Genomic Dissection of Leaf Angle in Maize (Zea mays L.) Using a Four-Way Cross Mapping Population

Area of Science:

• Plant genetics
• Agricultural science
• Maize breeding

Background:

• Optimizing plant architecture, particularly leaf angle, is crucial for increasing maize grain yield under high plant densities.
• Leaf angle significantly influences plant architecture and is a key target in modern maize breeding programs.

Purpose of the Study:

• To understand the genetic mechanisms underlying leaf angle variation in maize.
• To develop and utilize a novel four-way cross mapping population for quantitative trait loci (QTL) discovery.

Main Methods:

• Developed a four-way cross mapping population from four diverse maize inbred lines.
• Constructed linkage maps and performed QTL analysis using inclusive composite interval mapping (ICIM).
• Evaluated leaf angle in two environments and validated QTL in near-isogenic lines (NILs).

Main Results:

• Identified 14 QTL associated with leaf angle in maize.
• Validated four of these QTL in NILs.
• Seven QTL overlapped with known leaf angle genes/QTL, while seven were novel.

Conclusions:

• The four-way cross mapping strategy is effective for dissecting complex traits like maize leaf angle.
• This study provides valuable genetic resources for maize breeding aimed at improving plant architecture and grain yield.