Effects of media supplements on doubled haploid production in durum wheat

The efficiency of maize pollen induced doubled haploid (DH) production in durum wheat is low mainly because of poor germination of haploid embryos on culture media. The objective of this research was to investigate the effect of culture media supplements on DH production in durum wheat. Haploid durum embryos generated by the wheat x maize method from the cultivar Transcend and F-1 plants of a cross were cultured on a basic medium supplemented with 1mg L-1 3,6-dichloro-o-anisic acid (dicamba), 1mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D), 100 mg L-1 silver nitrate (AgNO3), 1mg L-1 6-benzylaminopurine (BAP), 1mg L-1 indole acetic acid (IAA), 1 mg L-1 naphthalene acetic acid (NAA), or 10 mg L-1 ascorbic acid. The proportion of haploid plantlets per embryo increased significantly by 33% with the AgNO3 supplemented medium over the basic medium, while the increase in proportion of doubled plants per embryo of 20% was not significant. The proportion of haploid plantlets was improved with BAP in the embryos of the F-1 plants, but the proportion of haploid plantlets and DHs per embryo produced with ascorbic acid and IAA were not different from the basic medium. Dicamba and NAA produced results less favorable than the control, and no germination occurred with 2,4-D. The advantage of AgNO3 was attributed to a reduction in the microbial contamination of embryos.