The effect of auxin and genotype on the production of Avena sativa L. doubled haploid lines

Production of doubled haploid (DH) cereals is becoming increasingly important in crop breeding programs, but the methods currently applied still remain inefficient. In this study, we present the procedure for obtaining haploid and DH oat plants by pollination with maize. Thirty-three oat genotypes were used in the experiments. Oat plants (14,543 florets) were pollinated with maize pollen 2 days after emasculation and treated with auxin analogues: 2,4-dichlorophenoxyacetic acid (2,4-D) or 3,6-dichloro-2-methoxybenzoic acid (dicamba), at a concentration of 100 mg dm⁻³. These auxins had no significant influence on the number of haploid embryos developed, but they significantly affected their germination ability, and thus haploid and DH plant production. After application of 2,4-D, 5.06 % of haploid embryos developed per emasculated florets, 1.37 % of haploid plants and 0.54 % of DH lines, whereas after dicamba treatment, 4.3 % of haploid embryos, 0.64 % of haploid plants and 0.25 % of DH lines. Haploid embryos were obtained from all genotypes tested, however, their frequency differed between individual genotypes. The highest number of embryos per emasculated florets (9.0 %) was obtained from the DC09040 genotype after dicamba treatment, and from STH123 × Skorpion (8.9 %) after 2,4-D treatment. The genotype did not significantly affect the development of haploid plants, nevertheless the highest number of DH lines was obtained from the Arab × Typhon genotype. There were 52 DH lines acquired from 28 genotypes, which produced a total of 5227 seeds. The number of seeds varied between the DH lines from 2 to 595. Seeds of all the DH lines produced fertile next generation. DH lines are currently included in breeding programs.