Barley Haploid Production Process

Haploid production in barley, particularly following interspecific hybridization, involves a specific sequence of biotechnological steps to achieve the desired outcome, often aiming for doubled haploids for breeding purposes.

Key Steps in Hybridization and Haploid Production

The typical process involves the following stages, matching the correct answer sequence:

1. Emasculation (C): This initial step involves the removal of anthers from the flowers of the maternal parent before they shed pollen. This prevents self-pollination and ensures that the subsequent pollination is controlled.
2. Pollen Collection and Cross Pollination (A): Pollen is collected from the desired paternal parent. This pollen is then used to pollinate the stigma of the emasculated maternal parent, establishing the interspecific cross.
3. Embryo Culture (B): Interspecific hybrids often have difficulties in embryo development or germination. Therefore, immature embryos or ovules containing the hybrid zygote are cultured in vitro on a suitable nutrient medium. This technique allows for the rescue and development of the hybrid embryo, leading to the formation of haploid plantlets.
4. Colchicine Treatment (D): The resulting haploid plants are typically sterile. To restore fertility and obtain homozygous diploid plants (doubled haploids), the haploid plantlets are treated with colchicine. Colchicine disrupts spindle formation during cell division, leading to chromosome doubling.

Therefore, the complete sequence for obtaining doubled haploids through interspecific hybridization in barley is Emasculation, Pollen collection and cross pollination, Embryo culture, and Colchicine treatment.