The Genetic Basis of Natural Variation in Kernel Size and Related Traits Using a Four-Way Cross Population in Maize

Area of Science:

• Agricultural Science
• Genetics
• Plant Breeding

Background:

• Kernel size is a critical determinant of grain yield in maize.
• Understanding the genetic control of kernel size is essential for improving maize breeding programs.

Purpose of the Study:

• To investigate the genetic basis of natural variation in maize kernel size traits (length, width, thickness).
• To identify quantitative trait loci (QTL) associated with kernel size and other yield components.

Main Methods:

• Development of a four-way cross mapping population from four diverse maize inbred lines.
• Analysis of genetic variation in seed size and yield components (hundred kernel weight, row number, kernel number per row).
• Identification of QTLs using the developed mapping population.

Main Results:

• Ten QTLs significantly affecting kernel size were identified.
• Three of these QTLs, two for kernel length and one for kernel width, demonstrated stable expression across other maize yield components.
• Evidence suggests a genetic trade-off between kernel size and overall yield components.

Conclusions:

• The study elucidates the genetic architecture underlying kernel size variation in maize.
• Identified QTLs provide valuable targets for marker-assisted selection in maize breeding for enhanced yield.
• The findings contribute to understanding the genetic mechanisms governing yield component correlations.