Production of wheat doubled haploids via wide crosses in New Zealand wheat

Doubled haploid (DH) technology allows the production of homozygous cereal lines in a single generation. The integration of DH technology into New Zealand wheat (Triticum aestivum) breeding and genetics programmes has the potential to reduce the breeding time of new cultivars and improve our understanding of agronomically important genetic traits. Wheat x maize (Zea mays) crosses are now widely used in the production of wheat DHs. The aim of this study was to develop a wheat x maize method of DH production using New Zealand germplasm. A number of New Zealand wheat cultivars were crossed with different maize genotypes. A successful method for producing wheat DHs was achieved with all genotypes. Several factors were identified as being important in the efficiency of wheat DH production. These included: seasonal constraints, time of embryo excision, method of auxin application, and culture media composition. Of these factors, seasonal constraints were the major limitation in the use of the wheat x maize method for producing DHs in New Zealand.