Efficient callogenesis and plant regeneration in bread wheat (Triticum aestivum L.) varieties

Five bread wheat varieties (Triticum aestivum L.) were evaluated in vitro by culturing explants of scrapped mature embryos (ME) and endosperm-supported mature embryos (MES) on Murashige and Skoog (MS) medium fortified with 2, 3, and 4 mg/l of Dichlorophenoxyaceticacid (2,4-D) for callogenesis and proliferation. The regeneration was initiated first, on MS hormone-free and then continued on MS complemented with indoleacetic acid (IAA) and 6-benzyladenine (BAP). 2 mg.L-1 2,4-D was found to be optimum for callus induction and embryogenic callus production. As for plant regeneration, all five varieties have been able to form shoots and roots. However, this parameter was strongly controlled by variety and explant type. The highest percentages of regeneration were established at 80% for the endosperm-supported mature embryos and 68% for mature embryos. The success of any morphogenesis in vitro culture results from a better optimization of culture conditions (mineral and hormonal composition of the medium, explant type, and callus age).