Barley Doubled Haploid Plant Production by Anther Culture.

Barley is the fourth most cultivated cereal worldwide, traditionally used for animal feed and malt production. Its high adaptability to diverse environmental conditions is particularly evident in drought- and salt-prone areas. The development of resilient varieties is a priority to support food security and agricultural sustainability in the context of climate change. An important tool in barley breeding is the production of doubled haploid (DH) plants. This process enables the rapid development of homozygous plants in a single generation, significantly reducing the time required to release new varieties. DH technology has been widely adopted in the field of barley breeding, leading to the development of numerous new varieties. The two main methods for DH plant production in barley are interspecific crosses with Hordeum bulbosum and microspore embryogenesis (ME). The former involves the selective elimination of H. bulbosum chromosomes in the hybrid. In ME, microspores are reprogrammed to develop into embryos and finally into haploid or DH plants. Despite its high efficiency, ME faces challenges with certain genotypes, such as spring and six-row types. The barley anther culture protocol described in this chapter is based on the work of Cistué et al. (2003) with modifications to improve plant regeneration and root development. This protocol involves an osmotic and starvation treatment with mannitol for four days, followed by culture on an FHG solidified medium for embryo development, and a modified J25-8 medium for plant regeneration. A spontaneous doubling rate of 85%-90% has been achieved. This approach has enhanced the efficiency and cost-effectiveness of DH plant production in barley breeding programs.