Generation of Maize (Zea mays) Doubled Haploids via Traditional Methods

Commercial maize hybrid production has corroborated the usefulness of producing inbred lines; however, the delivery of new lines has always been a major time constraint in breeding programs. Traditional methods for developing inbred lines typically require 6 to 10 generations of self‐pollination to obtain sufficient homozygosity. To bypass the time and costs associated with the development of inbred lines, doubled haploid (DH) systems have been widely adopted in the commercial production of maize. Within just two generations, DH systems can create completely homozygous and homogeneous lines. A typical maize DH system, utilizing anthocyanin markers R1‐nj or Pl1 for haploid selection, is described in this protocol.