Combating Ug99 - Current Scenario

Abstract

The yield potential of wheat crop is not achieved abundantly because of disease pressure. One of the most destructive of such diseases is stem rust (SR). SR caused by Puccinia graminis f. sp. tritici (Pgt), had been controlled successfully during three decades throughout the world with deployment of semi-dwarf resistant cultivars in the last half of previous century. During 1999 appearance and dispersion of stem rust race Ug-99 in Uganda (a virulent race against Sr31) created an alarming situation worldwide. Widespread germplasm was protected by gene Sr31 found susceptible to this terrible strain as the gene was protecting 80% wheat lines cultivated throughout planet. The emergence of the Ug99 race of stem rust in Africa and the Middle East together with the appearance of new strains in Europe catalyzed a main effort to recognize sources of stem rust resistance genes against new virulent strains and incorporate these genes into wheat lines. Scientific community addressed the dilemma in time and efforts did not go waste. Worldwide concern regarding the danger to global wheat production caused by Ug99 led to breeding wheat for durable resistance against disease and achieved considerably. This success is attributed to team work of experts and serves as an example for research workers in future. However, the continued emergence of stem rust variants that overcome new resistance genes, demands an amplified emphasis on pathogen evolution and virulence mechanisms. A major role for BGRI is to keep ‘the eye on the ball’ with regard to all these aspects. This article enables us to design strategy to tackle a situation which appears without alarm but in this case intellectuals coordinated each other and solution became possible. The same principle does not apply in plant pathology but in Human pathology and Veterinary pathology.

Unraveling the Genetic and Geographic Diversity of Puccinia striiformis f. sp. Tritici (Pst) Populations for Effective Control of Stripe Rust in Global Wheat Production

“…Rust pathogens: A threat to wheat production Rust pathogens are a significant concern for wheat production (Ijaz et al, 2023). These pathogens are known to cause severe damage to crops, posing a constant threat to the production of wheat (Afzal et al, 2021(Afzal et al, , 2022a. The rust pathogens of wheat are considered to be among the most important crop pathogens due to their ability to spread quickly and infect entire fields, leading to significant yield losses (Afzal et al, 2015(Afzal et al, , 2022b.…”

“…These pathogens are known to cause severe damage to crops, posing a constant threat to the production of wheat (Afzal et al, 2021(Afzal et al, , 2022a. The rust pathogens of wheat are considered to be among the most important crop pathogens due to their ability to spread quickly and infect entire fields, leading to significant yield losses (Afzal et al, 2015(Afzal et al, , 2022b. The disease caused by these pathogens is commonly referred to as rust, which appears as small, yellowish-orange pustules on the leaves, stems, and other parts of the plant.…”

Identification of Quantitative Trait Loci for Leaf Rust and Stem Rust Seedling Resistance in Bread Wheat Using a Genome-Wide Association Study

“…The stem rust resistance genes Sr11 , Sr13 , Sr22 , Sr26 , Sr31 , Sr33 , and Sr35 were confirmed to be effective against all Pgt races found in Kazakhstan. Although Ug99 has not been observed in Kazakhstan yet [ 15 ], recent reports have indicated the spreading of this race in the Middle East and a potential scenario of migration to Central and South Asia [ 5 , 29 ]. In Kazakhstan, 25 races of Pt were identified based on the assessments in all major wheat-growing regions of the country in 2018.…”