Development of a Haploid-Inducer Mediated Genome Editing System for Accelerating Maize Breeding

Area of Science:

• Plant breeding and genetics
• Agricultural biotechnology
• Crop improvement

Background:

• Generating pure inbred lines with multiple desired traits is crucial for crop breeding.
• Doubled haploid (DH) technology and CRISPR/Cas9 genome editing are powerful tools but have limitations for rapid elite line development.
• Conventional breeding for trait integration into elite backgrounds is time-consuming due to repeated crossing and backcrossing.

Purpose of the Study:

• To develop a novel Haploid-Inducer Mediated Genome Editing (IMGE) approach for accelerated crop breeding.
• To enable rapid generation of pure elite lines with integrated favorable agronomic traits.
• To overcome the limitations of existing DH and genome editing technologies in crop improvement.

Main Methods:

• Utilized a maize haploid inducer line equipped with a CRISPR/Cas9 cassette targeting a specific agronomic trait.
• Crossed the engineered haploid inducer line with an elite maize inbred line.
• Generated genome-edited haploids within the elite maize genetic background.

Main Results:

• Successfully developed the IMGE approach for efficient genome editing in haploid maize.
• Enabled the generation of homozygous pure doubled haploid (DH) lines with improved traits.
• Achieved trait improvement and homozygosity within two generations.

Conclusions:

• The IMGE approach significantly accelerates the development of pure elite crop lines with desirable traits.
• This method bypasses lengthy conventional breeding procedures, offering a more efficient breeding strategy.
• IMGE represents a game-changing technology for enhancing crop breeding speed and effectiveness.