Quantification of leaf rust resistance source in wheat germplasm in relation to epidemiological factors

Abstract EN

A comprehensive germplasm screening of 855 wheat advanced lines was conducted at wheat research institute, Ayub agricultural research institute, Faisalabad to identify new sources of leaf rust resistance during crop seasons 2015-2017.

in a primary evaluation, 112 advanced lines were selected having high phenotypic uniformity for further testing at wheat research institute, Faisalabad, a hotspot for leaf rust.

the second round of evaluation included 54 lines having durable type resistance against leaf rust.

assessment of epidemiological factors indicated great influence on the progress of leaf rust disease development.

minimum and maximum temperatures, relative humidity, rainfall and wind speed of 11-18.2°c, 23-33°c, 44-67%, 2-8.5 mm and 1.6-3.1 km/h respectively proved most conducive for leaf rust disease development.

avirulence to virulence formula showed that 7 Lr genes namely lr18, lr19, lr28, lr32, lr34, lr36 and lr23+ (Gaza) remained most effective at all four locations.

it was concluded that resistant wheat advanced lines and Lr genes identified under natural environmental conditions can be an excellent source to be deployed in breeding for disease resistance by incorporating such resistance genes into the background of high yielding wheat cultivars through molecular or conventional breeding methodology, and are expected to contribute toward food security at national and global levels.