Evidence for diploidy of a monokaryotic strain of Puccinia graminis f.sp. tritici

1975 ◽  
Vol 64 (1) ◽  
pp. 15-IN2 ◽  
Author(s):  
P.G. Williams
Keyword(s):  
Puccinia Graminis ◽  
Monokaryotic Strain

Histological studies on host-cell necrosis conditioned by the Sr6 gene for resistance in wheat to stem rust

1977 ◽  
Vol 55 (11) ◽  
pp. 1445-1452 ◽  
Author(s):  
D. J. Samborski ◽  
W. K. Kim ◽  
R. Rohringer ◽  
N. K. Howes ◽  
R. J. Baker
Keyword(s):  
Triticum Aestivum ◽  
Stem Rust ◽  
Fungal Growth ◽  
Triticum Aestivum L ◽  
Host Cells ◽  
Puccinia Graminis ◽  
Near Isogenic Lines ◽  
Cell Necrosis ◽  
Calcofluor White ◽  
Histological Studies

Seedlings of resistant (Sr6) and susceptible (sr6) near-isogenic lines of wheat (Triticum aestivum L.) were inoculated with a race of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) that was avirulent on the line with Sr6 and they were kept at 19, 25, 26, and 27 °C. Fluorescence microscopy was used to detect autofluorescing necrotic host cells and rust colonies after these were stained with a fiuorochrome (Calcofluor White M2R New).In leaves containing the Sr6 gene, a smaller percentage of colonies grown at 25 °C had necrotic cells associated with them than those that were grown at 19 °C. The incidence of colony-associated necrosis in these leaves could be further reduced by increasing the temperature to 26 °C and 27 °C. Similarly, the number of necrotic host cells per colony decreased with an increase in temperature. Colonies in genotypically resistant leaves were usually smaller than those in genotypically susceptible leaves, but the differences in colony sizes between these two lines decreased at the higher temperatures.When infected plants containing the Sr6 gene were kept for varying times at 25 °C and then were transferred to 19 °C, there was significantly less fungal growth and more necrosis than in plants kept continuously at 25 °C. This necrosis occurred largely in those cells that were invaded after the transfer to 19 °C, when the Sr6 gene was activated.

scholarly journals Seedling Stage Resistance of Iranian Bread Wheat Germplasm to Race Ug99 of Puccinia graminis f. sp. tritici

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Mohsen Mohammadi ◽  
Davoud Torkamaneh ◽  
Mehran Patpour
Keyword(s):  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Wheat Cultivars ◽  
Breeding Lines ◽  
Wheat Germplasm ◽  
Stem Rust Resistance Genes ◽  
Rust Resistance Genes

Following emergence of Ug99, the new virulent race of Puccinia graminis f. sp. tritici in Africa, a global effort for identification and utilization of new sources of Ug99-resistant germplasm has been undertaken. In this study, we conducted replicated experiments to evaluate the resistance of Iranian wheat germplasm to the TTKSK lineage of the Ug99 race of P. graminis f. sp. tritici. We also evaluated for presence of stem rust resistance genes (i.e., Sr2, Sr24, Sr26, Sr38, Sr39, Sr31, and Sr1RSAmigo) in wheat cultivars and breeding lines widely cultivated in Iran. Our phenotyping data revealed high levels of susceptibility to Ug99 in Iranian bread wheat germplasm. Our genotyping data revealed that Iranian cultivars do not carry Sr24, Sr26, or Sr1RSAmigo. Only a few salt-tolerant cultivars and breeding lines tested positively for Sr2, Sr31, Sr38, or Sr39 markers. In conclusion, the genetic basis for resistance to Ug99 in Iranian wheat cultivars was found to be vulnerable. Acquiring knowledge about existing resistance genes and haplotypes in wheat cultivars and breeding lines will help breeders, cereal pathologists, and policy makers to select and pyramid effective stem rust resistance genes.

VIRULENCE OF THE NORTH CAUCASIAN POPULATION OF PUCCINIA GRAMINIS PERS. F. SP. TRITICI

1970 ◽  
pp. 40-45
Author(s):  
G. V. Volkova ◽  
Е. V. Gladkova ◽  
O. O. Miroshnichenko
Keyword(s):  
High Efficiency ◽  
Caucasian Population ◽  
Puccinia Graminis ◽  
North Caucasus ◽  
Wheat Varieties ◽  
Caucasus Region ◽  
Pathogen Virulence ◽  
The North ◽  
New Varieties ◽  
Wheat Lines

The aim of the study was to monitor the virulence of Puccinia graminis Pers. f. sp. tritici in the North Caucasus.  The objectives of the study were to collect P. graminis infectious material from sown winter wheat varieties and evaluate the long-term dynamics of the pathogen virulence in the North Caucasus region in 2014-2019. As a result, an analysis of the virulence of the stem rust pathogen population of wheat collected in Krasnodar, Stavropol Territories, and Rostov Region was carried out. 81 mono-empty mushroom isolates were isolated and differentiated.  The genes Sr5, Sr31, Sr38 were characterized by high efficiency.  On the lines with the genes Sr7b, Sr8b, Sr9f, Sr9g, Sr10, Sr11, Sr12, Sr13, Sr14, Sr21, Sr22, Sr23, Sr26, Sr29, Sr32, Sr33, S35, Sr37, SrDp2, SrWLD, a variation in the virulence frequencies of P. graminis was observed.  Significant changes (in the direction of increasing occurrence) in the North Caucasian population 2014-2019  the pathogen was noted in the frequency of clones virulent to wheat lines with resistance genes Sr11, Sr21, Sr22, Sr26, Sr32, Sr33. A decrease in the frequency of clones virulent to Sr8b, Sr9g, Sr10, Sr12, Sr14, Sr35. At approximately the same level, the occurrence of clones virulent to the genes Sr6, Sr7a, Sr8а, Sr9a, Sr9b, Sr9d, Sr9e, Sr13, Sr15, Sr16, Sr17, Sr19, Sr20, Sr24, Sr25, Sr27, Sr30, Sr36, Sr39, Sr40, Sr44, SrGt, SrTmp. Effective genes that have shown their resistance to P. graminis in the seedling phase are proposed for use in breeding in southern Russia to create new varieties of wheat.

