Adult plant resistance of wheat entries to black rust race 40-A

Genetic resistance is the most efficient, economical and environmental friendly approach against black rust of wheat. Although, evolution of new physiological races/pathotypes which can overcome the response of current resistant cultivar has engender to focus on evaluation of large number of wheat germplasms, breeding materials, cultivars for their reaction to black rust. Field based assessment for adult plant resistance in promising fifty entries against predominant pathotype 40-A of black rust revealed that forty eight entries showed resistance with lower AUDPC value in the range of 0 to 240 as compared to highly susceptible check varieties i.e. Lok 1 and Agra Local which showed AUDPC value of 1305 and 2000, respectively. But, amongst the forty eight resistant entries, forty entries showed durable resistance due to slower development of disease under high disease pressure which could be due to the presence of effective adult plant resistance Sr genes. Result of correlation coefficient between CI with both the disease parameters i.e. AUDPC (r=99**) and FRS (r=98**) also showed highly significant positive association.

Evolution of a new virulent race of black rust pose serious threat to wheat production

Adult plant resistance leads to less development of rust under high disease pressure

Slow rusters exhibit better field durability than those of vertical resistance genes only