Milan Petrovic ◽  
V. Caro-Petrovic ◽  
D. Ruzic-Muslic ◽  
N. Maksimovic ◽  
Z. Ilic ◽  
...  
Keyword(s):  
Body Condition Score ◽  
Genetic Relationships ◽  
Major Gene ◽  
Single Gene ◽  
Phenotypic Expression ◽  
Reproductive Traits ◽  
Selection Response ◽  
Major Genes ◽  
Mating Period ◽  
Sheep Production

Efficiency of sheep production is conditioned by fertility. According to some authors number of offspring obtained per lambing is more important than gain of weight. Genetic relationships involving reproductive traits were seldom studied. Reproductive traits have low heritabilities, a discrete phenotypic expression, and are expressed only in sexually mature ewes leading to low selection intensities and long generation intervals. Documentation of realized selection response is also often complicated by the low heritabilities of fertility traits. Existence of a major gene affecting prolificacy had been suggested and at that time there were many sceptics who strongly doubted that a trait as complex as reproduction could be profoundly influenced by a single gene. Major genes affecting prolificacy in sheep was founded. A mutation in the bone morphogenetic protein 15 gene (BMP15, also known as GDF9B) responsible for high prolificacy in Inverdale sheep had been discovered and evidence of segregating major genes was being reported from flocks around the world. Development of gene mapping techniques, and locating alleles that are responsible for the fertility of sheep began a new chapter in predicting and controlling the fertility of sheep. The beneficial effects of nutrition on reproduction in sheep are well known. This procedure is known as flushing. The effect of Body Condition Score (BCS), before mating, during mating and after mating period, on reproductive efficiency of different breeds of sheep in the different rearing systems were studied. The farm manager has the ability to control or at least to manipulate the factors that have an impact on fertility.

scholarly journals Presence of a Sexual Population of Puccinia graminis f. sp. tritici in Georgia Provides a Hotspot for Genotypic and Phenotypic Diversity

2019 ◽  
Vol 109 (12) ◽  
pp. 2152-2160 ◽  
Author(s):  
Pablo D. Olivera ◽  
Zoya Sikharulidze ◽  
Rusudan Dumbadze ◽  
Les J. Szabo ◽  
Maria Newcomb ◽  
...  
Keyword(s):  
Stem Rust ◽  
Phenotypic Diversity ◽  
Genotypic Diversity ◽  
Puccinia Graminis ◽  
Alternate Host ◽  
Wheat Stem Rust ◽  
Caucasus Region ◽  
Sexual Recombination ◽  
New Races ◽  
Pathogen Populations

Wheat stem rust, caused by Puccinia graminis f. sp. tritici, is a re-emerging disease exemplified by recent epidemics caused by new virulent races. Understanding the sources and origins of genetic variations in the pathogen populations globally can facilitate the development of better strategies in disease management. We analyzed 68 wheat stem rust samples collected between 2013 and 2015 from Georgia where stem rust incidences are frequent and the alternate host, common barberry, is present. A total of 116 single-pustule isolates were derived and evaluated on stem rust differential lines to determine the virulence phenotypes and 23 races were identified, many of which were detected for the first time. Unique virulence combinations including, Sr22+Sr24 and Sr13b+Sr35+Sr37 were detected. These virulence combinations pose new challenges to breeding programs because many of these genes are used in breeding for resistance to the Ug99 race group. Sixty-one isolates were genotyped using a custom single-nucleotide polymorphism chip and 17 genotypes were identified. The 2013 isolates contained 11 multilocus genotypes compared with isolates of 2014 and 2015, with five and three genotypes, respectively. The higher levels of virulence and genotypic diversity observed in the 2013 samples strongly indicated that sexual recombination occurs in the Georgian P. graminis f. sp. tritici population, and that the Caucasus region of Eurasia may be an important source of new races. [Formula: see text] Copyright © 2019 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

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.

scholarly journals Genetics of Resistance to Race TTKSK of Puccinia graminis f. sp. tritici in Triticum monococcum

2011 ◽  
Vol 101 (12) ◽  
pp. 1418-1423 ◽  
Author(s):  
M. N. Rouse ◽  
Y. Jin
Keyword(s):  
Resistance Genes ◽  
Stem Rust ◽  
Genetic Resistance ◽  
Triticum Monococcum ◽  
Puccinia Graminis ◽  
New Genes ◽  
Resistant Varieties ◽  
A Genome ◽  
Stem Rust Resistance Genes ◽  
Virulence Spectrum

