Study On Double Haploid Production Of Wheat Between Wheat And Maize By Hybridization

Haploid embryo is obtained due to the chromosome elimination of maize between wheat(Triticum aestivum L.) and maize (Zea mays L.) by hybridization. Producing double haploid(DH)by young embryo culture and chromosome doubling is a high efficiency way to haploid breeding in wheat. The researchers has made an intensive study of this double haploid production way in recent years, but there are still some problem in producing haploid embryo, young haploid plant formation and chromosome doubling of haploid plants produced. The purpose of this study was to investigate a high and stable way of creating wheat DH plant by inducing wheat×maize haploid, using young haploid embryo isolated culture and chromosome doubling with 20ml/L Dimethyl Sulphoxide(DMSO)+500mg/L Colchicine(COL)solution(pH=5.0), apply the method producing double haploid of wheat though wheat×maize wide crosses to the winter wheat breeding veritably. Wide crosses has been done between three varieties of different genotype winter wheat and maize by three produced methods in order to gain haploid embryo of wheat, used five methods of hormone combined treatment and five volume concentrations of DMSO in 100mg/L 2,4-D solution in order to gain more haploid embryos of wheat under four environment conditions. The result was showed as follows:1. Both pollination and hormone treatment is prerequisite to producing haploid embryo of wheat.2. Haploid embryo of wheat all produced through winter wheat×maize wide crosses, but they had significant difference on the frequencies of embryo formation, Xiaoyan 22 was best in the greenhouse.3. The frequencies of embryo formation were different significantly in four kinds of different environment conditions, it was best in the greenhouse (10.9%).4. The frequencies of embryo formation induced by five methods of hormone combined treatment were not obvious different, it was better that using both 100mg/L 2,4-D and 100mg/L 2,4-D+30ml/L DMSO,and injecting into the stem was better than both dropping to the spikelet and simultaneously injecting into the stem in the second hormone treatment.5. The effect of five concentrations of DMSO solution to the frenquencies of embryo formation was different in field. DMSO enhanced the action of 2,4-D, was favourable to ovary growth and haploid embryo formation. In a certain concentration of DMSO, the higher is concentration of DMSO, the better was the frenquency of embryo formation.6. The effect of different haploid embryo ages on young haploid plant formation is also different in greenhouse, 15d was better than 16d. The 1/2MS medium without hormone in young haploid plant formation was better than the 2mg/LNAA+0.5mg/LKT+1/2MS medium, the frequency of young haploid plant formation was 50%.7.Soaking half of roots was better than soaking all of roots in chromosome doubling with 20ml/L DMSO+500mg/L COL solution(pH=5.0).