Recurrent selection for maydis leaf blight resistance and grain yield improvement in maize

Area of Science:

• Plant Breeding and Genetics
• Agricultural Science
• Crop Pathology

Background:

• Maydis leaf blight (MLB), caused by Bipolaris maydis, significantly limits maize production in Pakistan's plains.
• Developing resistant maize varieties is crucial for maintaining crop yields in affected regions.

Purpose of the Study:

• To estimate heritability, selection differentials, and response to selection for MLB resistance and grain yield in a maize population.
• To determine the progress achieved through S1 recurrent selection for improved disease resistance and yield.

Main Methods:

• Two cycles of S1 recurrent selection were performed on the Sarhad White (SW) maize population.
• 100 S1 lines were evaluated under artificial epiphytotics against MLB.
• Selection differentials, expected and observed responses, and heritability were calculated.

Main Results:

• Significant variations in MLB severity and grain yield were observed between selection cycles.
• Moderate to high heritability estimates were recorded for both traits.
• Blight severity decreased by 26% while grain yield increased by 19% per cycle.

Conclusions:

• S1 recurrent selection proved effective in simultaneously improving MLB resistance and grain yield in the SW maize population.
• Continued selection cycles may be necessary to further enhance yield and resistance levels.