Race TTKSK (or Ug99) of Puccinia graminis f. sp. tritici possesses virulence to several stem rust resistance genes commonly present in wheat cultivars grown worldwide. New variants detected in the race TTKSK lineage further broadened the virulence spectrum. The identification of sources of genetic resistance to race TTKSK and its relatives is necessary to enable the development and deployment of resistant varieties. Accessions of Triticum monococcum, an A-genome diploid wild and cultivated wheat, have previously been characterized as resistant to stem rust. Three resistance genes were identified and introgressed into hexaploid wheat: Sr21, Sr22, and Sr35. The objective of this study was to determine the genetic control and allelic relationships of resistance to race TTKSK in T. monococcum accessions identified through evaluations at the seedling stage. Generation F2 progeny of 8 crosses between resistant and susceptible accessions and 13 crosses between resistant accessions of T. monococcum were evaluated with race TTKSK and often with North American races, including races QFCSC, TTTTF, and MCCFC. For a selected population segregating for three genes conferring resistance to race TTKSK, F2:3 progeny were evaluated with races TTKSK, QFCSC, and TTTTF. In that population, we detected two genes conferring resistance to race TTKSK that are different from Sr21, Sr22, and Sr35. One of the new genes was effective to all races tested. The identification of these genes will facilitate the development of varieties with new resistance to race TTKSK.

Production of new races of Puccinia graminis var Tritici

1969 ◽  
Vol 20 (6) ◽  
pp. 981 ◽  
Author(s):  
SK Sharma ◽  
R Prasada
Keyword(s):  
Stem Rust ◽  
Puccinia Graminis ◽  
Wheat Cultivars ◽  
Wheat Seedlings ◽  
Somatic Recombination ◽  
New Races ◽  
X 24

To study the phenon~enon of somatic recombination in stem rust of wheat, seedlings of selected wheat cultivars were inoculated with these six pairs of races: 15CM x 14, 15CM x 17, 15CM x 21, 15CM x 24, 15CM x 42, and 15CM x 117. Recombinants were isolated from only the first two mixtures. As a result of mixing races 15CM x 14, eight races and biotypes were isolated of which three were previously undescribed. From the recombinants of races 15CM x 17, six races and biotypes were identified, of which three were new and previously undescribed.

Stop the new gene, the alien: Predicted breakdown of MYB overexpression by ncRNA mediated gene regulations

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
NEHA SINGH ◽  
INDERJEET BHOGAL ◽  
ABHISHEK KUMAR ◽  
PUNIT TYAGI ◽  
GIRIJA SIKARWAR ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Gene ◽  
Neutral Theory ◽  
Poor Performance ◽  
Warning Sign ◽  
Cellular Mechanisms ◽  
Constitutive Overexpression ◽  
New Gene ◽  
Altered Gene ◽  
Growing Conditions

Acclimatization is a process that occurs in individual cells to a drastic change in micro and macro environments. When an organism is subjected to a new environment or a change in its normal growing conditions, the cellular mechanisms initiate a warning sign and over a period of time or over generations the acquired, modified traits are being communicated and fixed as a new trait. If there is lack of equilibrium within the cell due to over expression of a single gene or network of associated genes either manmade or due to mutations, the organism or plant tries to fix it by initiating gene regulatory mechanisms. According to our neutral theory of gene expression, always a cell tries to maintain its pH by modifying its cytosol through altered gene expression. In the present investigation, 198 AtMYB genes were analyzed and found to play an intrinsic photosystem linked network of 38 nodes where MYB being regulated by a set of 48 miRNAs. Members of the network have evidence-based link to energy related mechanisms. Altering gene expression to an extent where, the cell may not be able to fix it or a trait, which requires excessive energy loss escorts the organism’s gene regulation by breakdown of the introduced sequence over few generations. Events with constitutive overexpression may suffer poor performance over the years based on gene network prevailing in the crop of interest. Hence, network rewiring with minimal energy expenses is concerned.

THE INHERITANCE OF PATHOGENICITY IN RACES 111 AND 29 OF WHEAT STEM RUST

1969 ◽  
Vol 11 (2) ◽  
pp. 266-274 ◽  
Author(s):  
K. N. Kao ◽  
D. R. Knott
Keyword(s):  
Stem Rust ◽  
Rust Resistance ◽  
Single Gene ◽  
Stem Rust Resistance ◽  
Wheat Stem Rust ◽  
Complementary Genes

The inheritance of pathogenicity in wheat stem rust was studied in selfed cultures of races 29 and 111, F1 and F2 cultures of a cross between the two races and cultures from a backcross to race 29. The various cultures were tested on Marquis and Prelude and on a series of lines of these varieties carrying single genes for stem rust resistance. Virulence on Sr 5, Sr 6, Sr 8, Sr 9a, Sr 14 and a gene in Marquis was recessive and in each case there was a single gene for virulence corresponding to each gene for resistance. Virulence on Sr 1 was possibly controlled by two dominant complementary genes. There appeared to be two alleles for virulence on Prelude, one dominant and one recessive.

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