Doubled haploid technology for line development in maize: technical advances and prospects.

Area of Science:

• Plant breeding and genetics
• Agricultural biotechnology

Background:

• Doubled haploid (DH) technology is crucial for modern maize breeding, offering advantages over conventional inbred lines.
• DH lines provide economic, logistic, and genetic benefits, driving their widespread adoption in commercial programs.

Purpose of the Study:

• To review advancements in maize doubled haploid (DH) production.
• To highlight how improved DH technologies increase efficiency and adoption in global maize breeding programs.

Main Methods:

• In vivo induction of maternal haploids using male haploid inducer genotypes.
• Identification of haploids from diploids using seed or seedling markers (e.g., R1-nj, red root, high oil).
• Chromosome doubling of haploid seedlings (D0) and selfing to produce fertile D0 plants.

Main Results:

• Development of haploid inducers with high induction rates and environmental adaptability boosts DH technology adoption, especially in tropical regions.
• New marker systems (red root, high oil) expand DH accessibility to diverse germplasm, including Flint, landrace, and tropical varieties.
• Automation in haploid identification and improved chromosome doubling protocols significantly reduce DH production costs and time.

Conclusions:

• Increased efficiencies in DH line production offer substantial benefits to maize breeding programs.
• Continuous advancements in DH technology are improving efficiency and driving its global adoption.
• Further research in chromosome doubling and automation promises even greater cost reductions and accessibility for DH technology.