Identification of Yellow Rust Virulence Pattern on Wheat Germplasm in Relation to Environmental Conditions in Faisalabad

Abstract

One hundred and fifty varieties/lines were screened against stripe. Most of the varieties/lines showed reaction to these diseases. For the development of stripe rust disease of wheat artificial and natural inoculums was relied upon for infection and the environmental conditions of Ayub Agricultural Research Institute, Faisalabad were favorable. Out of 150 lines/varieties which were screened against sixty four lines/varieties were immune, resistance shown by 42 lines/varieties and remaining all were susceptible against yellow rust. Area under disease progress curve (AUDPC) of all varieties was calculated. The virulence and avirulence formula studied showed that 42 varieties of yellow rust were avirulent and 29 varieties were virulent by yellow rust fungi. Environmental factors had great effect on the progress of stripe rust diseases of wheat. A positive linear relationship between temperature (maximum, minimum) and disease severity showed that maximum stripe rust develops was highly recognized to 28-32 °C maximum and 14-18 °C minimum temperatures. While, other environmental factors like relative humidity, rainfall and wind speed showed positive correlation. On the basis of data these environmental factors were tested for correlation with stripe rust severities. It was concluded that screening and identifying the virulence pattern of yellow rust on wheat germplasm and utilizing these virulence genes on advanced lines may be helpful to produced for rust resistance in wheat to get maximum production.

Keywords: Yellow rust, Virulence Pattern, Resistance source, Epidemiology, Correlation