Initiating maize pre-breeding programs using genomic selection to harness polygenic variation from landrace...

Area of Science:

• Plant Breeding
• Genetics
• Agricultural Science

Background:

• Elite maize germplasm exhibits limited genetic diversity, posing challenges for breeding against new threats.
• Landrace diversity is crucial for overcoming genetic limitations in elite maize varieties.
• The Seeds of Discovery (SeeD) initiative aims to leverage landrace variation for maize improvement.

Purpose of the Study:

• To evaluate designs for initiating a maize pre-breeding program within the SeeD initiative.
• To assess methods for harnessing polygenic variation from landraces using genomic selection.
• To provide decision support for optimizing pre-breeding program design through stochastic simulation.

Main Methods:

• Stochastic simulation was used to evaluate various pre-breeding program designs.
• Factors assessed included initiation approach (landraces, doubled haploids, testcrosses), genetic parameters, and logistical constraints.
• Genomic prediction accuracy was analyzed across different design factors.

Main Results:

• Initiating pre-breeding programs directly from landraces is recommended over testcrosses.
• Testcross initiation can lead to rapid reconstruction of the elite donor genome.
• Genomic selection demonstrates significant power for pre-breeding programs with high genetic diversity and limited data recording resources.

Conclusions:

• Provides guidelines for the SeeD initiative and similar programs on initiating pre-breeding efforts.
• Emphasizes harnessing polygenic variation from landraces for robust maize breeding.
• Optimizes pre-breeding strategies through decision trees summarizing design factor effects.