The Effect of Light Intensity on the Production of Oat (Avena sativa L.) Doubled Haploids through Oat x Maize Crosses

Oat haploid embryos were obtained by wide crossing with maize. The effect of light intensity during the growing period of donor plants (450 and 800 mu mol m(-2) s(-1)) and in vitro cultures (20, 40, 70 and 110 mu mol m(-2) s(-1)) was examined for the induction and development of oat DH lines. Oat florets (26008) from 32 genotypes were pollinated with maize and treated with 2,4-dichlorophenoxyacetic acid. All the tested genotypes formed more haploid embryos when donor plants were grown in a greenhouse (9.4%) compared to a growth chamber (6.1%). The light intensity of 110 mu mol m(-2) s(-1) during in vitro culture resulted in the highest percentage of embryo germination (38.9%), conversion into plants (36.4%) and DH line production (9.2%) when compared with lower light intensities (20, 40 and 70 mu mol m(-2) s(-1)). The results show that the growth conditions of the donor plant and light intensity during in vitro culture can affect the development of haploid embryos. This fact may have an impact on oat breeding programs using oat x maize crosses.