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.