Importance of diseases in herbage seed production

1980 ◽  
Vol 1 ◽  
pp. 36-40
Author(s):  
G.C.M. Latch
Keyword(s):  
Seed Production ◽  
Control Measures ◽  
Puccinia Graminis ◽  
Minor Importance ◽  
Farming Practices ◽  
Head Smut ◽  
Yield And Quality ◽  
Suggested Keywords ◽  
Production Diseases

Yield and quality of herbage seed can be affected by many diseases. In New Zealand the most important diseases of grasses are rusts, especially stem rust on ryegrasses, cocksfoot and timothy; head smut of bromes; and ergot of paspalum. Blind-seed disease is of minor importance on ryegrass at present. Clover yield can be affected by rot, scorch and stem nematode. These diseases and others are discussed in relation to changing farming practices, and disease control measures are suggested. Keywords: Herbage seed production, diseases, Puccinia graminis, Ustilago bullata, Claviceps paspali, Gloeotinia temulenta

scholarly journals Melhoramento do trigo: XXI. Avaliação de linhagens em diferentes regiões paulistas

Bragantia ◽  
1989 ◽  
Vol 48 (1) ◽  
pp. 53-71 ◽  
Author(s):  
Carlos Eduardo de Oliveira Camargo ◽  
João Carlos Felício ◽  
Antonio Wilson Penteado Ferreira Filho ◽  
José Guilherme de Freitas ◽  
Benedito de Camargo Barros ◽  
...  
Keyword(s):  
Puccinia Graminis

Foram comparadas entre si vinte e três linhagens e dois cultivares comerciais de trigo através de ensaios instalados em diferentes regiões paulistas, em 1984/86, analisando-se a produtividade, características agronômicas, resistência às doenças e tolerância ao alumínio. Considerando os ensaios conduzidos em Capão Bonito, a linhagem 19 destacou-se quanto à produção de grãos, como moderadamente resistente à helmintosporiose, muito tolerante à toxicidade de Al3+, ciclo precoce e, apesar do porte alto, boa resistência ao acamamento. Nos ensaios do Vale do Paranapanema (Cruzália e Cândido Mota), sobressaíram o cultivar BH-1146 e a linhagem 16 quanto à produção de grãos. A linhagem 16 apresentou porte baixo, ciclo precoce, resistência de campo à ferrugem-da-folha, resistência ao acamamento e tolerância ao Al3+ e, em Tietê, foi a mais produtiva. No ensaio de Campinas, não foram detectadas diferenças entre os tratamentos quanto à produção de grãos. As linhagens 1, 3, 9, 10, 11, 15, 16, 22 e 23 e o cultivar Alondra-S-46 mostraram plantas de porte semi-anão, diferindo significativamente do 'BH-1146', de porte alto. Em relação à ferrugem-do-colmo (Puccinia graminis f. sp. tritici), as linhagens 9, 10 e 11 e o 'Alondra-S-46' foram resistentes às seis raças testadas em estádio de plântula em casa de vegetação. Em condição de infecção natural no estádio de planta adulta, as linhagens 11, 16 e 18 e o 'BH-1146' apresentaram menor grau de infecção de ferrugem-da-folha (P. recondita). A linhagem 7, com espigas compridas, 7 e 8, com maior número de espiguetas por espiga, 2, com grande fertilidade nas espigas, e 21, com grãos mais pesados, representaram boas fontes genéticas dessas características ao programa de melhoramento. As linhagens 1, 3, 5, 12, 13, 14, 16, 17, 18, 19 e 21 e o cultivar BH-1146 foram tolerantes à presença de 10mg de Al3+/litro em solução nutritiva.

AC Nordic orchardgrass (Dactylis glomerata L.)

1993 ◽  
Vol 73 (3) ◽  
pp. 845-846 ◽  
Author(s):  
A. R. McElroy
Keyword(s):  
Key Words ◽  
Stem Rust ◽  
Dactylis Glomerata ◽  
Research Centre ◽  
Mass Selection ◽  
Puccinia Graminis ◽  
Plant Research ◽  
Selection For ◽  
Dactylis Glomerata L

AC Nordic is a late-maturing orchardgrass (Dactylis glomerata L.) cultivar. It was developed by mass selection for yield, persistence and resistance to stem rust (Puccinia graminis) at the Plant Research Centre, Agriculture Canada, Ottawa. Its yield was similar to that of cv. Sumas in a total of 33 station years in Quebec. Yield in second and subsequent production years was 101.6% of cv. Sumas over 19 station years. Key words: Dactylis glomerata L., orchardgrass

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