Study of Some Factors Influencing the Production of Durum Wheat Haploids by Cross Wheat x Maize

Crosses were carried out in Tunisia between seven genotypes of durum wheat used as female parent and a local population of maize as a male parent. Spikes were treated 24 h after pollination with different hormonal solutions containing 2,4-Dichlorophenoxyacetic acid (2,4-D), gibberellin (GA3) or silver nitrate (AgNO3). The production of haploid embryos was made using embryo rescue technique. Spikes were castrated manually or not castrated and then pollinated early before anthesis. Fruit setting, embryos formation, and regeneration of haploid plants were studied. The parental varieties 'Mahmoudi' and 'Khiar' gave the highest fruit setting rates 54.3 and 53.1%, respectively. The embryo rates were variable for parents and hybrids. The line 'LSA2' gave the highest regeneration rate (90%). The post-pollination treatment using 10 mg/l 2,4-D was the most favorable for fruit setting, embryos formation and haploid plant regeneration. The post-pollination treatment by spraying spikes by the hormonal solution was more favorable for fruit setting and embryos formation than soaking them in this solution.