Microspore embryogenesis in different hybrids of bread wheat (Triticum aestivum L) and improvement of embryogenesis efficiency via 2,4-D stress pre-treatment

The objective of this study was to improve induction of embryogenesis in bread wheat microspores. In this study, some F1 hybrids i.e M85-6 × 90, M85-8 × 90, mv17 × shiroudi, mv17 × kavir and kavir × bam were used. Microspores were cultured in A2 medium containing different amounts of maltose (60¬ & ¬90 ¬g/lit) depending on the genotype used. Analysis of variance for embryogenesis and regenerable embryos showed highly significant difference between hybrids but there was no significant difference between media (A2-60¬ &¬ A2-90) and interaction effects. M85-6 × 90, mv17 × Shiroudi and mv17 × kavir produced the highest ratio of embryogenesis among the hybrids. In regeneration phase, mv17 × Shiroudi and M85-6 × 90 had the highest frequency of regenerable embryos. The effect of 2,4-D as a novel stress for induction of microspores embryogenesis in Falat -known as the most responsive wheat cultivar to microspore culture technology, was investigated. Microspores were subjected to 2,4-D at 3 concentrations including 15, 25, 35 mg/l for 30 minutes while microspores without any stress treatment were used as the control. The embryogenesis of microspores stressed with 2,4-D were better than control. The highest yield of embryogenesis was produced at 15 mg/l 2,4-D. The most regenerated embryos were obtained in 15 & 25 mg/l of 2,4-D. According to the results obtained, 2,4-D is introduced as a new stress for induction of embryogenesis in microspores of wheat.