Journal ArticleDOI
Current status, likely migration and strategies to mitigate the threat to wheat production from race Ug99 (TTKS) of stem rust pathogen
Ravi P. Singh,David Hodson,Yue Jin,Julio Huerta-Espino,Miriam G. Kinyua,Ruth Wanyera,P. Njau,Richard W. Ward +7 more
TLDR
A Global Rust Initiative has been launched to monitor the further migration of this race, facilitate field testing in Kenya or Ethiopia of wheat cultivars and germplasm developed by wheat breeding programmes worldwide, understand the genetic basis of resistanceespecially the durable type, carry out targeted breeding to incorporate diverse resistance genes into key cultivar and Germplasm, and enhance the capacity of national programmes.Abstract:
Stem or black rust, caused by Puccinia graminis tritici, has historically caused severe losses to wheat (Triticum aestivum) production worldwide. Successful control of the disease for over three decades through the use of genetic resistance has resulted in a sharp decline in research activity in recent years. Detection and spread in East Africa of race TTKS, commonly known as Ug99, is of high significance as most wheat cultivars currently grown in its likely migration path, i.e. to North Africa through Arabian Peninsula and then to Middle East and Asia, are highly susceptible to this race and the environment is conducive to disease epidemics. Identifying/developing adapted resistant cultivars in a relatively short time and replacing the susceptible cultivars before rust migrates out of East Africa is the strategy to mitigate potential losses. Although several alien genes will provide resistance to this race, the long-term strategy should focus on rebuilding the ‘Sr2-complex’ (combination of slow rusting gene Sr2 with other unknown additive genes of similar nature) to achieve long-term durability. A Global Rust Initiative has been launched to monitor the further migration of this race, facilitate field testing in Kenya or Ethiopia of wheat cultivars and germplasm developed by wheat breeding programmes worldwide, understand the genetic basis of resistanceespecially the durable type, carry out targeted breeding to incorporate diverse resistance genes into key cultivars and germplasm, and enhance the capacity of national programmes. A few wheat genotypes that combine stem rust resistance with high yield potential and other necessary traits have been identified but need rigorous field testing to determine their adaptation in target areas.read more
Citations
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Journal ArticleDOI
The emergence of Ug99 races of the stem rust fungus is a threat to world wheat production
Ravi P. Singh,David Hodson,Julio Huerta-Espino,Yue Jin,Sridhar Bhavani,P. Njau,S. A. Herrera-Foessel,Pawan K. Singh,Sukhwinder Singh,Velu Govindan +9 more
TL;DR: Although new Ug99-resistant varieties that yield more than current popular varieties are being released and promoted, major efforts are required to displace current Ug99 susceptible varieties with varieties that have diverse race-specific or durable resistance and mitigate the Ug99 threat.
Journal ArticleDOI
Association analysis of historical bread wheat germplasm using additive genetic covariance of relatives and population structure
José Crossa,Juan Burgueño,Susanne Dreisigacker,Mateo Vargas,S. A. Herrera-Foessel,Morten Lillemo,Ravi P. Singh,Richard Trethowan,Marilyn L. Warburton,Jorge Franco,Matthew P. Reynolds,Jonathan H. Crouch,Rodomiro Ortiz +12 more
TL;DR: Mapped diversity array technology markers were used to find associations with resistance to stem rust, leaf rust, yellow rust, and powdery mildew, plus grain yield in five historical wheat international multienvironment trials from the International Maize and Wheat Improvement Center.
Book ChapterDOI
Will Stem Rust Destroy the World’s Wheat Crop
Ravi P. Singh,David Hodson,Julio Huerta-Espino,Yue Jin,P. Njau,Ruth Wanyera,S. A. Herrera-Foessel,Richard W. Ward +7 more
TL;DR: The proposed strategy is to deploy spring wheat varieties possessing durable, adult plant resistance in East Africa and other primary risk areas to reduce inoculum and selection of new virulences capable of overcoming undefeated race-specific resistance genes.
Journal ArticleDOI
Detection of virulence to resistance gene Sr24 within race TTKS of Puccinia graminis f. sp. tritici.
TL;DR: The North American stem rust nomenclature system is proposed to be revised by the addition of four genes (Sr24, Sr31, Sr38, and SrMcN) as the fifth set and differentiates isolates within race TTKS into two separate races: TTKSK and TTKST, with avirulence and virulence on Sr24, respectively.
Journal ArticleDOI
The coffee rust crises in Colombia and Central America (2008–2013): impacts, plausible causes and proposed solutions
Jacques Avelino,Marco Cristancho,Selena Georgiou,Pablo Imbach,Lorena Aguilar,Gustavo Bornemann,Peter Läderach,Francisco Anzueto,Allan J. Hruska,Carmen Morales +9 more
TL;DR: Coffee rust is a leaf disease caused by the fungus, Hemileia vastatrix as mentioned in this paper, which has affected coffee production in Colombia, Central America and Mexico, from 2008 to 2011, and Peru and Ecuador in 2013.
References
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Book
Catalogue of gene symbols for wheat
TL;DR: The University of Sydney, Plant Breeding Institute Cobbitty, PMB 11, Camden, N.W., Australia, 2570, bobm@camden.usyd.edu.au National Institute of Genetics, 111 Yata Mishima, Shizuoka 411-8540 Japan.
Journal ArticleDOI
A diagrammatic scale for estimating rust intensity on leaves and stems of cereals
TL;DR: The Cobb scale and the modified Cobb (U.S.D.A.) scale were devised for estimating, by means of diagrams, the proportion of the area of a leaf or stem occupied by rust pustules, are presented, providing a basis for more objective and accurate determinations.
Book
Rust diseases of wheat: Concepts and methods of disease management
TL;DR: A partir de las obras de Tozzeni y Fontana en 1767, existe una lista muy extensa de publicaciones cientificas sobre los agentes patogenos of las royas, las enfections that provocan and the resistencia a ellas as mentioned in this paper.
Journal ArticleDOI
Aerial Dispersal of Pathogens on the Global and Continental Scales and Its Impact on Plant Disease
TL;DR: The strongly stochastic nature of long-distance dispersal causes founder effects in pathogen populations, such that the genotypes that cause epidemics in new territories or on cultivars with previously effective resistance genes may be atypical.